JP2005268293A - Micromoving mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micromoving mechanism employing gas in which high speed response can be improved. <P>SOLUTION: The micromoving mechanism 10 comprises a moving member 12 movable in a moving direction shown by an arrow, a section 14 for guiding the moving member 12 in the moving direction, a gas supply passage 18 provided in the bottom face member 16 of the guide section 14 and supplying gas to a gap in the upper surface of the bottom face member 16 where the guide section 14 faces the moving member 12, and a control section 20 causing predetermined micromovement of the moving member 12 in the arrow direction by controlling gas pressure being supplied to the gas supply passage 18. The gas having a gas pressure regulated at the control section 20 is led to the inlet of the gas supply passage 18, passed through a restriction part 26, and jetted from an opening provided in a gas receiving wall 24 toward the gas receiving surface 22 of the moving member 12. The moving member 12 floats from the gas receiving wall 24 to form a gap. Amount of the gap is controlled by the supply gas pressure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a moving mechanism, and more particularly to a minute moving mechanism having a moving amount on the order of μm.

  As actuators using fluid pressure, those represented by a piston and cylinder mechanism are well known. As shown in Patent Document 1, the fluid pressure actuator can drive the moving body by controlling the fluid pressure using a fluid pressure servo mechanism. In particular, a gas pressure actuator that uses a gas such as air is expected as a positioning device that is less likely to cause contamination and easier to handle than an actuator that uses oil pressure. By the way, generally used gas pressure actuators are not very responsive. The spring constant of the gas pressure actuator tends to decrease as the volume of the gas chamber increases, and decreases as the compression rate of the gas used increases, but there is a limit to reducing the volume of the air chamber in the cylinder. Because.

  Therefore, in order to improve the responsiveness of the gas pressure actuator, it is considered to introduce a member having a high spring constant into the drive unit. For example, Patent Document 2 discloses that the movable frame is moved using a bellows that expands and contracts by air pressure. However, the bellows can be made of metal. Since the spring constant of the metal bellows is determined by the shape of the metal bellows and the elastic constant of the metal used, it can be set to a value larger than the spring constant of a general gas pressure actuator determined by the volume of the gas chamber and the compression rate.

JP-A-57-5102 JP-A-8-11078

  In recent years, there has been a significant demand for improved accuracy and resolution in positioning devices. For example, in an exposure apparatus for a semiconductor device, the minimum line width of the semiconductor device is less than 100 nm. Therefore, the dimensional accuracy requirement of the semiconductor device is 10 nm or less, and the positioning accuracy for that purpose is 1 nm or less, that is, sub-nm. Further, the high speed is also required.

  A moving mechanism using a gas actuator is less contaminated as described above than other mechanisms, does not generate electromagnetic noise, and is less affected by temperature changes, vibration, and noise. Therefore, in addition to the use of a positioning actuator such as a semiconductor device, it is expected to be used as an actuator for canceling vibration in a vibration isolation device. However, due to the characteristics that come from the nature of the gas as described above, it is often difficult to achieve the desired high accuracy and high speed response even if sophisticated and complicated control is used.

  Also, an attempt to improve the spring constant using a metal bellows or the like cannot be expected to be too high because the spring constant is determined by the characteristics of the metal material. Further, in the case of directly attaching to the table, the structure for performing two-dimensional movement, such as an XY table, becomes complicated.

  An object of the present invention is to provide a minute moving mechanism capable of improving high-speed response in a moving mechanism using gas. Another object of the present invention is to provide a minute movement mechanism that can improve controllability in a movement mechanism that uses gas. Another object of the present invention is to provide a minute movement mechanism that can improve vibration isolation performance in a movement mechanism that uses gas in a vibration isolation device. The invention according to the following claims contributes to at least one of these objects.

The present invention pays attention to the high spring constant of the gas bearing mechanism, changes the gap of the gas bearing by controlling the gas pressure supplied thereto, and uses this change in the gap for the minute movement of the object. This is to achieve a good micro-movement mechanism. Here, the gas bearing mechanism is a bearing mechanism that generally supports a load such as a stage, which is levitated and supported by an appropriate gas pressure with respect to the base. The gas bearing mechanism has an action to counteract when the gap is narrowed due to the variation of the load due to the general properties of the fluid. For example, if the gap of the gas bearing is about 10 μm and this is changed by 1 μm, a force of about 10 N is required. That is, the spring constant = force / displacement is approximately 10 ⁵ N / cm, which is a significantly larger value than a general piston / cylinder type gas pressure actuator. In addition, the relationship between the clearance of the gas bearing and the supply gas pressure is a simple structure, so it is expected to ride on the theory of compressible gas flow. Is good and does not require complicated control. By controlling the gas pressure of such a gas bearing mechanism, a minute movement can be performed with an accuracy of the order of nm within a range of about several tens of μm. These can be realized without feedback of movement amount measurement, but it is also possible to perform fine movement with higher accuracy by further measuring the movement amount and performing feedback control.

  The minute movement mechanism according to the present invention has a gas receiving surface in a part of the outer shape, a mover used for output, a guide unit that guides the mover and has a gas receiving wall facing the gas receiving surface, and a gas A gas supply path that opens to the receiving surface or the gas receiving wall and supplies gas to the gap between the gas receiving surface and the gas receiving wall, and a pressing force that presses the mover while compressing the gas toward the gas receiving wall And a control unit that controls the gas pressure supplied to the gas supply path and adjusts the gap amount between the gas receiving surface and the gas receiving wall while balancing with the pressing force, and moves the mover slightly. It is characterized by that.

  By the said structure, a gas bearing is formed between the gas receiving surface of a needle | mover, and the gas receiving wall of a guide part, and the gas pressure supplied to the clearance gap is controlled. Therefore, the spring constant relating to the minute movement of the mover is significantly higher than that of a general gas pressure actuator, and the high-speed response is improved.

