Date Visited: October 4, 1991
Report Author: T. Credelle
Stanley is basically a lighting company, founded in 1920 to develop automotive lighting. Besides normal incandescent lamps, they produce bright LEDs and are investigating discharge lamps. At their Tsukuba Research Center, they are looking at biotechnology. Today the main products are automotive lighting, displays, control panels, and biotechnology for light conversion. LCD sales are approximately 10 billion yen; total company sales are 200 billion yen.
LCD research began in the early 1970s; in 1984-85 Stanley began production of dashboard panels using direct-drive LCDs (guest host at first, then TN). They investigated STN but became intrigued by the homeotropic aligned nematic approach being developed by LETI in France. To develop the technology they applied for and received funding from Japan Research Development Corp. (JRDC), which lends interest-free money to companies for research. If the development is successful, then the money is repaid. JRDC has funded 2.3 billion yen in R&D, and Stanley has produced very nice-looking CSH-LCD (color super homeotropic LCD) in sizes up to 10 inches. The 10-inch panel was 640 x 480 pixels, 50 nits brightness, 15:1 contrast ratio, and 15 W power. Viewing angle is improved over STN, and gray scale performance is superior to STN. CSH advantages, according to Stanley are (a) easier gap control, (b) wider viewing angle, even in gray scale, and (c) potentially faster response time. The response time achieved to date is 250 ms (average of rise and fall); this is now inferior to color STN because of recent improvements. Main challenges for the technology are materials availability (LC manufacturers are focusing on TN and STN materials) and wide temperature range (especially for automotive). Today the resolution limits are determined by the multiplexing ratio (240:1 max). Stanley hopes to develop higher resolution if the basic VGA size is successful. Another serious limitation for portable PC use is transmission efficiency; the CSH transmission is 1.5-2.0%, about half that of color STN.
Part of the arrangement for the funding from JRDC is that a pilot production be established. Stanley is planning to do this but did not state the size of the line or the timing.
Stanley is doing only R&D in this field and did not discuss it.
Stanley has built a-Si TFT LCDs for potential use in automotive applications. All the major avionics manufacturers have approached Stanley, and they are working on some programs (confidential). They have demonstrated a 6-inch color TFT LCD in the past, but did not show it this year at the JES. They said that the requirements for automotive applications are very difficult; the biggest challenge is cost.
Stanley has developed RGB cold-cathode fluorescent lamps for LCD backlights. They are used by Stanley and others; outside sales are larger than inside sales. They now have 3.0- mm-diameter bulbs in production; Stanley feels that this is the minimum size practical for the near future.
EL backlights have also been developed for mono STN. Brightness is a problem, but 400 nits is perhaps achievable (STN transmission is typically 15%, so 400 nits translates to 60 nits). Efficiency of 4-5 Im/w is possible in either white or green. Biggest problem now is life; reports of 5000 hours at lower brightness (200 nits) have been made.
Stanley is researching thin-film EL and is focusing on organic materials at their Tsukuba Research Center. They have produced blue EL that "is visible in the lab" but said that life is a problem.
Stanley has produced metal halide lamps for automotive applications, but has not yet started working on projection lamps; it is not their main business. They indicated that they have some R&D in projection systems, but the level of effort was not stated.