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. 10, 1998
Filed:
Feb. 14, 1997
Sony Corporation, Tokyo, JP;
Abstract
A speaker apparatus includes a yoke formed of a magnetic material and having a flange portion and a center pole protruded integrally forwards from a mid portion of the flange portion, and a ring-shaped driving magnet into which the center pole is inserted. The speaker apparatus also includes a top plate mounted on the driving magnet. The top plate is formed of a magnetic material and the center pole is inserted through the top plate. The top plate defines a magnetic gap together with the center pole. The speaker apparatus further includes a voice coil mounted on a bobbin secured to a diaphragm in the magnetic gap, and a canceling magnet arranged on the outer periphery of and spaced from the driving magnet at a pre-set spacing for covering the driving magnet. The canceling magnet cancels the magnetic flux leaking to outside a magnetic circuit including the driving magnet.