Electrophoretic displays include a light-emitting layer, a photoconductive layer, and an electrophoretic layer. The light-emitting layer may be an organic, light-emitting material, or organic, light-emitting diode, which is addressable using a multiplex addressing drive scheme. The impedance of the photoconductive...http://www.google.ca/patents/US6445489?utm_source=gb-gplus-sharePatent US6445489 - Electrophoretic displays and systems for addressing such displays
