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. 08, 2002
Filed:
Oct. 27, 2000
Hitoshi Oka, Tokyo, JP;
Masakazu Hirose, Tokyo, JP;
Yasuo Watanabe, Tokyo, JP;
Junji Terauchi, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A piezoelectric ceramic material comprising a bismuth layer compound containing M , Bi, Ti and O wherein M is selected from Sr, Ba and Ca, and containing M Bi Ti O type crystals, wherein M , is represented by Sr Ba Ca wherein x+y+z=1, utilizes thickness shear vibration when 0≦x≦ 1, 0≦y≦0.9, and 0≦z≦1, and thickness extensional vibration when 0≦x<0.9, 0≦y≦0.9, and 0≦z<1. Also provided is a piezoelectric ceramic material comprising a bismuth layer compound containing Ca, Bi, Ti, Ln and 0 wherein Ln is a lanthanoid, and containing CaBi Ti O type crystals, wherein the atomic ratio Ln/(Ln+Ca) is in the range: 0<Ln/(Ln+Ca)<0.5. These piezoelectric ceramic materials are free of lead, and have a high Curie point and improved piezoelectric characteristics.