JP2000240717A - Active vibration resistant device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut a vibration transmitting route while forming the electrical wiring of a vibration detecting means into the wireless structure by fitting a vibration detecting head and a transmitter means to a vibration resistant base, and fitting a receiver means to a part except for the vibration resistant base. SOLUTION: A vibration detecting head 8, a transmitter 9 and a regulator 17 are provided on a vibration resistant base. On the other hand, a receiver 12 and a power source oscillator 14 are fitted to members except for the vibration resistant base, for example, an electrical lack. Namely, the signal for showing the vibration of the vibration resistant base picked up by the vibration detecting head 8 is transmitted on the wireless to a place except for the vibration resistant base. Acceleration signal of each part of the vibration resistant base obtained from the receiver 12 is appropriately filtered when necessary so as to eliminate the high frequency noise, and quickly input to a computing means for extracting the movement mode related to the acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration isolator. Particularly, the present invention relates to an active vibration isolator that is preferably used as a constituent unit of a semiconductor exposure apparatus having an XY stage for semiconductor exposure, and suppresses vibration transmitted to a vibration isolator, in particular, fine vibration. It relates to an intended active vibration isolator.

[0002]

2. Description of the Related Art The role of a vibration isolator is to suppress transmission of floor vibration to a vibration isolator. In recent years, in order to respond to the demand for high precision and high speed of precision equipment mounted on the vibration isolation table, active vibration isolation devices that suppress the vibration on the vibration isolation table by actively operating the actuator have been used. is there.
An active anti-vibration device has excellent characteristics as compared with a passive anti-vibration device, but it cannot completely shut off transmission of vibration of a floor on which the active anti-vibration device is installed to the anti-vibration table. Examples of the vibration transmission path include a mechanism for supporting the vibration isolation table, specifically, a mechanical spring and a viscous element of the mechanism. In an active vibration isolator, vibration transmitted through a support mechanism that supports the vibration isolation table picks up vibration of the floor with an appropriate vibration detection unit and feeds it through a transmission model of the support mechanism. It can be suppressed by control technology. So-called,
This is a technique called floor vibration feed forward or ground motion feed forward. By applying this feedforward, transmission of floor vibration to the vibration isolation table can be suppressed to some extent. For example, a maximum suppression effect of about 15 [dB] is obtained near the natural frequency of the vibration isolation table.

However, there is a floor vibration transmission path in addition to a path for transmitting floor vibrations, such as a support mechanism for a vibration isolation table, which has a clear nature and orientation. For example, cables to precision equipment or vibration detecting means mounted on the vibration isolation table. This generically refers to electrical wiring and piping for air or cooling medium. Since these cables are connected from the floor or an object rigidly connected to the floor to precision equipment on the vibration isolation table, they can serve as a vibration transmission path to the vibration isolation table, and the vibration isolation rate (floor of the floor) The rate of transmission of the vibration to the vibration isolation table is shown by frequency characteristics). For example, when the cables are in contact with a vibration source (for example, a rotary machine), the vibration is transmitted through the cables and the vibration isolator also vibrates. Such a continuous vibration transmitted to the vibration isolation table can be attenuated only at the suppression ratio indicated by the frequency characteristic of the vibration isolation rate specific to the active vibration isolation device, no matter how much the feedback parameter is adjusted. Moreover, it is difficult to cancel such vibrations by applying a control technique such as the above-described floor vibration feed forward.
Of course, when the cables are soft, the transmission of vibration to the vibration isolation table is not remarkable. However, in reality, cables form a thick bundle, and mechanically have sufficient rigidity. Therefore, it behaves like a mechanism member for transmitting vibration.

Japanese Patent Application Laid-Open No. 10-223527 (exposure apparatus) discloses a viewpoint that the positioning characteristics (positioning time and position accuracy) of an XY stage in a semiconductor exposure apparatus are not affected by cables. From
A cable relay section is provided, and means for moving the cable relay section following the XY stage is provided. There is a contrivance that the spring force of the cables that are routed by the movement of the XY stage becomes constant regardless of the movement position of the stage. However, the above publication is devised in order to prevent a tension or a repulsive force due to the resiliency of the cables drawn by the movement of the XY stage from being generated. Therefore, it can be said that there is no focus on blocking or reducing the vibration that enters the precise XY stage using the cables as a transmission path. The present invention does not aim to prevent the pulling force or the repulsive force due to the spring property of the cables from being generated, and pays attention to the fact that the cables serve as a path of vibration transmission and affect precision equipment. This is to prevent this.

