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. 11, 1979
Filed:
Mar. 31, 1978
Nobuaki Date, Kawasaki, JP;
Hiroshi Aizawa, Kawasaki, JP;
Masanori Uchidoi, Yokohama, JP;
Masami Shimizu, Tokyo, JP;
Yoshiyuki Takishima, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In the camera disclosed, an electromagnetic actuator is responsive to a timing pulse of short duration from an exposure control circuit for controlling the closing movement of a shutter. A permanent magnet may accidently be left latched and hold the rear curtain in cocked position after the timing pulse because of possible damage to an electromagnetic control circuit as a result of a battery short circuit. This may cause the film to fog during subsequent winding or rewinding. To prevent this, an indicator produces a visible indication either in the field of view of the camera finder or, in the case of remote shutter operation, outside the camera housing, that the rear curtain must be manually unlatched.