US Patent 9620048 Methods for driving electro-optic displays

An electro-optic display has a plurality of pixels, each of which is capable of displaying two extreme optical states and at least one intermediate gray level. Each pixel is driven from an initial intermediate gray level to one extreme optical state and then to a first desired intermediate gray level, so producing a first image on the display. The pixel then remains at this first desired intermediate gray level for a finite length of time. The pixel is then driven from this first desired intermediate gray level to the opposed extreme optical state and then to a second desired intermediate gray level, so producing a second image on the display.