New Plasma Displays Boast Higher Contrast Ratios

For home theater fans, plasma display panels (PDPs) are among the most promising technologies. The space-saving flat panels eliminate the need for projectors and screens or huge boxy rear projection sets, but their acceptance by critical viewers has been hampered by a low (400:1) contrast ratio which renders black as more like charcoal gray.

Panasonic is one company that has risen to the challenge. The company’s Los Angeles-based broadcast and television systems unit has unveiled a new plasma screen boasting high brightness, a high contrast ratio, and a wide viewing angle.

Designated as model TH-50PHD3U, the new unit debuted at the INFOCOMM 2000 trade show in mid-June. Scheduled to land at retailers this fall, the 50" diagonal high definition display features a 16:9 aspect ratio with UXGA resolution of 1366 x 768 pixels, a panel brightness of more than 500 cd/m2 and a contrast ratio of over 2000:1. It is said to offer "a palette of 16.77 million colors and 1,024 shades of gray," with a "horizontal/vertical viewing angle of more than 160 degrees, permitting unrestricted viewing even if the audience is not directly in front of the unit."

Plasma displays with even higher performance are coming soon from Pansonic's parent company Matsushita and others. In Japan, Matsushita has already rolled out 42" plasma displays with a new driver technology delivering a 3000:1 contrast ratio, comparable to the contrast of CRT monitors. Low contrast in early versions of plasma displays was caused by a phenomenon called "preliminary discharge" which keeps the pixels slightly aglow even in no-signal conditions. This has been corrected by a method the company calls "Real Black driving technology," originally developed by Plasmaco Inc. of Highland, NY, which Matsushita purchased in January 1995. A low contrast ratio was not considered a problem with early plasma units because they were intended primarily as commercial signage and information displays, but it has been the major obstacle in getting the units into home theater systems.

The industry is pushing hard to boost the quality and quantity of plasma displays. Matsushita plans to build a new fabrication facility for volume production, company officials recently announced—a $280 million volume-production line in Ibaraki City, Osaka, with a capacity of 30,000 units a month. Operation will begin in June 2001 with a startup capacity of 10,000 units/month. Matsushita and Plasmaco have built 50" and 60" prototypes. The new plant will produce 42" and 50" panels; Plasmaco will make the 60" models.

NEC Corporation says it is expanding production from a capacity of 5,000 units a month to 12,000 units by next March. Pioneer is boosting its PDP output from 50,000 to 150,000 units a year, and is building a second plant in Shizuoka, Japan, with a production date to begin in autumn of 2001. Sony has announced a 15% stake in Fujitsu Hitachi Plasma Display (FHP), the primary maker of the devices. Fujitsu projects that the market for PDP will grow to 500,000 units this year, 1.1 million units in 2001, 2 million in 2002 and 3 million in 2003. Fujitsu expects two-thirds of those panels to be for home use three years from now.

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