updated 11:15 pm EST, Tue March 2, 2010
Customers claim degrading contrast ratio
Panasonic has been hit with a class-action lawsuit filed in a federal court in New Jersey. The plaintiffs allege that their plasma televisions no longer produce the same image quality as the company promised, as the brightness of black levels has slowly increased over time.
Although Panasonic has declined to comment on the situation, due to the pending lawsuit, the company last month responded to questions from CNET. The black level changes were acknowledged, although the change is said to be "automatic" over the life of the TV. The increase in background brightness was claimed to be necessary to "achieve the optimal picture performance throughout the life of the set."
The automatic voltage adjustment allegedly increases the black levels for several years until the "internal material characteristics" stabilize. "The Black Level at this stabilized point will yield excellent picture performance," the previous statement read.
Panasonic claims the lawsuit is baseless, however the company has yet to clarify its earlier comments or provide additional details. The newer Viera sets are claimed to integrate an improved automatic control which results in a more gradual change to the black levels.