Start-up reveals the skinny on screens

Start-up E Ink is demonstrating a prototype of a flexible computer screen that's half as thick as a credit card.

With its "electronic ink" technology, the Cambridge, Mass., company is shooting for displays that are thinner and more durable than current active-matrix liquid-crystal displays. Such displays are used in cell phones and handhelds.

Electronic ink is based on a microcapsule: an electrically sensitive white chip that floats in a ball full of black dye--on a tiny scale, it's similar to the low-tech Magic 8-Ball toy. The chip rises or falls in the dye depending on an electrical charge. Many microcapsules are sandwiched between a piece of steel foil and a piece of clear plastic, and, unlike LCDs, they don't need to be backlit for an image to be visible.

The absence of a lamp for backlighting, and the use of steel foil, are what allow the screens to be significantly thinner than LCDs, which typically use a lamp and two sheets of glass, the company said.

Prototypes of the new displays are 0.3 millimeters thick, or about half the thickness of a credit card. Traditional active-matrix displays are about 2mm thick, according to the company.

Aside from being svelte, displays using the electronic ink technology tend to consume less power than LCDs, the company said. Unlike LCDs, they don't require a continuous supply of power to render images: Once the microcapsules are electrically charged, they can hold the image without more power.

E Ink plans to license its technology to manufacturers and expects consumers to have the displays in hand by 2005.

While the technology is still far from consumers' reach, the prototypes indicate that the company is making progress, said Kim Allen, an analyst with research firm iSuppli/Stanford.

"These prototypes demonstrate proof of principle. It shows that it's possible, and (that's) a big step," Allen said.

Company representatives could not be reached for comment on details such as pricing and manufacturer interest.

The start-up has two prototypes using the active-matrix technology. One measures 1.6 inches diagonally and is meant for cell phones, and the other, which measures 3 inches diagonally, is suited for handhelds.