| 摘要 |
PROBLEM TO BE SOLVED: To reduce effect of stain or dust on an optical scale in a position detector.SOLUTION: A position detector includes: first optical position detection means 103, which is used in combination with an optical scale 101 provided with a plurality of periodic patterns with the different periods, and generates a plurality of first detection signals that change in periods in accordance with the periods of the periodic patterns upon the reception of light from the periodic patterns when moving relative to the optical scale along with the movement of a movable member 102; second non-optical position detection means 108 for generating a second detection signal that changes along the movement of a movable member 110; and calculation means 106 for generating a signal representing the absolute position of the movable member by generating a first position signal using the first detection signals, generating a second position signal with different resolution from that of the first position signal with the use of the second detection signal, and calculating to combine the first position signal and the second position signal.SELECTED DRAWING: Figure 1 |
