JP2008102123A - Shape measurement method and shape measurement device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shape measurement method and a shape measurement device for easily and efficiently carrying out shape measurement. <P>SOLUTION: An imaging part 50 takes an image of a ring of light formed when light emitted from a light source part 10 is projected to an object 200 to be measured through an aperture 20, and an image processing part 60 calculates one cross-sectional shape of the object 200 to be measured based on a light intensity distribution of the taken image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shape measuring method and a shape measuring device.

Conventionally, as a probe (probe) for a coordinate measuring machine or the like, a probe having a rod-shaped shaft portion and a contact ball provided at the tip of the shaft portion is used. And the probe processing method and processing machine which process the probe which has a fine tip sphere with which measurement sensitivity becomes favorable are known (refer to patent documents 1).
JP 2005-96033 A

  However, in the case of the above prior art, even if a probe having a fine tip sphere can be processed, it cannot be performed until the sphericity of the fine tip sphere is measured. Degree measurement is the key to improving the accuracy of minute probing systems that are expected to develop in the future.

  An object of the present invention is to provide a shape measuring method and a shape measuring apparatus that can perform shape measurement simply and efficiently.

In order to solve the above problems, the invention described in claim 1
In the shape measuring method for measuring the shape of the object to be measured which is a rotationally symmetric body,
Arranging an aperture having an opening larger than the outer shape of the object to be measured on the optical axis and the object to be measured;
Imaging a map formed by irradiating the object to be measured with light by imaging means;
Calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
It is characterized by providing.

The invention according to claim 2 is the shape measuring method according to claim 1,
A magnifying lens for enlarging the mapping is disposed between the aperture and the object to be measured and an imaging surface of the imaging means, and the mapping is captured.

The invention according to claim 3 is the shape measuring method according to claim 1,
A telecentric lens is disposed between the aperture and the object to be measured and an imaging surface of the imaging means to capture the mapping.

The invention according to claim 4
In the shape measuring method according to any one of claims 1 to 3,
The light is scattered light.

The invention described in claim 5
In the shape measuring method according to any one of claims 1 to 3,
The light is parallel light.

The invention described in claim 6
In the shape measuring method for measuring the shape of the object to be measured which is a rotationally symmetric body,
From the light source unit side on the optical axis between the light source unit and the imaging surface of the imaging unit, from the outer shape of the measured object to the image forming position of the measured object, the first lens, and the first lens An aperture having a larger aperture, and a step of arranging the second lens in that order;
Imaging the map formed by irradiating the object to be measured with light from the light source unit with the imaging means;
Calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
It is characterized by providing.

The invention described in claim 7
In the shape measuring method for measuring the shape of the object to be measured which is a rotationally symmetric body,
An aperture, a first lens, and an image of the first lens having an opening larger than the outer shape of the object to be measured on the optical axis from the light source unit side between the light source unit and the imaging surface of the imaging unit. Arranging the object to be measured and the second lens in order at a position;
Imaging the map formed by irradiating the object to be measured with light from the light source unit with the imaging means;
Calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
It is characterized by providing.

The invention according to claim 8 provides:
In the shape measuring method according to claim 6 or 7,
The first lens and / or the second lens is a telecentric lens unit.

The invention according to claim 9 is:
In the shape measuring method according to any one of claims 6 to 8,
An aperture diameter suitable for the object to be measured is selected by changing a magnification of the first lens and / or the second lens.

The invention according to claim 10 is:
In the shape measuring method according to any one of claims 1 to 9,
Rotating the object to be measured by a predetermined angle;
Alternately calculating a cross-sectional shape of the object to be measured and a step of rotating the object to be measured at a predetermined angle to calculate a cross-sectional shape of the entire surface of the object to be measured;
It is characterized by providing.

The invention according to claim 11
In the shape measuring method according to any one of claims 1 to 10,
The object to be measured is a sphere.

