Patent ID: 9703178
Date: 2017-07-11
CPC Classifications: G03B

Claim:
1. A projector comprising: a light emitting diode (LED); a spatial light modulator; an illumination system that receives light from the LED and illuminates the spatial light modulator; and a projection lens that forms an image by the light from the spatial light modulator, wherein the LED has a light emitting region as an area light source, wherein the illumination system includes a rod integrator, the rod integrator being arranged so that an entrance plane of the rod integrator faces the light emitting region, and so that a size of the entrance plane of the rod integrator is smaller than a size of the light emitting region, and wherein when illumination efficiency is defined as an efficiency of capturing light from the light emitting region with the rod integrator multiplied by an efficiency of capturing light from the rod integrator with the projection lens, then the size of the entrance plane of the rod integrator is set so that an illumination efficiency when the set size is used is higher than an illumination efficiency when the size of the entrance plane of the rod integrator is the same as the size of the light emitting region.