What is LCD TV & LCD Teconology ?

Liquid crystal display television (LCD TV) is television that uses LCD technology for its visual output. The technology used is generally TFT. It differs from alternate visual output technologies, such as cathode ray tube (CRT) or plasma display (PDP TV).

Early LCD television had drawbacks relative to traditional visual display technologies. It displayed fast-moving action with "ghosting" and could be viewed best only when looking directly at the screen or from a slight angle. These problems have largely been overcome in recent years, and LCD televisions, along with plasma displays, have taken over the dominant market position worldwide from cathode ray displays. The LCD design has the additional advantage of being more efficient in the use of electricity than the CRT design.

For a long time it was widely believed that LCD technology was suited only to smaller sized televisions, and could not compete with plasma technology at larger sizes. This belief has been undermined by the announcements of seventh-generation panels by companies such as Samsung, Sony, LG-Philips LCD, Westinghouse Digital, and Sharp Corporation:LCD technology is based on the properties of polarized light. Two thin, polarized panels sandwich a thin liquid-crystal gel that is divided into individual pixels. An X/Y grid of wires allows each pixel in the array to be activated individually. When an LCD pixel darkens, it polarizes at 90 degrees to the polarizing screens.

This cross-polarizing blocks light from passing through the LCD screen where that pixel has darkened. The pixel darkens in proportion to the voltage applied to it: for a bright detail, a low voltage is applied to the pixel; for a dark shadow area, a higher voltage is applied. LCDs are not completely opaque to light, however; some light will always go through even the blackest LCD pixels.