JP6786255B2 - Shape measuring method, shape measuring device, and data processing method - Google Patents

Description

The present invention relates to a shape measuring device , a shape measuring device, and a data processing method of a shape measuring device that scans an object with a contact probe and measures the shape data of the object.

Conventionally, when measuring the surface shape of an optical element such as a spherical or aspherical lens, a contact (or non-contact type) probe is moved following the lens surface, and the surface shape is measured from the movement locus. It has been known.

In general, when the surface shape of an optical element such as a lens having many rotationally symmetric shapes is measured by probe scanning, the shape measuring device is used to scan the probe in addition to the axis (for example, Z axis) that moves the probe along the shape. It may be sufficient to arrange only one other axis (for example, the X axis). That is, at least two relative movement axes are arranged in this type of shape measuring device. These two axes are, for example, an axis for relatively moving the object and the probe in the first direction (for example, the X axis) and moving the probe in the second direction according to the surface shape of the object (for example, vertical movement). It is a 2 (X, Z) axis of an axis (for example, Z axis) that supports it as possible.

As a form of the device, for example, there is a configuration in which an X stage for moving a probe for scanning a work in the X-axis direction is horizontally arranged on an upper part of a portal-shaped support structure. In this case, the work is positioned between the columns on both sides that support the X stage (inside the "gate" shape). Then, while scanning the work, the probe moves in the Z-axis (up and down) direction orthogonal to the X-axis according to the surface shape of the work, and the position (Z coordinate) of the probe in the Z-axis direction is set as the scanning position (Z coordinate). Record in association with (X coordinate). The shape measurement data of the work can be acquired as a sequence of (Z, X) coordinates obtained in this way.

In such a measurement method, the shape measurement accuracy is affected by an error from the degree of orthogonality (orthogonality) of the XZ2 axis. Further, in the contact type probe, the tip portion in contact with the work is formed in a predetermined shape defined by the specifications such as a spherical surface, but the shape error of the tip portion (tip) of the probe with respect to the predetermined shape has an influence. To do.

Conventionally, regarding the correction of the shape error of the tip of the contact type probe, for example, a method of scanning a reference gauge in the form of a knife edge with the probe to measure the shape error of the tip and correcting the workpiece measurement trajectory. Has been proposed (for example, Patent Document 1 below). In this Patent Document 1, the error regarding the orthogonality of the XZ axis is hardly considered.

Japanese Patent No. 3025413

Therefore, in order to calibrate the shape measuring device, it is conceivable to measure the XZ orthogonality error separately from the measurement of the shape error of the tip of the probe. For example, some prototype is probe-scanned to measure the XZ orthogonality error and generate orthogonality correction data. However, in the uncalibrated initial state, probe shape error and XZ orthogonality error are mixed, and no matter which measurement is performed first, the other should be measured without being affected by one of them. Is difficult.

In view of the above problems, the object of the present invention is to obtain correction data capable of accurately correcting the shape error at the tip of the probe of the shape measuring device without being affected by the orthogonality error of the movable axis of the shape measuring device. To do. That is, the shape error of the tip of the probe and the orthogonality error of the movable axis are measured without being affected by one of them, and each of the above errors is corrected with good correction accuracy to perform highly accurate shape measurement. To be able to do it.

In order to solve the above problems, in the present invention, the object of shape measurement and the contact-type probe are supported by a first stage for relative movement in a first direction and the first stage, and the first stage is supported. A second stage that movably supports the probe in a second direction orthogonal to the stage, and a first scale that detects relative position information of the object and the probe in the first direction. A second scale for detecting the position information of the probe with respect to the second direction, and the object and the object by the first stage in a state where the probe is in contact with the surface of the object. The probe is relatively moved, and at that time, the position information regarding the first direction of the object detected via the first scale and the surface shape of the object detected via the second scale are imitated. In the shape measuring method of the shape measuring device for measuring the shape data of the object based on the position information regarding the second direction of the probe moving along the second direction, the control device is the target. As the object, a first prototype for probe calibration having a known curved shape is used, and the object and the probe are relatively moved by the first stage, and the position information of the probe is obtained. a first measurement step of acquiring shape data of the first standard, the control device, from the first measurement the first obtained in step of the shape data of standard, the first and second As the error component corresponding to the theoretical value of the orthogonality error of the stage, the shape data obtained by removing the tertiary component of the shape data of the first prototype obtained in the first measurement step and the first source A configuration including a probe shape correction data acquisition step for acquiring the shape correction data of the probe based on the known shape data of the device was adopted.

According to the above configuration, the shape data obtained by removing the error component corresponding to the theoretical value of the orthogonality error of the first and second stages from the acquired shape data of the first prototype, and the first Based on the known shape data of the prototype, the shape correction data of the probe is acquired. Therefore, it is possible to acquire probe shape correction data capable of accurately correcting the shape error of the tip of the probe without being affected by the orthogonality error of the first and second stages of the shape measuring device. After that, the acquired probe shape correction data can be used, for example, when acquiring correction data for the orthogonality error of the first and second stages. As a result, the shape error of the tip of the probe and the orthogonality error of the movable axis are measured without being affected by one of them, and each of the above errors is corrected with good correction accuracy, thus providing a highly accurate shape. Measurements can be made.

It is a perspective view which showed the structure at the time of shape measurement of the object of the shape measuring apparatus which carried out this invention. It is a block diagram which showed the structure of the measurement control part of the shape measuring apparatus of FIG. It is a flowchart which showed the whole calibration processing procedure of the shape measuring apparatus of FIG. It is a flowchart which showed the probe shape correction procedure in the calibration process of the shape measuring apparatus of FIG. It is a flowchart which showed the XZ orthogonal degree correction procedure in the calibration process of the shape measuring apparatus of FIG. It is a flowchart which showed the measurement control procedure at the time of the shape measurement of the object of the shape measuring apparatus of FIG. It is a diagram of the probe shape correction data including the XZ axis orthogonality error measured by the probe shape correction in the calibration process of the shape measuring apparatus of FIG. FIG. 5 is a diagram showing an XZ-axis orthogonality error included as a cubic or asymmetric component in the waveform of the probe shape correction data of FIG. 7. It is a diagram which showed the probe shape correction data which did not include the XZ axis orthogonality error which removed the 3rd order or asymmetric component of FIG. 8 from the probe shape correction data of FIG. It is a front view which showed the structure at the time of performing scale correction of X-axis and Z-axis in the shape measuring apparatus of FIG. It is explanatory drawing which showed the data flow at the time of performing scale correction of X-axis in the shape measuring apparatus of FIG. It is explanatory drawing which showed the data flow at the time of performing the scale correction of the Z axis in the shape measuring apparatus of FIG. It is a front view which showed the structure at the time of performing the run correction of the X-axis stage in the shape measuring apparatus of FIG. It is explanatory drawing which showed the data flow at the time of performing the run correction of the X-axis stage in the shape measuring apparatus of FIG. It is a front view which showed the structure at the time of performing the run correction of a Z-axis stage in the shape measuring apparatus of FIG. It is explanatory drawing which showed the data flow at the time of performing the run correction of a Z-axis stage in the shape measuring apparatus of FIG. It is a front view which showed the structure at the time of performing probe shape correction or XZ axis orthogonality correction in the shape measuring apparatus of FIG. It is explanatory drawing which showed the data flow at the time of performing probe shape correction in the shape measuring apparatus of FIG. It is explanatory drawing which showed the data flow at the time of performing the XZ axis orthogonality correction in the shape measuring apparatus of FIG. It is explanatory drawing which showed the data flow at the time of shape measurement of the object of the shape measuring apparatus of FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the examples shown in the accompanying drawings. It should be noted that the examples shown below are merely examples, and for example, those skilled in the art can appropriately change the detailed configuration without departing from the spirit of the present invention. Further, the numerical values taken up in the present embodiment are reference numerical values and do not limit the present invention.

<Example>
FIG. 1 shows the configuration of a shape measuring device capable of carrying out the present invention in the form of a perspective view. In FIG. 1, the main body surface plate 101 of the shape measuring device 100 is arranged on a vibration isolation table 102 supported by a gantry 103 so as not to transmit external vibration to the device main body. The direction of each coordinate axis of the three-dimensional (XYZ) coordinate system used for controlling the device may be arbitrarily taken, but in this embodiment, each coordinate axis of X, Y, and Z is taken as shown in the upper left of FIG. There is.

On the main body surface plate 101, the X-axis stage guide 105 is arranged by the frame 104 so that, for example, the entire body has a gate shape.

The object 109 (for example, a workpiece), which is the object to be measured (measurement object), is arranged under the portal shape of the frame 104 and the X-axis stage guide 105, and is scanned by the contact probe 108.

The probe 108 is attached to the Z-axis stage slider 107 of the Z-axis stage guide 106 that is moved in the X-axis direction (first direction) by the X-axis stage guide 105, and moves up and down according to the shape of the object 109. The Z-axis stage guide 106 is attached to the X-axis stage guide 105 via the X-axis stage slider 121, and is driven in the X-axis direction (first direction) by the X-axis stage guide 105.

The probe 108 is attached to the Z-axis stage slider 107 and can move in the Z-axis direction (second direction) along the Z-axis stage guide 106.

For convenience, in this embodiment, of the two axes corresponding to the moving directions of the X and Z axes, the X axis is referred to as the first stage axis and the Z axis is referred to as the second stage axis.

