JP2009192296A - Shape measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shape measuring apparatus which includes a simple mechanism but can precisely carry out a high-reliability shape measurement. <P>SOLUTION: A deviation value of a sphere 200 from a reference position in an optical axis direction is measured by a position measuring means (CPU 81, position measuring program 83b4), and magnified scale factor information based on the deviation value is extracted from a compensation value memory means (compensation value data table 83a) by a magnified scale factor information extracting means (CPU 81, magnified scale factor information extracting program 83b5), based on the deviation value of the sphere 200 from the reference position in the optical axis direction measured by the position measuring means, and then one cross-section shape which is calculated by a cross-section shape calculating means (CPU 81, cross-section shape calculating program 83b1), is compensated by a cross-section shape compensating means (CPU 81, cross-section shape compensating program 83b6), based on the magnified scale factor information extracted by the magnified scale factor information extracting means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shape measuring apparatus.

In recent years, microfabrication technology has advanced. For example, when a small sphere (diameter of 1 to 2 mm or less) is machined, a measuring element having a fine tip sphere is used to measure the sphericity of the small sphere. Therefore, a probe (measuring element) processing method and a processing machine for processing such a measuring element have been considered (see Patent Document 1).
However, even if a probe having such a fine tip sphere can be processed, it cannot be performed until the sphericity of the fine tip sphere of the processed probe is measured. Sphericality measurement has been the key to improving the precision of minute probing systems that are expected to develop in the future.
Then, as a method for measuring the sphericity of such a fine tip sphere, for example, as shown in FIG. 9, the subject to be measured is rotated about a stem attached to the subject to be measured (tip sphere) as a rotation axis, and sequentially. A method of measuring the sphericity based on a shape obtained by measuring a cross-sectional shape of an object to be measured and combining a plurality of measured cross-sectional shapes is considered.
However, in this method, as shown in FIG. 10, the rotation error and eccentricity of the stem used as the rotating shaft are major error factors for the shape measurement. In particular, since it is necessary to use a high-magnification optical system in order to measure a minute object to be measured, the depth of field becomes shallow. For this reason, even an eccentricity of several μm causes a large error.
Therefore, as means for removing such an error, a technique using a telecentric lens in an optical system and various autofocus techniques are used.
JP 2005-96033 A

  However, even when using a telecentric lens with good telecentricity (parallelism of the principal ray with respect to the optical axis), there are many cases where errors cannot be ignored when determining object dimensions by sub-pixel processing, etc. Even when the autofocus technique is used, the accuracy of autofocus is poor, and an accurate cross-sectional shape cannot be obtained. Therefore, there is a problem that shape measurement with high accuracy and high reliability cannot be performed.

  An object of the present invention is to provide a shape measuring apparatus capable of performing shape measurement with higher accuracy.

In order to solve the above problems, the invention described in claim 1
In a shape measuring apparatus that measures the cross-sectional shape of a measurement object that is a rotationally symmetric body and measures the shape of the measurement object,
Holding means for holding the object to be measured at a predetermined reference position;
A light source unit for irradiating the object to be measured held by the holding unit with light;
An imaging unit that captures a map formed by irradiating the object to be measured held by the holding unit with the light output from the light source unit;
A cross-sectional shape calculating means for calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
Rotating means for rotating the object to be measured at a predetermined angle around the rotational symmetry axis of the object to be measured;
Each time the object to be measured is rotated at a predetermined angle by the rotating means, a cross-sectional shape of the object to be measured is calculated by the cross-sectional shape calculating means, and the object to be measured is calculated based on the calculated plurality of cross-sectional shapes of the object to be measured. A shape measuring means for measuring the shape of the measuring object;
With
The cross-sectional shape calculating means
Correction amount storage means for storing magnification information corresponding to the amount of deviation in the optical axis direction from the reference position of the object to be measured;
Position measuring means for measuring a deviation amount of the object to be measured from the reference position in the optical axis direction;
Based on the amount of deviation of the measured object from the reference position in the optical axis direction measured by the position measuring means, the magnification information extracting means extracts the magnification information corresponding to the deviation amount from the correction amount storage means. When,
A cross-sectional shape correcting means for correcting one cross-sectional shape calculated by the cross-sectional shape calculating means based on the enlargement magnification information extracted by the enlargement magnification information extracting means;
It is characterized by providing.

The invention according to claim 2 is the shape measuring apparatus according to claim 1,
A moving mechanism for moving the object to be measured in an optical axis direction of light output from the light source unit;
The correction amount storage means includes
The cross-sectional shape calculating means calculates one cross-sectional shape of the measured object every time the moving mechanism moves the measured object from the reference position in the optical axis direction by the moving mechanism. Based on the amount of movement and the size of one cross-sectional shape of the measured object calculated by the cross-sectional shape calculating means, from the reference position of the measured object for correcting a focus shift when measuring the cross-sectional shape Magnification information corresponding to the amount of deviation in the optical axis direction is stored.

The invention according to claim 3
In a shape measuring apparatus that measures the cross-sectional shape of a measurement object that is a rotationally symmetric body and measures the shape of the measurement object,
Holding means for holding the object to be measured at a predetermined reference position;
A light source unit for irradiating the object to be measured held by the holding unit with light;
A moving mechanism for moving the object to be measured in an optical axis direction of light output from the light source unit;
An imaging unit that captures a map formed by irradiating the object to be measured held by the holding unit with the light output from the light source unit;
A cross-sectional shape calculating means for calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
Rotating means for rotating the object to be measured at a predetermined angle around the rotational symmetry axis of the object to be measured;
Each time the object to be measured is rotated at a predetermined angle by the rotating means, a cross-sectional shape of the object to be measured is calculated by the cross-sectional shape calculating means, and the object to be measured is calculated based on the calculated plurality of cross-sectional shapes of the object to be measured. A shape measuring means for measuring the shape of the measuring object;
With
The cross-sectional shape calculating means
It is characterized by comprising position measuring means for measuring the amount of deviation in the optical axis direction from the reference position of the measured object.

