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:
Dec. 22, 1981
Filed:
Jan. 17, 1980
Eiichi Tano, Kamifukuoka, JP;
Koji Suzuki, Asaka, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A combined manual and automatic exposure time control circuit for a camera in which automatic exposure data produced through photometric techniques and manual exposure data set manually are coupled through a switching circuit to a time determination circuit which controls the camera exposure time. The automatic exposure data is produced by a calculation circuit which receives inputs relating to the logarithmic compression values of the object brightness, the film sensitivity, aperture value and exposure setting to thereby digitally calculate the proper exposure time. The output of the calculator is selectively coupled through a switching circuit along with the analog-to-digitally converted manual exposure time setting data to an expansion time determination circuit. The two analog signals are also converted to digital form and selectively coupled through a second switching circuit along with the direct manual exposure data to a display unit with selection being made in accordance with whether a manual or an automatic mode of operation is chosen.