| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotation detecting apparatus capable of detecting reliable rotation information in various environments by securing large effective output signals. SOLUTION: In the rotation detecting apparatus, a sensor chip 1 is provided with magnetoresistive elements MRE1-MRE4, and a biased magnet 3 is arranged in such a mode as to surround the periphery of the sensor chip 1 for providing a bias magnetic field for the magnetoresistive elements MRE1-MRE4. The sensor chip 1 is resin-molded with the biased magnet 3 integrally into one piece. When a rotor 20 alternately provided with crest parts 21 and root parts 22 is rotated in the vicinity of the sensor chip 1, changes in magnetic vectors generated in cooperation with the bias magnetic field are detected as resistance values of the magnetoresistive elements MRE1-MRE4 to detect the rotation mode of the rotor 20. Such a rotation detecting apparatus is provided with a plate 5 made of a magnetic body in such a mode as to further surround the biased magnet 3 for providing a bias magnetic field for the magnetoresistive elements MRE1-MRE4. COPYRIGHT: (C)2006,JPO&NCIPI
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