The expanding market for microdisplays
12/01/2001
Maya Thornell, US Display Consortium, San Jose, California
Topping the list of characteristics in demand for electronic displays are portability, brightness, low power, high resolution, and wireless connectivity. To address these demands, the industry has increasingly focused R&D and production efforts on maximizing the capabilities of microdisplay technology.
Since the image size produced by a microdisplay does not depend on the physical size of the component, devices using the technology can provide high-resolution, big screen images in small, portable packages. Issues around system integration and the hunt for killer applications, however, have slowed the drive to market of equipment and devices with microdisplay systems.
Market and applications
Stanford Resources predicts that the "world market for microdisplays as components will grow from $669 million in 2001 to $1.9 billion in 2007, for a compound annual growth rate of 19%, with more than 44 million units shipped in 2007" (Microdisplays 2002). This technology currently dominates in two markets, presentation front projectors and camera/camcorder viewfinders.
In 2000, with InFocus leading the way, projector integrators sold more than 1 million front projection systems, resulting in factory revenue in excess of $4 billion, according to the McLaughlin Consulting Group ([MCG]; see figure). With the introduction of the next generation of extended graphics array (XGA) lightweight projectors, MCG expects the market to reach 4 million units by 2005, with street prices falling well below $2000.
 Microdisplay revenues, 1998-2005. Courtesy McLaughlin Consulting Group |
The goal for portable projector manufacturers is the production of maximum lumens with minimal weight. "Road warriors" are familiar with lightweight front projection display systems. These ultraportable projectors are most commonly used in making business and educational presentations to small groups, and weigh under 6 lbs. Portable projectors in the 6-11 lb range typically project an image at 800-1000 lumens. Epson recently introduced a 15-lb portable that projects 3000 lumens, the PowerLite 7700p.
A comparable version put out by Sanyo, the PLC-XP30, weighing slightly more than Epson's PowerLite at 19.9 pounds, also provides 3000 lumens. The future for projection includes potentially huge markets in home entertainment systems, digital cinema, HDTV broadcasting, classroom use, and kiosks.
Viewfinders for camcorders and digital cameras are a mainstay for the microdisplay market, as they are currently the only high-volume application. Whereas a few years ago microdisplays were only found in a handful of high-end camcorders, today they are the primary display of choice in all digital camcorders and the majority of digital still cameras. Microdisplay viewfinder units, according to MCG, are forecast to grow from 5 million units this year to 20 million units by 2005, and to generate more then $300 million in microdisplay module revenues.
Microdisplay technology
Microdisplay chips are typically fabricated using existing semiconductor foundries, thus eliminating the need for investment in expensive fabs, but end-user devices are still expensive. The display industry attributes the high cost of microdisplay devices to an immature technology infrastructure and low production volumes. Except in the case of viewfinders, microdisplay devices have not reached volumes that spur market competition and drive down prices. Developers are on the hunt for the magical mix of attributes, application, and price that will win over consumers and help drive industry growth.
There are a variety of technology options competing in the microdisplay market, each with advantages and disadvantages. A challenge for developers is to match the right technology with the right application. Several technologies have managed to carve out a niche.
High-temperature polysilicon (HTPS) liquid crystal displays (LCDs) are transmissive panels containing a high density of pixels. Fabricated with quartz wafers, HTPS panels use a liquid crystal layer to modulate light and create an image. HTPS technology can package XGA resolution into a 0.9- or 1.3-in. diagonal panel. The major suppliers of HTPS panels are Sony and Epson. Sarif is a fairly new supplier of HTPS panels for use in projection systems. Although LCD displays hold the market lead, that lead is expected to shift significantly with the growth of microelectromechanical systems (MEMS) and liquid crystal on silicon (LCOS) chip technology.
Texas Instruments (TI) pioneered MEMS-based technology for its Digital Mirror Device (DMD). The DMD system uses an array of extremely small mirrors on a silicon chip to control the projection of light from a light bulb onto a screen to create a moving image. When a DMD device is implemented into a projection system, it is referred to as a Digital Light Processing (DLP) system. Early versions of DLP technology had problems with color breakup, but these have been solved with faster frame rates. TI is said to be working on next-generation process technology that will decrease feature sizes from today's 14µm pixel to a 12µm pixel by 2002.
TI supplies DLP subsystems to more than 30 of the world's projector manufacturers. It sold $350 million worth of DLP products in the business projector markets in 2000. With its high contrast, brightness, and quick response time, DLP technology may soon compete with CRT projection systems for the home entertainment projection market. Hitachi, Mitsubishi, and Panasonic produce large-screen rear projection TVs that use DLP technology.