A drive motor (not shown) such as a shaft motor is mounted on the X-axis stage guide 105, and the drive source moves the X-axis stage slider 121 in the X-axis direction. A drive motor (not shown), such as a linear motor, is mounted on the Z-axis stage guide 106, and the drive source drives the Z-axis stage slider 107 in the Z-axis (vertical) direction.

The X-axis stage guide 105 and the X-axis stage slider 121 constitute a first stage for relatively moving the object for shape measurement and the contact probe 108 in the first direction. Further, the Z-axis stage guide 106 and the Z-axis stage slider 107 are supported by the first stage, and constitute a second stage that movably supports the probe 108 in a second direction orthogonal to the first stage. ..

In order to measure the current position information of the X-axis stage slider 121 on the X-axis stage guide 105 in the X-axis direction, in this embodiment, for example, the X-axis scale adopts a double scale configuration of two sets. That is, the X-axis scale 114 is supported on the main body surface plate 101 below the X-axis stage guide 105 via the X-axis scale frame 113.

The second X-axis scale 116 is supported on the main body surface plate 101 below the X-axis stage guide 105 via the X-axis scale frame 115. In this example, the position of the X-axis scale 116 is on the back (Y +) side of the X-axis scale 114.

Further, the scale head for measuring the X coordinate of the X-axis stage slider 121 is arranged below the X-axis stage slider 121 by the X-axis scales 114 and 116. The scale head 117, which measures the X coordinate using the X-axis scale 114, is supported on the lower surface of the X-axis stage slider 121 via the X-axis scale head frame 118 so as to face the X-axis scale 114. On the other hand, the scale head (details not shown in FIG. 1) that measures the X coordinate using the X-axis scale 116 is an X-axis stage so as to face the X-axis scale 116 via the X-axis scale head frame 120. It is supported on the lower surface of the slider 121.

When a plurality of scales are arranged such as the X-axis scales 114 and 116, the X coordinate of the X-axis stage slider 121 is an operation (for example, a measured value) in which the measured values of the plurality of X-axis scales (114 and 116) are combined. It can be calculated by (such as an operation that takes the average of).

Further, the Z-axis stage guide 106 incorporates a Z-axis scale 1071 (details not shown) for measuring the current position information of the Z-axis stage slider 107 in the Z-axis direction.

The X-axis scales 114 and 116 constitute a first scale for detecting relative position information between the probe 108 and the object 109 in the X-axis direction (first direction). Further, the Z-axis scale 1071 constitutes a second scale for detecting the position information of the probe in the Z-axis direction (second direction).

The probe 108 includes a contact that is supported via a leaf spring. For example, the amount of deflection of the leaf spring adjusts the contact pressure of the contactor with respect to the object 109 when it comes into contact with the surface of the object 109 to be measured (measurement target). When the Z-axis stage slider 107 is located at the center of the stroke, each part is arranged so that the tip of the contact of the probe 108 and the heights of the two X-axis scales 114 and 116 in the Z direction are substantially the same. ..

The probe 108 may be provided with a displacement sensor 701 that measures the position of the contactor with respect to the housing of the probe portion. The displacement sensor of the probe 108 can be composed of, for example, a laser length measuring device, a reflection type optical sensor, or the like, similarly to the displacement sensor 701 described above. For example, the leaf spring of the probe 108 is controlled by bringing the contact of the probe 108 into contact with the object 109 and controlling the Z-axis position of the Z-axis stage slider 107 so that the displacement amount of the displacement sensor shows a constant value. The amount of deflection can be adjusted to be constant. By making such adjustments, the contact pressure of the contactor with respect to the object 109 can be controlled to be constant.

Further, a tilt stage 110 is provided to control the tilted posture of the object 109. The tilt stage 110 is configured by using, for example, two axes of rotational drive units that can incline the object 109 in a direction substantially orthogonal to each other (for example, around an axis parallel to the X and Y axes). Below the tilt stage 110, an XY stage 111 that moves the object 109 and the tilt stage 110 in parallel (translation) in a substantially orthogonal direction (for example, in the XY plane) is arranged. Further below, the θ rotation stage 112 that rotationally displaces the XY stage 111 to the tilt stage 110 to 10 to the object 109 around the rotation axis parallel to the Z axis is arranged.

The electrical rack 122 is a driver (drive circuit) for driving the drive system of the main body, for example, the X-axis stage slider 121 mounted on the X-axis stage guide 105 and the Z-axis stage slider 107 mounted on the Z-axis stage guide 106. ) Is provided. Further, the electrical rack 122 includes a driver for driving the two-axis tilt stage 110, the XY stage 111, and the θ rotation stage 112.

Further, the electrical rack 122 includes an interface (circuit) for inputting data corresponding to the first and second X-axis scale positions output by the first and second X-axis scale heads 117 and 119, respectively. .. The electrical rack 122 also includes an interface for inputting data from a scale (not shown) incorporated in the Z-axis stage guide 106. Further, the electrical rack 122 is also provided with an interface for inputting contactor position data output by a displacement sensor (not shown) arranged on the contactor.

The measurement control device 123 controls the correction process described later and the entire shape measurement process. For example, the measurement control device 123 commands each driver of the electrical rack 122 to provide information regarding the moving positions of the X-axis stage slider 121 and the Z-axis stage slider 107 mounted on the X-axis stage guide 105. Further, the moving positions of the tilt stage 110, the XY stage 111, and the θ rotation stage 112 are instructed to each driver mounted on the electrical rack 122. Further, the position detection data of each part input from each interface of the electrical rack 122 can be input.

In the correction and measurement control procedure described later, the measurement control device 123 controls the entire correction process and shape measurement process described later through the input / output process described above. A control program for controlling the entire correction process and shape measurement process described later via the input / output process for each of the above units can be stored in a storage device such as a ROM. Such a storage device for storing a program corresponds to a computer-readable recording medium that stores a control program for executing the correction or shape measurement control procedure of the present invention. Although the measurement control device 123 is shown independently in FIG. 1, it may be configured to be incorporated in the electrical rack 122.

Further, the measurement data processing device 124 (data processing computer) manages measurement condition parameters and the like, and constitutes, for example, a user interface means for a manager or a worker (user) involved in the measurement processing. The measurement conditions managed by the measurement data processing device 124 include the measurement range, the number of measurements, the measurement speed, the measurement type, the design value shape of the object, and the like related to each of the scales and displacement sensors. For example, the measurement data processing device 124 uses these parameters specified by the user as measurement parameters and sends them to the measurement control device 123 together with the measurement procedure data. Thereby, for example, the shape measurement of the object 109 including the prototype for calibration can be performed under the measurement control conditions specified by the user. Further, the measurement data processing device 124 is equipped with a data acquisition program that acquires data of each scale and displacement sensor data from the measurement control device 123.

Further, the measurement data processing device 124 includes a shape data calculation program that calculates the surface shape of the object 109 from the captured scale data and displacement sensor data. Further, the measurement data processing device 124 includes an error calculation program that calculates the calculated shape data of the object 109 and the error from the design value of the object 109 from the design value shape of the object 109.

Further, the measurement data processing device 124 is a shape position calculation program that calculates the three-dimensional position where the object 109 is placed with respect to the origin and coordinates of the device or an arbitrary origin and coordinates from the calculated shape data of the object 109. To be equipped.

Further, the measurement data processing device 124 of this embodiment includes a correction data calculation program for the tip shape of the probe 108, that is, a probe shape correction program. When executing this probe shape correction program, a prototype with a known shape (for example, a quadric surface shape) is used as the object 109, as will be described later.

Further, the measurement data processing device 124 includes a program for calculating the orthogonality error between the X-axis stage guide 105 and the Z-axis stage guide 106 from the measured shape data, that is, an XZ orthogonality correction program. When executing this XZ orthogonality correction program, a prototype with a known shape is used as the object 109.

In FIG. 1, the measurement data processing device 124 and the measurement control device 123 are shown as if they were separate bodies. Further, it has been described above that the measurement control device 123 and the measurement data processing device 124 are appropriately assigned control functions. However, the above configuration is only for convenience to facilitate understanding. For example, in terms of mounting, the measurement data processing device 124 and the measurement control device 123 can be configured by an architecture configured around the same (common) CPU. Further, regardless of whether the measurement data processing device 124 and the measurement control device 123 are separate, the same (common), or integrated, they can be mounted at an appropriate position such as in the electrical rack 122. ..

FIG. 2 shows a configuration example of a control system constituting the measurement control device 123 (or the measurement data processing device 124). Here, the configuration of the measurement control device 123 is shown as a configuration representative of these control or processing devices. However, for example, the configuration of FIG. 2 can be diverted to the measurement data processing device 124. In that case, for example, the electrical rack 122 connected to the interface 1607 may be read as the measurement control device 123, and the block of the measurement data processing device 124 in the figure connected to the interface 1608 may be omitted. Further, in the case of a control system configuration in which the measurement control device 123 and the measurement data processing device 124 are integrated, a configuration in which the block of the measurement data processing device 124 in the figure connected to the interface 1608 is omitted may be considered. .. For example, as shown in FIG. 2, a configuration in which each peripheral device unit is connected to a system bus (not shown) centered on the CPU 1601 can be configured by using hardware such as a PC (personal computer). ..

The CPU 1601 is configured by using, for example, various general-purpose microprocessors. The storage space of the CPU 1601 used as various correction data storage units described later is composed of, for example, an address space such as ROM 1602 and RAM 1603, or a virtual storage area allocated to an external storage device such as HDD 1604.

