JP6730857B2 - Step height gauge, reference plane measuring method, and reference plane measuring device - Google Patents

Description

The present invention relates to a step height gauge having a reference surface, a reference surface measuring method using the step height gauge, and a reference surface measuring device using the step height gauge.

Conventionally, a measuring device for measuring a minute measuring range, such as a shape measuring device for measuring the shape of an object to be measured or a displacement measuring device for measuring the amount of displacement of a measured part (for example, a capacitance type displacement sensor). Then, a standard end device is used to calibrate a reference plane that is a reference for measurement (see, for example, Patent Document 1).
The device described in Patent Document 1 is an end-probe comparison measuring machine that measures the end-measuring device by comparing the standard end-measuring device and the measured end-measuring device. Place the probe and the holder on the table while holding it in the holder, and make a comparison measurement by contacting the measurement probe with the upper surface of the standard probe and the measured probe.

JP, 2014-52273, A

When the height dimension of the end gauge (block gauge) is measured to calibrate the reference height surface, the block gauge is placed on a table and the upper surface thereof is measured, as described in Patent Document 1 above. Further, when a plurality of height standards are required, a so-called step height gauge is usually used in which block gauges having different height dimensions are arranged in a staircase pattern. In this case, the upper surface of any one of the block gauges of the step height gauge is used as the measurement reference surface, and the height dimension from the measurement reference surface to the upper surface of the other block gauge is measured to obtain the height of each block gauge. Measure the height dimension of the top surface.

However, when the step height gauge is placed on the table, there are cases where the measurement reference surface is inclined, the surface accuracy of the measurement reference surface is low, and the like. In such a case, even if the dimension up to the upper surface of each block gauge is measured with the measurement reference surface as a reference, highly accurate measurement results cannot be obtained.
For example, in a step height gauge including a first block gauge having a first surface and a second block gauge having a second surface, the first surface is used as a measurement reference surface and the dimension from the first surface to the second surface is measured. In that case, first, the first surface is measured, and the least squares plane of the first surface is calculated. Then, a predetermined measurement point on the second surface is measured, and the distance from the measurement point to the first surface (the distance along the normal direction of the least square plane) is calculated. Therefore, when the least square plane of the first surface includes an error due to inclination or the like, an error also occurs in the height dimension of the second surface.
In particular, in recent years, the precision of measuring devices has increased, and even a slight inclination of the reference plane, which has been neglected in the past, has a great influence on the measurement accuracy. Gauges are strongly demanded.

It is an object of the present invention to provide a step height gauge, a reference surface measuring method, and a reference surface measuring device capable of suppressing occurrence of measurement error and performing highly accurate measurement.

The step height gauge of the present invention includes a base having a smooth mounting surface and a plurality of gauge blocks mounted on the mounting surface, and the gauge block is ringed on the mounting surface. A lower surface and a surface opposite to the lower surface, and an upper surface parallel to the lower surface; and the mounting surface has the plurality of gauge blocks arranged in one direction in a plan view seen from a normal direction. A placement area to be placed, a first reference measurement area provided outside the placement area on one side of the one direction and exposed to the outside, and an outside of the placement area on the other side of the one direction. And a second reference measurement region which is provided at the outside and is exposed to the outside.

In the present invention, the gauge blocks are arranged so as to be lined in one direction with respect to the placement area of the placement surface of the base. Then, on the mounting surface of the base, the first reference measurement area and the second reference measurement area are provided outside the one side of the mounting area with the mounting area interposed therebetween. The position coordinates including the position can be measured.
In such a step height gauge, an arbitrary first reference measurement point is set from the first reference measurement area, an arbitrary second reference measurement point is set from the second reference measurement area, and these first reference measurement points are set. Also, by measuring the position coordinates of the second reference measurement point, a straight line (reference straight line) connecting the first reference measurement point and the second reference measurement point can be calculated. Then, by measuring the position coordinates of a predetermined measurement point (block measurement point) on the upper surface of each gauge block, by calculating the distance from the above-mentioned reference straight line to the block measurement point of each gauge block, The height of the upper surface can be calculated accurately.

That is, in the past, the upper surface of one gauge block was used as the measurement reference surface, and the distance between the upper surfaces of the other gauge blocks and the reference block surface was calculated. In this case, however, there is a slight inclination in the measurement reference surface. An error occurs in the height dimension of the upper surface of each gauge block calculated thereafter. In particular, in a gauge block arranged on the mounting surface at a position away from the gauge block that sets the reference block surface, the influence of the error becomes large.
On the other hand, in the present invention, as described above, the first reference measurement area and the second reference measurement area of the base provided at positions sandwiching the plurality of gauge blocks are not the upper surface of one gauge block but the first reference measurement area and the second reference measurement area, respectively. It is possible to set the one reference measurement point and the second reference measurement point, calculate the reference straight line, and measure the height dimension of each gauge block with respect to the reference straight line. Therefore, even if there is a slight inclination on the top surface of each gauge block due to surface accuracy or the state of ringing, if the linear formula of the reference straight line is calculated by the method of least squares, the error due to the inclination is canceled (averaged). ) Therefore, it is possible to measure the height dimension of the upper surface of each gauge block with high accuracy and to calibrate the reference height surface with high accuracy, as compared with the related art.

