LCDs (liquid crystal displays) could become cheaper, thinner, lighter and more flexible with a paint-on LCD-making technology being developed by researchers at Koninklijke Philips Electronics NV.
Researchers at the Amsterdam consumer-electronics company say they have devised a way to “paint” LCDs. A liquid crystal-polymer mix is applied to a surface, such as a sheet of plastic film, and exposed to two doses of ultraviolet radiation, to form first the walls and then a cover for each of the display’s pixels.
The process replaces the need to sandwich the liquid crystals between glass plates, which is what is done for current LCDs. Carefully connecting the glass pieces and filling the space with liquid crystals in a process called “vacuum suction,” is complex, time consuming and expensive, Philips said.
With the new technique, called “photo-enforced stratification,” the complete display is built from the bottom up on a single substrate by coating all functional layers on top of one other, Philips said.
The research team, led by Dirk Broer of Philips Research, has painted a passive-matrix black-and-white display measuring 100 millimeters by 100 millimeters onto a piece of glass. The next task for the team is to paint larger and better-quality displays on various surfaces, said Koen Joosse, a spokesman for Philips Research in Eindhoven, the Netherlands.
“Right now you can’t compare this with what you have on a notebook PC, but this technology is suitable for high-quality LCDs. The next steps are scaling up to larger displays and showing it on different substrates, such as plastic or fabric. We also want to go to active matrix and colour,” he said.
Support for flexible substrates could revolutionize LCD manufacturing, now tied to the rigid glass plates. Displays on plastic foil could be manufactured in a reel-to-reel process where large sheets run continuously through the manufacturing process. This is the ultimate low-cost, large-area manufacturing solution, according to Philips.
Philips envisions displays made using its technology in phones, on clothes and even on flower vases. However, it will be years before the paint-on LCDs come out of the research labs, said Joosse.
“This technology will be in a research stage for a while,” he said, adding that existing LCD manufacturing plants aren’t equipped to manufacture using this new process.
Philips isn’t the only one working on alternative ways to make LCDs. IBM Corp. of Armonk, N.Y., is active in the field, and Seiko Instruments Inc. last year used a curved display based on a flexible plastic substrate in a watch. However, Philips claims to be the only one that can make the ultra-thin paint-on displays.
