Patent ID: 7474301

Claim:
A method of driving a plurality of pixels constituting a multi-gradation electro-deposition display apparatus by selectively causing deposition and/or dissolution of a metal contained in a layer between two electrodes by impressing a predetermined voltage between the electrodes of each pixel, said method comprising: for each of a plurality of pixels, applying a voltage pulse or alternating current voltage having an amplitude of not more than a threshold to the pixel and determining a resulting current and/or resistance based upon the applied voltage pulse or alternating current voltage to the pixel, and selectively applying a writing pulse or an erasing pulse based on the current and/or resistance depending upon a desired coloration state for the pixel, and further wherein by applying said writing pulse or erasing pulse, the density of each said pixel is controlled, thereby causing the gradation of said pixel to shift to a whiter or a blacker level of the multi-gradation display, wherein at least some of the pixels receive a writing pulse and at least some of the pixels receive an erasing pulse in order to display information.