In the step height gauge of the present invention, a cover that covers a side surface portion that intersects with the mounting surface and that is adhesively fixed to the base and the gauge block is provided, and the cover includes the first reference measurement region and the second reference measurement region. It is preferable to have openings corresponding to the reference measurement area and the placement area.
The step height gauge is usually provided with a cover for the purpose of protecting the base and the gauge block. Such a cover is generally formed so that only the mounting area on which the gauge block is mounted is opened with respect to the mounting surface, but in the present invention, in addition to the mounting area, A portion corresponding to the measurement area provided on the outer circumference is also opened. Accordingly, the position coordinates of the first reference measurement point and the second reference measurement point can be measured from the first reference measurement area and the second reference measurement area, respectively, and the reference straight line as described above can be calculated.
In addition, since the cover is bonded to the base and the gauge block, the gauge block is fixed to the base in a ringing state, and the displacement of the gauge block with respect to the base and the inclination of the upper surface of the gauge block are prevented. Can be suppressed.

The reference surface measuring method of the present invention comprises a base having a smooth mounting surface, and a plurality of gauge blocks mounted on the mounting surface, wherein the plurality of gauge blocks are arranged on the mounting surface. A reference plane measuring method for measuring the height of a reference plane using a step height gauge arranged side by side in the direction, wherein the one direction of the placement area in which the gauge block of the placement surface is placed. The first reference measurement point provided on the outside of the placement area on one side, the position coordinates of the second reference measurement point provided on the outside of the placement area on the other side of the one direction of the placement area. From the position of the reference measurement point obtaining step, the block measurement point obtaining step of obtaining the position coordinates of the block measurement point on the upper surface of the gauge block, the position of the first reference measurement point and the second reference measurement point, A reference calculation step of calculating a reference straight line including the first reference measurement point and the second reference measurement point, and a reference height calculation step of calculating a dimension from the reference straight line to the block measurement point are performed. It is characterized by

In the present invention, for the step height gauge, in the reference measurement point acquisition step, with respect to the arrangement direction (one direction) of the plurality of gauge blocks, the first reference measurement point and the first reference measurement point at the positions sandwiching these gauge blocks are provided. The position coordinates of the two reference measurement points are acquired (measured), and a reference straight line including these first reference measurement point and second reference measurement point is calculated in the reference calculation step. Then, in the block measurement point acquisition step, the position coordinates of a predetermined block measurement point on the upper surface of each gauge block are acquired (measured), and in the reference height calculation step, the distance from the reference straight line to the block measurement point is calculated. ..
Therefore, similar to the above-mentioned invention, even if the upper surface of each gauge block has a slight inclination due to the surface accuracy, the state of ringing, etc., if the linear equation of the reference straight line is calculated by the least square method or the like, an error due to the inclination is generated. It will be canceled, and it becomes possible to measure the height dimension with high accuracy while suppressing the influence of error.

In the reference surface measuring method of the present invention, a block measurement coordinate acquisition step of acquiring the measurement coordinates of the block measurement point with respect to the plan view from the normal direction of the mounting surface is provided, and the reference measurement point acquisition step is the above description. The position coordinates of the block measurement point with respect to the plan view from the normal direction of the placement surface, the position coordinates of the first reference measurement point and the second reference measurement point included on the reference straight line in the plan view is acquired. It is preferable.
In the present invention, the first reference measurement point and the second reference measurement point are set such that the block measurement point is located on the reference straight line in a plan view of the mounting surface as seen from the normal line. Therefore, the height dimension at the desired block measurement point can be accurately measured.

The reference surface measuring device of the present invention includes a base having a smooth mounting surface, and a plurality of gauge blocks mounted on the mounting surface, wherein the plurality of gauge blocks are arranged on the mounting surface. A reference plane measuring device for measuring the height of a reference plane using a step height gauge arranged side by side in the direction, wherein the one direction of the placement area in which the gauge block of the placement surface is placed. The first reference measurement point provided on the outside of the placement area on one side, the position coordinates of the second reference measurement point provided on the outside of the placement area on the other side of the one direction of the placement area. From the position coordinates of the reference measurement point acquisition unit, the block measurement point acquisition unit that acquires the position coordinates of the block measurement point on the upper surface of the gauge block, and the position coordinates of the first reference measurement point and the second reference measurement point A reference calculation unit that calculates a reference straight line including the first reference measurement point and the second reference measurement point; and a height calculation unit that calculates a dimension from the reference straight line to the block measurement point. Is characterized by.
In the present invention, with respect to the step height gauge, the measurement point position acquisition unit determines the first reference measurement point and the first reference measurement point at a position sandwiching these gauge blocks in the arrangement direction (one direction) of the plurality of gauge blocks. The position coordinates of the two reference measurement points are acquired (measured), and the reference calculation unit calculates a reference straight line including the first reference measurement point and the second reference measurement point. Then, the block measurement point acquisition unit acquires (measures) the position coordinates of a predetermined block measurement point on the upper surface of each gauge block, and the height calculation unit calculates the distance from the reference straight line to the block measurement point.
Therefore, similar to the above-mentioned invention, even if the upper surface of each gauge block has a slight inclination due to the surface accuracy, the state of ringing, etc., if the linear equation of the reference straight line is calculated by the least square method or the like, an error due to the inclination is generated. It will be canceled, and it becomes possible to measure the height dimension with high accuracy while suppressing the influence of the error.