In the configuration of FIG. 2, a display 1605 configured by using an LCD panel or the like and a keyboard 1606 (and a pointing device such as a mouse or a trackpad) are shown as user interface means. The configuration of such a user interface is an example, and for example, a configuration such as a touch panel in which a display surface and an input operation surface are integrated may be used. Further, voice input / output means may be used as necessary for the user interface.

The procedures of the system error (system error) calibration (correction) process and the shape measurement process of the object (workpieces of various industrial products) in the shape measuring device 100 of FIG. 1 are shown in FIGS. 3 to 6. These control procedures are executed, for example, by the CPU 1601 of FIG. 2 as a control device. In that case, it does not matter whether the control (processing) system of FIG. 2 is implemented as the measurement control device 123 or the measurement data processing device 124. The control program for causing the CPU 1601 to execute the control (processing) procedure shown in each of these figures can be stored in the ROM 1602 or the HDD 1604.

FIG. 3 shows a control procedure for system error (system error) calibration (correction) processing in the shape measuring device 100. The system error (system error) is an error mainly possessed by the hardware of the shape measuring device 100, and the shape of the object cannot be accurately measured unless the shape measuring device 100 is corrected.

This system error (system error) includes, for example, in the case of the shape measuring device 100 of this embodiment, an error related to the linearity of the measured values of the X-axis and Z-axis scales. The error correction data (scale linearity correction data) related to the linearity of the X and Z-axis scales is the X-axis / Z-axis scale correction processing (scale linearity correction data acquisition step) in steps S1301 and S1302 of FIG. Get it with. Further, FIG. 10 shows an example of the hardware configuration of the shape measuring device 100 when the X-axis / Z-axis scale correction processing of steps S1301 and S1302 of FIG. 3 is performed. Further, FIG. 11 shows a data flow of the control system (FIG. 2) when the X-axis scale correction process of step S1301 of FIG. 3 is performed. FIG. 12 shows the data flow of the control system (FIG. 2) when the Z-axis scale correction process of step S1302 of FIG. 3 is performed.

In addition, the system error (system error) includes the running error of the X-axis stage and the Z-axis stage, that is, when these stages operate in each axial direction, the direction orthogonal to (or intersects with) these movable axes. Blurring is included. The correction data of the running error of the X-axis and Z-axis stages is acquired by the stage running correction processing of the X-axis / Z-axis in steps S1303 and S1304 of FIG. FIG. 13 shows an example of the hardware configuration of the shape measuring device 100 when the X-axis stage run correction process of step S1303 of FIG. 3 is performed, and FIG. 14 shows a data flow of the control system (FIG. 2) at that time. Is shown. Further, FIG. 15 shows an example of the hardware configuration of the shape measuring device 100 when the Z-axis stage run correction process of step S1304 is performed, and FIG. 16 shows the data flow of the control system (FIG. 2) at that time. Shown.

The system error (system error) includes the above-mentioned probe shape error and the XZ orthogonality error of each (XZ) axis of the X-axis stage and the Z-axis scale. As described above, these probe shape errors and XZ orthogonality errors occur in a mixed state in the uncalibrated stage. Therefore, in order to obtain correction data for these two errors, the components corresponding to the two errors must be separately measured by some method. The correction data of the probe shape error and the XZ orthogonality error are acquired in steps S1305 and S1306 of FIG. FIG. 17 shows an example of the hardware configuration of the shape measuring device 100 when the probe shape correction process and the XZ orthogonality correction process are performed in steps S1305 and S1306 of FIG. Further, FIG. 18 shows the data flow of the control system (FIG. 2) in the probe shape correction process of step S1305 in FIG. 3, and FIG. 19 shows the control system (FIG. 2) in the XZ orthogonality correction process of step S1306 of FIG. ) Data flow is shown.

The details of the probe shape error correction process (step S1305 in FIG. 3) and the XZ orthogonality error correction process (S1306), which are related to each other, are shown in the flowcharts of FIGS. 4 and 5, respectively.

The shape measurement process of an object (workpiece of various industrial products) can be executed by, for example, the procedure shown in FIG. The hardware configuration of the shape measuring device 100 at this time is as shown in FIG. 1, for example. The data flow of the control system (FIG. 2) in the shape measurement process of the object (workpiece of various industrial products) is as shown in FIG. Prior to the "production" measurement of FIGS. 6 (1 and 20), the system error (system error) calibration (correction data acquisition) process shown in FIGS. 3 to 5 is performed.

FIG. 10 shows the state of the shape measuring device 100 when acquiring the scale correction data for correcting the scale error of the X-axis scales 114 to 116 and the Z-axis scale 1071 for measuring the position in the Z-axis direction. The illustration of FIG. 10 corresponds to the illustration from the front direction of FIG.

In the configuration of FIG. 10, the probe 108 is replaced with the target 201 of the laser length measuring instruments 203 and 204. The target 201 is configured in a cubic (or rectangular parallelepiped) shape having a reflective (mirror) surface capable of reflecting laser light on the bottom surface and the side surface. The target 201 for such laser measurement is sometimes called a mirror cube or the like.

The target 201 is mounted on the Z-axis stage slider 107 instead of the probe 108, and is moved and controlled in the X- and Z-axis directions by the X-axis stage slider 121 and the Z-axis stage slider 107. At that time, the actual coordinates of the target 201 in the X and Z axis directions measured by the laser length measuring instruments 203 and 204, and the X and Z axis directions measured via the X axis scales (114 and 116) and the Z axis scale 1071. The correction data corresponding to the scale error is acquired from the coordinates of.

The laser length measuring devices 203 and 204 are provided with a laser light source and a receiver, respectively, so that the distances of the target 201 in the X and Z axis directions can be measured via the interference state of the emitted light and the reflected light from the target 201. It is composed.

When measuring in the X-axis direction using the laser length measuring device 203, the CPU 1601 uses the Z-axis stage slider 107 to reflect the height of the target 201 and the reflecting surface on the side surface of the target 201 reflecting the laser light of the laser length measuring device 203. Control as much as possible. While maintaining this Z-axis position, the target 201 is moved in the X-axis direction by the X-axis stage slider 121 to acquire the measured value of the distance in the X-axis direction from the laser length measuring instrument 203, and the X-axis scale (114, The output value of 116) is acquired.

On the other hand, when the laser length measuring device 204 is used for measurement in the Z-axis direction, a reflecting surface inclined at, for example, 45 ° on the upper surface of the main body surface plate 101 in order to reflect the laser light of the laser length measuring device 204. The bender mirror 202 having the above is arranged. At this time, the bender mirror 202 is arranged so as to reflect the laser beam passing through the perpendicular line passing through the mounting center of the target 201 (or the probe 108), for example. When measuring in the Z-axis direction, the CPU 1601 naturally operates the Z-axis stage slider 107 while maintaining the X-axis position by the X-axis stage slider 121. Then, the measured value of the distance in the Z-axis direction is acquired from the laser length measuring device 204, and the output value of the Z-axis scale 1071 is acquired.

When acquiring any of the X-axis and Z-axis scale correction data, the outputs of the laser length measuring instruments 203 and 204 and the outputs of the X-axis scales (114 and 116) and the Z-axis scale 1071 are taken in synchronously.

11 and 12 show the data flow when acquiring the X-axis and Z-axis scale correction data of the X-axis scales (114 and 116) and the Z-axis scale 1071, respectively. In FIGS. 11 and 12, 301 and 401 indicate the input processing of the length measurement data from the laser length measuring instruments 203 and 204, respectively. Further, 302 and 402 indicate input processing of scale measurement data from the X-axis scale (114, 116) and the Z-axis scale (1071), respectively. These length measurement and measurement data are synchronously read from the electrical rack 122 via the interface 1607 of FIGS. 1 and 2 via clock synchronization control or the like.

In FIGS. 11 and 12, the length measurement data (301, 401) in the X-axis and Z-axis directions actually measured by the laser length measuring devices 203 and 204 and the measurement data (302, 402) on the X-axis and Z-axis scales are synchronized. The X-axis and Z-axis scale correction value calculation (303, 403) is performed.

In the X-axis and Z-axis scale correction value calculation (303, 403), for example, the measured values read from the X-axis and Z-axis scales in the actual measurement of the object are simultaneously read by the laser length measuring instruments 203 and 204. Generate correction data that can be converted to measured values. Such correction data of the X-axis and Z-axis scales are, for example, the measured length measurement data (301, 401) in the X-axis and Z-axis directions and the measurement data (302, 402) of the X-axis and Z-axis scales. It can be generated by taking the difference.

Then, the CPU 1601 stores the X-axis and Z-axis scale measurement data generated by the X-axis and Z-axis scale correction value calculations (303 and 403) in the X-axis and Z-axis scale correction data storage units (304 and 404). .. The X-axis and Z-axis scale correction data storage units (304, 404) are assigned to predetermined storage positions of the above-mentioned RAM 1603, HDD 1604 or a virtual storage area composed of these.

Note that FIG. 11 is shown as data processing of one X-axis scale without distinguishing between the two X-axis scales (114, 116). When actually arranging two X-axis scales (114, 116), in the X-axis and Z-axis scale correction value calculation 303, the measurement data of each X-axis scale and the laser length measuring instrument 203 are synchronously read. The difference from the length measurement data may be generated. As a result, X-axis scale correction data that can be converted so that the measured values of each X-axis scale (114, 116) match the length-measured data actually measured by the laser length measuring device 203 is generated, and the X-axis scale correction data is generated. It can be stored in the storage unit (304).

