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:
Aug. 07, 1979
Filed:
Jul. 05, 1978
Applicant:
Inventor:
Nobutaka Ohnuki, Yokohama, JP;
Assignee:
Hitachi, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ; H04R / ;
U.S. Cl.
CPC ...
1791 / ; 1791 / ; 181170 ; 181174 ;
Abstract
An electro-acoustic transducer having a flat sound radiating plane is disclosed, in which a voice coil bobbin having a voice coil wound around an outer circumference thereof is inserted in an air gap defined by an inner pole piece and an outer pole piece and dome-shaped diaphragm is inserted in the voice coil bobbin to define a front chamber surrounded by curved surfaces of an outer surface of the diaphragm and an inner surface of the voice coil bobbin, and foamed synthetic resin is filled in the front chamber.