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. 20, 1990
Filed:
Oct. 27, 1989
John P Gaewsky, Reading, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
A shutter mechanism actuated by a plunger type solenoid in an exposure control system for a reflex camera is provided with a solenoid drive control for reducing the subject-distracting mechanical noise that is normally generated when the solenoid plunger is driven into its fully retracted position in order to close shutter blades forming a portion of the shutter mechanism, immediately prior to an exposure interval. The solenoid drive control comprises a microcontroller and a blade encoder to indicate the degree of blade closure. Blade closure signals are routed to the microcontroller that, in response thereto, causes a reduction in the amount of solenoid actuating current delivered to the solenoid to thereby reduce the amount of solenoid drive and therefore the amount of mechanical noise that is generated when the solenoid plunger is driven into the fully retracted position.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile