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:
Jul. 05, 1994
Filed:
Jul. 06, 1992
Nobuaki Date, Kanagawa, JP;
Shohei Takeda, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An exposure device with a shutter operating in such a manner that the size of aperture opening defined by the shutter blades first increases from zero and then starts to decrease in predetermined timing, comprises a mechanism for opening the shutter with the help of an electric motor, while charging a spring as the drive source for closing movement of the shutter, an electromagnet arranged upon current supply to change the driving of the shutter from the opening mechanism to the spring, and a control circuit for controlling the operation of the shutter in such a manner that when taking one picture, the shutter blades reciprocate two times continuously to recycle substantially twice the exposure operation, as the operation of each of the motor and the electromagnet is recycled twice.