E-paper_E-book

e-Paper & e-Book

MASSIMO MARRAZZO -

BIODOMOTICA速

Technology for e-Books readers B/W & Colors displays

Nanotechnology VOL. 2 2011 Massimo Marrazzo - biodomotica.com 1

e-Paper & e-Books

Inch (plural: inches) Abbreviation or symbol: in or ″ A unit of length in the U.S. Customary and British Imperial systems, equal to 1/12 of a foot (2.54 centimeters).

1 inch = 1" = 2.54 cm mm: Millimeter 1mm = 0.1 cm = 0.0394 inches cm: Centimeter 1cm= 10 mm = 0.3937 inches 2

MP: Megapixels, 1 MP = 1,024 pixels = 1,048,576 pixels What is decimal notation?

5.5 rather than 5 and a half (or 5 1/2) It means that you represent fractions of numbers in tenths (and hundredths, thousandths, etc) rather than in fractions (or in eighths or twelfths or some such).

The above notation would be expected in the US. However, in Europe, the notation would be 5,5 for 5 and a half. Basically, the Europeans reverse the use of comma and period in their decimal notation. http://lamar.colostate.edu/~hillger/faq.html http://lamar.colostate.edu/~hillger/

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Index Definition of an e-book Ecology of e-readers E-paper and human vision iPhone Retina display Compare display resolution E-paper technologies reference guide LCD Bistable LCD Transparent TFT LCD IPS LCD Super PLS LCD Pentile Subpixel Rendering Cholesteric LCD Technology OLED vs TFT-LCD Technology Bichromal Technology Electrophoretic Technology QR-LPD Colored Electrophoretic Technology Electrowetting Technology Electrofluidic Technology Electrochromic Technology Interferometric Modulator Technology Photonic Crystal Technology OLED Transparent OLED AMOLED Super AMOLED QDLED Flexible Displays Human_computer Interaction Touchscreen Laser Projection Keyboard Braille e-Books Volumetric displays 3-D hologram movie 3D display Autostereoscopic display Acronyms Links

Pag. 4 5 7 18 24 31 35 41 44 46 48 49 51 52 58 62 64 70 72 78 84 91 93 99 101 108 115 119 120 123 132 136 149 151 154 158 162 166 172 175

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What is an e-Book?

E-book: electronic book The term e-book is often used without distinction to indicate concepts much different: e-book: electronic book (the text or images I read) e-book reader device: the device that makes possible the use of electronic book, the hardware that supports the readers software. It can be either a device dedicated, designed and built exclusively for reading e-book, or of any other electronic apparatus, which a tablet-PC, a handheld, a notebook etc. e-book reader: software for the reading of e-book. Examples of e-book readers are Adobe Reader, Microsoft Reader and Amazon's proprietary, DRM-restricted format http://ebookmall.com/choose-format/ e-book format: The file type with which it is saved the contents of the e-book. Accessible through the special software (e-book reader), which saved the content of e-book; these formats have visualization features, formatting, navigation and protection more advanced than the most common digital formats for storing the texts (TXT, EPUB, DOC, RTF, PDF, LIT, AZW).

You should talk about e-book reader only referring to those devices equipped with features such that they can emulate reading a book paper.

The e-book readers combine the portability of handhelds with higher resolution of the screen; large like a book of average size, weigh a few hundred grams and surface area is occupied, almost entirely, by a screen with a very high definition, in white and black or, in the models most evolved in color.

Electronic books are excellent to encyclopedias, technical documentation, brochures, catalogues, magazines and comics, because they age soon or are continuously updating.

Think at comics, with a new episode every week or every month. The previous episodes can be stored digitally without occupy space and without crumple.

E-paper: electronic paper: A display technology that mimics the appearance of ordinary ink on paper.

E-paper uses an electronic ink (e-ink) to display the text or images which has the ability to hold the text indefinitely without drawing any power. Electricity is only used when changing the text or images. Electronic paper is not digital paper, which is a pad to handwritten digital documents with a digital pen.

E-ink: an electronic ink technology for e-paper displays manufactured by the E Ink Corporation. Almost all ebook readers use the e-ink technology due to its superior paper-like quality, non-backlit screen that allows readability under sunlight and eliminates eye-strain, and saves energy as it doesn't require electricity to hold images on screen.

Paper-like: of or like paper (paper-like display) Traditional books: books printed on paper

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Ecology of E-readers - http://cleantech.com/news/4867/cleantech-group-finds-positive-envi Cleantech Group report: E-readers a win for carbon emissions August 19, 2009 - by Lisa Sibley, Cleantech Group

New report conducts lifecycle analysis of Amazon’s Kindle, suggesting significant environmental advantages compared to the publishing of books, magazines and newspapers.

Only time will tell if electronic book readers are to become a new standard in the future. But the Cleantech Group takes an in-depth look at the environmental impact of the devices in its recent lifecycle analysis.

The new study finds that e-readers could have a major impact on improving the sustainability and environmental impact on the publishing industry, one of the world’s most polluting sectors. In 2008, the U.S. book and newspaper industries combined resulted in the harvesting of 125 million trees, not to mention wastewater that was produced or its massive carbon footprint.

The Cleantech Group’s report, The environmental impact of Amazon's Kindle, suggests that e-readers are still a niche technology, with a little more than 1 million units sold to date. So they really haven’t had much impact on the environment, be it good or bad.

But with sales projected to see an uptick, reaching to 14.4 million in 2012, the report looks at the emissions that devices like the market leader, Amazon’s Kindle, could produce and prevent.

The report indicates that, on average, the carbon emitted in the lifecycle of a Kindle is fully offset after the first year of use.

The report, authored by Emma Ritch, states: "Any additional years of use result in net carbon savings, equivalent to an average of 168 kg of CO2 per year (the emissions produced in the manufacture and distribution of 22.5 books)."

In the United States, Amazon currently holds a 45 percent market share of e-reader devices, with one main competitor Sony trailing at 30 percent.

The Cleantech Group forecasts that e-readers purchased from 2009 to 2012 could prevent 5.3 billion kg of carbon dioxide in 2012, or 9.9 billion kg during the four-year time period.

However, there are obstacles to overcome for the devices and their content to reach its full potential, the reports suggests.

The publishing industry would need to put standards in place to help speed adoption of the technology.

Reductions in emissions are also dependent on the publishing industry decreasing its production of physical books, according to the report.

The report also encourages academic institutions to implement pilot testing of e-readers as a replacement to physical textbooks, citing schools such as Princeton University, the University of Virginia, and Arizona State University already leading the way.

The Cleantech Group’s full report on e-readers can be downloaded by subscribers here. http://cleantech.com/research/kindlebrief.cfm Copyright © 2009 Cleantech Group LLC. All rights reserved, including right of redistribution.

- http://www.einkcorp.com/green.html

There are 6 billion electronic displays in mobile devices, computers and signage worldwide consuming 2,300,000 Megawatt Hours. E Ink Displays save 60% energy vs. LCD.

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Electronic Paper Displays vs. LCD Displays You've heard the old saying, "a penny saved is a penny earned." The same is true of power in the portable device sector; the more power one can save, the more one earns in terms of performance, size and weight.

Why? Consider that, on average, A 12” LCD-equipped device uses, in 20 hours, the equivalent of 36 AA batteries while an E Ink 12-inch display uses just one battery's worth. What this means is that the power supply for an E Ink equipped device can weigh a few ounces as opposed to a few pounds when it comes to its equivalent LCD counterpart. The ramifications for product design are dramatic.

Explained another way, under normal usage conditions, an E Ink enabled reader will last three weeks on a single charge while an LCD-based display will need to be recharged after just one and a half days. If you could apply such a dramatic increase in power efficiency to the automobile, that would be like running for six months on a single tank of gas. ePaper vs. Printed Paper The benefits of E Ink over the printed page can easily be measured in the size of the consumer's carbon footprint. First, we all know that trees breathe in CO2. But did you know that a single tree can remove about one metric ton of CO2 from the air every year? On average, each harvested tree produces 173 reams if paper. Therefore, each ream of paper is the equal to roughly 12 pounds of CO2 that will not be removed 1 from the atmosphere every year.

The numbers become more and more compelling from there. In 2004, world paper production was equal to 1 359 million metric tons, emitting 74 million metric tons of CO2 in its production. We throw away 2 approximately one billion trees worth of paper each year, and a portion of that paper is incinerated, creating 2 more carbon emissions. One Sunday's worth of newspapers require the cutting of 500,000 trees .

Conversely, a study out of the University of California Berkeley shows that reading a newspaper electronically releases 32 to 140 times less CO2 and uses 27 times less water than reading the paper 3 version. In short, the difference between electronic ink and printed paper could have a dramatic effect on CO2 in the atmosphere in just one day. If we could replace all paper newspapers with eNewspapers 4 1 tomorrow, 95 million trees that would remove 98 million tons of greenhouse gas every year could be saved.

1 James DeRosa, Global Warming Initiatives, Inc. 5/3/2007 www.greenpdf.com 2 www.recycling-revolution.com 3 Vivian Song, Electronic Ink, Paperless Display Technology Saves Trees and The Environment, 2010 Toronto Sun.com 4 New Generation of e-book Readers Contributes to Environmental Protection, 7/20/09 Digital Book Readers.com

- www.globis.ethz.ch/education/past_seminars/2006-2007/cscw/presentation_09_01_displayTechnologies.pdf Display technologies in comparison CSCW Seminar – Andreas Hasler andhasle@student.ethz.ch CRT 2 Power consumption 700 W/m Resolution 130 ppi

LCD PDP 2 2 400 W/m 700 W/m 200 ppi 100 ppi

E-Ink Paper 2 2 0-50 W/m 0 W/m 200 dpi 1200* dpi

Weight

Very high

High

High

Low

Flexibility

unportable

portable

portable

paper-like

Contrast (ratio)

---

2‘000:1

20‘000:1** ---

---

Yes No

Yes No

Yes No

No Yes

Light emitting Image persistence *with a laserprinter **Questionable value

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No Yes

Low paper

e-Paper & e-Book

e-Paper & Human Vision -

http://desktoppub.about.com/cs/intermediate/a/meas_resolution.htm

SPI, PPI, DPI, LPI Demystified Most users can comfortably reading off screen. Reading from a screen is usually confined to quick scan reading and searching for information, rather than careful in depth reading. Consequently most will opt for printing a page that they wish to read carefully.

Most conventional computer displays today have a resolution of between 70 and 100ppi (pixels per inch PPI). A standard laser or ink jet printer will print using a resolution of between 300 and 600ppi.

E-paper improve readability of electronic documents because it have: - High resolution (150dpi or better).

- High contrast, equal to that of print on paper (about 10:1 or better).

- Stable image which results in less strain on the eyes - Readable in any ambient light conditions - Readable at any viewing angle - Large area (at least A4 format) One of the most confusing aspects of desktop publishing is resolution and the measurement of resolution: SPI, PPI, DPI, and LPI. Often DPI is used in place of SPI and PPI although they aren't really the same. That only makes it more confusing. But it need not be. Here are the short definitions for each term.

SPI (samples per inch) is scanner and digital image resolution. To scan an image, the scanner takes a sampling of portions of the image. The more samples it takes per inch, the closer the scan is to the original image. The higher the resolution, the higher the SPI. PPI (pixels per inch) is the number of pixels displayed in an image.

A digital image is composed of samples that your screen displays in pixels.

The PPI is the display resolution not the image resolution.

DPI (dots per inch) is a measure of the resolution of a printer. It properly refers to the dots of ink or toner used by an imagesetter, laser printer, or other printing device to print your text and graphics. In general, the more dots, the better and sharper the image. DPI is printer resolution.

LPI (lines per inch) refers to the way printers reproduce images, simulating continuous tone images by printing lines of halftone spots. The number of lines per inch is the LPI, sometimes also called line frequency.

You can think of LPI as the halftone resolution.

- http://jura.wi.mit.edu/bio/graphics/scanning/resolution.php

Resolution Resolution is determined by the size of the units of information representing an image. A pixel is a unit of information displayed on a monitor. Each pixel holds a defined amount of information stored on your disk. An image of a given area will become more detailed as more pixels are used to describe it.

Resolution can be measured in many ways: 1. Samples per inch (spi, scanners) 2. Pixels per inch ( ppi monitors) 3. Dots per inch (dpi, printers) Massimo Marrazzo - biodomotica.com 7

e-Paper & e-Books More pixels in a given area will give you a smoother, more detailed image but it will also give you a much larger file.

Fortunately, as the pixels become smaller and smaller, the difference between high resolution and extremely high resolution are not discernible by the human eye, and are not reproducible on our printers (although a professional printing press is capable of much higher resolution than our printers here).

The key is to find the point at which you no longer get a benefit from additional resolution. For output to Whitehead devices, that point is between 300 and 400 ppi.

We often use dpi as a generic term, but that isn't accurate. Sometimes a printer (such as laser printers) will use several dots of different colors to make the color of one pixel of an image. This is why even though a printer may have a 600 dpi capability, it doesn't mean the same thing as 600 ppi resolution.

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e-Paper & e-Book - http://www.ndt-ed.org/EducationResources/CommunityCollege/PenetrantTest/Introduction/visualacuity.htm

Visual Acuity of the Human Eye The eye has a visual acuity threshold below which an object will go undetected. This threshold varies from person to person, but as an example, the case of a person with normal 20/20 vision can be considered. As light enters the eye through the pupil, it passes through the lens and is projected on the retina at the back of the eye. Muscles called extraocular muscles, move the eyeball in the orbits and allow the image to be focused on the central retinal or fovea.

The retina is a mosaic of two basic types of photoreceptors: rods, and cones. Rods are sensitive to bluegreen light with peak sensitivity at a wavelength of 498 nm, and are used for vision under dark or dim conditions. There are three types of cones that give us our basic color vision: L-cones (red) with a peak sensitivity of 564 nm, M-cones (green) with a peak sensitivity of 533 nm, and S-cones (blue) with a peak sensitivity of 437 nm.

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Cones are highly concentrated in a region near the center of the retina called the fovea region. The maximum concentration of cones is roughly 180,000 per square mm in the fovea region and this density decreases rapidly outside of the fovea to a value of less than 5,000 per square mm. Note the blind spot caused by the optic nerve which is void of any photoreceptors.

The standard definition of normal visual acuity (20/20 vision) is the ability to resolve a spatial pattern separated by a visual angle of one minute of arc. Since one degree contains sixty minutes, a visual angle of one minute of arc is 1/60 of a degree.

- http://www.yorku.ca/eye/thejoy.htm What 20/20 or 6/6 means?

Do you know what 20/20 or 6/6 means? If not, read on. Simply put, 20/20 means that you are able to see on an eye chart at 20 feet that which a person with normal visual acuity can see. If you require glasses because your optometrist says you have 20/60 vision, that means you are able to discriminate characters on an eye chart at 20 feet that a person with normal acuity can see at a distance of 60 feet. 6/6 means the same thing only in meters.

A. Checkerboard- the observer has to tell which checkerboard is different.

B. Landholt C- the observer has to identify the location of the gap, e.g.. top, left, right or bottom.

C. Grating- the observer has to indicate whether the grating is vertical or horizontal.

D. Snellen letters- the observer has to identify the letter. This is probably the best known test. With the letter shown, for example, if a person can not resolve the gap in the letter it could easily be confused for the letter P.

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e-Paper & e-Book http://www.yorku.ca/eye/va-test.htm

Before reference is made to normal visual acuity. What does that mean? The standard definition of normal visual acuity is the ability to resolve a spatial pattern separated by a visual angle of one minute of arc.

Consider a circle which contains 360 degrees. One degree contains 60 minutes. Therefore, a visual angle of one minute of arc is 1/60 of a degree. The visual angle subtended by a spatial patterned is easily measured

- http://en.wikipedia.org/wiki/Minute_of_arc A minute of arc, arcminute, or MOA is a unit of angular measurement, equal to one sixtieth (1/60) of one degree. Since one degree is defined as one three hundred sixtieth (1/360) of a circle, 1 minute of arc is 1/21600 of the amount of arc in a closed circle.

Symbols, abbreviations and subdivisions The standard symbol for marking the arcminute is the prime (′) (U+2032), though a single quote (') (U+0027) is commonly used where only ASCII characters are permitted. One arcminute is thus written 1′. It is also abbreviated as arcmin or amin or, less commonly, the prime with a circumflex over it.

The subdivision of the minute of arc is the second of arc, or arcsecond. There are 60 arcseconds in an arcminute. Therefore, the arcsecond is 1/1296000 of a circle, or (π/648000) radians, which is approximately 1/206265 radian. The symbol for the arcsecond is the double prime (″) (U+2033). To express even smaller angles, standard SI prefixes can be employed; in particular, the milliarcsecond, abbreviated mas, is sometimes used in astronomy.

The sexagesimal system of angular measurement unit degree arcminute arcsecond milliarcsecond

value 1/360 circle 1/60 degree 1/60 arcminute 1/1000 arcsecond

symbol ° ′ (prime) ″ (double prime)

abbreviations deg arcmin, amin, , MOA arcsec mas

in radians (approx.)

17.4532925 mrad 290.8882087 µrad 4.8481368 µrad 4.8481368 nrad

□□□□□ - http://www.visionparaguay.org.uk/vp_websitenew_000002.htm Normal vision is 6/6 (20/20)

The first number "6" is the distance at which you read the chart (6 metres). The second number is the distance at which you should be able to read the letter.

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e-Paper & e-Books So a vision of 6/12 means that reading the chart at 6 metres you can only read the line you should be able to read at 12 metres.

If you convert metres to feet (6 metres = 20 feet) we get the American system

- http://www.squarecirclez.com/blog/what-does-2020-vision-mean/5062 What do these eye acuity fractions mean?

An eye chart consists of letters of varying sizes. (Optometrists use a symbol chart if the patient is likely to be illiterate.)

On the chart shown, the height of the 8th line (starting with “D”) is scaled so it is around 1.75 mm. From a distance of 20 feet (6 m), the height of the letters subtends an angle of 1 arc minute.

The angle “1 arc minute”, means 1/60 of one degree. (In turn, 1/60 of an arc minute is one arc second. We get these meaures from the Babylonian base-60 number system). To give an idea what this means, when we look at the full moon from the Earth, it subtends an angle of around 31 minutes, or just over half of one degree.

Someone with “normal” 20/20 vision will be able to read the 8th line at a distance of 20 feet.

In the fraction 20/20, the numerator (the first number) is the distance in feet between the subject and the eye chart. The denominator (the second number) is the distance from which a normal person can read the 8th line (and this gives a visual angle of 1 arc minute).

20/40 vision is half the acuity of 20/20. This means the patient can only see clearly at 20 feet what normal people can see at 40 feet. So a patient with 20/40 vision can see clearly only down to about the 6th or 7th line of the chart (text which is 3.5 mm high). This is the legal limit for driving in the United States.

On the other hand, 20/10 vision is twice normal acuity, and this would imply the patient can read down to the lowest line on the chart.

□□□□□ - http://www.exo.net/~pauld/workshops/zoom/resolution.htm Scientific Explorations with Paul Doherty © 2007 8 November 2007

Resolution Consider two identical black bars separated from each other by their width.

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e-Paper & e-Book What is the angular width of the central white bar that allows a human eye to see that there are 2 separate black bars?

We use the angular width because whether the eye can see two bars or not depends not only on the distance between the bars, “s”, but also the distance to the bars from the eye, “D”

The white space between two black bars has width s and is located a distance D from an eye.

The angle in radians, A, subtended by the distance s at a distance D is approximately A = s/D for small values of s/D For example a 1 cm white bar 1 meter away subtends an angle of A = 1/100 = 0.01 radians.

Now, there are 2pi radians in a complete circle and 360 degrees so 360 degrees/2pi radians = 57.2 degrees per radian.

Thus, an angle of 0.01 radian is about 0.57 degrees.

(Optional, for larger values of s/D, A = 2 arctan(s/2D) so stick to small values!)

So What?

A human eye with 20/20 vision can see bars separated by an angle of 1/60 degree also known as one arcminute or 0.3 milliradian, 3 x 10^-4 radian.

An eye vieweing black bars. The images fall on cones on the retina. The lines cross at the center of the "lens" that is composed of the cornea and lens of the eye.

The light receptors known as cones in the center of the retina, on the fovea, have a width of 2.5 micrometers, 2.5 x 10^-6 m. The eye is about 2.5 cm long. From the front of the eye, one cone subtends 0.1 milliradian. A = s/D = 2.5 x 10^-6/2.5 x 10^-2 = 0.0001 radian.

The resolution of the eye, 0.3 milliradian, is slightly worse than would be expected if the eye were a perfect detector, 0.1 milliradian, where if the black bar fell on one cone, then the white bar on the adjacent cone, and the black bar on the very next cone they eye should be able to resolve the gap between the bars. However, an average person needs a gap that is three times larger than this to resolve the separation of the bars.

Some people however can see at 20/10 so they approach the theoretical limit for human perception.

When the back bars subtend an angle smaller that the resolution of the eye they are seen as an undivided gray square.

□□□□□ - http://vresources.org/HMD_rezanalysis.html Let us first define what an arc minute per pixel is. One arc minute represent 1/60 of a degree. So the angle defined by the left and right extent of a picture element (pixel) define a value in arc minute per pixel. The figure illustrate this definition.

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For the human, the maximum angular resolution of the eye is around 1 arc minute for the smallest point that can be seen (it can be as little as 1/3 minutes of arc per pixel in some specific circumstances). This high visual acuity region is localized in the fovea on the retina, where there is the highest density of cones. These cones are mostly responsible for the central color vision.

□□□□□ - http://webvision.med.utah.edu/KallSpatial.html#introduction Visual Acuity Visual acuity is the spatial resolving capacity of the visual system. This may be thought of as the ability of the eye to see fine detail. There are various ways to measure and specify visual acuity, depending on the type of acuity task used. Visual acuity is limited by diffraction, aberrations and photoreceptor density in the eye (Smith and Atchison, 1997). Apart from these limitations, a number of factors also affect visual acuity such as refractive error, illumination, contrast and the location of the retina being stimulated.

Types of acuity tasks.

Target detection requires only the perception of the presence or absence of an aspect of the stimuli, not the discrimination of target detail

The task of detection involves stating whether the spot or line is present. (a) Bright test object on a dark background. (b) Dark test object on a bright background.

The Landolt C and the Illiterate E are other forms of detection used in visual acuity measurement in the clinic. The task required here is to detect the location of the gap.

(a) Landolt C. (b) Illiterate E.

Target recognition tasks, which are most commonly used in clinical visual acuity measurements, require the recognition or naming of a target, such as with Snellen letters. Test objects used here are large enough that detection is not a limiting factor (figure below), but careful letter choice and chart design are required to ensure that letter recognition tasks are uniform for different letter sizes and chart working distances (Bailey and Lovie, 1976).

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The task of recognition. Naming the test objects, in this case, letters of the alphabet (Snellen).

Snellen letters are constructed so that the size of the critical detail (stroke width and gap width) subtends 1/5th of the overall height. To specify a person's visual acuity in terms of Snellen notation, a determination is made of the smallest line of letters of the chart that he/she can correctly identify. Visual acuity (VA) in Snellen notation is given by the relation: VA = D'/D where D' is the standard viewing distance (usually 6 metres) and D is the distance at which each letter of this line subtends 5 minutes of arc (each stroke of the letter subtending 1 minute).

For a visual acuity of 6/6, the whole letter subtends an angle of 5 minutes of arc at the eye, and is viewed at 6 metres (20 feet).

The reciprocal of the Snellen Notation equals the angle (in minutes of arc) which the strokes of the letter subtend at the person's eye. This angle is also used to specify visual acuity. It is called the minimum angle of resolution (MAR) and can also be given in log10 form, abbreviated as logMAR.

For a visual acuity of 6/6 (20/20), one of the strokes of the letter subtends one minute of arc at the eye. Therefore, the minimum angle of resolution (MAR) is one minute of arc and the logMAR is 0.

Target resolution thresholds are usually expressed as the smallest angular size at which subjects can discriminate the separation between critical elements of a stimulus pattern such as a pair of dots, a grating or a checkerboard.

The task of resolution. (a) Double dot target. (b) Acuity grating. (c) Checkerboard.

Target localisation involves discriminating differences in the spatial position of segments of a test object, such as a break or discontinuity in contour. Visual acuity measured in this way is called Vernier acuity (a type of hyperacuity) and the discontinuity is specified in terms of its angular size.

The task of localisation. The above is an example of Vernier acuity.

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□□□□□ - http://www.madsci.org/posts/archives/1997-05/864446241.Ph.r.html Adrian Popa, Staff Optical/Microwave Physics - May 1997

FUNDAMENTAL LIMIT OF OPTICAL RESOLUTION The fundamental limit of optical resolution is determined by the wavelength of light that is used to illuminate the object. We cannot see objects or detail that is smaller than a light wavelength. Human vision spans from 720 nanometers (2.83 microinches) in the red wavelengths of light to 400 nanometers (1.57 microinches) in the blue violet wavelengths. Scientists typically use 560 nanometers (2.2 microinches) as an average value for white light containg all colors of the rainbow. (NOTE: a microinch = one millionth of an inch, a nanometer = one billionth of a meter).

We measure the resolution of an optical system, including human eyes, by the angular difference between two points of light that we can just resolve. At angles less than the resolution angle the points of light appear to be one bigger or brighter point. Scientists call these points of light POINT SOURCES and they can be double stars many millions of miles away or man made point sources in the laboratory. A number of double stars with different angular separation have been cataloged and amateur astronomers often use them to measure the resolution of their telescopes. An excellent point source of light which can be easily moved around the laboratory is light emitted from the end of an optical fiber. Special optical fibers called SINGLE MODE FIBERS have light guiding glass cores that are only one light wavelength in diameter making them excellent point sources of light at the fundamental limit of resolution.

HUMAN EYE RESOLUTION As a small object is moved closer to a human eye it appears larger with more detail because it is filling more of the light sensors in the eyes retina. The human eye has maximum resolution when an object is viewed as close to the eye as possible before it goes out of focus. This point is called the NEAR POINT or the POINT OF MOST DISTINCT VISION. This point is about 25 centimeters (10inches) from the typical unaided human eye and the angular resolution of the eye at this point is about 1/60 degree (.0167 degree). This is equivalent to being able to resolve two fine human hairs spaced one hair width apart when placed at the point of most distinct vision . NOTE: a fine human hair is about 73 micrometers (29 microinches) in diameter. A fine hair is also about 130 wavelengths of light in diameter, so human vision at it's best has an angular resolution 130 times less than the fundamental optical limit of resolution. This is why we use telescopes and microscopes to improve our ability to see more detail in objects located at longer and shorter distances from the eye's near point and also improve our ability to resolve images at the near point. Also, the best optical instruments place their images at the eye's near point so that we can observe the greatest detail in these telescopic or microscopic images which are usually used to improve our eye's resolution through the process of magnification. There is a beautifully illustrated web book on human visual perception located at: http://www.yorku.ca/eye/thejoy.htm MadSci Network © 1997, Washington University Medical School

□□□□□ - http://www.clarkvision.com/articles/eye-resolution.html Notes on the Resolution and Other Details of the Human Eye In modern studies, like Curcio et al. (1990), acuity is measured in cycles per degree. Curcio et al. derived 77 cycles per degree, or 0.78 arc-minute/cycle. Again, you need an minimum of 2 pixels to define a cycle, so the pixel spacing is 0.78/2 = 0.39 arc-minute, close to the above numbers.

Visual Acuity and Resolving Detail on Prints How many pixels are needed to match the resolution of the human eye? Each pixel must appear no larger than 0.3 arc-minute. Consider a 20 x 13.3-inch print viewed at 20 inches. The Print subtends an angle of 53 x 35.3 degrees, thus requiring 53*60/.3 = 10600 x 35*60/.3 = 7000 pixels, for a total of ~74 megapixels to show detail at the limits of human visual acuity.

The 10600 pixels over 20 inches corresponds to 530 pixels per inch, which would indeed appear very sharp.

Note in a recent printer test I showed a 600 ppi print had more detail than a 300 ppi print on an HP1220C printer (1200x2400 print dots). I've conducted some blind tests where a viewer had to sort 4 photos (150, 300, 600 and 600 ppi prints). The two 600 ppi were printed at 1200x1200 and 1200x2400 dpi. So far all have gotten the correct order of highest to lowest ppi (includes people up to age 50).

See: http://www.clarkvision.com/imagedetail/printer-ppi

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Summing up human eye resolution The resolution depends on distance of reading: at 25 cm is adequate a 300dpi resolution A resolution less than 150 dpi is insufficient to quality prints.

An object is visually well-defined if it is observed at a maximum distance from: Distance to the support Resolution from which a human eye no longer sees dots 6,3 cm (2.3 in) 1200 dpi 12,7 cm (5 in) 600 dpi 20 cm (7.8 in) 380 dpi 25,3 cm (9 in) 300 dpi 30 cm (11.8in) 253 dpi – 286dpi - http://fr.wikipedia.org/wiki/R%C3%A9solution_num%C3%A9rique - http://www.astrosurf.com/luxorion/rapport-restitution-images-ordinateur.htm

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iPhone Retina display - http://www.kybervision.com/Blog/files/AppleRetinaDisplay.html Apple "Retina Display" in iPhone 4: a Vision Scientist Perspective June 06 2010 William H.A. Beaudot, PhD, Vision Scientist at KyberVision

What are Apple's claims about its "Retina Display" and are they false marketing?

Apple's official marketing claim is that "the Retina display’s pixel density is so high, your eye is unable to distinguish individual pixels". In his keynote, Steve Jobs elaborated a bit more by referring to a magic number for the pixel density (around 300 pixels per inch or ppi) of a display hold about 10 to 12 inches away as the limit of the human retina to differentiate the pixels. Though Steve Jobs does not say explicitly, this magic number is in fact closely related to the standard visual acuity (20/20): a visual acuity of 20/20 means that a normal human eye can discriminate two points separated by 1 arc minute (1/60 deg) which is equivalent to an angular resolution of 30 cycles per degree (cpd). Seen from a distance of 1 foot (12 inches or 30 cm), a visual angle of 1 arc minute corresponds to a dot size of about 89 micrometers, that is a pixel density of 286.5 ppi (11.3 pixels per mm).

So, Apple "Retina Display" with its 326 ppi has a pixel density 14% better than the 286 ppi required to deliver a resolution compatible with a 20/20 visual acuity from a distance of 1 foot. More specifically, Apple "Retina Display" can deliver a visual resolution equivalent to a 20/17 acuity at a distance of 12", or for the sake of clarity to a 20/20 acuity at 10". In these conditions, refuting Apple's marketing claim would be unfair and misleading. In my opinion, Apple's claim is not just marketing, it is actually quite accurate based on a 20/20 visual acuity. However it is also important to note that the maximum acuity of a healthy human eye is approximately 20/16 to 20/12, so it would be inaccurate to refer to 20/20 visual acuity as "perfect" vision (despite the popular belief). The significance of the 20/20 standard can be best thought of as the lower limit of the normal visual acuity.

□□□□□ - http://www.edibleapple.com/scientists-bicker-about-apples-retina-display-claims-but-who-the-hell-really-cares/ Jun 18, 2010

One of the key points Steve Jobs stressed during his WWDC Keynote was the iPhone 4’s impressive new retina display which sports a resolution of 960×640 and a ppi of 326. But why the name Retina Display, you ask? Well, Jobs stated that the human eye can only differentiate pixels up to 300 ppi, thereby making the iPhone 4’s high-res display more powerful, so to speak, than what the human eye can detect.

While Apple’s new display certainly sets a new standard when it comes to quality, some are curiously taking issue with Apple’s claim about the quality of the iPhone 4 display, along with Apple’s retina claims.

First up, Samsung immediately dismissed Apple’s efforts at quadrupling the iPhone’s resolution, opining that doing so only improves clarity by a scant 3-5%. Moreover, a Samsung spokesman said that increasing the resolution as Apple did could potentially battery drain by as much as 30%. Their take away? Well, whatdya know, they were busy touting AMOLED screens which they argue are better because they don’t need a blacklight while noting that they “make up for any resolution loss in other ways, such as higher contrast with true black, more accurate colors and no limits on viewing angles.”

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e-Paper & e-Book “Structurally, [Apple's] IPS LCD technology cannot catch up with AMOLED display technology,” a Samsung representative told the Korean Herald.

