Patent ID: 6618104
Filing Date: 2003-09-09
Classification: G02B,G02F

Abstract:
An optical device comprising a light transmissive plate-shaped light guide for guiding light incident from an end surface, an optical control layer provided on a lower surface of said plate-shaped light guide through a transparent electrode provided as a first electrode, and a reflection plate made of a light transmissive plate provided on a lower surface of said optional control layer through a transparent electrode provided as a second electrode,wherein said optical control layer is selected from the group consisting of liquid crystal particles dispersed in a polymer resin area, a polymer dispersed liquid crystal comprising polymer resin particles dispersed in a liquid crystal, and a polymer dispersed liquid crystal in which a respective polymer resin area and a liquid crystal area are continuous, wherein said liquid crystal has a structure periodically distributed in the form of a diffraction grating, and wherein said optical control layer is made of a reverse mode holographic polymer dispersed liquid crystal which is constructed by dispersing a low molecular-weight liquid crystal in a liquid crystalline polymer, and changes in diffraction ability by an electric field applied by said first electrode and said second electrode so that said optical control layer becomes a birefringent thin film in the absence of any applied electric field, while said optical control layer becomes said diffraction grating for functioning as a hologram when an electric field is applied.