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:
Sep. 16, 1980
Filed:
Feb. 15, 1978
Eiichi Tano, Asaka, JP;
Masahiro Kawasaki, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A digital exposure display circuit operates a display element to display exposure information in a camera employing selectable photographing systems including a lens stop priority system, a shutter speed priority system and a manual photographing system. The display circuit includes a first circuit for outputting a voltage proportional to the sum of the brightness of an object to be photographed and a film sensitivity and a second circuit for outputting a voltage proportional to a value obtained by substracting a lens stop value from the output of the first circuit. The display circuit also includes a constant voltage source and a voltage source for providing a voltage corresponding to a manually set shutter speed. A single analog-to-digital converter is provided to generate part of the address of a read only memory. The rest of the read only memory address is provided by a selecting circuit which selects the outputs of the second conduit and the constant voltage source in the lens stop priority system, the output of the first circuit and the voltage source in the shutter speed priority system, and the outputs of the second circuit and the voltage source in the manual photographing system. The selected outputs are supplied to the input of the analog-to-digital circuit. The output of the read only memory is used to energize a display element.