But as for the Retina Display itself, Raymond Soneira of DisplayMate Technologies got the ball rolling last Wednesday when he challenged Apple’s claim that the iPhone 4 display was so dense that it outweighed the human eye’s ability to differentiate between pixels.

Soneira wrote to PC Mag: The resolution of the retina is in angular measure - it’s 50 Cycles Per Degree. A cycle is a line pair, which is two pixels, so the angular resolution of the eye is 0.6 arc minutes per pixel.

So, if you hold an iPhone at the typical 12 inches from your eyes that works out to 477 pixels per inch. At 8 inches it’s 716 ppi. You have to hold it out 18 inches before it falls to 318 ppi.

So the iPhone has significantly lower resolution than the retina. It actually needs a resolution significantly higher than the retina in order to deliver an image that appears perfect to the retina.

Yeah, we don’t get it either.

But Soneira went on to explain to Wired that while the iPhone display is close to being perfect, “Steve pushed it a little too far.” Soneira went on to say that Jobs’ assertions were outlandish and reeked of false marketing.

Soneira, who possesses a Ph.D. in theoretical physics from Princeton and has been studying displays for 20 years, said it was inaccurate to measure the resolution of the eye in terms of pixels, because the eye actually has an angular resolution of 50 cycles per degree. Therefore, if we were to compare the resolution limit of the eye with pixels on a screen, we must convert angular resolution to linear resolution. After conversions are made, a more accurate “retina display” would have a pixel resolution of 477 pixels per inch at 12 inches, Soneira calculated.

Not to be outdone, Jim Darlymple of The Loop contacted a vision scientist last week to get his take on the Retina Display “controversy”.

This is what PH.D William H.A Beaudot, a vision scientist who formerly conducted research at McGill University in Montreal and founded KyberVision had to say.

In my opinion, Apple’s claim is not just marketing, it is actually quite accurate based on a 20/20 visual acuityA visual acuity of 20/20 means that a normal human eye can discriminate two points separated by 1 arc minute (1/60 deg). A visual angle of 1 arc minute seen from a distance of 1 foot corresponds to a dot size of about 89 micrometers or a pixel density of 286.5 dpi. Since the “Retina” display has a pixel density of 326 dpi (14% better than what we would expect from a 20/20 visual acuity at 1 ft), it would seem unfair and misleading to refute Apple’s marketing claim on this basis.

Since this display is able to provide a visual input to the retina with a spatial frequency up to 50 cycles per degree when viewed from a distance of 18-inches, it almost matches the retina resolution according to the Nyquist-Shannon sampling theorem,” said Beaudot. “As such, Apple new display device can be called without dispute a Retina Display. Could it get better? Sure, but so far this is the closest thing ever done in display technology for the consumer market that matches the human retina resolution.

And finally, Phil Plait, who, you know, “spent a few years calibrating a camera on board Hubble” strongly disagrees with Wired’s headline exlcaiming that Apple’s Retina Display is false marketing, while “mildly disagreeing” with Soneira’s claims.

Jobs claims the iPhone held at 12 inches from your face has pixels too small to be resolved by your eye. Soneira, the display expert quoted in the magazine articles, disputes that. He uses the 0.6 arcmin resolution for the human eye (so we use the scale factor = 5730). Let’s use that and run the numbers.

Something 12 inches away means your eye can resolve dots that are bigger than 12 inches / 5730 = 0.0021 inches So if the pixels on the iPhone are smaller than 0.0021 inches in size, then Jobs is right. Your eye won’t resolve them. If the pixels are bigger, Soneira is right, and your eye can resolve them.

The actual iPhone 4 has 326 pixels per inch (the display is 960 pixels high, and about 2.9 inches in length). You have to flip that to get the size of the pixel in inches: 1 / 326 = 0.0031 inches

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e-Paper & e-Books Uh oh! Things look bad for Jobs. The iPhone pixels are too big! At one foot away, your eye can resolve the pixels, and Jobs must be lying!

Or is he? Remember, Soneira used the 0.6 arcmin resolution of the eye, but that’s for perfect eyesight.Most people don’t have perfect eyesight. I sure don’t. A better number for a typical person is more like 1 arcmin resolution, not 0.6. In fact, Wikipedia’s lists 20/20 vision as being 1 arcmin, so there you go.

If I use 1 arcminute instead, the scale factor is smaller, about 3438. So let’s convert that to inches to see how small a pixel the human eye can resolve at a distance of one foot: 12 inches / 3438 = 0.0035 inches This means that to a more average eye, pixels smaller than this are unresolved. Since the iPhone’s pixels are 0.0031 inches on a side, it works! Jobs is actually correct. at 12 inches (30.48 cm) [Note: in the articles about all this, they used units of pixels per inch, whereas I've used the size of the pixels themselves. You can flip all these numbers to convert. The iPhone4 has a resolution of 326 ppi (pixels per inch). Soleira says the eye can resolve 1 / 0.0021 = 477 ppi. However, normal vision can see at 1 / 0.0035 = 286 ppi. So the density of pixels in the iPhone 4 is safely higher than can be resolved by the normal eye, but lower than what can be resolved by someone with perfect vision.]

3) So what does all this mean?

Let me make this clear: if you have perfect eyesight, then at one foot away the iPhone 4’s pixels are resolved. The picture will look pixellated. If you have average eyesight, the picture will look just fine.

So in a sense, both Jobs and Soneira are correct. At the very worst, you could claim Jobs exaggerated; his claim is not true if you have perfect vision. But for a lot of people, I would even say most people, you’ll never tell the difference. And if you hold the phone a few inches farther away it’ll look better.

□□□□□ - http://prometheus.med.utah.edu/~bwjones/2010/06/apple-retina-display/ Apple Retina Display Copyright © 2010 Bryan William Jones Scientist, Photographer June 24, 2010

One of the many compelling features of the new phone is the Retina Display. When Steve Jobs first invoked this term at the WWDC, my eyebrows were raised. Being a retinal scientist, I was immediately skeptical of just what he meant by “retinal display”. My mind immediately raced and I wondered if it might have been some of the interesting technology I got to see on my last visit to one of Apple’s technology development labs. I will not say anything about that visit, but this Retina Display, a super high resolution display was new technology that I had not seen before. Essentially it is an LED backlit LCD display with a *326* pixel per inch (960×640) display (John Gruber of Daring Fireball called this resolution display back in March) where each pixel measures a scant 78µm.

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e-Paper & e-Book After discussion with some folks, including an LCD engineer, they have pointed out that pixels are measured from center to center rather than edge to edge, so I have changed the scale bars to reflect new measurements with a micrometer. Additionally, others have emailed me noting that if the black space surrounding the pixels is taken into account, the pixels are in fact, square. So, the measurement of 78µm for the iPhone 4 is in fact 78µm from center to center of every pixel. Also, Ron Uebershaer sent in screenshots I’ve included at the bottom of this post that he made in MATLAB which conceptually demonstrate that the pixels are in fact square.

I am including images below of the iPhone 1G, the iPhone 3G, the iPhone 4G and the iPad to show some perspective on pixel sizes. The scale bar and my measurements are approximate as I was having a tough time in the lab tonight finding an appropriate calibration. Nevertheless, this should serve as a useful metric for examining the relative pixel sizes and for making the point of whether Apple’s Retina Display is marketing speak and hyperbole or if in fact, Apple’s claims have merit.

As you can see from this image, the iPhone 1G pixels (each composed of a red, green and blue sub-pixel) measure approximately 150µm x 500µm. Also note the blurryness of the image. This was optimally focused, but the LCD panel itself is behind a non-bonded pane of glass with touch sensor on it leading to some image degradation

As in the 1G iPhone, the iPhone 3G pixels are essentially the same size, though with a different contact location. Again, these pixels measure approximately 150µm x 150µm and this LCD display has the same blurring issues that are present in the iPhone 1G.

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This image of the iPhone 4G LCD is made at the same magnification as the 1G and 3G iPhones illustrating the substantially smaller pixel size in the iPhone 4G. These pixels are remarkably small and if you look carefully, appear to be composites themselves where each sub-pixel is composed of its own sub-pixels. I am not sure about this however and it may simply be an artifact of the construction. Also note that there is very little distortion in the pixel images as the iPhone 4G has a bonded glass cover, eliminating the space in between the LCD panel and the touch sensitive glass surface. iPhone1: ~150 x 150µm iPhone 3G: ~150µm x 150µm iPhone 4G: ~78µm x 78µm So… the claim from Steve was that this display had pixels that matched the resolution display of the human retina. Now, fan of Apple that I am, this struck me as perhaps a bit hyperbolic, so I figured I’d do some quick calculations to see where this claim fell. Apparently I am not the first Ph.D. to wonder as another came out calling the bluff of Mr. Jobs. Here is the deal though… While Dr. Soneira was partially correct with respect to the retina, Apple’s Retina Display adequately represents the resolution at which images fall upon our retina.

Essentially, this is a claim of visual acuity which is the ability of the visual system to resolve fine detail. There are an awful lot of considerations to take into account when making such a claim such as contrast, distance, the resolution of the display and some metric of pixel size which gives you an estimate of visual resolution on the retina. Claims of contrast ratios are notoriously flexible in a number of displays and will be influenced by a number of optical factors as well as the content being viewed and the black and color levels of the pixels as well as overall luminance. Apple claims an 800:1 pixel ratio and I’ll take them at their word on that and focus on the claims of resolution here.

A “normal” human eye is considered to have standard visual acuity or 20/20 vision. This means that a 20/20 eye can discriminate two lines or two pixels separated by 1 arcminute (1/60 degree).

The ability of an optical system to resolve fine detail requires minute spacing of optical detectors. In the retina, there detectors are the photoreceptors. Objects we look at at projected through the cornea and lens and imaged on the back of the eye on a plane that ideally lines up with the retinal photoreceptors.

Theoretically the limit of retinal resolution, say the ability to distinguish patterns of alternating black and white lines is approximately 120pixels/degree in an optimal, healthy eye with no optical abnormalities. Again, this corresponds to one minute of arc or 0.000291 radians (π/(60*180)). If one assumes that the nominal focal length of the eye is approximately 16mm, an optimal distance from the eye for viewing detail might be around 12 inches away from the eye which is reasonable to assume for someone viewing detail on their iPhone.

Dr. Soneira’s claims are based upon a retinal calculation of .5 arcminutes which to my reading of the literature is too low. According to a relatively recent, but authoritative study of photoreceptor density in the human retina (Curcio, C.A., K.R. Sloan, R.E. Kalina and A.E. Hendrickson 1990 Human photoreceptor topography. J. Comp. Neurol. 292:497-523.), peak cone density in the human averages 199,000 cones/mm2 with a range of 100,000 to 324,000. Dr. Curcio et. al. calculated 77 cycles/degree or .78 arcminutes/cycle of *retinal* resolution. However, this does not take into account the optics of the system which degrade image quality somewhat giving a commonly accepted resolution of 1 arcminute/cycle. So, if a normal human eye can discriminate two points separated by 1 arcminute/cycle at a distance of a foot, we should be able to discriminate two points 89 micrometers apart which would work out to about 287 pixels per inch. Since the iPhone 4G display is comfortably higher than that measure at 326 pixels per inch, I’d find Apple’s claims stand up to what the human eye can perceive.

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For reference, I am also including an image of the iPad LCD taken at the same magnification as the iPhone images above. As you can see, the pixel size is actually much larger and herringbone shaped which is not uncommon in high quality desktop displays like say, the Apple Cinema Display line.

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Compare display resolution - http://www.bit-101.com/blog/?m=201008 Aug 12 2010 Published by keith

Kindle and iPad Displays: Up close and personal.

The family had great fun playing with it tonight – looking at everyone’s skin and hair and dirty fingernails and bug bites, and paper and money and cloth and salt and sugar, etc. I could barely pry my daughter away from it. The software allows you to capture images and videos and even notate them with actual measurements, etc. based on the level of magnification.

While playing a bit more with it, I held it up to my computer screen and my Nexus One screen and could clearly see the pixels. Neat. Then I wondered what the Kindle’s screen looks like close up. Quite different! I then compared the Kindle’s screen at roughly 26x and 400x with the iPad’s screen at approximately the same resolution. Wow! First at about 26x.

iPad:

Kindle:

And now at about 400x for the Kindle and 375x for the iPad.

Kindle:

iPad:

The Kindle’s screen looks almost organic at high magnification.

Some additional photos at 26x and 400x, of print media.

First, newsprint, then a magazine, then a paperback book at 26x.

Newsprint:

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Magazine:

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Book:

And now the same three, in the same order, at 400x:

Newsprint:

Magazine:

Book:

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e-Paper & e-Books - http://www.bit-101.com/blog/?p=2750 Sep 03 2010 Published by keith

Yeah, this took a while, but I finally got around to sticking my new toy under the ‘scope. To be honest, the differences between the Kindle 2 and the new version are amazingly apparent the first time you turn the thing on. The contrast is supposedly 50% better, but my eyes say it is many times better. When I look at my Kindle 2 now, it does indeed look like “wet newspaper” as one of my dear commenters said in my last Kindle post.

Anyway, here are the closeups. In each case, the low res shots are approximately 25-26x and the high res ones are around 400x. I concentrated taking the same shots on the same images / words at the same size on both models. Note that all the images are links to full size images.

First, an image, a close up from one of the screensavers.

Kindle 2

Kindle 3

Pretty easy to see that the K3 is darker and crisper. But to the naked eye, I feel the effect is even more stunning. The screensaver photos themselves are rendered beautifully. I’d still like some new ones, but even as bored as I am with the, the first few times I saw them, I had to stare a while.

Now let’s zoom in on that eye, to 400x.

Kindle 2

Kindle 3

What you are seeing here are some gradient bands of gray values. What I notice here is that the various shades are noticeably different in the K3, and kind of muddled in the K2. Also, what seems to be happening in the K2 is that the microcapsules of E Ink are either spaced a bit further apart or somehow have some kind of dark border. They are very distinct from each other, whereas the K3 capsules seem closer together with less of a noticeable border. Thus, in the K2, the “white” areas still have so much dark border around them that the areas appear more gray than white, whereas in the K3, the white areas are more uniformly light. This is evident in several of the following pictures as well.

Here’s a closeup of one of the branches in the birds screensaver

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Kindle 2

Kindle 3

It also seems like in the K3, there is a bigger mix of smaller and larger capsules, resulting in what could be called a higher resolution.

Now, onto the important stuff, TEXT!

Kindle 2

Kindle 3

Mmm…. rich and dark.

Let’s zoom in on the rightmost vertical stroke of the letter “m”.

Kindle 2

Kindle 3

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e-Paper & e-Books Now we’re talking! Here you can really see just how dark the black is, as well as how much whiter the white is. And now the curve of the letter “e”.

Kindle 2

Kindle 3

Again, you can see the darkness and the uniformity of the blacks and whites. What’s interesting here is that the fuzziness of the K2 actually seems to result in some crude antialiasing, smoothing out the stairstep of the curve. I’m not sure what’s going on here. It’s obvious that the microcapsules themselves would be capable of a higher resolution. They are not what’s causing the “jaggies”. I guess it’s the underlying grid of chargeproducing elements that is giving you that pixelation. See the below image and link: http://en.wikipedia.org/wiki/E_Ink

Scheme of the E Ink technology.

Legend: 1 upper layer.

2 transparent electrode layer.

3 transparent micro-capsules.

4 positively charged white pigments.

5 negatively charged black pigments.

6 transparent oil.

7 electrode pixel layer.

8 bottom supporting layer.

9 light.

10 white.

11 black.

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http://www.noamberg.com/thesis/blowrg/?p=243

Plastic Logic's 100dpi display

e-ink iLiad’s reader: detail shot 160 dpi

150dpi panel

Sony psr-505 e-book reader, 166dpi

Extract from http://albrecht-schmidt.blogspot.com/2008/08/nicolas-villar-visiting.html

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- http://www.einkcorp.com/readable.html Electronic Paper Displays vs. LCD Displays

E Ink 25X

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LCD 25X

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e-Paper Technologies Reference Guide

Table modified by me from: E-Facts: A Master Thesis Presentation by Joe Evans & Sajjad Haider - Supervised by Lambert Spaanenburg (LHT) & Johan Marnfeldt (Lundinova)

http://www.eit.lth.se/index.php?id=345&no_cache=1&L=1&eauid=76 http://www.it.lth.se/dsk/literature/presE-Paper.pdf

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Useful definitions about electronic displays Active Matrix and Passive Matrix Active Matrix and Passive Matrix Compared - http://support.apple.com/kb/TA21582?viewlocale=en_US LCDs are non-emissive (no extra low frequency (ELF) or very low frequency (VLF) emissions); they do not create their own light, but reflect and block light. LCDs use a reflector, backlight, sidelight, or a combination of a reflector and back/sidelight to display an image.

The liquid crystal material is a liquid with rod-shaped molecules inside. The rod-shaped molecules can form a twisting helix, or spiral pattern and bend light that enters the display. When electric current is applied, the rods straighten out and no longer bend the light. The inside surfaces of the glass are treated and polished to induce the rod-shaped molecules in the liquid crystal material to line up with the polarizers.

The display uses two polarizers to line up the light and reduce glare. If the light is out of phase, it can not pass through the polarizer. By using two polarizers 90 degrees out of phase with each other, the light is blocked. The liquid crystal material bends the light 90 degrees so it will pass through the polarizer. When the LCD has power to it, it does not bend the light, hence it does not pass through the polarizer.

This type of display is called an active matrix, or Thin-Film Transistor (TFT), display. Passive matrix, or Film SuperTwist Nematic (FSTN), displays are similar to TFT displays, but the liquid crystal molecules in a SuperTwist Display bend or twists light much farther than in a standard TFT display. In fact, the molecules in a SuperTwist display can bend 270 degrees or more to transmit light. One difference you may notice between passive and active matrix screens is that active matrix has a much wider viewing range than passive matrix. In other words, you can see information displayed on the screen from a wider side angle on an active matrix display than on a passive matrix display.

Passive Matrix In a passive matrix, or FSTN, display a grid of electronic control wires or lines are placed on the front and back glass. A pixel is located at the junction of each row and column control lines. Passive matrix displays use one transistor to address each row and one to address each column of pixels. Pixels are turned on when both row and column lines are energized and off when both control lines are de-energized. This addressing scheme is called multiplexing.

The residual electrical current that travels down each control line can cause crosstalk at unselected pixels.

Crosstalk partially darkens pixels and lowers the display's overall contrast. This usually appears on a passive matrix PowerBook display as two dark boxes, parallel to each other on the display.

Active Matrix The active matrix, or Thin-Film Transistor (TFT) display is the latest technology used in Macintosh PowerBook computers. Rather than using multiplexing (row and column wires on the glass) techniques to address the matrix of crystals, the active matrix LCD includes a transistor fabricated along with each pixel.

You can think of the display as one large Integrated Circuit (IC), with the transistors acting as switches to turn on individual pixels. (An IC is a slice or chip of material on which is etched or imprinted a circuit comprised of electronic components and their interconnections.) Because of the transistors, pixels can be turned on and off at a very fast rate. The transistor at each pixel eliminates the crosstalk phenomenon, which lowers contrast on an FSTN display.

The TFT method eliminates the time dependency associated with multiplexed displays by directly addressing each pixel.

- http://www.sgi.com/products/legacy/1600sw_faq/ What is the difference between active matrix LCDs (AMLCD) and passive matrix LCDs? For an LCD to work, each pixel must be energized to either let light through or block light out. The difference between active matrix and passive matrix displays is the way in which the pixels are electrically addressed, or "energized." Passive matrix flat panel displays consist of a grid of horizontal and vertical wires. At the intersection of each grid is an LCD element that constitutes a single pixel. Active matrix flat panels are a higher quality and more expensive type of display in which transistors are built into each pixel within the screen. For example, the 1600x1024 screen size of the 1600SW requires over 14 million transistors, one for 32 Massimo Marrazzo - biodomotica.com

e-Paper & e-Book each red, green, and blue subpixel. Active matrix, sometimes also called TFT (thin film transistor) displays typically have higher resolution, higher contrast, and much faster pixel response rates than passive matrix LCDs. - http://encyclopedia2.thefreedictionary.com/active+matrix Active matrix The type of technology used in all LCD-based, flat panel color displays including TVs and desktop and laptop screens. It produces a brighter and sharper display with a broader viewing angle than passive matrix LCD screens, which are mostly monochrome. Active matrix technology uses a thin film transistor at each pixel and is often designated as a "TFT screen."

- http://www.webopedia.com/TERM/A/active_matrix_display.html Active matrix display Tweet A type of flat-panel display in which the screen is refreshed more frequently than in conventional passive-matrix displays. The most common type of active-matrix display is based on a technology known as TFT (thin film transistor). The two terms, active matrix and TFT, are often used interchangeably. http://encyclopedia2.thefreedictionary.com/Passive+matrix+addressing Passive matrix A common monochrome LCD technology used in small electronic devices and appliances, toys and home medical products. Passive matrix displays (DSTN, CSTN, etc.) are not quite as sharp as active matrix (TFT) displays, but they have improved dramatically over the years. Looking head on into a passive matrix screen is not all that different than an active matrix (TFT) screen, except that passive matrix is used for monochrome, and active matrix is used for color displays. However, the viewing angle is less; a person looking from the side sees a dimmer image with passive matrix -

http://www.webopedia.com/TERM/P/passive_matrix_display.html Passive-matrix display A common type of flat-panel display consisting of a grid of horizontal and vertical wires. At the intersection of each grid is an LCD element which constitutes a single pixel, either letting light through or blocking it. A higher quality and more expensive type of display, called an active-matrix display, uses a transistor to control each pixel.

In the mid-90s, it appeared that passive-matrix displays would eventually become extinct due to the higher quality of active-matrix displays. However, the high cost of producing active-matrix displays, and new technologies such as DSTN, CSTN and HPA that improve passive-matrix displays, have cause passivematrix displays to make a surprising comeback.

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Frontplane & Backplane http://blogs.telegraph.co.uk/shane_richmond/blog/2007/02/07/is_this_the_newspaper_of_the_future A display is made of a front plane and a back plane. The front plane gives the appearance towards the user, the back plane contains the electronics circuitry to manage the front plane. http://thefutureofthings.com/articles/1000/the-future-of-electronic-paper.html E-paper comprises two parts: The first is electronic ink, sometimes referred to as the frontplane, and the second is the electronics required to generate the pattern of text and images on the e-ink page, called the backplane.

http://www.geocities.com/CapeCanaveral/1999/epublishing.html

Active Matrix

Backplane

Bistable Displays http://sunlightlcd.blogspot.com/2007/11/flat-panel-display.html Bistable Displays can retain the displayed image without any power.

Energy is only needed to change the image. “This means that the image they hold requires no energy to maintain, but instead requires energy to change.

This results in a much more energy efficient display, but with a tendency towards slow refresh rates which are undesirable in an interactive display.�

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LCD - http://electronics.howstuffworks.com/lcd.htm

TFT-LCD

(TFT thin film transistors) — (LCD liquid crystal display)

The name "liquid crystal" sounds like a contradiction. We think of a crystal as a solid material like quartz, usually as hard as rock, and a liquid is obviously different. How could any material combine the two?

We learned in school that there are three common states of matter: solid, liquid or gaseous. Solids act the way they do because their molecules always maintain their orientation and stay in the same position with respect to one another. The molecules in liquids are just the opposite: They can change their orientation and move anywhere in the liquid. But there are some substances that can exist in an odd state that is sort of like a liquid and sort of like a solid. When they are in this state, their molecules tend to maintain their orientation, like the molecules in a solid, but also move around to different positions, like the molecules in a liquid. This means that liquid crystals are neither a solid nor a liquid. That's how they ended up with their seemingly contradictory name.

So, do liquid crystals act like solids or liquids or something else? It turns out that liquid crystals are closer to a liquid state than a solid. It takes a fair amount of heat to change a suitable substance from a solid into a liquid crystal, and it only takes a little more heat to turn that same liquid crystal into a real liquid. This explains why liquid crystals are very sensitive to temperature and why they are used to make thermometers and mood rings. It also explains why a laptop computer display may act funny in cold weather or during a hot day at the beach.

Nematic Phase Liquid Crystals Just as there are many varieties of solids and liquids, there is also a variety of liquid crystal substances.

Depending on the temperature and particular nature of a substance, liquid crystals can be in one of several distinct phases (see below). In this article, we will discuss liquid crystals in the nematic phase, the liquid crystals that make LCDs possible.

One feature of liquid crystals is that they're affected by electric current. A particular sort of nematic liquid crystal, called twisted nematics (TN), is naturally twisted. Applying an electric current to these liquid crystals will untwist them to varying degrees, depending on the current's voltage. LCDs use these liquid crystals because they react predictably to electric current in such a way as to control light passage.

Most liquid crystal molecules are rod-shaped and are broadly categorized as either thermotropic or lyotropic.

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Image courtesy Dr. Oleg Lavrentovich, Liquid Crystal Institute

Most liquid crystal molecules are rod-shaped and are broadly categorized as either thermotropic or lyotropic.

Thermotropic liquid crystals will react to changes in temperature or, in some cases, pressure. The reaction of lyotropic liquid crystals, which are used in the manufacture of soaps and detergents, depends on the type of solvent they are mixed with. Thermotropic liquid crystals are either isotropic or nematic. The key difference is that the molecules in isotropic liquid crystal substances are random in their arrangement, while nematics have a definite order or pattern.

The orientation of the molecules in the nematic phase is based on the director. The director can be anything from a magnetic field to a surface that has microscopic grooves in it. In the nematic phase, liquid crystals can be further classified by the way molecules orient themselves in respect to one another. Smectic, the most common arrangement, creates layers of molecules. There are many variations of the smectic phase, such as smectic C, in which the molecules in each layer tilt at an angle from the previous layer. Another common phase is cholesteric, also known as chiral nematic. In this phase, the molecules twist slightly from one layer to the next, resulting in a spiral formation.

To create an LCD, you take two pieces of polarized glass. A special polymer that creates microscopic grooves in the surface is rubbed on the side of the glass that does not have the polarizing film on it. The grooves must be in the same direction as the polarizing film. You then add a coating of nematic liquid crystals to one of the filters. The grooves will cause the first layer of molecules to align with the filter's orientation. Then add the second piece of glass with the polarizing film at a right angle to the first piece.

Each successive layer of TN molecules will gradually twist until the uppermost layer is at a 90-degree angle to the bottom, matching the polarized glass filters.

As light strikes the first filter, it is polarized. The molecules in each layer then guide the light they receive to the next layer. As the light passes through the liquid crystal layers, the molecules also change the light's plane of vibration to match their own angle. When the light reaches the far side of the liquid crystal substance, it vibrates at the same angle as the final layer of molecules. If the final layer is matched up with the second polarized glass filter, then the light will pass through.

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If we apply an electric charge to liquid crystal molecules, they untwist. When they straighten out, they change the angle of the light passing through them so that it no longer matches the angle of the top polarizing filter. Consequently, no light can pass through that area of the LCD, which makes that area darker than the surrounding areas.

The LCD needed to do this job is very basic. It has a mirror (A) in back, which makes it reflective. Then, we add a piece of glass (B) with a polarizing film on the bottom side, and a common electrode plane (C) made of indium-tin oxide on top. A common electrode plane covers the entire area of the LCD. Above that is the layer of liquid crystal substance (D). Next comes another piece of glass (E) with an electrode in the shape of the rectangle on the bottom and, on top, another polarizing film (F), at a right angle to the first one.

The electrode is hooked up to a power source like a battery. When there is no current, light entering through the front of the LCD will simply hit the mirror and bounce right back out. But when the battery supplies current to the electrodes, the liquid crystals between the common-plane electrode and the electrode shaped like a rectangle untwist and block the light in that region from passing through. That makes the LCD show the rectangle as a black area.

Backlit vs. Reflective Note that our simple LCD required an external light source. Liquid crystal materials emit no light of their own. Small and inexpensive LCDs are often reflective, which means to display anything they must reflect light from external light sources. Look at an LCD watch: The numbers appear where small electrodes charge the liquid crystals and make the layers untwist so that light is not transmitting through the polarized film.

Passive and Active Matrix Passive-matrix LCDs use a simple grid to supply the charge to a particular pixel on the display. Creating the grid is quite a process! It starts with two glass layers called substrates. One substrate is given columns and the other is given rows made from a transparent conductive material. This is usually indium-tin oxide. The 36 Massimo Marrazzo - biodomotica.com

e-Paper & e-Book rows or columns are connected to integrated circuits that control when a charge is sent down a particular column or row. The liquid crystal material is sandwiched between the two glass substrates, and a polarizing film is added to the outer side of each substrate. To turn on a pixel, the integrated circuit sends a charge down the correct column of one substrate and a ground activated on the correct row of the other. The row and column intersect at the designated pixel, and that delivers the voltage to untwist the liquid crystals at that pixel.

The simplicity of the passive-matrix system is beautiful, but it has significant drawbacks, notably slow response time and imprecise voltage control. Response time refers to the LCD's ability to refresh the image displayed. The easiest way to observe slow response time in a passive-matrix LCD is to move the mouse pointer quickly from one side of the screen to the other. You will notice a series of "ghosts" following the pointer. Imprecise voltage control hinders the passive matrix's ability to influence only one pixel at a time.

When voltage is applied to untwist one pixel, the pixels around it also partially untwist, which makes images appear fuzzy and lacking in contrast.

Active-matrix LCDs depend on thin film transistors (TFT). Basically, TFTs are tiny switching transistors and capacitors. They are arranged in a matrix on a glass substrate. To address a particular pixel, the proper row is switched on, and then a charge is sent down the correct column. Since all of the other rows that the column intersects are turned off, only the capacitor at the designated pixel receives a charge. The capacitor is able to hold the charge until the next refresh cycle. And if we carefully control the amount of voltage supplied to a crystal, we can make it untwist only enough to allow some light through.

By doing this in very exact, very small increments, LCDs can create a gray scale. Most displays today offer 256 levels of brightness per pixel.

Color LCD An LCD that can show colors must have three subpixels with red, green and blue color filters to create each color pixel.

Through the careful control and variation of the voltage applied, the intensity of each subpixel can range over 256 shades. Combining the subpixels produces a possible palette of 16.8 million colors (256 shades of red x 256 shades of green x 256 shades of blue), as shown below. These color displays take an enormous number of transistors. For example, a typical laptop computer supports resolutions up to 1,024x768. If we multiply 1,024 columns by 768 rows by 3 subpixels, we get 2,359,296 transistors etched onto the glass! If there is a problem with any of these transistors, it creates a "bad pixel" on the display. Most active matrix displays have a few bad pixels scattered across the screen.

LCD color matrix at 60x magnification LCD technology is constantly evolving. LCDs today employ several variations of liquid crystal technology, including super twisted nematics (STN), dual scan twisted nematics (DSTN), ferroelectric liquid crystal (FLC) and surface stabilized ferroelectric liquid crystal (SSFLC).

Ferroelectric liquid crystals (FLCs) use liquid crystal substances that have chiral molecules in a smectic C type of arrangement because the spiral nature of these molecules allows the microsecond switching response time that make FLCs particularly suited to advanced displays. Surface-stabilized ferroelectric liquid crystals (SSFLCs) apply controlled pressure through the use of a glass plate, suppressing the spiral of the molecules to make the switching even more rapid.

□□□□□ Backlight.

Most computer Liquid Crystal Display (LCD) panels are lit with built-in fluorescent tubes above, beside and sometimes behind the LCD. A white diffusion panel behind the LCD redirects and scatters the light evenly to ensure a uniform display. This is known as a backlight.

A fluorescent light is most often a long straight glass tube that produces white light. Inside the glass tube there is a low-pressure mercury vapor. When ionized, mercury vapor emits ultraviolet light. Human eyes are Massimo Marrazzo - biodomotica.com 37

e-Paper & e-Books not sensitive to ultraviolet light (although human skin is). The inside of a fluorescent light is coated with phosphor. Phosphor is a substance that can accept energy in one form and emit the energy in the form of visible light. For example, energy from a high-speed electron in a TV tube is absorbed by the phosphors that make up the pixels. The light we see from a fluorescent tube is the light given off by the phosphor coating the inside of the tube. The phosphor fluoresces when energized, hence the name.

Compare the size of this fluorescent tube from a laptop computer to the pencil beside it and you see how tiny it is.

