US Patent 9672766 Methods for driving electro-optic displays

A bistable electro-optic display having a plurality of pixels each of which is capable of displaying at least three optical states, including two extreme optical states, is driven by the method comprising a first drive scheme capable of effecting transitions between all of the gray levels which can be displayed by the pixels; and a second drive scheme which contains only transitions ending at one of the extreme optical states of the pixels.