Methods for driving electro-optic displays
An electro-optic display having a plurality of pixels is driven from a first image to a second image using a first drive scheme, and then from the second image to a third image using a second drive scheme different from the first drive scheme and having at least one impulse differential gray level having an impulse potential different from the corresponding gray level in the first drive scheme. Each pixel which is in an impulse differential gray level in the second image is driven from the second image to the third image using a modified version of the second drive scheme which reduces its impulse differential The subsequent transition from the third image to a fourth image is also conducted using the modified second drive scheme but after a limited number of transitions using the modified second drive scheme, all subsequent transitions are conducted using the unmodified second drive scheme.
1. An electro-optic display comprising a bistable electro-optic medium, at least two electrodes disposed adjacent the bistable electro-optic medium and arranged to apply an electric field to the medium, a display controller for controlling the potentials on the at least two electrodes, and a host controller arranged to supply video information to the display controller, the display controller comprising a frame buffer having a rotating set of image buffer regions which allow the host controller to write images to the frame buffer, the display controller being arranged to retrieve and update the display with the latest whole video frame image written by the host controller, the display controller being arranged to store:
an Image Buffer Read Pointer;
an Image Buffer Write Pointer;
an Image Buffer Empty Flag;
a Programmable Image Buffer Nearly Empty Flag; and
an Image Buffer Latest Image Pointer, which marks the location of the last complete video frame image written to the memory by the host controller and the display controller configured to retrieve and update the display with this last complete video frame image.
2. A display according to claim 1 wherein the pixels of the display are partitioned into interlaced regions each of which is updated at a time offset from the other regions.