Patent ID: 6246527
Filing Date: 2001-06-12
Classification: G02B

Abstract:
An image display apparatus comprising:a reflective image display device adapted to form an observation image for an observer on an image plane by reflecting light rays;a light source constructed and arranged to illuminate the image plane of said reflective image display device from a front side thereof;an image-forming optical system configured to project said image plane as a real image or a virtual image; anda chromatic aberration producing unit constructed and arranged to correct chromatic aberration in the real image or the virtual image, said chromatic aberration producing unit being positioned in an optical path between said light source and said reflective image display device,said image-forming optical system including a prism member,said prism member comprising:an entrance surface through which a bundle of light rays enters said prism member,a reflecting surface configured to reflect the light rays in said prism member, andan exit surface through which a bundle of light rays exits said prism member,wherein said reflecting surface corrects chromatic aberrations due to decentration and has a rotationally asymmetric curved surface configuration.