  Further, in the micro movement mechanism according to the present invention, the mover has a gas receiving surface at both ends in the axial direction of the micro movement, and the guide part has a gas receiving wall corresponding to each gas receiving surface of the mover. The gas supply path supplies a gas to each gap formed between the mover and the guide portion, and a plurality of gases having a force generated in one gap as a pressing force toward the other gap. It is a supply path, and it is preferable that the control unit finely moves the mover by controlling the gas pressure supplied to each gas supply path. According to the above configuration, the pressing force generator is not particularly required, and the configuration is simple.

  In the micro movement mechanism according to the present invention, the axial direction of the micro movement has an X-axis direction and a Y-axis direction orthogonal to each other, and the mover has both ends in the X-axis direction and both ends in the Y-axis direction. Each part preferably has a gas receiving surface. With the above configuration, a so-called XY moving mechanism can be configured.

  In the micro movement mechanism according to the present invention, the axial direction of the micro movement has a Z-axis direction orthogonal to the X-axis direction and the Y-axis direction, and the mover receives gas at one end in the Z-axis direction. It is preferable to have a surface. With the above configuration, a so-called XYZ moving mechanism can be configured.

  Further, the micro movement mechanism according to the present invention connects six micro movement actuators between the base and the movable stage in a predetermined positional relationship, and controls each micro movement actuator to drive the movable stage. A micro-movement mechanism that performs a motion of 6 degrees of freedom with respect to a base, and each micro-movement actuator has a gas receiving surface in a part of the outer shape, guides the mover used for output, and the mover, A guide part having a gas receiving wall facing the gas receiving surface; a gas supply path that opens to the gas receiving surface or the gas receiving wall and supplies gas to a gap between the gas receiving surface and the gas receiving wall; and a gas receiving wall The pressing force generation part that presses the mover while compressing the gas toward the gas and the gas pressure supplied to the gas supply path are controlled, and the amount of the gap between the gas receiving surface and the gas receiving wall is balanced with the pressing force. Adjust and move the mover slightly A control unit that, characterized in that it comprises a. With the above configuration, a so-called 6-degree-of-freedom parallel link mechanism can be configured.

  The micro-movement mechanism according to the present invention is a micro-movement mechanism in which a plurality of movers are arranged in series in the axial direction of the micro movement, and has a gas receiving surface in a part of the outer shape and is used for output. An intermediate mover having gas receiving surfaces at both ends in the axial direction of the micro movement, and a gas receiving wall facing one gas receiving surface of the intermediate mover, the other gas receiving surface of the intermediate mover A guide portion that guides the intermediate mover and the output mover arranged in series so that the gas receiving surface of the output mover faces each other, and opens to the gas receiving surface or the gas receiving wall; A plurality of gas supply paths for supplying gas to the gap between the intermediate mover and the gap between the intermediate mover and the output mover, and the gas in the guide portion while compressing the gas in each gap A pressing force generator for pressing the output mover and the intermediate mover toward the receiving wall; and The gas pressure supplied to the body supply path to control respectively, characterized in that it comprises a control unit for the movable element is finely moved for output by adjusting the gap amount of the gap while balanced with the pressing force. Here, the number of intermediate movers may be plural. Thus, the intermediate mover is arranged between the gas receiving wall of the guide part and the output mover, and these are also moved minutely by the gas bearing mechanism, so that the final output mover with respect to the guide part The range of minute movement can be expanded.

  Further, in the micro movement mechanism according to the present invention, a relative vibration between the installation section where the micro movement mechanism is installed or a mover used for output is detected and the mover used for output is detected. And a vibration sensor for detecting the displacement of the mover, and the control unit further receives a signal indicating the vibration state detected from the vibration sensor and cancels the vibration. Position control means for receiving a signal indicating the displacement state detected from the sensor and canceling the difference from the target position of the mover inputted in advance. With the above configuration, it is possible to suppress the influence of external vibrations on the movable part. By providing such a fine movement mechanism on the stage, a fine movement stage can be configured, and the stage itself can be used as a vibration isolation stage.

  Moreover, it is preferable that the gas supply path has a hollow pocket opening and a throttle portion provided on the upstream side of the pocket opening. By providing the throttle part in the middle of the gas pressure supply path to the gas bearing, the fluid resistance constituting the gas circuit can be increased and stable gas pressure can be supplied.

  Moreover, it is preferable that the throttle portion is a parallel gap throttle that includes a parallel gap having a predetermined interval along the gas flow direction, and that forms the gas flowing through the throttle portion without disturbance by the rectifying action of the parallel gap. Moreover, it is preferable that the throttle part is a porous material throttle that includes a porous material and forms the gas flowing in the throttle part without disturbance by the rectifying action of the porous micropores.

  With the above configuration, the gas flowing through the throttle is formed without any disturbance due to the rectifying action of parallel gaps or micro holes, so that turbulent flow or vortex flow that occurs when the gas is throttled by a typical orifice throttle, for example, is suppressed. Particularly, shock waves generated from the edge of the orifice or the like are suppressed when a high-pressure and high-speed gas is handled. Therefore, in the gas pressure control, the influence of such noise can be reduced, and the controllability of the micro movement mechanism can be improved.

  Moreover, it is preferable that a diaphragm part is any one diaphragm among a self-made diaphragm, a surface diaphragm, a slit diaphragm, or a composite diaphragm. The controllability of the minute movement mechanism can be improved by a simpler throttle unit.

  As described above, according to the micro movement mechanism according to the present invention, high-speed response can be improved in the movement mechanism using gas. Moreover, according to the micro movement mechanism according to the present invention, the controllability can be improved in the movement mechanism using gas. Further, the vibration isolation performance of the vibration isolation device can be improved by using the micro movement mechanism according to the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of the minute movement mechanism 10. The micro-movement mechanism 10 is provided on a movable element 12 that can move in the movement direction indicated by an arrow in FIG. 1, a guide part 14 that guides the movable element 12 in the movement direction, and a bottom surface member 16 of the guide part 14. A gas supply path 18 that supplies gas to a gap between the guide portion 14 and the movable element 12 on the upper surface of 16 and a gas pressure supplied to the gas supply path 18 to control the movable element 12 in the direction of the arrow. And a control unit 20 for performing minute movement.

