JPH10318728A - Three-dimensional shape measuring apparatus and z-axis stage in three-dimensional shape measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cancel abbe's measurement errors generated by posture defect by mounting probe for measurement and a laser interference device for the measurement of the movement amount of every axis on a Z-axis table, as that a measuring point may be situated in the point of intersection of respective optical axes of the laser interference device even when the three-axis mechanism of a shape measuring machine is moved. SOLUTION: A three-dimensional shape measuring apparatus is provided with an X-axis stage 3 and a Y-axis stage 4 which are moved inside a horizontal plane on a surface plate 1, with a Z-axis stage 6 which is erected and installed on them and with a gravity compensation spring 19 which compensates the weight of the stages. A uniaxial air slide 7 as a guide shaft is attached to a Z-axis scale 5. A voice coil motor 8 is used as a driving force which moves the guide shaft. A Z-axis table on which a probe 10 and a laser interference device 13 for the measurement of the movement amount of every axis are mounted can be moved to the Z-axis direction. In order to move the Z-axis table with good accuracy, a linear-scale detecting head is installed at the Z-axis scale 5, and a linear-scale lattice part is installed on the side face of the air slide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional shape measuring apparatus and a Z-axis stage for measuring a three-dimensional shape of an object to be measured in a non-contact manner with high accuracy. It can also be applied to automatic production equipment and precision processing machines.

[0002]

[Prior art]

(1) The invention described in Japanese Patent Application Laid-Open No. 4-299206 (ultra-high-precision three-dimensional measuring machine) is disclosed in which an X-axis direction or an X-
A gantry that moves horizontally in the Y-axis direction is provided, and a Z-axis movement table that moves vertically in the Z-axis direction perpendicular to the X-axis direction or the XY axis direction is provided on the gantry. Measuring means for measuring a distance Z1 between a surface to be measured of a measurement object and a specific point on a Z-axis moving table located above the measuring object is provided, and a support fixed on the surface plate is provided with X perpendicular to the Z-axis. A measuring means for measuring a distance Z2 between the XY axis reference plane and a specific point on the Z axis slide located below the XY axis reference plane; The shape of the object to be measured is measured based on the data of the distance Z1 and the distance Z2 with respect to each measurement point in the XY axis direction of the object to be measured, and a support fixed on a surface plate is provided. By providing an XY reference plane perpendicular to the Z-axis above the Z-axis moving table, A mount and a scale setting means for measurement on the mount while securing a large movable object in the X-Y-Z-axis direction with the Z-axis movable table provided with the measuring means Z1 fixed to the large object to be measured; The arrangement of the measuring means and the optical system such as various mirrors, prisms and polarizers is made compact so that the gantry and the optical system are free from bending and vibration, and the light is directed perpendicularly onto the XY axis reference plane mirror. I have to. (2) JP-A-2-134506 (shape measuring device)
The invention described in (1) is characterized in that a Z-moving unit suspended by a spring and provided with driving means in the vertical direction, and a displacement of the position of the Z-moving unit from an equilibrium position where the tension of the spring and the gravity of the Z-moving unit balance. Position detecting means for detecting and generating a position signal;
A spring force compensating unit that transmits the position signal to the driving unit and generates a driving force having a magnitude substantially equal to and opposite to the direction of the spring force generated in proportion to the displacement from the equilibrium position by the driving unit. In a three-dimensional measuring machine that measures the shape of the surface, the laser light is focused on the measurement surface, focus servo is applied from this reflection surface, and the shape of the measurement surface is measured with ultra-high accuracy of the order of 0.01 μm A method in which the Z moving unit is suspended by a spring and driven by a linear motor with an optical probe or the like, which substantially eliminates the influence of the restoring force of the spring, eliminates focus errors and the like, and achieves high measurement accuracy and good operability. Like that.

