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:
Dec. 11, 1979
Filed:
Oct. 02, 1978
Edwin K Shenk, Westford, MA (US);
Shirley Y Tam, Arlington, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
The operational range of an adjustable focus lens is subdivided into a plurality of focus zones, of finite size, by a lens control system that produces a plurality of discrete signals representative of said focus zones, said control system utilizing bidirectional drive means to position the movable element of said lens to one of said focus zones from any position within said operational range in order to focus an image of a remote object at an image plane. The present invention equalizes and minimizes the focusing error introduced into said lens control system resulting from the use of such focus zones with bidirectional drive means, by utilizing electrodynamic braking to arrest lens movement within a predetermined portion of a focus zone, once said lens has entered said zone to focus an image of said remote object at said image plane.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile