| 摘要 |
PURPOSE:To improve position control resolution by feeding back an output of a sensor by performing differentiation in terms of time and preventing resonance by controlling current which is supplied to coil by a power supply according to the fed back signal. CONSTITUTION:A position target value is input to a control device 11, an output according to it is supplied to a current source 12, and current with which a current source 12 attains the position target value is supplied to a moving coil 3. The force generated in the moving coil 3 allows a stage 6 to be driven and the position changes. A position of the stage 6 is detected by a position detector 8, which is fed back to the control device 11. When a moving coil 3 itself is distorted due to force which is applied to the moving coil 3, a gap between a gap sensor 4 and the coil 3 changes, the gap sensor 4 detects the gap change, and a differential value of the gap change is fed back to the control device 11, thus preventing resonance. |
