Source: “The Face of TV to Come: Plasma Vs. DLP,” by Phil Conner, Plasma TV Buying Guide
Quote: “Plasma, by contrast, uses a small electric pulse for each pixel to excite the rare natural gases argon, neon, and xenon (a k a “phosphors”) to produce the color information and light. As electrons excite the phosphors, oxygen atoms dissipate. These rare gases actually have a life and fade over time. Manufacturers of plasma have estimated the life of these phosphors to be about 60,000 hours. The life of the plasma display itself is usually determined by half-life of the phosphors. So at 30,000 hours the phosphors will be at their half-life, and the viewer will be seeing an image that has half the brightness capability that it did when originally purchased. This should be a good point at which to consider its life over. The gases in plasma TVs cannot be replaced. There is no phenomenon of “pumping” new gases into a plasma display.”
Yes, plasma panels are filled with inert gases such as argon, neon, and xenon, but these are not phosphors. When excited, these gases give off invisible ultraviolet light. Phosphors are chemicals that emit colored light when excited by ultraviolet light as in the case of plasma screens and fluorescent lights, or by electrons as in the case of a standard television picture tube.
And the gases do not age. That’s what “inert” is all about. The chemical phosphors do age, so that part is sort of right. But the manufacturers’ ratings are not to the end-of-life of the panel. Instead, the measure estimates how long it will be until the panel puts out half as much light as when it was new. (Note that this does not mean that the panel will only look half as bright, by the way.) So dividing the manufacturer’s rating in half makes no sense.
At least the part about not being able to replace the gases is correct. It would have been more helpful to point out that there is also no way to replace the phosphors, either.
(Many thanks to new HDTV Truth Patrol member Charles Laroop for submitting this item.)