Seiko Epson Corporation

Rutgers, the State University of New Jersey

Mihir S Patel

Masako Tanaka

Yook-Kong Yong

Shigeo Kanna

A quartz crystal resonator includes a quartz crystal resonator element having a main surface including an X axis (electrical axis) and a Z' axis of an inclination rotated at an angle (y) equal to or greater than 36.4 degrees and equal to or smaller than, 40.5 degrees from a Z axis (optical axis) around the X axis, a main vibrating portion vibrating at a predetermined resonance frequency (f) and a supporting portion integrally formed with the main vibrating portion in such a manner as to be formed peripherally to surround the main vibrating portion, and two covers having a thermal expansion coefficient equal to or greater than 6&#xd7;10per degrees centigrade and equal to or smaller than 10&#xd7;10per degrees centigrade and bonded to the supporting portion so as to sandwich the quartz crystal resonator element therebetween.

Quartz crystal resonator

An angular velocity sensor includes a protrusion protruding in a Y'-axis direction and extending in an X-axis direction on a main surface of a rotated Y cut quartz plate, and an excitation electrode and a detection electrode formed on the main surface adjacent to this protrusion. This excitation electrode excites thickness-shear vibration in the X-axis direction on the quartz substrate, exiting vibration on the protrusion. Then, the protrusion is bent and displaced due to Coriolis force acting in a direction orthogonal to the vibration of the protrusion corresponding to a rotation around an Y&#x2032; axis. This displacement at the protrusion is applied to the quartz substrate as stress. The detection electrode detects change of this stress, thereby angular speed added to the angular velocity sensor is detected.

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Highland Park, NJ, United States of America

Mihir S Patel