Patent Number: 6,297,909

Title: Focus detecting optical system

Abstract: A focus detecting optical system includes a reduction lens having apositive refractive power that is located between an objective lens and animage taking plane on which a primary image of a subject is formed by theobjective lens, a separation plane mirror for separating a light passedthrough the reduction lens from an optical path toward the image takingplane, a pair of separator lenses for re-forming an image formed throughthe reduction lens and the separation plane mirror into a pair ofsecondary images, and a pair of image sensors for capturing the secondaryimages. The optical axis of the reduction lens is coaxial with the opticalaxis of the objective lens.

Inventors: Sensui; Takayuki (Tokyo, JP)

Assignee:

International Classification:

Expiration Date: 10/02/2013