| 摘要 |
PROBLEM TO BE SOLVED: To provide a self-weight compensating device for operating the self- weight compensation of a stage with good balance. SOLUTION: This self-weight compensating device is provided with a stage 102 for holding an object, and for moving it to the direction of gravity, plural self-weight compensating mechanism for supporting the stage 102 to the direction of gravity, plural thrust generating mechanisms for applying thrust to the stage 102, and detector for measuring the position of the direction of gravity of the stage 102 and the inclination of rotation with a direction orthogonally crossing the direction of gravity as an axis. Then, a positioning error is judged from the target position of the stage 102 and the measured value of the detector, and when the positioning error is beyond a prescribed range, the stage 102 is driven by the self-weight compensating mechanism, and when this positioning error is within the prescribed range, the stage 102 is driven by the thrust generating mechanism. Thus, the direction of gravity of the stage 102 and the inclination of the bid-directional rotation can be controlled across the whole driving strokes of the stage 102, and quick positioning can be attained by preliminarily driving the stage 102.
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