Organic electroluminescent (EL) displays, which many regard as a next-generation display capable of replacing LCDs (liquid crystal displays), made appearances in several mobile device prototypes at the CEATEC Japan 2001 exhibition and wowed attendees with their bright, rich colors.
Sanyo Electric Co. Ltd., one of the leading developers of the technology, unveiled a prototype portable television with a 5.5-inch organic EL display and a two-hour battery life. The prototype display has a wide viewing angle, high brightness and high resolution with a fast response to moving images. The company hopes to make it as a product in 2003 in Japan and worldwide, said Mitsuhiro Ida, a spokesman for Sanyo.
The company is keen to use organic EL displays because they consume 50 percent less power than conventional LCDs with a back light. This power saving is made possible because the organic layer in the display glows itself and no battery-draining backlight is needed. Not only does this lower power consumption, and therefore increase battery life, on portable products, but it also means the displays are thinner and lighter, making them ideally suited to mobile devices, Ida said.
Organic EL display technologies are ready in the sizes used in cellular phones, he said, but are still too expensive for use in televisions.
Sanyo is also exhibiting 2.2-inch, 260,000-color organic EL displays for cell phones. These are intended for use in 3G (third-generation) multimedia phones, and will be on the market next year, the company said.
Sony Corp. attracted a massive crowd with a prototype 13-inch, 800 x 600 pixel, SVGA and 10-inch, 864 x 480 pixel, WVGA EL displays, each just 1.4 millimeters thick. The company hopes to commercialize them in 2003.
The picture quality of the displays is so high that even engineers from Pioneer Corp, another organic EL display developer, were praising them at Sony's booth.
Tohoku Pioneer Corp., its affiliate, made an early start on organic EL display development, beginning mass production of passive matrix organic EL displays in 1997. Its displays were used by Motorola Inc. in cell phones for the U.S. market last year. Unlike the active-matrix displays Sanyo and Sony are developing, the passive type does not include ICs (integrated circuits) on its base layer. It also doesn't require a glass base to carry circuits like the active type does, so that the display can be built on plastics.
In other words, although it carries only four colors so far, its structure is simpler and its manufacturing cost lower than the active type, according to Katsuhiro Kaneuchi, an engineer from the organic EL business operation unit of Tohoku Pioneer.
Pioneer's booth exhibited a prototype wearable plastic organic EL display attached to a winter coat. Tohoku Pioneer plans to keep developing both the passive and the active types simultaneously, and for products that don't need full colors, such as car stereos, it will adopt the passive type, Kaneuchi said. The company plans to start mass production of 1.8-inch and 3-inch active displays for cell phones and PDAs (personal digital assistants) in the fourth quarter next year, Kaneuchi said.
Other companies developing passive organic EL displays include Taiwan's Ritek Corp., which set up a company dedicated to the products last year. It will open a new plant manufacturing the displays on Nov. 15. Samples have already been tested, and the company hopes to ship the products commercially by the end of this year. Its target markets include PDAs in the U.S. and cell phones in Europe, according to Stone Shih, a Ritek spokesman.