Electronic paper is catching up with the real thing

"I no longer want my MTV"
Bart Simpson


Paper chase
From Economist.com
Electronic paper is catching up with the real thing




AN INVENTOR meets a venture capitalist in a bar. He pulls out of his pocket something that looks like a grubby handkerchief, straightens it out on the bar top, and begins his pitch for $10m of venture money.

It's a video display that can be furled, folded or rolled up into a ball, the inventor enthuses. He shows how it can be viewed from any angle, is easy to read in bright sunlight, has a contrast ratio better than a laptop's liquid-crystal display (LCD), is light and portable, and can run for months without being recharged. It will change the way we view the world, swears the wide-eyed inventor. "Naw, it's all been done better and cheaper before," says the unimpressed VC, as he crumples the newspaper he was reading and tosses it into the bin.

Ink on paper has evolved over the millennia to become the easiest medium to read and the most efficient means for conveying information. And despite all the talk about paperless offices, computers have contributed mightily to today's deluge of printed material instead of helping diminish it. But that hasn't stopped researchers around the world from trying to replicate print on paper electronically.

The one thing going for e-paper, which the dead-tree version can't hope to match, is its programmability. Imagine a newspaper that could be updated as events developed during the day. Think of a book that could change its contents after you'd finished reading it. How about a laptop-sized screen that unfurled from your mobile phone so you could watch TV while strap-hanging to work? What if your tee-shirt could flash intimate messages to attractive passers-by?

Sony is the latest in a long line of gadget-makers to flaunt a paper-like electronic display. The flexible 2.5-inch display it demonstrated a couple of weeks ago was notable for two reasons: it offered full-motion video and was in living colour.

E Ink Corporation



In some ways, Sony is playing catch-up here. LG Philips, a joint venture between LG of South Korea and Philips of the Netherlands, has been showing off a 14-inch colour screen that's flexible enough to wrap around a lamp post. Prime View International of Taiwan has something similar. So does Samsung of South Korea and both Seiko Epson and Fujitsu of Japan, as well as a handful of start-ups in Britain and America. But until recently, few of them were able to display colour video properly.

While making flexible displays in monochrome has been difficult, adding colours and making them switch fast enough for full-motion video has been a tougher nut to crack. The trick to making such furlable displays has been to fabricate the electrode arrays for switching the display's millions of picture elements ("pixels") from either conducting plastics or extremely thin metal foil. Fortuitously, the recent improvement in plastic electronics for ink-jet printers has invigorated the whole of the e-paper business.

Like real paper, e-paper has to be both highly reflective and passive-ie, it should need no juice for backlighting or for maintaining the image. The best way to do that is to use a medium that's bi-stable. Like a tossed coin, a bi-stable material can flip between two possible states-and then remain stable, and require no energy, in one or the other state until flipped again.

The first attempts to devise a bi-stable ink were made 30 years ago at Xerox's legendary Palo Alto Research Centre in California. Called Gyricon, the technology was based on a transparent silicone sandwich with millions of tiny polyethylene spheres floating in oil between the upper and lower surfaces. Each of the tiny beads, less than a hair's width in diameter, was black on one side and white on the other, with each hemisphere carrying an opposing electric charge. When an external charge was applied to an electrode array on the upper surface of the sandwich, the beads floating beneath them rotated promptly to reveal either their white or black sides-spelling out words and images, depending on the pattern of surface electrodes switched on or off.

Nowadays, a Xerox subsidiary called Gyricon LLC sells its SmartPaper-the polarised-bead form of e-paper-as reprogrammable displays for draping inside retail stores, hotels, conference centres and colleges. The flexible signs are connected wirelessly to computerised databases so they can be changed with the click of a mouse.

The bi-stable technology that has progressed the furthest, however, is a refinement perfected at the Massachusetts Institute of Technology (MIT) in the early 1990s. This uses tiny microcapsules filled with electrically-charged particles of white titanium dioxide suspended in an oily solution of black dye. The capsules themselves are trapped in a liquid polymer that's sandwiched between two arrays of electrodes.

