| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetism detector that is not required to have a magnetoresistive element accurately assembled to a hollow part in a bias magnet, but has high sensitivity and also has wrong detection suppressed.SOLUTION: The magnetism detector comprises: magnetoresistive elements (31 and 41); a bias magnet (10) that generates a bias magnetic field to the magnetoresistive elements; and control parts (50 and 60) that detect a movement of a detected object by a change in a resistance value of the magnetoresistive elements. The bias magnet has a hollow shape, and the magnetoresistive element is provided in a hollow part (11) of the bias magnet. The magnetoresistive element has a first magnetoresistive element (41) and a second magnetoresistive element (31) arranged closer to a detected object side than the first magnetoresistive element. When magnetic flux density to be applied to the second magnetoresistive element is more than saturation magnetic flux density, the control part uses the second magnetoresistive element, and when the magnetic flux density to be applied to the second magnetoresistive element is less than the saturation magnetic flux density, the control part uses the first magnetoresistive element. |
