Methods for driving bistable electro-optic displays, and apparatus for use therein

A method of driving a bistable electro-optic display, the display comprising a layer of a bistable electro-optic medium, first and second pixel electrodes disposed on one side of the layer of electro-optic medium and defining first and second pixels of the display, and a common electrode disposed on the opposed side of the layer of electro-optic medium, the method comprising:

• (a) applying a first common electrode voltage to the common electrode, applying a first gamma voltage to the first pixel electrode, and applying the first common electrode voltage to the second pixel electrode, thereby applying an electric field in one direction to the first pixel of the display, and substantially no electric field to the second pixel;
• and
• (b) applying a second common electrode voltage, different from the first common electrode voltage, to the common electrode, applying the second common electrode voltage to the first pixel electrode, and applying a second gamma voltage to the second pixel electrode, thereby applying substantially no electric field to the first pixel of the display, and an electric field in the opposed direction to the second pixel of the display.

A bistable electro-optic display comprising a layer of a bistable electro-optic medium, first and second pixel electrodes disposed on one side of the layer of electro-optic medium and defining first and second pixels of the display, a common electrode disposed on the opposed side of the layer of electro-optic medium, and a display controller for controlling the voltages applied to the first and second pixel electrodes and the common electrode, the controller being arranged to:

• (a) apply a first common electrode voltage to the common electrode, apply a first gamma voltage to the first pixel electrode, and apply the first common electrode voltage to the second pixel electrode, thereby applying an electric field in one direction to the first pixel of the display, and substantially no electric field to the second pixel;
• and
• (b) apply a second common electrode voltage, different from the first common electrode voltage, to the common electrode, apply the second common electrode voltage to the first pixel electrode, and apply a second gamma voltage to the second pixel electrode, thereby applying substantially no electric field to the first pixel of the display, and an electric field in the opposed direction to the second pixel of the display.