POLYMER-DISPERSED LIQUID-CRYSTAL LIGHT VALVES FOR PROJECTION DISPLAY

We describe the polymer-dispersed liquid crystal light valve (PDLCLV) using a polymer-dispersed liquid crystal (PDLC) film and a Bi12SiO20 ( BSO) photoconductive crystal. The PDLCLV has many features suitable fo r large screen displays, such as no polarizer requirement, a high tran smittance (72 to 78%) and high extinction ratio (146:1 to 178:1) in th e entire visible wavelength, short rise/decay times (3/5 to 14/15 ms), and a high resolution (34 lp/mm). We discuss the light scattering and modulation characteristics of the PDLC film; photoconductive characte ristics of the BSO crystal; and the design, fabrication method, and op tical input/output characteristics of the PDLCLV. We also describe the configuration and image display characteristics of a monochrome proje ction-type display consisting of the PDLCLV as an image converter, an active matrix liquid crystal panel with thin film transistors as an im age source, and a 1-kW xenon arc lamp as a reading light source.