DISPLAY TECHNOLOGIES IN JAPAN

June 1992

Lawrence E. Tannas, Jr., Tannas Electronics (Panel Cochair)

William E. Glenn, Florida Atlantic University (Panel Cochair)

Thomas Credelle, Apple Computer

J. William Doane, Kent State University

Arthur H. Firester, David Sarnoff Research Center

Malcom Thompson, Xerox Corporation

BACKGROUND

The Japanese have recognized that as we enter the Information Age, both the computer industry and the television industry will need new display technology. The introduction of the laptop computer has created a need for a thin panel display with good readability and low power consumption. Television is entering a new era of high definition television (HDTV). The Japanese have recognized that new display technologies are critical to making their electronic products highly competitive in the world market.

SUMMARY

Japanese-U.S. Comparison

The panel feels that U.S. display technology is competitive in some areas and superior in others. However, without the long-term investment in manufacturing facilities and the resolve to lower manufacturing costs by addressing both the computer and consumer markets, the U.S. will not be able to profit from its investment in display research. Japan is currently expanding its lead in product development, is dominating in investment and manufacturing implementation, and is competitive in basic research (and gaining). The relative status of the U.S. and Japan in flat panel displays is shown in Table 14.

TABLE 14
Comparison of U.S. and Japan in Display Technologies

(see Key)
[table 14]

Liquid Crystal Displays

By the mid-1980s, it was becoming obvious to displays industry experts that the Japanese displays industry was beginning to make significant breakthroughs in technical developments and in the manufacturing of liquid crystal displays (LCDs). In Japan, the stage is nearly complete for the production of flat panel displays (FPDs) through the end of the 1990s. The LC FPD industry is now orders of magnitude ahead of the other FPD technologies. The research, development, and production activities in Japan are so focused on LCD technology that funding for advancing electroluminescent (EL), plasma, and other FPD technologies is diminishing. In Japan, LCDs are perceived as clearly being the leading edge technology, but the cost and complexity of the new amorphous silicon (a-Si) LCD factory are so extensive that the larger machines of the next generation will not be attempted until the present generation of machines have completely proven themselves and been paid for.

Liquid Crystal Materials

Low-molecular weight nematic liquid crystalline materials for twisted nematic (TN), super-twisted nematic (STN), and ECB displays are well developed, and European nematics materials producers have established joint ventures in Japan to tailor-make mixtures for display manufacturers.

Most improvements in TN and STN displays are expected to come from materials such as retardation films and improved alignment layers. Japanese companies are the only suppliers of retardation films. Other improvements are expected to come from the synthesis and design of new low-molecular weight LC materials for ferroelectric chiral smectic (FLC) displays. Also, several Japanese companies are studying new molecular forms. Gray scale was perceived to be a major problem by most of the Japanese companies.

Most Japanese companies had research programs on polymer-dispersed liquid crystals (PDLC) materials, and there appeared to be interest in these materials for projection applications. Advances are also being made in the development of blue and white EL phosphors. In the plasma display panels (PDPs), new designs and success in discharge cell structure are expected to give new focus to materials research.

University researchers in Japan are more aware of display materials problems and industrial needs than are their counterparts in the United States and Europe. University research is more basic in general, and basic research on liquid crystals is more driven by display technology than in the U.S. and Europe.

Active Matrix Liquid Crystal Technology

Over the past few years, progress in active matrix LC (AMLC) technology has been spectacular. Remaining questions are how low the cost can be, how fast they will penetrate the market, and how good their ultimate performance will be.

Manufacturing issues have become the prime focus of research and development. Research is continuing on low-temperature polysilicon. The market niche that drives polysilicon currently is for view finders and projection light valves.

The main thrust in AMLC technology is directed towards developing cost-effective manufacturing of amorphous-silicon active matrix liquid crystal displays (AMLCDs). In these applications, the ability to integrate the drive electronics onto the AM substrate provides a significant, and at times enabling advantage. Seiko-Epson and Toshiba continue to develop metal-insulator-metal (MIM) technologies, but MIMs are expected to only serve limited applications in which cost is more severely constrained than performance.

There is intense competition for market share, because many major Japanese corporations view this area as a strategic long-term investment.

Passive Matrix Liquid Crystal Displays

Passive matrix LCDs dominate the flat-panel display business today, and will continue to dominate it, at least in unit sales, for the next five years. The passive matrix LCDs covered in this panel's report are twisted nematic, supertwisted nematic, vertically-aligned nematic (VAN), and ferroelectric.

Film-compensated STN (FSTN) LCDs have enabled a new industry (portable and notebook computers), and are also used widely in Japan in word processors. Color FSTN LCDs will continue to improve and will be introduced to the market in significant numbers in 1992-93. FSTN LCDs have not reached their full potential, and improvements are expected in several areas in the next few years.

VAN LCDs have made impressive gains but probably will be limited to niche markets because of their slow response time and low optical efficiency. Ferroelectric LCDs are under active development at a few laboratories, but only Canon has announced production plans. If Canon has solved the manufacturing problems, then these displays will give competition to active matrix LCDs, especially in the larger sizes.

Projection Displays

In Japan, much of the new display development has been motivated by the high-definition television market. At this time the only feasible options seem to be either direct-view large panels -- such as PDPs or AMLCD panels -- or projectors. In the short term, only projectors seem to have the cost and performance characteristics for consumer HDTV displays. For large screen displays, cathode-ray tube (CRT) projectors with good performance have been produced.

Currently, university laboratories in both the U.S. and Japan are doing competitive basic work. In both countries, a large part of the basic research is funded by governmental agencies. Although research in CRT projectors continues, the major effort seems to have shifted to AMLCD light-valve projectors. These projectors provide images with excellent quality and have a number of cost and performance advantages.

Efforts at this time seem to be concentrated on reducing cost and increasing the yield of projectors of the current design in an effort to have consumer-quality projectors available by 1995. The major thrust of the effort seemed to be to concentrate on products using current system designs.

Future Trends

Future display needs will probably be met with a combination of types. For small displays -- from 14- to 16-inch diagonals and eventually up to 20 inches -- it is expected that LCD panels will dominate for the foreseeable future. At present this market consists primarily of passive matrix LCDs, but higher performance AMLCD panels are rapidly expanding their share of the market. It is expected that CRTs will still dominate the market for 20- to 30-inches sizes. For displays larger than this, light-valve projectors using AMLCD panels are thought to be the near-term solution. In the longer term, NHK and several others expect plasma panels to be used for the long-sought-after "hang-on-the-wall" display.


Published: March 1994; WTEC Hyper-Librarian