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:
Sep. 15, 1981
Filed:
May. 10, 1979
Applicant:
Inventors:
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01F / ; H04R / ;
U.S. Cl.
CPC ...
1791 / ; 29607 ; 335231 ;
Abstract
A speaker comprises a voice coil placed in an air gap between a center pole and a plate wherein a specific ferromagnetic material obtained by forming fine crystalline grains is used on at least one of the surfaces of the center pole and the plate which respectively face the voice coil, thereby providing a speaker having low distortion.