Patent ID: 6310728
Filing Date: 2001-10-30
Classification: G02B

Abstract:
An image viewing apparatus comprising:a stop for limiting light from an original image; anda viewing optical system for guiding the light from the original image, limited by said stop, to the eye of a viewer, said viewing optical system comprising an optical element of a transparent optical material, wherein said optical element comprises a prism body having an entrance surface into which the light from the original image is incident, a reflecting surface for reflecting the light incident into said entrance surface, and an exit surface from which the light reflected by said reflecting surface is emergent and wherein at least one of said entrance surface, reflecting surface, and exit surface is a curved surface, said curved surface being a rotationally asymmetric, aspherical surface,wherein the following condition is satisfied:3.5<Epy/Lywhere a reference optical axis is defined by a ray emitted from the center of the optical image and passing the center of the pupil of the viewer via said viewing optical system, Ly is a width of the original image in an extending direction of an intersecting line of a plane including the reference optical axis and a plane including the original image, and Epy is a distance from said prism body to an intersecting point on the viewer side, wherein the intersecting point is a point of intersecting of two rays (i) emitted from two edges of the original image in the extending direction of the intersecting line, (ii) passing edges of an aperture of said stop corresponding to the respective edges of the original image, and (iii) passing through said viewing optical system.