System for eliminating secondary images in rear projection systems

摘要

A secondary image suppression system (SISS) for minimizing secondary ghost images in a screen assembly for a rear projection system. The secondary image suppression system includes a circular polarizing assembly positioned to receive light from a rear projection lens of a rear projection system. The circular polarizing assembly includes a linear polarizer and a quarter wave retarder. The linear polarizer and the quarter wave retarder are serially positioned relative to each other and are assembled with a high power Fresnel lens using index matching media such that internal reflections are minimized. The high power Fresnel lens is positioned to receive output from the circular polarizing assembly. During use, light from a projection lens of a rear projection system is introduced through the circular polarizing assembly and through the high power Fresnel lens toward a viewing screen. Any significant secondary ghost images are eliminated by the circular polarizing assembly. The SISS may be combined with a high contrast screen assembly to improve high ambient contrast while avoiding the necessity for beaded films or other structured screens that could cause viewing artifacts.