Patent ID: 8256292

Claim:
An acceleration sensor comprising: a piezoelectric vibrating element including a plurality of flat rectangular piezoelectric substrates stacked in a thickness direction and charge detecting electrodes respectively disposed on opposite principal surfaces thereof; a pair of principal-surface spacer members respectively disposed on the opposite principal surfaces of a first longitudinal end of the piezoelectric vibrating element; a pair of rectangular principal-surface protection members whose end surfaces at first longitudinal ends and second longitudinal ends thereof are respectively flush with end surfaces at the first longitudinal end and a second longitudinal end of the piezoelectric vibrating element, the pair of rectangular principal-surface protection members being respectively spaced apart from the opposite principal surfaces of the piezoelectric vibrating element by the pair of principal-surface spacer members; a pair of end-surface spacer members respectively disposed on the end surfaces at the second longitudinal ends of the pair of principal-surface protection members; an end-surface protection member spaced apart from the end surfaces at the second longitudinal ends of the pair of principal-surface protection members by the end-surface spacer members; a pair of side-surface spacer members respectively disposed on opposite side surfaces of the first longitudinal end of the piezoelectric vibrating element as well as on opposite side surfaces of the pair of principal-surface protection members and the end-surface protection member; and a pair of side-surface protection members respectively spaced apart from the opposite side surfaces of the piezoelectric vibrating element, the pair of principal-surface protection members, and the end-surface protection member by the pair of side-surface spacer members, wherein the end surface spacer members include respective surfaces that contact the rectangular principal-surface protection members, said respective surfaces being coplanar with the second longitudinal end of the piezoelectric vibrating element.