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. 28, 2006
Filed:
Aug. 27, 2003
Dennis Hugh Barnes, Mesa, AZ (US);
Dennis Hugh Barnes, Mesa, AZ (US);
DEI Headquarters, Inc., Vista, CA (US);
Abstract
A loudspeaker motor structure uses variable geometry to change the effective magnetic field acting on the voice coil of the motor structure. A magnet generates the magnetic field, which couples into a front plate, a back plate, and a pole piece. In one loudspeaker, the front plate and the pole piece have notches and slots. Rotating the pole piece relative to the front plate varies the width of the gap between the pole piece and the front plate, and the effective magnetic field in the gap. In another loudspeaker, the pole piece moves up and down in relation to the back plate. This movement varies the magnetic coupling between the pole piece and the back plate and, consequently, the effective magnetic field in the gap between the pole piece and the front plate. Variations in the effective magnetic field in the gap result in variations of the loudspeaker parameters.