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:
Nov. 22, 1988
Filed:
Dec. 22, 1987
Copal Company Limited, Tokyo, JP;
Abstract
A lens shutter using an electrostrictive strain element as a driving source, arranging a shutter blades opening and closing lever and the electrostrictive strain element driving the opening and closing lever so that inertia forces acting on the opening and closing lever through engagement with the electrostrictive strain element and acting on the electrostrictive strain element through engagement with the opening and closing lever are counterbalanced by each other, in order to eliminate variations of exposure caused by various positions of a camera. The basic portion of the electrostrictive strain element is secured to a retaining member supported rotatably on a shutter base plate and the retaining member may well be biased by a spring to increase the inertia force of the electrostrictive strain element. Thereby, even if a shock is applied to the shutter from the outside, it does not occur that the shutter blades are inadvertently opened and closed. The rotation of the retaining member to rotate the opening and closing lever in a direction to open the shutter blades through the electrostrictive strain element is prevented by an eccentric pin.