| 摘要 |
<p>PROBLEM TO BE SOLVED: To accelerate high speed or high accuracy positioning operation while avoiding increase in the size of an apparatus. SOLUTION: The stage unit comprises a Y linear motor 40 of a stage drive mechanism for moving work stages 20, 30 freely movable along a reference plane in a vertical direction, a counter stage including a counter mass 61 balancing the weight of the work stages, belts 62 for linking the counter mass 61 with the work stages, a pulley 63 for supporting the belts, a linear motor 80 of a counter mass drive mechanism for moving the counter mass 61 along a vertical direction, and a measuring means. The stage unit is further provided with means for estimating the gap amount of a joint from the difference of measuring position between the work stage and the counter stage, means for setting the joint with a specified gap amount, and a joint gap controller for operating a command value to a joint control system based on these values.</p> |
