| 摘要 |
<p>PROBLEM TO BE SOLVED: To allow a rotation detection device to be applied to even a rotating body pierced by a revolving shaft and allow an absolute rotation angle of a rotating body to be detected with high resolution.SOLUTION: A rotation detection device includes rotary magnets 21 and 22 attached to a revolving shaft 10. The rotary magnet 21 has a first magnetic pattern comprising magnetic poles at equal intervals, and the rotary magnet 22 has a second magnetic pattern including a first block 22a comprising magnetic poles at equal intervals and a second block 22b having a magnetization angle different from that of the first block 22a and comprising magnetic poles at equal intervals The sum total of the numbers of magnetic poles of the first and second blocks 22a and 22b is equal to the number of magnetic poles of the first magnetic pattern. A first magnetic sensor 30 is made to face the first magnetic pattern, and second and third magnetic sensors 40 and 50 are shifted by 90° and are made to face the second magnetic pattern. Each of the first to third magnetic sensors 30, 40, and 50 outputs two detection signals different in phase by 90°.</p> |
