| 摘要 |
PROBLEM TO BE SOLVED: To provide a means for sensing a rotation position of a rotating and moving object in a non-contact manner. SOLUTION: A ringlike permanent magnet magnetized in the axial direction is sandwiched by two respective magnetic plates from the above and the below, two upper and lower protruding magnetic bodies are provided each in both end parts of the magnetic plates between upper and lower magnetic plates, and a magnetism sensing element is inserted into an air gap between two upper and lower protruding magnetic bodies, respectively. Consequently, magnetic flux from the ringlike permanent magnet is substantially restricted in the protruding magnetic bodies and passes through the magnetism sensing element. An amount of this magnetic flux is substantially proportional to a rotation angle of the ringlike permanent magnet to sense a rotation position of the ringlike permanent magnet and, accordingly, a rotation position of a rotary shaft supporting the ringlike permanent magnet in a non-contact manner from signal output detected by the magnetism sensing element. As a result, it is possible to provide a highly precise non-contact type rotation position sensor having high sensitivity because magnetic flux can be effectively collected in a mounting part of the magnetism sensing element.
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