Focusing optical system for single-lens reflex
AssigneeOlympus Optical Co., Ltd.
InventorTadashi Kimura
Life of this patent
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Abstract
A focusing optical system for single-lens reflex cameras comprising an auxiliary lens arranged in the vicinity of the focusing surface of a focusing glass and a detector element arranged in the vicinity of a penta-prism, and so adapted as to detect the focusing point by transferring a portion of the light from an object to said detector element.
Claims7
A focusing optical system for single-lens reflex which includes a viewfinder having an optical axis, said optical system comprising a photographing lens, a focusing glass arranged at the position at which an object image is formed by said photographing lens, a penta-prism arranged at the back of said focusing glass, image detecting means, arranged on said optical axis in contact with said penta-prism, for detecting light intensity of paraxial rays for enabling automatic focusing of said photographing lens and an auxiliary optical means for transferring a portion of the image of the object image formed on said focusing glass to said image detecting means.
Dependencies are inferred from the claim text.