A typical laptop display uses a tiny Cold Cathode Fluorescent Lamp (CCFL) for the backlight. One of these small tubes is able to provide a bright white light source that can be diffused by the panel behind the LCD. In addition to providing ample light, CCFLs do not rise far above the ambient temperature. This makes them ideal for LCD panels since the light source is in close proximity to other components that could be ruined by excessive heat.

One amazing thing about these lamps is their incredible size. They are very thin and the board that drives the lamp is very small as well. However, it is not that hard to break them, which is why your display may go dark if you drop your laptop

□□□□□ - http://www.vertexlcd.com/technology.htm LCD (Liquid Crystal Display) Liquid Crystals are substances, which are not liquid or solid, that bend and refract light waves as they pass through them. With the addition of external electric charges,the property of light changes creating the various shades of color and shadow you see on the display.

Currently, there are four competing LCD technologies in the market using liquid crystals TN+Film, VA, IPS and FFS. Today, LCD screens are used in all aspects of our daily life.

Digital watches, cellular phones, televisions, and even outdoor advertisement boards remind us of how LCD has changed the way we live, and where it will take us tomorrow.

The Four LCD Technologies TN + Film is used for entry level and mid-range solutions Known for: simple process, high transmittance, fast response rate Improvements needed: viewing angle, color shift, contrast ratio Frequently used for notebook Not Desirable for LCD TVs VA is used for mid- to top-range solutions Known for: high transmittance, fast response rate Improvements needed: costs for compensation film, process complexity, color shift quality Not applicable for tablet PCs IPS is used for high-end solutions Known for: high color stability, simple process Improvements needed: transmittance (low), contrast ratio (low)

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e-Paper & e-Book FFS is used for high-end solutions Known for: high transmittance, wide viewing angle, authentic color

- http://en.wikipedia.org/wiki/Thin-film_transistor Thin-film transistor (TFT) A thin-film transistor (TFT) is a special kind of field-effect transistor made by depositing thin films of a semiconductor active layer as well as the dielectric layer and metallic contacts over a supporting substrate. A common substrate is glass, since the primary application of TFTs is in liquid crystal displays. This differs from the conventional transistor where the semiconductor material typically is the substrate, such as a silicon wafer.

Several types of TFT constructions.

1 - Glass plates 2/3 - Horizontal and vertical polarisers 4 - RGB colour mask 5/6 - Horizontal and vertical command lines 7 - Rugged polymer layer 8 - Spacers 9 - Thin film transistors 10 - Front electrode 11 - Rear electrodes

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e-Paper & e-Books - http://reference.findtarget.com/search/Liquid%20crystal%20display/ In colour LCDs each individual pixel is divided into three cells, or subpixels, which are coloured red, green, and blue, respectively, by additional filters (pigment filters, dye filters and metal oxide filters). Each subpixel can be controlled independently to yield thousands or millions of possible colours for each pixel. CRT monitors employ a similar 'subpixel' structures via phosphors, although the electron beam employed in CRTs do not hit exact subpixels. The figure at the left shows the twisted nematic (TN) type of LCD

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Bistable LCD - http://www.lumex.com/news/article/bi-stable_lcd_technology_uses_99_less_power_than_traditional_lcds/ Bi-Stable LCD Technology Uses 99% LESS Power Than Traditional LCDs July 2010

Lumex announces the global launch of their InfoVue Bi-Stable family of displays, a low-power LCD solution well-suited for a wide range of applications where display information is not changed more than a few times a day. For some applications, the Lumex InfoVue Bi-Stable LCD requires up to 99% less energy consumption than traditional LCD technologies.

A traditional LCD module requires 25-50mW of constant power to display even a static, unchanging image.

Lumex´s Bi-Stable LCDs can display the same information for over a year after power has been turned off with just a onetime 2-5second burst of 10mW of power. The new technology enables users to more easily update vital display information while also generating cost and manpower savings.

Compatible with a variety of LCD configurations, the bistable technology can replace standard LCD technology or printed displays where information changes with less frequency than is the case for traditional LCD applications.

- http://www.epapercentral.com/flexible-bistable-lcds-enter-epaper-arena.htm Flexible, Bistable LCDs enter e-Paper arena Jun 2009

While Liquid Crystal Displays offer excellent picture quality with brilliant color and video, they require a brushing process on the inside of a glass sandwich to lock the twisted molecules. These twisted molecules are necessary for bistable displays, which offer low voltage advantages. As such, it is not possible to use flexible substrates, which are becoming a requirement for foldable/bendable e-readers. Recently, Professor Vladimir Chigrinov at Hong Kong University of Science and Technology has developed an experimental LCD electronic paper, which he claims is lightweight, flexible, thin, robust, durable and potentially low cost.

Photo-Alignment Process

The process that researchers have developed is a roll-to-roll technology, which uses a new photo-alignable polymer-an azo-dye, which has an anchoring energy that can be adjusted by changing the UV exposure time. Using a photo-alignment process eliminates the brushing of the glass, which is needed to lock LCD molecules in their twisted state.

The layer is stabilized by heat polymerization after the azo-dye monomers are photo-aligned. Professor Chigrinov used 150ÂşC on a PES substrate. Lower cost PET may be possible later. The liquid crystal is then deposited on top.

According to researchers this arrangement is inherently low cost, likely to give much better colors than electrophoretic technology, be more robust and operate without need of a transistor active matrix backplane or ITO or alternative transparent electrodes with all their problems of cost and of cracking when bent.

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□□□□□

□□□□□ - http://www.fokus-technologies.de/technology_en.phtml TFT-LCD = thin film transistor liquid cristal display.

The screen uses liquid crystal to control the passage of light. The front glass is fitted with a colour filter, while the back glass has transistors fabricated on it. A light source, called the backlight unit, is located at the back of the panel. When voltage is applied to a transistor, the liquid crystal is bent, allowing light to pass through to form a pixel. The colour filter of the front glass gives the pixel its own colour. The combination of these pixels in different colours forms the image on the panel.

"Operating principle of a LCD pixel using twisted nematic ("thread-like") liquid crystal molecules (Courtesy of Merck KGaA, Darmstadt, Germany)" Image source: German Flat Panel Display Forum

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- http://www.optoiq.com/index/photonics-technologies-applications/lfw-display/lfw-article-display/218581/articles/laser-focusworld/volume-40/issue-12/technology-review-2004/technology-review-2004/illuminating-achievements.html

Image is everything Having long ago clinched the laptop-computer-display market, the active-matrix liquid-crystal display (AMLCD) is adding desktop computers and television to its conquests. Variations on the technology continue to be developed. Nemoptic (Paris, France) is developing a bistable LCD with multiple gray-level control (bistable displays can be turned off and still retain their image—a feature that saves power even when they are on). Bistablility is achieved by controlling the position of a defect line inside each pixel by liquid-crystal backflow—the so-called “curtain” effect. Thirty-two gray-scale levels are possible—when combined with standard LCD color filters, a full-color (32K) display results. The company’s most recent version is a transmissive color display.

A bistable transmissive LCD produces full-color images while using less power than conventional LCDs.

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Transparent TFT-LCD - http://techpatio.com/2009/mobiles/sony-ericsson/sony-ericsson-xperia-pureness-600-euro-november-uk-price

by Klaus on September 21, 2009

The Xperia Pureness mobile phone from Sony Ericsson is the first phone with a transparent main screen.

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http://www.sonyericsson.com/cws/products/mobilephones/overview/xperiapureness?cc=global&lc=en

Screen Transparent scratch-resistant monochrome 1.8" TFT

- http://www.youtube.com/watch?v=dIpSMTxuyxk&feature=player_embedded

VIDEO - Sony Ericsson Xperia Pureness - unboxing and demo

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IPS-LCD - http://www.pctechguide.com/43FlatPanels_In-Plane_Switching.htm IPS-LCD (In-Plane Switching) In-Plane Switching (IPS) was one of the first refinements to produce significant gains in the light-transmissive characteristics of TFT panels. Jointly developed by Hosiden and NEC, it is a technology that addresses the two main issues of a standard twisted nematic (TN) TFT display: colour and viewing angle.

With IPS, the crystals are aligned horizontally to the screen rather than vertically, and the electrical field is applied between each end of the crystal molecules - termed a "lateral electric field." In this way, the crystals are kept parallel to the the electrode pair, and thus the glass substrate of the screen. The liquid crystal molecules are not anchored to the lower glass substrate, so move more freely into the desired alignment.

Comparing TN and IPS Light Flow Through LCD Monitors In a TN TFT display when one end of the liquid crystal is anchored to the lower glass substrate and a voltage is applied, the crystal compounds untwist, changing the angle of polarisation of the transmitted light. A downside of basic TN technology is that the alignment of molecules of liquid crystal alters the further away they are from the anchored electrode, turning at right angles to the substrates. This impairs the flow of light causing diminishing contrast, brightness and colour definition at wider angles to the screen.

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e-Paper & e-Book - http://www.pcworld.com/article/188141/ipad_ips_screen_technology_explained.html iPad: IPS Screen Technology Explained

By Chris Brandrick, PCWorld

In-Plane Switching (IPS) is an LCD technology first introduced in 1996 by Hitachi. It was initially developed to correct the poor viewing angles and color problems that LCDs had at the time.

Due to initial high-costs, IPS adoption was low at first, and mainly found only in high-end monitors, aimed primiarliy at the professional sector. Of course, over time, IPS was improved and refined, and as is the case with most new technologies, costs eventually came down to an acceptable level for mass-production. For example, Apple's newest iMacs use IPS displays.

The IPS display used int he iPad is a 9.7-inch 1024-by-768 resolution LED-backlit LCD screen. IPS gives the iPad an impressive wide viewing-angle of up to 178 degrees. Other LCD technologies tend to have narrower viewing angles, especially in the vertical direction.

Ensuring that the device can be held in a variety of ways without major viewing angle issues was clearly of great importance to Apple, especially considering that you'll rotate the iPad depending on what you're viewing, and Apple positions the iPad as a casual use 'living-room' device, perfect for consuming an assortment of multimedia.

Typical casual-use devices, namely netbooks, use a twisted nematic (TN) display technology. TN although cheaper, offers inferior color reproduction (only 6-bit color, while IPS supports richer 8-bit color), and lower viewing angles, so Apple's use of a higher quality display techology (IPS) for such a casual device is welcomed.

You can find out more about how IPS technology works at PCTechGuide, and for a full run-down of iPad specs, see Jason Cross' story on the topic.

- http://www.oled-display.net/hydis-deliver-s-ips-lcd-panels-for-the-galaxy-tab-%20amoled-version-scheduled-for-mid-2011

Hydis deliver S-IPS LCD Panels for the Galaxy-Tab AMOLED version scheduled for mid 2011 The display from the Samsung Galaxy Tab is a S-IPS LCD Panel from Hydis. This technology is the same like LG-Displays IPS display for the Apple products.Digitimes thinks that Hydis use the FFS technology.

Currently, there are four competing LCD technologies in the market using liquid crystals TN+Film, VA, IPS, and FFS.

LCD TFT Panel Structure Comparison

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S u p e r PL S L C D - http://www.oled-display.net/smd-showcase-super-pls-lcd-which-will-replace-ips-technology Super PLS LCD which will replace IPS technology Submitted by admin on December 2010

Samsung Mobile Display showcase the next generation LCD-TFT Display for smartphones. SMD shows in a sample the differents between the new Super Plan to Line switching display and the IPS technology. SMD suggest is claimed to have an improvement of about 100 percent in viewing angle and is 10 percent brighter.

The Super PLS Display support a resolution up to WXGA. SMD suggest a better performance but also the price is about 15 percent cheaper. SMD has 30 key patent at this new LCD technology. SMD start with the mass production in Q1 2011. The focus for this technology is the smartphone and tablet market.

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PenTile improved image sharpness

- http://en.wikipedia.org/wiki/PenTile_matrix_family PenTile matrix family refers to a family of patented subpixel matrix schemes used in electronic device displays. PenTile is a trademark of Samsung.

These subpixel layouts are specifically designed to operate with a proprietary set of subpixel rendering algorithms embedded in the display driver, allowing plug'n'play compatibility with conventional RGB Stripe panels.

PenTile RGBW technology adds a white subpixel to the traditional red, blue, and green subpixels in a color display allowing a brighter display using less power.

The PenTile RGBW layout uses each red, green, blue and white subpixel to present high-resolution luminance information to the human eyes' red-sensing and green-sensing cone cells, while using the combined effect of all the color subpixels to present lower-resolution chroma (color) information to all three cone cell types. Combined, this optimizes the match of display technology to the biological mechanisms of human vision. The layout uses one third of the number of subpixels for the same resolution as the RGB Stripe (RGB-RGB) layout, in spite of having four color primaries instead of the conventional three, using subpixel rendering combined with metamer rendering. Metamer rendering optimizes the energy distribution between the white subpixel and the combined red, green, and blue subpixels: W <> RGB, to improve image sharpness.

- http://www.nouvoyance.com/technology.html Display Design and the Human Vision System PenTile® technology is biomimetic, meaning it is designed to compliment the complex mechanics of the eye-brain system. As a simple example of eye mechanics consider how the eye utilizes the color blue. The eye has cone receptors that sense color and brightness, and discern patterns. These cones are sensitive to different wavelengths of color—primarily red, green, and blue. The blue cones detect mostly color (chroma) information, while the red and green cones do most of the work resolving images by discerning luminance, edges, and structural details of images, as well as contributing to color vision. The red and green cones are used independently, each cone seeing a "dot" of black and white—ignoring its color to produce high resolution luminance perception—and are used in opposition, comparing the amount of red versus green, to produce low resolution color perception.

The PenTile RGBW™ layout uses each red, green, blue and white subpixel to present high-resolution luminance information to the red and green cones, while using the combined effect of all the color subpixels to present lower-resolution chroma (color) information to all three cone types. Combined, this optimizes the match of display technology to the biological mechanisms of human vision.

Other human-vision factors such as the logarithmic representation of luminance values, variable resolution between the center and edge of vision, and the separation and compression of brightness and color differences are also exploited in the design of PenTile RGBW™ displays.

How are images rendered on a PenTile RGBW™ display?

The same image data drives both RGB stripe and PenTile RGBW™ displays. However, conventional RGB stripe displays render (draw) images by assigning a color and luminance (brightness) to an entire RGB-triplet as a whole pixel, adjusting its three RGB subpixels to set a single addressable point.

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e-Paper & e-Books Images on a PenTile RGBW™ panel are subpixel rendered, meaning they are drawn at the subpixel level (the individual points of light), rather than to the whole pixels of an RGB stripe display. In fact "pixels" in the traditional sense have been eliminated in PenTile RGBW™ displays; individual subpixels are not restricted to use in one pixel group, but instead participate in multiple "logical" pixels in their surrounding vicinity.

Subpixel rendering dramatically increases addressability and enables the sophisticated image processing used in PenTile RGBW™ displays.

Why add a white subpixel?

LCDs are highly inefficient. Because RGB color filters transmit only a small band of wavelengths, only a small percentage of the light generated by an LCD’s backlight is visible to the eye, which reduces brightness.

PenTile RGBW™ displays add a white subpixel to the RGB mix that is actually a clear area in the LCD with no color filter material; therefore nearly all of the light is transmitted through the white subpixel. PenTile’s sophisticated software algorithms capitalize on this efficiency to create sharp images and brighter displays.

The addition of white subpixels combined with increased subpixel width makes PenTile RGBW™ panels about twice as transmissive as comparable RGB stripe LCDs. PenTile® technology renders the same resolution as RGB stripe with 33% fewer subpixels The human eye perceives the resolution of the PenTile RGBW™ panel as the same as an equivalent RGB stripe panel, yet the PenTile® panel uses one-third fewer subpixels. Consider the figure below to understand how this is accomplished.

At the top is the PenTile RGBW™ layout; at the bottom RGB stripe. The circle at the bottom center demonstrates the finest pattern of vertical black and white lines an RGB stripe display is capable of rendering. This requires three columns (R + G + B) be turned "on" and an equivalent width of three columns be turned "off" to write one cycle of a black and white line. From a suitable distance this collection of color subpixels appears to the eye as a white line.

The top center circle shows the equivalent pattern of vertical black and white lines written to the PenTile RGBW™ layout. From a distance the array of color subpixels in two columns will appear to the eye as a white line, identical to that generated by the RGB stripe layout, and the following two columns will write the corresponding black line. With only four columns being used to accomplish the same linear cycle that required six columns for legacy RGB stripe, two columns are saved. Hence, PenTile RGBW™ technology maintains the same resolution with one-third fewer columns, one-third fewer subpixels and one-third fewer transistors in the array. This results in wider columns and improved aperture ratio (ratio of transmissive area of a subpixel to the total area of that subpixel).

The circles on the right of the figure demonstrate the finest pattern of black and white lines which may be written horizontally to RGB stripe (bottom) and PenTile RGBW™ (top). Note that both layouts require the same number of rows for horizontal lines.

Copyright ©2008 Nouvoyance, Inc. All Rights Reserved.

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Subpixel rendering improved image sharpness

- http://en.wikipedia.org/wiki/Subpixel_rendering Subpixel rendering is a way to increase the apparent resolution of a computer's liquid crystal display (LCD) or Organic Light Emitting Diode display by rendering pixels to take into account the screen type's physical properties. It takes advantage of the fact that each pixel on a color LCD is actually composed of individual red, green, and blue subpixel stripes to anti-alias text with greater detail or to increase the resolution of all image types on layouts which are specifically designed to be compatible with subpixel rendering.

Demonstration of subpixels. Š 2004 David Remahl. -

http://en.wikipedia.org/wiki/File:Subpixel_demonstration_(Quartz).png

This is an illustration of subpixel rendering. The first column displays the original text at 100% size. A part of the text has been magnified 600% (each pixel in the magnification is 6Ă&#x2014;6 pixels) in a regular image editing program. The upper image does not use subpixel rendering, but does use anti-aliasing. It is completely grayscale. The lower does use subpixel rendering. At the edges of the strokes of the letters there is noticeable colour deviations. The normal-sized subpixel rendered text should appear significantly sharper than the regularly rendered text, but only on a TFT display with RGB subpixels in that exact order.

The second column displays the pixels as they would look if one enlarged an image of the monitor. The white pixels do not appear white, since the display elements are red, green and blue. In the regular rendition, the red, green and blue pixels are only controlled in triplets, i.e. a triplet of subpixels must have the same colour value. There is no such restriction in the subpixel rendered version, below.

The third column shows, enlarged, how the text is perceived when the light from the red, green and blue pixels mix and form various shades of gray.

The text was generated by the Quartz engine used by Mac OS X. Microsoft's ClearType subpixel rendering technology would have produced slightly different results, but the principle is the same. The font used for the example is Optima. Helvetica Neue is used for the labels.

How the image above was created First, Apple's text editing program TextEdit was used to draw the text at 12 and 18 pt (72 dpi) and captured by taking a screenshot. The images were imported in Photoshop and positioned. The two images were then duplicated and scaled up with nearest-neighbour sampling, 600%. http://en.wikipedia.org/wiki/File:Subpixel_demonstration_(Quartz).png

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Cholesteric Liquid Crystal Display Technology (ChLCD) - http://www.epapercentral.com/epaper-technologies-guide Cholesteric materials are modified liquid crystals and extremely suited for reflective, bistable displays. A cholesteric liquid crystal is a type of liquid crystal with a helical (smooth curve like a spiral) structure..

Cholesteric liquid crystals are also known as chiral nematic liquid crystals. While solids have molecules that maintain their orientation., molecules in liquids change their orientation and move anywhere in the liquid.

Some substances exist in an odd state that is similar to both liquid and solid. When they are in this state, the molecules tend to maintain their orientation, like solids, but can also move like a liquid. Liquid crystals are such materials. However, in essence they are more like a liquid and require only a little heat to move from this odd state to a liquid state.

□□□□□ - http://jp.fujitsu.com/group/labs/en/business/activities/activities-4/e-paper_p04.html Cholesteric Liquid Crystal Material Cholesteric Liquid Crystal only reflects light with certain wavelengths. When the light from sources such as the sun and light bulbs enter the liquid crystal, it displays in full color by reflecting light with the specific wavelengths of red, green, and blue.

Resultant color of red/green/blue mixture is determined by additive color mixture principle. When only red is reflected, it will appear red. When red and green are reflected, it will appear yellow. When all colors are reflected, it will appear white. When none are reflected, it will appear black.

How does the display work?

By applying electric power to transparent electrodes of each liquid crystal layer, liquid crystal molecules change directions, allowing the display to switch between reflect and not reflect.

More in Detail (1)- Liquid crystal molecules are formed in a spiral like structure. Normally, they are lined up vertically.

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e-Paper & e-Book (2)- By applying low voltage to the portion that the light needs to pass through, spiral shaped molecules turn horizontal. The horizontal position will be stable even after the voltage is turned off.

(3)- To the portion that the light has to be reflected, higher voltage is applied, making the spiral shaped molecules stretch. When the voltage is turned off, the molecules kickback, making the spirals vertical and stable. (Returns to the state in (1) )

Merits of cholesteric liquid crystalâ&#x20AC;&#x2122;s characteristics Ultra low power consumption and image memory function Since cholesteric liquid crystal is stable when the spiral axis is vertical or horizontal, direction of liquid crystal molecules can be maintained semi-permanently without power. This memory characteristic allows for power consumption only when rewriting, realizing the ultra low power consumption. Since no power is applied after an image is displayed, there is no flickering, making it easy for human eyes to see.

Thin, Light, and Bright Thin, light, and bright display is realized since components that are in conventional LCD (polarization plate, reflectors, color filters, and backlight) are not necessary.

- http://www.fujitsu.com/global/news/pr/archives/month/2010/20100507-01.html Massimo Marrazzo - biodomotica.com 53

e-Paper & e-Books Fujitsu Dramatically Enhances Color Electronic Paper Functionality

Display image comparison of Fujitsu's new version vs. previous-version color e-paper.

Cholesteric LCD panel employed in Fujitsu's color e-paper structure

- http://www.physorg.com/news192461210.html Fujitsu Dramatically Enhances Color Electronic Paper Functionality

- http://www.epapercentral.com/epaper-technologies-guide A unique feature of the CH-LCD technology is that not only does it reflect light, but also infrared. Thus, the display can be read with night vision goggles. One of Kentâ&#x20AC;&#x2122;s earlier products was used by the military.

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Flexible LCD - http://www.digitimes.com/news/a20071214PD205.html Taiwan's Industrial Technology Research Institute (ITRI) recently debuted its latest flexible display technology, including a color 10.4-inch cholesteric LCD (Ch-LC) flexible display and a flexible LED backlighting unit (BLU).

TRI color 10.4-inch Ch-LC flexible display Photo: Digitimes

□□□□□ - http://www.kentdisplays.com/technology/reflextechnology.html What is Reflex™ Technology?

All Kent Displays LCDs, glass and plastic, carry the Reflex brand. Reflex LCDs possess two major attributes that provide significant advantages over traditional liquid crystal displays: no power image retention and superior optical characteristics. They are also rugged, thin, and in the case of Reflex plastic LCDs, flexible.

Reflex LCDs utilize cholesteric liquid crystals, producing an image from reflected light. Cholesteric liquid crystals are bistable, exhibiting both a bright reflecting state and a dark non-reflecting state without any voltage applied. Because of bistability, Reflex LCDs will retain an image indefinitely without power. Some Reflex displays have retained the same image without power for over 10 years with no degradation.

No power image retention makes Reflex displays ideal for use in battery-operated, portable devices such as: • eReaders • MP3 players • Cordless and cellular telephones • Remote controls • Active inventory tags • Handheld GPS receivers At 60 microns, the thickness of Reflex plastic displays is comparable to the following: • Copy paper (100 microns) • Newsprint (45 microns) • Human hair (50-85 microns) • LAN fiber optic wire – core (62 microns) • Household aluminum foil (9-25 microns) Reflex glass displays are also thin, with a minimum thickness of 90 microns.

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e-Paper & e-Books - http://www.kentdisplays.com/products/lcdwritingtablets.html Reflex™ LCD Writing Tablets No more paper, pencils, or pens. Reflex™ LCD Writing Tablets are the environmentally-friendly alternative that replaces them all! Simply press on the surface with a stylus or other suitable writing instrument (even your finger) to create an image and then erase with the push of a button. By utilizing Reflex technology, no power is used retain the image, only to erase (typically supplied by a 3V watch battery).

OEM Boogie Board LCD Writing Tablet Boogie Board LCD Writing Tablets can be custom designed to integrate into a wide variety of other products including consumer electronics, toys, entry signs, appliance fronts, car visors, tools and more.

White writing on black background (Portable) white/black, black/green or blue, Color: orange/red, blue/yellow (OEM) Contrast: High Curvature: Wraps to 25 in diameter maximum (OEM) Life: 50,000 erase cycles Power: 0.19mW/cm2 for 1.8 second (only required for erase) 0.32 mm (Portable) Thickness: ~65 microns (OEM) 0.03 g/cm2 (Portable) Weight: 0.0089g/cm2 (OEM)

□□□□□ - http://www.zbdsolutions.com/aboutus/technology.html The Zenithal Bistable Display (ZBD®) is the first commercially available LCD that uses surface bistability. It has the same basic construction as the conventional twisted-nematic (TN) display used in watches. Two glass, or plastic, substrates with ITO electrodes on both internal surfaces, over-coated with a polymer layer to provide alignment to the liquid crystal, are spaced about 5 micron apart.

ZBD is a simple nematic LCD that uses grating alignment to produce zenithal bistable states with differing director pre-tilts. It offers ultralow power, image retention even after shock, and an appearance that surpasses that of STN. Ultimately, the device is ideal for portable products, such as electronic books.

A 2cm x 2cm reflective ZBD in the unpowered state.

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Device geometry for the reflective mode ZBD.

ZBDÂŽ used in a retail signage application (epopâ&#x201E;˘). http://www.zbdsolutions.com/resources/downloads/white_papers/40-1_Jones_SID_07.pdf

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OLED vs TFT-LCD Technology - http://www.interds.com/oled.php OLED (Organic Light-Emitting Diode) is a self light-emitting technology composed of a thin, multi-layered organic film placed between an anode and cathode. In contrast to LCD technology, OLED does not require a backlight. OLED possesses high application potential for virtually all types of displays and is regarded as the ultimate technology for the next generation of flat-panel displays.

The use of OLED technology offers the following advantages for flat-panel displays.

1. A simplified manufacturing process compared to TFT-LCD 2. Self-emitting light, in contrast to the required backlight for TFT-LCD 3. High luminosity 4. Lightweight and thin (less than 2 mm) 5. Capable of wide viewing angles (~180°) 6. Low operating voltage and power consumption 7. Quick response (~ ì second level) 8. Wide range of operating temperatures (-40°C to 8 5°C) A Comparison of OLED and TFT-LCD Display Technologies

OLED Display

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e-Paper & e-Book How Does OLED Emit Light?

OLED's basic structure consists of organic materials positioned between the cathode and the anode, which is composed of electric conductive transparent Indium Tin Oxide (ITO). The organic materials compose a multi-layered thin film, which includes the Hole Transporting Layer (HTL), Emission Layer (EML) and the Electron Transporting Layer (ETL). By applying the appropriate electric voltage, holes and electrons are injected into the EML from the anode and the cathode, respectively. The holes and electrons combine inside the EML to form excitons, after which electroluminescence occurs. The transfer material, emission layer material and choice of electrode are the key factors that determine the quality of OLED components.

□□□□□ - http://www.techgoo.net/2010/05/15/amoledoled-vs-tft-lcd/ AMOLED/OLED vs TFT LCD Posted by Rahul on May 2010

AMOLED stands for Active Matrix Light Emitting Diode.

LED is the future of displays, in televisions,mobile phones and all other gadgets using a display.LED displays are better than LCD (TFT) displays in nearly every field,whether it is viewing angle,power consumption,or even slimness.

Comparison of AMOLED and LCD in different fields: 1)Brightness of screen: LED displays are brighter as compared to LCD displays and are even less stressful for the eyes to view for a longer period of time.

2)Viewing angle: You may find that if you walk around to the sides of your LCD TV,the display becomes less clear and appears as a grey band when very close to 180 degrees,but for LED displays, the picture remains as clear and vivid at moderate viewing angles and only exhibits the behavior of LCD displays slowly at large angles.

3)Power consumption LCD screens require a backlight whereas LED displays operate without a backlight, thus they consume less power as compared to LCD displays and thus a device can run for a larger amount of time on the same battery(30-40% more for AMOLED).

4)Vividness of display and Blacks You may observe that on LCD displays,blacks do not appear like those in normal life,they are not very dark and in some cases appear more like grey than black.This is because the black in an LCD display has a light behind it and hence it cannot be totally dark,whereas for LED displays,the pixel which is supposed to display black becomes an _off-pixel"(that spot turns off),so blacks are sharp and very dark.

Colors on an LED display are more vivid and pleasant than LCD and LED displays have superior contrast ratios and lesser response times,thus reducing blur effects.

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e-Paper & e-Books 5)Sunlight legibility This is a debatable category and in many cases,sunlight viewability of LCD screens is better than that of LED screens but generally when it comes to AMOLED displays,they have better readability in sunlight.

6)Cost AMOLED screens are more expensive than TFT LCD screens,but the difference does not amount to much considering the small size of displays on mobile phones.But when it comes to large television screens,the cost difference is significant.

7)Lifespan Lifespan of AMOLED displays is lesser than LCD displays.But with the average rate of replacement and upgrading of gadgets such as mobile phones and televisions,this is not much of an issue.

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Electronic paper / E-paper / E-inkď&#x203A;&#x161;

by Emily Cooper - http://www.cooperhawk.com/contact.htm

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Bichromal technology - http://en.wikipedia.org/wiki/Gyricon Gyricon is a type of electronic paper developed at the Xerox PARC (Palo Alto Research Center). It has the same properties as paper: It's flexible, contains an image, and is viewable from a wide angle, but it can be erased and written thousands of times.

A Gyricon sheet is a thin layer of transparent plastic in which millions of small beads, somewhat like toner particles, are randomly dispersed. The beads, each contained in an oil-filled cavity, are free to rotate within those cavities. The beads are "bichromal," with hemispheres of two contrasting colors (e.g. black and white, red and white), and charged so they exhibit an electrical dipole. When voltage is applied to the surface of the sheet, the beads rotate to present one colored side to the viewer. Voltages can be applied to the surface to create images such as text and pictures. The image will persist until new voltage patterns are applied.

http://www2.parc.com/hsl/projects/gyricon/ Electronic Reusable Paper

http://screenweb.com/index.php/channel/4/id/3260

Bichromal Balls PARC first produced Gyricon bichromal balls in black and white, but the technology eventually included other colors.

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The beads, each contained in an oil-filled cavity, are free to rotate

The ink particles will move vertical towards the electrode

Schematic illustration of the rotating bichromal microsphere system (a) and the electrophoretic image display system (b)

Schematic illustration of the microencapsulated electrophoretic display system See â&#x20AC;&#x153;electrophoretic technologyâ&#x20AC;? pag. 66 Trends in Microencapsulation Research KONA No.22 (2004) Hidekazu Yoshizawa Department of Environmental Chemistry andMaterials, Faculty of Environmental Science and Technology, Okayama University - http://www.kona.or.jp/search/22_023.pdf http://www.eurosklep.pl/download/22_023.pdf

and see also: Particle-based display technologies - Ian Morrison Cabot corporation http://www.nanoparticles.org/pdf/22-Morrison.pdf

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Electrophoretic technology Black/white electrophoretic display http://www.epapercentral.com/epaper-technologies-guide Electrophoresis is a process, which enables separating molecules according to their size and electrical charge by applying an electric current. In an electrophoretic frontplane small, charges submicron particles are suspended in a dielectric fluid that is enclosed into a sub-pixel size cell or microcapsule. When an electric field is applied across this cell or capsule, the ink particles will move towards the electrode with the opposite charge.

The Basics of Electrophoretic Displays http://trappist.elis.ugent.be/ELISgroups/lcd/tutorials/tut_eink.php The term electrophoresis is a composition of 'electro' and 'phoresis', two words that are derived from the Greek words for 'charge' and 'the act of carrying'. In that way, the name 'electrophoretic display (ED)' already gives a hint about its basic working principle. As shown on the picture below an ED is made of an ink layer, sandwiched between two layers that can be plastic, glass or even paper. The total thickness of the layer structure is between 0.5mm on glass and 0.1mm on plastic, which is in the order of a sheet of paper.

