| 摘要 |
PURPOSE:To enhance and stabilize the sensitivity by providing a hard magnetic body which not only generates the second magnetic flux to give the second bias magnetic field to a magneto-resistance effect magnetosensitive part but also allows the second magnetic flux to pass a magnetic yoke which cancels a magnetic flux passing the magnetic yoke out of the first magnetic flux. CONSTITUTION:A thin film-shaped hard magnetic body 14 is provided just under and near an MR magnetosensitive part 5 through an insulating layer 4 formed on a bias conductor 3 so that the hard magnetic body 14 is covered with the part 5. An Ni-Co alloy or the like which has not a high magnetic resistivity but has such magnetic resistivity that magnetization is not inverted by an external magnetic field is used as materials of this hard magnetic body 14. The hard magnetic body 14 is so magnetized that a magnetic flux MF2 from the hard magnetic body 14 passes a magnetic circuit forming a closed magnetic path passing of a magnetic base body 1, a magnetic gap (g), a magnetic layer 7, an MR magnetosensitive part 5, the magnetic layer 7, and the magnetic base body 1 in the surface direction and respective magnetic fluxes passing the MR magnetosensitive part 5 out of the magnetic flux MF2 and a magnetic flux MF1 generated by power supply to a bias base body 3 and the MR magnetosensitive part 5 are added to cancel respective magnetic fluxes passing a magnetic yoke 8. Thus, the sensitivity is enhanced and stabilized.
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