Panasonic plasma TVs are known for their black levels. After gobbling up Pioneer the company has been incorporating Pioneer’s KURO technology to enhance black levels for its plasma offerings. And that’s one of the most important reasons why people buy Panasonic plasma TVs. But there is a problem: some users of Panasonic plasma TVs have experienced black levels that suddenly become not so black. There is a lot of chatter on AVSForum and this problem has been going on for some time, at least since July of 2009. It has taken a very long time but Panasonic is offering up some answers to this sudden change in black levels on its plasma TVs:
In order to achieve the optimal picture performance throughout the life of the set, Panasonic Viera plasma HDTVs incorporate an automatic control which adjusts an internal driving voltage at predetermined intervals of operational hours. As a result of this automatic voltage adjustment, background brightness will increase from its initial value … The newest Viera plasma HDTVs incorporate an improved automatic control which applies the voltage adjustments in smaller increments. This results in a more gradual change in the Black Level over time.
Panasonic needs to give the owner the option to turn this automatic brightness control off. via Engadget