| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to detect displacement of a detector in a lateral direction with respect to a scale.SOLUTION: An photoelectric absolute position detector comprises a scale 10 having a plurality of tracks 11 to 13 with patterns of different pitches; and a detector 20 having a light source, and a light receiving element including a plurality of light receiving element arrays 21 to 23 corresponding to the tracks 11 to 13. In the photoelectric absolute position detector, a light receiving element array 22' is additionally added in a position corresponding to the boundary between the adjacent tracks 11 and 12 of a rough pitch pattern and fine pitch pattern respectively in the detector 20. Displacement of the detector 20 in a lateral direction with respect to the scale 10 is detected from the signal amplitude Iamp of the added light receiving element array 22'. |
