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:
Dec. 05, 2006
Filed:
Jul. 19, 2004
Hideo Torii, Osaka, JP;
Eiji Fujii, Osaka, JP;
Takeshi Kamada, Nara, JP;
Satoru Fujii, Osaka, JP;
Matushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A piezoelectric element includes a first electrode; a piezoelectric layered film composed of a first piezoelectric film formed on the first electrode film and a second piezoelectric film that is formed on the first piezoelectric film and is controlled in crystal orientation thereof by the first piezoelectric film; and a second electrode film formed on the second piezoelectric film. Each of the first and second piezoelectric films is an aggregate of columnar grains grown unidirectionally along a thickness direction of the piezoelectric layered film. A columnar grain of the second piezoelectric film has a larger cross-sectional diameter than a columnar grain of the first piezoelectric film. A ratio l/d of the thickness l of the piezoelectric layered film to the cross-sectional diameter d of the second piezoelectric film is not less than 20 and not more than 60.