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. 11, 1984
Filed:
Nov. 09, 1981
Applicant:
Inventor:
Akio Kumada, Kokubunji, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
310345 ; 310348 ; 368255 ;
Abstract
In a transducer including at least a piezoelectric ceramic plate which has curved surfaces, electrodes which are formed on both the main surfaces of the piezoelectric ceramic plate, a frame which holds the piezoelectric ceramic plate, and means for applying an electric signal to the electrodes; this invention is characterized in that the holding frame is made of an organic high-polymer resin. Since the piezoelectric ceramic plate has the curved surfaces and the holding frame is made of the organic high-polymer resin, the transducer is suitable as a loudspeaker for audio use having a wide frequency band.