Principle of an electrophoretic display In the simplest case of a black and white display, the top substrate is covered with a single transparent electrode, while the bottom substrate contains a complex pattern of line-electrodes. Using active matrix driving, a single pixel can be addressed, meaning that the bottom electrode can be made either positive or negative compared to the top-electrode. The electrophoretic ink between these electrodes is a mixture of transparent liquid and microscopic charged pigment particles. The usual choice is negatively charged black particles (carbon black) and positively charged white particles (TiO2). In practice the ink is captured inside microcups, or microcapsules as in the figure. When a voltage is applied over the top- and bottom electrode, the charged pigments will move due to an electrostatic force to the attracting electrodes. For instance, when the bottom electrode is positive, it will attract black particles and repel white particles. These white particles gather at the top-electrode, where they reflect incident light in all directions. This is the white state. In the opposite case a negative bottom electrode pushes the black particles to the surface, where they absorb the light. This is the black state. This basic principle is different than most displays by the fact that it is reflective.

So, an ED is a type of display that reflects or absorbs ambient light in contrast to transmissive displays such as the CRT or LCD. In practice this looks like:

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MIT media lab

40 Micron = diameters of the microcapsule Microparticles inside microcapsule contain pigments like titanium dioxide and carbon black

How Does E Ink Work?

E Ink is short for “electrophoretic ink”. Technically speaking, charged pigments suspended in a clear liquid micro-capsule respond to a voltage that moves black or white pigments to the screen’s foreground. The technology differs from traditional displays because electrophoretic displays reflect light, rather than emitting it. Computer displays and mobile phone screens rely on a backlight to illuminate pixels of different colors, while E Ink technology leverages ambient light just like ink on paper. With E Ink’s patented and proven bistable technology, images and text will remain on the screen even without power.

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□□□□□ Microcup® Electronic Paper - http://www.sipix.com/technology/microcup.html The SiPix Microcup® The SiPix Microcup® is a microscale container which holds minute quantities of materials such as fluid and particles. Large arrays of Microcups® are fabricated through roll-to-roll© manufacturing processes which enable economy and scale. The material is flexible, is easily cut to size, and enables many custom applications by electronic paper.

Structure The Microcup® structure is typically 150 µm thin and is significantly resistant to impact and pressure due to its architecture of supporting walls. It is built upon a layer of flexible PET plastic, which may include a transparent conductor such as Indium Tin Oxide (ITO). The contents of the Microcup® are hermetically sealed to protect them from the environment.

□□□□□ - http://www.sipix.com/technology/epaper.html One application of the SiPix Microcup® is flexible, low-power electronic paper module. This module is highly reflective and may be used to produce with paper-like readability. Unlike existing display technologies, SiPix e-paper has image memory - the display content remains after the power has been removed. Due to this benefit, extremely low-power portable devices may be created. Because of the Microcup® architecture, SiPix e-Paper is known to be environmentally robust and highly resistant to impact and pressure.

Fabrication SiPix e-paper is created by inserting electrically-charged white particles and dielectric fluid within the Microcup® during roll-to-roll© manufacturing. Once the e-paper is laminated to a patterned conductor with adhesive (see illustration below), the e-paper display may be driven. Note that the visible side is the bottom layer of the Microcup® manufacturing process

© SiPix Imaging, Inc. & SiPix Technology, Inc.

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e-Paper & e-Book Optical Principles Under the influence of an applied electric field, the charged particles migrate through the dielectric fluid. If the white particles are at the visible surface, that area of the display reflects a white color to the viewer.

Otherwise, the display will reflect the alternate color, which presently is either black, red, green blue, or gold.

Grayscale may be produced by modulating the electric field across the Microcup® film.

Both monochrome and area color displays may be produced with SiPix e-Paper. Our material has a viewing angle that is approximately 180°.

□□□□□ - http://techon.nikkeibp.co.jp/article/HONSHI/20091222/178805/?P=4 Microcup Design The key element in the e-paper film from SiPix Imaging is microcups, a proprietary technology.

C.T. Liu, Senior Vice President, Au Optronics Corp. Jan 2010

Basically, these tiny chambers are filled with white particles and colored liquid . The particles are brought to the surface or submerged to change the microcup color to white or color, accordingly. If the liquid is black, then the display shows standard black-and-white monochrome imagery. By changing the color of the liquid, a variety of two-color displays is possible

The film is covered with tiny microcups, each filled with particles and liquid. The motion of the particles changes the displayed color.

E-Paper Film Production Process] SiPix Imaging e-paper film is manufactured roll-to-roll.

Copyright © 1995-2010 Nikkei Business Publications, Inc. All rights reserved.

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Flexible e-Paper Display - http://www.pvi.com.tw/en/products/p063.php PVI's flexible e-Paper is lightweight, slim, easy to handle and virtually unbreakable; offering enhanced choices and convenience to the reader, while providing greater freedom for industrial designers.

 Prime View International Co., Ltd.

The displays are based on PVI's proprietary MagicMirror® Reflective Technology together with the EPLaR process, developed by Philips Research, and for which PVI currently has an exclusive license. MagicMirror® provides efficient and high quality reflective TFT backplane manufacturing, while the EPLaR process enables all PVI’s proprietary a-Si TFT and module processes to be applied in making flexible e-paper displays.

This is the world's first flexible active matrix (AM) electrophoretic display made in a volume TFT fab, and is set to trigger a new wave in the e-reading revolution. As interest in flexible displays intensifies, PVI has broken new ground in this area, spearheading a crucial step forward in development.

□□□□□ http://www.electronista.com/articles/10/04/21/prime.view.involved.in.both.kindle.and.ipad/ E Ink parent company also contributing to iPad panels April 2010

The same company that makes the E Ink displays is also involved in making the iPad's screen, according to a statement made Wednesday (subscription required). Prime View International (PVI), whose E Ink division makes screens for the Kindle and Nook, said its sub-label Hydis was responsible for developing the in-plane switching (IPS) panel technology crucial to the wide viewing angles with Apple's tablet. LG Display is believed responsible for actually manufacturing the finished screen and signed a deal with PVI in December.

□□□□□ - http://www.islate.org/2010/03/21/kindle-3-may-get-color-with-pvi-e-ink-screen/ Kindle 3 may get Color with PVI E-Ink Screen

by Nick Schooler in iSlate

Prime View International (PVI) who makes the e-ink displays for Amazon’s Kindle showed 6 and 9.7-inch color E-ink prototypes at a trade show in China this week Taiwan-based Prime View International (PVI) , the company who makes the displays for Amazon’s Kindle, is now showing off its 6-inch and 9.7-inch color e-ink displays for eBook readers at a trade show in Shenzhen, China. he smaller screen was playing a clip of animated red and blue racecars driving on a track, though a PVI spokeswoman said the color screens cannot play real video because their pixels refresh too slowly. PVI has already shown the screens to Amazon and Barnes & Noble, though there wasn’t any confirmation as to whether it will be used for future eBook readers.

The news follows earlier comments from PVI’s VP of marketing that color E-Ink devices would begin shipping in Q1 2011.

While the 6-inch E Ink panel was apparently being fed a video to display, PVI concede that the technology is not currently at a level to show smooth footage and at the moment not ready to steam full video.

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A4-size - http://www.fareastgizmos.com/other_stuff/electronic_papers_to_replace_traditional_papers_very_soon.php Epson unveiled a 13.4-inch (A4-size) electronic paper at SID 2008, in Los Angeles, the US. Its pixel count is 3104 Ă&#x2014; 4128 and definition is as high as 385ppi. Before this the company's largest paper was a 7.1-inch type. The new electronic paper was developed by combining electrophoretic electronic ink of E Ink Corp and a low-temperature polycrystal Si-TFT of Seiko Epson. The TFT was formed on a glass substrate. Its contrast ratio is 10:1 and reflectance is 40%. With this prototype, Seiko Epson considers that the company entered the final stage of replacing traditional papers with electronic papers.

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QR-LPD http://hat-lab.ed.kyushu-u.ac.jp/Documents/SID2006_68_2.pdf SID2006 - Color and Flexible Electronic Paper Display using QR-LPD.pdf It consists of electrodes, ribs and powder. When a negative voltage is applied to the upper transparent electrode, the positively charged black particle moves to the upper electrode exhibiting a black appearance and, in the opposite case, the negatively charged white particle is attracted to the upper electrode exhibiting a white appearance. The white appearance of QR-LPD® derives from the reflection at the surface of electronic liquid powder on the upper substrate. This leads to paper-like appearance and wide viewing angle of QR-LPD®

Reflective Color Displays.

One method is applying colored liquid powder, the other is applying color filter technology with black and white liquid powder.

□□□□□ - http://www2.bridgestone-dp.jp/global/adv-materials/QR-LPD/future.html Characteristics of Flexible Electronic Pape

Thickness : Comparison with glass 1/5 (In-house ratio) Weight : Comparison with glass 1/10 (In-house ratio) High Durability : For safety Manufacturing Process of Flexible Electronic Paper

We have developed a "Roll to Roll" process that excels in productivity.

Since it is not necessary to form the TFT (Thin Film Transistor) required for most displays, it is an ideal process.

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http://www.crunchgear.com/2010/04/29/qr-lpd-bridgestones-flexible-e-paper-video

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Colored electrophoretic display E Ink Color Active Matrix - http://eink.com/display_products_triton.html E Ink Triton Imaging Film Color Active Matrix E Ink continues to revolutionize the ePaper market with E Ink Triton Imaging Film. Color ePaper displays enabled by Triton deliver high-contrast, sunlight readable, low-power performance that further closes the digital divide between paper and electronic displays. Triton enables color ePaper solutions, enhancing the visual experience for ePublishing markets such as eBooks, eNewspapers, eMagazines, and eTextbooks.

Enhanced With Color In addition to 16 levels of monochrome, Triton is capable of displaying thousands of colors. For image-rich information applications showing charts, graphs, maps, photos, comics and advertising, color displays made with Triton Imaging Film enable ultra low power and high mobility devices with a paper-like experience. And just like E Ink's monochrome ePaper products, Triton's crisp text and detailed color graphics are fully viewable in direct sunlight.

Improved Speed Both E Ink Triton as well as E Ink Pearl, are both 20% faster than previous generations of E Ink Imaging Film. Whether turning a page, selecting a menu, taking notes, or viewing an animation, Triton's update performance will satisfy today's user-interface product needs. This expands the ePaper experience and display more dynamic content for signage, advertising, or browsing the Internet.

Tier 1 Ecosystem E Ink has partnered with tier-1 companies such as Epson, Texas Instruments, Marvel, and Freescale Semiconductor to provide a best-in-class ecosystem of supporting electronics products. Our partners are working towards enabling E Ink's newest generation of ePaper displays with solutions like dedicated discrete ePaper controllers and display power management integrated circuits. E Ink has continued to advance the state of the art and provide design flexibility to product manufacturers.

Recently, Seiko Epson Corporation ("Epson", TSE: 6724) a global supplier of imaging products and semiconductor solutions, and E Ink Corporation, announced the first jointly developed controller IC to support E Ink Triton-enabled color ePaper displays. The S1D13524 is a high-performance EPD controller with a built-in color processor that enables seamless integration of color ePaper displays into a variety of devices.

Applications E Ink Triton Displays are ideal for a variety of dynamic content applications including: Readers â&#x20AC;&#x201D; eReaders, eTextbooks, eNewspapers, eMagazines, eDocuments Wireless devices â&#x20AC;&#x201D; remotes, game controllers Thermostats and Industrial Displays Mobile point of sale units (signature pads) In-store signage 72 Massimo Marrazzo - biodomotica.com

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□□□□□ - http://www.switched.com/2010/08/13/e-ink-begins-to-sample-capacitive-color-e-readers/ E Ink Begins to Sample Capacitive, Color E-Readers

It appears that color E Ink readers aren't as far from being commercially available as most have thought. E Ink Holdings (formally PVI), the group responsible for the screens housed in Amazon's Kindle and Sony's Readers, is leading the way by offering samples of its color panels to manufacturers. In addition to creating color-capable displays, the new screens are capacitive, meaning all their touch-based interactions will be drastically improved.

- http://www.eink.com/readable.html

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e-Paper & e-Books - http://findebookreaders.com/blog/2010/11/how-e-ink-holdings-triton-display-works/ How E Ink Holding’s Triton Display Works This diagram is from E Ink Holding and shows how the Triton e-ink display works. E Ink also has released a video.

E Ink Triton Color Imaging Film With the E Ink Triton color configuration, a thin transparent colored filter array (CFA) is added in front of the black and white display. Now the display can also reflect color. The CFA consists four sub-pixels – red, green, blue, and white – that are combined to create a full-color pixel. The result? A low-power, directsunlight, readable color ePaper display that is mass manufactured in a practical way.

□□□□□ - http://vimeo.com/16625704

E Ink Triton Imaging Film

□□□□□ - http://www.eetimes.com/electronics-news/4210601/E-ink-unveils-color-ePaper

E-Ink unveiled its long-anticipated color version of its low power ePaper displays that use filters to impart color it its paper-white films.

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In-plane electrophoretics - http://nextbigfuture.com/2009/05/e-books-with-larger-screens-and-soon.html MIT Technology Review reports A new approach developed by Philips now offers fresh hope for color epaper displays that are so bright and clear that even traditional liquid crystal displays (LCDs) will pale in comparison.

Philips's technique, which is called in-plane electrophoretics, differs in that it involves suspending colored particles in a clear liquid and moving them horizontally instead of vertically. Each pixel is made up of two microcapsules chambers: one containing yellow and cyan particles, the other, below, containing magenta and black particles. Within each microcapsule, one set of colored particles is charged positively while the other is charged negatively.

By carefully controlling the voltages at electrodes positioned on the edges of the pixels, it is possible to spread the colored particles across the pixel or remove them from view altogether by hiding them behind the electrodes. This means that different shades of color can be achieved by controlling how many of each group of colored particles are visible. To create white, all of the particles are simply shifted to the side to reveal the white substrate beneath the two microcapsules.

□□□□□ - http://www.sid.org/jsid_previews.html A solution for a full-color electronic paper is shown in figureconsisting of two layers with each two colors of particles. Excellent white is obtained by the white reflector (while both layers are switched to transparent), excellent black by the black particles, and all colors can be made by combinations of cyan, magenta, and yellow particles.

Horizontal motion Schematic illustration of a full-color concept for electronic paper that also provides an excellent black state and white state.

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e-Paper & e-Books - http://goodereader.com/blog/electronic-readers/pvi-color-e-ink-display-to-make-year-end-debut/ PVI Color E-Ink Display to make year end debut

By Sovy

Prime View International, makers of Electrophoretic display or EPD seems to be in a hurry with their color E Ink project and have set a December 2010 time line by which time it wants products graced with its color E Ink display to make it to the market. The new deadline has been revealed by none other than the company chairman Scott Liu and is a few months ahead of the 2011 first quarter deadline that was earlier envisaged.

The latest e-reader news has it that the color displays are in an advanced stage of development and samples have already been provided to leading e-reader manufacturers which includes Amazon and Barnes & Noble among others though there is no definite partnership reached with any e-reader manufacturer as of now. Also, with Amazon CEO Jeff Bezos almost ruling out color kindles – he was recent quoted as saying a color Kindle is “a long way out” – its highly unlikely for a PVI color E Ink display to feature in a Kindle anytime soon.

In the meantime, the third quarter of this year will see the launch of a fresh batch of e-readers equipped with PVI’s monochrome display though most of the action is likely to be restricted to the Chinese market. PVI too has high hopes of the e-reader market in China and is extremely bullish of a strong performance there. The company believes the e-reader market in China is expected to grow to become 20 percent of the world ereader market. It was late last year that PVI had acquired the Boston based E Ink Corp. in a deal worth US $215 million. PVI used to be the largest customer of E Ink and it alone accounted for more than half of E Ink’s total revenue before the acquisition. Now with E Ink under the control of PVI, anyone who is into manufacturing of e-readers and wants E Ink will have to turn to PVI.

□□□□□ - http://news.softpedia.com/news/PVI-Developing-Touch-and-Animation-Capable-Flexible-EPDs-134159.shtml

PVI Developing Touch and Animation-Capable, Flexible EPDs February 2010 By Sebastian Pop Copyright © 2001-2010 Softpedia.

Prime View International is planning on developing a number of new types of electrophoretic displays (EPD).

This technology would be different from the one used in current products, where the touch panel is added on top of the screen. Among the examples given by Liu were Sony's e-reader, with resistive touch technology, Hanwang products, with electromagnetic touch panels, and other devices that employed capacitive touch functions.

PVI is also developing color EPDs for use in e-readers. While the chairman did mention that e-readers had, thus far, not been able to support animation because of their very low response time, improvements had been made in this area and animation support should emerge during the ongoing year.

The company is also planning on developing and mass-producing flexible EPD screens. In their creation, according to Liu, PVI will be using its existing TFT LCD equipment “plus a small amount of extra tools.”

Flexible displays will give way to new types of consumer electronics and might allow current products to become more versatile.

Color and flexible screens may prove to be an especially profitable venture, especially considering the popularity of e-readers and the rapid growth predicted for tablets. In fact, a recent study found that a fair amount of consumers would like to see e-readers equipped with color capabilities, among other things. Of course, it remains to be seen if adding animation support to e-readers will not have too great an impact on the battery life, which is another area where customers would like to see improvements.

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PVI plans to develop color, flexible and animation-capable e-reader screens Image credits: www.wikimedia.org

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Electrowetting Technology (EW) - http://www.epapercentral.com/epaper-technologies-guide Electrowetting is based on controlling the shape of a confined water/oil interface by an applied voltage. With no voltage applied, the (colored) oil forms a flat film between the water and a hydrophobic (water-repellent), insulating coating of an electrode, resulting in a colored pixel. Applying voltage between the electrode and the water causes the interfacial tension to change, which causes the water to move the oil aside. The result is a partly transparent pixel; if a reflective white surface is used under the switchable element, a white pixel results. This forms the basis of the reflective display.

- http://www.slashgear.com/liquavista-flexible-color-display-prototypes-unveiled-video-27110461/ First Liquavista Flexible Display Prototype

By Chris Davies on Wed Oct 27th, 2010

Demonstrates true versatility of electrowetting display technology 26 October 2010 – Eindhoven – Today, Liquavista BV., announced the creation of the first flexible electrowetting displays. These prototypes demonstrate yet another dimension to the versatility of Liquavista’s display technology, adding lower weight, robustness and conformability to the bright, colourful low power video capabilities.

“We’re really excited to be able to demonstrate yet another significant benefit of electrowetting display technology with the development of these prototypes.” Said Guy Demuynck, CEO Liquavista.

“Bringing to market a unique display that can run video in color at low power and has the added advantage of an unbreakable screen which is lightweight, thin, flexible and robust will enable consumer electronics manufacturers to increase the durability of devices, reduce manufacturing costs and create new product designs to open up new markets.

“This new prototype is a first important step in paving the way for high volume manufacture of displays on flexible substrates” added Johan Feenstra, Liquavista’s CTO and Founder, “This clearly demonstrates that electrowetting technology is not only compatible with standard glass substrates but can in fact be manufactured on any substrate. The pace at which we have been able to continue to show advanced technology features is further proof of the simplicity and versatility of our technology.”

Liquavista’s displays are based on the principles of electrowetting and bring bright and colourful images and video that ensures excellent indoor and outdoor readability but uses dramatically less 78 Massimo Marrazzo - biodomotica.com

e-Paper & e-Book battery power. The technology is uniquely suited for colour and video electronic paper displays because of its very high reflectivity and its intrinsically fast video-rate switching speed. It is ideal for manufacture on flexible substrates as it does not require high temperature processing, has no demanding encapsulation requirements and is independent on cell gap variations.

In the future, consumers will want products that not only support full color and video but offer readability in all lighting conditions and gives them the freedom and portability of paper. Liquavista’s displays possess all the features to fulfil this desire.

□□□□□ - http://www.nuovetecnologieblog.it/hardware/schermi-flessibili-il-primo-display-electrowetting-di-liquavista/

□□□□□ - http://www.liquavista.com/documents/getFile.asp?DocID=15 PDF file

Single-layer architecture A low cost, full color display can be fabricated with electrowetting using an RGB color filter approac.

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e-Paper & e-Books In this case, black-colored oil is required as an absorbing switch. Compared to MEMS or CTLC-based approaches, electrowetting offers the same performance in a simpler, lower cost structure.

Three-layer architecture A strong improvement in optical performance is obtained when three monochrome layers are placed on top of each other. Having three monochrome layers ensures that all processes used for the single-layer display can be used for the three-layer display as well.

□□□□□ - http://www.gizmag.com/video-capable-full-colour-e-ink-paper-electrowetting/17041/ E-ink evolves: full color, video-capable, easy on the eye and cheap enough to be disposable

By Loz Blain November 2010

E-ink's benefits over other forms of display are obvious: you don't have to backlight it if you don't want to, so it's very easy on the eye and also on a device's battery. You can effectively use it to produce an electronic screen that's as pleasant to look at as a printed piece of paper. And the technology seems set to take another leap forward with the announcement that University of Cincinnati researchers have developed an eink technology that's quick enough to competently display full color video – but so cheap that it can be completely disposable. How? Well, instead of using glass or flexible plastic as the basic substrate layer, they're using paper – and getting excellent results. So you could end up with single-page disposable electronic newspapers and magazines that use a tiny fraction of the paper their printed counterparts require.

The paper-based e-ink technology uses the electrowetting method, in which an electric field is applied to colored droplets in a display unit to effectively turn on and off pixels in an array. Unlike an electrophoretic display like the one used in Amazon's Kindle e-reader, an electrowetting screen is able to deliver full color, and it can refresh quickly enough to display video.

It uses very little power, it's low-voltage, but delivers high contrast and can be used to deliver exceptional brightness, up to four times brighter than a reflective LCD screen - not to mention that electrowetting screens can be made flat and very thin.

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e-Paper & e-Book Previously, the technique has required complex circuitry printed onto rigid glass or flexible plastic, but Electrical Engineering professor Andrew Steckl and doctoral student Duk Young Kim from the University of Cincinnati have discovered that you can get glass-like performance using a simple piece of paper as the substrate.

The end result will be a flexible, very cheap paper screen that can be sold as a disposable item like a newspaper or magazine. You could even print books on it, given a longer-lasting power source. It would be more convenient than a newspaper to read in just about any situation (but particularly on the train), and since it's cheap and disposable there'd be none of that paranoid feeling you get using an expensive iPad or Kindle in public.

“Nothing looks better than paper for reading,” said Steckl, an Ohio Eminent Scholar. “We hope to have something that would actually look like paper but behave like a computer monitor in terms of its ability to store information. We would have something that is very cheap, very fast, full-color and at the end of the day or the end of the week, you could pitch it into the trash.”

Whether or not the commercial applications of this technology end up being as cheap and effective as its inventors hope, paper-based electrowetting looks like a worthwhile and exciting addition to the portable display market. We look forward to seeing it in action.

Full press release at the University of Cincinnati website.

- http://pubs.acs.org/doi/abs/10.1021/am100757g The use of paper as a material for various device applications (such as microfluidics and energy storage) is very attractive given its flexibility, versatility, and low cost. Here we demonstrate that electrowetting (EW) devices can be readily fabricated on paper substrates. Several categories of paper have been investigated for this purpose, with the surface coating, roughness, thickness, and water uptake, among the most important properties. The critical parameter for EW devices is the water contact angle (CA) change with applied voltage. EW devices on paper exhibit characteristics very close to those of conventional EW devices on glass substrates. This includes a large CA change in oil ambient (90−95°), negligible hysteresis (2 °), and fast switching times of 20 ms. These results indicate the promise of low-cost paper-based EW devices for video rate flexible e-paper on paper.

- http://www.uc.edu/news/NR.aspx?id=12779 A discovery by University of Cincinnati engineering researcher Andrew Steckl could revolutionize display technology with e-paper that’s fast enough for video yet cheap enough to be disposable.

Date: 11/22/2010 By: John Bach Photos By: Dottie Stover; ACS Cover Illustration by Angela Klocke

In the research, Steckl and UC doctoral student Duk Young Kim demonstrated that paper could be used as a flexible host material for an electrowetting device. Electrowetting (EW) involves applying an electric field to Massimo Marrazzo - biodomotica.com 81

e-Paper & e-Books colored droplets within a display in order to reveal content such as type, photographs and video. Steckl’s discovery that paper could be used as the host material has far-reaching implications considering other popular e-readers on the market such as the Kindle and iPad rely on complex circuitry printed over a rigid glass substrate.

“One of the main goals of e-paper is to replicate the look and feel of actual ink on paper,” the researchers stated in the ACS article. “We have, therefore, investigated the use of paper as the perfect substrate for EW devices to accomplish e-paper on paper.”

“It is pretty exciting," said Steckl. “With the right paper, the right process and the right device fabrication technique, you can get results that are as good as you would get on glass, and our results are good enough for a video-style e-reader.”

Steckl imagines a future device that is rollable, feels like paper yet delivers books, news and even highresolution color video in bright-light conditions.

“Nothing looks better than paper for reading,” said Steckl, an Ohio Eminent Scholar. “We hope to have something that would actually look like paper but behave like a computer monitor in terms of its ability to store information. We would have something that is very cheap, very fast, full-color and at the end of the day or the end of the week, you could pitch it into the trash.”

The work was supported, in part, by a grant from the National Science Foundation and was conducted at the Nanoelectronics Laboratory at the University of Cincinnati College of Engineering and Applied Science.

http://www.printedelectronicsworld.com/articles/the_future_of_electronic_paper_fast_switching_full_colour_e_readers_00002034.asp?s essionid=1

The future of electronic paper: Fast-switching full-colour e-readers.

Article by Dr Harry Zervos

The electrowetting effect has been defined as "the change in solid/electrolyte contact angle due to an applied potential difference between the solid and the electrolyte".

The image below demonstrates the principles behind an electrowetting display. A voltage is used to modify the wetting properties of a solid material. An example of such increased wettability is illustrated below.

The top illustration shows a water droplet on a hydrophobic surface, with a minimized contact area.

In the illustration below, a voltage difference is applied between the electrode in the water and a sub-surface electrode present underneath the hydrophobic insulator material. As a result of the voltage, the droplet spreads, i.e. the wettability of the surface increases strongly.

Source: RSC Publishing

In a display a reflecting electrode, a hydrophobic insulator, a colored oil layer and water will be sandwiched between glass or polymeric substrates. In equilibrium the colored oil naturally forms a continuous film between the water and the hydrophobic insulator.

When a voltage difference is applied across the hydrophobic insulator, an electrostatic term is added to the energy balance and the stacked state is no longer energetically favorable.

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e-Paper & e-Book The system can lower its energy by moving the water into contact with the insulator, thereby displacing the oil and exposing the underlying reflecting surface.

Source: Liquavista

□□□□□ - http://physicaplus.org.il/zope/home/en/1185176174/water_elect_en

□□□□□ - http://www.liquavista.com/ - website of the Liquavista, a Philips Co. daughter company that develops display surfaces based on electrowetting http://www.liquavista.com/products/liquavistacolor.aspx

video

□□□□□ - http://www.ece.uc.edu/devices/NDL_Research.html In some ways, the flat panel display market is extremely mature. Wide-screen plasma and LCD TVs are now commonplace, and e-book technologies (e.g., the Amazon Kindle) are readily available as well. However, peo-ple who work outside displays may be surprised to learn that liquid crystal displays are typically less than 10 percent optically efficient, and the electrophoretic ink used in e-books is only about 40 percent reflective. There is therefore very good reason to pursue alternate display technologies.

Of the many new display technologies under investigation, arrayed electrowetting devices are particularly compelling. The first electrowetting display technology to capture researchers’ attention was the dye-colored oil film approach discovered by Hayes and Feenstra at Philips (now at the Philips spin-off, LiquaVista). This approach uses water covering a film of oil. The oil forms a film beneath the water because the water contact angle is very large (θY ~160 to 180°, so the contact angle for the oil is about 20° to 0°). When voltage is applied, this water electrowets the hydrophobic dielectric causing the oil to “de-wet” the surface. This reduces the viewable area of the oil from 100 to 20 percent. LiquaVista uses a reflective material beneath the display pixel that en-ables an active-matrix video display with reflectivity of greater than 50 to 60 percent.

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Electrofluidic technology (EFD) - http://gammadynamics.net/technology.html Electrofluidic displays place an aqueous pigment dispersion inside a tiny reservoir. The reservoir comprises <5-10% of the viewable pixel area and therefore the pigment is substantially hidden from view. Voltage is used to electromechanically pull the pigment out of the reservoir and spread it as a film directly behind the viewing substrate. As a result, the display takes on color and brightness similar to that of conventional pigments printed on paper. When voltage is removed liquid surface tension causes the pigment dispersion to rapidly recoil into the reservoir.

Comparisons of EFD performance and the electrophoretic technology common in e-books.

□□□□□ Flexible Electrofluidics - http://www.nanowerk.com/spotlight/spotid=18495.php Electrofluidics device uses sub-10nm nanochannels to analyze DNA

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e-Paper & e-Book - http://gammadynamics.net/technology/

□□□□□ - http://www.uc.edu/news/NR.aspx?id=12495 This patent-pending electrofluidics breakthrough by the Novel Devices Laboratory at the University of Cincinnati and partner companies Gamma Dynamics By: M.B. Reilly April 2010 Photos By: Lisa Ventre; design contribution by Angela Klocke

UC's Jason Heikenfeld, at left, and student Shu Yang demonstrate how the technology developed by UC can employ bright, incident light by reflecting it. Many of today's electronic devices, like the BlackBerry held by Heikenfeld, cannot do so.

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Two horizontal "boxes" above represent views of the new technology design - with the pigment dispersion fluid represented as "in motion." Ambient light enters via the device screen. When that light hits the layer of reflective electrodes, it is amplified.

UC student Shu Yang holds prototypes of the e-Display technology developed by UC.

- http://gammadynamics.net/news/aploct2010/ e-Paper based on â&#x20AC;&#x2DC;electrofluidicsâ&#x20AC;&#x2122; can now hold an image without electrical power October 2010

Cincinnati, OH: Displays for consumer electronic devices such as e-Readers, smart phones, and tablet PCs never quite meet all the demands of all the users all the time. Some lack color and video capability, others use too much battery power, while others are nearly unreadable pool-side. Researchers at the University of Cincinnati and a small start-up company, Gamma Dynamics LLC have described a break-through new approach creating electrofluidic displays that can hold an image without power consumption. Such breakthroughs are essential in the quest for creating more user and environmentally friendly electronics. And unlike the display in the Amazon Kindle, the technology can boast >70% white reflectance (close to paper which is 80%) and potentially video-speed operation. Electrofluidic displays are a variant of electrowetting displays, a technology that has been in development for 10 years, and until now, required electrical power to hold an image on the screen.

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e-Paper & e-Book The new breakthrough works by moving a colored fluid (similar to inkjet fluid) between the front and the backside of a reflective sheet. The space above and beneath this special sheet is similar in geometry enabling the fluid to remain stationary in any position without an applied voltage, as scientifically predicted by Laplace pressure. The team of engineers and scientists had realized this patent-pending concept several years ago, but what was lacking was a way to make it manufacturable. Manufacturability using the same equipment used for manufacturing LCDs is essential, because a new LCD factory now costs around $2 B. New technology needs to conform to the existing infrastructure. Fortunately, the Univ. of Cincinnati and Gamma Dynamics were able to team with DuPont engineers who are developing a new film that can be laminated and optically imaged to form holes, spacers, and other key features. As a result, the team was able to create complex features using equipment similar to that used for making simple printed circuit boards. Each pixel is about the same width as a human hair. The collaborative partnership does not end there. The team also works with Cincinnati’s Sun Chemical corporation on adapting inkjet fluids so they could be moved inside the tiny pixels. The movement of the fluids is best illustrated as shown on the cover of th Applied Physics Letters (Oct. 4 , 2010). Voltage is used to move colored fluid between an upper viewable cavity, and a lower hidden cavity, and importantly, the voltage can be removed and the fluid can sit in any intermediate position, otherwise known as grayscale pixel operation.

