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:
May. 03, 1977
Filed:
Sep. 11, 1975
Katsuhiko Miyata, Saitama, JA;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JA;
Abstract
A through the lens (TTL) photometric function is provided by apparatus built into a viewfinder system for a single lens reflex (SLR) camera. As to the viewfinder function, an optical path is defined between the SLR focusing screen and a viewfinder eyepiece. A first prism, forming part of the optical path, has a plurality of faces, two of which serve to internally reflect light entering the prism so that the light emerging from the prism has been twice reflected. As to the photometric function, at least one separate optical path is defined for light emerging from the first prism at a peripheral position outside the finder field. In each separate optical path there is a second prism and a light receiving element with the second prism being arranged between the first prism and the light receiving element.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile