JPS5666827A - Liquid crystal cell for color display - Google Patents

Abstract

PURPOSE: To obtain a color display of a bright background and less power consumption, by forming a liquid crystal layer which has thickness of the critical value or more of the liquid crystal in the display part, and has thickness of less than the critical value in the nondisplay part, by use of a specific guest-host type liquid crystal layer.

CONSTITUTION: Thickness of the liquid crystal layer 5 which has added two-colored coloring matter (guest) to a host of the liquid crystal which can be mutually converted from the cholesteric liquid crystal layer to the nematic liquid crystal layer, depending on the electric field operation is made d₁ which is thicker than that of the critical value corresponding to the pitch of the spiral structure of liquid crystal, in the display part of the electrodes 2, 2', and it is made d₂ which is less than the critical value, in the nondisplay part between the insulation films 3. A thin film such as lecithin, etc. is provided on the surface of the insulation film 3 and the electrodes 2, 2' so that the liquid crystal molecular long axis can be oriented vertical ly. Since the thickness is large in the display part, the liquid crystal is colored by the spiral structure except the part near the surface of the electrodes 2, 2' when voltage is not applied, but when voltage is applied, the whole part is vertically oriented and becomes colorless in the same way as the nondisplay part. Accordingly, a color display can be executed by applying voltage to only the electrodes 2, 2' which require no display.

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