| 摘要 |
PROBLEM TO BE SOLVED: To realize a structure for accurately measuring the rotation speed of a rotary member in real time especially without increasing costs. SOLUTION: A specified region 9 having a large pitch error to the extent that it is not generated by magnetization errors is provided at one portion of an encoder 7a made of a permanent magnet. By utilizing the specified region 9, the pitches of the S and N poles of the part of a non-specified region 10 and a phase related to the rotational direction are associated and are stored in a memory. In rotational speed detection, a rotational speed is calculated, on the basis of the actual pitch and the period of the output signal of a rotational speed detection sensor. COPYRIGHT: (C)2005,JPO&NCIPI
|