[0003]

However, the above-mentioned Japanese Patent Application Laid-Open No.
The invention described in Japanese Patent Application Publication No.-299206 (ultra-high-precision three-dimensional measuring machine) has no measurement point at the intersection of the three orthogonal optical axes of the laser interferometer for measuring the amount of movement of each axis of the measurement system. There is a drawback that Abbe's error caused by the measurement optical layout is included in the data. Since there is no gravity compensation mechanism, the drive motor requires a large thrust, and has a disadvantage that the device becomes large. Since the amount of movement of the Z-axis stage is measured only by the laser interferometer, there is a disadvantage that in a situation where the laser power drops instantaneously, all the position information is lost, which is very dangerous in control. The space occupied by the optical layout is large, and the reference mirror is arranged between the movable table and the measuring head. When measuring a large workpiece, there is a disadvantage that the measuring stroke is limited. This technical problem does not occur because the described linear scale is not used. Does not have a fall prevention mechanism. This technical problem does not occur because a gravity compensation function such as that described above is not used. Does not have a damper function. For this reason, rapid movement is inevitable.

In the invention described in Japanese Patent Application Laid-Open No. 2-134506 (shape measuring device), a coil spring is used as a gravity compensating mechanism. Power)
+ (Spring restoring force) requires a combined thrust. If the spring constant is large, the restoring force of the spring is large and a large motor is required. A spring with a small spring constant requires a certain spring length. In any case, there is a disadvantage that the space of the device is increased. There is no description about replacement of the spring, which does not have a fall prevention function.However, if the spring is simply hooked on a movable body with a hook, there will be play at the joint, which will cause slight vibration. In addition, if the unit is not formed as a unit, it takes a long time to perform the replacement, and a force for supporting a heavy object is required during the replacement.

According to the first aspect of the present invention, the point of intersection of the optical axis of a laser beam for measuring the shape of an object to be measured is set as a measurement point of the object to be measured, thereby eliminating Abbe measurement errors. ) Can be solved.
According to the second aspect of the present invention, the probe is oriented in the direction of gravity, and the measurement is performed in the direction of gravity, so that no tilt is caused by gravity at the time of measurement, and it is not necessary to control the tilt of the probe, thereby simplifying the control of the apparatus. It is made possible.

According to a third aspect of the present invention, two axes of the moving axes are provided on a horizontal plane, and the two axes are moved on the respective axes.
This allows the control to be simplified without being affected by changes in gravity. According to a fourth aspect of the present invention, the movement axis and the axis of the laser beam do not lie on the same straight line, so that interference with the reference mirror is not restricted within a stroke, thereby reducing the size of the entire apparatus. It is made possible.

According to a fifth aspect of the present invention, the plane formed by the two moving axes and the moving axis in the displacement measuring direction are orthogonal to each other so that the control of the moving axis can be simplified. According to a sixth aspect of the present invention, the two axes of the laser beam forming a plane parallel to the plane formed by the two moving axes are orthogonal to each other so that the measurement of the object to be measured and the control of the moving axis can be simplified. is there.

According to a seventh aspect of the present invention, measurement of an object to be measured and control of the movement axis can be easily performed by making the three axes of movement and the three axes of laser light orthogonal to each other.
The invention according to claim 8 is characterized in that the measuring probe and the laser interferometer for measuring the amount of movement of each axis are mounted on the Z-axis table, so that the three-axis mechanism of the shape measuring machine moves no matter how the laser interferometer moves. The prior art (1) can be arranged such that the measurement point is located at the intersection of the optical axes, and can cancel the Abbe measurement error generated due to the straightness of the mechanical system and the poor posture.
It is possible to solve the technical problem of the above.

According to a ninth aspect of the present invention, the magnitude of the restoring force generated even when the spiral spring used in the gravity compensating means is expanded or contracted within a set stroke is hardly changed, and the Z-axis stage is held. This eliminates the necessity of using a large amount of driving force required to perform the operation, and eliminates the need to increase the size of the motor, thereby solving the technical problem of the prior art (1). Also, by directly lifting the load,
An element for transmitting the holding force is not required, so that the rigidity due to the transmitting element does not decrease, and the rigidity can be increased.

When the value of the laser interferometer for measuring the moving amount is used as the feedback value when controlling the Z-axis stage, there is a problem that high-speed control cannot be performed due to the data conversion time. Therefore, when the control is applied, the value of the laser interferometer is not used as the position information,
In the invention of No. 0, stable control can be performed at high speed by using the value of the linear scale.

