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. 05, 2000
Filed:
Jul. 16, 1999
Bodo Mielke, Wolfenbuettel, DE;
Rollei Fototechnic GmbH, Braunschweig, DE;
Abstract
An electromagnetic drive for a focal-plane shutter of a camera having two light-excluding shutter curtains, each of the two shutter curtains being having its own electric drive motor, which is a linear motor constructed from permanent magnets and electromagnetic coils. The linear motor has at least two mutually aligned permanent magnets. The opposite pole faces of the magnets have the same polarity. A soft-magnetic disk is disposed between the permanent magnets. A soft-iron casing encloses the magnets and the soft-magnetic disk with an annular gap therebetween. A coil former is displaceably mounted in the annular gap such that it can exert an operating stroke between two stops. The coil former has a drive element for transferring the axial displacement of the coil former to the assigned shutter curtain.