By Chris Chinnock
MAKUHARI MEESE, Japan - Major Japanese developers of large-area, direct-view displays are demonstrating their latest prototypes in the 40-to-50-inch class. Although the makers intend these displays for televisions and computer monitors, such devices are expected to see increasing use in command, control, situational awareness, and image-analysis applications.
Most manufacturers are fielding a technology known as AC Plasma, which creates an addressable XY matrix of pixels composed of individual gas cells. A series of pulses ionizes the gas to create a plasma whose ultraviolet light then excites red, green, or blue phosphors.
At the Japan Electronics Show (JES) in early October, representatives of Fujitsu, Sony, NEC, Matsushita, Mitsubishi, Hitachi, and Pioneer showed either technology demonstrators or commercial products in large-area displays. Fujitsu engineers have been producing plasma displays for several years, while those at Hitachi, Pioneer, NEC, and Mitsubishi are set to begin production in early 1998.
Developing an alternative technology is a troika consisting of Sony, Philips, and Sharp. The three have licensed a technology from Tektronix of Beaverton, Ore., called Plasma Addressed Liquid Crystal (PALC). These large-area liquid crystal displays (LCDs) replace the thin-film-transistor active matrix with a gas plasma matrix. Consequently, the display looks and performs like an LCD, but uses a lower-cost switching method more suitable for larger pixels and bigger displays.
Most U.S. military, government, and intelligence users of large-area displays must use foreign-made displays because North American developers are not investing anywhere near the amount their Japanese counterparts are for development and manufacturing.
The recent Japan Electronics Show demonstrated Japan`s commitment to large-area, direct-view displays, says Roger Johnson, president of Wow Media in San Diego, a system integrator for plasma panels.
"Two years ago the emphasis at JES was on rear-projection TVs using LCDs. Since then, we have seen this technology move into homes and offices," Johnson says. "This year, I saw a huge emphasis on plasma and PALC technology for home theaters and offices. They have made a strong investment in manufacturing to serve this market and are backing it up with products."
Efforts to bring plasma and PALC displays to the commercial market is concentrated in two areas: wall-hanging TVs with 16-to-9 aspect ratios, and multimedia computer monitors with 4-to-3 aspect ratios.
At JES NEC officials unveiled a 50-inch plasma display of 1,365 by 768 pixels geared to Japanese television. Wide-screen television is broadcasting in Japan so a ready market for the 16-to-9 displays already exists. While the Japanese High-Vision system requires a 1,365 by 1,035 format, NEC engineers built their 50-inch display to scale this signal for viewing on their 768-line display. When packaged as a TV and placed on sale in Japan in January, it is expected to carry a price tag of around $22,000.
Pioneer officials also showed a 50-inch panel with 1,280 by 768 pixels suitable for quasi- High-Vision viewing. Aggressive pricing means Pioneer officials may offer TVs for less than $17,000 by early next year.
Even though these displays packaged as TV products may not be of direct interest to military or government users, success here will rapidly lower prices for displays in many other applications. Long held goals of $100 per diagonal inch could actually fall below this level as production from multiple sources increases over the next few years.
Fujitsu marketers used JES to unveil their improved 42-inch, 852-by-480-pixel plasma display. Called the model 4, it boosts contrast to 450-to-1 and increases brightness to 200 candela per square meter. "This performance is now on par with or even better than the highest performance CRTs," says Joe Virginia, director of the Flat Panel Display Business of Fujitsu Microelectronics Inc. of San Jose, Calif.
When packaged as a monitor, the device can accept either video (NTSC, PAL and SECAM) or data (VGA, SVGA and MAC) inputs, and present full-screen, 16-to-9-aspect-ratio images.
Johnson says he believes one of the main uses of displays of this size is in what he calls the small-office arrangement, which he defines as a four- or five-person meeting. Here, the applications will be video conferencing or presentations.
"CRT-based rear-projection TVs are too big and bulky, LCD front projectors are better suited for larger rooms and bigger audiences, and PC monitors are too small for convenient access and viewing," Johnson says. "Plasma displays are big, yet flat, and have a viewing angle of 160 degrees so you get much better visibility in fairly high ambient lighting conditions. Plus, you can switch from video to computer applications quite easily."
Hitachi and Mitsubishi officials believe there is something to this market, too. Hitachi leaders recently announced they would begin shipping the highest-density plasma monitor - a 25-inch, 4-to-3, XGA device - by the end of the year. Mitsubishi officials plan a 40-inch VGA model also by the end of the year.
Meanwhile, marketers from Philips, Sony, and Sharp each exhibited PALC displays that resulted from a cooperative development project that ended last July. Apparently, each will now further refine the technology and develop products to fit target application areas.
The 42-inch 16-to-9, 854-by-480-pixel displays from these manufacturers feature brightness of 400 candela per square meter, (what`s this) daylight contrast ratio of 100 to 1, and a symmetric 140-degree viewing cone. Although company officials have announced no production plans, Sony spokesman Mack Araki says sampling should begin by the middle of 1998.
Potential users should be careful in choosing displays for specific applications. With a wide variety of pixel formats and an even greater number of input formats - data and video-based - the interface electronics play a critical role. These electronics reformat images - stretch and/or compress incoming signals for presentation. Artifacts in the resultant image must be evaluated each application. This can be especially important for mission-critical military or intelligence applications.
The Plasmavision42 from Fujitsu Microelectronics Inc. is a color plasma display with resolution of 852 by 480 pixels and plug and play capability. It is among the large-area color displays developed in Japan.