The invention according to claim 12
The shape measuring method according to claim 11,
The step of calculating one cross-sectional shape of the sphere includes:
By collecting the light intensity pattern of the map imaged by the imaging means on an orthogonal coordinate axis to determine a temporary center, and detecting the edge of the bright spot in a predetermined azimuth direction with the center as the origin, the sphere Edge and the edge of the aperture,
By comparing the shape calculated from the detected edge of the aperture with the predetermined aperture shape of the aperture, the shape calculated from the edge of the aperture is corrected, and based on the correction amount accompanying the correction, The shape measuring method according to claim 11, wherein the cross-sectional shape of the sphere is calculated by correcting the shape of the detected edge of the sphere.

The invention according to claim 13
The shape measuring method according to claim 12,
13. The shape measuring method according to claim 12, wherein the roundness in one section of the sphere is calculated based on the calculated one section shape of the sphere.

The invention according to claim 14
The shape measuring method according to claim 13,
The roundness is obtained at a predetermined rotation angle on the entire circumferential surface of the sphere, and the sphericity of the sphere is calculated based on variations in the roundness value.

The invention according to claim 15 is:
In a shape measuring device that measures the shape of a measured object that is a rotationally symmetric body,
A light source unit for irradiating the object to be measured with light;
An aperture disposed on the optical axis of light output from the light source unit and having an opening larger than the outer shape of the object to be measured;
Imaging means for imaging a map formed by irradiating the object to be measured disposed on the optical axis with 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;
It is characterized by providing.

The invention described in claim 16
The shape measuring apparatus according to claim 15,
A magnifying lens for magnifying the mapping is provided between the aperture, the object to be measured, and an imaging surface of the imaging means.

The invention described in claim 17
The shape measuring apparatus according to claim 15,
A telecentric lens is provided between the aperture and the object to be measured, and an imaging surface of the imaging means.

The invention described in claim 18
In the shape measuring device according to any one of claims 15 to 17,
The light source unit includes scattering means for scattering and outputting light.

The invention according to claim 19 is
In the shape measuring device according to any one of claims 15 to 17,
The light source unit includes parallel means for outputting light in parallel.

The invention according to claim 20 provides
In a shape measuring device that measures the shape of a measured object that is a rotationally symmetric body,
A light source unit for irradiating the object to be measured with light;
First and second lenses that pass a map of the object to be measured by the light emitted by the light source unit;
An aperture disposed at an imaging position of the first lens between the first lens and the second lens and having an opening larger than an outer shape of the object to be measured;
Imaging means for imaging a map emitted from the second lens;
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;
It is characterized by providing.

The invention according to claim 21
In a shape measuring device that measures the shape of a measured object that is a rotationally symmetric body,
A light source unit for irradiating the object to be measured with light;
An aperture having an opening larger than the outer shape of the object to be measured, and an aperture through which the light irradiated by the light source unit passes through the opening;
First and second lenses for passing light that has passed through the aperture;
The second lens is disposed on the opposite side of the first lens, and is disposed at an imaging position of the first lens between the first lens and the second lens. An imaging means for imaging a map of the measured object;
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;
It is characterized by providing.

The invention described in claim 22
In the shape measuring device according to claim 20 or 21,
The first lens and / or the second lens is a telecentric lens unit.

The invention according to claim 23 provides
In the shape measuring device according to any one of claims 20 to 22,
An aperture diameter of an appropriate aperture for the object to be measured can be selected by changing the magnification of the first lens and / or the second lens.

The invention according to claim 24 provides
In the shape measuring device according to any one of claims 15 to 23,
Rotating means for rotating the object to be measured at a predetermined angle;
A shape that calculates one cross-sectional shape of the object to be measured by the cross-sectional shape calculating means each time the object to be measured is rotated by a predetermined angle by the rotating means, and calculates a cross-sectional shape on the entire circumference of the object to be measured. Measuring means;
It is characterized by providing.

The invention according to claim 25 provides
In the shape measuring device according to any one of claims 15 to 24,
The object to be measured is a sphere.

According to the first aspect of the present invention, the aperture having a larger opening than the outer shape of the object to be measured and the object to be measured are arranged on the optical axis, so that the cross-sectional shape of the object to be measured is obtained by the imaging unit. A ring of light that can be formed in the surroundings can be imaged, and a cross-sectional shape of the object to be measured can be calculated from the light intensity distribution of the ring of light.
Accordingly, the diffraction of light is suppressed, and the edge of the object to be measured can be detected from the light intensity distribution of the imaged light ring, and the shape of the object to be measured can be measured easily and efficiently. .