The invention according to claim 4 is the shape measuring apparatus according to any one of claims 1 to 3,
Second imaging means for imaging the object to be measured from a direction intersecting an optical axis direction of light output from the light source unit;
Second cross-sectional shape calculating means for calculating one cross-sectional shape of the object to be measured from the light intensity distribution of the map imaged by the second imaging means;
Center position calculating means for calculating a center position of the object to be measured based on the cross-sectional shape calculated by the second cross-sectional shape calculating means;
With
The position measuring means includes
Based on the center position of the object to be measured calculated by the center position calculating means, a deviation amount in the optical axis direction from the reference position of the object to be measured is measured.

The invention according to claim 5 is the shape measuring device according to any one of claims 1 to 4,
The object to be measured is a sphere.

According to the first aspect of the present invention, the holding means for holding the measured object at a predetermined reference position, the light source unit for irradiating the measured object held by the holding means, and the holding means An imaging unit that captures a map formed by irradiating the measured object with light output from the light source unit, and a cross-sectional shape that calculates a cross-sectional shape of the measured object from a light intensity distribution of the map captured by the imaging unit A calculating means, a rotating means for rotating the measured object around a rotational symmetry axis of the measured object at a predetermined angle, and a cross-sectional shape calculating means for measuring the measured object every time the measured object is rotated at a predetermined angle by the rotating means. And a shape measuring means for measuring the shape of the measured object based on the calculated plurality of cross-sectional shapes of the measured object. Measured object The magnification information corresponding to the amount of deviation in the optical axis direction from the reference position can be stored, and the amount of deviation in the optical axis direction from the reference position of the object to be measured is measured by the position measuring means provided in the cross-sectional shape calculating means. Based on the deviation in the optical axis direction from the reference position of the measured object measured by the position measuring means by the magnification information extracting means provided in the cross-sectional shape calculating means, the deviation can be measured from the correction amount storage means. The magnification information corresponding to the amount can be extracted, and is calculated by the cross-sectional shape calculating unit based on the magnification information extracted by the magnification information extracting unit by the cross-sectional shape correcting unit included in the cross-sectional shape calculating unit. The cross-sectional shape can be corrected.
Therefore, when the object to be measured is rotated around the rotational symmetry axis of the object to be measured by the rotating means, the object to be measured is displaced from the reference position due to rotational error or eccentricity error, and is calculated by the cross-sectional shape calculating means. Even if an error occurs in the cross-sectional shape of the measured object, the cross-sectional shape can be corrected based on the amount of deviation in the optical axis direction from the reference position of the measured object. Measurements can be made.

According to the second aspect of the present invention, it is needless to say that the same effect as that of the first aspect of the invention can be obtained, and that the object to be measured is moved in the direction of the optical axis of the light output from the light source unit. Each time a predetermined amount of movement of the object to be measured is moved from the reference position to the optical axis direction by the movement mechanism by the correction amount storage means, and the cross-sectional shape calculating means calculates one cross-sectional shape of the object to be measured, The reference position of the measured object for correcting the focus shift when measuring the cross-sectional shape based on the movement amount of the measured object and the size of the cross-sectional shape of the measured object calculated by the cross-sectional shape calculating means Magnification information corresponding to the amount of deviation in the optical axis direction can be stored.
Therefore, it is possible to store magnification information corresponding to the amount of deviation in the optical axis direction from the reference position of the object to be measured for correcting the focus deviation based on the object to be actually measured for shape measurement. As a result, it is possible to perform shape measurement with higher accuracy.

According to the third aspect of the present invention, the holding means for holding the measured object at a predetermined reference position, the light source unit for irradiating the measured object held by the holding means, and the output from the light source unit A moving mechanism for moving the object to be measured in the optical axis direction of the light to be measured, an image pickup means for picking up an image formed by irradiating the light to be measured held by the holding means with light output from the light source unit, and an image pickup means A cross-sectional shape calculating means for calculating a cross-sectional shape of the object to be measured from the light intensity distribution of the map imaged by the rotation means, a rotating means for rotating the object to be measured at a predetermined angle around the rotational symmetry axis of the object to be measured, and rotation. Each time the measured object is rotated by a predetermined angle, the cross-sectional shape calculating means calculates one cross-sectional shape of the measured object, and the shape of the measured object is measured from the calculated cross-sectional shapes of the measured object. Shape measuring means The provided by the position measuring means provided in the cross-sectional shape calculation unit, it is possible to measure the amount of deviation of the optical axis direction from the reference position of the object to be measured.
Therefore, when the object to be measured is rotated about the rotational symmetry axis of the object to be measured by the rotating means, even if the object to be measured is displaced from the reference position due to an error in rotational motion or an error in eccentricity, The measuring unit measures the amount of deviation of the object to be measured from the reference position in the optical axis direction, and based on the measured amount of deviation, the moving object causes the object to be measured to match the reference position. Therefore, it is possible to perform shape measurement with higher accuracy.

According to the invention described in claim 4, it is needless to say that the same effect as that of any one of claims 1 to 3 can be obtained, and is output from the light source unit by the second imaging means. The object to be measured can be imaged from a direction intersecting the optical axis direction of the light, and one cross section of the object to be measured is calculated from the light intensity distribution of the map imaged by the second imaging means by the second cross sectional shape calculating means. The shape can be calculated, the center position calculating means can calculate the center position of the measured object based on the cross-sectional shape calculated by the second cross-sectional shape calculating means, and the position measuring means can calculate the center position. Based on the center position of the measured object calculated by the means, the amount of deviation of the measured object from the reference position in the optical axis direction can be measured.
Accordingly, when the object to be measured is rotated about the rotational symmetry axis of the object to be measured by the rotating means, even if the object to be measured is displaced from the reference position due to an error in rotational motion or an error in eccentricity, The amount of deviation in the optical axis direction from the reference position of the object to be measured can be measured from the direction intersecting the optical axis direction of the light output from the unit, and the object to be measured is rotated based on the amount of deviation. An error in rotational motion and an error in eccentricity can be suitably corrected.

  According to the invention described in claim 5, it is needless to say that the same effect as that of the invention described in any one of claims 1 to 4 can be obtained, and more accurate shape measurement is performed for a sphere. be able to.

  Hereinafter, specific embodiments of the shape measuring apparatus according to the present invention will be described with reference to the drawings. In the present embodiment, a spherical object will be described as an example of the object to be measured.

