| 摘要 |
<p>This invention is directed to electro-magnetic alignment apparatus which includes a monolithic stage, a sub-stage, an isolated reference structure, force actuators interposed between the monolithic stage and the sub-stage for suspending and positioning the monolithic stage in space, sensors for sensing the position of the monolithic stage and outputting a signal to control circuitry, which compares the sensed position with a commanded stage position and outputs an error signal to the force actuator, and actuators for controlling the position of the sub-stage to follow the approximate position of the monolithic stage.</p> |
