Optical apparatus and manufacturing method of optical apparatus
AssigneeNikon Corporation
InventorMotohisa MOURI
Life of this patent
Estimating the term…
Abstract
A single lens reflex camera has a finder optical system that observes an image formed on a reticle by an objective lens, and a photometric device that measures light transmitted through the reticle via at least a part of the finder optical system, at a position shifted from an optical axis of the finder optical system. The finder optical system comprises a Fresnel lens surface which transmits light from the objective lens, and the Fresnel lens surface is positioned so that the center of the Fresnel lens surface is shifted in a direction to cross the optical axis of the finder optical system according to a position of the photometric device.
Claims16
An optical apparatus, comprising:
- a finder optical system that observes an image formed on a reticle by an imaging lens;
- and
- a photometric device that measures light transmitted through the reticle via at least a part of the finder optical system, at a position shifted from an optical axis of the finder optical system, wherein
- the finder optical system comprises a Fresnel lens which transmits light from the imaging lens, and
- the Fresnel lens is positioned so that the center of the Fresnel lens is shifted in a direction to cross the optical axis of the finder optical system according to a position of the photometric device.
A manufacturing method of an optical apparatus, comprising the steps of:
- providing a finder optical system that observes an image formed on a reticle by an imaging lens, and a photometric device that measures light transmitted through the reticle via at least a part of the finder optical system, at a position shifted from an optical axis of the finder optical system;
- providing a Fresnel lens which transmits light from the imaging lens in the finder optical system;
- and
- positioning the Fresnel lens so that the center of the Fresnel lens is shifted in a direction to cross the optical axis of the finder optical system according to a position of the photometric device.
Dependencies are inferred from the claim text.