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:
Feb. 03, 2004
Filed:
Jul. 27, 2001
TDK Corporation, Tokyo, JP;
Abstract
The invention provides a piezoelectric ceramic material comprising a Bi TiNbO crystal and/or an MBi Nb O crystal which are each a bismuth layer compound, where M represents at least one element selected from Sr, Ba and Ca. The ceramic material contains Bi, Ti, M and Nb as main component elements. The molar ratio as oxides of the main component elements is given by (Bi M ) (Nb Ti provided that 0<x, y≦0.8 and 0.95≦z≦1.05. When the molar ratio of Ba/(M+Bi) is given by x /3 and the molar ratio of Ca/(M+Bi) is given by x /3, it is required that 0≦x ≦0.5 and 0≦x <0.4. This piezoelectric ceramic material, free from any lead whatsoever, has a sufficiently high Curie point, and exhibits ever more improved piezoelectric properties.