<First Embodiment>
As shown in FIG. 1, the shape measuring apparatus 100 according to the first embodiment includes a light source unit 10, a moving mechanism 20 that moves a sphere (object to be measured) 200, a rotary table 30 that rotates and supports the sphere 200, and a sphere The first objective lens 40 for imaging the 200 on the first imaging unit 50, the first imaging unit 50 for imaging the sphere 200, and the second objective lens for imaging the sphere 200 on the second imaging unit 70 60, a second imaging unit 70 that images the sphere 200, and an image processing unit 80. The sphere 200, the first objective lens 40, and the like in order along the optical axis of the light emitted from the light source unit 10. , The first imaging unit 50, the second objective lens 60, and the second imaging unit above the sphere 200 arranged in a direction intersecting the optical axis direction and on the optical axis. 70 are arranged.

  For example, as illustrated in FIG. 1, the light source unit 10 irradiates the sphere 200 with white light using a point light source that outputs white light. The light source unit 10 is not limited to such a point light source, and may be a surface light source, or may generate light using a discharge lamp, a light emitting diode, a laser, or the like.

For example, as shown in FIG. 1, the moving mechanism 20 includes a base 21 and a slider 22 installed on the upper surface of the base 21, and a driving force by a driving source (not shown) is controlled by the CPU 81. The slider 22 can be moved along the direction of the optical axis (z-axis) of the light from the light source unit 10, and the position can be adjusted to a predetermined reference position.
Here, the “predetermined reference position” refers to a mechanical origin in the moving mechanism 20, an electrical origin in the case of having an origin offset function, and the like.
Further, the moving mechanism 20 is configured to be able to place the rotary table 30 that can hold the sphere 200, and the moving mechanism 20 functions as a holding unit that holds the sphere 200 at a predetermined reference position. .

For example, as shown in FIG. 1, the rotary table 30 is disposed on the upper surface of the slider 22, and is disposed so as to be rotatable about an axis (y axis) perpendicular to the upper surface of the slider 22.
Specifically, the rotary table 30 includes a gripping portion (not shown) such as a collet chuck. When the shaft portion 201 integrally formed with the sphere 200 is gripped by the gripping portion, the shaft portion 201 is a light source. It arrange | positions so that it may become a right angle with respect to the optical axis of the part 10, and can rotate the spherical body 200 by making the axial part 201 into a rotating shaft, Thereby, the turntable 30 functions as a rotation means.
Further, the turntable 30 includes an encoder (not shown) and can control the rotation angle.

  For example, as illustrated in FIG. 1, the first objective lens 40 is disposed between the sphere 200 and the imaging surface of the first imaging unit 50 on the optical axis of the light emitted from the light source unit 10. This is used to form an image of the sphere 200 on the imaging surface of the first imaging unit 50.

For example, a CCD camera is used as the first imaging unit 50 and images a mapping through the first objective lens 40.
Specifically, as shown in FIG. 1, a mapping formed by the light output from the light source unit 10 irradiating the sphere 200 is imaged through the first objective lens 40.
The first imaging unit 50 functions as an imaging unit by imaging a mapping using such a CCD camera.

For example, as shown in FIG. 1, the second objective lens 60 is disposed in a direction intersecting the optical axis of the light emitted from the light source unit 10 and above the sphere 200 disposed on the optical axis. ing.
Specifically, the second objective lens 60 is disposed between the sphere 200 and the imaging surface of the second imaging unit 70 in a direction intersecting the optical axis of the light emitted from the light source unit 10. The image of the sphere 200 is used to form an image on the imaging surface of the second imaging unit 70.

For example, a CCD camera is used as the second imaging unit 70 and images a mapping through the second objective lens 60.
Specifically, as shown in FIG. 1, the second imaging unit 70 has a direction intersecting with the optical axis of the light emitted from the light source unit 10 and the optical axis, like the second objective lens 60. An image formed by irradiating the sphere 200 with light output from the light source unit 10 disposed above the sphere 200 disposed above is imaged through the second objective lens 60.
The second imaging unit 70 functions as a second imaging unit by imaging a mapping using such a CCD camera.

  As shown in FIG. 1, for example, the image processing unit 80 includes a CPU (Central Processing Unit) 81, a RAM (Random Access Memory) 82, a storage unit 83, a display unit 84 that displays an image processing result, and the like. When a predetermined program stored in the storage unit 83 is executed, it has a function of performing operation control of each unit based on predetermined operation conditions set in advance in order to perform a predetermined operation.

  For example, the CPU 81 reads out a processing program or the like stored in the storage unit 83, develops it in the RAM 82, and executes it, thereby performing image processing or the like of the sphere 200.

  The RAM 82 expands the processing program executed by the CPU 81 in the program storage area in the RAM 82, and stores the input data and the processing result generated when the processing program is executed in the data storage area.

  The storage unit 83 has, for example, a storage medium (not shown) in which programs, data, and the like are stored in advance, and this storage medium is configured by, for example, a semiconductor memory. The storage unit 83 stores various data for the CPU 81 to perform image processing, various processing programs, data processed by executing these programs, and the like. More specifically, for example, as shown in FIG. 1, the storage unit 83 stores a correction amount data table 83a, a cross-sectional shape calculation program 83b1, a second cross-sectional shape calculation program 83b2, a center position calculation program 83b3, and a position measurement program 83b4. , An enlargement magnification information extraction program 83b5, a cross-sectional shape correction program 83b6, a shape measurement program 83b7, and the like.

The correction amount data table 83a is a table storing magnification information corresponding to the amount of deviation of the sphere 200 from the predetermined reference position in the optical axis direction.
Specifically, for example, as shown in FIG. 2, the correction amount data table 83a is obtained by executing the cross-sectional shape calculation program 83b1 by the CPU 81 when the sphere 200 that performs shape measurement is set at a predetermined reference position. 200, and then the CPU 81 executes the cross-sectional shape calculation program 83b1 each time the sphere 200 is moved from the reference position by the moving mechanism 20 in the optical axis direction, for example, ± 5 μm. It is a table in which one cross-sectional shape is calculated, and magnification information of one cross-sectional shape of the sphere 200 corresponding to the amount of deviation of the sphere 200 from the reference position in the optical axis direction at this time is stored.
More specifically, for example, as shown in FIG. 3, the amount of change in diameter as the magnification information of one cross-sectional shape of the sphere 200 corresponding to the amount of deviation of the sphere 200 from the predetermined reference position in the optical axis direction. Remember.
Thus, the correction amount data table 83a functions as a correction amount storage unit.