According to the present invention, even if a slight inclination due to surface accuracy or ringing state is present on the upper surface of the gauge block, the error due to the inclination is canceled by calculating the linear equation of the reference straight line by the least square method or the like. Therefore, it is possible to perform highly accurate height dimension while suppressing the influence of the error.

1 is a schematic perspective view of a step height gauge according to an embodiment of the present invention. The schematic plan view of the step height gauge of this embodiment. The schematic side view of the step height gauge of this embodiment. The block diagram which shows the schematic structure of the interference measurement apparatus of this embodiment. The flowchart which shows the reference plane measuring method of this embodiment. The schematic plan view for explaining the reference plane measuring method in the present embodiment. The schematic side view for demonstrating the reference plane measuring method in this embodiment. The figure which shows an example of the step height gauge in the modification of this invention.

Hereinafter, an embodiment according to the present invention will be described.
[Structure of step height gauge]
FIG. 1 is a perspective view showing a schematic configuration of a step height gauge of the present embodiment, FIG. 2 is a plan view of the step height gauge viewed from the height direction, and FIG. 3 is a step height gauge. FIG.
The step height gauge 1 is used, for example, for calibration of a height reference plane in various measuring devices such as a three-dimensional measuring device and a position detecting sensor such as a capacitance displacement sensor.

Specifically, as shown in FIGS. 1 to 3, the step height gauge 1 includes a base 11, a plurality of gauge blocks 12, and a cover 13.
The base 11 is formed in, for example, a rectangular parallelepiped, and has at least a bottom surface 111 (see FIGS. 1 and 3) and a mounting surface 112 parallel to the bottom surface 111.
The bottom surface 111 is a flat surface that is placed on a table on which an object to be measured of the measuring device is set.

The mounting surface 112 is formed parallel to the bottom surface 111 so as to be parallel to the upper surface of the table when the bottom surface 111 is mounted on the table of the measuring device, for example. The mounting surface 112 is a surface on which the gauge block 12 is closely fixed (ringing), and is a smooth flat surface.
More specifically, the mounting surface 112 includes a mounting area 112A (see FIGS. 2 and 3) on which the gauge block 12 is ringed, and a first reference measurement area 112B provided outside the mounting area 112A. , And a second reference measurement area 112C that is also provided outside the placement area 112A. In this embodiment, the gauge blocks 12 are arranged on the mounting surface 112 along one direction (X direction in FIGS. 1 to 3), and the first reference measurement region 112B is mounted on the mounting surface 112. The -X side of the placement area 112A and the second reference measurement area 112C are provided on the +X side of the placement area 112A.

As shown in FIGS. 1 to 3, the gauge block 12 is formed in, for example, a rectangular parallelepiped shape, and the lower surface (ringing surface 121; see FIG. 3) contacting the mounting surface 112 and the ringing surface 121 are And an upper surface (block measurement surface 122) on the opposite side. The ringing surface 121 and the block measuring surface 122 are formed as smooth flat surfaces, and the ringing surface 121 is ringed (closely fixed) to the mounting surface 112 of the base 11. Further, the height dimensions from the ringing surface 121 to the block measurement surface 122 of each gauge block 12 are different from each other, and these gauge blocks 12 having different height dimensions are arranged in the mounting area 112A of the mounting surface 112 along the X direction. They are arranged side by side.

By the way, in the gauge block 12, the ringing surface 121 and the block measuring surface 122 are usually highly parallel so that the block measuring surface 122 is parallel to the mounting surface 112 when ringed on the mounting surface 112. Being manufactured. However, in reality, it is difficult to make the ringing surface 121 and the block measurement surface 122 perfectly smooth and parallel to each other due to manufacturing reasons, and when the ringing surface 121 is ringed to the mounting surface 112, the block The measurement surface 122 may be slightly inclined.
In this embodiment, even in such a case, the step height gauge 1 capable of measuring the height dimension of the block measurement surface 122 of each gauge block 12 with high accuracy, and the reference surface using the step height gauge 1 A measuring device and a reference plane measuring method are provided. A detailed description of the reference plane measuring device and the reference plane measuring method will be given later.

The cover 13 is a member that protects the step height gauge 1, and includes a side surface portion 113 (see FIGS. 2 and 3) that intersects the bottom surface 111 of the base 11 and the mounting surface 112, and a part of the mounting surface 112. , Is covered.
Specifically, as shown in FIG. 3, the cover 13 starts from a predetermined height position on the side surface portion 113 slightly closer to the mounting surface 112 than the bottom surface 111, from the mounting area 112A on the mounting surface 112. The range other than the first reference measurement region 112B and the second reference measurement region 112C is covered.
Therefore, as shown in FIGS. 1 and 3, the bottom surface 111 of the base 11 is exposed from the cover 13, and the flat bottom surface 111 can be placed on the table.
Further, the cover 13 has an opening 131 corresponding to the placement area 112A, the first reference measurement area 112B, and the second reference measurement area 112C. As a result, the gauge block 12 can be brought into contact with the mounting area 112A, and the first reference measurement area 112B and the second reference measurement area 112C are exposed so that they can be measured by the measuring device.

