(E Ink Corporation, Cambridge, MA, www.eink.com) Founded in 1997, E Ink makes electronic paper display (EPD) subsystems for handheld devices using E Ink Vizplex Imaging Film. Although initially monochrome, color is expected. Products include seven-segment display film for smart cards, shelf labels and the like and partially complete substrates for e-books.

Long Battery Life, High Resolution and Flexible
EPD screens can run up to 30 times longer than LCD screens without recharging. Unlike LCDs, which need constant refreshing, once an EPD display is rewritten, it holds its content indefinitely.

The resolution of EPD devices in production is 167 dpi, compared to 96-120 dpi on LCD screens. Since EPD supports up to 400 dpi, the resolution limitation is in the device electronics. In 2008, Epson revealed an EPD prototype at 385 dpi (see image below). E Ink's seven-segment displays are made on flexible plastic backplanes, and the larger glass substrates are expected in plastic in the future.

Microcapsules Filled with Fluid and Particles
The E Ink Vizplex film is made of microcapsules filled with fluid and many charged black and white particles composed of ink pigments. The microcapsules are coated on the film and laminated to the top electrode. Row and column drivers are attached, and the module is shipped to customers who add the bottom electrode. Sandwiched between the electrodes, the black and white particles are drawn to the viewing surface when the opposite charge is applied.

The EPD technology stems from the early 1990s when Dr. Joseph Jacobson of MIT Media Labs improved upon an earlier approach from Xerox PARC that used larger beads and more power. E Ink Corporation was founded to refine the MIT technology. See electronic paper and electrophoresis.