According to an eleventh aspect of the present invention, a complex optical system is formed by mounting a laser interferometer for measuring the amount of movement of each axis on the front and both sides of an air slide serving as a guide for the Z-axis stage. Therefore, a very compact configuration can be obtained, and interference with a reference mirror fixed on another surface plate is not restricted within the stroke.

If the rigidity of the bobbin structural member of the voice coil motor is low, the rigidity of this portion becomes the lowest in the mechanical system including the Z-axis stage, and the problem remains that the control band cannot be increased. Therefore, according to a twelfth aspect of the present invention, the bobbin structural member is made of a conventional four-piece assembly structure consisting of two pieces each of aluminum and an insulator (for example, a glass epoxy material), and is formed into an integral structure of stainless steel. In order to solve the above problem by increasing the rigidity.

A fall prevention means according to the invention of claim 13 is a stainless steel attached to a side surface of the air slide, between a scissor plate operated by an air cylinder fixed to the back surface of the Z-axis scale and a pad for stopping. The sliding plate of
Sliding while maintaining a very small clearance with the pad, in the form of pressing the sliding plate against the pad with the scissor plate at the time of brake differential, to stop the whole,
At this time, a rubber material having a very high coefficient of friction with stainless steel is adhered to a side of the pad surface that sandwiches the sliding plate, and is attached to the Z-axis table and an air slide that guides the Z-axis table. It is intended to prevent various expensive optical systems from being damaged in an unexpected situation.

[0014] According to the fourteenth aspect of the invention, the time and force required for the operation can be reduced by unitizing the gravity compensating mechanism which needs to be replaced according to the service life. It is designed to be able to be improved. According to a fifteenth aspect of the present invention, the minimum natural frequency (for example, 200 Hz) of the mechanical system including the other Z-axis stages is vertically increased by a slight restoring force generated by the spiral spring used in the gravity compensation means. A much lower natural frequency (eg, 1 Hz) also results. For this reason,
With this mechanism alone, there is a problem that the gain cannot be increased in control because the viscous damping ratio is small.

Therefore, by using a damper utilizing the viscous resistance of a fluid or the like, the viscous damping ratio can be increased, and the viscous damping ratio can be increased at the natural frequency caused by the gravity compensation mechanism of the Z-axis stage. Can be suppressed,
The control allows the gain to be increased.

[0016]

According to the first aspect of the present invention,
In order to achieve the above object, a displacement measuring probe mounted on a surface plate for measuring the shape of an object to be measured is mounted, and moving means for moving the probe in a three-dimensional direction with respect to the object to be measured; Measuring means for measuring the amount of movement of the means, and laser light irradiating means for irradiating the object to be measured with laser light from within the displacement measuring probe, and irradiating the object to be measured with laser light from the laser light irradiating means Then, based on the laser light reflected from the measured object, the moving means moves so as to keep the distance between the measured object and the probe constant, and the measuring means measures the moving amount of the moving means. In the three-dimensional shape measuring apparatus for measuring the shape of the object to be measured by doing, the measuring means, using a three-axis laser length measuring device not coplanar, to measure the amount of movement by the moving means, Laser measurement The intersection of the optical axis of the laser beam is obtained is characterized in that the measuring point of the object to be measured.

According to a second aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the probe is installed in the direction of gravity with respect to the object to be measured, and is moved by moving in the direction of gravity. It is characterized by measuring the shape of a measured object. The invention according to claim 3 achieves the above object,
The invention according to claim 1, wherein the moving means uses three axes which are not on the same plane as the moving axis, and a plane formed by two of the moving axes is a horizontal plane.

According to a fourth aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the moving means uses three axes which are not on the same plane as the moving axes, and measures displacement among the moving axes. The plane formed by the two axes excluding the direction is parallel to the plane formed by the two axes of the laser light, and the two moving axes and the two axes of the laser light forming the respective planes have a certain angle with each other. It is characterized by.

