Projection-type multi-color liquid crystal display device

Claim 1

A projection-type liquid crystal multi-color display device, comprising: a liquid crystal panel having a plurality of layers of cholesteric-nematic phase transition type liquid crystals having a positive dielectric anisotropy and a refractive index anisotropy, each of the layers having a layer thickness, the liquid crystals being in, depending on an applied electrical voltage history, either a homeotropic or focalconic texture when a certain electrical voltage is applied to the liquid crystal layer, the liquid crystal layers forming an image composed of homeotropic and focalconic textures by selectively applying different electrical voltage histories and then maintaining said certain electrical voltage at the liquid crystal layer, the refractive index anisotropy of the liquid crystal and the layer thickness of each of the liquid crystal layers being selected so that a light transmitted through each liquid crystal layer is brought to a desired color if a light is incident normal to each liquid crystal layer at a portion thereof in the focalconic texture, while a portion of the liquid crystal layers in the homeotropic texture is transparent and a light transmitted there is not colored; and an optical system for making a light incident almost normal to the liquid crystal panel and forming a projected image of the image of the homeotropic and focalconic textures in the liquid crystal panel on a screen, thereby coloring a light which has been transmitted through a focalconic texture portion of the liquid crystal layers so that the projected image is made a multi-color image.