According to the second aspect of the present invention, it is of course possible to obtain the same effect as that of the first aspect of the invention, and a magnifying lens is provided between the aperture and the object to be measured and the imaging surface of the imaging means. Can be placed.
Accordingly, a mapping can be taken through the magnifying lens, and shape measurement can be performed easily and efficiently even when the object to be measured is very small.

According to the invention described in claim 3, it is needless to say that the same effect as that of the invention described in claim 1 can be obtained. A telecentric lens is provided between the aperture and the object to be measured and the imaging surface of the imaging means. Can be placed.
Therefore, only the parallel light parallel to the optical axis among the light emitted from the light source can be set as the object of image formation, and the error of the image size can be suppressed. In addition, light diffraction can be relaxed.

According to the invention described in claim 4, it is needless to say that the same effect as in the invention described in any one of claims 1 to 3 can be obtained, and the object to be measured can be irradiated with scattered light. it can.
Therefore, the diffraction of light can be made inconspicuous, and the shape of the measured object can be measured easily and efficiently.

According to the invention described in claim 5, it is needless to say that the same effect as in the invention described in any one of claims 1 to 3 can be obtained, and the object to be measured can be irradiated with parallel light. it can.
Therefore, since the light emitted from the light source can be condensed as parallel light, the entire diffraction pattern becomes brighter, the contrast becomes stronger, the diffraction spread angle is smaller than that of a point light source, and an easy-to-handle diffraction pattern is obtained. It is done.

According to the invention described in claim 6, between the light source unit and the imaging surface of the imaging unit, the object to be measured, the first lens, and the imaging position of the first lens on the optical axis from the light source unit side. An aperture having an opening larger than the outer shape of the object to be measured and the second lens are arranged in this order.
Therefore, the edge of the object to be measured can be detected from the light intensity distribution of the picked-up light ring, and the shape of the object to be measured can be measured easily and efficiently. Further, measurement can be performed without depending on the distance between the measured object and the aperture, and physical interference between the measured object and the aperture can be suitably prevented. Further, the size of the image of the object to be measured can be set by the magnification of the first lens, and the degree of freedom of the aperture diameter of the aperture can be increased accordingly.

According to the seventh aspect of the invention, the aperture and the first lens having an opening larger than the outer shape of the object to be measured from the light source unit side on the optical axis between the light source unit and the imaging surface of the imaging unit. The object to be measured and the second lens are arranged in this order at the imaging position of the first lens.
Therefore, the edge of the object to be measured can be detected from the light intensity distribution of the picked-up light ring, and the shape of the object to be measured can be measured easily and efficiently. Further, measurement can be performed without depending on the distance between the measured object and the aperture, and physical interference between the measured object and the aperture can be suitably prevented. Further, the size of the image of the object to be measured can be set by the magnification of the second lens, and the degree of freedom of the aperture diameter of the aperture can be increased accordingly.
Further, by arranging the aperture on the light source unit side with respect to the object to be measured, it is possible to prevent light from being scattered when the light output from the light source unit is irradiated on the object to be measured. The utilization efficiency of the light irradiated from can be increased.

According to the invention described in claim 8, it is needless to say that the same effect as that of the invention described in claim 6 or 7 can be obtained, and the first lens and / or the second lens is replaced with a telecentric lens. Can be a unit.
Therefore, by using a telecentric lens unit, the position of the aperture is located at the focal position of the lens, and by reducing the aperture, much light from the object to be measured is blocked by the aperture, and light that forms an image The position of the object to be measured is that only the light that has passed through the aperture through the focal point after entering the lens from the object to be measured to be approximately parallel to the optical axis, and only the substantially parallel light from the object to be measured is involved in image formation. Fluctuation in magnification due to changes in is small.
Therefore, it is possible to suppress a change in the enlargement magnification due to the displacement of the object to be measured. In addition, light diffraction can be relaxed.