In an active vibration isolator, an acceleration sensor as vibration detecting means and a number of position sensors as position detecting means are used. First, the latter sensor
The floor measures the position where the anti-vibration table is located based on a reference defined for a rigid structural member and uses it as a feedback signal for control. Therefore, the displacement of the anti-vibration table can be measured by mounting the position sensor on the floor side, and the electric wiring of the position sensor can be mounted on the floor side. That is, the electric wiring of the position sensor can be mounted so as not to be a transmission path of the floor vibration transmitted to the vibration isolation table. Also, electrical wiring for the actuator can be provided on the floor side. The servo valve for supplying and exhausting the working fluid to and from the air spring actuator can be mounted on the floor side and provided with electrical wiring and piping for it. In the case where a linear motor, which is a typical example of an electromagnetic motor, is used together with an air spring actuator, a winding coil requiring electric wiring can be mounted on the floor, and a permanent magnet can be mounted on the vibration isolator.

However, regarding the acceleration sensor,
It must be installed on the anti-vibration table side of the anti-vibration target.
Therefore, the electric wiring of the sensor can be a path for transmitting vibration. Of course, a single sensor alone does not provide a significant vibration transmission path. However, in the case of a large-scale active vibration isolator that controls the motion posture of the vibration isolation table with six degrees of freedom, the electrical wiring appears to be different from its original role. What is necessary is that at least six acceleration sensors are required to control the movement posture with six degrees of freedom, and a compact electrical connection to the control board for controlling the anti-vibration table is required. Therefore, the electric wires of the plurality of acceleration sensors are bundled. Other pipes may be bundled together with the electrical wiring of the sensor as cables. At this time, the bundled cables have appropriate rigidity. That is, unfortunately, it acts as a path for transmitting vibration to the vibration isolation table. Of course, it is clear that the electric wiring of each acceleration sensor may be provided with slack and the wiring may be individually led from the vibration isolation table side to the control board. In this case, since the individual electric wires are sufficiently soft and slack so as not to restrain the movement of the vibration isolation table at all, the vibration transmitted to the vibration isolation table can be reduced to some extent. However, the mounting of such electric wiring is limited to a case where there is room in space utilization. In a semiconductor exposure apparatus, the space is used densely, and it is not permissible as a practical matter to make the electric wiring slack. This is because an accident involving a movable mechanism installed near the anti-vibration table may be caused.

Referring again to a specific drawing, it will be described again that the electric wiring serves as a vibration transmission path to the vibration isolation table. FIG. 2 is an example of the electrical mounting of the active vibration isolation device. In the figure, 1 is a vibration isolation table, 2R and 2L are vertical acceleration sensors as representatives of vibration detecting means, 3R and 3L are horizontal acceleration sensors as representatives of vibration detecting means, 4R and 4L.
Is a vertical air spring actuator (the horizontal air spring actuator is not shown), and 5 is a floor. Here, R and L indicate the mounting portions of the active support legs including the air spring actuator 4 supporting the vibration isolation table 1 and the like. As shown in the figure, vertical and horizontal acceleration sensors 2 and 3 are respectively installed at parts R and L, and these electric wirings become bundled wires 6 and extend from the vibration isolation table 1 toward the floor 5. ing. The bundle 6 on the floor side is connected to a control board (not shown). Therefore, the vibration existing on the floor 5 is transmitted to the vibration isolation table 1 using the bundled wire 6 as a transmission path. In the case of FIG. 2, the vibration of the floor is transmitted to the vibration isolation table 1. However, when the bundled wire 6 is mounted on a not-shown relay member, the vibration of the relay member is Is transmitted to the anti-vibration table 1 via the.
In any case, the fact remains that the bundle 6 serves as a path for transmitting vibration to the vibration isolation table 1. In fact, when measuring vibrations on the order of micro G, the phenomenon that the measured value fluctuates when the wiring of the acceleration sensor is routed or the bundle is changed can be easily observed. It is certain that there is a vibration. It should be noted that such transmission of vibrations is provided by the acceleration sensor itself provided for actively controlling the vibration isolation table.