FIG. 13 shows an example of the setting state of the shape measuring device 100 when performing running correction (acquisition of correction data for X-axis running error) of the X-axis stage. The configuration in the figure is for measuring the movement error correction value of the X-axis stage slider 121 of the X-axis stage guide 105.

In the configuration of FIG. 13, the probe 108 is mounted on the Z-axis stage slider 107, and the shape of the planar prototype 501 is measured by the probe 108. For example, the upper surface of the plane prototype 501 is formed of a plane having a known shape. It is more desirable if the plane accuracy of the upper surface of the plane prototype 501 is good, but if the shape is known, it is not impossible to acquire correction data for the X-axis running error even if the shape is close to a plane. The shape of the planar prototype 501 is obtained in advance by an inversion method or the like, and the shape data is stored in ROM 1602, HDD 1604, or the like.

FIG. 14 shows a data flow when performing X-axis stage run correction. This "X-axis stage running" corresponds to vertical movement in the Z-axis direction when the X-axis stage slider 121 is scanned in the X-axis direction on the X-axis stage guide 105. In this X-axis stage run correction, the X-axis stage slider 121 is moved in the X-axis direction on the X-axis stage guide 105, and the Z-axis coordinates of the probe 108 that moves up and down according to the upper surface shape of the plane prototype 501 are captured.

In FIG. 14, 601 shows prototype measurement data (Z-axis coordinates) measured via a Z-axis scale (not shown). In the X-axis stage run correction, a sequence for measuring the shape of the plane prototype 501 is sent from the measurement data processing device 124 to the driver of each stage of the main surface plate 101 via the electrical rack 122, and the measurement is started. The measurement result is input (601) from the Z-axis scale 1071 via the electrical rack 122.

The CPU 1601 performs an X-axis stage run correction value calculation (602) for calculating the run correction data of the X-axis stage based on the prototype measurement data (601) and the shape data of the plane prototype 501 stored in the ROM 1602 or the like in advance. Do. At this time, the Z-axis coordinates of the probe 108 are processed in association with the X-axis coordinates of the X-axis stage slider 121. At that time, these X-axis and Z-axis coordinates are read from the X-axis scale (114, 116) and the Z-axis scale (1071), respectively. The output values read from these X-axis and Z-axis scales were corrected by the X-axis and Z-axis scale correction data stored in the X-axis and Z-axis scale correction data storage units (304, 404: FIGS. 11 and 12). Used above.

The run correction data of the X-axis stage acquired by the X-axis stage run correction value calculation (602) is stored in the X-axis stage run correction data storage unit (603). This X-axis stage run correction data is, for example, the deviation in the Z-axis direction between the Z-axis coordinates read from the Z scale for each X-axis scanning position (X-axis coordinates) and the stored shape data of the plane prototype 501. It can be expressed in a format that stores it. The X-axis stage run correction data storage unit (603) is assigned to a predetermined storage position of the above-mentioned RAM 1603, HDD 1604 or a virtual storage area composed of these.

FIG. 15 shows a setting state of the main body surface plate 101 that performs Z-axis stage running correction. This "Z-axis stage running" corresponds to a shake in the X-axis (horizontal) direction when the Z-axis stage guide 106 scans the Z-axis stage slider 107 in the Z-axis direction. In this Z-axis stage run correction, the Z-axis stage slider 107 is moved in the Z-axis direction on the Z-axis stage guide 106. At that time, the displacement sensor 701 mounted on the Z-axis stage slider 107 instead of the probe 108 measures the shake of the Z-axis stage slider 107 in the X-axis (horizontal) direction.

The displacement sensor 701 is, for example, a laser length measuring device or a reflection type optical sensor, and is composed of two sensor units facing each other in the X-axis direction as shown in the figure. The prototype 702 is arranged on the main body surface plate 101. The prototype 702 is arranged on the main body surface plate 101 so as to be scanned at substantially the center position of the two sensor units of the displacement sensor 701 at the X coordinate for performing the Z-axis stage running correction.

At least one surface of the prism for correcting the Z-axis stage run of the prototype 702 is formed as a run reference surface. Desirably, one facing surface is also formed as a reference surface. More preferably, the remaining two opposing surfaces are also formed as reference surfaces. The X-axis coordinates of the X-axis stage slider 121 are controlled so as to sandwich the (square pillar) prototype 702 as described above, and at this position, the Z-axis stage slider 107 is scanned in the Z-axis direction to scan the displacement sensor. The distance (distance in the X-axis direction) from the prototype 702 is measured by 701.

FIG. 16 shows a data flow when performing Z-axis stage run correction. In the figure, 801 indicates measurement data (Z-axis coordinates) measured via the Z-axis scale 1071 in response to the movement of the Z-axis stage slider 107. Further, 802 indicates the displacement sensor data (displacement in the X-axis direction) input from the displacement sensor 701.

The CPU 1601 Z is based on the displacement sensor data (displacement in the X-axis direction) input from the displacement sensor 701 in synchronization with the Z-axis scanning coordinates (801) of the Z-axis stage slider 107 and the known shape data of the prototype 702. The axis stage run correction calculation (803) is performed. At this time, the displacement sensor data (displacement in the X-axis direction) input from the displacement sensor 701 is processed in association with the Z-axis coordinates of the Z-axis stage slider 107. At that time, the Z-axis coordinates are read from the Z-axis scale 1071, and the output value of the Z-axis scale 1071 is corrected by the Z-axis scale correction data stored in the Z-axis scale correction data storage unit (404: FIG. 12). It is used after

Further, the control value of the X-axis coordinates of the X-axis stage slider 121 when performing the Z-axis stage run correction is, for example, constant and does not change. On the other hand, in order to accurately measure the measured value of the distance (distance in the X-axis direction) between the displacement sensor 701 and the prototype 702 from the displacement sensor data (displacement in the X-axis direction) output by the displacement sensor 701, the X-axis stage slider 121 X-axis coordinates are measured on an X-axis scale (114, 116). Further, the output values of the X-axis scales (114, 116) are used after being corrected by the X-axis scale correction data stored in the X-axis scale correction data storage unit (304: FIG. 11).

The run correction data of the Z-axis stage acquired by the Z-axis stage run correction value calculation (803) is stored in the Z-axis stage run correction data storage unit (804). This Z-axis stage run correction data is, for example, the deviation (blur) of the X-axis coordinates acquired from the displacement sensor data (displacement in the X-axis direction) output by the displacement sensor 701 for each Z-axis scanning position (Z-axis coordinates). It can be expressed in a format that stores it. As a matter of course, the deviation of the X-axis coordinates can be calculated based on the shape data of the plane prototype 501 stored in the ROM 1602 or the like. The Z-axis stage run correction data storage unit (804) is assigned to a predetermined storage position of the above-mentioned RAM 1603, HDD 1604 or a virtual storage area composed of these.

FIG. 17 shows an example of the setting state of the shape measuring device 100 when generating the probe shape correction data or the orthogonality correction data of the X-axis and the Z-axis. The measurement of these two correction data (probe shape correction and XZ orthogonality correction) is the core of the calibration process of the shape measuring device 100 in this embodiment, and is performed through the shape measurement of the prototype 901 such as a spherical surface. To do.

However, in the probe shape correction data measurement and the XZ orthogonality correction data measurement, a prototype 901 having a different shape is preferably used depending on the order (scale, scale) of the size to be calibrated.

For example, in probe shape correction, it is necessary to accurately acquire the shape error of a sphere with a relatively small diameter. Therefore, the prototype 901 uses a spherical prototype with a relatively small diameter as the first prototype for probe calibration. Use.

Further, in the XZ orthogonality correction, since it is necessary to accurately acquire the shape error of the entire scanning range with respect to the relatively large XZ axis, the prototype 901 is relatively used as the second prototype for stage orthogonality calibration. Use a large-diameter spherical prototype.

Although FIG. 17 shows a convex prototype 901, the measurement surface may be a concave surface as long as it has a known curved surface shape). Further, the shape of the prototype 901 may be any shape as long as it is a known curved surface shape suitable for identifying, calculating, and removing a cubic (asymmetric) component corresponding to the XZ-axis stage orthogonality described later. .. As such a curved surface shape, various conic sections (quadric surfaces) such as a spherical surface and an elliptical cross section can be considered. The shape of the prototype 901 is obtained in advance by an inversion method or the like, and the shape data is stored in ROM 1602, HDD 1604, or the like. The prototype 901 is arranged on the main body surface plate 101 via an appropriate jig or the like.

In the probe shape correction and the XZ orthogonality correction, the entire prototype 901 of different sizes as described above is measured by the same probe 108 as the one for measuring the work mounted on the Z-axis stage slider 107.

18 and 19 show the data flow when acquiring the correction data for the probe shape correction and the correction data for the XZ orthogonality, respectively.

In the probe shape correction of FIG. 18, the probe 108 mounted on the Z-axis stage slider 107 is moved and scanned in the X-axis direction by the X-axis stage guide 105. For example, the measurement is started by transmitting the sequence data for measuring the shape of the prototype 901 to the driver of each stage of the shape measuring device 100 via the electrical rack 122. At this time, the shape data of the prototype 901 that moves up and down according to the surface shape of the prototype 901 is input via the electrical rack 122 (601). This shape data is obtained from, for example, a combination of the scale output value of the X-axis coordinate input from the X-axis scale (114, 116) and the scale output value of the Z-axis coordinate input from the Z-axis scale 1071 in synchronization with this. Become. However, at this stage, each coordinate value (scale output value) representing the input shape data (601) of the prototype 901 is uncorrected. FIG. 7 shows the waveform (2101) of the shape data (601) of the prototype 901 in the uncorrected state input from the scale of each XY axis.