The cross-sectional shape calculation program 83b1 is a program that causes the CPU 81 to realize a function of calculating one cross-sectional shape of the sphere 200.
Specifically, for example, the CPU 81 calculates one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the first imaging unit 50 by executing the cross-sectional shape calculation program 83b1.
The CPU 81 functions as a cross-sectional shape calculating unit by executing the cross-sectional shape calculating program 83b1.

The second cross-sectional shape calculation program 83b2 is a program that causes the CPU 81 to realize a function of calculating one cross-sectional shape of the sphere 200.
Specifically, for example, the CPU 81 calculates one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the second imaging unit 70 by executing the second cross-sectional shape calculation program 83b2.
The CPU 81 functions as a second cross-sectional shape calculating unit by executing the second cross-sectional shape calculating program 83b2.

The center position calculation program 83b3 is a program that causes the CPU 81 to realize a function of calculating the center position of the sphere 200.
Specifically, for example, the CPU 81 executes the center position calculation program 83b3 to calculate the center position of the sphere 200 based on the one cross-sectional shape calculated by the execution of the second cross-sectional shape calculation program 83b2.
The CPU 81 functions as a center position calculation unit by executing the center position calculation program 83b3.

The position measurement program 83b4 is a program that causes the CPU 81 to realize a function of measuring the amount of deviation of the sphere 200 from the predetermined reference position in the optical axis direction.
Specifically, for example, the CPU 81 executes the position measurement program 83b4 to measure the amount of deviation in the optical axis direction from the predetermined reference position of the sphere 200 based on the center position of the sphere 200.
More specifically, for example, the CPU 81 calculates the one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the second imaging unit 70 by executing the second cross-sectional shape calculation program 83b2. Then, the CPU 81 executes the center position calculation program 83b3, thereby calculating the center position of the sphere 200 based on the one cross-sectional shape calculated by the execution of the second cross-sectional shape calculation program 83b2. The amount of deviation in the optical axis direction from the position is measured.
The CPU 81 functions as a position measurement unit by executing the position measurement program 83b4.

The enlargement magnification information extraction program 83b5 is a program that causes the CPU 81 to realize a function of extracting predetermined enlargement magnification information from the correction amount data table 83a.
Specifically, for example, the CPU 81 executes the magnification information extraction program 83b5 to correspond to the amount of deviation in the optical axis direction from the predetermined reference position of the sphere 200 measured by the execution of the position measurement program 83b4. The magnification information is extracted from the correction amount data table 83a.
More specifically, FIG. 3 will be described as an example. For example, the amount of deviation in the optical axis direction from the predetermined reference position of the sphere 200 measured by the CPU 81 executing the position measurement program 83b4 is −25 μm. In this case, the CPU 81 executes the enlargement magnification information extraction program 83b5 to extract the diameter change parameter value (0.5) as enlargement magnification information corresponding to the deviation amount minus 25 μm.
The CPU 81 functions as an enlargement ratio information extraction unit by executing the enlargement ratio information extraction program 83b5.

The cross-sectional shape correction program 83b6 is a program that causes the CPU 81 to realize a function of correcting one cross-sectional shape of the sphere 200.
Specifically, for example, the CPU 81 executes calculation of the cross-sectional shape calculation program 83b1 based on the enlargement magnification information extracted by executing the enlargement magnification information extraction program 83b5 by executing the cross-sectional shape correction program 83b6. Correct one cross-sectional shape.
More specifically, for example, as described above, when the CPU 81 executes the enlargement magnification information extraction program 83b5 to extract the diameter change parameter value as the enlargement magnification information, the CPU 81 executes the cross-sectional shape correction program 83b6. Thus, the diameter change parameter value extracted by the execution of the enlargement magnification information extraction program 83b5 is applied to a predetermined correction formula, and the value of the diameter in one cross-sectional shape of the sphere 200 calculated by the execution of the cross-sectional shape calculation program 83b1 is obtained. to correct.
The CPU 81 functions as a cross-sectional shape correcting unit by executing the cross-sectional shape correcting program 83b6.

The shape measurement program 83b7 is a program that causes the CPU 81 to realize a function of measuring the shape of the sphere 200.
Specifically, for example, by executing the shape measurement program 83b7, the CPU 81 executes one of the cross-sectional shapes of the sphere 200 by executing the cross-sectional shape calculation program 83b1 each time the sphere 200 is rotated at a predetermined angle by the rotary table 30. As shown in FIG. 4, the center position (the center of the circle) is obtained for each of the plurality of cross-sectional shapes of the calculated sphere 200. Then, the shape of the sphere 200 is measured based on the three-dimensional shape obtained by synthesizing the cross-sectional shapes so that the respective center positions match.
The CPU 81 functions as a shape measuring unit by executing the shape measuring program 83b7.

[How to obtain correction data table]
Next, a method for obtaining the correction amount data table 83a of the shape measuring apparatus 100 according to the first embodiment will be described with reference to FIG.

  First, in step S1, for example, as shown in FIG. 2, the sphere 200 attached to the rotary table 30 is set to a predetermined reference position.

  Next, in step S <b> 2, the CPU 81 calculates one cross-sectional shape (for example, a diameter) that serves as a reference of the sphere 200 by executing the cross-sectional shape calculation program 83 b 1.

  Next, in step S3, the CPU 81 drives the slider 22 of the moving mechanism 20 to move the sphere 200 from a predetermined reference position by a predetermined movement amount (for example, ± 5 μm). In step S4, the CPU 81 again By executing the cross-sectional shape calculation program 83b1, one cross-sectional shape of the sphere 200 is calculated.

  Next, in step S5, when the CPU 81 determines that the predetermined distance (for example, ± 35 μm) has been accumulated from the predetermined reference position and moved (step S5; Yes), the process proceeds to step S6. On the other hand, when it is determined that the predetermined distance from the predetermined reference position is not moved (step S5; No), the process returns to step S3.