According to a fifth aspect of the present invention, in order to achieve the above object, in the fourth aspect of the present invention, a plane formed by two moving axes excluding the displacement measuring direction is orthogonal to a moving axis in the displacement measuring direction. It is what it was. According to a sixth aspect of the present invention, in order to achieve the above object, in the fourth aspect of the invention, two axes of a laser beam forming a plane parallel to a plane formed by the two moving axes are respectively orthogonal to each other. It is.

According to a seventh aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the moving means uses three axes that are not on the same plane as the moving axes, and the three axes are orthogonal to each other. , Wherein the three axes of the laser light are orthogonal to each other. The invention (Z-axis stage) according to claim 8, further comprising a displacement measuring probe fixed on a surface plate for measuring a shape of an object to be measured, wherein the probe is attached to the object to be measured. Moving means for moving the moving means in a three-dimensional direction, measuring means for measuring a moving amount of the moving means, and analyzing means for analyzing a moving amount of the moving means based on an output of the measuring means, wherein the moving means An XY biaxial stage provided on a surface plate and moving in a horizontal plane, a gravitational compensation means provided on the surface plate to compensate for the weight of the stage, and a moving amount of each of the stages is measured. In a three-dimensional shape measuring apparatus configured to include a length measuring unit and a Z-axis stage in which the gravity compensation unit is unitized, and to measure a shape of the object to be measured by keeping an output of the probe substantially constant, To Z axis scale, The air slide of the shaft is mounted as a guide shaft, and a voice coil motor is used as a driving force to move the guide shaft, and the Z-axis table equipped with the probe and the laser interferometer for measuring the amount of movement of each axis can be moved in the Z direction. In order to move it with high accuracy, a linear scale detection head is provided on the Z-axis scale, and a linear scale grating is provided on the side surface of the air slide.

The ninth aspect of the invention (gravity compensation means)
In order to achieve the above object, in the invention according to claim 8, the gravity compensating means has a winding drum using a spiral spring above the Z-axis scale, and the spiral spring extended from the winding drum is directly connected to the spiral spring. It is characterized in that it is balanced with the weight applied to the Z-axis table by being lifted in connection with a mounting bracket on the side of the air slide, which is a guide for the Z-axis table.

The invention according to claim 10 (the high-speed and high-accuracy linear scale for measurement) achieves the above object by claim 8.
In the invention described above, a linear scale for measuring a movement amount of a Z-axis table for controlling a voice coil motor for driving the Z-axis is provided independently of the laser interferometer. According to an eleventh aspect of the invention (layout of a length measuring system), in order to achieve the above object, in the invention of the eighth aspect, the X-, Y-, and Z-axis measurement standards fixed on the surface plate are used. Three mirrors, three laser light sources arranged on a Z-axis table for irradiating laser light in three axes of X, Y, and Z, and three laser light sources for reflecting light from the laser light sources to the plane mirror. A reflection mirror and three laser interferometers for detecting interference fringes of laser light incident from the plane mirror via the reflection mirror are used. As a measurement system arrangement, the three laser interferometers are guided by a Z-axis stage. The three laser beams are arranged on the front surface and both side surfaces of the air slide so that the positions where the optical axes of the three laser beams intersect become the measurement points.

According to a twelfth aspect of the present invention (to increase the rigidity of the bobbin of the voice coil motor), in order to achieve the above object, in the invention of the eighth aspect, the bobbin structure of the voice coil motor is hollowed out of a stainless steel block. The bobbin rigidity is increased as an integral structure of the above. According to a thirteenth aspect of the invention (fall prevention means), in order to achieve the above object, in the invention of the eighth aspect, when an abnormality such as poor control of the drive system of the Z-axis stage, the brake using an air cylinder is effective. It is characterized in that it is provided with a fall prevention means.

According to a fourteenth aspect of the present invention (gravity compensation unit), in order to achieve the above object, in the eighth aspect of the invention, the gravity compensating means comprising the spiral spring is unitized and detachably mounted. It is characterized by being interchangeable. The invention according to claim 15 (damper mechanism)
According to a ninth aspect of the present invention, in the ninth aspect of the present invention, a natural vibration caused by the spiral spring is viscously damped by providing a damper in the gravity compensating means including the spiral spring.

