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. 09, 1985
Filed:
Oct. 25, 1982
Tomio Kurosu, Iwatsuki, JP;
Yukio Yoshikawa, Tokyo, JP;
Copal Company Limited, Tokyo, JP;
Abstract
The device for detecting the time of termination of the opening operation of shutter blades of an electromagnetic programming shutter comprises an induction coil secured to either one of a member coupled with the operation of the shutter blades and a base plate, a permanent magnet secured to the other one of the member and the base plate in facing relationship to the induction coil, and a detecting circuit for detecting the vanishing of the electric current induced in the induction coil resulting from the termination of the relative movement between the induction coil and the permanent magnet at the time of termination of the opening operation of the shutter blades after the shutter blades have initiated the opening operation from the closed positions for causing the relative movement between the induction coil and the permanent magnet so as to generate the induced current in the induction coil, thereby permitting the time of termination of the opening operation of the shutter blades to be detected. Since a programming shutter may initiate the closing operation of the shutter blades even though they have not been fully opened so as to serve as a diaphragm stop in order to obtain proper exposure, the time of termination of the opening operation of the shutter blades must be exactly detected in order to accurately actuate a stroboflash device. The present invention can detect very accurately the required time for the operation of the stroboflash device in the very simple and inexpensive manner without requiring undue loss of energy.