| 摘要 |
PURPOSE:To simplify the structure and to improve the rigidity by securing piezoelectric elements movable in X and Y directions directly to a stage such that they are secured to both parallel face of frame through piezoelectric elements and moved through inching motion. CONSTITUTION:When a stage 1 is secured, a fixing piezoelectric element 2 is extended to push upper and lower parallel faces and secured, while when it is moved, a fixing piezoelectric element 3 on a crank base 6 is extended to secure the base, then the element 2 is shrinked to bring out a movable state. The stage 1 is moved when piezoelectric elements 4 movable in X or Y direction extends by required amount at one side of the stage 1 and shrinks at the other side. Consequently, drawback of piezoelectric element, i. e. hysteresis error, is cancelled. In case of micro movement, displacement of the element 4 is controlled to drive the stage 1 directly, while in case of long distance movement, inching motion is repeated to move the stage 1 near to a target position, then accurate positioning is made through control of displacement of the element 4 thus realizing accurate positioning. |
