Patent ID: 8950874
Filing Date: 2015-02-10
Classification: G02B,G03B

Abstract:
1. A projection optical system for use in an image display apparatus having an illumination optical system configured to apply light emitted from a light source, and an image display device configured to receive the light applied from the illumination optical system to form a projection image, the projection optical system comprising: a projector lens composed of a plurality of lenses; a first mirror; and a second mirror formed of a concave mirror, the projection optical system being configured to project the projection image formed by the image display device onto a projection surface, wherein a projection luminous flux passing through the projector lens to be incident on the first mirror is a luminous flux exhibiting divergence, wherein the projection luminous flux reflected off the second mirror after having reflected off the first mirror is converged once, and the once converged projection luminous flux is then projected onto the projection surface, and wherein a lens surface of a lens located closest to the first mirror among the lenses of the projector lens is convex; wherein a position at which the projection luminous flux reflected off the second mirror is converged is closer to the first mirror than to the second mirror.