The Novel Devices Laboratory has been developing fluid-based devices for displays and other applications for industry and the military for about five years. Recently, the University of Cincinnati won a State of Ohio Third Frontier award to create the Ohio Center for Microfluidic Innovation (OCMI) which will expand the university and local industry capability in commercializing micro/electrofluidic technologies, including biomedical devices.

- http://www.epapercentral.com/electrofluidic-technology-enters-epaper-arena.htm Electrofluidic Technology Enters E-paper Arena May 2009

Innovations in the electronic paper arena seem to be coming fast and furious these days. The latest news concerns researchers at the Novel Devices Lab at the University of Cincinnati, who have recently demonstrated a new display technology, termed “electrofluidic,” that claims higher brightness than other technologies currently available on the market. The electrofluidic nomenclature is chosen because the mechanism involves charge-induced movement of liquids through microfluidic cavities.

While most electronic paper devices typically have a 40% (E Ink) to 50% (electrowetting) reflectance rate, the new device is said to reflect 55% of ambient light. For the future, that number could be improved to approach 85%, which is the reflectance ratio of paper printed with traditional inks. This could be an important breakthrough, because one of the stumbling blocks to wider acceptance of e-paper is that it still doesn’t approach the look of conventional ink on paper.

- http://www.technologyreview.com/video/?vid=325 See how the new e-paper design works.

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e-Paper & e-Books http://www.optoiq.com/index/photonics-technologies-applications/lfw-display/lfw-article-display/365403/articles/laser-focusworld/volume-45/issue-7/world-news/displays-electrofluidic-display-uses-brilliant-color-pigments.html

DISPLAYS: Electrofluidic display uses brilliant color pigments Gail Overton - Jul 2009

Researchers at the University of Cincinnati and Sun Chemical (both in Cincinnati, OH) have developed a lithographically fabricated electrofluidic display that uses visually brilliant color pigments and reaches a reflectivity value of 55% with future potential to reach 85%. The new technique differs from electronic-paper (e-paper) displays that use oils, dyes, or interference effects—such as electrowetting, electrophoretic, cholesteric liquid-crystal, or microelectromechanical systems (MEMS) interference-based displays —to achieve high-reflectivity (typically 50%) color.

(J. Heikenfeld et al., Nature Photonics online, DOI: 10.1038/NPHOTON.2009.68 (April 26, 2009).

Cross-section (left) and top views (right) of the display pixels are shown with no voltage applied (upper), confining the pigment to the cylindrical reservoir, and with an applied voltage (lower) that causes the pigment to disperse over the planar surface channel. (Courtesy of the University of Cincinnati)

Single pixels can be as small as tens of microns, although prototype devices were fabricated with pixel sizes on the order of hundreds of microns square.

Optical considerations To take full advantage of the brilliance of color pigments and to mimic their reflective and optical qualities as if they were inks printed on white paper, the design of the electrofluidic pixel structure uses an aluminum bottom plate as a high-performance reflector (with a reflectance of approximately 90%). Multilayer or composite reflectors could increase the reflectance to greater than 98%. In addition, the films on the top ITO substrate should be optimized in thickness and refractive index to minimize Fresnel reflections and loss.

Even without optimizing these two surfaces, reflectance values from prototype electrofluidic displays were 55% with pixel yields of greater than 98% for 30,000 fabricated pixels.

“We have formed a company to commercialize the technology called Gamma Dynamics (www.GammaDynamics.net), largely motivated by the factor that we envision some product manufacturing in the U.S.,” says Heikenfeld. “The impact of this technology goes far beyond displays. The same platform could be used to electronically shade windows, for tunable-color cell-phone cases, and even for adaptive camouflage.”

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e-Paper & e-Book - http://gammadynamics.net/wp-content/uploads/5-26-2010-Kens-SID-Paper.pdf Flexible Electrofluidic Displays Using Brilliantly Colored Pigments Kaichang Zhou,1 Kenneth A. Dean,1 and Jason Heikenfeld1,2 1Gamma Dynamics, Cincinnati, OH 45229 U.S.A. 2Novel Devices Laboratory, University of Cincinnati, Cincinnati, OH 45221 U.S.A.

Abstract We have developed a novel electrofluidic technology for displays that employs brilliantly colored, wellsaturated pigments in solution, modulated by electrowetting physics. We discuss the operating principles of the display, and demonstrate progress in key areas needed for realizing products, including fabrication on flexible substrates and performance from -28°C to 8 0°C.

- http://www.ece.uc.edu/devices/NDL_Research.html

The electrofluidic architecture is further unique from electrowetting displays in driving principles, device structure, potential for bistability, reduced parallax for multi-layer subtractive color pixels, in tight pixel confinement for rollable displays, and in use of water-dispersed pigments instead of oil soluble dyes. We chose the ‘electrofluidic’ nomenclature because the mechanism involves charge induced movement of liquids through microfluidic cavities. The basic electrofluidic structure contains several important geometrical features. First there is a reservoir, which will hold an aqueous pigment dispersion in less than 5-10% of the visible area. Secondly, there is a surface channel of 80-95% of the visible area, and which can receive the pigment dispersion from the reservoir when a suitable stimulus is applied. Third, there is a duct surrounding the device which enables counter-flow of a non-polar fluid (oil or gas) as the pigment dispersion leaves the Massimo Marrazzo - biodomotica.com 89

e-Paper & e-Books reservoir. It is important to note, that all of these features are inexpensively formed by a single photolithographic or microreplication step. Turning attention to the figure, several additional coatings and a top substrate are added. First, the surface channel is bound by two electrowetting plates consisting of an electrode and hydrophobic dielectric. The top electrowetting plate utilizes a transparent In2O3:SnO2 electrode (ITO) such that the surface channel is viewable by the naked eye. The bottom electrowetting plate utilizes a highly reflective electrode such as Aluminum. With the device structure described, we now begin a general discussion of device operation. With no applied voltage, a net Young-Laplace pressure causes the pigment dispersion to occupy the cavity that imparts a larger radius of curvature on the pigment dispersion.

Therefore at equilibrium, the pigment dispersion occupies the reservoir and is largely hidden from view. This is analogous to connecting two soap bubbles by a straw; the larger bubble has a larger radius of curvature, a lower Young-Laplace Pressure, and will therefore consume the smaller bubble. Next, as shown in the figure a voltage is applied between the two electrowetting plates and the pigment dispersion. This induces an electromechanical pressure that exceeds the net Young-Laplace pressure and the pigment dispersion is pulled into the surface channel. If the volume of the pigment dispersion is slightly greater than the volume of the surface channel, then the pigment will be simultaneously viewable in both the reservoir and the surface channel, and nearly the entire device area will exhibit the coloration of the pigment. If the voltage is removed the pigment dispersion rapidly (1â&#x20AC;&#x2122;s to 10â&#x20AC;&#x2122;s ms) recoils into the reservoir. Thus a switchable device is created that can hide the pigment, or reveal the pigment with visual brilliance that is similar to pigment printed on paper. Videos of this device in operation can be found on the videos page of this website.

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Electrochromic Technology (EC) - http://www.epapercentral.com/epaper-technologies-guide Electrochromism refers to the characteristic color change of a material associated with the materials’ reduction/oxidation state. Polyaniline and polyethylenedioxythiophene (PEDOT) are examples of electrochromic materials. An EC display element consists of at least two conductors, an electrochromic material and an electrolyte combined on a carrying substrate. The optical contrast is a result of the contrast between the white paper surface and the electrochromic materials switched to its colored state. These displays are fully flexible and the printed devices are less than 100 microns thick.

- http://www.ntera.com/monolith_construct.asp

□□□□□ - http://www.nims.go.jp/eng/news/press/2008/04/vk3rak000000195s.html

□□□□□ - http://www.answers.com/topic/electrochromic-device

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e-Paper & e-Books - http://www.ntera.com/technology/overview.php

NTERA's NanoChromics Ink Systems enable cost effective manufacturing of printed electronic displays on a variety of flexible substrate materials using industry standard printing techniques and equipment.

Advantages for Printed Electronics Applications -

All printed display solution World's thinnest display technology: less than 30 microns thick Low power: power consumed only during image refresh Low voltage: directly compatible with 1.5 V power systems Multiple colors: utilizes the natural colors of the electrochromic inks Single substrate architecture: enabling cost effective manufacturing Compatible with state-of-the-art Smart Card hot lamination processes

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Interferometric Modulator Display ( IMOD ) - http://www.epapercentral.com/epaper-technologies-guide An Interferometric modulator display (IMOD) uses a technology made up of subpixels which are actually miniature Fabry-Perot interferometers (etalons). An etalon, which is an optical term, reflects light at a specific wavelength and gives pure, bright colors like those in a butterfly’s wings. Moreover it consumes no power.

Microelectromechanical systems (MEMS) are used to switch the display on and off.

- http://www.mirasoldisplays.com/mems-displays/how-mirasol-works-mems-technology.php How Mirasol™ Displays Work: Micro-electro-mechanical Systems (MEMS) Drive IMOD Reflective Technology

- http://www.qualcomm.com/products_services/consumer_electronics/displays/mirasol/index.html Qualcomm’s mirasol display technology is based on a reflective technology called IMOD (Interferometric MODulation), with MEMS structures at its core.

This MEMS–based innovation is both bistable, meaning it is both extremely low power, and highly reflective, meaning the display itself can be seen even in direct sunlight.

By studying and mimicking nature’s processes and structures – a field of study called biomimetics – Qualcomm engineers have developed the nature-inspired mirasol display.

Video

- http://www.qualcomm.com/common/documents/white_papers/iMoD_Display_Overview.pdf Color Generation At the most basic level, an IMOD display is an optically resonant cavity similar to a Fabry-Perot etalon. The device consists of a self-supporting deformable reflective membrane and a thin-film stack (each of which acts as one mirror of an optically resonant cavity), both residing on a transparent substrate.

When ambient light hits the structure, it is reflected both off the top of the thin-film stack and off the reflective membrane. Depending on the height of the optical cavity, light of certain wavelengths reflecting off the membrane will be slightly out of phase with the light reflecting off the thin-film structure. Based on the phase difference, some wavelengths will constructively interfere, while others will destructively interfere as shown in Figure 1. As illustrated, the red wavelengths have a phase difference which leads to constructive interference, while the green and blue wavelengths have a phase difference which leads to destructive interference. As a result, the human eye will perceive a red color, as certain wavelengths will be amplified with respect to others. Color generation via interference is much more efficient in its use of light compared to traditional color filters and polarizers, which work on the principle of absorption and waste much of the light entering the display.

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IMOD Structure Showing Light Reflecting off the Thin-film Stack and Mirror Interfering to Produce Color The image on an IMOD display can switch between color and black by changing the membrane state. This is accomplished by applying a voltage to the thin-film stack, which is electrically conducting and is protected by an insulating layer. When a voltage is applied, electrostatic forces cause the membrane to collapse. The change in the optical cavity now results in constructive interference at ultraviolet wavelengths, which are not visible to the human eye. Hence, the image on the screen appears black.

A full-color display is assembled by spatially ordering IMOD elements reflecting in the red, green and blue wavelengths as shown in figure.

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- http://electronicdesign.com/article/components/mems-the-word-in-consumer-electronics19285/3.aspx

- http://en.wikipedia.org/wiki/Interferometric_modulator_display The Interferometric Modulator (iMoD) is a technology used in electronic displays that can create various colors through the interference of reflected light.

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e-Paper & e-Books - http://www.qualcomm.com/common/documents/white_papers/IMOD_Technology_Overview_new.pdf iMoD DISPLAY TECHNOLOGY The Building Blocks of Color An iMoD element is a simple, tiny (10-100 microns) micro-electro-mechanical system (MEMS) composed of two conductive plates: a thin film stack on a glass substrate, and a reflective membrane suspended below.

When a bias voltage holds the reflective membrane in the open state, the iMoD subpixel reflects a particular color. When the applied voltage pulls the reflective membrane into a collapsed state, all visible light is absorbed, making the element black.

To create a flat-panel display, many iMoD elements are grouped together as pixels or subpixels. Varying voltage across the displayâ&#x20AC;&#x2122;s elements creates rich, detailed imagery. The Efficiency of iMoD Memory An iMoD displayâ&#x20AC;&#x2122;s electro-mechanical memory, called hysteresis, allows it to maintain its state (open or collapsed). Once moved into the open/collapsed state, it stays there with very low quiescent current. This means the display acts as a highly power-efficient memory element, providing notable power savings over active matrix devices that constantly refresh.

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e-Paper & e-Book - http://www.qualcomm.com/products_services/consumer_electronics/displays/mirasol/ At CES 2010, Qualcomm was demonstrating a 5.7in (14.5cm) Mirasol display running at 1024 by 728 pixels.

A 10in (25.4cm) version is in the works. Qualcomm says they won’t be manufacturing eReaders themselves, but are working to supply OEM partners who want an alternative to e-ink and LCDs. Look for the Mirasolequipped products to begin shipping in late 2010.

□□□□□ - http://www.photonics.byu.edu/Fabry_Perot.phtml

What is a Fabry-Perot cavity?

Fabry-Perot cavities are small devices about a millionth of an inch wide. They are built out of small, halfsilvered mirrors. Light entering them gets trapped inside.

Once inside a Fabry-Perot cavity, certain wavelengths of light are positively reinforced, while most wavelengths destructively interfere with each other.

In the illustration below, red light is passed, while other wavelengths are blocked.

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e-Paper & e-Books Why are Fabry-Perot cavities useful?

Fabry-Perot cavities can be used to isolate a single wavelength of light. Because they isolate only one wavelength of light, Fabry-Perot cavities are instrumental in making laser light, wavelength filters, or calibration instruments.

Fabry-Perot cavities can be built to pass almost any wavelength of light. Some Fabry-Perot cavities can be controlled by an electronic circuit to block / pass a variable wavelength.

□□□□□ - http://spie.org/x8775.xml

Plastic film finds a new role in micro-optics Hiroshi Toshiyoshi Plastic sheeting has the potential to extend the advantages of microelectromechanical systems technology to large-area devices such as image displays.

25 May 2006, SPIE Newsroom. DOI: 10.1117/2.1200604.0184

The cross-sectional structure of the MEMS color pixel array is based on an electrostatically controlled FabryPerot interferometer.

Shown is the flexible Fabry-Perot interferometer color pixel array.

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Photonic Crystal Technology (P-INK) - http://www.epapercentral.com/epaper-technologies-guide Photonic crystals, which are nanostructures arranged in a regular pattern. Changing the pattern causes a change in the color of light that the crystals reflect. Artificial opals are similar to those occurring naturally, with one exceptionâ&#x20AC;&#x201D;artificial opals can be stimulated electrically to change color. These opals can then be integrated into a layer of millions of tiny silica spheres, which are embedded into an electroactive polymer.

The layer is then sandwiched between transparent electrodes. When current is applied, it causes the polymer to swell, which in turn changes the spacing of the crystals. If this movement is controlled, the crystals can be maneuvered to produce the entire light spectrum. Such layers can then be arranged into a display similar to a traditional LCD screen. The advantage of this technology is that the pixels can be individually tuned to any color, and the color is purported to be brighter and more intense.

- http://technologyreview.com/computing/19337/

Crystal light: Photonic crystals made out of silica beads (shown as gray balls) measuring 200 nanometers across are embedded in a spongy electroactive polymer and sandwiched between transparent electrodes.

When a voltage is applied, an electrolyte fluid is drawn into the polymer composite, causing it to swell (shown as yellow in the middle image). This alters the spacing of the crystals, affecting which wavelengths of light they reflect. When the spacing is carefully controlled, the pixel can be made to reflect any color in the visible spectrum. Credit: Nature Photonics

- http://thefutureofthings.com/news/1020/p-ink-technology-under-development.html

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e-Paper & e-Books P-Ink and Elast-Ink from lab to market

- http://www.opalux.com/index.php?page=eact Opalux's lead technology in this cluster is "P-Ink" (short for Photonic Ink). P-Ink combines the Photonic Crystal structure with electrically active polymer materials. These respond to voltage and current and cause precise and predetermined changes to the Photonic Crystal structure, which in turn shifts the reflected color

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O LE D - http://www.sharpsma.com/Page.aspx/americas/en/b3fad008-bf63-4e66-ab68-7a52cae8fa1e OLED Organic Light Emitting Diode (OLED) technology was invented in the 1980's. There were two types that emerged. One was Eastman Kodak's molecular type (or thin film) and the other was the polymer type (or thick film). The thick film technology was mostly developed at the University of Cambridge which spawned Cambridge Display Technologies (CDT).

The key point to understand about OLEDs is that just like an LCD, they must be used in conjunction with an active matrix array except for the very simplest character type displays. To get sufficient current to drive an OLED array, one must use a low temperature polysilicon process. OLEDs are not very efficient, so when multiplexed, they have to be driven with relatively high currents to get an adequate amount of light.

Positive OLED Characteristics: · ·

Since it is a light emitter, it creates light that is Lambertian so it can be seen uniformly at all angles and gives a very pleasing effect.

The biggest strength of OLEDs is that they do not require a backlight and can be made thinner than any other technology used today. A 2 mm thick OLED is a reality today where the thinnest LCD is 3 mm.

Negative OLED Characteristics: ·

· ·

Dynamic display efficiency. While you can write a few lines of static text with great efficiency, video requires more power than an LCD. OLEDs are more efficient for small graphics or text because they only consume power in the area where they are addressed.

To date, the reliability has not come up to the levels of LCDs. It is particularly difficult to drive the blue colors where the luminance efficiency is very low. As a consequence, the lifetime is reduced, and burn-in is also an issue.

□□□□□ - http://www.phonescoop.com/glossary/term.php?gid=101 OLED (Organic Light-Emitting Diode) Also known as LEP (Light-Emitting Polymer), OLED is a next-generation display technology that consists of small dots of organic polymer that emit light when charged with electricity.

OLED displays come in single-color, multi-color, and full-color varieties.

Compared to color LCDs, color OLED displays... · are thinner · are lighter weight · are brighter · have better viewing angles · use less power · are simpler and cheaper to manufacture · have better response time for video and animation For these reasons, OLEDs are expected to replace LCDs for color displays in phones and other small, portable devices.

One drawback of OLED technology is that, since it only emits and does not reflect light, it can be difficult to see in very bright light, such as direct sunlight.

OLED display modules used in secondary displays are often of a simple type using passive-matrix technology. Better OLED display modules used as primary phone displays are active-matrix, sometimes referred to as AMOLED. AMOLED is one of two types of OLED display. The AM (active-matrix) type has a transistor next to each pixel, allowing faster response time. This makes AMOLED suitable for displaying video, and is therefore the most common type of OLED display for a main phone display.

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e-Paper & e-Books - http://electronics.howstuffworks.com/oled.htm OLED Components Like an LED, an OLED is a solid-state semiconductor device that is 100 to 500 nanometers thick or about 200 times smaller than a human hair. OLEDs can have either two layers or three layers of organic material; in the latter design, the third layer helps transport electrons from the cathode to the emissive layer. In this article, we'll be focusing on the two-layer design.

An OLED consists of the following parts: · Substrate (clear plastic, glass, foil) - The substrate supports the OLED. · Anode (transparent) - The anode removes electrons (adds electron "holes") when a current flows through the device. · Organic layers - These layers are made of organic molecules or polymers. · Conducting layer - This layer is made of organic plastic molecules that transport "holes" from the anode. One conducting polymer used in OLEDs is polyaniline. · Emissive layer - This layer is made of organic plastic molecules (different ones from the conducting layer) that transport electrons from the cathode; this is where light is made. One polymer used in the emissive layer is polyfluorene. · Cathode (may or may not be transparent depending on the type of OLED) - The cathode injects electrons when a current flows through the device Types of OLEDs: Passive and Active Matrix There are several types of OLEDs: · Passive-matrix OLED · Active-matrix OLED · Transparent OLED · Top-emitting OLED · Foldable OLED · White OLED Each type has different uses. In the following sections, we'll discuss each type of OLED. Let's start with passive-matrix and active-matrix OLEDs. Passive-matrix OLED (PMOLED) PMOLEDs have strips of cathode, organic layers and strips of anode. The anode strips are arranged perpendicular to the cathode strips. The intersections of the cathode and anode make up the pixels where light is emitted. External circuitry applies current to selected strips of anode and cathode, determining which pixels get turned on and which pixels remain off. Again, the brightness of each pixel is proportional to the amount of applied current.

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PMOLEDs are easy to make, but they consume more power than other types of OLED, mainly due to the power needed for the external circuitry. PMOLEDs are most efficient for text and icons and are best suited for small screens (2- to 3-inch diagonal) such as those you find in cell phones, PDAs and MP3 players. Even with the external circuitry, passive-matrix OLEDs consume less battery power than the LCDs that currently power these devices.

Active-matrix OLED (AMOLED) AMOLEDs have full layers of cathode, organic molecules and anode, but the anode layer overlays a thin film transistor (TFT) array that forms a matrix. The TFT array itself is the circuitry that determines which pixels get turned on to form an image.

AMOLEDs consume less power than PMOLEDs because the TFT array requires less power than external circuitry, so they are efficient for large displays. AMOLEDs also have faster refresh rates suitable for video.

The best uses for AMOLEDs are computer monitors, large-screen TVs and electronic signs or billboards.

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□□□□□ - http://www.oled-info.com/oled-technology How do OLEDs work?

An OLED is made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted. Here's Kodak's description of OLEDs "OLED displays stack up several thin layers of materials. They operate on the attraction between positively and negatively charged particles. When voltage is applied, one layer becomes negatively charged relative to another transparent layer. As energy passes from the negatively charged (cathode) layer to the other (anode) layer, it stimulates organic material between the two, which emits light visible through an outermost layer of glass."

AMOLED vs PMOLED These terms relate to the driving method of the OLED display. With Passive-Matrix (PMOLED), one controls the display by switching a certain row and column - in effect lighting the pixel at the intersection. The pixels are turned on and off quickly, and the sequence creates the image. With Active-Matrix (AMOLEDs)one controls each pixel directly. Passive-Matrix OLEDs are easy and cheap to make, but has a high power consumption and only allow for small sized displays (up to 3", typically). Making larger and more efficient displays require the use of AMOLEDs – but these are more expansive to make.

So if you're looking for a TV, it'll probably be an AMOLED TV. PMOLEDs are used in mp3 players, secondary displays on cell phones, etc.

Small molecules vs Polymer-based OLEDs OLED materials can be divided into small- and large- molecules. 'Small Molecules' OLEDs are more common today, with most displays using those kind of materials. Large Molecules (also called Polymerbased OLEDs, or P-OLEDs) are lagging behind in lifetime and efficiency specs. P-OLEDs might be easier to make, though, because they are more easily adapted for printing. Indeed, one can 'ink-jet-print' an OLED, which is a great way to make them.

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e-Paper & e-Book Fluorescent vs Phosphorescent OLEDs OLEDs can also be classified based on another property of the material â&#x20AC;&#x201C; whether it is fluorescent or phosphorescent (PHOLEDs). Originally fluorescent OLEDs were used, but PHOLEDs promise to deliver much more efficient displays.

The major company behind PHOLEDs is Universal-Display. They have recently stated that "virtually all" AMOLEDs use their technology - although only their red material is currently used (the other colors are fluorescent).

- http://www.oled-info.com/amoled AMOLED OLEDs are made from organic (carbon based) materials that emit light when electricity is run through them.

OLEDs can be used to create displays - and these are bright and efficient with a fast response time and a wide viewing angle. OLED display can be made very thin (the thinnest prototype is 50 microns...) and even transparent or flexible.

- http://www.oled-info.com/pmoled-vs-amoled-whats-difference PMOLED vs AMOLED - what's the difference?

OLED is a new technology for thin, efficient and bright displays. There are two types of OLEDs: PassiveMatrix (PMOLED) and Active-Matrix. This article explains the difference in both the technology and the applications.

- http://komar.cs.stthomas.edu/qm425/01s/Tollefsrud2.htm OLED structure The basic OLED cell structure consists of a stack of thin organic layers sandwiched between a transparent anode and a metallic cathode. The organic layers comprise a hole-injection layer, a hole-transport layer, an emissive layer, and an electron-transport layer. When an appropriate voltage (typically between 2 and 10 volts) is applied to the cell, the injected positive and negative charges recombine in the emissive layer to produce light (electro luminescence). The structure of the organic layers and the choice of anode and cathode are designed to maximize the recombination process in the emissive layer, thus maximizing the light output from the OLED device.

By: Patrick A. Tollefsrud

- http://en.wikipedia.org/wiki/Organic_light-emitting_diode Organic light-emitting diode An organic light-emitting diode (OLED), also light emitting polymer (LEP) and organic electro-luminescence (OEL), is any light-emitting diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process.

The resulting matrix of pixels can emit light of different colors.

Such systems can be used in television screens, computer displays, portable system screens such as PDA's, advertising, information and indication. OLEDs can also be used in light sources for general space illumination, and large-area light-emitting elements. OLEDs typically emit less light per area than inorganic solid-state based LEDs which are usually designed for use as point-light sources.

A significant benefit of OLED displays over traditional liquid crystal displays (LCDs) is that OLEDs do not require a backlight to function. Thus they draw far less power and, when powered from a battery, can operate longer on the same charge. Because there is no need for a backlight, an OLED display can be much thinner than an LCD panel. OLED-based display devices also can be more effectively manufactured than LCDs and plasma displays. However, degradation of OLED materials has limited their use.

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e-Paper & e-Books http://printedelectronics.idtechex.com/printedelectronicsworld/articles/vitex_and_novaled_will_cooperate_on_oled_thin_film_encapsulati on_00001050.asp

Vitex and Novaled will cooperate on OLED thin film encapsulation OLED displays must be protected from water and moisture, which can react with both organic and inorganic active layers degrading performance and display appearance.

Vitex has developed an ideal solution to resolve moisture and oxygen sensitivity problems in the production of OLED displays and other sensitive electronic devices. Specifically, Vitex is applying its proprietary technology to create a moisture and oxygen barrier that is equivalent to a sheet of glass. The resulting multilayer barrier can be applied to flexible plastic film or over a finished display. Using its proprietary technology, Vitex has developed Barix_ encapsulation and Flexible Glass Engineered Substrate.

Copyright © 2008 IDTechEx Ltd.

- http://www.cdtltd.co.uk/technology/43.asp The term 'nanotechnology' is widely used today, and P-OLED technology can certainly be thought of as an example. The total thickness of all layers in a P-OLED display device can be less than 500nm, so that in effect, the thickness of a display is similar to the thickness of the substrates (usually glass) that form the top and bottom of the device.

The structure of a basic P-OLED display device can be extremely simple, consisting of a sandwich containing: · A transparent conducting electrode with a large work function (Anode). Indium tin oxide (ITO) is commonly used, coated on a substrate · A conducting polymer layer which transports and injects holes into the active layers (Hole Injection / Transport Layer) · A thin organic interlayer material sometimes referred to "primer layer" developed by CDT to improve efficiency and lifetime · A thin light emitting polymer (LEP) layer less than 100nm thick (Emissive Layer) · A metallic electrode with a low work function, such as a barium/aluminium bi-layer (Cathode)

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e-Paper & e-Book - http://www.cdtltd.co.uk/technology/200.asp The ability of P-OLEDs to be fabricated on flexible substrates opens up fascinating possibilities for formable or even fully flexible displays.

Photo courtesy of Dai Nippon Printing Š Copyright 2008 Cambridge Display Technology Ltd.

Eye catching packaging with changing information content at the point of sale would give many brand owners a valuable competitive edge.

Photo courtesy of Dai Nippon Printing Š Copyright 2008 Cambridge Display Technology Ltd.

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Transparent OLED - http://www.universaldisplay.com/toled.php Transparent OLEDs have only transparent components (substrate, cathode and anode) and, when turned off, are up to 85 percent as transparent as their substrate. When a transparent OLED display is turned on, it allows light to pass in both directions. A transparent OLED display can be either active- or passive-matrix.

- http://electronics.howstuffworks.com/oled.htm

- http://www.universaldisplay.com/default.asp?contentID=584 Universal Display’s TOLED® technology is based on a proprietary top contact, or cathode, that is optically transparent. In a typical OLED, the bottom contact, or anode, consists of a transparent metal oxide film and the top contact consists of a reflective metal. As a result, when light is generated by the OLED, it emits through the bottom transparent surface. TOLEDs use an optically transparent top cathode, meaning both top and bottom contacts allow light transmission.

TOLED technology enables three key features that have the potential to create a host of new product opportunities.

For applications as diverse as architectural windows for home entertainment, retail advertising and illumination, to navigation/warning displays on windshields and heads-up helmet faceshields, TOLED™ technology can pave the way.

Transparency: Capable of 70% to 85% transparency when turned off, TOLED pixels are nearly as clear as the glass or plastic substrate on which they are built. When used in an active-matrix OLED configuration, the effective transmission of the TOLED may, however, be somewhat reduced depending on the display resolution of the display and TFT design.

Bi-directional emission: Typically, the light generated by the TOLED emits from both surfaces. View a video.

Enhancement films and other optical treatments may be used to direct more of the light in one direction than the other.

Performance: TOLEDs also offer excellent opto-electronic performance properties, i.e., spectral color emission, luminous efficiency and lifetime – that compare well to those for bottom-emission OLEDs.

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e-Paper & e-Book - http://www.oled-display.net/how-works-a-transparent-oled How works a transparent OLED? If you've seen the movie "Minority Report" and marvelled at the transparent computer screens used by Tom Cruise, you'll appreciate what German researchers have concocted in their labs: entirely transparent OLED (organic light emitting diode) pixels.

The researchers, located at the Technical University of Braunschweig, are claiming the development to be a world's first.

Their approach is to use transparent TFTs (thin-film transistors) made of a 100-nanometer-thick layer of zinctin-oxide, which transmits more than 90 percent of visible light. Such transistors are more often made of silicon, which is used for LCDs (liquid crystal displays) but is highly absorptive in the visible part of the spectrum.

In the transparent displays, the TFTs and the OLED pixels are positioned next to each other. The OLED pixel can be placed on top of the TFT driver circuit without interference.

In addition, because the TFT layers are thin, they can be deposited on large areas with conventional techniques, and because these techniques can be performed at temperatures below 200 degrees Celsius, cheap, flexible plastic substrates can be used.

In the devices developed by the researchers, the brightness of the OLED pixels varied from 0 to 700 candelas per square meter by changing the voltage of the driving TFTs. By comparison, typical computer screens today reach a brightness of approximately 300 candelas per square meter.

Transparent OLEDs have only transparent components (substrate, cathode and anode) and, when turned off, are up to 85 percent as transparent as their substrate. When a transparent OLED display is turned on, it allows light to pass in both directions. A transparent OLED display can be either active- or passive-matrix.

This technology can be used for heads-up displays. Top-emitting OLEDs have a substrate that is either opaque or reflective. They are best suited to active-matrix design. Manufacturers may use top-emitting OLED displays in smart cards.

CES-2010 World first Notebook with 14 inch transparent OLED Display Samsung Mobile Display showed the world first and largest transparent OLED panel prototpye at CES-2010.

Samsung SDI Co Ltd showcased the "Window Display," an OLED panel with a transparent of 30%. The company used four 12.1-inch Window Displays to make a "window".The resolution of the panel is 840 Ă&#x2014;504, and its luminance is 200cd/m2. The color reproduction range is 100% of the NTSC standard. The response time is 0.01ms.

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e-Paper & e-Books - http://www.engadget.com/2010/01/07/samsungs-14-inch-transparent-oled-laptop-video/ Samsung's 14-inch transparent OLED laptop

By Joseph L. Flatley posted Jan 7th 2010

Video

If you thought the XPERIA Pureness was wild with its meager 1.8-inch transparent screen, wait'll you get a hold of Samsung Mobile Display's prototype 14-inch notebook -- complete with what's being touted as the world's first and largest transparent OLED prototype. When the thing is off, the panel is up to 40 percent transparent (as opposed to the industry average of below twenty-five percent).

- http://forum.dailymobile.se/index.php?topic=34521.0 FPD 2010:Transparent AMOLED Display & Flexible AMOLED Display Samsung did it. While most of the company struggling to bring Amoled Display on their Mobile Devices, Samsung gone more further and showed 4.3-inch and 14-inch Transparent AMOLED Display. The 4.3-inch Flexible Display demonstrating a great capability to flow into smooth and attractive curves on a gorgeous looking Device. On the Other hand, 14-inch transparent AMOLED display was showcased in a prototype 14inch notebook.

