| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection optical system that can be manufactured more easily, and to provide an image projection apparatus comprising the projection optical system.SOLUTION: A projection optical system 14 comprises a rotation symmetrical optical system 13 and a rotation asymmetrical optical system, and projects light from an object to a target projection surface. In the projection optical system 14, the rotation asymmetrical optical system comprises at least one optical element having a rotation asymmetrical reflecting face. The rotation asymmetrical reflecting face is a curved face expressed as a function of a two-dimensional coordinates. Additionally, in an area of the curved face irradiated with the light, a partial differential coefficient of the function related to the coordinates in at least one direction in the two-dimensional coordinates is a positive or negative value. An image projection apparatus for projecting an image to the target projection surface comprises the projection optical system. |