  The mover 12 is a member having a function as an actuator mover that is connected to a moving object such as a moving table and moves the moving object minutely. For example, a cylindrical metal member or ceramic member can be used. The bottom surface of the mover 12 is a gas receiving surface 22 that receives gas from the gas supply path 18. The gas receiving surface 22 is preferably processed flat. In the example of FIG. 1, since the moving direction indicated by the arrow is the direction of gravity, the mover 12 is pressed against the bottom member 16 of the guide portion 14 by its own weight.

  The guide portion 14 is a member that supports the mover 12 movably along the moving direction, and is a member having a guide hole that is slightly larger than the outer shape of the mover 12. Such a guide portion 14 can be obtained by fitting the bottom member 16 into a metal or ceramic tube. Of course, it can also be manufactured by integral molding.

  The bottom surface member 16 of the guide portion 14 has a gas receiving wall 24 facing the gas receiving surface 22 of the mover 12 on the upper surface thereof, that is, the surface facing the inside of the cylindrical guide of the guide portion 14. The gas receiving wall 24 is preferably machined flat. Assuming that the bottom surface member 16 is an assembly member constituting the guide portion 14, when the movable element 12 is guided by the cylindrical guide of the guide portion 14 and is below the gas receiving surface 22, It is positioned and fixed to the cylindrical guide member of the guide portion 14 so that the gas receiving wall 24 is substantially parallel.

  The inner wall of the guide portion 14 is provided with a ring-shaped groove corresponding to the position of the upper surface where the bottom surface member 16 is fitted, and part of the groove is connected to the outside to become the exhaust port 28. The exhaust port 28 has a function of discharging the gas supplied from the gas supply path 18 and passing through the gap between the gas receiving surface 22 and the gas receiving wall 24 to the outside.

  The gas supply path 18 is a gas passage for supplying a gas from a gas source (not shown) to the gap between the gas receiving surface 22 and the gas receiving wall 24. The pressure of the supplied gas and the like are placed under the control of the control unit 20. The gas supply path 18 has an inlet on the bottom surface side of the bottom surface member 16, that is, the outer bottom surface of the guide portion 14, penetrates the bottom surface member 16 toward the gas receiving wall 24 side, and opens at the gas receiving wall 24. A throttle portion 26 is provided on the upstream side before the opening. Details of the diaphragm 26 will be described later.

  The control unit 20 has a function of adjusting the pressure of a gas from a gas source (not shown) and supplying the pressure to the gas supply path 18. Specifically, a gas pressure corresponding to a desired minute movement amount of the mover 12 is supplied to the gas supply path 18. If a gas is supplied between the gas receiving surface 22 of the mover 12 and the gas receiving wall 24 of the guide portion 14, the supplied gas is subjected to a pressing force that is the weight of the mover 12 according to the pressure. It tries to float the mover 12 against it. As a result of the experiment, the relationship between the supply gas pressure and the flying height, that is, the gap at that time, almost coincides with the calculated value from the flow theory of the compressible gas. For example, when the pressing pressure is 0.4 Mpa and the supply gas pressure is changed to 0.25 to 0.60 MPa, the gap linearly changes to 10 to 20 μm. If the change in the supply gas pressure is small, (gap change amount / gas pressure change amount) becomes a substantially constant value. In this example, for example, (10 μm / 0.35 Mpa) or (10 nm / 0.35 kpa) can be used.

  The control unit 20 includes a command value 30, a subtractor 32, a preamplifier 34 that amplifies the output of the subtractor 32, a current amplifier 36 that amplifies the output of the preamplifier 34 to a drive current level, and an output of the current amplifier 36. A gas pressure valve 38 that adjusts the pressure of a gas from a gas source that is not shown in accordance with the pressure, and a pressure sensor 40 that detects the actual gas pressure in the gas supply path 18 and returns it to the subtractor 32. . As the gas pressure valve 38, a general electronically controlled servo valve or the like can be used. As the pressure sensor 40, a general pressure detecting element capable of outputting an electric signal, an electronic pressure gauge, or the like can be used. Further, the pressure sensor can be omitted. For example, the pressure sensor can be omitted by using a precision pressure control valve or the like that can output a pressure proportional to an electrical signal as the servo valve.

  The operation of this configuration will be described. Initially, the command value 30 is set so as to achieve an initial steady state, that is, a standard flying height. For example, if the pressing pressure corresponding to the dead weight of the mover 12 is 0.1 Mpa, the standard gap is 15 μm, and the control gas pressure at that time is 0.4 MPa, the command value 30 is a value corresponding to P = 0.4 MPa. Is output. The command value 30 may be an analog command value or a digital command value. The command value 30 is converted and amplified into a current that can drive the gas pressure valve 38 via the preamplifier 34 and the current amplifier 36, and the gas pressure valve 38 operates accordingly to adjust the pressure of the gas from a gas source (not shown). The output is set to a predetermined 0.4 MPa.

  The outputted 0.4 MPa is guided to the inlet of the gas supply path 18, passes through the throttle portion 26, and is ejected from the opening provided in the gas receiving wall 24 toward the gas receiving surface 22 of the mover 12. Then, the mover 12 floats from the gas receiving wall 24. The flying gap is 15 μm depending on the setting. This action of forming a gap by floating and supporting the mover 12 with respect to the guide portion 14 is known as a so-called gas bearing mechanism.

  The supplied gas is discharged from the exhaust port 28 through the ring-shaped groove inside the cylindrical guide through the gap while maintaining the floating gap. The exhausted gas can also be returned to a gas source not shown. The gas pressure supplied to the gas supply path 18 is returned to the subtractor 32 by the pressure sensor 40, and when the gas pressure fluctuates due to disturbance or the like, feedback is made so as to make the error zero accordingly.

