SAN FRANCISCO (07/05/2000) - If you think flat-panel displays are the wave of the future, think again. Displays will be even smaller than that. Monitors may someday be available as thin plastic TV screens that you roll up, small electronic displays beneath every shelf item in a supermarket, and screens sewn into clothing.
These are just some of the futuristic uses of two new display technologies soon to enter the manufacturing stage. Called organic light-emitting diodes, or OLEDs, they use less power than today's LCDs, are thinner and weigh less, have wider viewing angles, and will probably be cheaper to make. They also can be flexible. And they're coming soon to personal digital assistants and phones.
OLEDs took a major step forward late last month when Seiko Epson Corp., the Japanese electronics company, and Cambridge Display Technology, (or CDT) a British company, demonstrated a prototype 2.5-square-inch color display that uses CDT's light-emitting polymer, or LEP, technology.
LEP displays could show up in cell phones and PDAs within a year, says Jeremy Burroughes, CDT's technical director. "We're working on everything from microdisplays to wall displays," he says.
DuPont Co., Philips Electronics NV, and Hewlett-Packard Co. are supporting CDT's technology.
In May, Eastman Kodak Co. announced a breakthrough in a rival technology called small-molecule OLED, which has different chemical properties from the polymer used in LEP. With its partner Sanyo Electronic Co. Ltd., Kodak unveiled a 5.5-inch color OLED, the largest so far. Other major Japanese companies, including Panasonic Consumer Electronics Co., Sony Corp., and Toshiba Corp., are backing it.
Double Vision
Polymers are chemical compounds whose molecules form structures that emit light when electricity is applied to them, eliminating the need for the backlight that accompanies many of today's LEDs. (LEPs function as backlights in certain kinds of LEDs, however.) The light is passed through red, green, or blue layers and separated to create the color pixels seen on screen. Though the initial products are made of glass, the polymers and related display layers can be plastic, opening up new possibilities such as the roll-up TV.
With LEP, the color pixels are printed with Seiko-Epson inkjet technology, which Burroughes says translates into 25 to 30 percent savings on that manufacturing step, reducing the display's final cost.
The two technologies are actually very similar. "It's almost exactly the same," says Barry Young, vice president at the DisplaySearch research firm. "So far, it's a small difference, as far as I can see."
The Kodak entry, however, is further along than LEP: Pioneer is already using the displays in some car stereos, and Motorola has introduced it in cell phones, Young says.
Most of the displays are only in prototype, he says, and sharper, active-matrix versions won't be widely available before 2002. Plastic screens are also at least two years away, according to Burroughes and Young.