A light emitting device capable of displaying grey scale is provided. The device has a pixel having a plurality of bistable subpixels. Each subpixel has an ON state and an OFF state. A different power line is coupled to each bistable subpixel. Circuitry that can individually modulate the pulse width...http://www.google.de/patents/US7053412?utm_source=gb-gplus-sharePatent US7053412 - Grey scale bistable display
