| 摘要 |
<p>PURPOSE: To simplify constitution and to reduce the loss of light in the entire optical path by making mutually tilted three mirror surfaces cross at an intersection, dividing the pupil of a projection objective lens into the three segments of an almost equal area and passing through only one of three partial light fluxes to the respective segments. CONSTITUTION: The optical axes of the three partial light fluxes 14R, 14G and 14B are mutually tilted so as to be crossed at one common intersection 16. The three mirror surface 17, 17' and 17" are crossed at the intersection 16 and they are mutually tilted so as to turn the three partial light fluxes 14R, 14G and 14B to a common direction matched with the optical axis of the projection objective lens 18. The formation of the three partial light fluxes 14R, 14G and 14B corresponds to a normal projection light beam route and a light source is image formed in the pupil 19 of the projection objective lens 18 by an illumination system present near liquid crystal light valves 15R, 15G and 15B. Thus, light beams are geometrically gathered, the constitution is simplified and the loss of the light is reduced.</p> |
