LCD TV

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 sandwiching 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 aren’t completely opaque to light, however; some light will always penetrate even the blackest LCD pixels.

Liquid crystal display television (LCD TV) is a television using LCD technology for its visual output. This technology is generally TFT. It is contrasted to alternate visual output technologies, such as cathode ray (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 looking straight 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.

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 Sharp Corp. Sony, Samsung, LG Philips and others.

Modern LCD TV sets are geographically universal because they have a multisystem tuner, to display PAL, NTSC and SECAM norms. And they include an electronic (step-down & step-up) transformer that automatically can use 110/250 V AC indifferently and universal grounded adapter plugs.