Patent ID: 7673512

Claim:
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, 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.