| 摘要 |
PROBLEM TO BE SOLVED: To obtain a novel projection optical system which can project a projection image of proper quality, on a large screen with a short full length, by combining a lens system with a concave mirror. SOLUTION: The optical system enlarges and projects an image displayed on an image display surface IP onto a projection surface PS. The optical system includes the lens system L, having a plurality of lenses and one or more curved mirrors. After emission of light from the lens system L toward the projection surface side, the light firstly comes onto the concave surface of the mirror surface MS of the curved mirror. The optical system satisfies a condition: 20<OAL/Y<30, where OAL is a distance from the image display surface IP to the curved mirror surface MS nearest to the projection surface side along the optical axis shared by the largest number of lenses among optical axes of lenses constituting the lens system L, and Y is the distance, up to the image display surface end portion farthest from the optical axis shared by the largest number of lenses within the image display surface IP. COPYRIGHT: (C)2009,JPO&INPIT |
