| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the problems of bouncing, damaging, stripping, charging, and positional shift of an object, when detaching the object from an electrostatic attraction stage. SOLUTION: DC voltages having different polarity are applied by attraction power supplies 141, 142 to a pair of attraction electrodes 131, 132 in a dielectric block 12, to electrostatically suck a sheet-like object 9 by inducing static electricity on an electrostatic attraction plane 10. When detaching the object 9 from the electrostatic attraction plane 10 by a detaching mechanism 15, a preload which is a mechanical pressure directed oppositely to an electrostatic attraction force, and smaller than a residual attraction force, is applied to the object 9. After turning off the attraction power supplies 141, 142, a voltage of reversed polarity to that when the electrostatic attraction is applied to the pair of attraction electrodes 131, 132 to set a reverse electric field for the dielectric block 12. The remaining charge in the dielectric block 2 is quickly relaxed by the reverse electric field setting, and the object 9 is separated apart from the electrostatic attraction plane 10 by the preload just before the remaining charge is turned into zero, and the electrostatic attraction force acting on the object 9 is turned into zero. COPYRIGHT: (C)2009,JPO&INPIT |
