What Does DC Restoration Mean With Regard to Plasma Display? (1 Viewer)

[Arthur S]

Cnet tested a Panasonic plasma and rated it poor in DC restoration. What does this mean? IIRC, it has something to do with black reproduction.

Can someone please elaborate?

Thanks

 

[Allan Jayne]

Poor DC restoration means that the voltage level that corresponds to black keeps drifting.

Should the error occur int he video waveform before the signal reaches the pixels, the usual result is what a pixel displays for black depends on what is to the left on that scan line and possibly what is on previous scan lines. Should the error occur in the display element(s) what the pixel displays for black may depend on what luminance the pixel had a moment before.

There are usually no problems with the video signal if the black level voltage is "resynchronized" at the beginning of each scan line namely making sure the back porch part of the waveform corresponds to zero volts.

The entire black to white gray scale could be shifted as a result of poor DC restoration and the result could be washed out highlights as well.

Video hints:
http://members.aol.com/ajaynejr/video.htm