When this shape measurement is completed, the CPU 1601 executes the probe shape correction value calculation (1001) for calculating the probe shape correction value. The basis of this probe shape correction value calculation (1001) is, for example, to calculate the probe shape correction data as the difference between the shape data of the prototype 901 stored in advance and the shape data (601) input from the scale of each axis of XY. It is an operation. At this time, as a matter of course, the XY coordinate value (scale) expressing the shape data (601) by the X-axis scale correction value and the Z-axis scale correction value previously stored in the storage unit (304, 404) as described above. Output value) is corrected. Further, the XZ coordinate value (scale output value) expressing the shape data (601) is corrected by the X-axis stage run correction data and the Z-axis stage run correction data stored in advance in the storage units (603, 804). The correction of these XZ scale output values is a coordinate transformation of the two-dimensional coordinate values by each correction data, and the order of these correction processes is arbitrary.

The probe shape correction data can be calculated using the shape data of the prototype 901 through the above-mentioned XZ-axis scale and XZ-axis stage run correction. At this time, as described above, when calculating the probe shape correction data as the difference between the shape data of the prototype 901 stored in advance and the shape data (601) of the prototype 901, curve complementation (least squares method, etc.) is performed. Do. At that time, as described above, from the function expressing the curve-complemented waveform, it corresponds to the XZ-axis orthogonal error component of the XZ-axis stage (scanning system) acting on the shape data (or probe shape correction data) 3 Remove the following components.

The cubic component (or the target component based on the center of the waveform, or the component of the odd function) to be removed from the function representing the curve-complemented waveform is the XZ-axis stage (first and second stages). It may be considered as an error component corresponding to the theoretical value of the orthogonality error of.

For example, the waveform (2101) of the shape data (601) of the prototype 901 in the uncorrected state of FIG. 7 includes the XZ of the XZ-axis stage of the third-order component (third-order waveform) as in the waveform (2201) of FIG. The axis orthogonal error components are superimposed. Therefore, the XZ-axis orthogonal error component of the third-order component (third-order waveform) such as the waveform (2201) of FIG. 8 is removed from the waveform (2101) of the shape data (601) of the prototype 901 of FIG. As a result, as shown in the waveform (2203) of FIG. 9, probe shape correction data in which the influence of the XZ-axis orthogonal error component is suppressed can be acquired.

As described above, the third-order component corresponding to the uncorrected XZ-axis orthogonal error component acting on the probe shape correction data measurement was removed by using only the mathematical process (or the arithmetic processing by the computer). , Highly accurate probe shape correction data can be acquired. The probe shape correction data calculated and acquired by the probe shape correction calculation (1001) is stored in the probe shape correction data storage unit 1002.

FIG. 19 shows a data flow when measuring orthogonality correction data for the X-axis and the Z-axis. In FIG. 19, the arrangement of data flows shown by blocks is close to that of FIG. The difference between FIGS. 18 and 19 is XZ orthogonal using the probe shape correction data generated as shown in FIG. 18 in the XZ orthogonality correction value calculation (1101) and stored in the probe shape correction data storage unit 1002. The point is to calculate the degree correction data.

In the correction of the orthogonality of the X and Z axes in FIG. 19, as described above, the size and shape of the prototype 901 are preferably different from those of the probe shape correction, and are suitable for the correction of the orthogonality of the XZ axis. The shape data of the prototype 901 used for the XZ-axis orthogonality correction is also stored in advance at a predetermined address of the above-mentioned RAM 1603, HDD 1604 or a virtual storage area composed of these.

The measurement procedure of the prototype 901 is the same as that in FIG. 18, and sequence data for measuring the shape of the prototype 901 is transmitted to the driver of each stage of the shape measuring device 100 via the electrical rack 122. As a result, the orthogonality correction measurement process for the X-axis and the Z-axis is started. When the measurement is completed, the prototype measurement data is input (601) via the electrical rack 122.

The basis of this XZ orthogonality correction value calculation (1101) is, for example, the shape data of the prototype 901 (for XZ orthogonality correction) stored in advance and the shape data (601) input from the scale of each XY axis. This is an operation for calculating XZ orthogonality correction data as a difference.

In this XZ orthogonality correction value calculation (1101), the X, Z-axis scale correction values (304, 404), X, Z-axis stage running stored in each storage unit are the same as in the correction data acquisition process of FIG. The correction data (603, 804) is used.

Further, in this XZ orthogonality correction value calculation (1101), the XZ orthogonality correction data is corrected by using the probe shape correction data stored in the probe shape correction data storage unit 1002 as described above. That is, as described above, the XZ orthogonality correction value calculation (1101) is performed using highly accurate probe shape correction data in which the cubic component corresponding to the uncorrected XZ-axis orthogonal error component is removed by a mathematical process. to correct. As a result, it is possible to acquire XZ orthogonality correction data that is not affected by the probe shape error. The XZ orthogonality correction data calculated and acquired by the above-mentioned XZ orthogonality correction value calculation (1101) is stored in the XZ orthogonality correction value data storage unit 1102.

FIG. 20 shows each correction data stored in each storage unit (304, 404, 603, 804, 1002, 1102) after the calibration process of the shape measuring device 100 including each correction process shown in FIGS. 10 to 19. The data flow when measuring the shape of the work using it is shown.

In FIG. 20, 601 shows a work measurement data input process for inputting shape data of the object 109. The state of the shape measuring device 100 at the time of measuring the shape of the object 109 corresponds to the state shown in FIG.

In the measurement of the object 109, the probe 108 mounted on the Z-axis stage slider 107 is moved and scanned in the X-axis direction by the X-axis stage guide 105, as in the case of the measurement of each prototype described above. At this time, the measurement of the work shape is started by transmitting the sequence data for measuring the shape of the object 109 to the driver of each stage of the shape measuring device 100 via the electrical rack 122. At this time, the scale output values of the X-axis scales (114, 116) and the X-axis scales 1071 input from the Z-axis scale 1071 are uncorrected according to the shape of the object 109.

Based on the input (601) (uncorrected) shape data, the CPU 1601 executes the work shape calculation (1201). The shape data to be acquired by the work shape calculation (1201) is, for example, the scale output value of the X and Z axis coordinates input synchronously from the X axis scale (114, 116) and the Z axis scale 1071, respectively. It is a sequence of coordinates (X, Z) obtained by correcting.

In the work shape calculation (1201), the CPU 1601 refers to each correction data stored in each of the above storage units (304, 404, 603, 804, 1002, 1102). For example, at this time, first, the X and Z axis scale correction values (304, 404) and the X and Z axis stage running correction data (603, 804) are used to output the X and Z axis scale values. To correct. Then, the probe shape correction data stored in the probe shape correction data storage unit 1002 and the XZ orthogonality correction data stored in the XZ orthogonality correction value data storage unit 1102 in the correction processing of FIGS. 18 and 19 are allowed to act to form a final result. The shape data of the target object 109 is acquired.

As described above, the work shape measurement result output (1202) can be obtained by the CPU 1601 executing the work shape calculation (1201). The work shape measurement result (1202) can be used for output processing such as display and printing using a display or a printer connected to the measurement control device 123 or the measurement data processing device 124. Further, the work shape measurement result (1202) can be transmitted (output) to a processing or assembling device or a management server via a network (not shown) or the like. In this work shape measurement result (1202), for example, the work shape measurement result calculated by the work shape calculation unit 1201 can be displayed (printed) and output in a numerical list format or a graphic display format corresponding to the numerical list format. it can. If necessary, a voice synthesizing means, a voice synthesizing means, or the like may be used to output the work shape measurement result (1202).

FIG. 3 shows the flow of the entire calibration process of the shape measuring device 100. 4 and 5 show the main parts of the calibration process of FIG. 3, that is, the flow of the probe shape correction process and the XZ axis orthogonality correction process, respectively. Further, FIG. 6 shows the flow of the shape measurement process of the object 109 performed after the calibration process of the shape measuring device 100 is completed. The setting state of the shape measuring device 100 at the time of the probe shape correction process of FIGS. 4 and 5 and the XZ axis orthogonality correction process is as shown in FIG. The data flows in the probe shape correction process and the XZ axis orthogonality correction process of FIGS. 4 and 5 correspond to FIGS. 18 and 19, respectively. The state of the shape measuring device 100 at the time of the shape measuring process of the object 109 of FIG. 6 corresponds to FIG. 1, and the data flow at that time corresponds to FIG. 20. The control procedure of FIGS. 3 to 6 is executed by the control system shown in FIG. 2, particularly the CPU 1601. The control procedure of FIGS. 3 to 6 can be stored in, for example, ROM 1602 or HDD 1604.

In the calibration process of the shape measuring device 100 of FIG. 3, the main body of control, for example, the CPU 1601, first executes the X-axis scale correction process (S1301) and the Z-axis scale correction process (S1302). At this time, the setting state of the shape measuring device 100 is, for example, as shown in FIG. 10, and the data flows during the X-axis scale correction process (S1301) and the Z-axis scale correction process (S1302) are shown in FIG. 11, respectively. , As shown in FIG. The order of the X-axis scale correction process (S1301) and the Z-axis scale correction process (S1302) does not have to be the order shown in FIG. 3, and the order of both may be reversed.

