Vibration gyro sensor, control circuit, and electronic apparatus

Abstract

Provided is a vibration gyro sensor including: a vibration element including a piezoelectric element group which has a first side provided with a drive electrode and a detection electrode and a second side opposed to the first side and provided with a common electrode, which vibrates by a drive signal input between the drive electrode and the common electrode and generates an output signal containing a detection signal corresponding to Coriolis force from the detection electrode; a bias section applying a bias voltage to the detection electrode; an oscillation circuit outputting the signal for causing vibration of the vibration element to the drive electrode as the drive signal based on the output signal generated by the detection electrode; and a phase inversion circuit outputting an inversion signal obtained by inverting a phase of the drive signal output from the oscillation circuit to the common electrode.

1 . A vibration gyro sensor, comprising:
 a vibration element including a piezoelectric element group which has a first side provided with a drive electrode and a detection electrode and a second side opposed to the first side and provided with a common electrode, which vibrates by a drive signal input between the drive electrode and the common electrode and generates an output signal containing a detection signal corresponding to Coriolis force from the detection electrode;   bias means applying a bias voltage to the detection electrode;   an oscillation circuit outputting the signal for causing vibration of the vibration element to the drive electrode as the drive signal based on the output signal generated by the detection electrode;   a phase inversion circuit outputting an inversion signal obtained by inverting a phase of the drive signal output from the oscillation circuit to the common electrode;   an addition circuit that adds the first signal obtained from the first detection electrode and the second signal obtained from the second detection electrode,   wherein,
 the detection electrode includes a first detection electrode generating a first signal and a second detection electrode generating a second signal for obtaining the detection signal based on a difference between the first signal and the second signal, 
 the vibration element includes a vibration arm to which the piezoelectric element is mounted, and a base body having a lead electrode group for external connection of the drive electrode and the detection electrodes and which supports the vibration arm, and 
 the vibration element includes an insulation body having a conductive film serving as the common electrode of the piezoelectric element group.