[0025]

1 is a right side view of a Z-axis stage in a high-precision three-dimensional shape measuring apparatus according to the present invention. FIG. 2 is a diagram showing a bobbin structure of a voice coil motor according to the present invention. FIG. 3 is a diagram in which the gravity compensation mechanism according to the present invention is unitized, and FIG. 4 is a plan layout diagram of a three-dimensional shape measuring apparatus configured using the Z-axis stage according to the present invention.

An overall base 2 is mounted on a stone surface plate 1 placed on an air spring type vibration isolator (not shown), and X
An XY biaxial stage including a stage 3 and a Y stage 4 is provided, and a Z-axis stage 6 is provided using a Z-axis scale (angle plate) 5 erected thereon as a substrate. This Z
The axis stage 6 attaches a single-axis air slide 7 as a guide axis to the Z-axis scale 5, and uses a voice coil motor 8 as a driving force to move the air slide. As a result, the Z-axis table 9 can be moved in the Z-axis direction, and the object to be measured 11 fixed on the stone platen 1 is measured by the measurement probe 10 attached thereto. On both sides of the Z-axis table 9 and the air slide 7, there are provided laser light sources for irradiating laser beams in the XYZ three-axis directions, and are reflected and returned by plane mirrors (12X, 12Y, 12Z) serving as measurement standards. Laser interferometers (13X, 13Y, 13Z) capable of detecting interference fringes generated by the reflected light, and reflection mirrors (14X, 14X, 12Y, 12Z) used to turn the laser light source back to the plane mirrors (12X, 12Y, 12Z). , 14Y, 14Z)
Is attached. At this time, the lasers are arranged such that the intersection of the optical axes of the lasers is the measurement point of the DUT 11.

A detection head 15 for a linear scale is fixedly attached to the Z-axis scale 5, and a linear scale 17 is attached to a side of the air slide 7 by a holding member 18.
, The amount of movement of the movable Z-axis table 9 can be measured. As shown in FIG. 2, the bobbin member 16 of the voice coil motor 8 is formed by winding a coil around a hollow body made of a stainless steel.

A winding drum 20 is provided on the upper part of the Z-axis scale 5 using a spiral spring 19.
Numeral 0 is rotatably supported at both ends by bearings 21. The spiral spring 19 extends from there and is directly connected to mounting brackets on both sides of the movable side of the air slide 7 which is a guide shaft of the Z-axis table 9 to lift the spiral spring 19, thereby constituting a gravity compensation mechanism. ing.

This gravity compensation mechanism, as shown in FIG.
It is unitized, and can be replaced by simply screwing the box-shaped unit 23 on the base plate 24 protruding from the Z-axis scale 5. The Z-axis stage 6 is extended by an air slide 7 as a fall prevention means between a scissor plate 26 operated by an air cylinder 25 fixed to the back side of the Z-axis scale 5 and a stationary pad 27. The sliding plate 28 slides. Further, a rubber material 29 is attached to the pad 27.

As shown in FIG. 3, a braking force is applied to the rotary motion of the winding drums 20A and 20B by the rotary dampers 30A and 30B fixed above the Z-axis scale 5. I have. Next, a measuring operation in the three-dimensional shape measuring apparatus used in the present embodiment will be described with reference to FIGS. In advance, the DUT 11
The measurement probe 10 moves to the position where the measurement is performed, approaches the position where the measurement probe 10 can be measured, and starts measurement. Specifically, precise measurement is possible by measuring the amount of movement of the Z-axis table 9 on which the measurement probe 10 is mounted while operating in the X-axis direction, which is the main scanning direction. This is done by using the value of a displacement meter (probe reading) so as to keep the distance between the measurement probe 10 and the DUT 11 substantially constant,
Control is performed in the Z-axis direction, and the movement amount δ1 which is the trajectory of the Z-axis table 9 at this time is added to the accurate distance δ2 between the measurement object 11 measured by the displacement meter, and the value of the measurement object The measurement of the shape of No. 11 is performed.

