Display controller for bistable electro-optic display

Abstract

There are provided display controllers and driving methods related to those described in US Published Patent Application No. 2013/0194250. These include (a) a display controller having an update buffer, means for removing from the update buffer pixels not requiring updating, and means to ensure that pixels having certain special states are not removed from the update buffer; (b) a method of driving a bistable display wherein, in a pixel undergoing a white-to-white transition and lying adjacent another pixel undergoing a visible transition, there is applied to the pixel one or more balanced pulse pairs and at least one top-off pulse; (c) a method of driving a bistable display by overlaying a non-rectangular item over a pre-existing image content and then removing the item, where only pixels in the region of the item perform transitions (including self-transitions); and (d) a method of driving a bistable display in which a proportion of background pixels not undergoing an optical change are subjected to a refresh pulse to correct optical state drift.

1 . A method of driving a bistable electro-optic display comprising overlaying an item over pre-existing text or image content followed by removal of the item, wherein the item includes at least one transparent region, and wherein only pixels in the non-transparent regions of the item perform transitions. 
     
     
         2 . The method of  claim 1 , wherein the item is an icon, a cursor or a menu. 
     
     
         3 . The method of  claim 1 , wherein the item is non-rectangular. 
     
     
         4 . The method of  claim 1 , wherein the bistable electro-optic display comprises electrically charged particles in a fluid, wherein the particles move through the fluid under an influence of an electric field. 
     
     
         5 . A display controller or electro-optic display arranged to carry out the method of  claim 1 .