Patent ID: 7107843

Claim:
An angular velocity sensor comprising: a tuning fork vibrator including at least two arms, and a base to connect the at least two arms; a drive unit which is provided on a main surface of an arm of the at least two arms of the tuning fork vibrator so as to excite the tuning fork vibrator in one of an X direction and a Z direction of the tuning fork vibrator; a detection unit which is provided on the main surface of the arm of the at least two arms of the tuning fork vibrator so as to detect bending of the tuning fork vibrator vibrating in the Z direction in response to incoming angular velocity; a first drive circuit which makes the drive unit excite the tuning fork vibrator in the X direction; a detection circuit which includes an amplifier for amplifying a signal from the detection unit and producing an angular velocity signal; a second drive circuit which applies a drive signal to the drive unit so as to make the drive unit excite the tuning fork vibrator in the Z direction; and a self-diagnostic circuit which compares an output of the amplifier with a reference value when the second drive circuit applies the drive signal to the drive unit, and which determines to be abnormal when a prescribed value cannot be obtained.