FIG. 5 is a plan layout diagram of the laser length measuring device, as shown in FIG. As shown in FIG. 5, it is assumed that the moving axes are X, Y, and Z axes, respectively, and that the X axis and the Y axis are on the plane of the paper, and the Z axis is for measuring the shape of the object to be measured above the plane of the paper. At this time, the laser length measuring device is arranged at a fixed angle with respect to the X axis and the Y axis on the paper. As a result, the laser beam and the moving direction do not lie on the same straight line, and the mirror does not get in the way, so that the apparatus can be downsized. If the measurement direction is the X axis, the laser length measuring instrument is inclined at a constant angle with respect to the Y axis and the Z axis. If the measurement direction is the Y axis, the laser length measuring instrument is inclined at a constant angle with respect to the X axis and the Z axis. Place.

Further, by providing the gravity compensating means including the spiral spring 19 with a damper utilizing viscous resistance of a fluid or the like in the operation direction, the viscous resistance ratio can be increased, and the gravity of the Z-axis stage can be increased. At the natural frequency caused by the compensation mechanism, it is possible to suppress the vibration,
The gain can be increased in control. FIG. 6 shows the relationship between the frequency and the amplitude using the viscous damping ratio ζ as a parameter in order to show the effect when this damper mechanism is used. As shown in FIG. 6, by using the damper mechanism, the viscous damping ratio ζ can be increased, and the amplitude in the resonance state where the vibration frequency ω becomes equal to the natural frequency ωn of the system can be suppressed. . For example, in the present embodiment, the natural frequency of the system is 1
Viscous damping ratio ζ was around 0.4 when the damper mechanism was not used, but the viscous damping ratio ζ could be improved to 0.7 by using a damper.

[0033]

According to the first aspect of the present invention, the amount of movement of the probe moving along the shape of the object to be measured is measured using the laser length measuring device, and the optical axis of the three-axis laser light that is not on the same plane is measured. Is set as a measurement point, it is possible to prevent Abbe's error from entering the measurement result, and to perform accurate measurement.

According to the second aspect of the present invention, since the probe is oriented in the direction of gravity and measures in the direction of gravity, no inclination due to gravity occurs during the measurement, so that it is not necessary to control the inclination of the probe, and the apparatus is not required to be tilted. Control can be simplified. Claim 3
According to the invention described above, since two of the moving axes are on the horizontal plane, the control can be simplified without being affected by gravity in moving on each axis.

According to the fourth aspect of the present invention, since the axis of movement and the axis of the laser beam do not lie on the same straight line, interference with the reference mirror is not restricted within the stroke, and the entire apparatus can be used. Can be downsized. According to the invention described in claim 5,
Since the plane formed by the two moving axes is orthogonal to the moving axis in the displacement measurement direction, the control of the moving axis can be simplified.

According to the sixth aspect of the present invention, the two axes of the laser beam forming a plane parallel to the plane formed by the two moving axes are orthogonal to each other, so that the measurement of the object to be measured and the control of the moving axis can be easily performed. it can. According to the seventh aspect of the invention, since the three axes of movement and the three axes of the laser beam are orthogonal to each other, it is possible to easily measure the object to be measured and control the axis of movement.

According to the eighth aspect of the present invention, by using a Z-axis stage having a three-axis configuration, precision components can be submicron (length measurement resolution, for example, surface roughness 0.01 μm, surface accuracy 0.1 μm). The Z-axis stage is equipped with a measurement probe and a laser interferometer for measuring the amount of movement of each axis. The Abbe error that occurs can be prevented from being included in the measurement error, and accurate measurement can be performed.

According to the ninth aspect of the present invention, since the gravity compensation mechanism using the spiral spring is provided, since the change of the restoring force with respect to the stage position is small, the control is required to hold the Z-axis stage. Since almost no force is required, the required thrust can be reduced, high-speed operation can be achieved, and the motor can be downsized.
The entire device can be reduced in weight and size. Further, since the stage is directly lifted, there is no need to worry about a decrease in rigidity in the transmission system caused when a wire or the like is used.

