JPS5618675A - Liquid crystal display element - Google Patents

Abstract

PURPOSE: To provide a liquid crystal display element in which the diversification of display color and high-crystalloid display are contemplated, by a method wherein a coloring matter having negative dichroism is added to a liquid crystal having positive dielectric anisotropy to form a guest- host liquid crystal which is then enclosed in a liquid crystal cell.

CONSTITUTION: 0.5W90wt% of a negative dichromatic coloring matter (an N-type coloring matter) of formula I [wherein X, Y are radicals represented by various formulas (wherein R₁, R₂ are H, halogen, NO₂, CN, OH, alkyl, alkoxy; R₃, R₄ are H, halogen, CH₃, CF₃, OH, CH₃COO, NO₂, CN, NH₂)] is added to a liquid crystal having positive dielectric anisotropy to form a guest- host liquid crystal 7. For example, in a two-layer cell composed of transparent glass base plates 1, transparent pattern electrodes 2, orientation layers 3, a polarization plate 5 and a reflective plate 6 and sealed 4, the first layer 8 comprises a twist nematic type cell contg. said liquid crystal 7 and the second layer 9 comprises a cell in which a positive dichromatic coloring matter is added to a liquid crystal having negative dielectric anisotropy and which is subjected to a vertical orientation treatment. When only the layer 8 is switched on, the color of the N-type coloring matter is displayed. When only the layer 9 is switched on, the color of the positive dichromatic coloring matter is displayed When both the layers 8 and 9 are switched on, a compound color is displayed.

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