JUNE 6--E Ink Corp. (Cambridge, MA; www.eink.com), developer and marketer of electronic ink technology for paper-like displays, has demonstrated very-thin active-matrix displays. Prototypes were first exhibited at last month's Society for Information Display (SID) Symposium, Seminar, and Exhibition, in Boston, MA.
E Ink has demonstrated two display sizes targeting highly portable, rugged information appliances. At less than half the thickness of a credit card, these development prototypes have a total display thickness of just 0.3 mm. Traditional active-matrix display panels measure 2 mm thick and often require a backlight for a combined thickness of 4 mm or more. E Ink's prototypes are roughly 90% thinner and lighter than typical glass-based, liquid-crystal displays.
Active-matrix displays that are commercially available today are produced with two sheets of thick, fragile glass. Fracture of glass substrates is often reported as the leading cause of field failure of portable devices. In contrast, E Ink's flexible displays are constructed by combining a thin, shatterproof steel foil transistor substrate with E Ink's paper-like electronic ink display material coated onto a plastic face sheet. Steel foil was chosen as the transistor backplane material because of its overall performance from initial transistor processing through final display use. "The beauty of this technology is that it is compatible with existing display production technology, cutting years off time to market," said Michael McCreary, vice president of research and development at E Ink.
Unlike other flexible display or ultrathin display solutions, E Ink's novel backplane technology is practical; it is based on readily available substrate materials and well-established semiconductor-process technologies. Combined with E Ink's electronic-ink front-plane film, E Ink now offers a complete technology platform for flexible, paper-like displays. These advanced display products are expected to reach consumers in 2004--2005.
The first display prototype is targeted at card-sized mobile applications such as SmartCards and cell phones. With a 1.6-in. diagonal and 80 pixels per inch (ppi), the display has a resolution of 100 x 80 pixels. The second display prototype measures 3.0 in. diagonally and is targeted at hand-held devices. These include PDAs, two-way pagers, and novel communication devices such as mobile display appliances or hand-held monitors that are peripheral to cell phones or other wireless 'servers.' The resolution of this display is 240 x 160 with 96 ppi.
E Ink envisions the unveiled prototypes will enable new design freedom for device makers - such as curved surfaces and bendability--while providing end users with highly portable and rugged information appliances. "E Ink is now working with leading device makers to integrate our electronic ink and backplane technologies into ultrathin and flexible displays for next-generation portable devices," stated Dan Button, vice president of business development at E Ink.