When a negative charge is applied to individual electrodes, the titanium-dioxide particles move to the top of the microspheres and make that part of the display appear white. As with the Gyricon, the pattern of electrodes switched on or off determines the image on the display.

E-Ink, the company spun off from MIT to commercialise the idea, supplies such displays to electronics firms around the world, including LG Philips, Samsung, Motorola and Prime View as well as Sony. The first e-book reader launched by Sony in 2004 used an E-Ink display with electronics supplied by Philips.

Sony's latest announcement promises to bring e-paper even closer to everyday use. This time the device appears to be a home-grown development. Unlike the electrophoretic displays used in E-Ink's products, which rely on charged particles being physically moved by an electric field, Sony's new imaging device uses an organic electroluminescence display (OLED). Such displays emit light in response to an electric current or field being passing through them.

OLEDs generally use a glass substrate, or backing material. But Sony has found a way of forming the organic transistors for switching the pixels on and off on a flexible plastic substrate. The 2.5-inch prototype is little thicker than a sheet of actual paper and weighs about the same without its associated electronics.

Don't expect such a clever innovation to be wasted on something as prosaic as a portable reader for e-books. Apple's multimedia iPhone may be the gadget du jour, but Sony may trump it with an all-singing-and-dancing gizmo, built around a foldable display for downloading television, which can run for days without recharging. Now that's something not to be sneezed at.

LG Philips Launches Bendable Color E- Paper

BoSacks Speaks Out: This is just a small article and a heads-up on the four color future of information distribution. E-paper is continuing to make great strides. This primitive device is just another shot in the very beginning of a soon to be vibrant industry. The technology will get better and better and the cost of manufacturing will plummet. We are not there yet, but soon, easy to read, quality e-paper will be everywhere.

"Only government can take perfectly good paper, cover it with perfectly good ink and make the combination worthless."
Milton Friedman (American Economist, b.1912)


LG Philips Launches Bendable Color E- Paper
by Matthew Broersma,
Techworld
http://www.pcworld.com/article/131798-1/article.html? tk=nl_dnxnws

LG.Philips LCD on Sunday took the wraps off the world's first A4-sized color "e-paper" display, following up on its black and white display of the same size a year ago.

The 14.1-inch, 4,096-color display is paper-thin and flexible, and can be viewed from up to a 180-degree angle, meaning images remain crisp even when the display is twisted around, the company said.

The image is designed to be comparable to print quality, LG.Philips said. The display is less than 300 micrometers thick, and only uses power when the image changes.

E-paper is a concept designed to open up new frontiers in the world of LCD displays and to replace paper in some cases. A number of companies have debuted prototypes of such lightweight, thin, flexible displays, including Taiwan's Prime View International (PVI) and Japan's Seiko Epson.

LG.Philips' version of the technology uses a substrate that arranges Thin-Film Transistors (TFT) on metal foil rather than glass, making the display flexible and allowing it to return to its original shape after being bent. The latest display includes a color filter coated onto the plastic substrate.

The company's development process for the color display centered on overcoming processing difficulties related to the lack of heat resistance in metal foil and plastic substrates.

That meant developing processing technology that minimizes panel deformation and prevents circuit structure change during high-temperature processes, as well as research into the lamination technology and the design of the transistors and color filter, the company said.

PVI recently introduced Vizplex, an e-paper technology that, like LG.Philips' displays, uses electronic ink from E-Ink. PVI's smaller displays, between 1.9 inches and 9.7 inches, are due out this summer and are designed for mobile phones, music players, bulletin boards and electronic books.

Seiko Epson introduced a high-resolution, A6-sized e- paper display using E-Ink and a manufacturing technique called surface-free technology by laser annealing (SUFTLA).