  Next, in step S6, the CPU 81 starts from the reference position of the sphere 200 based on one cross-sectional shape of the sphere 200 calculated by executing the cross-sectional shape calculation program 83b1 at each position moved from the predetermined reference position. The magnification information of the cross-sectional shape of the sphere 200 corresponding to the amount of deviation in the optical axis direction is stored, and this processing is terminated.

[Shape measurement processing]
Next, a method for measuring the shape of the sphere 200 by the shape measuring apparatus 100 according to the first embodiment will be described with reference to FIG.

  First, in step S11, for example, as shown in FIG. 1, the sphere 200 attached to the turntable 30 is set to a predetermined reference position.

  Next, in step S12, the CPU 81 calculates one cross-sectional shape of the sphere 200 by executing the cross-sectional shape calculation program 83b1.

  Next, in step S13, the CPU 81 rotates the rotary table 30 by a predetermined angle. In step S14, the CPU 81 executes the cross-sectional shape calculation program 83b1 again to calculate one cross-sectional shape of the sphere 200.

Next, in step S15, the CPU 81 executes the position measurement program 83b4 to measure the amount of deviation of the sphere 200 from the predetermined reference position in the optical axis direction based on the center position of the sphere 200.
More specifically, for example, the CPU 81 calculates the one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the second imaging unit 70 by executing the second cross-sectional shape calculation program 83b2. Then, the CPU 81 executes the center position calculation program 83b3, thereby calculating the center position of the sphere 200 based on the one cross-sectional shape calculated by the execution of the second cross-sectional shape calculation program 83b2. The amount of deviation in the optical axis direction from the reference position is measured.

  Next, in step S16, the CPU 81 executes the enlargement magnification information extraction program 83b5, thereby enlarging the sphere 200 measured by the execution of the position measurement program 83b4 and corresponding to the amount of deviation in the optical axis direction from the predetermined reference position. The magnification information is extracted from the correction amount data table 83a.

  Next, in step S17, the CPU 81 is calculated by executing the cross-sectional shape calculation program 83b1 based on the enlargement magnification information extracted by executing the enlargement magnification information extraction program 83b5 by executing the cross-sectional shape correction program 83b6. Correct the cross-sectional shape.

  Next, in step S18, the CPU 81 determines whether or not the cross-sectional shape of the sphere 200 has been acquired, and when the CPU 81 determines that the cross-sectional shape of the sphere 200 has been acquired (step S18; Yes), step S19. Migrate to On the other hand, when it is determined that the cross-sectional shape of the sphere 200 has not been acquired (step S18; No), the process returns to step S13.

  Next, in step S19, the CPU 81 executes the shape measurement program 83b7, thereby calculating one cross-sectional shape of the sphere 200 by executing the cross-sectional shape calculation program 83b1 every time the sphere 200 is rotated at a predetermined angle by the rotary table 30. Then, as shown in FIG. 4, the shape of the sphere 200 is measured based on the calculated cross-sectional shapes of the sphere 200, and the present process ends.

Thus, according to the shape measuring apparatus 100 of the first embodiment, the moving mechanism 20 that holds the sphere 200 at a predetermined reference position, and the light source unit that irradiates the sphere 200 held by the moving mechanism 20 with light. 10, a first imaging unit 50 that captures a map formed by irradiating the sphere 200 held by the moving mechanism 20 with the light output from the light source unit 10, and the light intensity of the map captured by the first imaging unit 50 The cross-sectional shape calculation program 83b1 that calculates one cross-sectional shape of the sphere 200 from the distribution, the rotary table 30 that rotates the sphere 200 at a predetermined angle around the rotational symmetry axis of the sphere 200, and the rotary table 30 that makes the sphere 200 a predetermined angle Each time it is rotated, the cross-sectional shape calculation program 83b1 is executed to calculate one cross-sectional shape of the sphere 200, and the calculated cross-sectional shapes of the sphere 200 A shape measurement program 83b7 for measuring the shape of the body 200, and the correction amount data table 83a can store magnification information corresponding to the amount of deviation in the optical axis direction from the reference position of the sphere 200. Can measure the amount of deviation in the optical axis direction from the reference position of the sphere 200 by executing the position measurement program 83b4, and the CPU 81 can measure the position measurement program by executing the magnification information extraction program 83b5. Based on the deviation amount in the optical axis direction from the reference position of the sphere 200 measured by the execution of 83b4, the magnification information corresponding to the deviation amount can be extracted from the correction amount data table 83a. By executing the correction program 83b6, an enlargement magnification information extraction program Based on the magnification information extracted by the execution of 3b5, it is possible to correct an sectional shape calculated by executing the cross-sectional shape calculation program 83B1.
Therefore, when the sphere 200 is rotated around the rotational symmetry axis of the sphere 200 by the rotary table 30, the sphere 200 is displaced from the reference position due to an error in rotational motion or an error in eccentricity, and is calculated by executing the cross-sectional shape calculation program 83b1. Even when an error occurs in the cross-sectional shape of the sphere 200, the cross-sectional shape can be corrected based on the amount of deviation in the optical axis direction from the reference position of the sphere 200, and more accurate shape measurement is possible. It can be performed.
In addition, a moving mechanism 20 that moves the sphere 200 in the optical axis direction of the light output from the light source unit 10 is provided, and the sphere 200 is moved from the reference position to the optical axis direction by the moving mechanism 20 by the correction amount data table 83a. Each time the movement amount is moved, one cross-sectional shape of the sphere 200 is calculated by executing the cross-sectional shape calculation program 83b1, and the one cross-sectional shape of the sphere 200 calculated by executing the movement amount of the sphere 200 and the cross-sectional shape calculation program 83b1. Based on these dimensions, it is possible to store magnification information corresponding to the amount of deviation in the optical axis direction from the reference position of the sphere 200 for correcting the deviation in focus when measuring the cross-sectional shape.
Therefore, the magnification information corresponding to the amount of deviation in the optical axis direction from the reference position of the object to be measured for correcting the deviation in focus can be stored based on the sphere 200 that is actually the object of shape measurement. Thus, shape measurement with higher accuracy can be performed.
Furthermore, the second imaging unit 70 can image the sphere 200 from the direction intersecting the optical axis direction of the light output from the light source unit 10, and the CPU 81 executes the second cross-sectional shape calculation program 83b2. Thus, one cross-sectional shape of the sphere 200 can be calculated from the light intensity distribution of the mapping imaged by the second imaging unit 70, and the CPU 81 calculates the second cross-sectional shape by executing the center position calculation program 83b3. The center position of the sphere 200 can be calculated based on the cross-sectional shape calculated by the execution of the program 83b2, and the center position of the sphere 200 calculated by the execution of the center position calculation program 83b3 can be calculated by executing the position measurement program 83b4. Based on this, it is possible to measure the amount of deviation in the optical axis direction from the reference position of the sphere 200.
Therefore, when the sphere 200 is rotated around the rotational symmetry axis of the sphere 200 by the rotary table 30, even if the sphere 200 is deviated from the reference position due to an error in rotational motion or an error in eccentricity, the light source unit 10 The amount of deviation in the optical axis direction from the reference position of the sphere 200 can be measured from the direction intersecting the optical axis direction of the light output from the sphere 200, and when the sphere 200 is rotated based on the amount of deviation. The error of the rotational motion and the error of the eccentricity can be suitably corrected.

