what difference between TFT and LCD ( lichid cristal display ) screen?

Answer 1

TFT: Thin Film Transistor is a type of screen on which the viewing anle is maximum.The viewing angle will be as much as a normal CRT screen.
LCD:Liquified Cristal Display consists of two screens sandwiched with the Liquid crystal. The viewing angle is very less

Answer 2

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 ever-larger panels by companies such as Sharp Corporation, Samsung, Sony, Westinghouse Digital, and LG.Philips LCD:

In October 2004, 40" to 45" televisions were widely available, and Sharp had announced the successful manufacture of a 65" panel.
In March 2005, Samsung announced an 82" panel.[1]
Manufacturers have announced plans to invest billions of dollars in LCD production over the next few years, with televisions expected to be a key market. (The other main market for LCD displays is in computer monitors.)
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
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A thin film transistor (TFT) is a special kind of field effect transistor made by depositing thin films for the metallic contacts, semiconductor active layer, and dielectric layer. Anne Chiang, a Taiwanese-American, among many others, is credited with major advances in the development of TFT technology [1].

The channel region of a TFT is a thin film that is deposited onto a substrate (often glass, since the primary application of TFTs is in liquid crystal displays).

Most TFTs are not transparent themselves, but their electrodes and interconnects can be. The first transparent TFTs, based on zinc oxide were reported in 2003 by researchers at Oregon State University.

The best known application of thin-film transistors is in TFT LCDs, a variant of LCD technology. Transistors are embedded within the panel itself, reducing crosstalk between pixels and improving image stability. As of 2004, all but the cheapest color LCD screens use this technology