Friday, December 02, 2005

Displays Flex Some Muscle

Advances in materials could breathe new life into the market for flexible display screens.

By Eric Hellweg

It's been a big week for flexible displays -- the long-sought-after technology that could eventually lead to information devices that look and feel more like paper. On November 30, Seiko announced it had created a futuristic, curved digital watch, using technology introduced in the previous month by LG Philips and Cambridge, MA-based E Ink. Rather than the time displaying on a flat screen, the Seiko display is on the curvature of the bracelet.

Also this week, Samsung Electronics announced it has created a flexible, seven-inch color LCD screen -- the largest to date. The product is not yet available to consumers, and the company won't say when a prototype will be ready for market. But in an e-mail, Joe Virginia, a vice president with the company, said “this has been one of our major R&D projects and still is.”

Samsung’s announcement comes at a critical time for the display market. As companies such as Samsung and E Ink are making great strides, others are folding. For instance, according to a representative of Ann Arbor, MI-based Gyricon, a spin-off that wanted to commercialize electronic-paper technology originally developed at Xerox's Palo Alto Research Center, the company will be closing its doors on December 31.

The concept of a flexible computer screen has been a brass ring to engineers for at least a decade. I remember visiting an IBM booth at a trade show in 1995, for instance, where engineers were displaying developments in flexible screen technology. Yet basic problems, such as powering the screens and finding a material that bends yet works as well as glass, have kept it a small industry.

One reason, according to E Ink, is that manufacturing flexible screens requires temperatures higher than in typical manufacturing processes for display components. The screen that E Ink and Philips introduced last month uses a very thin stainless steel backing, which can withstand heat better than plastics and some other materials. Since E Ink’s display technology is reflective, rather than illuminated from behind like an LCD, its backing materials can be opaque.

Samsung’s screen is based on a thin-film transistor, liquid crystal display (TFT LCD), and relies on a transparent plastic substrate that the company claims is thinner, lighter, and more durable than standard glass-based LCD panels. Using a proprietary new method, they were able to overcome the heat sensitivity of plastic by significantly lowering the temperature in the manufacturing process. The screen supports resolutions up to 640 by 480 pixels.