PRISM FOR PROJECTION OPTICAL SYSTEM AND OPTICAL SYSTEM HAVING SAME

摘要

A prism for a projection optical system included in a projector including an illumination light source, an illumination optical system, and a projection optical system, includes: a first surface that totally reflects a beam of one of the illumination light and the projection light and transmits a beam of the other; and a second surface that is opposed to the first surface with an air gap therebetween and transmits a beam passing through the first surface, wherein the first surface has an antireflective film having an average reflectivity of a s-polarized reflectivity and a p-polarized reflectivity at a center angle of a transmitted beam of 2% or lower in three wavelength ranges including a first wavelength range of blue, a second wavelength range of green, and a third wavelength range of red.

主权项

1. A prism for a projection optical system included in a projector including: an illumination light source configured to emit laser light rays of blue, green, and red; an illumination optical system configured to guide illumination light from the illumination light source to an image display device; and a projection optical system configured to project projection light from the image display device onto a screen through a projection lens, the prism for a projection optical system comprising:
a first surface that totally reflects a beam of one of the illumination light and the projection light and transmits a beam of the other; and a second surface that is opposed to the first surface with an air gap therebetween and transmits a beam passing through the first surface, wherein the first surface has an antireflective film having an average reflectivity of a s-polarized reflectivity and a p-polarized reflectivity at a center angle of a transmitted beam of 2% or lower in three wavelength ranges including a first wavelength range of blue, a second wavelength range of green, and a third wavelength range of red.