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:
Feb. 21, 1984
Filed:
Sep. 11, 1981
Masafumi Yamasaki, Tokyo, JP;
Muneaki Yoshida, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
Disclosed is a single lens reflex camera of the mean metering type having a first photodiode provided between a mirror and a film and a second photodiode provided in a finder system in which before the shutter release a shutter time is calculated on the basis of an output signal of the second photodiode and is displayed in the finder, and when the shutter release starts and the mirror rises and the shutter time is determined by an output signal from the first photodiode for receiving the reflected light from a front shutter curtain and the film. In the camera, a central portion of the mirror is translucent. A submirror is provided behind the translucent portion, which causes the first photodiode to receive the light from only the central portion of a frame before the shutter release. Further, the camera has a first operating circuit for obtaining a difference between the outputs from the first and second photodiodes before the shutter release and a second operating circuit for adding the result of the operation by the first operating circuit to the output from the first photodiode during the shutter release, whereby a partial metering for controlling a shutter time during the shutter release in accordance with the result of the operation by the second operating circuit is realized.