Patent ID: 7034783

Claim:
An electro-optic display comprising: a layer of a bistable electro-optic medium; a plurality of pixel electrodes disposed on one side of the layer of electro-optic medium, at least one non-linear element associated with each pixel electrode; pixel drive means arranged to apply voltages to the pixel electrodes via the non-linear elements; a common electrode on the opposed side of the layer of electro-optic medium from the pixel electrodes; and common electrode control means arranged to apply voltages to the common electrode, the display having a writing mode, in which the pixel drive means applies at least two different voltages to different ones of the pixel electrodes, thereby writing an image on the electro-optic medium, and a non-writing mode in which the pixel drive means controls the voltages applied to the pixel electrodes so that any image previously written on the electro-optic medium is substantially maintained, the common electrode control means being arranged to apply to the common electrode a first voltage when the display is in its writing mode and a second voltage, different from the first voltage, when the display is in its non-writing mode.