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:
Oct. 11, 1977
Filed:
Oct. 14, 1975
Hiroshi Iwata, Osaka, JA;
Katsuji Ishikawa, Higashi, JA;
West Electric Co., Ltd., , JA;
Abstract
In exposure means comprising, in combination, two shutter blades which also function as the aperture setting blades, a step-motor for displacing the shutter blades stepwise in response to the driving pulse or pulses, and a driving circuit for the step-motor. Slits are cut through the shutter blades so that the relative displacement between the shutter blades may be optically detected in order to control the stepwise rotation of the step-motor, thereby displacing the shutter blades to define the main aperture stepwise; and when the light from a subject reaches a predetermined level, detecting means causes the step-motor to reverse its rotation, thereby closing the shutter blades. The program-controlled shutter in accordance with the present invention is very simple in construction and is free from any erratic operations.