Electro-optical device

摘要

The disclosed invention relates to an electro-optical device for use with a facsimile printer, telecopier, etc., designed to accommodate line-at-a-time output of picture information with the aid of an electrically controllable electro-optical substrate made from a transparent electro-optical material, with the optical effect being controlled by applying a voltage between two control electrode arranged next to each other on the substrate. According to a preferred embodiment of the invention, within the area (4) of the substrate (1) to be controlled, and in addition to the control electrodes (2,3), there is provided at least one additional electrode (7) which may be common to several such areas (4), with each area (4) to be controlled having a corresponding opening (8) in the additional electrode (7) and the two control electrodes (2, 3) being spaced apart from each other on one side of the substrate (1) and the one or more additional electrodes (7) being arranged on the opposite side of the substrate. By applying a suitable voltage to the additional electrode (7), the electro-optical effect of the substrate can be varied within the areas (4) independently of the control (switching) voltage applied to the control electrodes (2, 3). Thus, various grey values can be provided; alternatively, a particular substrate (1) can be matched or adapted to one from another production batch and the control voltages can be kept to minimal levels.