Next, the CPU 1601 executes the X-axis stage run correction process (S1303) and the Z-axis stage run correction process (S1304). At this time, the setting states of the shape measuring device 100 are as shown in FIGS. 13 and 15, respectively, and the data flow during the X-axis stage run correction process (S1303) and the Z-axis stage run correction process (S1304). Are as shown in FIGS. 14 and 16, respectively. The order of the X-axis stage run correction process (S1303) and the Z-axis stage run correction process (S1304) does not have to be the order shown in FIG. 3, and the order of both may be reversed.

Next, the CPU 1601 executes the probe shape correction process (S1305). At this time, the setting states of the shape measuring device 100 are as shown in FIG. 17, and the data flow at that time is as shown in FIG. The probe shape correction process (S1305) and the prototype 901 used in the following XZ orthogonality correction process (S1306) may be common, but if a shape and size suitable for each measurement / correction are used. Good. For example, as described above, in the probe shape correction process (S1305), the diameter of the spherical surface (quadric surface) is relatively small, and in the XZ orthogonality correction process (S1306), the diameter of the spherical surface (quadric surface). Use one with a relatively large overall size.

Here, the details of the probe shape correction process (S1305 in FIG. 3) will be described with reference to FIG. At this time, the state of the shape measuring device 100 is as shown in FIG. 17, and the prototype 901 for measuring the probe shape is measured.

In the probe shape correction process of FIG. 4, first, in the setting data reading process (S1801), various setting data for measurement are read. These are the X and Z axis scale correction values (304, 404) and the X and Z axis stage running correction data (603 and 804) stored in the respective storage units (304, 404, 603 and 804) of FIG.

Next, the CPU 1601 moves the X-axis stage slider 121 to the measurement start position (measurement start position X-axis movement process: S1802). Subsequently, in the Z-axis lowering touchdown process (S1803), the Z-axis stage slider 107 is lowered to bring the probe 108 into contact with the prototype 901. Whether or not the probe 108 has come into contact with the prototype 901 is detected by a displacement sensor (not shown). The CPU 1601 controls the Z-axis stage slider 107 so that the output of the displacement sensor becomes constant.

Next, the CPU 1601 executes the X-axis movement process (S1804). The CPU 1601 transmits sequence data to each part via the electrical rack 122, commands the X-axis driver to move the X-axis stage slider 121 to the measurement end position in the X-axis direction, and causes the X-axis stage slider 121 to move to the X-axis. Move in the direction. As a result, the X-axis stage slider 121 is moved in the X-axis direction while the tip of the probe 108 and the surface of the prototype 901 are kept in contact with each other.

A displacement sensor that executes shape data reading processing (S1805) at the same time as this X-axis scanning and measures the displacements of the X-axis scales (114, 116), Z-axis scales (1071), and probe 108 via the electrical rack 122. Read the output data (not shown). Completion of X-axis movement In the XZ origin return processing (S1806), the movement of the X-axis stage slider 121 is completed, and the X-axis and Z-axis stage sliders are returned to the same origin as at the start of scanning.

Note that steps S1801 to S1806 (S1805 in a narrow sense) in FIG. 4 constitute a first measurement step for acquiring shape data of the prototype 901 via the position information of the probe 108. In this first measurement step, the first prototype 901 for probe calibration is used as an object, and the prototype 901 and the probe 108 are relatively moved by the X-axis stage (first stage). Then, the shape data of the prototype 901 is acquired via the position information of the probe 108.

Subsequently, the CPU 1601 calculates the probe shape correction value in the probe shape calculation process (S1807). The data flow of this probe shape calculation process (S1807) is as shown in FIG. 18, where the scale correction data (304, 404) on the X and Z axes and the stage run correction data (603, 804) on the X and Z axes are used. ) Is used to calculate the probe shape correction data.

At this point, since the XZ orthogonality correction process has not been performed yet, the orthogonality error of the XZ axis stage is included in the measurement data as described above. That is, as shown in FIG. 7, the waveform (2101) of the shape data (601) of the prototype 901 in the uncorrected state includes the XZ axis of the third-order component (third-order waveform) as in the waveform (2201) of FIG. The XZ-axis orthogonal error components of the stage are superimposed. It is known that the XZ orthogonality error as shown in FIG. 8 has a characteristic of a third-order waveform called a top or the like. If the component of the XZ-axis orthogonality error cannot be corrected (removed), accurate probe shape correction data cannot be obtained.

Therefore, as described above, the process of removing (subtracting) the XZ orthogonality error from the measurement data of the probe shape calculation process is performed.

Here, the relationship between the probe shape correction data and the XZ orthogonality error can be expressed by, for example, the following equation (1).

ここで、Ｚ（ｘ）は測定データ、Ｙ（ｘ）はプローブ形状補正用データを示す。また、ｅ（ｘ）は上記のＸＺ直交度誤差に相当する。ここで、接触式のプローブと、形状測定装置１００のようなＸＺ直交走査系を用いて球面（２次曲面）のような形状測定を行うことを考える。この場合、ＸＺ直交度誤差は、対象物の中心の左右に相当する象限において右上りまたは右下りに相当する奇数次（特に３次以下）例えば、このＸＺ直交度誤差は、以下の式（２）のように表現できる。

Here, Z (x) indicates measurement data, and Y (x) indicates probe shape correction data. Further, e (x) corresponds to the above-mentioned XZ orthogonality error. Here, consider performing shape measurement such as a spherical surface (quadric surface) using a contact-type probe and an XZ orthogonal scanning system such as the shape measuring device 100. In this case, the XZ orthogonality error is an odd-numbered order (especially a third order or less) corresponding to the upper right or the lower right in the quadrant corresponding to the left and right of the center of the object. ) Can be expressed as.

ここで上式（２）中のａ_３、ａは、ＸＺ直交度誤差に相当する３次以下の奇数次項の係数で、対象のハードウェアに特有のＸＺ直交度誤差に見合った大きさを有する。式（２）のような関数で表現される誤差波形は、図８のようなＸＺ直交度誤差波形に相当する。

Here a _3, a in the above formula (2), the a factor of third order or less odd-order terms corresponding to the XZ orthogonality error, has a size commensurate with the XZ perpendicularity error specific to the target hardware .. The error waveform represented by the function as shown in equation (2) corresponds to the XZ orthogonality error waveform as shown in FIG.

The size of a _3, a in the above formula (2), for example, a minimum of decomposition coefficients X by the waveform, measured shape waveform by Z scale (Z (x)) in the polynomial as shown in Figure 7 It can be identified by finding it by the square method or the like. For example, when the shape waveform (Z (x)) is decomposed into polynomials,

のように表現することができる。

It can be expressed as.

Here, the XZ orthogonality error (e (x): equation (2), FIG. 8) considers an odd-numbered term of the third order or less, that is, an asymmetric component of the third order or less as the XZ orthogonality error when displayed in a graph. ing. However, the portion of the higher-order asymmetric component of the above equation (3) can also be identified as being included in the XZ orthogonality error (e (x)). Alternatively, more simply, only the cubic term that acts most strongly may be extracted as the XZ orthogonality error e (x). Further, as a polynomial for identifying the shape waveform (Z (X)), a Zernike polynomial or the like may be used.

By removing the XZ orthogonality error e (x) component from the Z (x) (= measurement data) of the equation (1) in this way, the object 109 for probe shape correction is performed without performing the actual measurement process. Accurate probe shape correction data can be obtained by using a mathematical process only by scanning. Thus, the shape waveform (or its error waveform) measured by the X and Z scales as the waveform as shown in FIG. 7 can be corrected to the probe shape waveform (or its error correction data waveform) as shown in FIG.

When the probe shape processing (S1807) of FIG. 4 is completed, the CPU 1601 stores the probe shape correction value in the probe shape correction data storage unit (FIG. 18: 1002) in the probe shape correction value storage process (S1808). As described above, the probe shape correction (acquisition of probe shape correction data) process is completed. Steps S1807 to S1808 (S1807 in a narrow sense) of FIG. 4 constitute a probe shape correction data acquisition step for acquiring 108 shape correction data of the probe based on the measurement of the first measurement step (for example, S1805). In this probe shape correction data acquisition step, an error component corresponding to the theoretical value of the orthogonality error of the (first and second) X and Z axis stages is removed from the shape data of the first prototype 901. Then, the shape correction data of the probe 108 is acquired based on the data obtained by removing the theoretical value of the orthogonality error and the known shape data of the first prototype.

Again, in FIG. 3, when the probe shape correction process (S1305) is completed as described above, the CPU 1601 executes the XZ orthogonality correction process (S1306). The state of the shape measuring device 100 at this time is the same as that shown in FIG. 17, but preferably, the prototype 901 has a curvature as much as possible for the XZ orthogonality correction, unlike the one for the probe shape correction. Use a prototype that is large and has a large sag. That is, for the XZ orthogonality correction, a prototype with a large X-axis movement amount and a Z-axis movement amount when the shape is traced by the probe 108 is suitable.

Here, the details of the XZ orthogonality correction process (S1306 in FIG. 3) will be described with reference to FIG.

In FIG. 5, the CPU 1601 first performs a setting data reading process (S1901), and reads various setting data for measurement. These are the X, Z-axis scale correction values (304, 404), X, Z-axis stage running correction data (603, 804) stored in each storage unit (304, 404, 603, 804, 1002) of FIG. And probe shape correction data (1002).

Next, the CPU 1601 moves the X-axis stage slider 121 to the measurement start position (measurement start position X-axis movement process: S1902). Subsequently, in the Z-axis lowering touchdown process (S1903), the Z-axis stage slider 107 is lowered to bring the probe 108 into contact with the prototype 901. As in the case of FIG. 4, thereafter, the Z-axis stage slider 107 is controlled by using a displacement sensor (not shown) that detects the displacement of the probe 108. For example, the CPU 1601 controls the Z-axis stage slider 107 so that the output of the displacement sensor becomes constant.

