Patent ID: 7800580
Filing Date: 2010-09-21
Classification: G09G

Abstract:
1. An electrophoretic display comprising: at least one pixel cell having drive electrodes and an electrophoretic media that is responsive to an electric field applied between said drive electrodes; and a drive unit arranged to provide said at least one pixel cell with a drive signal switchable between a monochrome drive scheme and a grayscale drive scheme, said monochrome drive scheme involving drive signals providing for only two extreme optical pixel states, and said grayscale drive scheme involving drive signals providing for said two extreme optical pixel states and at least one additional, intermediate pixel state between said two extreme optical pixel states, wherein said grayscale drive scheme provides drive signals for said two extreme optical states that are different than said monochrome drive scheme for said two extreme optical states, and wherein said drive unit furthermore is operative to apply a transition drive signal when switching from said grayscale drive scheme to said monochrome drive scheme, said transition drive signal being separate from signals applied during either of said monochrome drive scheme and said grayscale drive scheme and being arranged to counteract the build-up of remnant DC voltage in the pixel cell.