Focus detecting optical system
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorTakayuki Sensui
Life of this patent
Estimating the term…
Abstract
A focus detecting optical system includes a reduction lens having a positive refractive power that is located between an objective lens and an image taking plane on which a primary image of a subject is formed by the objective lens, a separation plane mirror for separating a light passed through the reduction lens from an optical path toward the image taking plane, a pair of separator lenses for re-forming an image formed through the reduction lens and the separation plane mirror into a pair of secondary images, and a pair of image sensors for capturing the secondary images. The optical axis of the reduction lens is coaxial with the optical axis of the objective lens.
Claims4
A focus detecting optical system comprising:
- a reduction lens having a positive refractive power, said reduction lens being located between an objective lens and an image taking plane, a primary image of a subject being formed by said objective lens on the image taking plane, the optical axis of said reduction lens being coaxial with the optical axis of said objective lens;
- a separation plane mirror that separates light passed through said reduction lens from an optical path extending toward said image taking plane;
- a pair of separator lenses that re-form an image formed through said reduction lens and said separation plane mirror into a pair of secondary images;
- a pair of image sensors that capture said secondary images;
- wherein said reduction lens has a refractive power to make an exit pupil of said objective lens be optically conjugate with entrance pupils of said separator lenses.
Dependencies are inferred from the claim text.