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e-Paper & e-Book Transparent AMOLED display

A transparent AMOLED display was showcased in a prototype 14-inch notebook. Worked as expected, though I would have like to know if it could operate normally without transparency. For the size, the resolution was quite low at 960 x 540 pixels (78 PPI) and 250 cd/m2 brightness.

□□□□□ - http://www.oled-display.net/neoview-kolon-show-transparent-oled-displays-at-filmtech Neoview-Kolon show Transparent OLED Displays at Filmtech April, 2010

NeoView Kolon showcased at the FilmTech Transparent OLED Displays.

One of the TOLED Displays is focused to the automotive industry. The Transmittance of thiw T-OLED is Max 77 %.

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Neoview Kolon shows also 2.4 inch Transparent AMOLED Display for head mounted displays.

This TOLED features: • Display Format: Dot Matrix • Display Color: 16 Million • Transmittance: Maximal 62 percent

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e-Paper & e-Book - http://laptopreviewshop.com/tdk-joins-the-transparent-oled-fight.html TDK joins the transparent OLED fight Mircea / October 2010

TDK makes its entrance on the transparent OLED market with 2-inch passive matrix screen with a humble QVGA (320 x 240) resolution. Sure, no eye-popping specs here, but a claimed 50 percent transmittance which means that half of what's behind the screen can be seen through it, knocks out both Samsung and LG.

TDK also presented another 3.5 inch flexible OLED screen which is as thin as 0.3 mm. It's made using a resin substrate and squeezes only 256 x 54 pixels at the moment, but TDK plans to take both technologies Massimo Marrazzo - biodomotica.com 113

e-Paper & e-Books step by step into the realm of awesomeness. Be sure to keep your eye on these if you find yourself at CEATEC 2010, and who knows, maybe we'll even hear about a flexible transparent OLED screen soon if these technologies will merge together. * CEATEC: Combined Exhibition of Advanced Technologies is an annual trade show in Japan.

□□□□□ - http://www.crunchgear.com/2010/10/05/ceatec-2010-eyes-on-with-tdks-bendable-and-transparent-oleds-video/ TDK's two passive matrix mini OLED panels

by Serkan Toto on October 2010

A pleasant surprise at this year’s CEATEC: TDK's two passive matrix mini OLED panels, one of which is transparent and the other bendable (like the one Sony showed earlier this year). What's cool is that both prototypes are showcased as black-and-white and color models.

You can see both displays in action in the videos I took at the exhibition below.

The flexible type is just 0.3mm thin and sized at 3.5 inches. Apparently, TDK plans to start mass-producing this panel as early next year. Its picture quality wasn't really as high as you'd want it to be, but there is still time for improvements.

The panel with the bigger wow-factor, the see-through type, was really cool. It has a transmittance of about 50% and features QVGA resolution — which is OK, at a screen size of about 2 inches. I want one, but I am not sure why exactly screens (of any size) would have to be transparent.

Video on TDK's displays

- http://www.engadget.com/2010/10/05/tdks-see-through-and-curved-oled-display-eyes-on/ TDK's see-through and curved OLED display eyes-on

By Chris Ziegler - Oct 2010

Engadget.com - By Chris Ziegler

Remember the Sony Ericsson Xperia Pureness? At a list price of $1,000, it'd be hard to forget -- but with a monochrome see-through display, the whole transparency thing was little more than a novelty on a phone that served little practical purpose. TDK might have the solution with its new transparent QVGA OLEDs, available now to manufacturers in monochrome and in a lovely color variant by the end of the year. At two inches, they offer 200ppi pixel density and are more secure than you might think: the light only shines in one direction, so you actually can't see any data from the back even though you can still see through the display.

At a glance, the display's didn't seem as vibrant as the best AMOLEDs on the market, but then again, these are passive matrix -- and you can really tell in our videos after the break where the refresh scans stand out.

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A M OL E D - http://www.densitron.co.uk/AMOLED.php What is AMOLED? Active Matrix Organic Light-Emitting Diode (AMOLED) displays combine, the benefits of Organic Lightemitting technology, i.e brighter and clearer, richer images with those of an active matrix technology (as used on TFTs).

TFT vs OLED The two diagrams below illustrate that backlighting is the main fundamental difference between the structure of an OLED and that of a TFT. OLED display modules, employing an emissive technology, and therefore naturally do not require any backlighting; transmissive and transflective TFT’s always will.

The elements that would normally be associated with backlighting in a TFT module are shown in the OLED structural diagram as transparent elements; as a reminder of which elements have been omitted in comparison to TFT’s. This lack of backlighting elements is what leads to OLED’s being thinner than TFT’s AMOLED With as much as 25x better sunlight readability than (transmissive) TFT’s, and response times of microseconds rather than milliseconds, these displays offer excellent colour saturation, high contrast and fast response. With very low power consumption (typically 30% – 50%) compared to poly-silicon TFT’s, they are perfect for use in small devices, especially those involving video playback.

Low power consumption –20ºC to 60ºC operating temperature Very fast response time Very high contrast ratio Sunlight readable Unlimited viewing angle

- http://www.oled-display.net/what-is-amoled What is AMOLED?

By Erich Strasser

AMOLED means Active Matrix Organic light emitting diode Active matrix (AM) OLED displays stack cathode, organic, and anode layers on top of another layer - or substrate - that contains circuitry. The pixels are defined by the deposition of the organic material in a continuous, discrete "dot" pattern. Each pixel is activated directly: A corresponding circuit delivers voltage to the cathode and anode materials, stimulating the middle organic layer. AM OLED pixels turn on and off more than three times faster than the speed of conventional motion picture film - making these displays ideal for fluid, full-motion video.

Two primary TFT backplane technologies, poly-Silicon (poly-Si) and amorphous-Silicon (a-Si) are used today in AMOLEDs. Passive-Matrix Structure ------------------------ Active Matrix Structure

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Why is AMOLED the future?

High Perceived Luminance Perceived luminance is 1.5 times higher than that of conventional lcd display.

Contrast ratio The contrast of an AMOLED is unbelievable it offers clear images and readability in any environment.

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True Colours High color gamut and no color shift by viewing angle and/or gray scales

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e-Paper & e-Books - http://en.wikipedia.org/wiki/Active-matrix_OLED Active-matrix OLED (Active-matrix organic light-emitting diode or AMOLED) An active matrix OLED display consists of a matrix of OLED pixels that generate light upon electrical activation that have been deposited or integrated onto a thin film transistor (TFT) array, which functions as a series of switches to control the current flowing to each individual pixel.

Typically, this continuous current flow is controlled by at least two TFTs at each pixel, one to start and stop the charging of a storage capacitor and the second to provide a voltage source at the level needed to create a constant current to the pixel and eliminating need for the very high currents required for passive matrix OLED operation.

TFT backplane technology is crucial in the fabrication of AMOLED displays. Two primary TFT backplane technologies, namely polycrystalline silicon (poly-Si) and amorphous silicon (a-Si), are used today in AMOLEDs. These technologies offer the potential for fabricating the active matrix backplanes at low temperatures (below 150°C) directly onto flexible p lastic substrates for producing flexible AMOLED displays.

Advantages Active-matrix OLED displays provide higher refresh rates than their passive-matrix OLED counterparts, and they consume significantly less power. This advantage makes active-matrix OLEDs well suited for portable electronics, where power consumption is critical to battery life.

The amount of power the display consumes varies significantly depending on the color and brightness shown. As an example, one commercial QVGA OLED display consumes 3 watts while showing black text on a white background, but only 0.7 watts showing white text on a black background.

Disadvantages AMOLED displays may be difficult to view in direct sunlight compared to LCD displays. Samsung's Super AMOLED technology addresses this issue by reducing the size of gaps between layers of the screen.

The organic materials used in AMOLED displays are prone to degradation over a period of time. However, technology has been developed to compensate for material degradation.

Schematic of an active matrix OLED display â&#x20AC;&#x201C; by Len Hallam - Wikipedia

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S u p e r - A M O LE D - http://www.engadget.com/2010/03/09/samsung-super-amoled-explained-in-pretty-moving-pictures-video/ Samsung Super AMOLED explained in pretty moving pictures (video)

By Thomas Ricker Mar 2010

Using "super" to describe your new display technology just begs for criticism. Especially when the word is affixed to a handheld display technology as notoriously difficult (if near impossible) to see in direct sunlight as OLED. Fortunately, Samsung's Super AMOLED appears to have licked the outdoor readability issue while bettering the features that made us fall in love with AMOLEDs in the first place. First off, it's thinner since the touch sensors are now integrated into the display; colors are more vivid due to the removal of the obfuscating touch sensor layer that sits on top of TFT LCD and traditional AMOLED touchscreen displays; and even the viewing angle has been improved.

Video

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Q D LE D - http://en.wikipedia.org/wiki/Quantum_dot_display Quantum dot display Quantum dots (QD) or semiconductor nanocrystals are a form of light emitting technology and consist of nano-scale crystals that can provide an alternative for applications such as display technology. This display technology differs from cathode ray tubes (CRTs), liquid crystal displays (LCDs), but it is similar to organic light-emitting diode (OLED) displays, in that light is supplied on demand, which enables new, more efficient displays, which is enabling mobile devices with longer battery lives. Unlike inorganic semiconductor based LEDs, organic electroluminescent devices can be deposited over larger areas and on flexible or non-planar substrates. Large area display or general illumination devices have been fashioned from these molecules and have begun their entry into the market. However, the light emitting organic molecules tend to degrade and are particularly sensitive to humidity and oxidation. Quantum dots incorporate the best aspects of both organic light emitters and inorganic light emitters. With many promising advantages, QD LED or QLED is considered as a next generation display technology. QDs can be incorporated into a new generation of applications such as flat-panel TV screens, digital cameras, mobile phones, personal gaming equipment and PDAs.

Schematic of a quantum dot light-emitting diode â&#x20AC;&#x201C; a light-emitting sandwich filling.

The structure of QD-LED is similar to basic design of OLED. The major difference is that the light emitting centers are cadmium selenide (CdSe) nanocrystals, or quantum dots. A layer of cadmium-selenium quantum dots is sandwiched between layers of electron-transporting and hole-transporting organic materials. An applied electric field causes electrons and holes to move into the quantum dot layer, where they are captured in the quantum dot and recombine, emitting photons.

Pros 1. Color range: Nanocrystal displays should be able to yield a greater portion of the visible spectrum than current technologies. As shown in the diagram, QD Vision calculates as much as 30% more of the visible spectrum would be available using QDs in a QD-LED vs. a CRT TV. 2. Low power consumption: QD Vision estimates its nanocrystal displays could use 30 to 50% less electrical power than an LCD, in large part because nanocrystal displays don't need a backlight.

3. Vibrant colors: Nanocrystal displays would yield more purity in colors than other types of display technologies. Some display technologies, such as LCDs, canâ&#x20AC;&#x2122;t create a pure red, green, or blue for the display; instead, they need to add a few other colors to those three to display pure colors.

Quantum dots, on the other hand, create pure red, green, and blue to create all other colors.

2 4. Brightness: 50~100 times brighter than CRT and LCD displays ~40,000 cd/m 5. Color purity: the color produced by QDs provides for an improved viewing experience for the end user 6. Added flexibility: QDs are soluble in both aqueous and non-aqueous solvents, which provides for printable and flexible displays of all sizes, including large area TVs 7. Improved lifetime: QDs are inorganic, which can give the potential for improved lifetimes when compared to alternative OLED technologies. However, since many parts of QD-LED are made of organic materials, further development is required to improve the functional lifetime.

Cons Less saturated blue: Blue quantum dots are difficult to manufacture due to the timing control during the reaction. A blue quantum dot is just slightly above the minimum size, where red to green can be easily 120 Massimo Marrazzo - biodomotica.com

e-Paper & e-Book obtained. Also, human eyes need 50x brighter blue than green in order for the two colors to be perceived as being the same luminosity.

Commercialization of quantum dot display is yet to come. Compared to LCD and OLED, the manufacturing cost of QD-LED is relatively high and development of novel and more cost-efficient fabrication process is desired in future

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- http://www.qdvision.com/qleds-the-future

Quantum dot light emitting diodes (QLEDs) represent an advanced electroluminescent technology currently in the development stage that will lead to the next generation of electronic displays and solid-state lighting applications. QLEDs are a reliable, energy efficient, tunable color solution for display and lighting applications that reduce manufacturing costs, while employing ultra-thin, transparent or flexible materials.

Still in the early stages of commercialization, QLEDs can already be used in certain defense and security related products that require precision color solutions in an ultra-slim form factor, including monochrome visible and infrared displays, and lighting devices for machine and night vision applications.

QLEDs bring numerous benefits to the solid state lighting and display markets, including: • Pure color -- Will deliver 30-40% luminance efficiency advantage over organic light emitting diodes (OLEDs) at the same color point.

• Low power consumption -- QLEDs have the potential to be more than twice as power efficient as OLEDs at the same color purity.

• Low-cost manufacture -- The ability to print large-area QLEDs on ultra-thin flexible substrates will reduce luminaire manufacturing cost.

• Ultrathin, transparent, flexible form factors -- QLEDs will enable designers to develop new display and lighting forms not possible with existing technologies.

The unique combination of extraordinary color, high efficiency, form factor and solution-processability makes QD Vision’s QLEDs a breakthrough electroluminescent technology for next generation electronic displays and solid-state lighting applications.

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- http://androidspin.com/2010/12/01/lg-partners-with-qd-vision-to-bring-quantum-dot-led-screens-to-the-mobile-world/ LG Partners with QD Vision to Bring Quantum Dot LED Screens to the Mobile World

By Stormy Beach on December 1, 2010

As of yesterday, LG and QD Vision announced their partnership to move forward with their QLED screen technology. This latest venture is guaranteed to produce richer color and increase screen brightness while reducing power consumption compared to anything else on the market. The press release states that these new screens will be flexible, much like the latest screens Samsung and other manufacturers have been working on. Just reading the first paragraph of the release make me tingle all over.

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e-Paper & e-Books - http://www.gottabemobile.com/2010/12/01/quantum-dot-led-technology-to-succeed-oled/ Quantum-Dot LED Technology to Succeed OLED Chuong Nguyen | Dec 01, 2010

While Samsung is looking to replace IPS LCD screens with its own Super PLS LCD screens, LG Display is tackling the OLED display technology along with QD Vision. With QD Vision’s design, LG Display is looking to produce quantum-dot LED screens, also known as QLED displays, which is a nanotechnology display that offers better performance than OLED display. Some of the benefits of QLED display include better brightness, more vibrant colors, and increased energy efficiency, the latter being an important component on mobiles such as smartphones and tablets while the former two factors are critical for outdoors operation under direct sunlight.

Each quantum dot is said to carry the same stability and reliability as LCD screen technology while at the same time the simplified manufacturing process of QLED panels should mean that the displays will cost less than traditional OLED screens right now.

QLED screens are said to be twice as power efficient as OLED screens, and offer 30 to 40% improved brightness.

OLED screens, and its variant AMOLED screens, are commonly found on smartphones such as the HTC Desire and Nokia’s touchscreen phones. Samsung had improved upon AMOLED displays, calling their technology Super AMOLED, and have used that in the company’s Galaxy S smartphones. In 2010, due to the increased demand for AMOLED displays, there was an AMOLED shortage that prompted manufacturers such as HTC to switch their devices over to Super LCD screen technologies mid-cycle. Devices like the HTC Desire that started production with an AMOLED display were later outfitted with Super LCD displays as the AMOLED shortage grew.

At this time, no information was given about when LG hopes to mass produce the QLED displays with QD Vision.

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Flexible Display - http://www.crunchgear.com/2010/05/26/video-sonys-new-super-thin-oled-display-wraps-around-a-pencil/ Sony's new, super-thin OLED display wraps around a pencil

by Serkan Toto on May, 2010

OLEDs, which are said to lead the next wave of innovation in the TV space (after back-lit LCDs and 3D displays), come with plenty of advantages: they produce gorgeous images, they are self-luminous, light, and they’re flexible – very flexible. Case in point: a super-thin, Sony-made 4.1-inch OLED that actually wraps around a pencil, shown today in Japan.

The display is just 80µm thick, offers 432 x 240 resolution (121 ppi), a contrast ratio of around 1,000:1, and produces 100 cd/m2 brightness. Sony says the OLED can be wrapped around a pencil with just a 4mm radius. And the OLED can actually continue to display images and video while being rolled up, which is (according to Sony) a world’s first.

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e-Paper & e-Books - http://www.gizmag.com/sony-rollable-otft-driven-oled-display/15226/ Sony's rollable OTFT-driven OLED display

By Darren Quick - May 2010

The miniaturization of electronic components has seen mobile devices shrink to the point where screen size is a major limiting factor. That could be set to change with Sony announcing it has developed a super-flexible full color OLED display which can be repeatedly wrapped around a thin cylinder while still producing moving images. Could we soon see mobile phones with pencil form factors and roll out displays?

The new display was possible thanks to the development of integration technologies of Organic Thin-Film Transistors (OTFTs) and OLEDs on an ultra-thin 20-micrometer thick flexible substrate. A flexible on-panel gate-driver circuit with OTFTs and soft organic insulators allowed Sony to get rid of the conventional rigid driver integrated circuit (IC) chips that would impede the rolling up of a display.

By combining these technologies, Sony was able to demonstrate the world’s first OLED panel which is capable of producing moving images while being repeatedly rolled-up and unrolled around a cylinder with a radius of 4mm. Even after 1000 cycles of repeatedly rolling-up and stretching the display there was no clear degradation in the display’s ability to reproduce moving images.

The rollable OTFT-driven OLED display measures 4.1-inches wide and just 80 micrometers thick. It has a resolution of 432 x 240 pixels at 121 pixels per inch (ppi), which Sony says makes it the world’s highestresolution OTFT-driven OLED display. It can produce 16.8 million colors with a peak brightness of over 100 cd/m2 peak and contrast ratio of greater than 1000:1.

Because the organic materials used to create the display are easily dissolved in common solvents Sony will proceed with the development of a solution/print based process to manufacture such display devices. This process requires fewer steps, and consumes materials and energy more efficiently, resulting in a smaller environmental impact compared to the conventional high temperature vacuum semiconductor process used for inorganic, silicon materials.

Sony says it will continue to improve the performance and reliability of its flexible organic displays as it expects the technology to yield thin, light-weight, durable and mobile devices with previously unachievable form factors.

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e-Paper & e-Book http://www.parc.com/newsroom/media-library.html A premier center for commercial innovation, PARC, a Xerox company, is in the business of breakthroughs.

Flexible display credit: Brian Tramontana A novel PARC process enables jet-printing organic semiconductors and conductors. Additively printed polymer TFT arrays on plastic substrates can enable low-cost displays with new functionality and performance.

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ITRI - http://www.digitimes.com/news/a20081218PD218.html ITRI introduces flexible OLED displays Susie Pan, Taipei; Meiling Chen, DIGITIMES December 2008

ITRI's 4.1-inch AMOLED panels Photo: Susie Pan, Digitimes, December 2008

Taiwan's Industrial Technology Research Institute (ITRI) has introduced a series of flexible display technologies, including active matrix (AM) OLED displays, roll-to-roll cholesterol liquid crystal displays and electrowetting displays.

John Chen, general director of display technology center (DTC) at ITRI, pointed out that flexible display technology combines the advantages of large-size, light weight, roll-to-roll manufacturing, low cost, and energy saving.

ITRI's 4.1-inch AMOLED panels are produced on plastic substrates. The panel can display images even when it is curved. Although the trial product is only monochrome, panel makers can adopt ITRI's technology with multi-color materials to mass produce flexible OLED and roll-to-roll panels, said Chen.

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e-Paper & e-Books - http://www.itri.org.tw/eng/news-and-events/feature-story-detail.asp?RootNodeId=050&NodeId=0502&FocusNewsNBR=56 ITRI's Color AMOLED Display Flex Your Digital Life April 2010

Rollable AMOLED The first step towards developing rollable screens for electronic books or cell phones is to produce flexible Active Matrix Organic Light-Emitting Diodes (AMOLED). ITRI’s achievement in this field is its 4.1” polychrome AMOLED, which is also ITRI’s newest and most advanced breakthrough in the area of flexible display panels.

ITRI’s development in flexible technology, such as PI substrates, has already been applied by AUO, in its large size active matrix and back panel technologies. When integrated with the EPD monitor, reusable and rollable electronic paper is produced, and these will be applied towards future electronic reading devices.

- http://www.techspot.com/news/40958-researchers-develop-01mm-flexible-amoled-display.html Researchers develop 0.1mm flexible AMOLED display

By Emil Protalinski, TechSpot.com November , 2010

The Industrial Technology Research Institute (ITRI) in Taiwan has built a flexible 6-inch AMOLED display that is just 0.1mm thick, according to OLED-Info. The technology, named FlexUPD, reportedly enables a folding radius of 5cm or less while still being able to withstand repeated folding. In other words, it can continue to display images even when folded. The ITRI claims each display can be folded up to 15,000 times before showing signs of wear and tear.

FlexUPD's unique property is in its use of a "de-bonding layer" between the glass and flexible substrate, which sticks to the production glass substrate firmly during the entire fabrication process and is completely non-adhesive to the polyimide film stacked on top. This allows the active matrix backplane used for highquality color displays to be flexible.

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ITRI claims FlexUPD will prove to be the simplest and cheapest option for mass producing flexible displays.

FlexUPD will be commercialized soon and companies are already announcing plans to use it for flexible ereader products, although the institute has not yet provided pricing estimates or a production timeline.

The technology will be quite useful for gadgets such as the Amazon Kindle. Other large companies in the industry, including Sony and LG, are working on flexible e-paper displays as well. Nevertheless, we're still a long way off from the days when we can buy a newspaper built using a flexible and thin display and not have to worry about losing it on our way to work.

□□□□□ http://forum.dailymobile.se/index.php?topic=34521.0 Foldable Display

Another prototype showing off a 5.3-inch display (animated) that was foldable in the middle which didn’t surprise me since I also saw a few flexible displays on the way to this one. It has a 960 x 800 resolution (235 PPI), 26.2K colors, 250 cd/m2 brightness, 100K:1 contrast, > 100% NTSC color space.

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A few displays with flexible, animated displays, 4.3-inch in size * FPD International is a comprehensive and world-class exhibition of the latest display technologies including FPDs (LCD, OLED, PDP,etc.), next generation display technologies such as touch panels, e-paper and 3D, and cutting-edge manufacturing equipment, components, manufacturing process, materials and technologies.

- http://electronics.howstuffworks.com/oled.htm Foldable OLED Foldable OLEDs have substrates made of very flexible metallic foils or plastics. Foldable OLEDs are very lightweight and durable. Their use in devices such as cell phones and PDAs can reduce breakage, a major cause for return or repair. Potentially, foldable OLED displays can be attached to fabrics to create "smart" clothing, such as outdoor survival clothing with an integrated computer chip, cell phone, GPS receiver and OLED display sewn into it. © 1998-2008 HowStuffWorks, Inc.

□□□□□ Flexible OLED http://www.oled-display.net/flexible-oled -

video

□□□□□ - http://ielab.hanyang.ac.kr/ielab/research1_.html Deep technical about Display Electronics (LCD-OLED)

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e-Paper & e-Book - http://winarco.com/lg-introduces-lg-flexible-e-ink-display/ LG Displayed Flexible e-Papers This Year, Will Start Making Them Soon

by Kevin Xu on August 26, 2010

From The SEC filling, someone has revealing the intention of LG to start mass producing their flexible epapers display that could be potential to be the future e-newspaper. LG will start producing 9.7-inch color epaper displays, and 19-inch flexible bendable epapers (which illustrated on the picture above) later in this year.

The flexible was showcased earlier in this year, LG 19-inch flexible e-paper is at weighs in just 130 grams and itâ&#x20AC;&#x2122;s super thin at 0.3mm thick. Meanwhile, the 9.7-inch display is not flexible, so they are aiming to include the display to their new ebook readers or tablet.

[An SEC filing is a financial statement or other formal document submitted to the U.S. Securities and Exchange Commission (SEC)]

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e-Paper & e-Books - http://www.sonyinsider.com/2010/09/14/sony-shows-off-prototype-flexible-electronic-paper-display/ Sony Shows Off Prototype Flexible Electronic Paper Display Christopher MacManus on September 2010

Sony had a never before seen prototype of flexible electronic paper display technology at the 2010 Dealer Convention. Usually, E-paper has used glass substrate in the past but this new technology uses plastic substrate. Glass substrate is heavier and more prone to damage than plastic substrate, which is much lighter and can also be bent. Electronic paper with plastic substrate is also very difficult to break even when you drop it, and can even be rolled up like real paper.

Sony has not mentioned when it will bring this technology to Reader devices, but judging by these highly advanced concepts we imagine it canâ&#x20AC;&#x2122;t be any longer than a year or two.

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e-Paper & e-Book - http://blog.targethealth.com/?p=14473 Roll-to-roll Plastic Displays A new company puts silicon transistors on plastic for flexible displays Oct 2010

This plastic material is used as the backing for Phicot’s amorphous silicon electronics. Credit: Phicot MIT Technology Review, by Kate Greene – Engineers and technophiles have long dreamt of plastic-based displays that are flexible, lightweight, and rugged compared to their glass-backed counterparts. But plastic screens still aren’t widely available, partly because they’re so hard to manufacture reliably in large numbers.

Now a company called Phicot has adapted a technique for printing amorphous silicon electronics onto plastic that could finally make such displays practical. The manufacturing technique, already used to make cheap solar cells, involves depositing chemicals on long sheets of plastic as they are fed through a series of rollers.

Phicot is a subsidiary of PowerFilm of Ames, IA, which already makes amorphous silicon solar cells using this roll-to-roll process.

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Human-Computer Interaction - http://www.eetimes.com/design/automotive-design/4010069/Practical-considerations-for-capacitivetouchscreen-system-design-Part-1-of-2Practical considerations for capacitive touchscreen system design Yi Hang Wang, Cypress Semiconductor, Product Manager, CapSense Solution Group, Cypress Semiconductor Corp. 7/28/2008

Designing a successful projected-capacitance touchscreen system requires careful consideration of the following aspects: device mechanical design, substrate selection and user interface design. Cost and technology tradeoffs are also useful to keep in mind at all stages of the assessment process.

Unlike resistive touchscreen technologies, projected-capacitance touchscreens are better designed to handle finger gesturing, in particular, multi-touch user input. Resistive technologies require finger pressure in order to cause the mechanical layers of the touchscreen to make electrical contact. This makes fluid finger sliding and gesture operations very cumbersome. In addition, the multi-layer mechanical assembly of a resistive touchscreen is prone to early wear-and-tear from repeated usage.

Multi-touch gestures enabled by projected-capacitance touchscreens include common variants such as pinching, zooming, two-finger scolling and rotating. They enable fast and easy manipulating of data, content and user preferences. Portable gaming and text/email applications can also take advantage of multi-touch technology. Multi-touch all-points-addressable (APA) can precisely determines the coordinate location of each finger press in a multi-finger touch event.

Typing shift characters is simply a singular multi-touch event operation instead of having first to shift the character set and then typing the actual shift character. Multi-Touch also has broad applications in GPS navigation. Instead of entering starting and destination addresses, APA enables the selection of end-points right on the screen, making it much faster for people to get to where they want to be. The figure below illustrates some of the possibilities with multi-touch.

Multitouch touchscreens can be used in a wide variety of ways by the user and finger(s) There are several keys questions to answer in order to evaluate a device's mechanical design.

1. Is the cover lens (touch surface) flat or curved?

It is generally recommended that capacitive touchscreen applications should be mounted on flat touch surfaces. Having a curved surface introduces some complications. In order to achieve a robust capacitivesensing design, the transparent touch sensor must be laminated flush along the underside of the cover lens.

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e-Paper & e-Book Any air pockets or "bubbles" caused by lamination unevenness can result in decreased touch performance and impact the overall product aesthetics.

A curved cover lens restricts the choice of touch sensor substrates to PET (polyethylene terephthalate). The plastic sensor will be able to bend to fit the form-factor of the curved cover lens. If a curved cover lens must be used, it is recommended that the degree of curvature does not exceed 45 from the point of inflection.

Having a much steeper curvature makes lamination much more challenging, and can damage the indium tin oxide (ITO) conductive patterning. As a result, production yield may be jeopardized.

Cheaper methods of lamination involving the use of pressure sensitive adhesives (PSA) may not be possible with a curved overlay. Instead, more costly UV-curing liquid polymer adhesives may need to be used to ensure greater lamination integrity. UV-curing adhesives are expensive because they are easy to use, thin, and possess very high optical qualities (greater than >95% transparency).

2. What are the border widths of the cover lens' opaque in-active areas?

For touchscreen sizes of under 4 inches (10 cm), the border widths of the cover lens that are adjacent to the side with the touch sensor tail should be no thinner than 3.0 mm and the side of the touch sensor tail should be no thinner than 10 mm. The required border space is used to hide the non-transparent silver traces linking the transparent ITO pattern to the control circuitry and the control circuitry itself. It may be possible to achieve thinner borders using glass-based substrates but the above guidelines are still recommended.

Non-active border requirements for touchscreens 3. What is the overlay/cover lens material?

The lens/overlay material and any decorative artwork within the touchscreen active area must not use any conductive materials. The use of a conductive material will shield the e-field of the capacitive sensors and drastically reduce the sensing performance. Cover lens should be 1.0 mm or less in thickness.

4. What is the distance between the bottom of the cover lens and the LCM? As portable communication devices strive for slimmer profiles, it is important to consider the gap between the liquid crystal module (LCM) and the cover lens. There must be sufficient space to fit a thin touchscreen sensor as well as an air gap to protect the touch sensor from unwanted radiated EMI interference from the LCM. At least a 0.5 mm gap between the underside of the touch sensor substrate and the LCM is recommended.

5. How am I going to handle ESD? In order to offer protection to electrostatic discharge (ESD) events on the touch surface, a low impedance path to ground must exist through the device. The touch sensor should be protected using a ground ring placed in the non-active border area of the cover lens. The ground ring could be a simple metal foil. It is necessary to ensure that there is a firm connection between the ground ring and device system ground.

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e-Paper & e-Books - http://www.sapdesignguild.org Interaction Design Guide for Touchscreen Full screen Applications should be run full screen.

Backgrounds Bright background colors (no black!) hide fingerprints and reduce glare.

Dithering or other patterned backgrounds help the eye focus on the screen image instead of reflections, even in areas where there are no icons or menu choices.

Handedness As many users are left-handed, the screen layout should be switchable between a version for right-handed users and a version for left-handed users.

Screen Reversal The screen reversal should affect mainly the large building blocks of the screen layout. Whether the controls themselves should also be mirrored, depends on how much interaction is adversely affected by the standard layout of the control. For instance, it depends on, whether a standard control is obscured, if operated with the left hand. Š Copyright 2008 SAP AG. All rights reserved.

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http://www.voltagecreative.com/blog/2008/05/best-practices-of-touch-screen-interface-design/

Best Practices of Touch Screen Interface Design Touch screen interface design is a tricky thing for some people who've been designing for a mouse-bound audience. But with the coming of the iPhone and a host of other touch-screen equipped smart phones at attractive price points (Like the Palm Centro and HTC Touch) I'm thinking about touch screen interfaces more and more. Maybe you should be, too_ 1. Response speed should be of utmost importance. (I know, I know_ making response speed a priority is a staple of user interface programmers and designers, but it's even more important in touch screen world.) The speed and ease with which a human can interact is increased within the touch screen interface environment. Therefore, the interface's responsiveness must increase as well. If your hardware/software's response time is slow, you'll find your user's aggravation increasing proportionally faster than it would if they were using a less intuitive system, such as a mouse or trackball. (It's not as if a using a mouse makes us all plodding computer operators, but no matter how seasoned you are with the click-able rodent, it will never come as naturally as reaching out and touching something to interact with it.) So be lightweight.

2. More space comes in at a close second to speed. A cursor is small and a stylus may be even smaller. However, it's a good idea to design your interface with fat fingers in mind, even if a stylus is expected to be present some of the time. This will increase the overall usability and flexibility of your system. When designing Poptakeout.com (An iPhone/iPod Touch social news aggregator) all the buttons was 106px by 110px. Considering the Mobile Safari platform is displayed (exclusively, as far as I know) on iPhones and iPod Touches, whose displays pack 160dpi, I ended up with buttons almost 1/2o square: plenty of room for an accurate poke.

