Patent Number: 6,310,736

Title: Image-forming optical system and viewing optical system

Abstract: A viewing optical system and image-forming optical system in which an intermediate image is formed once and two decentered prisms, i.e. first and second prisms, are arranged to correct each other's decentration aberrations, thereby attaining a wide viewing field angle and a short focal length. The second prism is placed closer to the object side than the first prism and has three optical surfaces, of which a first surface is an entrance surface also serving as a reflecting surface, a second surface is a reflecting surface, and a third surface is an exit surface. At least one of the first and second surfaces has a rotationally asymmetric surface configuration that gives a power to a light beam and corrects aberrations due to decentration. The first prism has a reflecting surface, an entrance surface, and an exit surface. The reflecting surface has a rotationally asymmetric surface configuration that gives a power to a light beam and corrects aberrations due to decentration. An intermediate image surface is formed between the first surface of the second prism and the exit surface of the first prism.

Inventors: Togino; Takayoshi (Hachioji, JP)

Assignee: Olympus Optical Co., Ltd.

International Classification: G02B 27/01 (20060101); G02B 005/04 (); G02B 027/14 ()

Expiration Date: 10/30/2018