In order to suppress the transmission of vibration to the vibration isolation table,
It is necessary to eliminate the electrical wiring of the acceleration sensor that serves as a vibration transmission path. Of course, since the power must be supplied to extract the acceleration output, the electric wiring for that is indispensable. However, recent advances in electronic technology have brought about the emergence of vibration detection means for wirelessly supplying power and transmitting and receiving signals. The present invention provides an active vibration isolator in which the electric wiring of an acceleration sensor as a vibration detection means indispensable for active control is made wireless, and transmission of vibration to the vibration isolation table is eliminated as much as possible. The purpose is to:

[0009]

Conventionally, in an active vibration isolator, a closed loop system in which an actuator is driven based on an output of a vibration detecting means provided on a vibration isolation table is configured. By appropriately feeding back the output of the vibration detecting means, transmission of floor vibration to the vibration isolation table can be suppressed. However, as a high-precision positioning device or measuring device is mounted on the vibration isolation table, it is necessary to pay attention to the micro-vibration transmitted to the vibration isolation table and remove it. As one of the microvibrations transmitted to the vibration isolation table, there is one that uses wiring as a path. Ironically, the vibration is transmitted from the electric wiring of the vibration detection means itself, which is essential for suppressing the vibration of the vibration isolation table.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an active anti-vibration apparatus in which electric wiring such as vibration detecting means is made wireless to cut off a vibration transmission path.

[0011]

According to the present invention, there is provided an actuator for applying a driving force to a vibration isolation table, vibration detection means for detecting vibration of the vibration isolation table, In an active vibration isolator including a control unit that drives the actuator by feeding back an output of the vibration detection unit, the vibration detection unit includes a vibration detection head that detects vibration of the vibration isolation table and an output of the vibration detection head. Transmitting means for converting the signal into an electromagnetic wave signal and transmitting the signal;
Receiving means for receiving the transmission signal, the vibration detection head and the transmission means are attached to the vibration isolation table,
The receiving means is attached to a portion other than the vibration isolation table.

[0012] In addition to the feedback based on the output of the vibration detecting means, for example, a feedback based on the output of the position detecting means may be provided.

[0013]

In a preferred embodiment of the present invention, the vibration detecting means includes an induction power supply for supplying power to the vibration detecting head and transmitting means wirelessly from a portion other than the vibration isolation table. Further, the electromagnetic waves are radio waves or light. Hereinafter, embodiments of the present invention will be described more specifically through examples.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preparation for explaining the active vibration isolator of this embodiment in detail, wireless remote measurement of temperature, stress, pressure, vibration (acceleration or speed), torque, voltage, etc. of a rotating or moving body is performed. An industrial wireless measuring device (telemetry system) as a system will be described.

FIG. 3 shows a device configuration of a vibration detecting means for wirelessly detecting the vibration (more specifically, the acceleration) of the object 7 to be measured. In the figure, reference numeral 8 denotes a vibration detection head attached to a measurement target 7, and the output is guided to a transmitter 9. Here, a radio wave is transmitted from the antenna 10 through the signal conversion unit and the transmission modulation unit. This radio wave is received by the antenna 11 and demodulated by the receiver 12 to output an electric signal. Here, an analog output is obtained at the terminal 13 via the reception demodulation unit and the signal conversion unit in the receiver 12. Here, the power supply to the vibration detection head 8 and the transmitter 9 employs an inductive power supply system. That is, an alternating current is generated by the power oscillator 14, which enters the fixed primary coil 15 to generate an alternating magnetic field. This magnetic field is picked up by the pickup coil 16 and the regulator 1
At 7, the power is rectified to a DC power supply, and power is supplied to the vibration detection head 8 and the transmitter 9. As described above, the above-described telemetry system relating to acceleration is characterized by being wireless without using electric wiring for power supply and transmission / reception of signals.

In this embodiment, as will be described later in detail, the above-described vibration detecting means is provided for measuring horizontal and vertical vibrations at a plurality of locations on the vibration isolation table. Conventionally, the electric wiring of the acceleration sensor has been used as a path to transmit unnecessary vibrations to the vibration isolation table. However, the use of the vibration detecting means in FIG. Can be blocked.

The power supply by the induction power supply system may be provided for each vibration detection head, but it is sufficient that at least one power supply is provided for a plurality of vibration detection heads mounted on the vibration isolation table. It is not always necessary to provide as many receivers as the number of vibration detection heads mounted on the vibration isolation table for receiving the signals from the vibration detection heads by radio waves. The signal from the transmitter for each vibration detection head can be received and reproduced by one receiver in a time-division manner. Moreover,
It is not always necessary to provide as many transmitters as the number of vibration detection heads mounted on the vibration isolation table. Signals from a plurality of vibration detection heads can be transmitted in a time-division manner by one transmitter.

