Rwwear"The gray bars are better for preventing burn-in but is really only important for plasma TVs."
Where did this information come from?Link?
Where did this information come from?Link?
HDTV widescreen - Grey bars on side, not black?
Well it is also true for CRTs but since we were discussing an LCD I didn't include CRTs. LCD TVs are not succeptable to burn in. They are but very slightly. I don't have a source. It is pretty common knowledge though. Okay here are some sources. http://www.lcdtvbuyingguide.com/lcdtv-plasmavslcd.shtml www.flattvpeople.com/tutorials/lcd-vs-plasma.asp www.audioholics.com/techtips/specsformats/displays_LCD_vs_Plasma3.html You'll have to read for yourselves to find the info. |
What model TV and how is it connected? Where the bars are introduced may depend upon how the signal is being transmitted from the source. For example, there is SD material occasionally transmitted on HD channels, where the black bars are "supplied" by the broadcaster. For some formats, I believe it may be generated by the CATV box. In other cases, it is generated by the TV... But, if you can't find a control for changing the bars on either your TV or the CATV box, sounds like it is pointless anyway... |
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. |