The artifact presents itself as a yellowish trail behind moving edges on the screen. The reason is that the blue phosphor material stops emitting light much faster than the green and red phosphor material that can take several milliseconds to stop emitting light. Here is a chart plotting luminence versus time for all three phosphor materials on a 42" plasma display. You can see the PWM code as well as the trailing green and red luminence (combining to produce yellow trails). Note the quick rise time of the blue phosphor that contributes to blue leading edges.
Due to the time scale this artifact is very hard to detect for most people.
Originally Posted by XVN5
Hey guys, I'm one of those people who are highly affected by the plasma's uneven phosphor decay time. And it kills me the fact that I can never own due to this-one issue.
If you have any info regarding development of future PDPs without any uneven-phosphor decay problem, please let me know.
I would suspect the lack of research into fixing this issue may be driven by the lack of consumer complaint. The issue is a scientific fact but since the majority of consumers seem to not percieve the artifact there is little incentive to fix it. The unfortunate result is that consumers like you that find the artifact obvious, distracting, and essentially a turn-off to this technology are out of luck.
I've read only one patent (5 years old) on developing a fix to this problem and here is a snippet from it:In the future, the development of new chemical phosphor powders could avoid such problems by making the green and red phosphors quicker. Nevertheless, today it is not possible by signal processing only to completely suppress this effect but one can try to reduce it.
One known solution from the former patent application FR 0010922 of Thomson multimedia is to compensate the coloured trail while modifying the blue component in the temporal domain.
The most cumbersome on the phosphor lag effect is not the trail behind moving objects but its colour. Another solution is therefore to add a complementary trail on the color trail in order to discolor it or to add to the pixels in front of the moving object a complementary correction at least for the cells having the fastest response. These solutions are disclosed in another European Patent Application of the applicant EP 01250237.3.
These ideas applied together in a PDP give very good results, but need the implementation of a motion estimator.
The object of the present invention is to disclose a solution that compensates for the differences between the time responses of the three phosphors without the need of a motion estimator.