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. 19, 2008
Filed:
Oct. 24, 2003
Yukinori Sasaki, Nishinomiya, JP;
Yukinori Sasaki, Nishinomiya, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A piezoelectric vibrator has a laminated structure where silicon oxide films having substantially the same thickness are disposed at both faces of piezoelectric plate as dielectric films. Using the structure discussed above, because dielectric films are formed at the both faces of the piezoelectric plate a difference of internal stress, which is caused by a difference of stress relaxation in a long term and affects the piezoelectric plate or the dielectric film, becomes small. Therefore, a warp can be considerably small. As a result, a change, which is caused by the warp of the piezoelectric vibrator, in a resonance frequency of the piezoelectric vibrator can be small.