flat-panel display

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Flat panel TVs have existed since 1964, and are much thinner and lighter than televisions with picture tubes.

Flat panel displays (sometimes referred to as flatscreens, which more technically mean screens with fully flat front surfaces) encompass a growing number of electronic visual display technologies. They are far lighter and thinner than traditional television sets and video displays that use cathode ray tubes (CRTs), and are usually less than 10 centimetres (3.9 in) thick. They can be divided into two general display technology categories: volatile and static.

The first engineering proposal for a flat screen TV was by General Electric as a result of its work on radar monitors. There publication or their findings gave all the basics of future flat screen TVs and monitors. But GE did not continue with the R&D required and never built a working flat screen at that time.^[1]

The first-ever flat panel display was invented in 1964 at the University of Illinois.^[2] The first-ever active-matrix addressed display was made by T Peter Brody's Thin-Film Devices department at Westinghouse Electric Corporation in 1968.^[3]

In many applications, specifically modern portable devices such as laptops, mobile phones, digital cameras, camcorders, point-and-shoot cameras, and pocket video cameras, any display disadvantages are made up for by portability advantages.

Most of the modern flat-panel displays use LCD technologies. Most LCD screens are backlit to make them easier to read in bright environments. They are thin and light. They provide better linearity and higher resolution.

Common types

Liquid crystal panels

Liquid crystal displays are lightweight, compact, portable, cheap, more reliable, and easier on the eyes than CRTs. A thin layer of liquid crystal, a liquid that exhibits crystalline properties, is sandwiched between 2 electrically conducting plates.The top plate has transparent electrodes deposited on it, and the black plate is a mirror. By applying proper electrical signals across the plates, various segments of the liquid crystal can be activated, causing changes in their light diffusing or polarizing properties. These segments can either transmit or block light. An image is produced by passing light through selected segments of the liquid crystal and then reflected it back from the mirror to the viewer. They are used in various electronics like watches, calculators, and notebook computers.

Plasma panels

A plasma display consists of two glass plates separated by a thin gap filled with a gas such as neon. Each of these plates has several parallel electrodes running across it. The electrodes on the two plates are at right angles to each other. A voltage applied between the two electrodes one on each plate causes a small segment of gas at the two electrodes to glow. The glow of gas segments is maintained by a lower voltage that is continuously applied to all electrodes. A similar pulsing arrangement is used to selectively turn points off.

Electroluminescent panels

In an electroluminescent display (ELD), the image is created by applying electrical signals to the plates which makes the phosphor glow.

Volatile

Volatile displays require that pixels be periodically refreshed to retain their state, even for a static image. This refresh typically occurs many times a second. If this is not done, the pixels will gradually lose their coherent state, and the image will "fade" from the screen.

Examples of volatile flat panel displays

• Active-matrix liquid crystal display (AMLCD)
• Electronic paper: E Ink, Gyricon
• Electroluminescent display (ELD)
• Digital Light Processing (DLP)
• Field emission display (FED), also named nano-emissive display (NED)
• Interferometric modulator display (IMOD)
• Light-emitting diode display (LED)
• Liquid crystal display (LCD)
• Organic light-emitting diode (OLED)
• Plasma display panel (PDP)
• Quantum dot display (QLED)
• Surface-conduction electron-emitter display (SED, SED-tv)

Only a few of these displays are commercially available today, though OLED displays are beginning deployment only in small sizes, mainly in cellular telephones. SEDs were promised for release in 2006, while as of November 2005^[update], FED-NEDs were in the prototype stage.

Static

Static flat panel displays rely on materials whose color states are bistable. This means that the image they hold requires no energy to maintain, but instead requires energy to change. This results in a much more energy-efficient display, but with a tendency towards slow refresh rates which are undesirable in an interactive display.

Bistable flat panel displays are beginning deployment in limited applications (Cholesteric displays, manufactured by Magink, in outdoor advertising; electrophoretic displays in e-book products from Sony and iRex; anlabels).

See also

• Computer monitor
• Electronic paper
• Flexible display
• Large-screen television technology
• LED-backlit LCD television
• Mobile display
• On-vehicle display
• Sony Watchman
• Stereoscopy 3D displays requiring no special glasses
• Touch panel
• Transparent display

References

External links

• TFT Central, flat panel monitor reviews, news and articles
• Finetech Japan, FDP exhibition and conference
• Feature: Strange Inventions You Never Knew About

Wikimedia Commons has media related to: Plasma displays

Wikimedia Commons has media related to: LCD computer monitors

Wikimedia Commons has media related to: LCD TVs