Next, the CPU 1601 executes the X-axis movement process (S1904). The CPU 1601 transmits sequence data to each part via the electrical rack 122, commands the X-axis driver to move the X-axis stage slider 121 to the measurement end position in the X-axis direction, and causes the X-axis stage slider 121 to move to the X-axis. Move in the direction. As a result, the X-axis stage slider 121 is moved in the X-axis direction while the tip of the probe 108 and the surface of the prototype 901 are kept in contact with each other.

At the same time as this X-axis scanning, the CPU 1601 reads output data from the measuring means of each part via the electrical rack 122 in the shape data reading process (S1905). Here, for example, the output data of the displacement sensor (not shown) for measuring the displacement of the X-axis scale (114, 116), the Z-axis scale 1071, and the probe 108 is read. When the desired X-axis scanning is completed, the movement of the X-axis stage slider 121 is completed in the X-axis movement complete XZ origin return processing (S1906), and the stage sliders of the X and Z axes are set to the same origin as at the start of scanning. return.

Note that steps S1901 to S1906 (S1905 in a narrow sense) in FIG. 5 constitute a second measurement step for acquiring shape data of the second prototype 901 via the position information of the probe 108. In this second measurement step, a second prototype 901 for stage orthogonality calibration is used as an object, and the prototype 901 and the probe 108 are relatively moved by the X-axis stage (first stage). Then, the shape data of the prototype 901 is acquired via the position information of the probe 108.

Subsequently, the CPU 1601 calculates the XZ orthogonality correction value in the XZ orthogonality correction calculation process (S1907). The data flow of this XZ orthogonality correction calculation process (S1907) is as shown in FIG. 19, where the X and Z axis scale correction data (304 and 404) and the X and Z axis stage run correction data (603 and 804). ) Calculate the XZ orthogonality correction data. Further, in this XZ orthogonality correction calculation process (S1907), the shape of the probe shape correction data (1002) probe is also corrected. At this stage, the probe shape correction has already been completed, the probe shape error can be removed, and accurate XZ orthogonality correction data can be obtained. When the XZ orthogonality correction calculation process (S1907) is completed, the calculated XZ orthogonality correction data in the XZ orthogonality correction value storage process (S1908) is stored in the XZ orthogonality correction value data storage unit (FIG. 19: 1102). To do.

Steps S1907 to S1908 (S1907 in a narrow sense) of FIG. 5 constitute an orthogonality correction data acquisition step for acquiring orthogonality correction data of the X and Z axis (first and second) stages. In this orthogonality correction data acquisition step, the shape correction data of the probe 108 obtained in the probe shape correction data acquisition step, the known shape data of the second prototype 901, and the second measurement step were obtained. The shape data of the second prototype is used.

As a result, the orthogonality correction of the XZ axis is completed, and all the calibration processing of the shape measuring device 100 of FIG. 3 is completed. In the calibration process of the shape measuring device 100 shown in FIG. 3, a correction process for additionally correcting the curvature error of the probe may be executed. Further, when a prototype or a turntable for rotating a work is arranged on the main body surface plate 101, a correction process for correcting the rotation accuracy of such a rotating means may be performed.

Next, with reference to FIG. 6, a control procedure for measuring the shape of the object 109 after the calibration process of FIG. 3 is completed will be described. In this "production" shape measurement, the main body of control is, for example, the control system shown in FIG. 2, the measurement control device 123, and the CPU 1601 of the measurement data processing device 124. In the above, the control of the calibration process has been described assuming a control system in which the measurement control device 123 and the measurement data processing device 124 are virtually integrated, for example. However, in the process of FIG. 6, the measurement control device 123 and the measurement data processing device 124 are provided separately, and it is shown that the shape measurement control can be executed by their cooperation. However, it goes without saying that the processing of FIG. 6 can be performed even in a system provided with one control system in which the functions of the measurement control device 123 and the measurement data processing device 124 are integrated.

The shape measurement control of FIG. 6 is started when the operator sets the object 109, which is the object, on the tilt stage 110, and performs a specific operation for instructing the start of measurement, for example, by the measurement data processing device 124.

In the setting data reading process (S2001) of FIG. 6, various setting data and parameters of the object 109 are read. Here, for example, the design data of the object 109, various setting data such as the measurement range and the moving speed, and parameter data are acquired via the measurement data processing device 124.

In the moving data output process (S2002), for example, the measurement data processing device 124 generates various setting data read in the setting data reading process (S2001) and sequence data of each part of the shape measuring device 100 based on the parameters. For example, control data of the X-axis stage slider 121 and the Z-axis stage slider 107 required for shape measurement control of the object 109 is generated. The generated sequence data is transmitted to the measurement control device 123.

In the Z-axis origin setting drive process (S2003), the measurement control device 123 commands the Z-axis driver of the electrical rack 122 to move the Z-axis stage slider 107 to the origin.

In the measurement start position X-axis movement process (S2004), the measurement control device 123 commands the X-axis driver of the electrical rack 122 to move the X-axis stage slider 121 supported by the X-axis stage guide 105 to the X-axis start position. To do. As a result, the X-axis stage slider 121 is moved to the X coordinate for starting the measurement of the object 109. When the X-axis movement is completed, the Z-axis lowering and work touchdown processing (S2005) are executed next.

The measurement control device 123 commands the Z-axis driver for driving the Z-axis stage slider 107 to descend, and brings the probe 108 into contact with the surface of the object 109. The measurement control device 123 detects that the contactor at the tip of the probe 108 has come into contact with the surface of the object 109 due to the lowering of the Z-axis stage slider 107 via a displacement sensor (not shown) arranged on the probe 108. After that, the Z-axis stage slider 107 is controlled so that the output from the displacement sensor (not shown) becomes constant.

When the Z-axis lowering and work touchdown processing (S2005) are completed, the process proceeds to the measurement end position X-axis moving processing (S2006). In this measurement end position X-axis movement process (S2006), the measurement control device 123 instructs the X-axis driver of the electrical rack 122 to move the X-axis stage slider 121 to the measurement end position in the X-axis direction, and the X-axis stage The slider 121 is moved in the X-axis direction. At this time, the X-axis stage slider 121 is moved in the X-axis direction while tracing the surface of the object 109 with the probe 108. During this time, the Z-axis stage slider 107 is controlled so that the output from the displacement sensor (not shown) becomes substantially constant. Further, the position data of the X-axis stage slider 121 with respect to the first X-axis scale 114 is read from the first X-axis scale head 117. At the same time, the position data of the X-axis stage slider 121 with respect to the second X-axis scale 116 is read from the second X-axis scale head 119. At the same time, the Z-axis position data of the Z-axis stage slider 107 is read from the Z-axis scale 1071, and the Z-axis position data of the probe 108 is read from the displacement sensor (not shown) of the probe 108. The data of each scale and displacement sensor is transferred to the measurement control device 123 via the electrical rack 122.

When the measurement end position X-axis movement process (S2006) is completed, in the Z-axis ascent process (S2007), the measurement control device 123 transmits sequence data for ascending the Z-axis stage slider 107 via the electrical rack 122. As a result, the probe 108 is separated from the object 109.

In the data transfer process (S2008), the data of each scale and displacement sensor captured during the process of the measurement end position X-axis movement process (S2006) is transferred from the measurement control device 123 to the measurement data processing device 124.

As described above, the moving locus coordinates of the probe 108 can be captured while moving the probe 108 following the surface of the object 109.

When the data transfer process (S2008) is completed, the process proceeds to the system error correction process (S2009) for correcting the system error using various correction data generated in the above calibration process. In this system error processing (S2009), the system error correction data generated in the above-mentioned calibration processing is used, and correction processing is performed on the scale data of each axis of XZ and the displacement sensor captured by the data transfer (S2008).

This system error correction process (S2009) corresponds to the work shape calculation (S1201) in the data flow of FIG. In this system error correction process (S2009), the X-axis and Z-axis scale corrections are performed using the data of the X-axis scale correction data storage unit 304 and the Z-axis scale correction data storage unit 404. Further, the X-axis and Z-axis stage run corrections are performed using the data of the X-axis stage run correction data storage unit 603 and the Z-axis stage run correction data storage unit 802. Further, the probe shape is corrected by the data of the probe shape correction data storage unit 1002, and the orthogonality of the XZ axis is corrected by the data of the XZ orthogonality correction value data storage unit 1102. However, among these correction processes, it is not necessary to execute a process that does not require correction according to the design specifications of the device, the control specifications, the specifications of the object 109, and the like.

Subsequently, in the fitting calculation process (S2010), the surface shape data of the object 109 is generated from each data (or each data not corrected) corrected by the system error correction process (S2009). Further, in the fitting calculation process (S2010), the accurate position of the object 109 is calculated from the design shape data of the object 109. At this stage, for example, the position of the object 109 cannot be specified only by mounting the object 109 on the tilt stage 110. Therefore, it is assumed that the object exists at the position assumed in advance, and the design shape data is arranged at that position. Then, the surface shape measurement data of the object 109 and the design shape data arranged on the tilt stage 110 are compared, and the surface shape data movement position of the object whose difference is minimized is calculated by using the least squares method or the like. In the case of the least squares method, for example, the surface shape that minimizes the sum of squares of the difference between the surface shape measurement data and the surface shape design data using the least squares method from the coordinate conversion formula that translates and rotates the surface shape measurement data. Find the translation and rotational movement positions of the data.

