The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 1984
Filed:
Jan. 30, 1981
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A compensator system for diaphragm control in a single-lens reflex camera of interchangeable type having an exposure control circuit responsive to the position of a lever that is operatively coupled to the diaphragm according to a preset position of a diaphragm preset ring. The exposure control circuit is regulated for compensating any errors in illumination intensity in a film plane provided by individual interchangeable lenses and errors in illumination intensity provided by photometric operation through respective lenses mounted on a camera in relation with a specific position of a light receiving element contained in a photometric circuit. A diaphragm preset ring has on the periphery thereof an indication for the automatic diaphragm control at a predetermined angular distance from an indication for the fully closed diaphragm value of an associated lens. An arithmetic factor is provided for exposure control comprising an electric adjustment factor such as a resistance value or binary signal that is selected by the lever when the diaphragm preset ring has been rotated to the automatic diaphragm control position. A signal is provided for detecting a fully closed diaphragm and a fully opened diaphragm. Compensation is provided for a deviation from the signal representing the fully opened diaphragm value not represented by any of the specific series of a multiple of a first displacement provided by a diaphragm blade actuator system.