| 摘要 |
PROBLEM TO BE SOLVED: To provide an origin detector which is so designed as to be capable of performing origin detection with a higher accuracy than conventional devices, by using particularly a magnetoresistance element having a fixed magnetism layer and a free magnetism layer. SOLUTION: At the time when the center 1c of a magnet 1 is in the sphere of the origin detection, a horizontal magnetic field component H1 acts on the free magnetism layer of each magnetoresistance element. Therefore it is possible to direct the free magnetism layer toward the direction of the horizontal magnetic field thereof, to stabilize magnetization, to make hysteresis small enough and to perform the origin detection with high accuracy. When the center 1c of the magnet 1 is in the sphere of the origin detection, a differential output is generated, and when the center leaves the sphere, the differential output becomes zero. Accordingly, the origin detection can be performed by determining the presence of the differential output, and the origin detection with high accuracy can be performed by such a simple circuit arrangement as not necessitating a reference voltage setting circuit. COPYRIGHT: (C)2009,JPO&INPIT
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