| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent excessive output due to interference of mechanical attitudes among respective four drive units. <P>SOLUTION: X-axis direction drive units 3x each comprising an XYθ guide 4 and a ball screw linear motion mechanism 6 in the X-axis direction are interposed at two places corresponding to one diagonal position of an upper plate 2 between a base 1 and the upper plate 2, and Y-axis direction drive units 3y each comprising the XYθ guide 4 and the ball screw linear motion mechanism 6 in the Y-axis direction are interposed at two places corresponding to the other diagonal position of the upper plate 2. Compared to the X-axis direction drive unit 3x performing feedback control based on the detection value of a linear scale 13, the Y-axis direction drive unit 3y is set to lessen servo rigidity by feedback control based on a detection value by a motor encoder 16 provided to the servo motor 12 of the ball screw linear motion mechanism 6, to thereby mechanically absorb the thrust increment due to the attitude interference by the Y-axis direction drive units 3y. <P>COPYRIGHT: (C)2012,JPO&INPIT |