Second Embodiment
Next, a shape measuring apparatus 300 according to the second embodiment of the present invention will be described with reference to FIG. The basic configuration of the second embodiment is the same as that of the first embodiment, and only differences from the configuration of the first embodiment will be described.

  For example, as shown in FIG. 5, the image processing unit 380 includes a CPU (Central Processing Unit) 81, a RAM (Random Access Memory) 82, a storage unit 383, a display unit 84 that displays an image processing result, and the like. By executing a predetermined program stored in the storage unit 383, there is a function of performing operation control of each unit based on predetermined operation conditions set in advance in order to perform a predetermined operation.

  The storage unit 383 has, for example, a storage medium (not shown) in which programs, data, and the like are stored in advance, and this storage medium is configured by, for example, a semiconductor memory. The storage unit 383 stores various data for the CPU 81 to perform image processing, various processing programs, data processed by executing these programs, and the like. More specifically, for example, as shown in FIG. 7, the storage unit 383 includes a cross-sectional shape calculation program 383 b 1, a second cross-sectional shape calculation program 383 b 2, a center position calculation program 383 b 3, a position measurement program 383 b 4, a drive control program 383 b 5, A shape measurement program 383b6 and the like are stored.

The cross-sectional shape calculation program 383b1 is a program that causes the CPU 81 to realize a function of calculating one cross-sectional shape of the sphere 200.
Specifically, for example, the CPU 81 executes the cross-sectional shape calculation program 383b1, thereby calculating one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the first imaging unit 50.
The CPU 81 functions as a cross-sectional shape calculating unit by executing the cross-sectional shape calculating program 383b1.

The second cross-sectional shape calculation program 383b2 is a program that causes the CPU 81 to realize a function of calculating one cross-sectional shape of the sphere 200.
Specifically, for example, the CPU 81 calculates the one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the second imaging unit 70 by executing the second cross-sectional shape calculation program 383b2.
The CPU 81 functions as a second cross-sectional shape calculating unit by executing the second cross-sectional shape calculating program 383b2.

The center position calculation program 383b3 is a program that causes the CPU 81 to realize a function of calculating the center position of the sphere 200.
Specifically, for example, the CPU 81 executes the center position calculation program 383b3 to calculate the center position of the sphere 200 based on the one cross-sectional shape calculated by the execution of the second cross-sectional shape calculation program 383b2.
The CPU 81 functions as a center position calculation unit by executing the center position calculation program 383b3.

The position measurement program 383b4 is a program that causes the CPU 81 to realize a function of measuring the amount of deviation of the sphere 200 from the predetermined reference position in the optical axis direction.
Specifically, for example, the CPU 81 executes the position measurement program 383 b 4 to measure the amount of deviation in the optical axis direction from the reference position of the sphere 200 based on the center position of the sphere 200.
More specifically, for example, the CPU 81 executes a second cross-sectional shape calculation program 383b2 described later, thereby calculating one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the second imaging unit 70. . Then, the CPU 81 executes the center position calculation program 383b3, thereby calculating the center position of the sphere 200 based on the one cross-sectional shape calculated by the execution of the second cross-sectional shape calculation program 383b2. The amount of deviation in the optical axis direction from the position is measured.
The CPU 81 functions as a position measurement unit by executing the position measurement program 383b4.

The drive control program 383b5 is a program that causes the CPU 81 to realize a function of driving and controlling the slider 22 of the moving mechanism 20 to a predetermined position.
Specifically, for example, the CPU 81 executes the driving control program 383b5, and thereby based on the amount of deviation in the optical axis direction from the predetermined reference position of the sphere 200 measured by the execution of the position measurement program 383b4. The slider 22 of the moving mechanism 20 is driven so that 200 coincides with a predetermined reference position.

The shape measurement program 383b6 is a program that causes the CPU 81 to realize a function of measuring the shape of the sphere 200.
Specifically, for example, by executing the shape measurement program 383b6, the CPU 81 executes one of the cross-sectional shapes of the sphere 200 by executing the cross-sectional shape calculation program 383b1 each time the sphere 200 is rotated at a predetermined angle by the rotary table 30. As shown in FIG. 4, the center position (the center of the circle) is obtained for each of the plurality of cross-sectional shapes of the calculated sphere 200. Then, the shape of the sphere 200 is measured based on the three-dimensional shape obtained by synthesizing the cross-sectional shapes so that the respective center positions match.
The CPU 81 functions as a shape measuring unit by executing the shape measuring program 383b6.

[Shape measurement processing]
Next, a method for measuring the shape of the sphere 200 by the shape measuring apparatus 300 according to the second embodiment will be described with reference to FIG.

  First, in step S21, for example, as shown in FIG. 5, the sphere 200 attached to the rotary table 30 is set to a predetermined reference position.

  Next, in step S22, the CPU 81 calculates one cross-sectional shape of the sphere 200 by executing the cross-sectional shape calculation program 383b1.

