| 摘要 |
PROBLEM TO BE SOLVED: To detect a reference position with high accuracy.SOLUTION: An encoder device comprises a scale having a reference position pattern indicating a reference position and a positional information pattern; a light source that irradiates the scale with light; a modulator that generates a modulation signal for modulating the light; a positional information detector that detects positional information on the scale on the basis of a positional information signal resulting from detection of the positional information pattern with the modulated light whose modulation is based on modulation according to the modulation signal; a reference position light receiver that outputs a detection signal resulting from detection of the reference position pattern with the modulated light; and a reference position detector that detects the reference position on the basis of the detection signal. The reference position detector is provided with a compensator that compensates for any displacement of the reference position arising from the modulation of light. |