  Next, a state when an instruction to move the mover 12 upward by 2 μm is issued will be described. At this time, when (gap change amount / gas pressure change amount) = (10 μm / 0.35 Mpa) is used, 0.47 MPa obtained by adding 0.07 Mpa corresponding to 2 μm to the original 0.4 MPa is the command value 30. It becomes. Similarly to the above process, the gas pressure valve 38 adjusts the gas pressure of a gas source (not shown) corresponding to the command, and outputs a gas pressure of 0.47 MPa. This gas pressure is supplied to the gas supply path 18, and is ejected to the gap between the gas receiving surface 22 and the gas receiving wall 24 through the throttle portion 26. The amount of the clearance gap at that time is 17 μm, which is 15 μm to +2 μm, depending on the setting. In this way, the mover 12 is guided by the guide portion 14 in the direction of the arrow in FIG. 1 and moves slightly +2 μm upward.

  That is, in the gas bearing formed between the mover 12 and the guide part 14, the mover 12 can be moved minutely with respect to the guide part 14 by controlling the gas pressure supplied. And the control is sufficient by controlling the gas pressure, and complicated movement such as position control and speed control is not required, and micro movement on the order of μm can be realized. Further, since the spring constant of the gas bearing is high as described above, a high-speed response is possible.

  Here, the diaphragm 26 will be described. The throttle part 26 is an element or a structure having a function of increasing a fluid resistance provided in the middle of the gas pressure supply path to the gas bearing. FIG. 2 shows an example of the configuration of a specific throttle part, and here, a parallel gap throttle 50 provided in the pocket opening 48 is shown. The parallel gap stop 50 includes a ring plate 52 having a central hole in a donut shape and a circular plate 54 having the same outer shape as the ring plate 52 and a narrow parallel gap, and gas flows between the parallel gaps. The flow is rectified and the flow is formed without disturbance. The parallel gap is, for example, a case where the gas pressure supplied to the gas supply path 18 is 0.5 Mpa, the flow rate is 30 m / sec, and the flow rate is 300 m / sec by throttling. preferable. At this time, the length of the parallel gap between the annular plate 52 and the circular plate 54 is desirably sufficiently long with respect to several tens of μm. For example, it can be about 5-10 mm.

  In this way, by forming the gas flowing through the throttle part without turbulence by the rectifying action of the parallel gap throttle, for example, turbulent flow or vortex flow generated when the gas is throttled by an orifice throttle, which will be described later, which is generally used as a throttle Can be suppressed. In particular, it is possible to suppress a shock wave generated from an edge of the orifice or the like when a high-pressure and high-speed gas is handled. Therefore, in the gas pressure control, the influence of such noise can be reduced, and the controllability of the micro movement mechanism can be improved.

  FIG. 3 is a diagram showing an example in which the porous material 56 is disposed in the pocket opening 48 as an example of the throttle portion. Also in this case, the gas flowing in the throttle portion can be formed without disturbance by the rectifying action of the porous micropores.

  FIG. 4 is a diagram showing an example of another throttle section, and FIG. 4A shows a very general orifice throttle 58. (B) is a composite restrictor 60 that narrows the gas supply path 18 and provides a shallow groove in the gas receiving wall 24 radially from the opening toward the outer peripheral side. The depth of the very shallow groove is preferably smaller than the gap between the gas receiving wall 24 and the gas receiving surface 22 and can be, for example, 7 to 20 μm. (C) is a self-contained diaphragm 62 that simply provides a narrow opening. (D) is a slot stop 64 using a thin slot. (E) is a surface diaphragm 66 that does not narrow the gas supply path 18 in the composite diaphragm 60, and simply provides a very shallow groove in the gas receiving wall 24 radially from the opening toward the outer peripheral side.

  Each of these throttle parts is characterized by ease of manufacture, rectification, diaphragm characteristics, and the like. Therefore, it is preferable to select a configuration that is most suitable in terms of cost and performance in consideration of responsiveness, noise resistance, gas conditions, and the like required for the minute movement mechanism 10.

  In the above configuration, the guide unit 14 guides the mover 12 through the cylindrical hole and supports the mover 12 so as to be movable in the minute movement direction. However, the guide unit 14 is provided between the inner wall of the guide unit 14 and the side wall of the mover 12. A gas bearing may be provided. FIG. 5 shows an example of such a configuration. In addition to the configuration of FIG. 1, a bearing air supply port 70 for a radial gas bearing and an exhaust port 72 for discharging the supplied gas are provided.

  Furthermore, a vacuum port 74 may be provided on the opening side of the guide portion 14, that is, on the exit side where the mover 12 moves. In the vacuum port 74, the gas supplied from the gas supply path 18 and the bearing air supply port 70 is not collected from the exhaust ports 28 and 72, and a gap between the inner wall of the guide portion 14 and the outer periphery of the mover 12 is formed. It has a function to prevent leaking outside. By providing the vacuum port 74, the micro movement mechanism 10 can be used even in a vacuum atmosphere.

  In the above configuration, the pressing force between the gas receiving surface 22 and the gas receiving wall 24 is based on the weight of the mover 12, but apart from this, an appropriate pressure is applied to the mover 12 to generate a pressing force. It is good also as what to do. FIG. 6 is a diagram showing an example of such a configuration. The movable element 12 has a stepped structure, and a pressurizing port 76 for supplying a pressurized gas having a constant pressure to the stepped portion is provided. In addition, an exhaust port 78 for discharging the gas supplied from the pressurizing port 76 is provided. In FIG. 6, a bearing air supply port 70 for a radial gas bearing and an exhaust port 72 for discharging the supplied gas are provided as in FIG. 5, and the vacuum port 80 is provided in one place. It is done. In this way, by generating the pressing force independently of the dead weight of the mover 12, it is possible to use the minute movement mechanism independently in a horizontal position.

  In addition, the gas supplied from the gas supply path 18 passes through a ring-shaped groove provided on the inner wall of the guide portion 14 and is discharged from the exhaust port 28. However, the gas can be discharged from the bottom member 16 side. . FIGS. 7A and 7B show examples of such a configuration, in which FIG. 7A is a top view of the bottom member 16, and FIG. 7B is a side sectional view showing the relationship between the bottom member 16 and the mover 12. The bottom member 16 is provided with an exhaust groove 82 in a ring shape, and the gas supplied from the gas supply path 18 is collected in the exhaust groove 82 and discharged to the outside through the exhaust port 84. Alternatively, a ring-shaped vacuuming groove 86 may be provided outside the exhaust groove 82, and a gas that cannot be exhausted from the exhaust port 84 may be recovered using the vacuum port 88.

