In display device comprising a reflection element whose display state is changed by the application of the electric field, and a photoconductive layer whose conductivity is changed by the application of light, a drive voltage is applied to the reflection element and the photoconductive layer, and writing...http://www.google.com.au/patents/US20050179678?utm_source=gb-gplus-sharePatent US20050179678 - Method and apparatus for driving display device
