ANGULAR VELOCITY SENSOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an angular velocity sensor which is capable of stabilizing the operation while improving element sensitivity with a voltage value of a driving signal equal to or higher than a prescribed voltage.SOLUTION: A piezoelectric layer 9 shows such hysteresis characteristics that, when a voltage value of a driving signal applied to four vibration excitation electrodes 11 is equal to or higher than a prescribed voltage, a gain being a ratio of an output voltage of a displacement detection part to the voltage value becomes a maximum value at a first frequency by continuously increasing the frequency of the driving signal and is reduced by furthermore increasing the frequency and then becomes the maximum value at a second resonance frequency lower than the first frequency by decreasing the frequency of the driving signal. Setting is performed so that the driving signal which has a frequency lower than and close to the second resonance frequency and has the voltage value of the prescribed voltage or higher is applied to the four vibration excitation electrodes 11.