Abstract: An anti-vibration apparatus has a feedback loop based on vibration information from an anti-vibration table, and a feedforward loop based on vibration information from a setting foundation. A compensation mechanism in the feedforward loop uses an adaptive filter. The adaptive filter sequentially sets parameters in the compensation mechanism on the basis of the vibration information form the anti-vibration table and setting foundation. The vibration information consists of vibration component information indicating vibrations in units of motion directions, and a determination mechanism and an operation switching mechanism arranged at the input side of the adaptive filter select the vibration component information and supply the selected information to the adaptive filter.

Abstract: A scan-projection type exposure apparatus quickly suppresses disturbance in synchronization between a wafer stage and a reticle stage, and enables high-precision pattern exposure. This apparatus employs a master-slave control with a wafer-stage side as the master with a reticle-stage side as the slave, so as to correct a target value of a position control system of a rough-motion stage or that of a position control system of the reticle stage by using motion-mode errors e.sub.g, e.theta..sub.x and e.theta..sub.y in a one-to-one correspondence with a disturbance occurring to the rough-motion stage of the wafer stage due to movement of a fine-motion stage of the wafer stage.

Abstract: An active vibration removing apparatus having an air-spring as an actuator, includes: a vibration removing table, a supporting air-spring for supporting the vibration removing table, a servo-valve for adjusting the pressure of the air-spring, and a feedback system for controlling the servo-valve. A pseudo-differentiator pseudo-differentiates a speed adjustment signal of a device placed on the vibration removing table. A pulse selector for selects an arbitrary numbers of pulse waveforms from a series of pulse waveforms outputted from the pseudo-differentiator. The output of the pulse selector is feedforwarded in the feedback system.

Abstract: A position control system which includes a plurality of actuators for moving an object, a plurality of sensors for detecting the state of the object, a first circuit for extracting a state signal, in each of different kinetic modes related to the object, from outputs of the sensors, a compensating circuit for compensating for the state signals in the respective kinetic modes, a second circuit for distributing an output of the compensating circuit and for providing drive signals for the actuators in accordance therewith, and a driver for driving the actuators in response to the drive signals.

Abstract: A positioning system includes a plurality of actuators for driving an object to be positioned, a plurality of current output type amplifiers for amplifying drive signals from the actuators and for producing drive currents corresponding to the drive signals, and a plurality of acceleration sensors for detecting acceleration of the object in the neighborhood of the actuators. A feedback circuit negatively feeds back the outputs of the acceleration sensors to input sides of the amplifiers such that the actuators are driven in response to the drive currents.

Abstract: A precision positioning apparatus suitable for the positioning control system of a semiconductor exposing apparatus such as a stepper has, as its object, the provision of a non-contact type precision positioning apparatus capable of properly correcting the disturbance of posture or vibration based on low rigidityy which is a feature of a non-contact guide mechanism and accomplishing stable, highly accurate positioning at a high speed. The precision positioning apparatus is provided with a base plate, a movable member positioned on the base plate, a driving device for driving the movable member, a detecting device for detecting movement of the movable member, and a device for supplying the driving device with a signal regarding the movement of the movable member on the basis of a reference value and the output value from the detecting device.

Abstract: A stage driving system capable of positioning an object with a higher speed and a higher precision than prior systems. The system includes a base member, plural movable members provided on the base member, and a controller for controlling the plural movable members so as to substantially suppress the vibration of the base member caused by the displacements of the plural movable members.

Abstract: A vertical vibration elimination table apparatus has a vibration elimination table supported by actuators at four portions thereof. The actuators are operable in response to signals which are fed back thereto and which are indicative of vertical positions and vertical accelerations of the four portions of the table. A control apparatus for controlling and driving the actuators includes a 4-degree-of-freedom motion mode extraction circuit for extracting motion mode error signals of four degrees of freedom including one degree of freedom for translational motion, two degrees of freedom for rotations and one degree of freedom for twist motion, a compensation circuit for producing compensated motion mode signals by effecting compensations on the respective motion mode error signals, and a motion mode distribution circuit for producing drive signals based on the compensated motion signals and delivering the drive signals to the respective actuators.

Abstract: A control device for controlling displacement of a magnetically supported moving member according to a command. A feedback circuit detects the displacement of the moving member to servo-control the same to thereby ensure stability and robustness of magnetic supporting. A feedforward circuit has an input terminal receptive of a command and an output terminal connected to the feedback circuit, and cooperates with the feedback circuit while not disturbing the stability and robustness of the magnetic suppporting for controlling the displacement of the moving member according to the command.

Abstract: An objective lens apparatus for an optical disc player comprises an objective lens holder rotatable about a center axis, an objective lens carried by the holder at a location spaced from the center axis, an optical member, a magnetic flux generating member for generating magnetic flux, and tracking and focusing coils interacting with the magnetic flux for effecting tracking and focusing adjustments of the objective lens. The optical member rotates simultaneously with the lens holder and leads light which is incident along the center axis to the objective lens in a direction parallel to the center axis thereby eliminating optical modulation of the light caused by rotation of the lens holder in the tracking direction.