HDTV widescreen - Grey bars on side, not black?

Someone sent me this info:

http://www.highdefinitionblog.com/?page_id=6
Why Gray Bars and Sometime Black Bars?
Plain and simple the gray bars are used by the TV manufacturers to reduce the phosphor aging difference between the SD picture and the pillar box areas of the screen. If the pillar box areas of the screen were left black, the phosphors would not age as fast in those areas as the picture area would. Using the gray pillar box areas will cause the phosphors to age roughly the same as the picture area.

So why sometimes are there black bars? The black bars are added by the broadcasters for the 16:9 sub-channels. Once a sub-channel is formatted for 16:9 HD material, they will not switch the format. They just merge the 4:3 SD video into the black 16:9 frame. They could switch formats between the SD format of 480p and the HD format of 720p or 1080i, but that will cause most TV to blink and stutter while they resync to the new format, so they don't switch formats back and forth. So why don't the broadcasters use gray pillar boxes, you ask. Because black is the natural no video state and to use gray pillar boxes would require a video generator and quite frankly, they are not worried about your phosphor aging. Some broadcasters, like ESPN and our local FOX station, have added video generators to put their logo in place of the black bars.

Hey Ed,

I'm thinking that it's my cable box now. I have a Scientific Atlanta HD 8300 cablebox/recorder from Time/Warner. The 4:3 programs that are on the HD channels have black bars. On the regular channels the bars are grey. (btw, the TV is a Sony Bravia KDL-23S2010.)

The cable company tech support people don't know how to change this. I'll try again when I have more patience (and stop sobbing!) and ask for a higher level of support.

Why Gray Bars and Sometime Black Bars?
Plain and simple the gray bars are used by the TV manufacturers to reduce the phosphor aging difference between the SD picture and the pillar box areas of the screen. If the pillar box areas of the screen were left black, the phosphors would not age as fast in those areas as the picture area would. Using the gray pillar box areas will cause the phosphors to age roughly the same as the picture area.

Well that's a whole lot more technical (and longer-winded) than

gray is better because there actually is a signal and therefore less chance of burn-in.

Not to toot my own horn, but I am reminded of Mark Twain's famous line on brevity as a (time consuming) virtue- It goes something like this "Sorry this letter is so lengthy, but I didn't have time to write a shorter one". Maybe sometimes knowing the concept w/o the details is an advantage ;~)

Swampwalker why would you be tooting your own horn? What did you say that wasn't said above?

Kublakhan, I have one of those Sony LCD TV's and the bars are always black. I dont have a cable box. Just direct cable into the TV, over the air HDTV and a DVD player connected. The bars are always black no matter which 3 of these sources I watch. I guess its your cable box. I hope that helps.