PROJECTION OPTICAL SYSTEM AND PROJECTOR

WIPO Patent Application WO/2017/195561

A1

Provided is a projection optical system that enlarges an image to be displayed on an image display surface to an angle-of-view of at least 70 degrees and projects such image, the projection optical system being a fixed focal length lens or a zoom lens having, in order from the enlargement side, a first optical system and a second optical system on the same optical axis. The second optical system forms an intermediate image of the image. The first optical system enlarges and projects the intermediate image. Positive lenses are positioned at each of the enlargement side and the reduction side of the intermediate image so as to be adjacent to each other. The fixed focal length lens or a zoom lens at the wide angle end satisfies conditional formula 0.4