Patent ID: 6809460
Filing Date: 2004-10-26
Classification: B23Q,F16H

Abstract:
A position control apparatus comprising:a base member; a vibration wave motor having a stator, and a rotor having a rotating shaft; a driven member movable relative to said base member in a predetermined direction; and a threaded shaft coupled to the rotating shaft of said rotor and said driven member, said threaded shaft being rotatable to move said driven member in the predetermined direction; wherein when said driven member is to be moved, said vibration wave motor is actuated to cause said threaded shaft to be elastically deformed due to a frictional force exerted between said threaded shaft and said driven member and a rotating force of said rotor, before said threaded shaft starts to be rotated, and when said driven member is to be stopped, the rotating shaft of said rotor of said vibration wave motor is caused to be fixed in position due to a frictional force exerted between said stator and said rotor to keep said threaded shaft elastically deformed.