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"Many original equipment manufacturers thought that active-matrix electrophoretic displays were too slow for stylus input or drop-down menus—or even to keep up with a fast typist—but the bottleneck was the controller chip," said Sri Peruvemba, vice president of marketing at E Ink. "The engineers at Epson helped us design a controller chip that proves interactive applications are possible for electrophoretic displays."

With the faster Epson-manufactured controller, E Ink claims that electrophoretic displays can tackle nearly every application now served by LCDs, albeit only in black and white (or a limited number of gray scales). Applications include e-books, newspapers, -notebooks and -dictionaries; tablet PCs; and auxilliary displays for ordinary laptop computers.

Unlike a liquid-crystal display, which must refresh each pixel location about every 15 milliseconds, electrophoretic displays do not require a raster scan of the entire display. Rather, the controller only sends an electrical signal to the pixels that need to be changed. Consequently, the controller that supplies the electrical charge to the substrate can operate on a slower time scale, of about 250 milliseconds per pixel change. The new, speedier controller chip jointly developed by E Ink and Seiko Epson can change the state of up to 16 pixels simultaneously, increasing the perceived speed of the display to be on a par with that of LCDs (about 15 ms).

"We got the fastest typists we could find in our company to try it out, and none of them could type faster than the new controller," said Peruvemba. "We have also tried displaying video and have gotten a response that looks like an LCD, when in fact it is still using the same electrophoretic technology as before."

http://www.eetimes.com/news/latest/s...leID=207400055