Flexible LCDs

By

This article was published by ComputorEdge, issue #2428, 2006-07-14, as a feature article, in both their print edition (on pages 20 and 22) and their website.

If you live in Silicon Valley or some other region that has a high density of computer programmers, you might find yourself standing in line behind someone wearing a T-shirt emblazoned with a sketch or a photo of a computer display.

But what if the shirt were stationary and yet the image was moving on the surface of the T-shirt? (This is assuming that you had not imbibed excessively.) What if the picture of a computer display could be an actual computer display, rotating through a set of screen saver images, or displaying a Web page in real-time?

Depending upon your comfort level with new technology, and whether or not you are a card-carrying member of Luddites International, you might be either thrilled or disturbed by a computer display built right into the fabric of some clothing. In either case, you may as well get used to the idea, because at some point in the not-too-distant future, the concept will move from the drawing board to the assembly line, and from there to the back of someone standing in front of you.

Roll Your Own Images

The idea that flexible LCD screens were technically viable, was first learned by the public when Toshiba announced in 2002 that it had created a large flexible liquid crystal display (LCD), measuring 8.4 inches diagonally. The display utilized low-temperature polysilicon, configured into an active-matrix thin-film transistor (TFT) that displayed full color, and with a resolution great enough to support Super VGA (SVGA), which is now the most commonly seen display standard.

No doubt anticipating that consumers would be far more interested in the potential applications than the science behind their invention, Toshiba proposed a number of potential applications for the curved screens, such as being used for information displays mounted in public areas. However, not anticipating all of the technical hurdles to be overcome, Toshiba also announced that mass production of commercial products would be launched by 2004. Two years later, we have yet to see widespread use of such products.

In 2002, Philips announced that they had developed a technique of painting a computer screen onto a surface, including plastic sheets that can be folded or rolled up, in a method known as "photo-enforced stratification". Video signals from a computer instruct the individual crystal-filled cells to change their color as directed.

That was four years ago. But is your local paint store currently offering colors such as "Green-Screen Green" or "Windows-Screen-of-Death Blue"? Again, this is probably a result of the technical challenges, which in the case of photo-enforced stratification, includes the contamination caused by the painted surface. That's why the Philips engineers first got it working on glass.

This article may be the first time you have ever heard of "cholesteric LCD panels". Readers may imagine that such LCD panels are used by doctors to display to their patients that their cholesterol levels are too high, and chide them for spending too much time sitting at a computer, or reading a computer periodical. Actually, cholesteric refers to the way in which the liquid crystal molecules are aligned.

Last year, Fujitsu announced that they had developed a flexible LCD using cholesteric technology, which even continues displaying an image without any power supply. The screen was only 3.8 inches across, and is flexible like paper, but cannot be folded. In the same year, Samsung announced a 7-inch display, utilizing high-end plastics, which are thinner and less brittle.

Uses?

There have been many proposals as to how these flexible displays could be put to good use. They could be stitched into all sorts of clothing — with the fronts and backs of shirts and jackets most likely being the first such locations. Smaller screens could be attached to the fronts of ball caps or the shoulders of sports jackets, perhaps displaying the logo and up-to-the-minute game results of a favorite team.

Flexible LCDs would be the best choice for entertainment consoles built into the backs of car seats, especially when the intended audience comprises young children, for whom a display screen made of something other than glass, would be a safer option. Flexible screens would be invaluable if and when cars are designed so that their seats and other large interior components are much more configurable than they are in current vehicles.

A more technical advantage to flexible LCDs, is that they would allow computing to become even more portable, since the computer display could be rolled up, and would also be less fragile and susceptible to damage. Computer displays have been cited as the final remaining impediment to true portable computing, given how all of the other computer components have been either made much smaller or flexible.: For input, speech recognition systems, stylus-based sensitive screens, and roll-able keyboards have already been developed and proven to work. Microprocessors and memory modules are packing more power into smaller spaces. Hard drives are getting smaller, with greater capacities, and may disappear completely with the astounding progress made in flash-based memory.

With flexible display technology, newspapers could become more durable and reusable, in addition to the contents being update-able in real-time, using wireless transmissions from Wi-Fi systems to individual newspapers in the region, based upon user preferences and chosen payment plans. The possibilities for roll-able and dynamic display screens, are limited only by the imaginations of researchers and inventors in countless industries.

Abuses?

Are there any potential downsides to flexible LCDs? Would they be less recyclable than their inflexible counterparts? That naturally depends upon the constituent materials eventually chosen by the manufacturers. Flexible displays would likely be more earth-friendly, given how researchers are now able to control the colors displayed by organic light-emitting diode systems.

Would garish advertising billboards become more prevalent, with overzealous marketing teams trying to squeeze as much of their commercial message into every available surface? Perhaps so, but it might be little different from the current level of such promotion, given how the typical urban center has been inundated with scrolling billboards, paper posters, big-screen TVs showing commercials, and — as a somewhat different form of advertising — gang graffiti.

Would flexible computer displays of all sizes be any better or any worse? The primary difference would be the use of motion, to attract attention. This could make driving more hazardous, as a result of the driver's view being filled with animated images everywhere the driver looks, including the back of the truck in front of him or her.

Most likely some sort of safety standards would be codified as city ordinances, or simply deemed unneeded once computers have taken over the job of driving our vehicles. But that's another story.

Copyright © 2006 Michael J. Ross. All rights reserved.