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ELDis will exclusively supply Tohoku Pioneer, which will use the products in mobile phones and other devices equipped with OLED displays. Production will start in the fall of 2002 with initial output set at the equivalent of 500,000 (probably color) 2-inch panels, according to the companies.
Tohoku Pioneer currently manufactures passive-matrix OLED displays for use in cars and cell phones. Its parent company, Pioneer, was in 1999 the first to use the technology for a car-audio display. A prominent customer, Motorola, recently became the first to use it in a cell phone, the Timeport P8767, which was introduced in September. Motorola is suspected of awarding Tohoku Pioneer with a substantial new order last December, which may well have helped to seal the recent joint-venture agreement.
Tohoku Pioneer says it will double its output of OLED displays for mobile communication equipment such as cellular telephones this year. The company is also preparing a new production line with a capacity of 500,000 OLEDs per month, bringing total capacity to about 1 million displays per month.
Competition in the handheld market is also coming from Samsung NEC Mobile Display, a new joint venture between NEC and Samsung SDI. The primary target for the OLED displays will be 3G cellular handsets, where the venture hopes to garner a 30 percent market share by 2005.
Samsung, which has already licensed the small-molecule OLED technology from Kodak, will maintain a 51 percent stake in the company. The two may invest up to $450 million in the venture over the next five years. Production of cell-phone displays will begin in June 2001, with 2.2-inch passive-matrix OLEDs (128-by-128-pixel resolution) rolling out at a rate of 500,000 to 700,000 units a month. Capacity is expected to increase to 1.5 million units a month by 2003. Active-matrix OLEDs appear on the company's short-term development list as well.
In the hunt
Japan's Sanyo has also been an active developer of small-molecule OLED technology. In 2000, the company showed a full-color 5.5-inch panel. By the time this article appears, Sanyo should have completed an OLED pilot-line production facility, which should begin to make color active-matrix panels in 2002.
Taiwanese companies, whose investments in LCD technology in recent years are propelling them into a leadership position, are also showing interest in OLEDs. For example, Kodak licensee Ritek is already building 1- to 2-inch passive-matrix OLED displays (128-by-64-pixel resolution) on three production lines in Taiwan, turning out 24,000 units a month. The company has financial backing from Intel and Viewsonic. Picvue Electronics and Teco Laser Technology have also been developing small-molecule OLED products.
Elsewhere in Asia, Hoi Sing Kwok, a professor at the Hong Kong University of Science and Technology (HKUST), says his group has developed a new active-matrix OLED device. The active matrix is composed using low-temperature polysilicon technology, and the OLED layer is fabricated from small-molecule technology developed by Kodak. The significance of the low-temperature process, which Kwok is far from alone in pursuing, is that it allows the use of larger glass substrates. While still in the research phase, Kwok expects to see rapid commercialization of the technology.
Big picture show
Recently, Sony startled OLED developers by unveiling the largest OLED display to date—a 13-inch, full-color panel with 800-by-600-pixel resolution (SVGA). Sony intends to commercialize the display in 2003 for use in home-electronics products like televisions and computer monitors.
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OLED displays are simpler to make than LCDs, meaning they will be less costly. |
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One of the innovations in the panel is a new driving circuit, which has addressed a problem that has plagued larger-sized panels thus far: non-uniform luminance. OLED displays require a high degree of uniformity in the active-matrix transistors that drive each pixel. While producing highly uniform panels is possible, the yields so far have been too low to be commercially viable.
What Sony's Core Technology & Network Company did was alter the normal two-transistor structure, instead using four transistors per pixel. This technique results in uniform luminance and higher manufacturing yield.
The prototype sports brightness of 300 candelas/meter2 (a candela equals the light from one wax candle) and a 500-to-1 contrast ratio—quite adequate for its intended usage. However, display lifetime and emission efficiency apparently still need some work. Sony says its targets are 10,000 hours and 2 lumens/watt (lumens measure the rate of light emission; a typical candle generates 13 lumens).
Ready to roll
Production of polymer-based OLEDs has lagged behind the small-molecule versions, but that may be changing soon, says Stewart Hough, CDT's vice president of business development. "We expect some significant announcements in the next few months regarding polymer OLED production," Hough says. CDT recently changed its strategy and will now go beyond simple licensing. First up will be a manufacturing facility for its light-emitting polymers at its Cambridge headquarters. The company began ordering equipment in January and plans to start production in early 2002.
"We expect CDT licensees Philips Electronics, Delta Electronics and Osram to all start production of polymer OLEDS in 2001, probably by this summer," Hough says. A fourth licensee, Seiko-Epson, should begin production in 2002.
Here in the US, Uniax, which was recently acquired by Dupont Displays, has resolved a patent dispute with CDT and is installing a new production facility that should be online by Q4. The plant will initially produce monochrome, passive-matrix, polymer-based panels, but color active-matrix panels should be possible by 2003.
The company is still working on manufacturing issues, which need to be solved before customers will willingly commit to production. Uniax is working with four to five target customers in the Internet-appliance and wireless-product spaces to define the display-panel requirements and performance levels. "Each customer has a different set of requirements in terms of cost, power consumption, brightness, pixel pitch, and supply voltage," says Nicolas Colaneri, Uniax's business manager. "These have to be traded-off to define the customer's display."
Colaneri expects the company's first display products to be in the range of 1.5 to 5 inches, with pixel pitches of 300 microns and brightness of 150 to 200 candelas/meter2. For color OLEDs, the company still needs to develop materials that can emit saturated colors and to solve power-consumption problems, which worsen as the number of pixels increases.
Another US-based OLED developer, Universal Display Corp (UDC) has been busy lately too. UDC plans to begin pilot production of 2-inch OLED displays in 2001. The company recently expanded its intellectual property holdings by acquiring the right to license more than 75 OLED patents and patent applications from Motorola. These patents cover technologies relevant to most aspects of OLED manufacturing, including single-layer devices, packaging, plastic substrates, materials development, and encapsulation methods. UDC has been actively raising capital, striking deals, and winning contracts. To bolster its production supply chain, UDC struck an alliance with PPG Industries to help develop and supply proprietary chemicals for the OLED displays.
Micro action
Active-matrix OLED technology will also play a role in microdisplays. eMagin, for example, fabricates OLED small-molecule layers on top of a silicon substrate. These high-resolution microdisplays are then magnified for use in headsets that allow for private viewing of, for example, wearable computer displays or movies from portable DVD players. Production of these displays is expected in 2001 too.
Also helping to build the US infrastructure for OLED production is the US Display Consortium (USDC). This group has awarded a contract to Dow Corning to develop a high-temperature dielectric material for flat-panel displays. The material also has great potential as a moisture encapsulant for OLED displays.
From Canada comes another OLED developer, Luxell, which has developed a "black layer" technology for OLEDS. The company's technique helps to boost contrast, especially in high-brightness environments.
Blowing bubbles?
Taking a look at all the interest, activity and commitment to OLED technology currently underway, all we can say is "wow." This technology has truly caught fire. Let's hope that the level of enthusiasm is warranted—and not a bubble reminiscent of the recent dot-com bust. We will be watching to see if product commercialization rolls out according to plan over the next two years, and we'll let you know.
Author information
Chris Chinnock is the senior editor and publisher of Microdisplay Report, a monthly newsletter covering the technology and business of microdisplays and related products. He has been a technology journalist for the past nine years, before which he worked as an engineer and manager in several high-tech companies. This article is an expanded version of a piece that first appeared in Microdisplay Report.
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