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. 12, 2002
Filed:
Dec. 06, 1999
Sakuzo Denda, Nagano, JP;
Toshiiku Miyazaki, Omiya, JP;
FPS, Inc., Tokyo, JP;
Abstract
Permanent magnets m m and m each of which is formed in a flat and rectangular shape are disposed on a yoke with the magnetic pole surfaces facing upwardly so that the magnetic pole surfaces whose polarities are different are disposed alternately. A vibrating diaphragm is disposed on the top surface of the yoke so as to be in parallel with the magnetic pole surfaces of the permanent magnets. Pairs of coils L L and L which are wound in a swirled shape and are disposed at the top and rear surfaces of the vibrating diaphragm are disposed on the vibrating diaphragm so as to correspond to the permanent magnets m and m respectively. Each of the pairs of coils L L and L is wound in a swirled shape so as to be substantially analogous with the external edge of the magnetic pole surface of each of the permanent magnets m m and m The internal periphery of each coil is situated at an area which is outside a position corresponding to the external edge of the magnetic pole surface, and the external peripheral portions of the coils do not overlap with each other. As a result, the pairs of coils L L and L link to only the magnetic fields whose orientations are along the surface of the vibrating diaphragm.