New LEDs Offer Vision of the Future
We’ve heard it all before: Headsets with tiny display screens that will allow us freedom of movement while viewing high-resolution images.
But most of the headsets we’ve seen in the marketplace are awkward to wear, provide disappointing images and eat batteries for breakfast.
That’s about to change, according to major players in the imaging field. A relatively new technology, organic light-emitting diodes, has moved from the research lab to the manufacturing industry, promising to replace everything from liquid-crystal displays on cell phones and laptops to the 20-inch monitors sitting on many computer desks.
“This is absolutely going to explode” across the consumer marketplace, said John Burtis, research associate at Eastman Kodak Co. in Rochester, N.Y.
Kodak has licensed its technology to several companies, including Sanyo Electric Co., which is expected to introduce a small monitor next spring, and Pioneer Electronics, which is already producing car radios with display screens based on organic (carbon-based) light-emitting diodes.
Diodes have several major advantages over liquid crystals in that they emit their own light so they don’t have to be backlighted, thus reducing energy requirements substantially, and they can be viewed from any angle, even in bright sunlight. According to researchers, they can produce images that rival the best television sets, and yet are entirely portable.
Two very different fabrication technologies are competing for center stage in this arena. Cambridge Display Technology of Cambridge, England, a spinoff from Cambridge University, has come up with what it calls a very inexpensive method for producing diodes. It prints them on a thin film using inkjet technology, plastering the film with tiny diodes in much the same way that a desktop printer splatters droplets of ink on a sheet of paper.
That technology was developed with the aid of U.S. researchers at USC and Princeton University.
Kodak’s technology uses a tried-and-proven method familiar to the manufacturing industry--vacuum chamber deposition. The organic material used for the diodes is heated until it turns into gas, which passes through the vacuum chamber and deposits uniformly on a substrate of either glass or film.
Proponents of the competing technologies claim different advantages. Inkjet printing is cheaper, according to the British researchers, but the vacuum chamber produces much smaller diodes, or pixels, and thus higher resolution, according to Kodak.
There probably will be a market for both.
One of Kodak’s partners, EMagin Corp., will produce organic light-emitting diodes that are deposited directly on silicon chips, expanding the technology to very compact devices, including headsets, with extremely high resolution, according to Gary Jones, chief executive of the company. EMagin is also affiliated with IBM Corp. and is based on IBM’s campus in East Fishkill, N.Y.
“By putting it on the chip, we are able to build the entire electronics structure for the display system in a single chip,” Jones said. The viewing screen is incredibly small, about the size of a fingernail, he said, but it won’t look that way to the user.
Placed in a headset and positioned close to the eyes, the system plays a little optical trickery. The user has the sensation of looking at a much larger screen, “like a 19-inch monitor, or the best seat in a movie theater,” Jones said.
“You have no concept that there is a small screen that’s magnified,” he added.
EMagin expects to provide the chips to several manufacturers, but nothing is available yet to consumers. The 8-year-old company has concentrated mostly on fulfilling contracts with the U.S. Defense Department and other governmental agencies, including NASA. The company recently unveiled a display system developed for the military that features more than a million pixels, or points of light, on an area smaller than a postage stamp.
Jones expects the first commercial application to be in headsets and viewing ports for digital cameras. Instead of the dinky screens seen in today’s generation of cameras, the port will be even smaller but will appear to be the size of an 8-by-10 photograph with resolution high enough to let the user see exactly what the camera is going to get.
The technology also lends itself to laptops.
“You can carry around something that folds up and fits in a pocket,” he said. “You can have a full-size desktop screen experience, but with something that weighs a sixth of a typical laptop system today.”
Kodak’s Burtis said the beauty of the new technology is that it meshes so well with current manufacturing techniques for liquid-crystal displays. Most of the process remains unchanged, with a vacuum chamber substituted for “filling the liquid-crystal device with the liquid materials,” he said.
“The electronics, the testing, the integration is pretty much identical to what they are doing today with liquid crystals,” Burtis said.
Burtis believes light-emitting diodes will also replace the monitors we use today. The limiting factor in terms of scale is the size of the vacuum chamber used by the manufacturer. So far, those are pretty small, producing screens up to 5.5 inches on the diagonal, but Sanyo is building a system that should yield a 10.4-inch screen by next spring, and possibly a 15-inch device in 2002 and a 20-inch device in 2003, Burtis said.
And they will be incredibly thin.
The devices fabricated so far at Kodak are only eight-hundredths of an inch thick, he said.
So if the players in this high-stakes game are right, you soon will be able to kiss your liquid-crystal display goodbye. It served us well, but its days seem to be numbered.
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Lee Dye can be reached via e-mail at leedye@gci.net.
