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. 15, 2005
Filed:
Apr. 08, 2003
Masakazu Yamauchi, Toyama-ken, JP;
Tetsuo Takeshima, Toyama, JP;
Manabu Sumita, Toyama, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A piezoelectric electro-acoustic transducer includes a piezoelectric vibration plate having a plurality of piezoelectric ceramic layers laminated to each other with an internal electrode being interposed between the ceramic layers, and main surface electrodes provided on the front and back surfaces thereof, whereby area bending vibration is produced by applying an AC signal between the main surface electrodes and the internal electrode, respectively, a resin film having a size that is greater than the piezoelectric vibration plate and having the piezoelectric vibration plate bonded substantially to the central portion of the surface thereof, and a casing which accommodates the piezoelectric vibration plate and the resin film. The piezoelectric vibration plate has an area of about 40% to about 70% of that of the resin film. The inner peripheral surface of the case is provided with a supporting portion having a frame shape that is larger than that of the piezoelectric vibration plate, and the outer peripheral portion of the resin film having no piezoelectric vibration plate bonded thereto is supported by the supporting portion of the case.