| 摘要 |
PROBLEM TO BE SOLVED: To prevent operation from becoming unstable under the effect of fine vibration when a rough movement stage which is driven by using an ultrasonic motor and a fine movement stage which is driven by using a piezoelectric actuator are used in combination since the ultrasonic motor causes fine vibration around its stop position right after the input of a driving signal is ceased although the ultrasonic motor has a self-holding characteristic. SOLUTION: Before the fine movement stage is driven by using the piezoelectric motor, a fine vibration quantity is measured and after the value becomes less than a fixed value, the fine movement stage is driven. COPYRIGHT: (C)2004,JPO
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