Patent ID: 8610661

Claim:
An electrophoretic device comprising a drive unit and a plurality of pixel cells, arranged in an array, each cell comprising drive electrodes and an electrophoretic medium which is responsive to an electric field applied between said electrodes by the drive unit, said electrodes comprising a viewing electrode, which is situated at a viewing area of the cell, such that in a first mode, when the electrophoretic medium is attracted to the viewing electrode, the transmission of light through the cell is obstructed by the electrophoretic medium, and a collector electrode, situated outside the viewing area, such that in a second mode, when the electrophoretic medium is attracted to the collector electrode, the obstruction is reduced, wherein the viewing electrode is divided into at least a first and a second viewing sub-electrode, wherein the first and second viewing sub-electrodes are disposed both on the same surface of the pixel cell in a substantially co-planar arrangement and toward opposite lateral edges of the cell such that a free area in said viewing area is formed by a lateral separation between adjacent edges of the first and second viewing sub-electrodes, wherein the free area is free of any viewing electrode and viewing sub-electrode; and the drive unit is configured to apply, when the cell is to enter the first mode, a voltage pulse between the first and second viewing sub-electrodes, such that said electrophoretic medium moves into said free area.