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:
Oct. 06, 2015
Filed:
Aug. 26, 2010
Tetsuro Sata, Kirishima, JP;
Tetsuro Sata, Kirishima, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
A center of a multi-layer piezoelectric element is an active region and deforms to a greater degree than ends thereof which is an inactive region during driving operation, and is therefore more susceptible to stress concentration and crack development. To address this problem, a multi-layer piezoelectric element includes a columnar stacked body in which piezoelectric layers and internal electrode layers are alternately laminated, and a pair of external electrodes configured to bond to side faces of the columnar stacked body, wherein a side face of the columnar stacked body is configured so that a surface roughness of a center of the side face in a stacked direction of the columnar stacked body is greater than those of ends of the side face in the stacked direction of the columnar stacked body. This makes it possible to relax the stress exerted on the side face of the columnar stacked body, and thereby enhance the durability of the multi-layer piezoelectric element.