  The mover and guide part of the micro-movement mechanism are made into one set, and two sets are used so as to face each other, so that the pressing force generation mechanism can be omitted, and the entire structure is close to non-reaction. be able to. FIG. 8 is a diagram illustrating a configuration of the minute moving mechanism 100 using two sets of the movable element 12 and the guide unit 14 having the configuration described in FIG. Elements similar to those in the drawings of FIG. 1 and subsequent drawings are denoted by the same reference numerals, and detailed description thereof is omitted. The micro-movement mechanism 100 includes a movable element 12 and a guide unit 14 similar to those shown in FIG. 5 as a set on a base 102, which are arranged on a straight line so as to face each other, and between the two movable elements 12. The slider 104 is arranged so as to be sandwiched therebetween. The slider 104 is provided with a support member 106 that supports a bearing with the base 102. A gas pressure controlled by a separate control unit 20 is supplied to the gas supply path 18 of each bottom member 16.

  In the above configuration, for example, if the gas pressure supplied to the gas supply passage 18 in the left set is larger than the gas pressure supplied to the gas supply passage 18 in the right set, the slider 104 faces right in the direction of the arrow shown in FIG. Displaces in the direction of. The magnitude of the displacement is the difference between the gap amount corresponding to the gas pressure supplied to the left set gas supply passage 18 and the gap amount corresponding to the gas pressure supplied to the right set gas supply passage 18. become.

  In this configuration, since the amount of displacement is a difference, finer movement can be performed compared to the movement mechanism 10 shown in FIG. Similarly, the force received by the slider 104 from each movable element 12 is subtracted, and the movement is performed with a small force as a whole, and an operation close to non-reaction can be achieved. Further, since the movable element 12 is disposed on both sides of the slider 104, the force generated by one movable element 12 works to press the other movable element toward the guide portion. Therefore, a special pressing force generating mechanism is not required even though the minute moving mechanism is placed horizontally and the pressing force due to gravity is not used.

  FIG. 9 is a diagram illustrating an example of a configuration in which the mover in FIG. 8 is omitted, and the gas receiving wall 24 of the bottom surface member 16 is directly opposed to the receiving surface 108 of the slider 104. In this configuration, a gas bearing mechanism is formed between the gas receiving wall 24 and the receiving surface 108, and the gap therebetween can be controlled by the gas pressure supplied to the gas supply path 18 to move the slider 104 minutely. .

  By arranging the gas bearing gap adjustment mechanism formed by the gas receiving surface of the mover and the gas receiving wall of the guide portion as one set, so as to operate in the X axis direction and the Y axis direction, respectively. An XY minute movement mechanism can be configured. In addition, an XYZ minute movement mechanism can be configured by adding a set that operates in the Z-axis direction.

  10 and 11 are diagrams showing the configuration of the XYZ minute movement mechanism 120 excluding the control unit, FIG. 10 is a plan view, and FIG. 11 is a cross-sectional view taken along the line AA in FIG. The XY minute moving mechanism 120 includes a rectangular stage 122 and a casing 124 that supports the stage 122 so as to be movable in the XYZ directions. Between the stage 122 and the housing 124, there are four sets of gas bearing gap adjusting mechanisms 126 for minute movement in the X-axis direction shown in FIGS. 10 and 11, and gas bearing gaps for minute movement in the Y-axis direction. Four sets of adjustment mechanisms 128 and four sets of gas bearing gap adjustment mechanisms 130 for minute movement in the Z-axis direction are arranged. In each gas bearing gap adjusting mechanism, the gas supply path 18 is provided on the casing 124 side, and gas for forming a gap is ejected toward the stage 122 side. The mechanism for adjusting the gap is the same as that described with reference to FIG.

  By adjusting the gas pressure supplied to the total 12 gas supply paths 18 with the configurations of FIGS. 10 and 11, the stage 122 can take any XYZ position within the range of guidance of the casing 124. Can do. The operation can be easily understood by breaking it down into an operation in the X-axis direction, an operation in the Y-axis direction, and an operation in the Z-axis direction. For example, regarding the operation in the X-axis direction, only the operation of the four gas bearing gap adjustment mechanisms 126 need be considered. To make it simpler, divide the four sets into two sets on the left half and two sets on the right half. The two sets on the left half perform the same operation and the two sets on the right half perform the same operation. Think about it. The operation in this case is the same as the operation of the configuration of FIG. 9 in which there are bottom surface members facing each other in the X-axis direction and the slider is disposed between them, and minute movement in the X-axis direction can be controlled. Similarly, four sets of gas bearing clearance adjustment mechanisms 128 can control minute movements in the Y-axis direction by assuming that the two sets of the upper half and the two sets of the lower half perform the same operation, and the four sets of gas bearing clearance adjustment mechanisms. It is possible to control the minute movement in the Z-axis direction assuming that all of 130 perform the same operation. In this way, an XYZ moving mechanism can be configured.

  Further, among the four sets of the gas bearing clearance adjustment mechanisms 126, the upper right one and the lower left one are set as a pair, the lower right one and the upper left one are set as different sets, and the movement amount of each set is made different. Thus, the stage 122 can be rotated around the Z axis. Four sets of gas bearing gap adjustment mechanisms 128 may be used. Similarly, the stage 122 around the X axis can be rotated by changing the movement amount of the two sets of the upper half and the two sets of the lower half of the four sets of the gas bearing gap adjusting mechanisms 130. The stage 122 around the Y axis can be rotated by changing the amount of movement of the two sets of the right half and the two sets of the left half of the set of gas bearing gap adjusting mechanisms 130. In this way, the stage 122 can be finely moved with six degrees of freedom.

  Note that these gas bearing gap adjusting mechanisms 126, 128, and 130 do not have to be four each, and each or any one of them may be configured by a number other than four. Further, it is not necessary to arrange them symmetrically, and an appropriate arrangement can be taken according to the shape of the stage 122, the required performance, and the like. In addition, for example, the number of arrangements on the left and right sides may be different, such as one on one side and two on the other side, instead of two each on the left and right sides in the X-axis direction. Similarly, the number of arrangements around the Y-axis direction and the Z-axis may be asymmetric.