LCOS is another quickly emerging microdisplay technology. LCOS displays contain a thin liquid crystal film sandwiched between a silicon CMOS chip and a glass plate. The silicon chip serves as the reflective layer and contains the pixel-switching electronics. LCOS devices are expected to become successful in personal electronics using virtual display systems and projection products.
Unlike HTPS, LCOS technology offers a higher-resolution display and is smaller, ranging in size from 0.35-0.5 in. Stanford Resources projects that by 2007, LCOS microdisplays will account for 40% of the combined value of the camcorder and camera viewfinder markets, as well as 41% of the emerging near-eye market, now in relative infancy.
In what seems to be a trend toward LCOS technology by chipmakers, United Microelectronics Corp. (UMC), Taiwan's second largest chipmaker, is ramping up its current capacity of 2000 wafers/month, to 12,000 wafers/month by 2H02. UMC's LCOS process is an enhancement of its generic, mixed-mode CMOS process. Arizona microdisplay maker Three-Five Systems is using UMC's LCOS backplane-manufacturing process to develop its microdisplays. UMC also sponsors a Taiwan LCOS Microdisplay Consortium that works with companies like Three-Five,
Acer, Unipac, and Prokia. The goals of the consortium are to support its members in developing LCOS technology and to establish technical standards.
Fujitsu Microelectronics America has also developed application-specific processes for LCOS microdisplays, including 0.35µm LCOS for microdisplays, a 0.35µm CMOS image sensor, and 0.65µm and 0.50µm high-voltage processes. Fujitsu's 0.11µm CMOS process technology will be ready for use in production wafers by 2002.
Displaytech, Zight, Kopin, and Three-Five Systems are leading suppliers of LCOS displays primarily supplied for viewfinders and projection systems. In a collaborative effort with Corning and ColorLink, Three-Five uses its LCOS microdisplay imager in Thomson Multimedia's LCOS HDTV for RCA.
Displaytech has shipped 700,000 LCOS products in 2001 alone, a record for shipments of its core technology ferroelectric LDCs. Philips Components, a recent entrant in the LCOS market, introduced its engaze LCOS technology this year, the first single-panel LCOS display boasting a very high resolution image that contains close to one million pixels.
Emerging applications
Microdisplays will next penetrate the market for big screen TV sets. A number of companies including TI, Sony, and Epson are developing projection systems to compete with CRT-based projectors. HTPS and DLP technology will be major competitors in high-definition TVs, but LCOS is also being introduced into the market. The majority of these products are still on the high end compared to the price tag of rear-projection CRT units: For example, you can find a 50-in. CRT rear-projection TV for under $2000; the new RCA 50-in. HDTV using LCOS technology is expected to retail for around $7000.
Projections are that the overall prices for these products will dip to $3000 by 2002, however, making room for more competitors to enter and expand the market.
Near-to-eye devices like headsets and near-eye displays are touted as the next generation of display devices, but, according to an MCG study, technical problems in terms of pixel count, resolution, and contrast create barriers to their success. Industry leaders are in agreement that total acceptance of headsets and near-eye displays by consumers will depend on comfort, ergonomics, price, and styling of the devices.
Infrastructure, power, and price constraints are also contributing to the delay of bringing devices like portable DVD headsets, home-gaming applications, and wearable computers to market. When prices for the production of high-resolution displays and components come down, manufacturers will be able to make products at prices that are attractive to consumers. Major players in the industry agree that the movement from demos to volume will occur several years from now when products and manufacturing processes have had an opportunity to mature.
The display industry believes, however, that microdisplay devices, viewed in their entirety,will enable the third generation of wireless devices, and bring to market electronic devices that are sleek and energy efficient. The potential for large, high-resolution, rich content images from a tiny display seems infinite. Microdisplay technology can ultimately change the way the world will view information and entertainment, from the low-power, system-on-a-chip near-eye microdisplays, to large flat TVs powered by projection systems. Meanwhile, the microdisplay market will maintain itself with viewfinders, small projection systems, and the expanding big screen TV markets.
Acknowledgments
Digital Mirror Device and Digital Light Processing are trademarks of Texas Instruments. engaze is a trademark of Philips Components.
Maya Thornell is marketing/communications manager at the US Display Consortium (USDC), 60 South Market St., Ste. 480, San Jose, CA 95113; ph 408/277-2400, e-mail [email protected], www.usdc.org.
This article is based on information gathered for USDC's industry newsletter DisplayTrends.