| 摘要 |
PROBLEM TO BE SOLVED: To produce an illuminator and a projection type display device capable of obtaining bright light by effectively utilizing light emitted from a light emitting part. SOLUTION: An optical element 204a having a special shape which reflects light which is emitted from a light source part 110 and transmits a polarizing beam splitter is provided in this device. Even light which is not separated and selected in the splitter can be returned to the light source part. At this time, since the light is reflected in directions shifted from incident directions, they are never returned to a first light emitting point P1 but they are reflected again on other parts. Consequently return light is never obstructed by a light emitting part 111 and, thus, the utilization factor of light is enhanced. |