  FIG. 12 is a diagram illustrating a configuration when a mechanism 132 that generates a pressing force for pressing the stage 122 toward the bottom surface of the casing 124 is added. Since the stage 122 has its own weight, it generates an appropriate pressing force toward the bottom surface of the casing 124. However, when an appropriate pressing force is desired for better control of minute movement, etc. There is. In FIG. 12, a mechanism 132 that generates a pressing force is supplied with a constant pressurized gas from the pressure port 76 so as to apply a downward force to the upper surface side of the stage 122.

  FIG. 13 is a diagram illustrating an example in which a force that attracts the stage 122 toward the bottom surface of the casing 124 is generated by another mechanism. In FIG. 13, a yoke 134 is provided on the bottom surface side of the stage 122, and a yoke 136 and a magnet 138 are provided on the bottom surface upper surface side of the casing 124 corresponding thereto. The stage 122 is attracted toward the bottom surface of the casing 124 by a magnetic circuit formed by the yokes 134 and 136 and the magnet 138. This attractive force is equivalent to the above-mentioned pressing force. An appropriate pressing force can be generated using the mechanism shown in FIGS.

  14 and 15 show the arrangement of an exhaust groove 140 and an exhaust port 142 for exhausting gas from the gas supply path 18, and an evacuation groove 144 and a vacuum port 146 for collecting gas that cannot be exhausted. FIG. FIG. 14 is a cross-sectional view of the XYZ minute moving mechanism 120, and FIG. 15 is a view showing the inner wall of the casing 124 when viewed along the line BB in FIG. As described above, the exhaust groove 140 and the vacuuming groove 144 are arranged around the inner wall of the housing 124 while being separated from each other. The arrangement of the exhaust grooves and the vacuum grooves for the gas supply path 18 on the bottom surface of the casing 124 can be the same as that described in FIG. 7, for example.

  FIG. 16 is a diagram illustrating an example in which the six-degree-of-freedom parallel link mechanism 150 is configured using six minute movement mechanisms. The 6-degree-of-freedom parallel link mechanism 150 is configured by attaching six minute movement mechanisms 160 between the base 152 and the movable stage 154 at a predetermined angular arrangement. This configuration is obtained by replacing the six actuators of the configuration in a general six-degree-of-freedom parallel link with a micro-movement mechanism 160, and by controlling the amount of displacement of each of the six micro-movement mechanisms 160 by a known control method. The movable stage 154 can be moved with respect to the base 152 with six degrees of freedom of X, Y, Z, φ, θ, and ψ.

  FIG. 17 is a diagram showing a configuration around the minute movement mechanism 160. Since the minute movement mechanism 160 having the same configuration as that described with reference to FIG. 6 can be used, the same elements are denoted by the same reference numerals, and detailed description thereof is omitted. One end of a base side flexible joint 162 is attached to the bottom surface member 16 of the minute movement mechanism 160, and the other end of the base side flexible joint 162 is attached to a predetermined position of the base 152. Further, one end of a movable stage side flexible joint 164 is attached to the movable element 12, and the other end of the movable stage side flexible joint 164 is attached to a predetermined position of the movable stage 154.

  The control unit of each minute movement mechanism 160 is attached to each bottom surface member 16. In FIG. 17, a control valve 166 and a circuit block 172 indicate the control unit. The control valve 166 includes a supply port 168 to which gas is supplied from a gas source (not shown), and used gas to the outside. An exhaust port 170 for discharging is shown.

  The micro movement mechanism can move on the order of μm, but the micro movement range can be expanded by connecting a plurality of micro movement mechanisms in series. Specifically, an intermediate mover having gas receiving surfaces at both ends in the axial direction of minute movement is used. The standard mover as described in FIG. 1 is referred to as an output mover. The output mover-intermediate mover-intermediate mover --- intermediate mover-guide unit. As in the case of “gas receiving wall”, an intermediate mover may be added and arranged in series according to the required minute movement range.

  FIG. 18 is a diagram showing an example in which three intermediate movers 200 that provide openings on one side at both end portions in the axial direction of minute movement and supply gas pressure controlled by the gas supply path 18 toward the openings are shown. It is. Elements similar to those used in FIG. 1 and subsequent drawings are given the same reference numerals, and detailed description thereof is omitted. Further, each port provided in the guide unit 14 is given a symbol indicating its function. CP is a supply of gap control gas pressure, EX is exhaust, SB is a supply of bearing gas for supporting the intermediate mover 200 or the output mover 12, CP2 is a supply of pressing force generating gas, VP indicates evacuation.

  In the configuration of FIG. 18, the rightmost intermediate movable element 200 moves by a predetermined minute amount due to the gas pressure from the gas supply path 18 in the bottom member 16, and in this state, from the gas supply path 18 in the rightmost intermediate movable element 200. The next intermediate mover 200 moves by a predetermined minute amount due to the gas pressure, and this is repeated, and the output mover 12 becomes predetermined by the gas pressure from the gas supply path 18 in the leftmost intermediate mover 200. Move a little. Therefore, the minute movement amount of the output movable element 12 relative to the guide portion 14 is the sum of the movement amounts of the intermediate movable elements 200, and the minute movement range is expanded. Also, the directions of the minute movement amounts can be opposite to each other. In this case, the movement amount can be subtracted and the minute movement amount can be reduced.

  A modification of FIG. 18 is shown in FIGS. In FIG. 19, the intermediate mover 200 adjacent to the output mover 12 uses the same intermediate mover 200 as in FIG. 18, and other than that, the gas pressure from the gas supply path 18 of the bottom surface member 16 is directly used as the next mover. An intermediate mover 210 having a gas passage 208 therethrough is used to communicate. The intermediate mover 210 receives a gas pressure from one end side thereof, blows out at the other end side, and forms a gas bearing mechanism with a surface on one end side of the next mover. That is, the intermediate mover 210 has the self-formed aperture described with reference to FIG. That is, it is the same as in FIG. 18 that has gas receiving surfaces at both ends in the axial direction of the minute movement and forms a gas bearing mechanism at each interface. The surface diaphragm described with reference to FIG. 4 can be used instead of the self-formed diaphragm. Therefore, in this case, although the configuration is simplified, the minute movement amount of the output movable element 12 with respect to the guide unit 14 is the sum of the respective movement amounts of the intermediate movable element 200, which also enlarges the minute movement range or Can be reduced.

