| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a magnetic encoder which achieves both the functions of detection of rotation and detection of origin, even in inside a narrow space and avoids cost increase, and to provide a tone wheel to be used for it. <P>SOLUTION: The magnetic encoder comprises the magnetic annular tone wheel 10 and a detection means 11 for detecting magnetic change, accompanied by the rotation of the tone wheel. The tone wheel 10 comprises a first region 10a, where a plurality of N-poles and S-poles are magnetized alternately and repeatedly in the circumferential direction and a second region 10b, which is concentric with the first region 10a and has a missing part 10c at a part in the circumferential direction. The detection means 11 comprises a first detection member 12, which is placed facing the first region 10a and detects the rotational pulse signal, accompanying magnetic changes of the N-poles and the S-poles accompanying the rotation of the tone wheel 10 and a second detection member 13, which is placed facing the second region 10b and detects the origin point signal caused by magnetism changes of the missing part and non-missing part accompanying the rotation of the tone wheel 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
