摘要 |
An acceleration sensor includes a housing member, a spring member attached to the housing member and provided with freedom in at least one direction of acceleration to be detected, a magnetic field generation member with weight fixed to the spring member, and at least one magnetic field detection sensor attached to the housing member to face the magnetic field generation member with weight. Each magnetic field detection sensor is provided with at least one pair of multi-layered MR elements each including a magnetization fixed layer and a magnetization free layer. A magnetized direction of the magnetization fixed layers is fixed to a direction parallel to the direction of acceleration to be detected. The magnetic field generation member with weight includes at least one permanent magnet that provides a closed magnetic loop. At least one pair of multi-layered MR elements is arranged in the closed magnetic loop to receive magnetic field substantially perpendicular to a lamination plane of the multi-layered MR elements when no acceleration is applied.
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