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, 1984
Filed:
Dec. 28, 1982
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An electromagnetically controlled shutter with a latch member held in an active position by an electromagnet containing a permanent magnet and operating upon de-magnetization of the electromagnet to release the shutter. To prevent reduction of the attractive force by the adhesion of dust, oil or the like to the attracting surface of the electromagnet and also to improve the ramping characteristics of the shutter, an arrangement is provided such that when the electromagnet is de-energized, the shutter latching member is pulled away from the electromagnet by a breakaway spring. Then the breakaway spring impels the shutter to run down in an early stage, and loses its impelling force. Soon after that, the shutter latching member is returned to the attracted position by an attracting spring.