First, FIG. 4 shows an example of the mechanical configuration of the active vibration isolator of the present embodiment. In the figure, reference numeral 40 denotes an XY stage mounted on the vibration isolation table 41, and reference numerals 42-1, 42-2, and 43-3 denote active support legs for supporting the vibration isolation table 41. In one active supporting leg 42, the necessary number of vibration detecting heads AC, position sensors PO, pressure sensors PR, servo valves SV, air spring actuators for controlling two axes in the vertical and horizontal directions are provided. AS is built-in. Where AC,
Symbols attached next to PO and the like indicate the orientation according to the coordinate system in the figure and the location of the active support leg 42. For example, Y2 is the active support leg 42-2 arranged on the left side in the Y-axis direction.
Refers to something inside.

Next, the wireless vibration detecting means is activated.
Active vibration removal of this embodiment in which the vibration isolation table 41 is supported by three support legs.
FIG. 1 shows a configuration when applied to a vibration device. Control of the same figure
The structure itself is disclosed in JP-A-9-68995.
It is the same as shown. Acceleration filter for vibration suppression
Feedback loop and position feedback for localization
In addition to the loop, measure the internal pressure of the air spring actuator.
Pressure feedback meter that measures and feeds back this
Are provided. Here, PO-Z1, PO-Z
2, PO-Z3, PO-X1, PO-Y2, PO-Y3
Is a position detecting means, and its output is a position target value output unit 2.
1 (Z_Ten, Z₂₀, Z₃₀, X _Ten, Y₂₀,
Y₃₀) Is compared with the position deviation signal (e) of each axis._Z1,
e_Z2, E_Z3, E_x1, E_y2, E_y3). These deviations
The signal indicates the translational motion of the vibration isolation table 41 and the rotational motion about each axis.
Motion mode position deviation signal (e_x, E_y, E
_z, Eθ_x, Eθ_y, Eθ_z) Is calculated.
To the exercise mode extraction calculating means 22. these
The output signal is almost non-interfering with the position characteristics for each motion mode.
Is adjusted to the gain compensator 23 related to the position for adjusting.
This loop is called a position feedback loop.

Next, the vibration detecting heads AC-Z1, AC-
Z2, AC-Z3, AC-X1, AC-Y2, AC-Y
The feedback loop based on the output of No. 3 will be described. These vibration detection heads detect acceleration or speed. Here, it is assumed that the acceleration is detected. The signal detected by the vibration detection head AC is converted into a radio wave in the transmitter TR described above. Power is supplied from the regulator 17 to each transmitter TR and the vibration detection head AC. The regulator 17 fixes the AC magnetic field of the power oscillator 14 to the primary coil 1.
5 and detected by the pickup coil 16 to obtain electric power.

Here, the mounting portion of the unit constituting the vibration detecting means will be clarified again. The vibration detection head AC, the transmitter TR, and the regulator 17 are installed on the vibration isolation table 41. On the other hand, the receiver RC and the power oscillator 14 are attached to a member other than the vibration isolation table 41, for example, to an electrical equipment rack. That is, the vibration detection head A
The signal representing the vibration of the vibration isolation table 41 picked up at C is
The data is transmitted wirelessly to a place other than the vibration isolation table 41. That is, in the related art, the transmitter TR, the transmitter TR, and the like are so arranged that the vibration transmitted through the electric wiring of the vibration detection head AC itself for detecting the vibration of the vibration isolation table 41 is cut off.
Receiver RC, regulator 17, power oscillator 14
Is installed in the exposure apparatus main body 34 including the vibration isolation table 41.
Then, the acceleration signal of each part of the vibration isolation table 41 obtained from the receiver RC is subjected to appropriate filtering processing such as removal of high-frequency noise as required, and is immediately input to the motion mode extraction / calculation means 24 relating to acceleration. Becomes Its output motion mode acceleration signals _{(a x, a y, a} z, aθ x,
aθ _y , aθ _z ). Here, in order to set the optimal damping for each exercise mode, the exercise mode acceleration signal (a
_x , a _y , a _z , aθ _x , aθ _y , aθ _z ) are guided to the gain compensator 25 for the acceleration signal of the next stage. By adjusting this gain, an optimum damping characteristic can be obtained for each exercise mode. Then, the feedback is provided to the preceding stage of the PI compensator 26 relating to the acceleration. This feedback loop will be called an acceleration feedback loop.

