Flexible Displays and E-paper: New Technology For Enhanced Cell Phone Applications

A Revolution Coming

The cell phone has become a ubiquitous accessory, seemingly for the majority of the humans on this planet. The features that cell phones now offer are blurring the line between phone and computer, especially when you are connected to the Internet. But there are two limitations that are hampering the cell phone from completely replacing the computer as the device of choice to surf the internet, and they are the display and keyboard—or, when considered together, the user interface.

Today we are restricted to viewing the World Wide Web on a cell phone through a 3" – 4” diagonal screen (or smaller) and inputting information on either a micro-keyboard or touch screen facsimile. Yes, one can surf the web and watch a movie with one of these devices, but it soon becomes tedious trying to cope with the tiny display. The piece of technology that is going to revolutionize the way people communicate, do business, surf the web, plan their days and coordinate their lives, is the flexible display. This is not to be confused with e-paper, or electronic paper, which is also a flexible display but uses a different technology that typically manipulates a material in the laminate to change its color or contrast to create an image. The current state-of-the-art for e-paper suffers from a slow response time and refresh rates, making it unusable for video applications but excellent for “static” applications like reading an electronic book or paper. E-paper is also much more energy efficient because it only uses power when the image changes and it uses reflected ambient light instead of a backlight as LCD’s use.

The Current State of the Technology

Flexible display technology is basically a sheet of plastic material that has the electronics embedded in it to display images. The wonder of this material is that it allows the display to be rolled up, or possibly folded. The technology is under hot and heavy development by many electronics companies and some universities including LG.Phillips, E Ink, HP, Fujitsu, GE, and the Flexible Display Center (FDC) at Arizona State University. This deceivingly simple technology will now allow you to have a cell phone—a personal computer/communication device, if you will—which will have a display that will open up to size that is much more practical to interface with the web. This may also be coupled with a flexible touch screen, which is also under development.

There have been several astounding demonstrations of flexible displays to date but they have yet to mature to the point of hitting the retail market. At

LG Phillips Flexible Color E-Paper Display Prototype

last year’s Consumer Electronics Show, LG.Phillips demonstrated a color, 14.3” (36.3 cm) flexible e-paper display with a resolution of 1280 by 800 and it was only 300 micrometers thick! (That’s roughly about 3 times thicker than the average human hair!) Sony demonstrated a 2.5-inch flexible OLED (Organic Light Emitting Diode – see OLED technology for more information) display that supports 16.8 million colors at a resolution of 120 x 160 pixels. Unfortunately, this technology is not ready for prime time.

What’s Taking So Long?

Anxious to get your hands on this technology?

Well, it’s not going to be available in a useful size for a while (that’s probably several years). You have to remember that the demonstration units you see in the videos are very special prototypes that are being shown under very carefully controlled conditions. It is a long way from these show pieces, running in an air-conditioned environment, to the displays you will be using in real world conditions from the beach to the ski slope. The display needs to roll and unroll reliably, time and time again so the plastic laminate has to remain flexible and transparent and equally important, the circuitry imbedded in it has to maintain its electrical integrity under these taxing environmental extremes. This is no small task for a device that is used and abused as much as a cell phone is.

If you consider that the current market estimates are predicting sales of over $6 billion by 2010 with the limited products available, to double that by 2015, you can be sure that the research and development efforts on flexible displays is only going to increase. So, it is not if you will have flexible displays on your cell phone, but when you will have them, and that time is coming very soon!