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:
Mar. 20, 2007
Filed:
Nov. 24, 2004
Akiko Murata, Osaka, JP;
Eiji Fujii, Osaka, JP;
Hideo Torii, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A piezoelectric element includes a first electrode film; a piezoelectric layered film including a first piezoelectric thin film formed on the first electrode film and a second piezoelectric thin film formed on the first piezoelectric thin film; and a second electrode film formed on the second piezoelectric thin film. Each of the first and second piezoelectric thin films is an aggregate of columnar grains grown unidirectionally along the thickness direction of the piezoelectric layered film. The Pb content of the first piezoelectric thin film is smaller than the Pb content of the second piezoelectric thin film. A columnar grain of the second piezoelectric thin film has a larger average cross-sectional diameter than an average cross-sectional diameter of a columnar grain of the first piezoelectric thin film. A ratio of the thickness of the piezoelectric layered film to the average cross-sectional diameter of the second piezoelectric thin film is not less than 20 and not more than 60.