Polymer dispersed liquid crystal panel with diffraction grating and reflective counter electrode

摘要

Pixel electrodes of a liquid crystal panel are made of a transparent conductive material, while a reflection electrode is formed on a counter substrate. A liquid crystal layer made of liquid crystal/resin composite is interposed between the pixel electrodes and the reflection electrode. Incident light is scattered in the liquid crystal layer or transmits the liquid crystal layer and is reflected by the reflection electrode according to the applied voltage to modulate the light. The pixel electrodes consist for example of two layers of a dielectric layer of thickness of lambda /4 and a transparent conductive layer of thickness of lambda /2. A grating is formed on the reflection electrode at the interface with the liquid crystal. When a voltage is applied to the liquid crystal layer, the refractive index thereof changes to be equal to that of the grating, and the incident light propagates straightly. Otherwise the incident light is diffracted. The liquid crystal panel is used as a light bulb for a projection type television.