Patent ID: 8419191
Filing Date: 2013-04-16
Classification: G02B,G03B

Abstract:
1. A projection optical system enlarging images on an image displaying surface, and projecting enlarged images onto a projection surface, the optical system comprising: a lens system including a plurality of lenses and a curved mirror, wherein light flux of enlarged image shooting out from the lens system to the projection screen is incident onto a concave surface of the curved mirror first of all; and a distance OAL and a distance Y satisfy a requirement the distance OAL being present between the image displaying surface and a surface of the curved mirror nearest the projection surface and along an optical path shared by most lenses of the lens system, and on the image displaying surface, the distance Y being present between the optical axis shared by the most lenses and an edge of the image displaying surface which is farthest from the optical axis shared by the most lenses, wherein a numerical aperture at the image displaying surface side is equal to or larger than 0. 25.