Patent ID: 6362561
Filing Date: 2002-03-26
Classification: H03H

Abstract:
A piezoelectric vibration device comprising:a piezoelectric element including first and second longitudinal edges, first and second longitudinally opposed ends, top and bottom surfaces provided between the first and second ends such that the top and bottom surface oppose each other, and beveled surfaces disposed at a vicinity of the first and second ends such that the thickness of the piezoelectric element gradually decreases towards the first and second ends, respectively; and first and second vibration electrodes disposed on the top surface and the bottom surface of the piezoelectric element, respectively, the first and second vibration electrodes located substantially at a middle portion of the piezoelectric element so as to opposed each other with the piezoelectric element disposed therebetween to define opposing portions which constitute a vibrator, the first and second vibration electrodes extend over substantially the entire width of the piezoelectric element from the first longitudinal edge to the second longitudinal edge; wherein a roughness of the beveled surfaces is greater than a roughness of a surface of the piezoelectric element located at the opposing portions and beneath the first and second vibration electrodes; and the piezoelectric element and first and second vibration electrodes are arranged to generate a thickness shear mode and to suppress spurious responses due to a longitudinal direction mode and a contour mode.