Further, the signal obtained by adding the negative feedback signal of the acceleration feedback loop to the output of the gain compensator 23 described above passes through the PI compensator 26 and outputs the motion mode drive signals (d _x , d _y , d _z , dθ). _x , dθ _y , dθ _z ), and is led to the motion mode distribution calculating means 27 in order to obtain the driving force to be generated by the actuator of each axis, and the output thereof is the driving signal (d _z1 , d _z2) of each axis. , D _z3 , d _x1 , d _y2 , d _y3 ). The drive signal is used as an input to a pressure feedback loop applied to each axis. The principle of the pressure feedback loop is described in Japanese Patent Application Laid-Open No. 9-68995.
No. 6,009,045. The configuration will be briefly described again. The pressing force measuring means P for measuring the internal pressure of the air spring will be described.
The output of R is guided to pressure detecting means 30 for performing appropriate amplification and filtering for removing high-frequency noise, and this output is fed back to a stage preceding the PI compensator 31 relating to pressure. The zero point of the PI compensator cancels the low frequency pole in the transfer characteristic from the input of the voltage / current converter (abbreviated as VI conversion in the figure) 32 for opening and closing the servo valve SV to the internal pressure of the air spring. To be chosen. At this time, the drive signals for each axis _{(d z1, d z2, d} z3, d x1, d y2,
The characteristic from _dy3 ) to the internal pressure of each air spring is a first-order lag characteristic. That is, it becomes a stereotactic system. A bias voltage for determining the neutral pressure of the air spring actuator is applied from a target pressure value output unit 33 to a stage preceding the PI compensator 31 relating to pressure. In the above-described pressurizing force feedback loop, the internal pressure of the air spring actuator is detected by the pressurizing force measuring means PR represented by a pressure sensor, and this is fed back. However, the load generated by the air spring actuator is determined by the load sensor. The same function as the above-described pressure feedback loop can be realized when a load feedback is formed by detecting the output by load measurement means represented by the formula (1) and negatively feeding back this output. In the present embodiment, the technical content has been described using the pressure feedback loop in the pressure feedback loop.

Since the electric wiring to the vibration detecting head for measuring the vibration of the vibration isolation table 41 is made wireless by the active vibration isolation device described above, conventionally, the electric wiring is transmitted to the vibration isolation table 41 as a path. The coming vibration can be cut off.

In the above-described embodiment, radio waves are used to make the electric wiring of the vibration detection head mounted on the vibration isolation table 41 wireless. Of course, wireless means is not limited to radio waves, and optical transmission can be another wireless means. Optical transmission uses light compared to remote measurement using radio waves, and thus is less susceptible to external noise, and at the same time does not cause radio interference to other devices. Therefore, it is excellent in accuracy and stability. The device configuration is such that the transmission modulation unit of the transmitter in FIG. 3 is replaced by an optical transmission unit, and the reception and demodulation unit of a receiver is replaced by a light receiving unit. Similar to the transmission of the signal obtained by the vibration detection head by radio waves, the power supply is a non-contact inductive power supply type unit, and the number of the power supplies is inevitably provided by the number of vibration detection heads mounted on the vibration isolation table 41. It is sufficient if at least one device is provided.

In the embodiment shown in FIG. 1, only the vibration detecting means is used for wireless communication. However, only the vibration detecting means is mounted on the vibration isolation table or on a member rigidly connected to the vibration isolation table. There is no other way than it is necessary. That is, the position sensor as the position detecting means does not necessarily need to be mounted on the anti-vibration table side. However, if it is necessary to attach it to the vibration isolation table,
Of course, wireless transmission and reception of the signal and supply of power as in the above-described vibration detecting means are not hampered.
The same applies to other sensors.

In the above-described embodiment, attention is paid to the fact that the electric wiring of the acceleration sensor as the vibration detecting means used in the active vibration isolator serves as a path for transmitting vibration to the vibration isolation table. The configuration of the device for shutting off is shown. However, on the vibration isolation table, various motion mechanisms and measurement devices are installed in addition to the vibration detection head in the active vibration isolation device. These are collectively referred to as precision instruments. Naturally, bundling the electrical wiring to these precision instruments results in considerable weight and thickness. Therefore, just like the electric wiring of the acceleration sensor as the vibration detecting means becomes the vibration transmission path, the electric wiring to the precision equipment also becomes the vibration transmission path. Therefore, as shown in the embodiment, the electric wiring of the precision equipment can also be made wireless by radio waves or light, and at this time, transmission of vibration to the vibration isolation table is cut off. Needless to say, this also belongs to the present invention.

