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. 09, 1982
Filed:
Dec. 27, 1978
Applicant:
Inventors:
Ichiro Horikoshi, Tokyo, JP;
Shigeo Mori, Tokyo, JP;
Fumikazu Murakami, Tokyo, JP;
Yoshiaki Hara, Tokyo, JP;
Susumu Fujita, Tokyo, JP;
Assignee:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
1791 / ;
Abstract
An electro-magnetic type electric acoustic transducer comprising an exciting portion consisting of a back plate mounting a permanent magnet and a magnetic core winding an exciting coil therearound, a vibrating plate arranged opposite to said exciting portion leaving a certain space, and a vibrating plate supporting member which supports the periphery of said vibrating plate, characterized in that the resonance frequency of the vibrating plate is reduced while maintaining sound pressure by providing an air hole at a part of said plate or said vibrating plate supporting member.