3. Intuitiveness of your design also becomes a heightened concern. This is the same situation as number one, in the touch screen environment non-intuitive information architecture will be even more frustrating to your users. When all they have to do to is reach out and touch something, it becomes a larger source of frustration when this simple action does not deliver as expected.

4. Ambidextrous design must come into consideration in the touch screen world. Both lefties and righties will be using your interface, so plan accordingly. Delivering the same experience to all users means either vertically symmetrical navigation or an option to flip your layout. I prefer the former, it will take less development time (in general) and simplifies your interface.

5. Bright background colors or patterns can hide glare and reduce fingerprints. Solid black is the worst possible choice. (I'm looking at you, iPhone) 6. Touch screen interfaces are more suited to information retrieval than data entry.

7. Be aware of screen coverage. Flyout or rollover menus become much less useful. You may want to consider placing navigation at the bottom of your touch screen area, with results/display at the top.

(Thanks, Sanj) 8. Problems with eye-finger and eye-stylus parallaxes lend even more credence to the argument for big, fat areas to press with plenty of space between them.

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e-Paper & e-Book 9. Best to worst operations: Point, select > Position, orient (rotate), define path > Enter values > Enter text. So, basically, touch screen interface's are great for data retrieval, pretty good for data manipulation, and are kinda awful for data entry. © Copyright 2008 Voltage Creative

- http://www.organicui.org/?page_id=38 Tangible User Interface and Its Evolution

by Hiroshi Ishii The key idea of TUIs was to give physical forms to digital information TUI makes digital information directly manipulatable with our hands, and perceptible through our peripheral senses by physically embodying it. © Copyright 2008 ACM and/or the authors

- http://www.organicui.org/?page_id=71 What Makes an Interface Feel Organic?

The resulting interface concept and prototype allows users to browse digital media by a combination of physical deformation and 2D position control. Held in both hands, the device can be bent along one axis while a touchpad mounted on the back of the device is used to control 2D position. © 2008 ACM and/or the authors

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Touchscreen - http://electronics.howstuffworks.com/iphone2.htm Touchscreen To allow people to use touch commands that require multiple fingers, the iPhone uses a new arrangement of existing technology. Its touch-sensitive screen includes a layer of capacitive material, just like many other touch-screens. However, the iPhone's capacitors are arranged according to a coordinate system. Its circuitry can sense changes at each point along the grid. In other words, every point on the grid generates its own signal when touched and relays that signal to the iPhone's processor. This allows the phone to determine the location and movement of simultaneous touches in multiple locations. Because of its reliance on this capacitive material, the iPhone works only if you touch it with your fingertip -- it won't work if you use a stylus or wear non-conductive gloves.

A mutual capacitance touch-screen contains a grid of sensing lines and driving lines to determine where the user is touching.

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A self capacitance screen contains sensing circuits and electrodes to determine where a user is touching.

The iPhone's screen detects touch through one of two methods: Mutual capacitance or self capacitance. In mutual capacitance, the capacitive circuitry requires two distinct layers of material.

One houses driving lines, which carry current, and other houses sensing lines, which detect the current at nodes. Self capacitance uses one layer of individual electrodes connected with capacitance-sensing circuitry. © 1998-2008 HowStuffWorks, Inc.

□□□□□ Capacitive - http://www.embedded-systems.com/design/testissue/219500393 Getting in touch with capacitance sensor algorithms Learn about the role of capacitance measurement algorithms in multi-touch sensing user interfaces.

By John Carey, Atmel

Increasingly embedded applications must interact directly with their environment and their end users.

Consider the best new touchscreen phones, in which the user interface is a large capacitive sensing screen that differentiates a flick from a tap and tracks the motion of your finger but doesn't track your ear.

Sensors are at the heart of these systems. They sense the environment and user behavior, enabling the product to respond in an intuitive but reliable way. However, the sensor films themselves aren't intelligent.

They don't even collect data. They only sense. They aren't capable of differentiating between useful and useless data or discriminating between the quality of different types of inputs.

Truth be told, these sensor films hardly sense at all. They really just project an electric field created by an intelligent capacitive sensing chip. This type of capacitive sensing is known as projected capacitive technology, and it's used in the most advanced capacitive touchscreen solutions. Figure below shows and example of how a projected capacitive touchscreen works.

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This is not to say that the sensors themselves are not complex. On the contrary, a capacitive touchscreen sensor consists of a large array of indium tin oxide (ITO) conductors on one or more layers of glass or polyethylene terephthalate (PET) plastic. Figure below presents an example of a touchscreen sensor construction.

The good optical clarity and low resistivity of ITO make it the perfect conductor for creating a touchscreen.

When the ITO sensor is connected to a capacitive sensing chip with a suitably high signal-to-noise ratio (SNR), it can accurately sense minute changes in capacitance. A finger's presence for instance is on the order of a picoFarad (1012 Farads).

Mutual vs. Self Capacitance There are two approaches to determining finger position with a projected capacitive touchscreen: measuring self capacitance and measuring mutual capacitance. Touchscreen solutions that measure self capacitance measure an entire row or column for capacitive change.

Self capacitance works OK for single-touch systems, but with multi-touch systems there is no way to resolve the positional ambiguity that results from more than one simultaneous touch on different parts of the screen.

For example, if a user touches on the capacitive grid at locations X1, Y1 and X2, Y2, the energized lines simply tell the chip that X1, X2, Y1, Y2 lines have all been touched. It doesn't know the combination thereof.

It could be that the chip reports X1, Y2 and X2, Y1 were the touch locations. This problem is known as ghosting.

Another problem with self-capacitance touchscreens is the snapping effect. It happens when tracking two touches moving towards a shared row or column electrode; the reported coordinates tend to "snap" to that electrode causing a strong nonlinearity and poor user feel.

In contrast, mutual capacitance measurement uses an orthogonal matrix of transmit and receive electrodes arranged as an array of multiple smaller touch nodes created by the geometry of the electrode structure.

In a mutual capacitance based system, each touch is uniquely detected as an xy coordinate pair, whereas in a self capacitance system, the detection of X and Y coordinates of a touch is independent.

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e-Paper & e-Book If two touches are present in a mutual capacitance system, this would be detected as (X1,Y1) and (X2,Y2), whereas in a self-capacitance system it would be detected as (X1,X2,Y1,Y2), leaving two potential combinations of coordinates. The self-capacitance ghosting problem is exponential and becomes impossible to solve as you transition to three or more touches.

A mutual capacitive array is interpreted as a complete touch surface that maintains the ability to resolve multiple touch points within each individual "small" screen. Because the capacitive coupling at each point in the matrix can be measured independently, it means that there is no ambiguity in the reported coordinates for multiple touches. It is then technically possible to have unlimited touch recognition. Figure below compares mutual vs self capacitance.

□□□□□ - http://en.wikipedia.org/wiki/Touchscreen

Mutual Capacitance In mutual capacitive sensors, there is a capacitor at every intersection of each row and each column. A 12by-16 array, for example, would have 192 independent capacitors. A voltage is applied to the rows or columns. Bringing a finger or conductive stylus close to the surface of the sensor changes the local electrostatic field which reduces the mutual capacitance. The capacitance change at every individual point on the grid can be measured to accurately determine the touch location by measuring the voltage in the other axis. Mutual capacitance allows multi-touch operation where multiple fingers, palms or stylus can be accurately tracked at the same time.

Self Capacitance Self capacitance sensors can have the same X-Y grid as mutual capacitance sensors, but the columns and rows operate independently. With self capacitance, the capacitive load of a finger is measured on each column or row electrode by a current meter. This method produces a stronger signal than mutual capacitance, but it is unable to resolve accurately more than one finger, which results in "ghosting", or misplaced location sensing.

□□□□□ - http://www.asiapro.com.hk/capacitive_touch_sensors_en.html How Capacitive Touch Works The principle of capacitive touches works using body capacitance, a finger touch causes a change in capacitance of the sensor, so that the finger position can be detected and calculated by sensing controller IC, and consequent display or response can be made. Capacitive sensors can either be touched with a bare finger or with a conductive device held by a bare hand. There are two types of capacitive touches, including projected capacitive touch (PCT), which AsiaPro mainly develops, and surface capacitive touch.

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e-Paper & e-Books Projected capacitive: There are 2 kinds of patterned sensors structure: single layer and 2 separated layers, both structures support multi-touch and no calibration is needed. They are suitable for small sizes display, can work with protective or decorative cover lens.

Projected capacitance or Projected Capacitive Touch (PCT) technology is a capacitive technology that permits more accurate and flexible operation. It requires 1 single conductive layer to form a grid pattern of electrodes, or 2 layers of separated and perpendicular X-Y array of lines to form the grid of electrode nodes.

By applying voltage to the arrays, a grid of capacitors is created. Bringing a finger or conductive stylus close to the surface of the sensor changes the local electrostatic field. The change of capacitance at every individual point on the grid can be measured, it provides precise identification of the position. The use of grid permits a higher resolution and no need to calibrate, it also allows multi-touch operation and suitable for small sizes touchscreen.

Surface capacitive: It consists of one layer of conductive ITO layer, a small voltage is applied to the layer resulting in a uniform electrostatic field, when a finger touch the screen, a capacitor is dynamically formed and the sensing controller can determine the location of the touch indirectly from the change in the capacitance measured from the four corners of the panel. As surface capacitive is prone to false signals from parasitic capacitive coupling and EMI, it needs calibration regularly. Also, it does not support multi-touch function and not suitable for small sizes touch screen.

□□□□□ - http://www.asiapro.com.hk/capacitive_touch_sensors_en.html rojected capacitive touch (PCT) technology is the most powerful and adaptable user interfaces available in touch screens application. Projected capacitive touch sensors provide the means for direct and immediate user interaction. They are contactless, solid-state sensors without moving parts. No pressure is needed to active the capacitive sensor which is covered by protective insulating layers, all that required is only a gentle touch over a key or glide along the surface of a capacitive touch screen.

□□□□□ Resistive - http://www.asiapro.com.hk/resistive_touch_panels_en.html How Resistive Touch Works

4-Wire Resistive Technology A resistive touch panel is a mechanical sensor. It consists of 2 conductive ITO layers separated by air gap and tiny transparent insulation spacer dots. When a finger or stylus presses on the top layer of ITO PET film (usually X axis), which means that it physically touches the lower layer of ITO glass substrate (usually Y axis), the voltage at the contact point is measured through the 4-wire printed on the edges of both ITO layers, and then the location can be computed by the controller. After the finger or stylus releases, the top layer resumes to its original position.

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□□□□□ - http://www.eetimes.com/electronics-products/embedded-tools/4110474/Flexible-touchscreen-debuts Flexible touchscreen debuts R Colin Johnson - February 2009

PORTLAND, Ore. — Arizona State University's Flexible Display Center (FDC) and its military and industry partners are claiming the first flexible touchscreen integrated with an active-matrix display. The light-weight device is initially headed for the battlefield.

Based on active-matrix electrophoretic display technology from E-Ink Corp. (Cambridge, Mass.) the new flexible touchscreen uses materials supplied by DuPont Teijin Films, which manufacturers the plastic used as a substitute for glass in conventional touchscreens.

"Our displays have always been flexible, but so far the touchscreens have been glass, which are not rugged enough for many applications," said Sri Peruvemba, E-Ink's vice president of marketing. "Now we have a partner that can build a flexible touchscreen to match our flexible display."

Glass touchscreens can only be used when securely enclosed in a hard-shell housing. For future commercial applications like e-newspapers, however, a more durable flexible touchscreen is needed that would allow users to navigate using on-screen icons, then roll up the e-paper for carrying and storage.

Flexible displays will eventually be used with full-color technologies for paper-thin displays that bend and flex.

"Now that our whole device can be made flexible, it should also enable larger-sized touchscreens for electronic newspapers, textbooks and other larger format applications," said Peruvemba.

"There are three distinct elements: the E Ink Visplex display, the plastic backplane and the touchscreen--the integration of which is the result of a collaboration between the FDC, DuPont Teijin Films and E Ink," said Shawn O'Rourke, director of engineering at FDC. Inductive technology allows users to touch the screen with a finger or a stylus. Like E Ink's display, the touchscreen consumes power only when its contents are being changed. In writing mode, information sketched on the display can be stored, then erased.

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e-Paper & e-Books Designed to be sufficiently rugged for use on the battlefield, the display also is extremely thin compared to traditional glass touchscreens. The paper-thin display should reduce soldiers' load, and its low power consumption eliminates the need for a heavy lithium-ion battery used with ordinary LCD-based laptop computer displays.

□□□□□ - http://www.technologyreview.com/computing/25633/?a=f Flexible Touch Screen Made with Printed Graphene Sheets of atom-thick carbon could make displays that are super fast.

By Nidhi Subbaraman - June 2010

Researchers have created a flexible graphene sheet with silver electrodes printed on it (top) that can be used as a touch screen when connected to control software on a computer (bottom).

Credit: Byung Hee Hong, SKKU. Graphene, a sheet of carbon just one atom thick, has spectacular strength, flexibility, transparency, and electrical conductivity. Spurred on by its potential for application in new devices like touch screens and solar cells, researchers have been toying with ways to make large sheets of pure graphene, for example by shaving off atom-thin flakes and chemically dissolving chunks of graphite oxide. Yet in the thirty-some years since graphene's discovery, laboratory experiments have mainly yielded mere flecks of the stuff, and mass manufacture has seemed a long way away.

"The future of the field certainly isn't flaking off pencil shavings," says Michael Strano, a professor of chemical engineering at MIT. "The large-area production of monolayer graphene was a serious technological hurdle to advancing graphene technology."

Now, besting all previous records for synthesis of graphene in the laboratory, researchers at Samsung and Sungkyunkwan University, in Korea, have produced a continuous layer of pure graphene the size of a large television, spooling it out through rollers on top of a flexible, see-through, 63-centimeter-wide polyester sheet.

"It is engineering at its finest," says James Tour, a professor of chemistry at Rice University who has been working on ways to make graphene by dissolving chunks of graphite. "[People have made] it in a lab in little tiny sheets, but never on a machine like this."

The team has already created a flexible touch screen by using the polymer-supported graphene to make the screen's transparent electrodes. The material currently used to make transparent electronics, indium tin oxide, is expensive and brittle. Producing graphene on polyester sheets that bend is the first step to making transparent electronics that are stronger, cheaper, and more flexible. "You could theoretically roll up your iPhone and stick it behind your ear like a pencil," says Tour.

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e-Paper & e-Book - http://news.discovery.com/tech/an-unbreakable-touch-screen-for-your-phone.html An Unbreakable Touch Screen for Your Phone Analysis by David Teeghman Wed Jun 23, 2010

Anyone with a smart phone or an iPad will tell you touch screens are the way of the future. But touch screens have some serious drawbacks, such as how expensive they are, not to mention easily breakable.

But a new type of touch screen could be less expensive and more durable. Researchers in South Korea and Japan write in the journal Nature that they can make large pieces of graphene films, up to 30 inches long, for touch screen phones and flat panel TVs. Most touch screens in phones are now made with indium tin oxides (ITO). The ITO's greatest asset is that it's transparent, but it comes with a cost. ITO is exceedingly expensive, because it's made of rare materials. And my girlfriend's third iPhone in one year is a testament to the fact that the screens are easily breakable.

Electronics companies have been looking for a replacement for the ITO. One option includes carbon nanotubes, which are now being used to develop lithium-ion batteries for portable electronics that should last ten times longer than current batteries. But carbon nanotubes don't work well because they tend to have small defects that create visible areas of “dead” pixels in displays.

Graphene screens are almost completely transparent (like the ITOs), and are highly conductive and very strong (not like the ITOs).

Graphene screens have been around since 2004, but this is the first time that researchers were able to successfully produce them in larger quantities in a roll-to-roll production. In their tests, researchers incorporated the graphene electrodes into a fully functional touch-screen panel, where they outperformed standard ITO electrodes.

As for when graphene screens will become mainstream, researchers won't say, so it's probably wise to invest in a protective case for your phone until then.

Photo: Nature Nanotechnology/Sukang Bae

□□□□□ - http://www.impactlab.net/2010/06/21/flexible-touch-screen-made-with-printed-graphene-could-makedisplays-super-fast/ Flexible Touch Screen Made with Printed Graphene Could Make Displays Super Fast June 2010

Graphene, a sheet of carbon just one atom thick, has spectacular strength, flexibility, transparency, and electrical conductivity. Spurred on by its potential for application in new devices like touch screens and solar cells, researchers have been toying with ways to make large sheets of pure graphene, for example by shaving off atom-thin flakes and chemically dissolving chunks of graphite oxide. Yet in the thirty-some years since graphene’s discovery, laboratory experiments have mainly yielded mere flecks of the stuff, and mass manufacture has seemed a long way away.

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e-Paper & e-Books “The future of the field certainly isn’t flaking off pencil shavings,” says Michael Strano, a professor of chemical engineering at MIT. “The large-area production of monolayer graphene was a serious technological hurdle to advancing graphene technology.”

Now, besting all previous records for synthesis of graphene in the laboratory, researchers at Samsung and Sungkyunkwan University, in Korea, have produced a continuous layer of pure graphene the size of a large television, spooling it out through rollers on top of a flexible, see-through, 63-centimeter-wide polyester sheet.

“It is engineering at its finest,” says James Tour, a professor of chemistry at Rice University who has been working on ways to make graphene by dissolving chunks of graphite. “[People have made] it in a lab in little tiny sheets, but never on a machine like this.”

The team has already created a flexible touch screen by using the polymer-supported graphene to make the screen’s transparent electrodes. The material currently used to make transparent electronics, indium tin oxide, is expensive and brittle. Producing graphene on polyester sheets that bend is the first step to making transparent electronics that are stronger, cheaper, and more flexible. “You could theoretically roll up your iPhone and stick it behind your ear like a pencil,” says Tour.

Researchers have created a flexible graphene sheet with silver electrodes printed on it that can be used as a touch screen.

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A freshly made sheet of graphene is transferred onto a polyester sheet as it passes between hot rollers.

The Korean team built on rapid advances in recent months. “The field really has advanced in the past 18 months,” says Strano. “What they show here is essentially a monolayer over enormous areas–much larger than we’ve seen in the past.”

Last year, Rodney Ruoff and his team at the University of Texas in Austin showed that graphene could be grown on copper foil. Carbon vaporized at 1,000 degrees would settle atom-by-atom on the foil, which was a few centimeters across. Byung Hee Hong, a professor at Sungkyunkwan University and corresponding author on the paper, says the use of a flexible base presented a solution to the graphene massmanufacturing dilemma. “[This] opened a new route to large-scale production of high-quality graphene films for practical applications,” says Hong. “[Our] dramatic scaling up was enabled by the use of large, flexible copper foils fitting the tubular shape of the furnace.” And the graphene sheets could get even bigger. “A roll-to-roll process usually allows the production of continuous films,” says Hong.

In Hong’s method, a sheet of copper foil is wrapped around a cylinder and placed in a specially designed furnace. Carbon atoms carried on a heated stream of hydrogen and methane meet the copper sheet and settle on it in a single uniform layer. The copper foil exits the furnace pressed between hot rollers, and the graphene is transferred onto a polyester base. Silver electrodes are then printed onto the sheet.

The technique shows some potential to be scaled up for mass production. “They particularly show that they are able to grow the graphene [in a way] that is compatible with manufacturing,” says Strano. “It’s a very economical way to manufacture materials.”

Hong sees application for the method in the production of graphene-based solar cells, touch sensors, and flat-panel displays. But he says products will be a while in coming. “It is too early to say something about mass production and commercialization,” he says. Current manufacturing processes for indium tin oxide use a spreading technology that is different from roll-to-roll printing. “However, the situation will be changed when bigger flexible-electronics markets are formed in the near future,” Hong says.

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e-Paper & e-Books - http://www.wacom.com/pressinfo/press_release.php?id=132 Wacom® And E Ink® Partnership Delivers Pen Input To Electronic Paper Displays Combined expertise provides innovative and flexible human interface solutions to mobile computing platforms.

Tokyo, Japan, Vancouver, WA, Cambridge, MA, - May 2008

Wacom and E Ink Corporation announced today a partnership that will integrate Wacom’s Penabled® digital pen input solution with E Ink’s Vizplex™ electronic paper displays. With pen input high on the list of many eBook, Tablet PC, eNewspaper, PDA, eNotepad and appliance-type designers, the Wacom and E Ink partnership comes at an ideal time for mobile computing manufacturers looking to develop new and exciting consumer products. E Ink's customers include Lexar, Motorola, Sony, Amazon, Citizen, Casio-Hitachi, iRex, Polymer Vision and Plastic Logic among others.

□□□□□ http://www.irextechnologies.com/products/technology WACOM Penabled® The iRex iLiad has a WACOM sensor board integrated into its design. This WACOM sensor board utilizes EMR® (Electro-Magnetic Resonance) Technology.

Thanks to the EMR technology there is no need for any cable or built-in battery-based power supply at all.

Upon removal of the Stylus from the socket, the sensor board surface will generate a magnetic field, the Stylus’ resonant circuit then makes use of this energy to return a magnetic signal to the sensor board surface.

By repeating this movement, the board detects information on the pen’s coordinate position and angle, as well as on its general operating condition like speed and motion.

The result is a very precise and easy way to navigate through the iLiad interface or interact with the content and a very natural writing experience when making notes or annotations on your iLiad The Principles of EMR® Technology http://www.wacom-components.com/english/technology/emr.html

□□□□□ - http://www.infoworld.com/t/hardware/e-paper-displays-move-step-closer-real-paper-418 E-paper displays move a step closer to real paper New electronic paper display, with a touch panel and a newly developed control chip, makes it easy for users to annotate pages in e-books and make amendments to documents

By Martyn Williams, IDG News Service

A new electronic paper display could allow users to annotate pages in electronic books, make amendments to documents, and erase parts of the page with as much ease as using a real pen and paper.

The screen, on show Wednesday at the Display 2008 exhibition in Tokyo, was developed by E-Ink, Taiwan's Prime View International, and Japan's Seiko Epson. It combines a conventional electronic paper display with a touch panel and a newly developed control chip.

The chip, from Seiko Epson, can control a screen with up to four times the resolution of current "writable" epaper devices such as iRex Technologies' iLiad.

Seiko Epson's chip also refreshes the display faster than the iLiad can, eliminating the slight lag between movement of the stylus and its effect on the screen.

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Flexible transparent interactive film - http://www.displax.com/ SKIN Displax - Interactive Systems Transparent polymer film that can be applied to non conductive materials and turn them interactive. Very thin, it uses projected capacitive technology, making it possible to apply on the back of a glass and detect finger touch on the front of the glass.

Benefits · Turn any non metallic surface interactive · Display interactive contents in unusual places · Let your audience engage with you Features · Flexible transparent interactive film · Interactivity goes through non metallic materials up to 17mm of thickness · Sizes from 30'' to116* *Standard specifications, custom-made units can be produced Specifications · MATERIAL: Flexible and transparent electronics polymer · DETECTION METHOD: Nanowires grid technology polymer-based · CONNECTION: USB and Serial (different sizes)

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Laser Projection Keyboard http://www.billbuxton.com/projViz.html Projection/Vision Devices Recently a new class of device has started to emerge which is conceptually rooted in exploiting this input/output duality. They can be called Projection/Vision systems, and/or Projection/Scanning or Projection/Camera technologies. In the "pure" case, these are devices that use a laser, for example, to project an image of the input controller - such as a slider or keypad - onto a surface. In doing so, they are performing a function analogous to an LCD displaying the image of a virtual device under a touch screen.

However, in this case, the laser is also used to scan the same surface that it projecting onto, thereby enabling the device to "see" how your fingers, for example, are interacting with the projected virtual device.

- http://www.pdahut.com/store/product.php?productid=19495 Celluon LaserKey CL850 Bluetooth Laser Keyboard This revolutionary mobile input device can be used as a mouse as well as a keyboard

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e-Paper & e-Books - http://www.palminfocenter.com/view_story.asp?ID=6766 iBiz Laser Projection keyboard The Virtual Keyboard (VKB) utilizes laser and infrared technology and projects a full-size keyboard onto any flat surface. As you type on the laser projection, it analyzes what you're typing by the coordinates of that location

- http://www.virtualdevices.net/Demo2-10Flash.html Virtual Devices, Inc. The Virtual Keyboard (VKPC) is a truly innovative and revolutionary product. It presents a projected keyboard on virtually any surface and is essentially damage and maintenance free.

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Braille e-Books for people with severe vision impairment

- http://spie.org/x39224.xml?ArticleID=x39224 Electroactive polymers for rigid-to-rigid actuation and Braille e-books Qibing Pei, Zhibin Yu, Xiaofan Niu, and Paul Brochu February 2010, SPIE Newsroom. DOI: 10.1117/2.1201002.002632

Bistable electroactive polymers comprise a new category of smart materials that can achieve electrically induced rigid deformation.

We have developed a new bistable electroactive polymer (BSEP) that is rigid, can be actuated reversibly and repeatedly to greater than 100% strain, and has a rigid and stable deformed shape. Our BSEP is used to develop Braille versions of electronic books.

The first BSEP that we demonstrated experimentally is based on poly(tert-butylacrylate) (PTBA), a thermoplastic polymer that is rigid in ambient conditions.

Six-dot diaphragm actuator displaying â&#x20AC;&#x2DC;UCLAâ&#x20AC;&#x2122; in Braille letters.

We are currently optimizing processing and patterning approaches for refreshable Braille displays. Our goal is to demonstrate a page-size electronic reader for people with severe vision impairment to read and communicate using the Internet.

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The Electronic Display of the Future - http://spectrum.ieee.org/computing/hardware/the-electronic-display-of-the-future/0

The Electronic Display of the Future Kindle, iPad, Droid—these compact mobile devices are essentially all display. But the screens aren't all we'd like them to be. Yet.

By Jason Heikenfeld - March 2010

No fewer than half a dozen different technologies are emerging from laboratories to compete to be the ereader screen of the future.

When the ultimate display arrives, the e-reader or roll-up computer will be only one of its many applications.

Besides the Kent State technology, which could make the entire casing of an electronic device a reconfigurable display, we’ll also see a boom in electronic supermarket shelf labeling. Electronic shelf labels have started to appear in Europe and a few other markets. These labels can reduce a full day’s chore of relabeling grocery store shelves into an instant, downloadable activity. It also lets stores adapt pricing to consumer habits in real time—a senior citizen shopping midmorning may get different bargains than those picked up by a professional stopping on the way home from work.

Some of these display technologies may make their way into buildings. E-paper technologies like polymerdispersed liquid crystals and electrochromic displays are beginning to cross over into ”smart” window applications. Windows that shade themselves electronically are already on the market, but smart windows could reflect the infrared portion of the sun in summer and transmit it in winter. This technology may first appear in switchable opaque/transparent glass refrigerator doors, which won’t face the potential UV degradation of windows. You’ll also see these low-power, high-visibility displays coming into signage and billboards; today’s LED billboards use lots of energy. Companies like Israel’s Magink are applying cholesteric liquid crystal technology like that used at Kent to large billboards and already have a few in use.

□□□□□ - http://www.displayforum.de/technologies.htm Flat Panel Display Technologies Emerging Display Technologies + 3D Technologies German Flat Panel Display Forum (DFF) The German Flat Panel Display Forum (DFF) is the industry-led flat panel display association under the umbrella of the German Engineering Federation VDMA.

Plasma Display Panels (PDP) Vacuum Fluorescence Displays (VFD) Field Emission Displays (FED) Electroluminescence Displays (ELD) Light Emitting Diodes (LED) Organic Light Emitting Diodes(OLED)

Passive matrix-LCD Active matrix-LCD MEMS (DMD) E-paper Flat panel displays

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3D Technologies Volumetric displays (from companies such as Actuality systems) are those that emit, redirect, diffuse, or reimage light from a localized true volume as integrated over the systemâ&#x20AC;&#x2122;s refresh rate. Examples of volumetric displays include swept-screen multi-planar displays, projection onto a stack of LC panels, two-step upconversion in doped solids, and even projection into fog.

Holographic displays (which some consider to be a form of volumetric display) utilize lasers to reconstruct objects whose scattered light is received by a photographic plate during recording. The front, sides and back of the object can be recorded on three, four or more photographic plates. Such holograms can give 360 degree views of the object. The main difficulty of such displays has been due to the enormous information content of the holograms as well as the difficulty of representing a full color spectrum.

Stereoscopic displays create a right eye-view and a left-eye view that are reconstructed with the use of special glasses, which can be based on differences in color, time, or sequence. Stereoscopic displays are currently the most common and are commercially available in LCD, PDP, and as both rear and front projection systems.

Autostereoscopic displays create multiple viewpoints so the viewer does not have to wear special glasses.

This can be accomplished by headtracking solutions or by reducing resolution to enablemultiple viewpoints.

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Volumetric displays - http://en.wikipedia.org/wiki/Volumetric_display Volumetric display device is a graphical display device that forms a visual representation of an object in three physical dimensions, as opposed to the planar image of traditional screens that simulate depth through a number of different visual effects. One definition offered by pioneers in the field is that volumetric displays create 3-D imagery via the emission, scattering, or relaying of illumination from well-defined regions in (x,y,z) space. Though there is no consensus among researchers in the field, it may be reasonable to admit holographic and highly multiview displays to the volumetric display family if they do a reasonable job of projecting a three-dimensional light field within a volume.

Most, if not all, volumetric 3-D displays are autostereoscopic; that is, they create 3-D imagery visible to the unaided eye. Note that some display technologists reserve the term “autostereoscopic” for flat-panel spatially-multiplexed parallax displays, such as lenticular-sheet displays. However, nearly all 3-D displays other than those requiring headwear, e.g. stereo goggles and stereo head-mounted displays, are autostereoscopic. Therefore, a very broad group of display architectures are properly deemed autostereoscopic.

Volumetric 3-D displays embody just one family of 3-D displays in general. Other types of 3-D displays are: stereograms / stereoscopes, view-sequential displays, electro-holographic displays, parallax "two view" displays and parallax panoramagrams (which are typically spatially-multiplexed systems such as lenticularsheet displays and parallax barrier displays), re-imaging systems, and others.

Although first postulated in 1912, and a staple of science fiction, volumetric displays are still under development, and have yet to reach the general population. With a variety of systems proposed and in use in small quantities — mostly in academia and various research labs — volumetric displays remain accessible only to academics, corporations, and the military.

A volumetric display using a pulsed laser to create balls of plasma in air. http://www.aist.go.jp/aist_e/latest_research/2006/20060210/20060210.html

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Every second, approximately 6,000 planar cross-sections of a 3-D volume are projected onto a spinning diffuser in the Perspecta volumetric 3-D display (made by the former Actuality Systems, Inc.). This is a 10" (25 cm)-diameter volume-filling image of an external beam radiation oncolgy image for brain cancer.

The haptic interface is the PHANTOM Omni (SensAble Technologies, Inc.).

The photograph was taken by Gregg Favalora of Actuality Systems.

□□□□□ - http://www.physorg.com/news149167125.html Improved Volumetric Displays May Lead to 3D Computer Monitors December 2008 By Lisa Zyga

The Perspecta volumetric display generates 3D images, and is based on a sweeping plane that performs 24 rotations per second. (Right) A 3D volumetric image of a rabbit.

Image credit: Benjamin Mora, et al.

(PhysOrg.com) -- Volumetric 3D displays have been around for nearly a century, but they face several challenges that have prevented their use in widespread applications. Recently, a team of researchers from the UK and the US have made some significant improvements that may pave the way toward commercializing volumetric displays for 3D viewing.

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e-Paper & e-Books Volumetric displays involve thousands of 3D pixels (or “voxels” for “volume elements”) that either absorb or emit light from an “isotropically emissive light device” (IEVD). The voxels are projected onto a screen that rotates 24 times per second, creating a 3D image. Because the image is composed of either the presence of absence of light, it creates an X-ray-like effect of the input data. Ideally, the technique could be used for data visualization, such as viewing complex mathematical surfaces, technical designs, and biological and chemical structures, as well as for entertainment purposes.

Researchers Benjamin Mora and Min Chen of Swansea University in Singleton Park, Swansea, UK, along with Ross Maciejewski and David S. Ebert of the Purdue School of Electrical and Computer Engineering in West Lafayette, Indiana, US, have developed a technique that improves the image quality in volumetric 3D displays.

