Patent ID: 9644994
Date: 2017-05-09
CPC Classifications: G01D,G01R

Claim:
1. A magnetic sensor for detecting a position or movements of a magnet in a first direction, comprising: a magnet magnetized in the first direction, the magnet generates a magnetic field component in the first direction; two parallel magnetic sensor elements, wherein the two parallel magnetic sensor elements extend in the first direction, wherein the two parallel magnetic sensor elements are spaced apart from each other in a second direction orthogonal to the first direction, the two parallel magnetic sensor elements facing the magnet in a third direction orthogonal to the first direction and the second direction, wherein the magnet being a separate piece from the two parallel magnetic sensor elements and the magnet being detachably movable in anyone of the first direction, the second direction and the third direction relative to the two parallel magnetic sensor elements; a soft magnetic body extending in the first direction and separately disposed between the magnet and the two parallel magnetic sensor elements in the third direction, wherein the soft magnetic body is located directly above and overlapping between the two magnetic sensor elements in the second direction, wherein a magnetic field component is generated in the third direction from the magnet due to the soft magnetic body, wherein the two parallel magnetic sensor elements each having a fixed magnetic layer in which magnetization is fixed, all of the magnetization directions of the fixed magnetic layers of the two parallel magnetic sensor elements are directed in the second direction, and a free magnetic layer in which magnetization changes due to an external magnetic field, and are provided in a range in which magnetic flux generated from the magnet saturates magnetization of the free magnetic layers of the two parallel magnetic sensor elements, wherein magnetization directions of the fixed magnetic layers of the two parallel magnetic sensor elements are the same as each other, wherein the magnetic field generated in the first direction and the magnetic field generated in the third direction are superimposed in a free magnetization direction, such that the two parallel magnetic sensor elements detect the position and movements of the magnet in the first direction while suppressing occurrence of errors caused by other movements of the magnet relative to the two parallel magnetic sensor elements in the second direction or the third direction; and a bridge circuit configured with the two parallel magnetic sensor elements for outputting a voltage to indicate the detected position or movements.