The cover 13 is fixed to the side surfaces of the base 11 and the gauge block 12 with a fixing material such as an adhesive. For this reason, the base 11 and the gauge block 12 are fixed through the fixing material and the cover 13 in a state where the gauge block 12 is ringed with respect to the base 11.

[Configuration of reference plane measuring device]
Next, a reference plane measuring device for measuring the step height gauge 1 as described above will be described. In the present embodiment, the interference measuring device 2 is exemplified as the reference plane measuring device.
FIG. 4 is an overall view showing a schematic configuration of the interference measurement device 2.
As shown in FIG. 4, for example, the interference measuring apparatus 2 includes a pedestal portion 21, a table 22 provided on the pedestal portion 21, on which an object to be measured is placed, and an object to be measured placed on the table 22. An optical probe 23 that measures the surface texture, a moving mechanism 24 that moves the optical probe 23, and a control unit 25 that controls the optical probe 23 and the moving mechanism 24 are provided. Although illustration is omitted, an operation unit or the like for the measurement person to set and input predetermined data may be provided.

The table 22 is provided on the pedestal portion 21 and has a flat measurement target mounting surface 22A on which the object to be measured is mounted. When calibrating the height reference plane using the step height gauge 1 described above, the bottom surface 111 of the base 11 is placed on the measurement target placement surface 22A and brought into contact therewith.

Although not specifically shown, the optical probe 23 includes, for example, a light emitting unit, a light separating unit, a light combining unit, a light receiving unit, and the like. In such an optical probe 23, light such as laser light is output from the light emitting unit, the output light is separated into the measurement light and the reference light by the light combining unit, and the measurement light is applied to the object to be measured on the table 22. To do. Then, the reflected light reflected by the object to be measured and the reference light are combined by the light combining section and received by the light receiving section. In such an optical probe 23, interference light is formed by the measurement light and the reference light, and by observing the interference fringes of the interference light at the light receiving portion, the surface texture of the measured object can be measured. ..

The moving mechanism 24 moves the optical probe 23 to, for example, an x-axis or a y-axis (y-axis is orthogonal to the x-axis) parallel to the measurement target placement surface 22A of the table 22, and is orthogonal to the measurement target placement surface 22A. Move along the z-axis. The moving mechanism 24 has scales for detecting the spatial position coordinates of the optical probe 23, and the detected coordinate position for each axis is output to the control unit 25. The x-axis, y-axis, and z-axis described here are different from the X-axis, Y-axis, and Z-axis described in the step height gauge 1 and are coordinate systems in the interferometer 2.
Further, the moving mechanism 24 has a drive mechanism (not shown) composed of a motor or the like, and the drive of the drive mechanism is controlled by the control unit 25, whereby the position of the optical probe 23 can be automatically controlled. ..

The control unit 25 includes, for example, an arithmetic circuit such as a CPU (Central Processing Unit) and a storage unit (a storage circuit or a storage drive) such as a memory. The storage means stores a reference plane measuring program for implementing the reference plane measuring method of the present invention, various programs for measuring an object to be measured and calibrating the reference plane, and various data. Then, the control unit 25 reads out and executes these various programs by the arithmetic circuit, and as illustrated in FIG. 4, the reference setting unit 251, the reference measurement point acquisition unit 252, the reference calculation unit 253, and the block measurement point acquisition unit. 254, and the height calculator 255 and the like.

The reference setting unit 251 sets the first reference measurement point in the first reference measurement area 112B and the second reference measurement point in the second reference measurement area 112C in the step height gauge 1 as described above.
In the present invention, the first reference measurement point and the second reference measurement point may be manually set appropriately by a measurer, but the position of the step height gauge 1 or any position of the block measurement surface 122 is set as a measurement target. If it is known, it is possible to set the first reference measurement point and the second reference measurement point that can measure the height dimension of each block measurement surface 122 with higher accuracy.
In this case, the reference setting unit 251 uses, for example, the optical probe 23, the position of the step height gauge 1 placed on the table 22, that is, the block measurement surface 122 of each gauge block 12, the first reference measurement area 112B, and the first reference measurement area 112B. The position of the second reference measurement area 112C is detected. Then, the reference setting unit 251 acquires the measurement position on the block measurement surface 122, which is set and input by the operation of the operation unit of the measurer, and the first reference measurement point in the first reference measurement region 112B that sandwiches the measurement position. , And the position coordinates of the second reference measurement point in the second reference measurement area 112C on the xy plane.

Here, the measurement position on the block measurement surface 122 is the acquisition position (block measurement point) of the height dimension when performing the calibration process using the step height gauge 1, and for example, the center of gravity position of the block measurement surface 122. Alternatively, the four corner positions on the block measurement surface 122 may be mentioned. The block measurement position acquired here is a position when the block measurement point is projected onto the xy plane, and the z-axis coordinate (height dimension) does not need to be acquired.

