QandAs: Tech

What is an LCD TV?

Answer:
A LCD TV uses liquid crystal diodes or thin-film transistors

(TFTs) to produce an viewable television image on a flat screen. Many electronics consumers are now choosing between LCD and plasma televisions to support high-definition television broadcasts and computer images.

An LCD TV uses the same technology as a TFT monitor screen found in many laptop computers. Two thin screens are sandwiched together with a layer of liquid crystal material between them. One screen is polarized to display horizontal information, while the other is polarized to display vertical information. When electrical current is introduced, the liquid crystals act like miniature blinds, either blocking or allowing white light to pass through the matrix. The white light of an LCD TV is provided by a diffused bulb placed behind the screen.

A LCD TV has significantly better picture quality than a standard cathode ray tube (CRT) because there are far more individual picture elements, or pixels. Each pixel contains red, blue and green subpixels which are filtered out of the white light to create a color image for the viewer. The image of a red apple on an LCD TV screen, for example, is created by filtering out the blue and green subpixels, leaving the proper red color.

LCD televisions can have a flat monitor screen with a matrix of liquid crystals or a larger screen with a projected image generated by LCDs. This allows LCD TVs to compete with large plasma televisions for the home theater market. LCD televisions can also be found on commercial airliners, since the liquid crystals are not affected by external air pressure. An LCD TV is generally less expensive than a plasma television, although some critics suggest that plasma televisions deliver more color saturation and higher definition than many current LCD televisions.