  FIG. 20 is a diagram illustrating an example in which all the intermediate movers are the intermediate movers 210 described in FIG. In this case, the configuration can be further simplified and the range of the minute movement amount of the output movable element 12 relative to the guide portion 14 can be expanded.

  In addition to being used for moving a minute distance, such as a positioning actuator, the minute moving mechanism can be used for a minute moving mechanism for canceling vibration in a vibration isolation device. FIG. 21 is a diagram illustrating a configuration of a minute movement mechanism used in the vibration isolation device. The guide unit 14 is placed on an installation table 220 on which a minute movement mechanism is installed. The mover 12 corresponds to a vibration isolation table. In an environment where external vibration D is applied to the mover 12, a vibration sensor 222 for detecting the vibration is attached to the mover 12. On the other hand, in an environment where external vibration D is applied to the installation table 220, it is preferable to attach the vibration sensor 222 to the installation table 220. As the vibration sensor 222, for example, an acceleration sensor such as a piezoelectric element can be used. In addition, a displacement sensor 224 for detecting the displacement of the mover 12 is provided. As the displacement sensor, for example, a commercially available displacement sensor such as a non-contact optical displacement sensor or a contact mechanical sensor can be used.

  The detection signal from the vibration sensor 222 and the detection signal from the displacement sensor 224 are input to the control unit 226. In addition to the functions described with reference to FIG. 1, the control unit 226 controls the gas pressure to the gas supply path 18 so as to cancel this vibration in response to a signal indicating the vibration state detected from the vibration sensor 222. Has anti-vibration control function. Further, a position control function for controlling the gas pressure to the gas supply path 18 so as to cancel the difference from the target position of the mover input in advance in accordance with a signal indicating the displacement state detected from the displacement sensor 224. Have The vibration isolation control function and the position control function can be performed using a general target value control technique. Depending on the required specifications of the vibration isolator, the displacement sensor 224 may be omitted.

  Thus, based on the uniaxial micro movement mechanism described in FIG. 1, the XY movement mechanism, XYZ movement mechanism, 6-degree-of-freedom movement mechanism described in FIG. 10, the 6-degree-of-freedom parallel link mechanism described in FIG. It can be developed to the movement amount enlargement mechanism of FIG. 18-20, the vibration isolation mechanism described in FIG. Although the mechanisms of these development systems have been described individually for convenience of explanation, these development systems can also be configured independently, and may be configured by an appropriate combination among them. For example, the movement amount expansion mechanism may be combined with an XY movement mechanism, an XYZ movement mechanism, a 6-degree-of-freedom movement mechanism, a 6-degree-of-freedom parallel link mechanism, and a vibration isolation mechanism. Further, the vibration isolation mechanism can hate the XY movement mechanism, the XYZ movement mechanism, the 6-degree-of-freedom movement mechanism, and the 6-degree-of-freedom parallel link mechanism. Further, another development system mechanism may be combined with the combination of the movement amount expansion mechanism and the vibration isolation mechanism.

It is a block diagram of the micro movement mechanism in embodiment which concerns on this invention. It is a figure which shows a parallel gap aperture stop as an example of the aperture | diaphragm | squeeze part of the micro movement mechanism in embodiment which concerns on this invention. It is a figure which shows a porous material as an example of the aperture | diaphragm | squeeze part of the micro movement mechanism in embodiment which concerns on this invention. It is a figure which shows the example of the other aperture part of the micro movement mechanism in embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a figure which shows a mode that a gas bearing is provided in the inner wall of the guide part of a micro movement mechanism. In embodiment which concerns on this invention, it is a figure which shows a mode that the pressurization port which generate | occur | produces pressing force is provided in the needle | mover of a micro movement mechanism. In embodiment which concerns on this invention, it is a figure which shows a mode that exhaust_gas | exhaustion is performed from the bottom face member side of a micro movement mechanism. In embodiment which concerns on this invention, it is a figure which shows the structure of the micro moving mechanism which uses 2 sets of needle | movers and a guide part. It is a figure which shows the modification of FIG. It is a top view of the XYZ minute movement mechanism in an embodiment concerning the present invention. It is sectional drawing in the AA line of FIG. It is a figure which shows a mode that the mechanism which generate | occur | produces the pressing force of the stage of the XYZ micro movement mechanism in embodiment which concerns on this invention toward the bottom face of a housing | casing is added. It is a figure which shows the example which produces | generates the force which attracts the stage of the XYZ micro movement mechanism in embodiment which concerns on this invention toward the bottom face of a housing | casing. It is sectional drawing which shows the mode of exhaust_gas | exhaustion of the XYZ micro movement mechanism in embodiment which concerns on this invention, and evacuation. It is a figure which shows the inner wall of a housing | casing when it sees along BB line of FIG. In embodiment which concerns on this invention, it is a figure which shows the example which comprises a 6 degree-of-freedom parallel link mechanism using six micro movement mechanisms. It is a figure which shows the structure of each micro movement mechanism used for FIG. In embodiment which concerns on this invention, it is a figure which shows the example using an intermediate needle | mover. In embodiment which concerns on this invention, it is a figure which shows the other example using an intermediate needle | mover. In embodiment which concerns on this invention, it is a figure which shows the other example using an intermediate needle | mover. In embodiment which concerns on this invention, it is a figure which shows the structure of the micro movement mechanism applied to a vibration isolator.

