Patent ID: 8925383
Filing Date: 2015-01-06
Classification: G01C

Abstract:
1. An angular velocity sensor comprising: a vibration body; a first sensor electrode provided on the vibration body for generating an electric signal responsive to an angular velocity applied to the vibration body, the first sensor electrode further generating a first undesired signal; a second sensor electrode provided on the vibration body for generating an electric signal responsive to the angular velocity, the second sensor electrode further generating a second undesired signal; a driver circuit for vibrating the vibration body at a predetermined driving frequency; a processor having an integrator circuit for detecting a signal output from the first sensor electrode; and a cancellation signal output circuit operable to inject a cancellation signal into a point between the first sensor electrode and the processor, the cancellation signal having an amount of an electric signal identical to an amount of a difference between the first undesired signal and the second undesired signal and having a polarity opposite to a polarity of the difference between the first undesired signal and the second undesired signal, wherein the first undesired signal has a phase delayed by 90 degrees from an output signal generated in the first sensor electrode, and the second undesired signal has a phase delayed by 90 degrees from an output signal generated in the second sensor electrode, and wherein the integrator circuit has a time constant which causes the phase delay of 90 degrees of the corresponding first undesired signal to have a further phase shift based on the time constant.