The reference measurement point acquisition unit 252 acquires the position coordinates (xyz position coordinates) of the first reference measurement point and the second reference measurement point. In the present embodiment, the Z coordinate axis measurement process using the optical probe 23 is performed on the xy coordinate positions of the first reference measurement point and the second reference measurement point set by the reference setting unit 251, and the z coordinate value is calculated. obtain.

The reference calculation unit 253 uses the position coordinates (xyz position coordinates) of the first reference measurement point and the second reference measurement point acquired by the reference measurement point acquisition unit 252 to determine the first reference measurement point and the second reference measurement point. Calculate the straight line (reference straight line) that passes through.
The block measurement point acquisition unit 254 acquires the position coordinates (xyz position coordinates) of the block measurement points on the block measurement surface 122.
The height calculator 255 calculates the distance (height dimension) from the reference straight line to the block measurement point from the reference straight line and the position coordinates of the measured block measurement point.

[Reference plane measurement method]
Next, a reference plane measuring method in the above-mentioned interference measuring apparatus 2 will be described.
FIG. 5 is a flowchart showing the reference plane measuring method. FIG. 6 is a schematic plan view for explaining a measuring method (reference plane measuring method) of each gauge block 12 of the step height gauge 1 in the present embodiment, and FIG. 7 is a schematic plan view.
In the reference surface measuring method according to the present embodiment, first, the reference setting unit 251 detects the mounting position of the step height gauge 1 on the table 22 (step S1; gauge detection step). In the present embodiment, the light receiving unit of the optical probe 23 has an image pickup device for observing interference fringes, so that the image pickup device acquires a picked-up image of the table 22 and detects the position of the step height gauge 1 from the picked-up image. It becomes possible to do.

Next, the reference setting unit 251 sets the first reference measurement point R1 and the second reference measurement point R2 of the step height gauge 1. For example, based on the block measurement point B (B1, B2, B3, B4, B5) input by the operation of the operation unit of the measurer (block measurement coordinate acquisition step), the first reference measurement point R1 and The coordinates on the XY plane of the first reference measurement point R1 and the second reference measurement point R2 are set so that the XY plane position of the block measurement point is located on the straight line passing through the second reference measurement point R2 (step S2: reference measurement point setting step).

For example, when an input operation is performed on the block measurement surface 122 of each gauge block 12 so that the center of gravity is set as the block measurement point B, the reference setting unit 251 causes the gauge setting block 251 to detect each gauge block. The barycentric position (xy coordinate position) is detected from the 12 positions, and a temporary reference straight line passing through these barycentric positions is calculated. That is, the reference setting unit 251 calculates a provisional reference straight line that passes through each position coordinate when each block measurement point B is projected on the xy plane. The xy plane is a plane parallel to the upper surface of the table 22 (measurement target mounting surface 22A), and the bottom surface 111 of the base 11 of the step height gauge 1 is placed in contact with the measurement target mounting surface 22A. Therefore, it becomes a surface (XY plane) parallel to the mounting surface 112 of the base 11.
Then, the reference setting unit 251 sets a point on the provisional reference line and within the first reference measurement region 112B as a first reference measurement point R1, and on the provisional reference line and within the second reference measurement region 112C. The point is set as the second reference measurement point R2. The position of the first reference measurement point R1 in the first reference measurement region 112B may be, for example, a preset position in the x direction (alignment direction of the gauge blocks 12) in the first reference measurement region 112B. Of course, the measurer may arbitrarily set it. When setting a preset position, for example, when the intersection of the boundary between the placement area 112A and the first reference measurement area 112B and the tentative reference line is the first reference measurement point R1, the first reference measurement described below is performed. When measuring the position coordinates of the point R1, the corner portion where the gauge block 12 rises from the mounting surface 112 is measured. Therefore, it is preferable to set the position on the provisional reference straight line in the first reference measurement region 112B, which is apart from the placement region 112A by a predetermined dimension, as the first reference measurement point R1. In the present embodiment, for example, as shown in FIGS. 6 and 7, the center position of the width dimension along the X direction of the first reference measurement region 112B is set as the first reference measurement point R1. The same applies to the position of the second reference measurement point R2 in the second reference measurement area 112C.
Further, in the present embodiment, an example in which the measurer operates the operation unit to specify the block measurement point B is shown. However, the present invention is not limited to this, and for example, a default value of the block measurement point B is set in advance. May be. For example, when there is no input from the operation unit, the barycentric position on the block measurement surface 122 may be set as the block measurement point B, and the xy position coordinates of the first reference measurement point R1 and the second reference measurement point R2 may be set.

Next, the reference measurement point acquisition unit 252 acquires the position coordinates by measuring the first reference measurement point R1 and the second reference measurement point R2 obtained in step S2 (step S3; reference measurement point acquisition step). ..
That is, the first reference measurement point R1 and the second reference measurement point R2 obtained in step S2 are two-dimensional coordinates on the xy plane (mounting surface 112), and the height dimension (z-axis coordinate) is Unknown. In step S3, the reference measurement point acquisition unit 252 controls the optical probe 23 and the moving mechanism 24 to perform measurement on the first reference measurement point R1 and the second reference measurement point R2, and acquire accurate xyz position coordinates. To do.