  Next, in step S23, the CPU 81 rotates the turntable 30 at a predetermined angle.

Next, in step S <b> 24, the CPU 81 executes the position measurement program 383 b 4 to measure the amount of deviation in the optical axis direction from the reference position of the sphere 200 based on the center position of the sphere 200.
More specifically, for example, the CPU 81 calculates the one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the second imaging unit 70 by executing the second cross-sectional shape calculation program 383b2. Then, the CPU 81 executes the center position calculation program 383b3, thereby calculating the center position of the sphere 200 based on the one cross-sectional shape calculated by the execution of the second cross-sectional shape calculation program 383b2. The amount of deviation in the optical axis direction from the position is measured.

  Next, in step S25, the CPU 81 executes the drive control program 383b5, so that the sphere 200 is based on the amount of deviation in the optical axis direction from the reference position of the sphere 200 measured by the execution of the position measurement program 383b4. The slider 22 of the moving mechanism 20 is driven so as to match the position.

  Next, in step S <b> 26, the CPU 81 executes the cross-sectional shape calculation program 383 b <b> 1 again to calculate one cross-sectional shape of the sphere 200.

  Next, in step S27, the CPU 81 determines whether or not the cross-sectional shape of the sphere 200 has been acquired, and when the CPU 81 determines that the cross-sectional shape of the sphere 200 has been acquired (step S27; Yes), step S28. Migrate to On the other hand, when it is determined that the cross-sectional shape of the sphere 200 has not been acquired (step S27; No), the process returns to step S23.

  Next, in step S28, the CPU 81 executes the shape measurement program 383b6 to calculate one cross-sectional shape of the sphere 200 by executing the cross-sectional shape calculation program 383b1 each time the sphere 200 is rotated by a predetermined angle by the rotary table 30. Then, as shown in FIG. 4, the shape of the sphere 200 is measured based on the calculated cross-sectional shapes of the sphere 200, and the present process ends.

As described above, according to the shape measuring apparatus 300 of the second embodiment, the moving mechanism 20 that holds the sphere 200 at a predetermined reference position, and the light source unit that irradiates the sphere 200 held by the moving mechanism 20 with light. 10, a moving mechanism 20 that moves the sphere 200 in the optical axis direction of the light output from the light source unit 10, and a mapping formed by irradiating the sphere 200 held by the moving mechanism 20 with the light output from the light source unit 10. A first imaging unit 50 that captures the image, a cross-sectional shape calculation program 383b1 that calculates one cross-sectional shape of the sphere 200 from the light intensity distribution of the mapping imaged by the first imaging unit 50, and a sphere about the rotational symmetry axis of the sphere 200 By rotating the rotary table 30 for rotating 200 at a predetermined angle, and executing the cross-sectional shape calculation program 383b1 each time the sphere 200 is rotated at a predetermined angle by the rotary table 30. A shape measurement program 383b6 that calculates one cross-sectional shape of the sphere 200 and measures the shape of the sphere 200 based on the calculated cross-sectional shapes of the sphere 200, and the CPU 81 executes the position measurement program 383b4. The amount of deviation in the optical axis direction from the reference position of the sphere 200 can be measured, and the CPU 81 executes the drive control program 383b5, and based on the amount of deviation measured by the execution of the position measurement program 383b4, The moving mechanism 20 can be driven so that the sphere 200 coincides with the reference position.
Therefore, when the sphere 200 is rotated around the rotational symmetry axis of the sphere 200 by the rotary table 30, even if the sphere 200 is deviated from the reference position due to an error in rotational motion or an error in eccentricity, Since the amount of deviation in the optical axis direction from the reference position is measured, and based on the measured amount of deviation, the moving mechanism 20 can be driven so that the sphere 200 matches the reference position. It can be performed.
Further, the second imaging unit 70 can image the sphere 200 from the direction intersecting the optical axis direction of the light output from the light source unit 10, and the CPU 81 executes the second cross-sectional shape calculation program 383b2. Thus, one cross-sectional shape of the sphere 200 can be calculated from the light intensity distribution of the map imaged by the second imaging unit 70, and the CPU 81 calculates the second cross-sectional shape by executing the center position calculation program 383b3. The center position of the sphere 200 can be calculated based on the cross-sectional shape calculated by the execution of the program 383b2, and the center position of the sphere 200 calculated by the execution of the center position calculation program 383b3 can be calculated by executing the position measurement program 383b4. Based on this, the amount of deviation in the optical axis direction from the reference position of the sphere 200 can be measured. Kill.
Therefore, when the sphere 200 is rotated around the rotational symmetry axis of the sphere 200 by the rotary table 30, even if the sphere 200 is deviated from the reference position due to an error in rotational motion or an error in eccentricity, the light source unit 10 The amount of deviation in the optical axis direction from the reference position of the sphere 200 can be measured from the direction intersecting the optical axis direction of the light output from the sphere 200, and when the sphere 200 is rotated based on the amount of deviation. The error of the rotational motion and the error of the eccentricity can be suitably corrected.

The present invention is not limited to the above embodiment, and the object to be measured may be a rotationally symmetric body, and may be a cylinder, a cone, or the like.
Further, the arrangement of the second imaging means is not limited to the direction intersecting the optical axis direction of the light output from the light source unit, but may be a position where the movement amount of the measured object in the optical axis direction can be measured.
In addition, when the amount of deviation in the optical axis direction from the predetermined reference position of the measured object measured by the position measuring means exceeds a preset threshold, it indicates that the amount of deviation exceeds a preset threshold. The design may be provided with an informing means for informing.

In the second embodiment, when the sphere 200 is moved so that the sphere 200 matches the reference position, the moving mechanism 20 is driven by executing the drive control program 383b5. However, the present invention is not limited to this. First, the moving mechanism 20 may be driven manually so that the sphere 200 coincides with the reference position based on the amount of deviation measured by the execution of the position measurement program 383b4.
In addition, it is needless to say that other specific detailed structures can be appropriately changed.

