Angular velocity sensor and electronic device
First Claim
1. An angular velocity sensor, comprising:
- a base portion;
three arm portions that extend as one piece from the base portion to an approximately same direction;
a piezoelectric film formed on one surface of each of the arm portions;
drive electrodes for excitation formed on the piezoelectric films of at least a first arm portion and a second arm portion, said first and second arm portions being positioned on outer sides, among the three arm portions; and
detection electrodes for angular velocity detection formed on the piezoelectric film of at least a centrally-positioned arm portion, among the three arm portions, wherein;
among the three arm portions, the two arm portions that are positioned on outer sides are excited in phase with respect to each other, and the centrally-positioned arm portion is excited in opposite phase with respect to the two arm portions that are positioned on outer sides,the drive electrodes excite the arm portions in a first direction vertical to surfaces on which the piezoelectric films are formed, andthe detection electrodes detect a vibration in a second direction parallel to the surfaces on which the piezoelectric films of the arm portions are formed.
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Accused Products
Abstract
An angular velocity sensor includes a base portion, three arm portions that extend as one piece from the base portion to an approximately same direction, a piezoelectric film formed on one surface of each of the arm portions, drive electrodes for excitation formed on the piezoelectric films of at least two outer arm portions, and detection electrodes for angular velocity detection formed on the piezoelectric film of at least a center arm portion. Among the three arm portions, the two outer arm portions are excited in phase, and the center arm portion is excited in opposite phase with the two outer arm portions. The drive electrodes excite the arm portions in a first direction vertical to surfaces on which the piezoelectric films are formed. The detection electrodes detect a vibration in a second direction parallel to the surfaces on which the piezoelectric films of the arm portions are formed.
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Citations
16 Claims
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1. An angular velocity sensor, comprising:
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a base portion; three arm portions that extend as one piece from the base portion to an approximately same direction; a piezoelectric film formed on one surface of each of the arm portions; drive electrodes for excitation formed on the piezoelectric films of at least a first arm portion and a second arm portion, said first and second arm portions being positioned on outer sides, among the three arm portions; and detection electrodes for angular velocity detection formed on the piezoelectric film of at least a centrally-positioned arm portion, among the three arm portions, wherein; among the three arm portions, the two arm portions that are positioned on outer sides are excited in phase with respect to each other, and the centrally-positioned arm portion is excited in opposite phase with respect to the two arm portions that are positioned on outer sides, the drive electrodes excite the arm portions in a first direction vertical to surfaces on which the piezoelectric films are formed, and the detection electrodes detect a vibration in a second direction parallel to the surfaces on which the piezoelectric films of the arm portions are formed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An electronic device, comprising:
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a main body; and an angular velocity sensor, wherein the angular velocity sensor includes; a first arm portion, including a first drive electrode, that is excited in a first direction by piezoelectric drive; a second arm portion, including a second drive electrode, arranged to extend in a length direction of the first arm portion, and being excited by piezoelectric drive in the first direction in phase with the first arm portion; a third arm portion, including detection electrodes that detect Coriolis force acted in a second direction perpendicular to the first direction and the length direction, arranged to extend in the length direction between the first arm portion and the second arm portion, and vibrating in opposite phase with vibrations of the first and second arm portions; and a base portion that supports the first, second, and third arm portions, and wherein the angular velocity sensor is disposed within the main body, and the first direction in perpendicular to a plane extending through a central axis of each of said arm portions.
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Specification