Finally, the effects of the present invention will be described. FIG.
Let us show the frequency characteristics of the vibration isolation rate of the active vibration isolation device. In the figure, the curve indicated by A is a case where the electric wiring of the vibration detecting means in the active vibration isolation device is a transmission path. On the other hand, B in the figure indicates the vibration isolation rate of the active vibration isolation device according to the present invention in which the vibration detection means is made wireless. The hatched portion is the vibration component transmitted to the anti-vibration table using the electric wiring as a medium, and it can be seen that the transmission of the vibration was interrupted by using the wireless vibration detection means according to the present invention.

[0028]

The effects of the present invention are as follows. (1) The use of vibration detection means is indispensable for active control of the vibration isolation table. However, conventionally, electric wiring of the vibration detecting means itself has been a vibration transmission path. However,
In the present invention, electric wiring to the vibration detecting means is not required, so that transmission of vibration to the anti-vibration table through the electric wiring can be cut off. Accordingly, there is an effect that the accuracy of precision equipment mounted on the vibration isolation table can be ensured. (2) Since electrical wiring can be eliminated, no space is required for mounting these components, and mounting and assembly are not required. Therefore, the semiconductor exposure apparatus itself including the active anti-vibration apparatus can be designed to be compact, and the apparatus assembling process can be shortened. (3) There is an effect that it greatly contributes to the productivity of the semiconductor exposure apparatus.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an active vibration isolator according to one embodiment of the present invention.

FIG. 2 is a perspective view showing an example of electrical mounting in the device of FIG.

FIG. 3 is a side view illustrating a device configuration of a vibration detecting unit in the device of FIG. 1;

FIG. 4 is a perspective view showing an example of a mechanical configuration of the active vibration isolator of FIG. 1;

FIG. 5 is a graph of a frequency characteristic of an anti-vibration ratio showing an effect of the active anti-vibration device according to the present invention.

[Explanation of symbols]

1: Vibration isolation table, 2R, 2L: Vertical acceleration sensor as representative of vibration detecting means, 3R, 3L: Horizontal acceleration sensor as representative of vibration detecting means, 4R, 4L: Vertical air spring actuator , 5: floor, 6: bundled wire,
7: Measurement target, 8: Vibration detection head, 9: Transmitter, 10: Antenna, 11: Antenna, 12: Receiver, 13: Terminal, 14: Power oscillator, 15: Fixed 1
Next coil, 16: pickup coil, 17: regulator, 18: induction power supply, 21: position target value output unit, 2
2: motion mode extraction calculation means, 23: gain compensator, 2
4: Exercise mode extraction operation means for acceleration, 25: Gain compensator for acceleration signal, 26: PI compensator for acceleration, 27: Motion mode distribution operation means, 30: Pressure detection means, 31: PI compensator for pressure, 32 : Voltage / current converter, 33: pressure target value output unit, 34: exposure apparatus main body, 40: XY stage, 41: anti-vibration table, 42: active support leg, AC: vibration detection head, AS: air spring actuator, PO: position detecting means, PR: pressure sensor, RC: receiver, SV: servo valve, TR: transmitter.

Claims (3)

[Claims] 1. An actuator for applying a driving force to a vibration isolation table, a vibration detection means for detecting vibration of the vibration isolation table, and a control means for driving the actuator by feeding back an output of the vibration detection means. An active vibration isolation device comprising: a vibration detection head configured to detect vibration of the vibration isolation table; and a transmission unit configured to convert an output of the vibration detection head into an electromagnetic wave signal and transmit the signal. Receiving means for receiving a transmission signal, wherein the vibration detecting head and the transmitting means are attached to the vibration isolation table, and the reception means is attached to a portion other than the vibration isolation table. Anti-vibration device. 2. The active device according to claim 1, wherein the vibration detecting means includes an induction power supply for supplying power to the vibration detecting head and the transmitting means wirelessly from a portion other than the vibration isolation table. Anti-vibration device. 3. The active vibration isolator according to claim 1, wherein the electromagnetic waves are radio waves or light.