Pioneer Corp is showcasing a PDP featuring a contrast ratio that is "too high to be measured" at 2008 International CES.
The company achieved the high ratio by eliminating the necessity of pre-discharge, which has been regarded indispensable thus far. The exhibited product is a 50-inch PDP introduced by the company Jan 6, a day before the opening of the Show.
The PDP was demonstrated in a separate room where the environment was made to be equivalent to that of a darkroom. The new PDP and an existing product were exhibited side by side so that visitors could see the effect obtained by the enhanced contrast ratio while comparing the two panels.
The demonstration clearly showed the difference. In the new panel, images were displayed as though they were floating in complete darkness, whereas black areas illuminated with light were clearly observed in the existing panel. The difference in the black level is especially apparent when each of the panels displayed entirely black.
The pre-discharge operation to apply an appropriate voltage on the electrodes in advance has been said to be necessary to drive a PDP in a stable manner at a high speed. If the electrode voltage decreases to absolutely zero without the pre-discharge, it takes a long time before the discharge even when the display voltage is applied. As a result, the PDP cannot be driven at a high speed, or at worst, the panel may fail to display images.
If the pre-discharge operation is performed, however, a slight amount of light may be sent to the screen so that black areas are illuminated undesirably. This prevents the panel from displaying true black.
Pioneer, which developed this PDP that doesn't need pre-discharge operations, has not revealed the details of the underlying technology. The company only reported that it entirely revised the previous technology and developed a new driving method. Without this proprietary driving technology, the latest PDP could not be developed, the company said.