After step S3, the reference calculation unit 253 calculates the reference straight line P (see FIGS. 6 and 7) passing through the first reference measurement point R1 and the second reference measurement point R2 calculated in step S3 (step S4; Reference calculation step). The reference straight line P cancels (averages) the surface accuracy of the mounting surface 112 between the first reference measurement point R1 and the second reference measurement point R2, the surface accuracy of each block measurement surface 122, and the ringing defect with each gauge block 12. It becomes a straight line.

After that, the block measurement point acquisition unit 254 performs measurement on the block measurement points B (B1, B2, B3, B4, B5) of each gauge block 12 and acquires the position coordinates (step S5; block measurement point acquisition). Step).
The height calculation unit 255 then calculates the distance (L1, L2, L3, L4, L5) between the position coordinates of each block measurement point B acquired (measured) in step S5 and the reference straight line P calculated in step S5. ) Is calculated as the height dimension of each block measurement surface 122 (step S6; reference height calculation step).
As described above, the height dimension (reference height dimension) of the block measurement surface 122 of each gauge block 12 in the step height gauge 1 is calculated.

[Operation and effect of this embodiment]
The step height gauge 1 of the present embodiment includes a base 11 having a smooth mounting surface 112, and a plurality of gauge blocks 12 ringing on the mounting surface 112. The gauge block 12 includes a ringing surface 121 that is ringed on the mounting surface 112, and a block measurement surface 122 that is opposite to the ringing surface 121 and that is parallel to the ringing surface 121. The mounting surface 112 of the base 11 has a mounting area 112A on which the plurality of gauge blocks 12 are mounted side by side in the X direction, and an outside of the mounting area 112A (- The first reference measurement area 112B provided on the X side) and the second reference measurement area 112C provided on the outer side (+X side) of the placement area 112A, and the first reference measurement area 112B and the second reference measurement area 112B. The reference measurement area 112C is exposed to the outside.

In the step height gauge 1 having such a configuration, by performing the reference measurement point acquisition step, the reference calculation step, the block measurement point acquisition step, and the reference height calculation step, the height of each block measurement surface 122 can be accurately adjusted. The size can be calculated.
That is, in the reference measurement point acquisition step, the respective position coordinates of the first reference measurement point R1 in the first reference measurement area 112B and the second reference measurement point R2 in the second reference measurement area 112C are measured. Then, in the reference calculation step, a reference straight line P connecting these first reference measurement point R1 and second reference measurement point R2 is calculated. In the block measurement point acquisition step, the position coordinates of each block measurement point B are measured. Then, in the reference height calculation step, the distance (height dimension) from the reference straight line P to each block measurement point B is calculated.
In the reference calculation step, the reference straight line P is calculated from the position coordinates of the first reference measurement point R1 and the second reference measurement point R2, which are provided at the positions sandwiching the plurality of gauge blocks 12, and thus the mounting surface 112 is obtained. Even if a portion of the block measurement surface 122 with low surface accuracy exists, or if the block measurement surface 122 is slightly inclined due to ringing failure or the like, the errors due to these inconveniences are averaged. It can be canceled, and the height dimension up to each block measurement surface 122 can be obtained with high accuracy.

The step height gauge 1 of the present embodiment includes a cover 13 that covers the side surface portion 113 of the base 11. The cover 13 is adhesively fixed to the side surface portion 113 of the base 11 and the side surface of the gauge block 12, and in a plan view seen from the normal line of the mounting surface 112, the mounting area 112A, the first reference measurement area 112B, And an opening 131 in a portion corresponding to the second reference measurement area 112C.
If the cover 13 covers the entire area other than the mounting area 112A in a plan view of the mounting surface 112 viewed from the normal, the position coordinates of the first reference measurement point R1 and the second reference measurement point R2 are measured. I can't. On the other hand, in the present embodiment, since the cover 13 is provided with the opening 131 that exposes the first reference measurement region 112B and the second reference measurement region 112C to the outside, the reference surface measurement process as described above is performed. Is possible.
Further, by providing such a cover 13, the step height gauge 1 can be protected. Further, since the cover 13 is adhesively fixed to the base 11 and the gauge block 12 in a state where the base 11 and the gauge block 12 are ringed, the positional deviation between the base 11 and the gauge block 12 can be suppressed, and the gauge block can be suppressed. The ring 12 can be kept ringing on the base 11.

Further, the cover 13 covers a side surface portion 113 from the bottom surface 111 of the base 11 to a mounting surface 112 from a position having a predetermined dimension. That is, the bottom surface 111 of the base 11 is exposed. Therefore, when mounting the step height gauge 1 on the table 22, the bottom surface 111 and the table 22 can be brought into contact with each other, and the measurement target mounting surface 22A, the bottom surface 111, the mounting surface 112, and each gauge block. The twelve block measuring surfaces 122 can be kept parallel.

