Patent ID: 6240780
Filing Date: 2001-06-05
Classification: G01C

Abstract:
An angular velocity sensor comprising:a board;a first vibrator supported on the board through first supporting beams and arranged so as to be vibrated in the direction of a first axis;a second vibrator supported on the first vibrator through second supporting beams and arranged so as to be vibrated in the direction of the first axis by the first vibrator and in the direction of a second axis at a right angle to the direction of the first axis when an angular velocity is applied to the second vibrator around a third axis at right angles to the first and second axes;a vibration generating means to cause the first vibrator to vibrate in the direction of the first axis;a displacement detecting means to detect a displacement of the second vibrator in the direction of the second axis when the angular velocity is applied around the third axis and when the vibration generating means causes the first vibrator to vibrate in the direction of the first axis; anda frequency adjustment means for adjusting a vibrating side resonance frequency when the first vibrator is vibrated in the direction of the first axis by the vibration generating means and adjusting the detecting side resonance frequency when the second vibrator is vibrated in the direction of the second axis by an angular velocity applied around the third axis, the frequency adjustment means including a vibrating side additional electrode formed on an end surface of the first vibrator and a fixed side additional electrode facing the vibrating side additional electrode and formed on a side of the board, the frequency adjustment means applying in the first direction an electrostatic attraction force caused between the vibrating side additional electrode and the fixed side additional electrode.