COLOR PRE-FILTER FOR SINGLE-PANEL PROJECTION DISPLAY SYSTEM

摘要

A single-panel LCD projection system includes a color prefilter positioned between an illumination system and a multi-color liquid crystal display (LCD). The color prefilter functions to shape the spectrum of illumination provided by the illumination system so as to increase relative panel transmission and to reduce heat absorption by color component filters (e.g., red, green and blue) incorporated in the LCD. The color prefilter is selected to eliminate from or greatly reduce in the illumination light the intensity of certain wavebands that do not materially contribute to generating pure primary colors. A consequence of adding the color prefilter is that the LCD color component filters can be desaturated and the overall total transmission of the projection system can be improved. In one implementation, the color prefilter is able to remove the wavebands of highest absorption by the LCD color component filters before such light strikes the LCD, so that there is less heat build-up in the LCD.