According to the tenth aspect of the present invention, high-speed control can be facilitated by controlling the Z-axis stage by position measurement using a linear scale. Since a state in which measurement is impossible due to a laser cutoff or a decrease in laser power, which occurs when used, does not occur, the Z-axis stage can be stably controlled.

According to the eleventh aspect of the present invention, the laser interferometers for measuring the amount of movement of each axis are compactly arranged, so that the interference area of the apparatus accompanying the movement of each axis can be reduced. The entire apparatus can be made compact while securing the arrangement of the paired reference mirrors on the surface plate. For example, a considerably large movable range in the X axis (for example, 300 mm)
It is also possible to measure medium-sized parts.

According to the twelfth aspect of the present invention, the rigidity of the bobbin structural member of the voice coil motor is reduced by increasing the rigidity of the bobbin structural member in response to the problem that the natural frequency of the Z-axis stage is reduced if the rigidity of the bobbin structural member is low. As a result, good control of the Z-axis stage can be realized. According to the thirteenth aspect of the present invention, by using the fall prevention function, it is possible to prevent damage to the Z-axis table and various expensive optical systems attached to the air slide that guides the Z-axis table in an unexpected situation. it can.

According to the fourteenth aspect of the present invention, the gravity compensating mechanism which needs to be replaced according to the life is unitized,
Time and power related to work can be saved. The rigidity can also be increased by screwing each of them. According to the fifteenth aspect of the present invention, the viscous damping ratio of the gravity compensation mechanism can be increased by using the damper utilizing the viscous resistance of the fluid or the like. As for the frequency, it is possible to suppress the occurrence of vibration and to increase the gain in control. As a result, good control can be realized.

[Brief description of the drawings]

FIG. 1 is a right side view of a Z-axis stage in a high-precision three-dimensional shape measuring apparatus according to the present invention.

FIG. 2 is a diagram showing a bobbin structure of the voice coil motor according to the present invention.

FIG. 3 is a diagram in which a gravity compensation mechanism according to the present invention is unitized.

FIG. 4 is a plan layout diagram of a three-dimensional shape measuring apparatus configured using a Z-axis stage according to the present invention.

FIG. 5 is a plan layout diagram of a laser length measuring device according to the present invention.

FIG. 6 is a diagram illustrating a relationship between a frequency and an amplitude using a viscous damping ratio パ ラ メ ー タ as a parameter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface plate 2 Whole base 3 X stage 4 Y stage 5 Z axis scale 6 Z axis stage 7 Air slide 8 Voice coil motor 9 Z axis table 10 Measurement probe 11 Measurement object 12X, 12Y, 12Z Plane mirror 13X, 13Y, 13Z Laser interferometer 14X, 14Y, 14Z Reflecting mirror 15 Detection head 16 Bobbin member 17 Linear scale 18 Holding member 19 Spiral spring 20A, B Winding drum 21 Bearing 23 Unit 24 Base plate 25 Air cylinder 26 Scissor plate 27 Pad 28 Sliding plate 29 Rubber material 30A, B Rotary damper

Claims (15)

