Patent ID: 7262919
Filing Date: 2007-08-28
Classification: G02B

Abstract:
1. An optical apparatus comprising: a device for displaying an image; and an ocular optical system for projecting an image formed by said device for displaying an image and for leading the image to an observer's eyeball; said ocular optical system comprising first, second and third surfaces, in which a space defined by said first, second and third surfaces is filled with a medium having a refractive index larger than 1; said first, second and third surfaces including, in order from an observer's eyeball side toward said device for displaying an image, a first surface serving as both a refracting surface and an internally reflecting surface, a second surface serving as a reflecting surface of positive power which faces said first surface and is decentered or tilted with respect to an observer's visual axis, and a third surface serving as a refracting surface closest to said device for displaying an image, at least two of said at least three surfaces having a finite curvature radius; wherein any one of said first, second and third surfaces is a decentered aspherical surface; wherein any one of said first, second and third surfaces is an anamorphic surface; wherein said optical apparatus satisfies the following condition in a case where a vertical plane containing said observer's visual axis is defined as a YZ-plane, and a horizontal plane perpendicular to the YZ-plane is defined as an XZ-plane: where R y2 is a curvature radius of said second surface in the YZ-plane, and R x2 is a curvature radius of said second surface in the XZ-plane.