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. 10, 2000
Filed:
Mar. 27, 1998
Kazushi Tachimoto, Chiba, JP;
Mahoko Takada, Chiba, JP;
Kenji Horino, Akita, JP;
Kazuo Miyabe, Chiba, JP;
Hitoshi Oka, Chiba, JP;
TDK Corporation, Tokyo, JP;
Abstract
The object of the present invention is to realize the piezoelectric ceramics which, even when used as high frequency elements utilizing third harmonics wave of thickness longitudinal vibration, are small in temperature coefficient of resonant frequency and high in mechanical Q value and easy to correspond to the trend toward miniaturization and low voltage driving. When the piezoelectric ceramics with lead titanate as its main component are manufactured in order to achieve this object, it was decided that the piezoelectric ceramics be manufactured by the manufacturing method, wherein a heat treatment is performed between a firing process and a polarization process in the atmosphere of oxygen partial pressure less than the oxygen partial pressure of the atmospheric pressure at temperatures more than 500.degree. C. and not more than the firing temperatures.