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Flat TV Plasma

 

 

 

A plasma display (Plasma Display Panel - PDP) is a type of flat screen usually used for large TV. It consists of many tiny cells located between two panels of glass containing a mixture of noble gases (neon and xenon) with a phosphor coating. Each cell-pixel has three subpixels, one red, one green and one blue. When electric current flows through digitally controlled flat screen, the gas becomes electrically cells in plasma, which emits ultraviolet rays. Each of these lights makes the phosphor coatings to glow with the corresponding color.

 

 

 

 

 

 

 

 

 

The xenon and neon gases in a plasma TV are contained in hundreds of thousands of tiny cells between two crystal screens. The electrodes also are "confined" between both crystals, in the frontal and back part of the cells. The xenon, neon, and helium gas in a plasma television is contained in hundreds of thousands of tiny cells positioned between two plates of glass. Long electrodes are also put together between the glass plates, in front of and behind the cells. The address electrodes sit behind the cells, along the rear glass plate. The transparent display electrodes, which are surrounded by an insulating dielectric material and covered by a magnesium oxide protective layer, are mounted in front of the cell, along the front glass plate. Control circuitry charges the electrodes that cross paths at a cell, creating a voltage difference between front and back and causing the gas to ionize and form a plasma. As the gas ions rush to the electrodes and collide, photons are emitted.

 

 

 

 

 

Plasma display was invented in 1964 at the University of Illinois by Donald Bitzer, Gene Slottow and student Robert Willson for the PLATO computer system (Programmed Logic for Automated Teaching Operations: program logic for automated teaching). Were monochromatic (orange, green or yellow) and were very popular in the early seventies and for hardness needed because neither memory nor circuitry to refresh the image. In the late seventies there was a long period of declining sales due to the semiconductor memory made CRT displays for cheaper than plasma screens. However, its relatively large screen size and shallowness of their body made them suitable for placement in lobbies and stock exchanges.

In 1983, IBM introduced a 19-inch (48 cm) orange-on-black monochrome display. In 1992, Fujitsu created the first 15 inches screen (233mm) in black and white. In 1996, Matsushita Electrical Industries (Panasonic) purchased Plasmaco, its technology and its American factory. In 1997, Pioneer started selling the first plasma television to the public.

Screens size has grown since that screen with 15-inch 1992. The largest plasma screen in the world has been shown at the Consumer Electronics Show of 2008 in Las Vegas (USA) and is a 103-inch screen created by Panasonic.

During a long time it was believed that LCD technology was suitable only for small television and could not compete with plasma technology at larger screens (particularly 42 "and up).

Plasma displays are bright (1000 lux or more per module), have a wide range of colors and can be manufactured in large enough sizes, up to 262 inches diagonal. They have a very low luminance black level, creating a black level which is more desirable for watching movies. The lifetime of the latest generation of plasma displays is estimated at about 100,000 hours (or 30 years to 8 hours of use per day) for real time viewing, but there have been made TV plasma which reduced the consumption of energy and have lengthened the life of the TV. In particular, this is the estimated average life for the display, the time when the image has been degraded to half its original brightness. It can still be using it but it is considered the end of the functional life of device.

Contrast is the difference between the brighter and darker image, it is measured in discrete steps, at any given time. Generally, the higher the contrast ratio is more realistic image you get. Contrast ratios for plasma displays are often advertised 15,000:1 to 30,000:1. This is an important benefit of plasma over other display technologies but it is considered the end of the functional life of equipment.

It is often said that plasma screens have better black levels (and contrast ratios), although both plasma screens and LCDs have their own technological challenges. Some manufacturers have worked hard to reduce preload and the associated background glow to the point where black levels on modern plasmas are beginning to rival the CRT (cathode ray tubes). With LCD technology, black pixels are generated by a method of polarization of light and are unable to completely hide the underlying backlight.

A defect in the plasma technology is that if the screen is usually used to maximum brightness, it significantly reduces the lifetime of the device. For this reason, many consumers use a brightness setting below the maximum, but it is still brighter than CRTs.

In the phosphorus-based electronic displays (including cathode-ray televisions and plasma), the prolonged exposure to a static image can make that the objects displayed in it are marked on the screen for a while. This is due to the fact that fluorescent compounds that emit light lose their luminosity with use. As a result, when certain areas of the screen are used more frequently than others, over time low-light areas become visible to the naked eye, this is called screen burn. A common symptom is that the image quality gradually decreases according to the brightness variations that occur over time, resulting in an image that looks "muddy." If the screen stays on for a long time showing static images (like logos or news headlines) plasma screen has a greater tendency for the image is fixed or overwritten on the screen (although the new models since 2008 on brands like panasonic and Pioneer no longer have this burning).