□□□□□ -

http://www.dgp.toronto.edu/~gf/Research/Volumetric%20UI/volumetricResearch.htm

Volumetric User Interfaces Volumetric Displays hold the promise of viewing an electronic display from any direction, walking around it, and experiencing a rich perception of depth without wearing special glasses or headgear. However, little research has been done on what it may be like to interact with these systems. In this research we attempt to outline the fundamental user interface design options for Volumetric Displays. Since Volumetric Display technology is still in its infancy, we simulate mature display and input technology using Wizard-of-Oz prototyping techniques to gain an understanding into the user interface issues.

Research Collaborators • Ravin Balakrishnan • Gordon Kurtenbach • Actuality-Systems Inc.

Working 3D Volumetric Display from Actuality Systems.

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video

e-Paper & e-Book - http://actuality-medical.com/site/content/perspecta_display1-9.html Perspecta Display 1.9 - No-Goggles Spatial 3-D for the Workgroup The Perspecta Display is the cornerstone of the Perspecta Spatial 3-D System: Spatial 3-D. Floating, hologram-like, interactive imagery.

Full parallax. 360-degree field of view, 10” / 25 cm diameter images.

Autostereoscopic. No goggles – and many simultaneous users.

Plug and play. Drops right in to most OpenGL-based applications.

The Perspecta Spatial 3-D System v1.9 creates 10”-diameter three-dimensional imagery.

Key Technical Features • Image Size: 10” (25 cm)-diameter Spatial 3-D imagery • Field of View: 360º horizontal, 270º vertical • Resolution: 198 slices (~1 slice / degree), 768 x 768 pixels / slice • Full Color, now with 2-D and 3-D OpenGL texture-mapping support • Dimensions: 48” high x 31” wide x 22.25” deep

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3-D hologram movie - http://uanews.org/node/35220 A team led by the UA's Nasser Peyghambarian has developed a new type of holographic telepresence that allows the projection of a three-dimensional moving image without the need for special eyewear such as 3D glasses or other auxiliary devices.

A team led by optical sciences professor Nasser Peyghambarian developed a new type of holographic telepresence that allows the projection of a three-dimensional, moving image without the need for special eyewear such as 3D glasses or other auxiliary devices. The technology is likely to take applications ranging from telemedicine, advertising, updatable 3D maps and entertainment to a new level.

The journal Nature chose the technology to feature on the cover of its Nov. 4 issue.

"Holographic telepresence means we can record a three-dimensional image in one location and show it in another location, in real-time, anywhere in the world," said Peyghambarian, who led the research effort.

"Holographic stereography has been capable of providing excellent resolution and depth reproduction on large-scale 3D static images," the authors wrote, "but has been missing dynamic updating capability until now."

"At the heart of the system is a screen made from a novel photorefractive material, capable of refreshing holograms every two seconds, making it the first to achieve a speed that can be described as quasi-realtime," said Pierre-Alexandre Blanche, an assistant research professor in the UA College of Optical Sciences and lead author of the Nature paper.

The prototype device uses a 10-inch screen, but Peyghambarian's group is already successfully testing a much larger version with a 17-inch screen. The image is recorded using an array of regular cameras, each of which views the object from a different perspective. The more cameras that are used, the more refined the final holographic presentation will appear.

That information is then encoded onto a fast-pulsed laser beam, which interferes with another beam that serves as a reference. The resulting interference pattern is written into the photorefractive polymer, creating and storing the image. Each laser pulse records an individual "hogel" in the polymer. A hogel (short for holographic pixel) is the three-dimensional version of a pixel, the basic units that make up the picture.

The hologram fades away by natural dark decay after a couple of minutes or seconds depending on experimental parameters. Or it can be erased by recording a new 3D image, creating a new diffraction structure and deleting the old pattern.

Peyghambarian explained: "Let's say I want to give a presentation in New York. All I need is an array of cameras here in my Tucson office and a fast Internet connection. At the other end, in New York, there would be the 3D display using our laser system. Everything is fully automated and controlled by computer. As the image signals are transmitted, the lasers inscribe them into the screen and render them into a threedimensional projection of me speaking."

The overall recording setup is insensitive to vibration because of the short pulse duration and therefore suited for industrial environment applications without any special need for vibration, noise or temperature control.

One of the system's major hallmarks never achieved before is what Peyghambarian's group calls full parallax: "As you move your head left and right or up and down, you see different perspectives. This makes for a very life-like image. Humans are used to seeing things in 3D." The work is a result of a collaboration between the UA and Nitto Denko Technical, or NDT, a company in Oceanside, Calif. NDT provided the polymer sample and media preparation. "We have made major advances in photorefractive polymer film fabrication that allow for the very interesting 3D images obtained in our upcoming Nature article," said Michiharu Yamamoto, vice president at NDT and co-author of the paper.

Potential applications of holographic telepresence include advertising, updatable 3D maps and entertainment. Telemedicine is another potential application: "Surgeons at different locations around the world can observe in 3D, in real time, and participate in the surgical procedure," the authors wrote.

The system is a major advance over computer-generated holograms, which place high demands on computing power and take too long to be generated to be practical for any real-time applications.

Currently, the telepresence system can present in one color only, but Peyghambarian and his team have already demonstrated multi-color 3D display devices capable of writing images at a faster refresh rate, approaching the smooth transitions of images on a TV screen. These devices could be incorporated into a telepresence set-up in near future.

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Video http://uanews.org/node/35109

3D Moving Images Possible With New Hologram Technology

□□□□□ - http://news.discovery.com/tech/holographic-3d-tv.html New Hologram Tech Sets 3D in Motion Real-time 3D TV may be just around the corner.

Nov 3, 2010 Content provided by Marissa Cevallos, Science News

Arizona researchers have created the first 3-D hologram movie that plays almost in real time, they report in the Nov. 4 Nature. It's the fastest known demonstration of telepresence, where a 3-D hologram depicts a scene from another location.

The key to the invention is a new type of plastic that can refresh the hologram once every two seconds.

While that's too slow to watch the World Series in 3-D, the researchers estimated holographic TV could be coming in seven to 10 years.

"It is very very close to reality," says physicist Nasser Peyghambarian of the University of Arizona in Tucson.

"Something that was science fiction is something we can do today."

Holograms are created when light bounces off a sheet of material with grooves in just the right places to project an image away from the surface, like on some credit cards. The image is even crisper when the illuminating light waves march in step, as they do in a laser.

Holographic video is already possible, albeit painfully slow -- the U.S. military records enemy territory in 3-D, but refreshing each frame of the video can take an entire day. The Arizona team created a quicker way to play holographic video in 2008, but with that method each frame still took four minutes to generate. Now, after two years of optimizing the plastic, they've cut the time to just two seconds.

Sixteen cameras snap pictures of an object that are piped into a desktop PC, which processes the data.

Then the computer shoots the holographic pixels, or "hogels," electronically to another location. There, the hogels are transformed into an optical signal and transmitted by a laser onto a plastic screen, much like a projector shines light onto a white screen to play a movie.

When this light hits, the plastic screen undergoes chemical reactions that temporarily record the most recent set of images in the data stream.

A particular color of light illuminates the plastic and -- voila! Light scatters in just the right way to recreate the original image. Then, the new plastic can be erased, creating a clean slate for the next image.

But unlike Princess Leia pleading for help, the new hologram can't float in space. Instead, Leia's image would appear to stick out from a screen's surface. "Star Wars was a great movie and we got a lot of feedback because of Princess Leia," says Arizona physicist Pierre-Alexandre Blanche. But the idea of a hologram hovering in mid-air is impossible. "You need a screen, a support to display the image."

Within a few months, the Arizona team hopes to create holographic video on a tabletop, where laser light shines up from underneath a table.

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e-Paper & e-Books Before holographic devices hit living rooms, though, the holograms need to be bigger and faster. The researchers will have to upgrade their 50 hertz laser to one that operates at faster gigahertz speeds, scale up the size of the screen, and miniaturize their instrumentation.

"But I don't think there's any fundamental physics that would prevent us from getting there," Peyghambarian says. The exact technological route to holographic TV is still up in the air, as other scientists take different approaches to creating moving holograms."

□□□□□ -

http://www.telepresenceoptions.com/2010/11/holographic_telepresence_break/

Holographic Telepresence Breakthrough Announced at U of A - With Telepresence Options Publisher Howard Lichtman's Thoughts and Analysis

November 2010 | Howard Lichtman

"The prototype device uses a 10-inch screen, but Peyghambarian's group is already successfully testing a much larger version with a 17-inch screen. The image is recorded using an array of regular cameras, each of which views the object from a different perspective. The more cameras that are used, the more refined the final holographic presentation will appear.

That information is then encoded onto a fast-pulsed laser beam, which interferes with another beam that serves as a reference. The resulting interference pattern is written into the photorefractive polymer, creating and storing the image. Each laser pulse records an individual "hogel" in the polymer. A hogel (short for holographic pixel) is the three-dimensional version of a pixel, the basic units that make up the picture.

The hologram fades away by natural dark decay after a couple of minutes or seconds depending on experimental parameters. Or it can be erased by recording a new 3D image, creating a new diffraction structure and deleting the old pattern."

The breakthrough here is that the image is refreshing every two seconds which is a 100 fold improvement from the team's last major announcement. It is a far from the 30 to 60 frames per second that conventional telepresence and videoconferencing systems achieve today albeit in 2D. 30 frames per second is generally considered to be the threshold for fluid, natural motion.

Wired had a great quote from optical scientist Michael Bove of the MIT Media Lab, who was not involved in the new research but is collaborating with Peyghambarian on another project. "This is mostly a materials advance, the material is faster and more sensitive than what had previously been reported."

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e-Paper & e-Book Given the small size of the screen and the two-second lag time, "some people in the field object to the term 'telepresence,'" Bove said.

□□□□□ http://www.sgmt.at/ReferE/Hologram.htm

http://science.howstuffworks.com/hologram.htm

http://www.explainthatstuff.com/holograms.html

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3D display - http://www.crunchgear.com/2010/06/19/a-guide-to-3d-display-technology-its-principles-methods-and-dangers/ A guide to 3D display technology: its principles, methods, and dangers

by Devin Coldewey on June 19, 2010

How depth is created in 3D displays There’s a simple explanation here and a complicated explanation. The simple one first: 3D displays create the illusion of depth by presenting a different image to each eye. That’s it. And that’s something that all 3D displays have in common, no matter what. In a fit of uncommon camaraderie among media and electronics companies, standards were even developed that encode a 3D stream similarly to normal stream, except with totally separate left and right eye images baked right in. There are variations, of course, but it’s a surprisingly practical approach they agreed on.

But how best to display it? Everyone differs in their opinions. Basically you have three fundamental techniques (and a few outdated or simply unused ones I’ll mention briefly) of sending the “right eye” image to the right eye and the “left eye” image to the left.

Filtered lenses

The original. The red-blue, red-green, or magenta-cyan (or “anaglyph,” the coolest word in this story after “parallax barrier”) glasses that came to symbolize 3D split a black-and-white (and later, color) image into two complementary components. I won’t get deep into the mechanics of it (Wikipedia has an excellent entry) but basically it creates an image where part goes to one eye and part to another, and part to both — this last part will be the screen’s “normal plane” where your eyes are to focus, and hence receive similar input.

Troubles are mainly of the color perception variety; it’s extremely hard to balance things so that your brain takes the broken-up colors and assembles them correctly. However, anaglyph is still in use and still relevant — I just watched Toy Story 3 using green-magenta and it looked great. A newer version (by Infitec) uses advanced filters to split each color into two components, sending half the red spectrum to one eye and one to the other, but these haven’t caught on which is part of the Dolby3D system (and which somehow I’ve managed to avoid entirely and think rare).

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The most modern version of filtered lenses (bottom illustration) uses polarization â&#x20AC;&#x201D; originally linear, now circular polarization (RealD) is used, since it allows you to tilt your head without affecting the image. The objection to this tech is that the brightness of the image is essentially halved.

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Active shutter glasses

This is the current method of choice for most 3D TV companies. The media is displayed at a high framerate, and the glasses rapidly switch between black and clear using a pair of low-latency transparent LCD screens.

In this way, one eye sees nothing (for as little as a hundredth of a second or so) while the other sees its “correct” image, and a few microseconds later, the situation is reversed: the opposite eye’s image is displayed and the LCDs have switched. The benefit is that each eye is getting the “full” image whenever it’s getting anything (unless they’re cheating and doing it via interlaced field switching).

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e-Paper & e-Book There are a number of objections to this technology: • The glasses themselves vary in performance. The technology is being improved, and last year’s glasses are outperformed by this year’s glasses… and likely in a few months they will be out of date.

It’s not a bad thing that the tech is improving, but considering the next few point against it, it’s bad news to implement a technology in flux.

• High cost. A single pair of these glasses may cost upwards of $100. The cost of adopting these as an individual is high enough, but for a theater which must buy thousands and maintain them, while facing the constant risk of theft, it’s impractical.

• Position and tilt can affect the image. I’m not sure about this one, but it seems that the LCD shutters refresh from the top down, like your monitor. It’s not done all at once, technically speaking.

This can be predicted for or ignored when the head is straight, but when there is tilt, you can get bleed of certain portions of the other eye’s image, or a prismatic effect from the LCDs not being aligned correctly with the screen. There can also be interference from the refresh pattern of the LCD. Plasmas reduce this.

• Power is required. LCDs don’t run on faith. The batteries in these things need charging, not particularly frequently, but infinitely more so than passive glasses. Furthermore, the machinery and power infrastructure means they can be bulky and heavy, though this is improving.

• A “frequency arbiter” is often required. Until some serious standards are established, it’s unlikely that your glasses, Blu-ray player or set-top box, and TV will all be speaking exactly the same language. And since absolute precision is necessary for the glasses to work correctly (the error must be kept down to fractions of a microsecond), and tiny variations may occur somewhere along the line, a synchronizing device is often used to coordinate the signals from the other components of the display. These increase the cost of the system and are one more thing to break or replace.

• The flashing LCDs have been linked to epileptic seizures, among other things. I’ll go into this further below in “dangers,” but for now it’s enough to know that the risk exists.

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Autostereoscopic display - http://www.crunchgear.com/2010/06/19/a-guide-to-3d-display-technology-its-principles-methods-and-dangers/ A guide to 3D display technology: its principles, methods, and dangers

by Devin Coldewey on June 19, 2010

http://nextgenlog.blogspot.com/2010/05/3m-conquers-3.html

These have been around for a while, at various levels of sophistication, and are now in the spotlight as the 3D method used by the Nintendo 3DS. You probably saw something of the lenticular lens method (a sawtooth prism that directs light in varying direction) in “holographic” display in the 90s on a fancy CD jewel case covers (I remember it from Tool’s Aenima (yeah yeah)). The principle is that by some method or another, one pixel or group of pixels has its light directed to one eye, and another group to the other. This can be accomplished in a number of ways, but nowadays it is most likely to be a parallax barrier: a series of slits in the display, precisely placed to allow light from every other line of pixels to go one way or the other. Even lines of pixels go right, and odd lines go left, for instance. This enables the image to be split without the use of glasses — a benefit not to be underestimated.

As you might expect, there are issues with this method as well.

• There’s a relatively small “sweet spot.” Because the placement of the slits (and therefore the viewable angle of the affected lines of pixels) is static, you must have your eyes in a certain place in order to perceive the effect. Too close or too far away and light begins to leak in from the other set of pixels, or the 3D illusion is destroyed otherwise.

• Effective resolution and brightness are halved. Because half of the lines are going one way and half the other, each eye receives half the information that the screen is capable of putting out. This results in reduced brightness and resolution. The 3DS’s screen is 800×240, but the effective resolution is 400×240 (giving it a weird aspect ratio somewhere between 16:9 and 16:10, incidentally). If you want to display 1080p content using a parallax barrier, you need a 4K display.

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It requires modification of existing screens. Although I can imagine a parallax barrier filter for a TV, it’s never going to happen. The technology must be tightly integrated with the display, which increases cost. It’s also possible that the parallax grill might be variable on large TVs with wide pixel pitch.

http://www.3d-forums.com/autostereoscopic-displays-t1.html Autostereoscopic displays are able to provide binocular depth perception without the hindrance of specialised headgear or filter/shutter glasses. The technology has existed for many years, and has been used to provide stereoscopic vision in research environments since the 1980’s.

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Autostereoscopic displays fool the brain so that a 2D medium can display a 3D image by providing a stereo parallax view for the user. This means that each eye sees a different image, having been calculated to appear from two eye positions. These stereoscopic displays lack several other cues that are normally used to build up a 3D image: • Movement Parallax – the infinite number of images that can be seen as viewing position is moved around the object. An autostereoscopic display only has a single 3D view which has been calculated by the software.

• Convergence – the natural way eyes will converge on an object. On an autostereoscopic monitor they are converging in front or behind the monitor on a virtual object.

• Accommodation – the focusing of each eye on the object. This is at a different distance on an autostereoscopic display as the display and virtual object will be at different distances from the user.

• The two main methods for providing autostereoscopic vision are the parallax barrier and Lenticular lens:

Method of operation for an autostereoscopic parallax barrier.

In the parallax barrier a mask is placed over the LCD display which directs light from alternate pixel columns to each eye. Parallax barrier displays allow instant switching between 2D and 3D modes as the light barrier is constructed from a layer of liquid crystal which can become completely transparent when current is passed across, allowing the LCD to function as a conventional 2D display.

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e-Paper & e-Books Method of operation for an autostereoscopic lenticular lens.

In the lenticular lens, an array of cylindrical lenses directs light from alternate pixel columns to a defined viewing zone, allowing each eye to receive a different image at an optimum distance.

Both of these methods provide a restrictive view but it would be possible to view an image continuously across the viewing zones if head/eye tracking technology is used. Once the users eye passes from one image band into another the image would usually invert, however if the images shown to each side of the zone are flipped once the eye passes the barrier it is possible to create a continuous image. This will not provide motion parallax as the image view would remain the same but it would make it easier to hold focus of the image.

Correct viewing position of an autostereoscopic display.

In the example shown above, three users are seen to be viewing an autostereoscopic monitor. The user to the right (“Inverse Image”) is aligned incorrectly and the image formed at each eye is the wrong way round.

The “blended zone” user is standing too far away from the optimal distance datum and is seeing both images forming in each eye, causing a blurred and confusing image. The user in the centre is standing in the correct position, with each eye located within the correct viewing zone. Note that if this was a head tracking monitor and the viewers were in an inverse image zone, the monitor could switch the images being projected in each direction. However, for practical implementation of this switching process, it would need to be demonstrated that repeated traverses into and out the inverse image zone would not lead to flicker.

In order to simulate motion parallax a multiview autostereoscopic monitor must be used, which is a much more complex and costly device. It does not provide full motion parallax but a number of viewing angles can be provided (9 and 16 are common values). Multiview screens do not require head tracking, but do require a lens array to project all the views at once. As the user moves from left to right the viewing zones will transition through each viewing angle, however the processing behind the monitor will still have to project each image stream. This will not only require much more computing power, but may also reduce the resolution if monitor is used as the projecting device as the horizontal resolution is shared across each viewing angle.

□□□□□ - http://www.tomshardware.com/reviews/3d-stereo-technology,1023-6.html May 2005 by Lars Weinand

As the name implies, autostereoscopic displays can create a 3D effect without having to rely on any extra devices like shutter glasses. The manufacturers attempt to use optical tricks to aim the waves of light emitted by the monitor directly at the viewers eyes. If the viewer's head is within a certain area in front of the screen, the so-called stereo zone, the scene will appear to be in 3D. In this case, the effect is achieved with a normal TFT display that has been adapted by adding a "lens plate" designed and manufactured specifically for this one model. The lenticular lenses refract the light in such a way that each of the viewer's eyes only sees one row of pixels. For example, the left eye would see all evennumbered lines, while the right eye sees the odd-numbered ones. Appropriate software then arranges for the stereoscopic image output. The result is that the viewer can now see a real, 3D environment when situated within a certain area before the screen, without the need for any extra devices.

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The rows of pixels are split up. The even-numbered rows display the image for the left eye, while the oddnumber show that for the right eye.

A thin sheet of plastic explicitly designed for a certain display carries rows of vertically aligned lenticular lenses. These refract the light directly towards the eyes of the viewer.

This creates a "stereo zone" in a narrowly defined area in front of the display in which a stereoscopic depiction is possible.

Unfortunately, even this 3D stereo technique has its drawbacks. First, it suffers from a reduced horizontal resolution. An autostereoscopic display with a native resolution of 1600x1200 effectively only has 800x1200 pixels, since each eye only sees every other pixel. The brain then combines these two half-images to form the stereoscopic image, but that doesn't change the fact that the resolution of the image is lower. Next, this type of display is inherently incapable of displaying any kind of 2D image, as the lenses always refract the light into a stereoscopic image. The third big disadvantage is the size of the defined stereo zone; if the viewer moves outside of the area, the image becomes inverted - hills become valleys, and vice versa.

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e-Paper & e-Books - http://vmlab.kz.tsukuba.ac.jp/3d/Autostereoscopic%203D%20Workbench%20Project.htm We are developing human computer interaction system based on the autostereoscopic displays. For smooth interaction with 3D space generated by the computers, we have developed a new autostereoscopic display which presents computer generated 3D image with unprecedented reality within the viewer's reach.

Enhancement of reality within the viewer's reach is essential to create the direct manipulation system where the viewer can feel as if he or she is manipulating the virtual 3D space controlled by the computers directly with their hands. Therefore our display can be a powerful tool to create various human-computer interaction systems, such as 1. Interactive Visualization (for education, entertainment, etc.)

2. 3D Drawing (for design, education, etc.)

3. Handwork Simulator (for medical surgery training etc.)

VIDEO http://vmlab.kz.tsukuba.ac.jp/3d/video.mpg The autostereoscopic 3D display we have proposed consists of Fresnel lenses, a screen which shows two differently polarized images, polarizing filters mounted on a mobile stage, a head-tracking device, and a computer that controls these devices. The feature of the proposed system is that it generates a real image in front of the viewer, which reduces contradiction between the focus information and the parallax information when a 3D image is to be presented near the viewer.

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The proposed system can be used as an autostereoscopic 3D workbench where viewers can interact with 3D images directly with their hands without suffering from the severe eyestrain caused by the great contradiction between focus and parallax in the conventional display systems

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Acronyms See also Nanotechnology vol.1 Transparent & flexible electronics www.biodomotica.com/public/foldable_world.pdf AMLCD: AMOLED: BiNem: BLU: Ch-LCD: CSTN:

Active-matrix liquid-crystal display Active-Matrix OLED Bistable Nematics Flexible LED backlighting unit Cholesteric LCD also-known-as “chiral nematic liquid crystals” Color Super-twist Nematic, and LCD technology developed by Sharp Electronics Corporation.

Unlike TFT, CSTN is based on a passive matrix, which is less expensive to produce. The original CSTN displays developed in the early 90's suffered from slow response times and ghosting.

Recent advances in the technology, however, have made CSTN a viable alternative to activematrix displays. New CSTN displays offer 100ms response times, a 140 degree viewing angle, and high-quality color rivaling TFT displays - all at about half the cost. A newer passive-matrix technology called High-Performance Addressing (HPA) offers even better response times and contrast than CSTN. DPI: Dots per inch DRM: An acronym for Digital Rights Management (or sometimes referred to as Digital Restriction Management). DRM refers to the technology to control the access to digital media or devices, e.g. the e-books and e-readers. It prevents the copying and conversion of digital media into other formats by end-users or limits the access as defined by publishers or copyright holders.

DSTN: Double-layer Super-twist Nematic, a passive-matrix LCD technology that uses two display layers to counteract the color shifting that occurs with conventional supertwist displays EC display: Electrochromic displays ELP: Electronic Liquid Powder EMR: Electro-Magnetic Resonance http://www.wacom-components.com/english/technology/index.html EPD: Electrophoretic displays EPOP Electronic Point of Purchase ePub Electronic PUBlishing - An open standard for electronic books FED: Field Emission Display also-known-as Nano-emissive displays (NEDs) FPD: Flat Panel Display HD: High Definition HDMI: High Definition Multimedia Interface HPA: High-Performance Addressing an passive-matrix display technology the provides better response rates and contrast than conventional LCD displays. Although HPA displays aren't quite as crisp or fast as active-matrix TFT displays, they're considerably less expensive to produce.

Consequently, HPA is being used by a number of computer manufacturers for their low-end notebook computers.

IMOD: Interferometric Modulator. Qualcomm’s low-power technology for flat panel displays for mobile devices. Combines ultra-thin film optics with a micro-electro mechanical system (MEMS) device to create displays viewable in any lighting condition.

IPS: In-Plane Switching - LCD LCD: Liquid Crystal Display LED: Light-Emitting Diode LPI: Lines Per Inch MEMS: Micro-Electro Mechanical Systems. A technology that combines computers with tiny mechanical devices (such as sensors, valves or gears) for integration with integrated circuits. MEMS devices refer to mechanical components that are one micrometer (one millionth of a meter) in size http://en.wikipedia.org/wiki/MEMS Nematics Of or relating to the mesomorphic phase of a liquid crystal in which the molecules are oriented in loose parallel lines NCD: NanoChromic Display OLED: Organic Light-Emitting Diode OTFT: Organic thin film transistors PEDOT: Polyaniline and polyethylenedioxythiophene are examples of electrochromic materials PDP: Plasma display panel P-Ink Photonic ink is a substance that can display any color value in the spectrum Pixel: Picture Element POP: Point-of-Purchase PLED: Polymer Organic Light-Emitting Diode PPI: Pixels per inch (pixel density or pitch) or PPI (Point Per Inches) 172 Massimo Marrazzo - biodomotica.com

e-Paper & e-Book PVI: QD LED: QLED: QR-LPD: REED: SDC: SED: SPI TFT:

ZBD:

Prime View International Quantum dot display Quantum dot display Quick Response Liquid Powder Display Reverse Emulsion electrophoretic Display Segmented Display Cell Surface-conduction Electron-emitter Display Samples per inch Thin Film Transistor. The term typically refers to active matrix screens on laptop computers.

Active matrix LCD provides a sharper screen display and broader viewing angle than does passive matrix http://encyclopedia2.thefreedictionary.com/TFT Zenithal Bistable Display

OLED Glossary AMOLED: FOLED: IOLED: NOID: PHOLED: PLED: PMOLED: POLED: RCOLED: SMOLED: SOLED: TOLED:

Active Matrix OLED Flexible OLED Inverter OLED Neon Organic Iodine Diode Phosphorescent OLED Polymer Light Emitting Diode Passive Matrix OLED Polymer OLED Resonant Color OLED Small Molecules OLED Stacked OLED Trasparent Organic Light Emittign Device

Wireless Glossary: http://www.qualcomm.com/products_services/glossary/ 3G Third Generation wireless technology. Based on digital technology, 3G wireless networks offer increased voice capacity and provide higher data rates than 2G and 2.5G networks. As defined by the International Telecommunications Union (ITU), 3G technology has been or will be implemented as CDMA2000, CDMA2000 1xEV-DO, WCDMA/UMTS and HSDPA/HSUPA. 802.11 - a.k.a. Wi-Fi 802.11 refers to the body of standards issued by the IEEE for WLANs (wireless local area networks). 802.11 technologies use an over-the-air interface to connect a device (for example, a Wi-Fi-enabled laptop) and an access point to another network. The 802.11 family of technologies includes 802.11a, 802.11b, 802.11g and 802.11n.

Bluetoothâ&#x201E;˘ A short-range wireless technology that interconnects devices such as phones, computers, keyboards, microphones and mice. Bluetooth supports both voice and data communications. bps Bits Per Second. The standard for measuring the smallest unit of information in digital communications and data processing.

Broadband Generic term for high-speed digital Internet connections, such as wireline, DSL or cable modems and wireless third-generation technologies, such as WCDMA (UMTS ), CDMA2000 1xEV-DO and HSDPA .

Cellular Analog or digital communications that provide a consumer with a wireless connection from the mobile device to a relatively nearby transmitter (base station). The transmitterâ&#x20AC;&#x2122;s coverage area is called a cell.

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e-Paper & e-Books EDGE Enhanced Data Rates for Global Evolution. A software/hardware enhancement for existing GSM networks designed to provide higher data rates to enhance the delivery of multimedia and other broadband applications for wireless devices.

GB Gigabyte. A measure of computer data storage capacity. Measured as approximately a billion bytes or 1,073,741,824 in decimal notation.

GHz Gigahertz. A measure of frequency equal to a billion hertz or a thousand megahertz (MHz). Gigahertz is often used to measure UHF (ultra-high frequency) or to express microprocessor clock speed in some computers.

GPRS General Packet Radio Service. A 2.5G technology standard that is an upgrade to a GSM network. Adds packet data to the existing voice network.

GPS Global Positioning System. A worldwide radio-navigation system developed by the U.S. Department of Defense to enable users to determine their exact location anywhere on the globe from land, air or sea. GPS works via radio signals sent from orbiting satellites to receivers on the ground. GPS receivers are used in a wide range of commercial applications from fleet management to rural navigation.

GSM Global System for Mobile Communications. A second-generation wireless telecommunications standard for digital cellular services first deployed in Europe. GSM is based on TDMA technology and provides circuitswitched data connections.

Hertz The international unit for measuring frequency, equivalent to cycles per second. One megahertz (MHz) is one million mertz. One gigahertz (GHz) is one billion hertz.

HSDPA High-Speed Downlink Packet Access. An enhancement to WCDMA networks that provides higher data speeds in the downlink to support applications such as VPN access, video downloads and large file transfers.

IEEE Institute of Electrical and Electronics Engineers. A standards body responsible for developing computing and electronics standards. The IEEE developed 802.11 standards for WLANs (wireless local area networks) that are widely followed today.

KB Kilobyte. A measure of computer memory or storage. Measured as 1,024 bytes in decimal notation.

Kbps Kilobits per second. Commonly used as a speed for data transmission. Measured as 1,000 bits per second.

Kilohertz (KHz) One thousand hertz. A measurement often used to reference radio frequencies.

LAN Local Area Network. A small communication network covering a limited area, such as within a building or group of buildings.

Mbps Megabits per second. Measured as one million bits per second. A measurement of the amount of data transferred in one second between two telecommunication points.

MHz Megahertz. One million hertz or cycles per second. A measurement often used to describe the speed of digital and analog signals.

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e-Paper & e-Book RF Radio Frequency. Measured in Hertz, MHz and GHz. Wireless and cordless telephones, radio and television broadcast stations, satellite communications systems and two-way radio services all operate using radio frequencies.

RFID Radio Frequency Identification. A method of remotely retrieving data from and storing data associated with animals, people, products or equipment. Requires an RFID tag which contains an antenna to enable the tag to send and receive queries from an RFID transceiver.

RFID Tag Radio Frequency Identification Tag. A small radio frequency device used to identify and track people, animals, commercial products or corporate assets UMTS - a.k.a. WCDMA Universal Mobile Telecommunications System. A third-generation (3G), CDMA-based wireless communication standard that offers enhanced voice and data capacity and higher data rates than previous, second generation wireless technologies.

WCDMA - a.k.a. UMTS Wideband CDMA. A third-generation (3G), CDMA-based wireless communication technology that offers enhanced voice and data capacity and higher data rates than previous, second-generation wireless technologies.

Wi-Fi Short for “Wireless Fidelity” and another name for WLAN (wireless local area network). Allows a mobile user to connect to a local area network (LAN) through a wireless connection. Wi-Fi has been deployed in airports, universities, bookstores, coffee shops, office campuses and private residences.

WiMAX Wireless Interoperability for Microwave Access. A group of proposed wireless standards for high-throughput broadband connections over long distances. Applications include “last mile” broadband connections and hot spots. Trade name for a new family of IEEE 802.16 wireless standards.

Links see also Nanotechnology vol.1 Transparent & Flexible electronics www.biodomotica.com/public/foldable_world.pdf http://www.epapercentral.com http://www.electronicbookreaders.co.uk/compare-ebook-readers compare e-book readers http://www.whizebook.com/2008/03/list-of-all-ebook-readers.html list of e-book readers http://store.simplicissimus.it/ compare and buy e-book readers (Italian)

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BIODOMOTICA Massimo Marrazzo www.biodomotica.com info@biodomotica.com

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