Plasma Display Panels

The invention of the plasma display was the breakthrough that produced large area flat panel displays. Because of the nature of the process used to create plasma panels, one can readily create large size arrays of light emitting elements. It didn't take long for the technology to move from monochrome to color and it has steadily progressed. Today you can find plasma panels that range in size from approximately 30" to 60” diagonally. Plasma Display Panels (PDPs) work by creating a plasma not unlike that which is in a fluorescent tube. The plasma generates ultra-violet light that strikes a phosphor and causes the phosphor to give off its characteristic color light (red, green, or blue). The luminant efficiency, while not extraordinarily high, is good enough to create a fine looking display. It is a technology that will survive in the area of 50" and larger - competing primarily against projection displays.

Plasma Display Panel Positive Characteristics:

• Can be made in large diagonal sizes
• Emits light so you can make a Lambertian wide viewing angle emitter
• Is as fast as a CRT with response time that can follow the fastest video motion
• The color gamut comes closer to NTSC color than even CRTs

Plasma Display Panel Negative Characteristics:

• Image burn-in - like every light emitter, the efficiency of emission for PDPs is diminished over time. So if you continually write the same image to one area, it eventually becomes "burned in". And, because the human eye can see fourteen orders of magnitude of brightness, it is possible to see the very subtle differences of the burn-in effect. This is an intrinsic property of all plasma panels that will be very difficult to surmount. Showing continuous video, is not as much of an issue as with graphics. But even for home theater or HDTV where you show a logo such as the CBS eye, it will not take very long to be burned in - typically 20,000 hours.
• Another problem with plasma displays is cooling. Because they are less efficient, you typically have to ventilate them well or cool them with a fan. This restricts the mounting for a plasma display. It can't be easily embedded into a wall or an enclosure unless provisions are made for cooling.
• The fast response time of plasma displays sometimes causes visible flicker that is visible to some viewers.
• Plasma displays do not have the dynamic contrast range to show highlights and features that are now possible with LCDs.