16 December 2017

What is plasma display

History :

The plasma display was co-invented in 1964 at the University of Illinois at Urbana Champaign by Donald Bitzer, H.Gene Slottow and Robert Willson for the PLATO computer system. The original monochrome video display panel was very popular in the early 1970s because they were needed freighter memory nor circuitry to refresh the image. In the late 1970s, as semiconductor memory made CRT display cheaper than plasma displays. However, the relatively large screen size and thin body of plasma displays made them suitable for high profile placement in lobbies and stock exchanges. 

In 1983, IBM built in orange-on-black monochrome displayed. Today's display contains a grid of cells in which gas react with phosphors is varying degrees in red, green, or blue sub-pixels, making it possible to produce over 16 million different colors.

1992 - Fujitsu brought in the World's first 21-inch full-color display. 

1994 - Weber explains a color plasma display at an industry convention in San Jose. 
1995 - Fujitsu invented the first 42-inch plasma display. 
2006 - Analyst noted that LCDs overtook plasmas, particularly in 40-inch and above segment. 
2008 - The largest plasma video display in the world at the 2008 Consumer Electronics Show in Las Vegas, Nevada was manufactured by Matsushita Electric Industries. It was a 150 inches. 
2010 - Panasonic introduced their first 3D plasma model 152" 2160p. 

What is Plasma Display?

A plasma display is a computer video display in which each pixel on the screen is illuminated by a tiny bit of plasma or charged gas, somewhat like a tiny neon light. They are thinner than cathode ray tube ( CRT ) displays and brighter than LCD called Liquid Crystal Displays. 

Structure of Plasma display :  

A plasma display is made up of many thousands of gas-filled cell that are sandwiched in between (a) two glass plates, (b) two sets electrodes, (C) dielectric material, and  (d) protective layers.

The address of the electrode is arranged vertically between the rear glass plate and the protective layer. This structure is behind the cells in the rear of the display, with the contact layer in direct contact with the cells.

On the front side of the display, there are horizontal display electrodes that are in between a magnesium oxide (MgO) protective layer and an insulating dielectric layer. 

Electrodes in the horizontal and vertical direction form a grid from which each individual cell can be accessed. Each individual cell separated from surrounding cells so that activity in one cell does not affect another.

The cell structure is similar to a honeycomb structure expect with rectangular cells. To illuminating a particular cell, the electrodes that intersect at the cell are charged by control circuitry and electric current flows through the cell, simulating the gas atoms inside the cell. These ionized gas atoms or plasma's then release ultraviolet photons that interact with a phosphor material on the inside wall of the cell.

Every pixel on the display is made up of three sub-pixel cells. One sub-pixel cell is coated with red phosphor, another is coated with green phosphor, and the third cell is coated with blue color for the pixel. The control circuitry can manipulate the intensity of light which is emitted from each cell, and therefore can produce a large spectrum of colors. This light from each cell can be controlled and changed rapidly so that produce a high quality moving picture.

Advantages of plasma display :
  • Can be wall mounted
  • Simple profile 
  • High resolution 
  • Short response time
  • Better motion tracking 
Disadvantages of plasma display :
  • Poor reproduction of black
  • Brightness range is narrower 
  • Consume more electricity
  • Very costly
  • Heavier in weight 

For detailed information