Patent ID: 8497672

Claim:
An acceleration sensor comprising: a substrate; an anchor portion formed on the substrate; a support beam having one end connected to the anchor portion and extending spaced apart from the substrate; a proof mass being connected to the other end of the support beam and spaced apart from the substrate; first and second piezoelectric bending resonators, each having one end connected to the anchor portion and the other end connected to the proof mass or the support beam thereby extending to both sides of the support beam, and each comprising a first electrode, a first piezoelectric film and a second electrode being stacked in a direction perpendicular to the first piezoelectric film to perform bending resonance motion in the direction; a first comparison unit configured to output a first value, the first value is a difference of a resonance frequency between the first and second piezoelectric bending resonators; and a first calculation unit configured to calculate an acceleration in a direction perpendicular to an extending direction of the support beam from the first value.