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:
Jan. 16, 1990
Filed:
May. 12, 1988
Nihon Dempa Kogyo Co., Ltd., Tokyo, JP;
Abstract
At least one pair of exciting electrodes are formed opposite to each other on two major surfaces of a piezoelectric plate. Electrodes and that portion of the piezoelectric plate which is held between at least the exciting electrodes, form a resonance region where thickness-shear vibrations of plural modes are excited. A waveguide path having a cut-off frequency higher than the frequency of at least one desired vibration excited in the resonance region, but lower than the frequencies of the thickness-shear vibrations, whose damping is desired, and excited in the resonance region, is formed and extends in a direction substantially the same as the propagating direction of the thickness-shear vibration whose damping is desired, and has a width 0.5 times or more the width of the resonance region. A vibration absorbent is arranged in the waveguide path.