Patent ID: 9201282
Filing Date: 2015-12-01
Classification: G02F,G09G

Abstract:
1. An electrophoretic display device comprising a pixel comprising charged pigment particles for determining a pigmentation of the pixel, the pixel comprising an aperture area being a visible part of the pixel determining the pigmentation of the pixel, the pixel further comprising a storage area for storing the charged pigment particles away from the aperture area, the pixel comprising an accumulation electrode and a field electrode, the accumulation electrode being arranged at the storage area for accumulating the charged pigment particles away from the aperture area, and the field electrode occupying a field-electrode area being at least a part of the aperture area of the pixel, the charged pigment particles being movable between the accumulation electrode and the field electrode under control of an electric field, a dimension of the charged pigment particles being selected sufficiently small to obtain a uniform distribution of charged pigment particles across the field-electrode area for generating a substantial homogeneous pigmentation at the part of the aperture of the pixel occupied by the field electrode, the sufficiently small charged pigment particles having a repellent force to prevent the forming of a rim of charged pigment particles at or around the field-electrode edges, the charged pigment particles comprise nano-particles having a particle size below 400 nanometers, wherein the accumulation electrode and the field electrode are arranged in a configuration wherein the accumulation electrode is arranged at a top side of the pixel to block viewing of accumulated particles in the storage area through the aperture area of the pixel, and the field electrode is located at an opposite bottom side of the pixel to thereby define a vertical space with the accumulation electrode and provide at least partly vertical movement of the charged particles therebetween; and wherein the electrophoretic display device comprises a plurality of pixels, each comprising the aperture area comprising the field electrode, and each comprising the storage area comprising the accumulation electrode, the accumulation electrodes of the plurality of pixels being coupled to form a common accumulation electrode for the plurality of pixels, the common accumulation electrode omitting a need for a barrier between the plurality of pixels; and wherein a part of the common accumulation electrode that is arranged adjacent to the field electrodes of adjacent pixels is shared between said adjacent pixels in such a manner that said part of the common accumulation electrode is configured to accumulate charged pigment particles corresponding to both adjacent pixels.