LCD Televisions - Revolutionizing Visual DisplayWhat does LCD stand for? LCD is an abbreviation for Liquid Crystal Display. Liquid Crystal Display is being used in digital clocks, microwave ovens, car dashboards, calculators, stereos, thermometers and bathroom scales. Today, this is a technology that is increasingly being used in the manufacture of both computer and television monitors. Television units manufactured using this technology is referred to as LCD Televisions. Early television used a technology known as CRT or Cathode Ray Tube. This tube consisted of an evacuated glass envelope containing an electron gun and a fluorescent screen. The electron beam was deflected and modulated using this device to display images on the screen. It was the shape of the tube in the early monitors which made televisions so bulky at the back! Liquid Crystal Display technology in LCD Televisions uses polarized light to display images. A thin liquid crystal gel divided into individual pixels is sandwiched between two polarized panels and X/Y grids of wires activate the pixels individually. To darken the screen, the LCD pixel is polarized at 90 degrees to the polarizing panel in proportion to the voltage applied to it. The lower the voltage applied the brighter the detail. The flatness of the polarizing panels has resulted in a television monitor that is flat like a picture frame!
It was initially believed that LCD technology can be used only in the production of small LCD Televisions and could not compete with the large Plasma display screens. It was also contended that since transmission of high speed images caused ghosting, the LCD Televisions are not as effective as the traditional CRT monitors. However, the improvement in LCD technology in LCD Televisions has eliminated almost all the problems that were associated with this technology in the early years of development. Today, LCD Televisions compete with Plasma flat panels and rear projection television technology (used for High Definition Television (HDTV)) and even have certain advantages over them. Eighth generation LCD Televisions have been announced by Samsung, Sony, LG Phillips LCD, and Sharp Corporation and they see a hug market for their television monitors. LCD televisions deliver a broad angle of view (max 178 degrees) and a contrast ratio for viewing bright scenes and dark scenes in bright rooms. A dynamic contrast technique or an alternate technique of throwing light on the wall behind the screen is used to help the ratio of brightness and contrast in the display. PVA and S-PVA panels used for this purpose may cause ghosting when transitioning between scenes but this is compensated by using a technique called overdriving (for black to gray and gray-to-gray transitions) and shortening the response time through improved panel design. Some LCD Television manufacturers have attempted to double the refresh rate of the LCD panel and reconstruct the intermediate frames using motion compensation techniques. Other manufacturers have combined the two techniques above to get the best possible results from their LCD Televisions. Modern LCD Televisions deliver all sRGB colors using a combination of backlight's spectrum and optical filters, but the effort is to make these monitors deliver more colors by using the fourth, fifth or even sixth color in the optical color filter array or use two narrowband backlights with differing colors in combination with optical filters in a panel to deliver a larger kaleidoscope of colors. Modifications to the distribution channel are also being explored in this context. So, it is not surprising that LCD Televisions now bring a lot to the quality of TV time. First it is easy to watch as LCD Televisions function very well in ambient light conditions. You do not have to worry about eyestrain as there is no flicker. The angle of viewing is so wide that you can sit anywhere in the room and watch the TV. The higher the dot pitch (the closeness of the pixels in the screen) of the screen the better will be the resolution of the picture and the breadth of the angle of viewing. As each subpixel has its own transistor electrode the picture will be smooth and evenly lit across the surface of the display. The tuner and speakers built into the television set will enable you to watch the TV right out of the box!
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