[Claims] 1. A moving means for mounting a displacement measuring probe for measuring the shape of an object to be measured fixed on a surface plate, and moving the probe in a three-dimensional direction with respect to the object to be measured. Measuring means for measuring the amount of movement of the object, and laser light irradiating means for irradiating the object to be measured with laser light from within the displacement measurement probe, and the object to be measured is irradiated with laser light from the laser light irradiating means. Based on the laser light reflected from the object, the moving means moves so as to keep the distance between the object and the probe constant, and the measuring means measures the amount of movement of the moving means In the three-dimensional shape measuring apparatus that measures the shape of the object to be measured, the measuring unit measures the amount of movement by the moving unit using a three-axis laser length measuring device that is not on the same plane. Laser length measuring device Three-dimensional shape measuring apparatus, characterized in that the intersection of the optical axis of the laser light and the measurement point of the object to be measured. 2. The three-dimensional shape according to claim 1, wherein the probe is installed in the direction of gravity with respect to the object to be measured, and is moved in the direction of gravity to measure the shape of the object to be measured. measuring device. 3. The three-dimensional apparatus according to claim 1, wherein said moving means uses three axes which are not on the same plane as a moving axis, and a plane formed by two of said moving axes is a horizontal plane. Shape measuring device. 4. The moving means has three axes which are not on the same plane as a moving axis, and a plane formed by two axes of the moving axes excluding a displacement measuring direction is a plane formed by two axes of the laser beam. 3. The three-dimensional shape measuring apparatus according to claim 1, wherein the two axes of movement and the two axes of the laser beam which are parallel to each other have a certain angle with each other. 5. The three-dimensional shape measuring apparatus according to claim 4, wherein a plane formed by the two movement axes excluding the displacement measurement direction is orthogonal to a movement axis in the displacement measurement direction. 6. The three-dimensional shape measuring apparatus according to claim 4, wherein two axes of a laser beam forming a plane parallel to a plane formed by the two moving axes are orthogonal to each other. 7. The apparatus according to claim 1, wherein the moving means uses three axes that are not on the same plane as the moving axis, the three axes are orthogonal to each other, and the three axes of the laser beam are orthogonal to each other. The three-dimensional shape measuring device according to the above. 8. A moving means for mounting a displacement measuring probe for measuring the shape of an object to be measured fixed on a surface plate, and moving the probe in a three-dimensional direction with respect to the object to be measured. Measuring means for measuring the moving amount, and analyzing means for analyzing the moving amount of the moving means based on the output of the measuring means,
XY biaxial stage, wherein the moving means moves on a horizontal plane provided on the surface plate, and gravity compensation for compensating for the weight of a stage erected to be mounted on the XY biaxial stage Means, a length measuring means for measuring an amount of movement of each of the stages, and a Z-axis stage in which the gravity compensating means is unitized, wherein the output of the probe is maintained substantially constant so that the object to be measured is In the three-dimensional shape measuring apparatus for measuring the shape of the probe, a single-axis air slide is attached to the Z-axis scale as a guide shaft, and a voice coil motor is used as a driving force for moving the guide shaft. A Z-axis table on which a laser interferometer for measurement is mounted can be moved in the Z direction, a linear scale detection head is provided on the Z-axis scale, and a linear scale is provided on a side surface of the air slide. Z-axis stage and having a grating portion. 9. The gravity compensating means has a winding drum using a spiral spring above the Z-axis scale, and the spiral spring extended from the winding drum is provided on an air slide as a guide for the Z-axis table. 9. The Z-axis stage according to claim 8, wherein the Z-axis stage is balanced with the weight applied to the Z-axis table by being lifted in connection with a mounting bracket on a side surface. 10. The Z-axis according to claim 8, further comprising a linear scale for measuring a movement amount of a Z-axis table for controlling a voice coil motor for driving said Z-axis, independently of said laser interferometer. Axis stage. 11. A three-plane mirror as a measurement reference in X, Y, and Z directions fixed on the surface plate, and an X, Y, and Z directions arranged on a Z-axis table. Three laser light sources that irradiate the laser light to the light source, three reflection mirrors that reflect light from the laser light source to a plane mirror, and interference fringes of the laser light incident from the plane mirror via the reflection mirror are detected. Three laser interferometers are provided, and the three laser interferometers are positioned on the front surface and both side surfaces of the air slide, which is a guide of the Z-axis stage, so that the positions where the optical axes of the three laser beams intersect become measurement points. 9. The Z-axis stage according to claim 8, wherein the Z-axis stage is arranged on a stage. 12. The Z-axis stage according to claim 8, wherein the bobbin structure of said voice coil motor is formed as an integral structure formed by hollowing out a stainless steel block to increase bobbin rigidity. 13. The Z-axis stage according to claim 8, further comprising a fall prevention means for applying a brake using an air cylinder when an abnormality such as a control failure of the drive system of the Z-axis stage occurs. 14. A gravity compensation means comprising a spiral spring,
9. The Z-axis stage according to claim 8, wherein the Z-axis stage is unitized and detachably replaceable. 15. The Z-axis stage according to claim 9, wherein said gravity compensating means comprising a spiral spring includes a damper utilizing a viscous resistance of a fluid or the like in an operation direction.