| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce an error of a detection angle due to a noise magnetic field while decreasing installing places of a magnetic detection element. <P>SOLUTION: A magnetic field generating part 2 generates a rotation magnetic field which includes a part magnetic field MF1 at a first position and a part magnetic field MF2 at a second position. The part magnetic fields MF1 and MF2 have directions 180° different from each other and rotate in the same rotating direction. A detecting part 10 disposed at the first position has first and second detection circuits in which the phases of output signals are different only by a one-quarter period. A detecting part 20 disposed at the second position has third and forth detection circuits in which the phases of output signals are different only by a one-quarter period. A detection value of an angle which a direction at a reference position makes in regard to a reference direction of the rotation magnetic field is calculated on the basis of a first signal produced by the output signals of the first and third detection circuits and a second signal produced by the output signals of the second and forth detection circuits. <P>COPYRIGHT: (C)2012,JPO&INPIT |