The interference measuring apparatus 2 of the present embodiment includes a table 22 on which the step height gauge 1 as described above is placed, a first reference measurement point R1, a second reference measurement point R2, and each block in the step height gauge 1. An optical probe 23 capable of measuring the position coordinates of the measurement point B is provided. Then, the control unit 25 of the interference measuring apparatus 2 includes a reference measurement point acquisition unit 252 that acquires the position coordinates of the first reference measurement point R1 and the second reference measurement point R2 of the step height gauge 1, and these first reference points. A reference calculation unit 253 that calculates the reference straight line P from the measurement point R1 and the second reference measurement point R2, a block measurement point acquisition unit 254 that acquires the block measurement point B, and a reference straight line P and each block that has been acquired (measured). It functions as a height calculator 255 that calculates the distance (height dimension) from the measurement point B.
Therefore, as described above, the reference measurement point acquisition step, the reference calculation step, the block measurement point acquisition step, and the reference height calculation step can be performed, and the block measurement of each gauge block 12 of the step height gauge 1 can be performed. The height dimension of the surface 122 can be obtained with high accuracy.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, but also includes the following modifications within a range in which the object of the present invention can be achieved.

FIG. 8 is a perspective view showing another configuration example of the step height gauge according to the present invention.
In the above-described embodiment, an example is shown in which five gauge blocks 12 having different heights are arranged side by side along the X direction without a gap with respect to the base 11, but the present invention is not limited to this.
For example, as in the step height gauge 1A shown in FIG. 8A, for example, a gap may be provided between the adjacent gauge blocks 12.
Further, in the above embodiment, an example in which the gauge blocks 12 are arranged side by side so that the height dimension of the gauge block 12 gradually increases in the X direction has been shown, but the present invention is not limited to this. For example, as in the step height gauge 1B shown in FIG. 8B, the height dimension of the gauge block 12 may be increased or decreased along the X direction.
Furthermore, although an example in which five gauge blocks 12 are provided has been shown, two or more gauge blocks 12 may be provided, and for example, a step height gauge in which three gauge blocks 12 are provided may be used.

Furthermore, in the above-described embodiment, an example in which each gauge block 12 is manufactured as a separate body and then ringed on the base 11 is shown, but a plurality of gauge blocks 12 may be integrally configured. .. That is, one block body in which a plurality of gauge blocks 12 are integrated may be provided, and the block body may be ringed to the base 11. Even in this case, similarly to the above-described embodiment, the reference straight line P is calculated by measuring the first reference measurement point R1 and the second reference measurement point R2 arranged with the block body interposed therebetween, and the block is calculated from the reference straight line P. The distance to each step surface (upper surface) of the body may be calculated as the height dimension, and the same effect as the above embodiment can be obtained.
Alternatively, the base 11 and the gauge block 12 may be integrally configured. Also in this case, after calculating the reference straight line P based on the first reference measurement point R1 and the second reference measurement point R2 of the base 11, the height dimension between the reference straight line P and each block measurement point B is calculated. Therefore, for example, the measurement can be performed with higher accuracy as compared with the case where the block measuring surface 122 of one gauge block 12 is used as a reference surface to measure the height dimension of another block measuring surface.

Furthermore, although an example in which a plurality of gauge blocks 12 are provided side by side along the X direction has been shown, as in the step height gauge 1C shown in FIG. 8C, Y intersecting with the X direction (for example, orthogonal). The gauge block 12 may also be arranged in the direction.
In this case, the third reference measurement region 112D and the fourth reference measurement region capable of measuring reference measurement points for calculating the reference straight line along the Y direction are provided on both sides of the gauge block 12 arranged along the Y direction. 112E may be provided.

In the above embodiment, the reference calculation unit 253 shows an example in which the reference straight line P including the first reference measurement point R1 and the second reference measurement point R2 is calculated, but the present invention is not limited to this. For example, the reference calculator 253 may calculate the reference plane from the position coordinates of the first reference measurement point R1, the second reference measurement point R2, and another reference measurement point that is not on the reference straight line P. In this case, in step S2, it is not necessary to set the first reference measurement point R1 and the second reference measurement point R2 based on the provisional reference straight line that passes through the position coordinates when the block measurement point B is projected on the XY plane. .. That is, the distance between the calculated reference plane and the measured block measurement point may be calculated regardless of the position of the block measurement point.
In particular, as shown in FIG. 8C, even when the gauge block 12 is arranged not only in the X direction but also in another direction (for example, the Y direction), the reference height dimension based on the reference plane is It becomes possible to measure.

In the above-described embodiment, the non-contact type optical probe 23 is exemplified as the measuring mechanism for measuring the object to be measured, but the measuring mechanism is not limited to this. As the non-contact type probe, in addition to the optical probe 23 as described above for observing interference fringes, the shape of the object to be measured is measured by triangulation based on a captured image when the object to be measured is irradiated with line light. An image probe or the like may be used. Further, the probe is not limited to the non-contact type probe, and a contact type probe that measures the surface texture of the measured object by bringing the touch probe into contact with the measured object and reading the contact position with a sensor such as a scale may be used. Good.

In the above embodiment, the control unit 25 controls the drive mechanism of the moving mechanism 24 to automatically control the position of the optical probe 23. However, the present invention is not limited to this. For example, the measurer may manually move the optical probe 23.

