TECHNOLOGY
plasma or LCD?
don’t fall flat... The Kudos Guide to Buying A New TV
It’s official: cumbersome, awkward CRT televisions (that’s fat TVs with electron guns inside to you and me) are over. Sony and Panasonic have already halted production of traditional cathode ray tube TVs and, at the time of going to press, Samsung have not re-released their last CRT model for 2008; with this in mind, it’s time to go High-Definition ready, flat-screen. To help us take this exciting step forward Kudos enlisted the help of Sevenoaks Hifi to make the big choice: Plasma or LCD?
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TECHNOLOGY
the science The name refers to the plasma formed by the two gases (xenon and neon) held inside the screen; these gases are trapped in minuscule cells, which are held between two panes of glass. The plasma created by the gases is attracted to electrodes in the screen, forming submicroscopic beams of atomic energy. The front panel of the screen is covered in a substance called phosphor, which is divided into red, blue and green cells. The phosphor glows when exposed to the atomic beams, thus creating light. The combination of one bank of three cells – individually covered in the red, blue and green phosphors – creates one pixel on the display of your television. Imagine this pattern recreated 1280 times and you have the image displayed by a typical plasma television.
pros •
STUNNING PICTURE
plasma cons •
Because of the phosphorous light display, plasmas create a very bright picture that generally does not reduce in quality as the size of the screen increases •
SHORTER LIFESPAN It has been claimed that significant technological advances have put this reputation to bed, but the cheaper plasma models will still tend to have a shorter lifespan than LCD equivalents
GREAT ANGLES The distribution of gases throughout the whole screen means that a plasma image is clear from every viewing angle
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SCREEN BURN-IN The constant display of images like browsing menus can cause these images to become imprinted within the display, because one area of the phosphor-covered screen is used more than others
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TECHNOLOGY
the science
LCD pros •
THE SMALLER, THE BETTER
cons •
The nature of the liquid crystal technology means that expansion to larger sizes is a difficult process, but it does mean that the picture on smaller LCDS can be better than on plasma equivalent •
ECO-FRIENDLY The use of a backlight significantly lessens the power consumption of the LCD TV; they can consume up to 60% less power than a traditional cathode ray tube television
AWKWARD PICTURE Each pixel is an image that needs to be electronically refreshed, and on some models this process does not happen quickly enough; this can result in fast action on screen getting lost
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PIXEL FAILURE Like any small electrical connections with operating switches and gates, the circuits controlling individual pixels can fail, leaving ‘dead’ pixels
LCD, or Liquid Crystal Display, is a technology that has long been in use for electronic watches, calculators and clocks. Each element of an LCD display is created by liquid crystal molecules being electronically aligned by electrodes. Because the crystals are liquid they can bend – or refract – light in order to provide a variety of contrast; filters on either side of the crystals provide a spectrum for the light, which is provided by a backlight. Television displays take this principle of light manipulated by electrified liquid crystal and add layers of complexity. In an LCD TV display, each pixel on screen is a minute glob of liquid crystal that is controlled by a grid of intersecting electronic connections. Each pixel inside its electrified box can be individually controlled by a transistor, to allow more or less light through in different shapes and patterns, thus creating an image.
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• SEVENOAKS HI FI RECOMMEND MODEL: xxx xxx xxx
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