Patent ID: 8104344

Claim:
An angular velocity sensor comprising: a substrate; a mass portion; an excitation member that excites the mass portion along an excitation direction parallel to a surface of the substrate; a beam supporting the mass portion so that the mass portion is capable of being displaced at least along (1) the excitation direction, (2) a first detecting direction that is orthogonal to the excitation direction and parallel to the surface of the substrate, and (3) a second detecting direction that is orthogonal to the surface of the substrate, the beam including a first portion and a second portion, one end of the beam being connected with the mass portion and another end of the beam being connected with the substrate; a first detecting member disposed on the beam, the first detecting member detecting a vibration of the beam along the first detecting direction; and a second detecting member that directly or indirectly detects a vibration of the mass portion along the second detecting direction, wherein a spring constant of the first portion along the excitation direction is lower than a spring constant of the first portion along the first detecting direction, and a spring constant of the second portion along the first detecting direction is lower than a spring constant of the second portion along the excitation direction, the first portion is arranged closer to the mass portion than the second portion, and the first detecting member is disposed on a farther beam portion of the beam, wherein the farther beam portion is arranged farther away from the mass portion than the first portion.