Projection optical system

摘要

A projection optical system is disclosed with which undistorted images can be obtained at any image position within a specification range, and whose projection angle can be changed. The projection optical system includes a plurality of optical elements and a first optical system constituted by at least one of the plurality of optical elements having the ability to form an image with light onto a predetermined surface different from the projection surface. A projection image of the original image can be moved by rotating a first optical element of the plurality of optical elements substantially around a center of an exit pupil position of the first optical system as the rotation center.