Position finely adjusting apparatus

Fast acting composite coarse and fine position adjusting apparatus comprising a stationary frame, first and second movable stages respectively arranged to be movable along first and second axes intersecting at right angles in a plane, dynamic electro-mechanical transducer means mounted on respective axial ends of the respective stages, first resilient supporting means for supporting said first stage on said stationary frame to be movable in the direction of said first axis, second resilient supporting means mounted on said first stage for supporting said second stage to be movable in the direction of said second axis, means mounted on said second stage for supporting an object whose position is to be adjusted within very fine tolerances, combined coarse and fine position measuring electrode means coacting with the respective stages for deriving output electric signals representative of the position of the respective stages, feedback control means responsive to the output electric signals from the position measuring electrode means for controlling operation of said dynamic electro-mechanical transducer means, direct current supply means supplying selected ones of the dynamic electro-mechanical transducer means under the control of the feedback control means for displacing the first and second movable stages along the respective first and second axis of movement in an essentially steady state manner, and alternating current supply means supplying other ones of said dynamic electro-mechanical transducer means under the control of said feedback control means for imparting limited vibratory motion to the first and second stages along their respective axis of movement whereby the position measuring electrode means is enabled to derive output electric signals representative of the position of the respective stages over a wide range of displacement and the position of the stages is adjusted within very fine tolerances.