Today, liquid crystal displays, or LCDs, are found in laptops, watches, and cell phonessandwiched between two rigid pieces of glass. But soon, LCD screens may be daubed onto walls or even clothing, say researchers at Royal Philips Electronics, who have devised a way of “painting” a computer screen onto a surface.
The new technique, discovered by five Philips researchers working at the company’s research laboratory in the Netherlands, could allow flexible, lightweight LCDs to be mounted on plastic sheets that can be rolled up or folded. The innovation could sustain LCD technology’s viability versus competing display techniques, such as organic light-emitting diode systems, said Bob O’Donnell, a display technology analyst with IDC Corp. If the technology catches on, cheap, paintable LCDs could wind up in unheard of places, O’Donnell said.
“Count how many screens you have in your home and multiply that by a big factor,” he said.
Cheaper LCD screens also might mean more teachers could use projection technologies in their classrooms. Because projectors are more expensive than computers, often several teachers must share a single projector, which means teachers can’t count on one being available when they need it, said Chris Mahoney, director of technology at Lake Hamilton Schools in Arkansas.
“One of the most important technology issues for our district is integrating technology into the classroom. The best way for a teacher to use technology resources is by means of projection,” Mahoney said. “Cheaper LCD screens would allow for more integration of technology into the curriculum, and more teachers would be able to use web sites, presentations with Microsoft PowerPoint, and graphical illustrations in their classrooms.”
The Philips technique, called “photo-enforced stratification,” involves painting a liquid crystal-polymer mix onto a surfacesuch as a sheet of plastic filmthen exposing it to two doses of ultraviolet radiation.
The radiation forces the mixture to separate into a honeycomb of tiny individual cells covered by flexible, see-through polymer. When connected to a computer, the crystal-filled cells change color to create a picture, like any LCD display.
Some kinks need to be worked out. So far, the company’s scientists have painted only glass with their liquid crystal-and-polymer mixture, because glass is less susceptible to the distorting contamination that plagues plastic.
An article on Philips’ research into the technique appears in the May 2 issue of the journal Nature. The article suggests that the LCD industry ought to quickly overcome remaining hurdles to the technology.
“We can look forward to the day when we will be able to put displays on almost anything,” the article says. The emergence of flexible displays is seen as one of the last impediments to more pervasive portable computing.
Wireless transmission, fast processors, and small memory components have allowed computers to shrink to fit inside portable devices, such as cell phones and personal digital assistants (PDAs). But screens have remained rigideither attached to a computer or shrunk to fit onto a cell phone or PDA, too small to surf the web in a rewarding way.
Several companies have marshaled developers to work toward lightweight, flexible screens that can be rolled up or folded and carried in a pocket.
Universal Display Corp., for example, based in Ewing, N. J., is working on what it terms FOLEDs, or flexible organic light-emitting devices, that could one day be laminated onto a school uniform sleeve, a school bus’s windshield, or the face guard of a football helmet.
A wireless, internet-connected display would allow someone to comfortably read, say, an instantly updated electronic textbook while riding on the bus.
Philips is exploring multiple paths toward this goal, developing flexible plastic transistors as well as a type of “electronic paper” display in concert with Cambridge, Mass.-based E-Ink Corp., which is developing paper-like screens. IBM Corp. also has done research on flexible displays.
“Trying to surf the net over your [PDA] is like watching a movie through a keyhole,” said Russ Wilcox, E-Ink’s co-founder. “What people want is a big display that is very portable, so they can get access to all the information on the internet.”
Philips is an investor and development partner for ultra-thin, lightweightbut non-flexibledisplays that E-Ink plans to release next year, Wilcox said.
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