What Is E-Paper Display?

How Does It Work?

Contributed by Ynvisible

Electronic paper, or an e-paper display, has many benefits over traditional display technologies like LCD and LED. As a result, e-paper display technology is widely used across different sectors. But, what is e-paper display technology and how does it work? In this article, we will look at how electronic paper works and its advantages.

What Is E-Paper?

E-paper displays can be made using different types of technology, such as electrophoresis, electrowetting, and electrochromism [1]. At Ynvisible, we use electrochromism, as it allows us to use highly scalable, flexible, and cost-effective screen-printing production processes, whereas some display companies, such as E Ink, use electrophoresis (see below).

Electronic paper or e-paper is a display technology that mimics the appearance of ordinary ink on paper to produce a low-power, paper-like display. E-paper displays typically have a so-called image memory, which means they do not need much power to maintain the display; they mostly need power when there is a change in the display. Therefore, e-paper displays are best for low-frequency switching displays, such as signage and labels. E-paper displays reflect light rather than emit light, making them very comfortable to read even under direct sunlight. They are extremely popular because of their low power consumption, high reflectivity, high contrast, readability, thickness, and wider viewing angle. E-paper displays are widely used in e-readers, real-time bus arrival information, electronic shelf label (ESL) segments, digital menu boards, traffic signs and logistics monitoring devices.

How Does E-Paper Work?

Several e-paper technologies create e-paper displays, and each works differently.

Electrophoretic Displays (e.g., E Ink) Electrophoretic displays from, for instance, E Ink, contain millions of tiny microcapsules. These microcapsules are filled with a clear fluid having small particles of different colors and electric charges. On applying a positive charge, negatively charged particles move to the top, and positively charged particles move to the bottom of the microcapsule and vice versa. This movement of the particles to the top and bottom makes the surface display a specific color.

Electrowetting Displays (e.g., Etulipa) Etulipa is one of the companies employing electrowetting display technology, which uses the liquid’s surface tension to create electrowetting displays. An electrowetting display contains several tiny cells of transparent polar liquid and a colored oil covering a hydrophobic surface. The oil contracts into a small droplet by applying a low voltage to the cells. It then creates an open or closed optical switch capable of displaying text, art, photos, or even video.

Figure 1: Ynvisible’s displays are produced using processes that are highly scalable and cost-effective. Figure 2: Ynvisible’s displays are flexible and lightweight. Figure 3: The most popular application of e-paper is e-readers.

Electrochromic Display (e.g., Ynvisible) Electrochromic displays are produced using electrochromism, a process where material changes color when applying an electric current. The electrochromic material undergoes chemical oxidation and reduction on applying voltage in the presence of an electrolyte. This results in a color change, which can be finely tuned. Ynvisible’s electrochromic displays are ultra-energy-efficient, and one coin cell battery can power them for around 50 years.

Ynvisible’s displays are produced using screen-printing processes that are highly scalable and cost-effective (see Figure 1), making them a more cost-effective solution to other e-paper technologies.

Key Features of E-Paper

The five key features of e-paper technology are:

1. Bistability E-paper displays have various levels of bistability, which means that the display retains an image without requiring a power source. Ynvisible displays can retain an image for 15 minutes before a small refresh pulse is required. We call this semi-bistability.

2. Low Power Consumption Since e-paper displays do not need any backlight nor power to retain an image, these displays have extremely low power consumption, making them ideal for off-grid applications, for example.

3. Reflectiveness E-paper displays reflect light; they do not emit any light, making them incredibly energy-friendly. This also makes these displays ideal for reading in direct

Figure 4: Electronic paper is perfect for digital signage and public information displays. Figure 5: E-paper displays are widely used in supply chain management to track and monitor goods in real-time.

Figure 6: E-paper can also be used to counter the piracy of products. Figure 7: Electronic paper displays provide a cheaper alternative to traditional paper label methods.

sunlight, a common flaw found with other display types.

4. Readability E-paper displays have excellent readability because of their wider visibility angle and high contrast, making them ideal for important announcements, such as traffic updates.

5. Flexibility Some e-paper displays are used because of their high flexibility (Ynvisible’s displays are flexible enough to curve around a pencil!) and lightweight nature (Figure 2). This is a really important factor when shipping is involved, for example.

Ynvisible’s e-paper displays [2] are also fully customizable and can be developed to meet your exacting brand requirements.

E-paper displays have been around for many years now. E-paper display mainly started off being used in e-book readers but has found use in many more applications across different industries due to its low-power, low-weight and flexible properties (Figures 3 to 7) [3][4].

Get started with Ynvisible’s e-paper displays today with our E-Paper Display Kit [5] — it’s the best way to trial the technology and work out if it’s right for you. Interested developers will find informations about driving the displays at [6].

220273-01

WEB LINKS

[1] What Is Electrochromic Display Technology?: www.ynvisible.com/news-inspiration/what-is-an-electrochromic-display [2] Cost-Effective Custom Display Prototypes: www.ynvisible.com/news-inspiration/cost-effective-custom-display-prototypes [3] Anti-Counterfeit & Authenticity Solutions Using Printed Electronics: www.ynvisible.com/news-inspiration/authentication-solutions-printed-electronics [4] New Cost-Effective Display Applications: www.ynvisible.com/solutions [5] E-Paper Display Kit: www.ynvisible.com/product/e-paper-display-kit [6] How to Drive Ynvisible’s E-Paper Display: www.ynvisible.com/news-inspiration/how-to-drive-ynvisible-e-paper-display