Subsequently, in the shape measurement of FIG. 6, the shape error of the object 109 is obtained. That is, the shape error of the object 109 can be obtained as the difference between the design shape data and the measured shape data of the object 109 whose fitting error has been corrected by the shape error calculation process (S2011).

Finally, in the measurement result display (S2012), the error shape from the design value of the object 109 calculated by the shape error calculation process (S2011) is output as a numerical value or a graph. It is also possible to compare the error shape of the object 109 with a numerical value stored in advance as a standard value of the object 109 and display the quality determination result of the object 109. A display or the like provided in the measurement data processing device 124 can be used for the measurement result display (S2012). However, for this measurement result display (S2012), not only the display output but also a print output using a printer or the like, or an output method such as an audio output may be used if necessary.

As described above, according to the present embodiment, prior to the XZ orthogonality error correction, only the scanning of the object 109 for the probe shape correction is mathematically performed without performing the actual measurement processing at the time of the probe shape correction calculation. Accurate probe shape correction data can be obtained using the process. Therefore, in the subsequent XZ orthogonality error correction, the probe shape correction can be applied to acquire accurate XZ orthogonality error correction data. In this way, in the system error calibration process of the shape measuring device 100, the probe shape correction and subsequently the XZ orthogonality error correction can be accurately realized. Therefore, according to this embodiment, it is possible to accurately obtain all the corrections in the end, so that the shape measurement of the object 109 can be performed with high accuracy. For example, the shape measuring device (FIG. 1) of this embodiment is used to perform a system error calibration process (FIG. 3) and then a shape measurement process (FIG. 6) to accurately measure the surface shape of the object 109. can do. The object 109 whose shape is to be measured includes, for example, an object such as an optical element represented by a lens made of an aspherical surface, a spherical surface, or the like, such as a work in the process of processing or assembling, or a work in which they are completed. Similar structures are conceivable.

The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. But it is feasible. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

100 ... Shape measuring device, 101 ... Main body platen, 102 ... Vibration isolation table, 103 ... Stand, 104 ... Frame, 105 ... X-axis stage guide, 106 ... Z-axis stage guide, 107 ... Z-axis stage slider, 108 ... Probe , 109 ... Object, 110 ... Tilt stage, 111 ... XY stage, 112 ... θ rotation stage, 114, 116 ... X-axis scale, 117, 119 ... Scale head, 118 ... X-axis scale head frame, 120 ... X-axis scale Head frame, 121 ... X-axis stage slider, 122 ... Electrical rack, 123 ... Measurement control device, 124 ... Measurement data processing device, 201 ... Target, 202 ... Bender mirror, 203, 204 ... Laser length measuring device, 501 ... Planar original Instrument, 701 ... displacement sensor, 901, 702 ... prototype, 1601 ... CPU, 1602 ... ROM, 1603 ... RAM, 1604 ... HDD, 1605 ... display, 1606 ... keyboard, 1607, 1608 ... interface.

Claims (18)

The probe in a second direction supported by the first stage and orthogonal to the first stage, and a first stage for relatively moving the object of shape measurement and the contact probe in the first direction. A second stage for movably supporting the probe, a first scale for detecting relative position information of the object and the probe in the first direction, and position information of the probe in the second direction. With a second scale for detecting the object and the probe in contact with the surface of the object, the object and the probe are relatively moved by the first stage, and at that time, the first. The position information regarding the first direction of the object detected via the scale of the above, and the movement along the second direction according to the surface shape of the object detected via the second scale. In the shape measuring method of the shape measuring device for measuring the shape data of the object based on the position information regarding the second direction of the probe.
The position of the probe obtained by the control device using a first prototype for probe calibration having a known curved surface shape as the object and relatively moving the object and the probe by the first stage. The first measurement step of acquiring the shape data of the first prototype via information, and
Wherein the controller, from said first measurement the shape data of the first prototype which was obtained in step, as an error component corresponding to the theoretical value of orthogonality error of the first and second stages, the first Shape correction data of the probe based on the shape data obtained by removing the tertiary component of the shape data of the first prototype obtained in the measurement step 1 and the known shape data of the first prototype. The probe shape correction data acquisition step to acquire
A method for measuring the shape of a shape measuring device provided with. The method for measuring the shape of the shape measuring device according to claim 1, wherein the first prototype has a quadric surface shape. In the shape measuring method of the shape measuring device according to claim 1 or 2, after the probe shape correction data acquisition step,
As the object, the control device uses a second prototype for stage orthogonality calibration having a known curved shape different from that of the first prototype, and the object and the object are subjected to the first stage. A second measurement step of acquiring shape data of the second prototype via the position information of the probe obtained by relatively moving the probe, and
The control device obtains the shape correction data of the probe in the probe shape correction data acquisition step, the known shape data of the second prototype, and the second source obtained in the second measurement step. An orthogonality correction data acquisition step for acquiring the orthogonality correction data of the first and second stages based on the shape data of the vessel, and
A method for measuring the shape of a shape measuring device provided with. The method for measuring the shape of the shape measuring device according to claim 3, wherein the second prototype has a quadric surface shape. In the shape measuring method of the shape measuring device according to any one of claims 1 to 4 , the control device performs the first or second method prior to the first measuring step and the probe shape correction data acquisition step. A method of measuring the shape of a shape measuring device including a stage running correction data acquisition step for acquiring running correction data of the scale of. In the shape measuring method of the shape measuring device according to claim 5 , the scale linearity correction in which the control device acquires the linearity correction data of the first or second scale prior to the stage running correction data acquisition step. A shape measuring method for a shape measuring device including a data acquisition step. In the shape measuring method of the shape measuring device according to any one of claims 1 to 6, the object is subjected to the first stage in a state where the control device is in contact with the surface of the object. And the probe is relatively moved, and at that time, the position information regarding the first direction of the object detected via the first scale and the surface shape of the object detected via the second scale. The object is based on the position information regarding the second direction of the probe that moves along the second direction according to the above and the shape correction data of the probe acquired in the probe shape correction data acquisition step. A shape measuring method of a shape measuring device including a shape calculation step for calculating shape data. In the shape measuring method of the shape measuring device according to any one of claims 1 to 7, the cubic component of the shape data of the first prototype is a curve of the shape data of the first prototype. A method for measuring the shape of a shape measuring device, which is a cubic component of a function representing a complemented curve . A control program for a shape measuring device for causing the control device according to any one of claims 1 to 8 to execute each step. A computer-readable recording medium that stores the control program of the shape measuring device according to claim 9. The probe in a second direction supported by the first stage and orthogonal to the first stage, and a first stage for relatively moving the object of shape measurement and the contact probe in the first direction. A second stage for movably supporting the probe, a first scale for detecting relative position information of the object and the probe in the first direction, and position information of the probe in the second direction. With a second scale for detecting the object and the probe in contact with the surface of the object, the object and the probe are relatively moved by the first stage, and at that time, the first. The position information regarding the first direction of the object detected via the scale of the above, and the moving along the second direction according to the surface shape of the object detected via the second scale. In a shape measuring device that measures shape data of the object based on the position information regarding the second direction of the probe.
As the object, a prototype for probe calibration having a known curved surface shape is used, and the object and the probe are relatively moved by the first stage, and the position information of the probe is obtained. from standard of shape data, and shape data wherein as an error component corresponding to the theoretical value of the orthogonality error of the first and second stage, to remove the third order component of the shape data of the acquired standard, the A shape measuring device including a control device that acquires shape correction data of the probe based on known shape data of the prototype. A shape measuring method for acquiring the shape of an object from the shape data of the object measured by contacting a probe with the surface of the object and scanning the object.
A step of scanning the surface of a first prototype whose surface shape is known with the probe and measuring the shape data of the first prototype.
The first correction data is obtained from the shape data obtained by removing the tertiary component of the shape data of the first prototype from the shape data of the first prototype and the known shape data of the first prototype. And the steps to get
Shape measurement method including. In the shape measuring method according to claim 12, the step of scanning the surface of a second prototype whose surface shape is known with the probe and measuring the shape data of the second prototype, and the first step. A shape measuring method further including a step of acquiring a second correction data from the correction data, the known shape data of the second prototype, and the measured shape data of the second prototype. In the shape measuring method according to claim 13, a step of bringing a probe into contact with the surface of an object and scanning the object to acquire shape data of the object, shape data of the object, and the first correction data. A shape measurement method including a step of calculating the shape measurement result of the object from the second correction data and the second correction data. In the shape measuring method according to any one of claims 12 to 14, the cubic component of the shape data of the first prototype is a waveform complemented by a curve of the shape data of the first prototype. A shape measurement method that is a cubic component of a function representing. A data processing method for acquiring the shape of an object from the shape data of the object measured by contacting a probe with the surface of the object and scanning the object.
Shape data obtained by scanning the surface of a first prototype whose surface shape is known with the probe and removing the tertiary component of the shape data of the first prototype from the shape data of the first prototype. A data processing method including a step of correcting the shape data of the object by using the known shape data of the first prototype and the first correction data calculated from the above. In the data processing method according to claim 16, the shape data of the second prototype acquired by scanning the surface of the second prototype whose surface shape is known with the probe, and the first correction data. A data processing method including a step of correcting the shape data of the object by using the known shape data of the second prototype and the second correction data calculated from the data. In the data processing method according to claim 16 or 17, the cubic component of the shape data of the first prototype is a function 3 representing a curve-complemented waveform of the shape data of the first prototype. Data processing method that is the next component.

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