Angular velocity sensor

Abstract

A compact angular velocity sensor, which can improve an S/N (signal/noise) ratio. An angular velocity sensor includes an SOI substrate, four oscillatory masses movably supported to the SOI substrate, and four detection electrodes provided outer side of the oscillatory masses for detecting displacements of the oscillatory masses. The oscillatory masses are arranged point-symmetry with respect to a predetermined point K in a flat plane parallel to the SOI substrate. Each of the four oscillatory masses adjacent each other is oscillated in reverse phase in a circumstantial direction about the predetermined point K along the flat plane. When an angular velocity Ω is generated about the predetermined point K, detection weights of the oscillatory masses are displaced along a direction perpendicular to oscillation direction in the flat plane. Capacitance changes between the detection weights and the detection electrodes are processed in a circuit portion so as to output angular velocity detection signal S1 due to Corioli's force with canceling external acceleration and centrifugal force acted to the detection weights of the oscillatory masses.

Dependencies are inferred from the claim text.