| 摘要 |
PROBLEM TO BE SOLVED: To provide an encoder disclosing a detailed configuration for hindering disturbance of a magnetic field distribution.SOLUTION: An encoder comprises: a rotor (10): and a magnetic body (50) provided in an annular form along a circumferential direction. The magnetic body includes a plurality of first magnetic pole parts (51) and second magnetic pole part (52) alternately arranged in a circumferential direction. One of the second magnetic pole parts is larger than the other second magnetic pole parts of the identical shape. At least one first magnetic pole part is provided in the formation area (53a) of the second magnetic pole part larger than the other second magnetic pole parts. Part of the first magnetic pole part is exposed out from one face (53b) of the second magnetic pole part larger than the other second magnetic pole parts. The periphery of the exposed face (51a) is surrounded by one face. |