In the above-described embodiment, the position of the step height gauge 1 is detected based on the captured image on the table 22 in step S1, but the present invention is not limited to this. For example, when a contact-type touch probe or the like is used as a measurement unit for measuring an object to be measured, preliminary measurement is performed on the step height gauge 1, and the gauge block 12, the first reference measurement area 112B, and the second reference measurement area are used. The position of the measurement area 112C may be detected.

In the above embodiment, the configuration in which the step height gauge 1 is provided with the cover 13 has been illustrated, but the configuration of the cover 13 is not essential, and for example, the configuration in which the cover 13 is not provided may be adopted. Although the cover 13 covers the mounting surface 112 from a height position of a predetermined dimension above the bottom surface 111, the cover 13 may cover the mounting surface 112 from the same height position as the bottom surface 111 of the side surface portion 113. .. If the cover 13 can be flattened with high precision, the bottom surface 111 may be covered with the cover 13.

In addition, the specific structure and procedure for carrying out the present invention can be appropriately changed to other structures and the like within the range in which the object of the present invention can be achieved.

The present invention provides a step height gauge for calibrating a reference surface (reference height surface), and various measuring devices for calibrating the reference surface using the step height gauge to perform measurement on an object to be measured, It can be used as a gauge measuring device for evaluating a reference gauge such as a step height gauge.

DESCRIPTION OF SYMBOLS 1... Step height gauge, 2... Interference measuring device (reference surface measuring device), 11... Base, 12... Gauge block, 13... Cover, 22... Table, 22A... Measuring object mounting surface, 23... Optical probe, 24 ... Moving mechanism, 25... Control part, 111... Bottom surface, 112... Mounting surface, 112A... Mounting area, 112B... First reference measurement area, 112C... Second reference measurement area, 112D... Third reference measurement area, 112E ... fourth reference measurement area, 113... side surface portion, 121... ringing surface (lower surface of gauge block), 122... block measurement surface (upper surface of gauge block), 131... opening, 251... reference setting portion, 252... reference measurement point Acquisition unit, 253... Reference calculation unit, 254... Block measurement point acquisition unit, 255... Height calculation unit, B... Block measurement point, P... Reference straight line, R1... First reference measurement point, R2... Second reference measurement point ..

Claims (5)

A base having a smooth mounting surface,
With a plurality of gauge blocks placed on the placement surface ,
A cover that covers a side surface portion that intersects the mounting surface of the base, and a cover that is adhesively fixed to the base and the gauge block ,
The gauge block includes a lower surface that is ringed to the mounting surface, and a surface opposite to the lower surface and an upper surface parallel to the lower surface.
The placement surface is, in a plan view seen from the normal direction, a placement region where the plurality of gauge blocks are placed side by side in one direction, and on the outside of the placement region on one side of the one direction. a first reference measurement area exposed provided outside, possess a second reference measurement area exposed is provided on the outside of the front according depositing area outside the the other side of said one direction,
The step height gauge , wherein the cover has openings corresponding to the first reference measurement area, the second reference measurement area, and the placement area . The step height gauge according to claim 1,
The cover, from the position of the side surface portion closer to the mounting surface by a predetermined dimension than the bottom surface of the base opposite to the mounting surface, the mounting area of the mounting surface, the first reference measurement A step height gauge, which covers an area and an area other than the second reference measurement area . A reference plane measuring method for measuring the height of a reference plane using the step height gauge according to claim 1 or 2 .
The first reference measurement point provided on the outside of the placement area on one side of the placement area in which the gauge block of the placement surface is placed, the other of the one direction of the placement area A reference measurement point acquisition step of acquiring the position coordinates of the second reference measurement point provided outside the placement area on the side,
A block measurement point acquisition step of acquiring the position coordinates of the block measurement point on the upper surface of the gauge block,
From the positions of the first reference measurement point and the second reference measurement point, a reference calculation step of calculating a reference straight line including the first reference measurement point and the second reference measurement point,
From the reference straight line, a reference height calculation step of calculating a dimension from the block measurement point,
A method for measuring a reference plane, which comprises: The reference plane measuring method according to claim 3,
The block measurement coordinate acquisition step of acquiring the measurement coordinates of the block measurement point relative to the planar view from the normal direction of the mounting surface,
The reference measurement point acquisition step, the position coordinates of the block measurement point relative to the plane view from the normal direction of the mounting surface, the first reference measurement point and the first reference point is included on the reference straight line in the plan view. (Ii) A reference plane measuring method characterized by obtaining the position coordinates of a reference measurement point. A reference plane measuring device for measuring the height of a reference plane using the step height gauge according to claim 1 or 2 .
The first reference measurement point provided on the outside of the placement area on one side of the placement area in which the gauge block of the placement surface is placed, the other of the one direction of the placement area A reference measurement point acquisition unit that acquires the position coordinates of the second reference measurement point provided outside the placement area on the side,
A block measurement point acquisition unit for acquiring the position coordinates of the block measurement points on the upper surface of the gauge block,
From the position coordinates of the first reference measurement point and the second reference measurement point, a reference calculation unit that calculates a reference straight line including the first reference measurement point and the second reference measurement point,
From the reference straight line, a height calculation unit that calculates the dimension from the block measurement point,
A reference plane measuring device comprising:

Images