| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotation angle detector capable of preventing a rotation detection error from being generated, even if relative positional shifts are generated between a magnet and the first and second magnetic sensors. SOLUTION: The two disk-shaped magnets 2, having the same direction of magnetic flux and the same performance, are fixed onto a shaft 1 made of a magnetic substance with a prescribed space. A closed magnetic field with magnetic flux lines aligned radially is formed, in a space in a z-axis direction central part of the two magnets 2 and in the center of an outer circumferential end of the shaft 1 and an outer circumferential end in the magnets 2. The first and second magnetic sensors 3, 4 are arranged in the space formed with the closed magnetic field. The first and second magnetic sensors 3, 4 are arranged in the vicinity of a circumference of the one magnet 2 in conventional rotation angle detectors, the rotation detection errors thereby become large, because of the positional shift between the first and second magnetic sensors 3, 4; but the rotation detection errors are prevented from being generated in the constitution of the present invention, since changes in the directions of the magnetic flux lines imparted to the first and second magnetic sensors 3, 4 are restrained, even if the attachment positions for the first and second magnetic sensors 3, 4 are slightly shifted. COPYRIGHT: (C)2006,JPO&NCIPI
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