Large Displays for Domestic Use

Large Displays for Domestic Use

Large Displays for Domestic Use Introduction *LCD*s Voltage is applied to control the amount of light passing through liquid crystal molecules, which form an array of cells known as pixels. {draw:frame} Figure 1: LCD technology Some advantages of LCDs include good color reproduction, improving contrast and perfect sharpness at native resolution. Physically they are very thin and relatively lightweight with flexible mounting options. LCDs have low power consumption and excellent longevity. Some disadvantages are slow response times resulting in severe motion artifacts and image degradation for moving or rapidly changing images. Also LCDs must be viewed as close to straight ahead as possible due to limited field of vision. Although their cost is rapidly decreasing some of the larger displays can be very expensive. New materials and novel device concepts are continually emerging such as electrically sensitive materials called ferroelectric and antiferroelectric liquid crystals. Some LCD screens incorporate a thin film transistor (TFT) in each pixel to drive the display. Those devices are widely used in the laptop computer screens. Manufacturers are looking to make LCD screens thinner, bigger, faster and cheaper. In newer models the blurring is greatly reduced and the black levels are being improved. They give brighter images from all angles. Plasma displays Plasma screens are made up of red, green and blue phosphors forming a pixel, which is mounted between two thin layers of glass. An electric pulse excites the rare natural gases argon, neon and xenon used to produce the desired colour. These gases actually have a life and fade over time. All the phosphor-excited pixels react at the same time. There is noflicker apparent to the viewer, no backlight and no projection of any kind. {draw:frame} Figure 2: Plasma display technology Plasma displays have excellent colour reproduction and contrast ratios. They have perfect viewing angle and long...

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