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:
May. 10, 2011
Filed:
Jun. 21, 2007
Hans-juergen Regl, Regensburg, DE;
Gerhard Pfaffinger, Regensburg, DE;
Hans-Juergen Regl, Regensburg, DE;
Gerhard Pfaffinger, Regensburg, DE;
Harman Becker Automotive Systems GmbH, Karlsbad, DE;
Abstract
An electro-acoustic transducer has a membrane comprises a folded or curved sheet of film material. A frame supports the membrane in at least an upper end thereof. A resilient suspension connects the upper ends of the membrane to the frame. A driver system is attached to the frame and the membrane for moving the membrane dependent on an electrical input signal. At least one ferromagnetic element is arranged in the membrane or on one of the surfaces of the membrane at its lower end. At least one magnet provides a magnetic field, the magnet being attached to the frame in a position adjacent the lower end of the membrane. The ferromagnetic element is pulled down by a magnetic force between the element and the magnet establishing a gap therebetween such that tensioning of the membrane is achieved by the magnetic force.