Bildprojektions-System

摘要

A polarizer comprising; a substrate transparent to a light of actual use and optical thin films (25) of a higher refractive index than that of said substrate (24) deposited on both surfaces of said substrate. The substrate (24) is arranged so as to receive the incident light obliquely thereto. When the incident angle and the thickness of the optical thin films (25) are optimally selected, the transmittance for the P polarized light can be made approximately 100 %, while that for the S polarized light very small. The polarizer can extract a substantially linearly polarized light from natural light. A projection image display system has the polarizer as its pre-polarizer. The polarizer is also useful for infrared radiation.