| 摘要 |
PROBLEM TO BE SOLVED: To implement a structure which is capable of sufficiently securing responsiveness relating to measurement of a physical quantity, in an overall rotational speed range of a rotating member while preventing the occurrence of abnormality in processing of calculating the physical quantity in a state where the rotating member rotates at a high speed.SOLUTION: A pitch of first through holes 11a, 11a, and 11aconstituting a plurality of characteristic change combination parts 3a, 3a, and 3aprovided on a surface to be detected of an encoder 1a is repeatedly changed to α, &bgr;, γ(α<&bgr;<γ) in this order with respect to a circumferential direction. When the rotational speed of the rotating member is low, a physical quantity is calculated on the basis of sensor information acquired for all pitches α, &bgr;, γ. When the rotational speed of the rotating member is middle, a physical quantity is calculated on the basis of only sensor information acquired for partial pitches &bgr; and γ. When the rotational speed of the rotating member is high, a physical quantity is calculated on the basis of only sensor information acquired for the less partial pitch γ. |
