Patent ID: 6464361
Filing Date: 2002-10-15
Classification: G02B

Abstract:
An image display apparatus having a three-dimensionally decentered optical path, said image display apparatus comprising:an image display device for forming an image for observation on an image display area; and a viewing optical system for leading the image formed by said image display device to a pupil corresponding to a position where an eyeball of an observer is to be placed; said image display device being a single image display device having a plurality of pixels juxtaposed on a single substrate; wherein each pixel located at least in a central portion of said single image display device is arranged to emit an image light beam at such an exit angle that the light beam can be led to left and right eyes of the observer; said viewing optical system including at least: a left ocular part for leading the light beam to the left eye of the observer; a right ocular part for leading the light beam to the right eye of the observer; and an optical path distributing part for distributing the image light beam emitted from said image display device at said exit angle to said left ocular part and said right ocular part; said left ocular part having at least two reflecting surfaces, wherein at least one of said at least two reflecting surfaces is formed from a rotationally asymmetric curved reflecting surface having a function of correcting decentration aberrations; said right ocular part having at least two reflecting surfaces, wherein at least one of said at least two reflecting surfaces is formed from a rotationally asymmetric curved reflecting surface having a function of correcting decentration aberrations; wherein said left ocular part and said right ocular part are arranged so that a plane of a decentered optical path of an axial principal ray formed by said at least two reflecting surfaces of said left ocular part (said plane being a YZ-plane, which is a vertical direction of the observer) and a plane of a decentered optical path of an axial principal ray formed by said at least two reflecting surfaces of said right ocular part (said plane being a YZ-plane, which is a vertical direction of the observer) are approximately parallel to each other (YZ-plane); and wherein said optical path distributing part has optical surfaces arranged in bilaterally rotational symmetry to form left and right optical paths that are not in plane symmetry with each other but in 180-degree rotational symmetry with respect to only a normal line passing through a center of said image display device, and said optical path distributing part has at least two pairs of reflecting surfaces as said optical surfaces for the left and right optical paths.