Explanation of symbols

  10, 100, 120, 160 Minute moving mechanism, 12 Movable element, 14 Guide part, 16 Bottom member, 18 Gas supply path, 20, 226 Control part, 22 Gas receiving surface, 24 Gas receiving wall, 26 Restricted part, 28, 72, 78, 84, 142 Exhaust port, 30 command value, 32 subtractor, 34 preamplifier, 36 current amplifier, 38 gas pressure valve, 40 pressure sensor, 48 pocket opening, 52 annular plate, 54 disc, 56 porous material , 58 Orifice restriction, 60 Combined restriction, 62 Self-contained restriction, 64 Slot restriction, 66 Surface restriction, 70 Bearing air inlet, 74, 80, 88, 146 Vacuum opening, 76 Pressure opening, 82,140 Exhaust groove, 86, 144 Vacuum evacuation groove, 102, 152 base, 104 slider, 106 support member, 108 receiving surface, 122 stage, 124 housing, 1 26, 128, 130 Gas bearing clearance adjustment mechanism, 132 pressing force generation mechanism, 134, 136 yoke, 138 magnet, 150 6-degree-of-freedom parallel link mechanism, 154 movable stage, 162 base side flexible joint, 164 movable stage side flexibility Joint, 166 Control valve, 168 Supply port, 170 Exhaust port, 172 Circuit block, 200, 210 Intermediate mover, 208 Gas passage, 220 Installation base, 222 Vibration sensor, 224 Displacement sensor, CP Supply of gas pressure for clearance control, EX Exhaust, SB Supply of bearing gas to support the mover, CP2 Supply of pressing force generation gas, VP vacuuming.

Claims (11)

A mover having a gas receiving surface in a part of the outer shape and used for output;
A guide unit that guides the mover and has a gas receiving wall facing the gas receiving surface;
A gas supply path that opens to a gas receiving surface or a gas receiving wall and supplies gas to a gap between the gas receiving surface and the gas receiving wall;
A pressing force generator that presses the mover while compressing the gas toward the gas receiving wall;
A control unit that controls the gas pressure supplied to the gas supply path, adjusts the gap amount between the gas receiving surface and the gas receiving wall while balancing with the pressing force, and moves the mover minutely;
A micro-movement mechanism comprising: The micro movement mechanism according to claim 1,
The mover has gas receiving surfaces at both ends in the axial direction of micro movement,
The guide unit has gas receiving walls corresponding to the respective gas receiving surfaces of the mover,
The gas supply path is a plurality of gas supply paths that supply gas to each gap formed between the mover and the guide portion, and use the force generated in one gap as a pressing force toward the other gap. ,
The control unit controls the gas pressure supplied to each gas supply path to move the mover minutely. The micro movement mechanism according to claim 2,
The axial direction of the minute movement has an X-axis direction and a Y-axis direction orthogonal to each other,
The mover has a gas receiving surface at both ends in the X-axis direction and both ends in the Y-axis direction. The micro movement mechanism according to claim 3, further comprising:
The axial direction of the minute movement has a Z-axis direction orthogonal to the X-axis direction and the Y-axis direction,
The mover has a gas receiving surface at one end in the Z-axis direction. Six micro-movement actuators are connected between the base and the movable stage in a predetermined positional relationship, and each micro-movement actuator is controlled and driven to cause the movable stage to move with respect to the base with six degrees of freedom. A micro-movement mechanism,
Each micro-movement actuator
A mover having a gas receiving surface in a part of the outer shape and used for output;
A guide unit that guides the mover and has a gas receiving wall facing the gas receiving surface;
A gas supply path that opens to a gas receiving surface or a gas receiving wall and supplies gas to a gap between the gas receiving surface and the gas receiving wall;
A pressing force generator that presses the mover while compressing the gas toward the gas receiving wall;
A control unit that controls the gas pressure supplied to the gas supply path, adjusts the gap amount between the gas receiving surface and the gas receiving wall while balancing with the pressing force, and moves the mover minutely;
A micro-movement mechanism comprising: A micro movement mechanism in which a plurality of movers are arranged in series in the axial direction of micro movement,
A mover having a gas receiving surface in a part of the outer shape and used for output;
An intermediate mover having gas receiving surfaces at both ends in the axial direction of micro movement;
The intermediate mover and the output mover have a gas receiving wall facing one gas receiving surface of the intermediate mover, and the gas receiving surface of the output mover faces the other gas receiving surface of the intermediate mover. A guide unit for arranging and guiding the children in series;
A plurality of gas supply passages that open to the gas receiving surface or the gas receiving wall and supply gas to the gap between the guide portion and the intermediate mover and the gap between the intermediate mover and the output mover, respectively. ,
While compressing the gas in each gap, a pressing force generator that presses the output mover and the intermediate mover toward the gas receiving wall of the guide,
A control unit that controls the gas pressure supplied to each gas supply path, adjusts the gap amount of each gap while balancing with the pressing force, and moves the mover for output minutely,
A micro-movement mechanism comprising: In the micro movement mechanism of any one of Claim 1 or Claim 5 or Claim 6,
A vibration sensor that is provided on an installation part where a micro-movement mechanism is installed or a mover used for output, and detects relative vibration between the installation part and the mover used for output;
A displacement sensor for detecting the displacement of the mover;
With
The control unit
A vibration isolation control means for receiving a signal indicating a vibration state detected from the vibration sensor and canceling the vibration;
Position control means for receiving a signal indicating the displacement state detected from the displacement sensor and canceling the difference from the target position of the mover inputted in advance;
A micro-movement mechanism characterized by comprising: In the micro movement mechanism according to claim 1 or 5,
The gas supply path has a hollow pocket opening and a throttle provided on the upstream side of the pocket opening. The micro movement mechanism according to claim 8, wherein
A micro-movement mechanism characterized in that the throttle part is a parallel gap throttle that includes a parallel gap having a predetermined interval along the gas flow direction and forms the gas flowing through the throttle part without any disturbance by the rectifying action of the parallel gap. The micro movement mechanism according to claim 8, wherein
The throttle unit includes a porous material, and is a porous material throttle that forms a gas flowing in the throttle unit without disturbance by a rectifying action of porous micropores. In the micro movement mechanism according to claim 1 or 5,
The micro-movement mechanism characterized in that the aperture section is any one of a self-made aperture, a surface aperture, a slit aperture, or a composite aperture.

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