It is the schematic which shows the structure of the shape measuring apparatus of 1st Embodiment which concerns on this invention. It is the schematic explaining the method to acquire a correction amount data table in the shape measuring apparatus of 1st Embodiment which concerns on this invention. It is a figure which shows an example of the correction amount data table in the shape measuring apparatus of 1st Embodiment which concerns on this invention. It is a conceptual diagram which shows the shape measuring method in the shape measuring apparatus which concerns on this invention. It is a flowchart figure which shows the correction amount data table acquisition method in the shape measuring apparatus of 1st Embodiment which concerns on this invention. It is a flowchart figure which shows the shape measuring method in the shape measuring apparatus of 1st Embodiment which concerns on this invention. It is the schematic which shows the structure of the shape measuring apparatus of 2nd Embodiment which concerns on this invention. It is a flowchart figure which shows the shape measuring method in the shape measuring apparatus of 2nd Embodiment which concerns on this invention. It is the schematic which shows the structure of the shape measuring apparatus in a prior art. It is the schematic which shows the structure of the shape measuring apparatus in a prior art.

Explanation of symbols

10 light source 20 moving mechanism (holding means)
30 rotary table (rotating means)
40 1st objective lens 50 1st imaging part (imaging means)
60 Second objective lens 70 Second imaging unit (second imaging means)
80 Image processing unit 81 CPU (cross-sectional shape calculating means, second cross-sectional shape calculating means, center position calculating means, position measuring means, magnification information extracting means, cross-sectional shape correcting means, shape measuring means)
83 storage unit 83a correction amount data table (correction amount storage means)
83b1 Cross-sectional shape calculation program (cross-sectional shape calculation means)
83b2 Second sectional shape calculation program (second sectional shape calculation means)
83b3 Center position calculation program (center position calculation means)
83b4 Position measurement program (position measurement means)
83b5 Enlargement magnification information extraction program (enlargement magnification information extraction means)
83b6 Cross-sectional shape correction program (cross-sectional shape correction means)
83b7 Shape measurement program (shape measurement means)
100 shape measuring apparatus (first embodiment)
200 Sphere (object to be measured)
300 Shape measuring device (second embodiment)
380 Image processing unit 383 storage unit 383b1 cross-sectional shape calculation program (cross-sectional shape calculation means)
383b2 Second sectional shape calculation program (second sectional shape calculation means)
383b3 Center position calculation program (center position calculation means)
383b4 Position measurement program (position measurement means)
383b5 drive control program 383b6 shape measurement program (shape measurement means)

Claims (5)

In a shape measuring apparatus that measures the cross-sectional shape of a measurement object that is a rotationally symmetric body and measures the shape of the measurement object,
Holding means for holding the object to be measured at a predetermined reference position;
A light source unit for irradiating the object to be measured held by the holding unit with light;
An imaging unit that captures a map formed by irradiating the object to be measured held by the holding unit with the light output from the light source unit;
A cross-sectional shape calculating means for calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
Rotating means for rotating the object to be measured at a predetermined angle around the rotational symmetry axis of the object to be measured;
Each time the object to be measured is rotated at a predetermined angle by the rotating means, a cross-sectional shape of the object to be measured is calculated by the cross-sectional shape calculating means, and the object to be measured is calculated based on the calculated plurality of cross-sectional shapes of the object to be measured. A shape measuring means for measuring the shape of the measuring object;
With
The cross-sectional shape calculating means
Correction amount storage means for storing magnification information corresponding to the amount of deviation in the optical axis direction from the reference position of the object to be measured;
Position measuring means for measuring a deviation amount of the object to be measured from the reference position in the optical axis direction;
Based on the amount of deviation of the measured object from the reference position in the optical axis direction measured by the position measuring means, the magnification information extracting means extracts the magnification information corresponding to the deviation amount from the correction amount storage means. When,
A cross-sectional shape correcting means for correcting one cross-sectional shape calculated by the cross-sectional shape calculating means based on the magnification information extracted by the magnification information extracting means;
A shape measuring apparatus comprising: A moving mechanism for moving the object to be measured in an optical axis direction of light output from the light source unit;
The correction amount storage means includes
The cross-sectional shape calculating means calculates one cross-sectional shape of the measured object every time the moving mechanism moves the measured object from the reference position in the optical axis direction by the moving mechanism. Based on the amount of movement and the size of one cross-sectional shape of the measured object calculated by the cross-sectional shape calculating means, from the reference position of the measured object for correcting a focus shift when measuring the cross-sectional shape 2. The shape measuring apparatus according to claim 1, wherein enlargement magnification information corresponding to the amount of deviation in the optical axis direction is stored. In a shape measuring apparatus that measures the cross-sectional shape of a measurement object that is a rotationally symmetric body and measures the shape of the measurement object,
Holding means for holding the object to be measured at a predetermined reference position;
A light source unit for irradiating the object to be measured held by the holding unit with light;
A moving mechanism for moving the object to be measured in an optical axis direction of light output from the light source unit;
An imaging unit that captures a map formed by irradiating the object to be measured held by the holding unit with the light output from the light source unit;
A cross-sectional shape calculating means for calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
Rotating means for rotating the object to be measured at a predetermined angle around the rotational symmetry axis of the object to be measured;
Each time the object to be measured is rotated at a predetermined angle by the rotating means, a cross-sectional shape of the object to be measured is calculated by the cross-sectional shape calculating means, and the object to be measured is calculated based on the calculated plurality of cross-sectional shapes of the object to be measured. A shape measuring means for measuring the shape of the measuring object;
With
The cross-sectional shape calculating means
A shape measuring apparatus comprising position measuring means for measuring a deviation amount in the optical axis direction from a reference position of the object to be measured. Second imaging means for imaging the object to be measured from a direction intersecting an optical axis direction of light output from the light source unit;
Second cross-sectional shape calculating means for calculating one cross-sectional shape of the object to be measured from the light intensity distribution of the map imaged by the second imaging means;
Center position calculating means for calculating a center position of the object to be measured based on the cross-sectional shape calculated by the second cross-sectional shape calculating means;
With
The position measuring means includes
4. The amount of deviation in the optical axis direction from the reference position of the object to be measured is measured based on the center position of the object to be measured calculated by the center position calculating means. The shape measuring apparatus according to one item.   The shape measuring apparatus according to claim 1, wherein the object to be measured is a sphere.

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