| 摘要 |
PROBLEM TO BE SOLVED: To accurately obtain a detection value such as an amount of displacement and a position regardless of a phase relationship between a plurality of periodic patterns having a mutually different period.SOLUTION: A encoder comprises: a scale 10 that has a plurality of periodic patterns mutually different in a period provided; a sensor 20 that is capable of a relative displacement to the scale and outputs a plurality of periodic signals including a period in accordance with the plurality of periodic patterns; a signal processing unit 30 that obtains an amount of detection displacement serving as a detection value of an amount of relative displacement between the scale and the sensor using the plurality of periodic signals. The signal processing unit is configured to use each of the plurality of periodic signals corresponding to each periodic signal as a unit use each of the plurality of periodic signals to obtain an accumulation amount of displacement serving as an accumulation value of the amount of relative displacement between the scale and the sensor, letting one-integer of a period of the periodic pattern corresponding to each periodic signal be a unit, align the unit of a plurality of obtained accumulation amounts of displacements, using each of the plurality of periodic signals, and obtain an amount of detection displacement from the plurality of accumulation amounts of displacements having the unit aligned. |
