Optical system having reflecting surface of non-rotationally symmetric surface configuration

摘要

An optical system for use, for example, in a head-mounted image display apparatus, which provides an observation image that is clear and has minimal distortion even at a wide field angle. The head- mounted image display apparatus has an image display device (6), and an optical system (9) that leads an image formed by the image display device (6) to an observer's eyeball position (1), without forming an intermediate image, so that the image can be observed as a virtual image. The optical system (9) includes a reflecting surface (4) performing only one reflection, and one or two transmitting surfaces (3). The space between the reflecting surface (4) and the transmitting surfaces (3) is filled with a medium having a refractive index larger than 1. At least the reflecting surface (4) is a non-rotationally symmetric surface configuration having no axis of rotational symmetry in nor out of the surface.