According to the ninth aspect of the invention, it is needless to say that the same effect as that of the sixth aspect of the invention can be obtained, and that the first lens and / or the second lens are By changing the magnification, it is possible to select an appropriate aperture diameter for the object to be measured.
Therefore, by changing the magnification of the lens, the aperture diameter of the aperture can be adjusted, and it is not necessary to prepare an aperture corresponding to the size of the object to be measured each time. It can be performed.

According to the invention described in claim 10, it is needless to say that the same effect as in the invention described in any one of claims 1-9 can be obtained, and the object to be measured can be rotated at a predetermined angle. it can.
Accordingly, the step of calculating the cross-sectional shape of the object to be measured and the step of rotating the object to be measured by a predetermined angle can be alternately repeated, and the cross-sectional shape of the entire surface of the object to be measured can be easily and efficiently performed. It can be measured well.

  According to the invention described in claim 11, it is needless to say that the same effect as that of the invention described in any one of claims 1 to 10 can be obtained, and the shape of a sphere can be measured easily and efficiently. It can be performed.

  According to the twelfth aspect of the present invention, it is needless to say that the same effect as that of the eleventh aspect of the invention can be obtained, and it is possible to easily and efficiently measure the cross-sectional shape of the sphere.

  According to the thirteenth aspect of the present invention, it is needless to say that the same effect as that of the twelfth aspect of the invention can be obtained, and the roundness of the sphere can be measured easily and efficiently. .

  According to the invention described in claim 14, it is needless to say that the same effect as that of the invention described in claim 13 can be obtained, and the sphericity of the sphere can be measured easily and efficiently. .

According to the fifteenth aspect of the present invention, the light source unit can irradiate the object to be measured with light, and when the object to be measured is irradiated with light, the aperture having an opening larger than the outer shape of the object to be measured is provided. Therefore, the diffraction of light can be suppressed, and the imaging unit can image a mapping formed by irradiating the object to be measured arranged on the optical axis with the light output from the light source unit. The shape calculation means can calculate the cross-sectional shape of the object to be measured from the light intensity distribution of the captured map.
Accordingly, the diffraction of light is suppressed, and the edge of the object to be measured can be detected from the light intensity distribution of the imaged light ring, and the shape of the object to be measured can be measured easily and efficiently. .

  According to the invention described in claim 16, it is needless to say that the same effect as that of the invention described in claim 15 can be obtained. A mapping is formed between the aperture and the object to be measured and the imaging surface of the imaging means. Since the magnifying lens for magnifying is provided, shape measurement can be performed easily and efficiently even when the object to be measured is very small.

  According to the invention described in claim 17, it is needless to say that the same effect as that of the invention described in claim 15 can be obtained. A telecentric lens is provided between the aperture and the object to be measured and the imaging surface of the imaging means. Therefore, only the parallel light parallel to the optical axis among the light irradiated from the light source can be set as the object of image formation, and the error of the image size can be suppressed. In addition, light diffraction can be relaxed.

According to the invention described in claim 18, it is needless to say that the same effect as in the invention described in any one of claims 15 to 17 can be obtained, and the light is scattered and outputted by the scattering means. Can do.
Therefore, the diffraction of light can be made inconspicuous, and the shape of the measured object can be measured easily and efficiently.

According to the nineteenth aspect of the invention, it is of course possible to obtain the same effect as that of any one of the fifteenth to seventeenth aspects of the invention, and the light is output in parallel by the parallel means. Can do.
Therefore, since the light output from the light source can be condensed as parallel light, it is possible to suppress a decrease in light intensity, to make the light diffraction inconspicuous, and more simply, In addition, the shape of the object to be measured can be measured efficiently.

According to the twentieth aspect, the light source unit can irradiate the object to be measured with light, and the first lens and the second lens can irradiate the object to be measured with the light irradiated by the light source unit. When the object to be measured is irradiated with light, the contour of the object to be measured can be converted into a map by passing through an aperture having an opening larger than the outer shape of the object to be measured. Thus, the map emitted from the second lens can be imaged, and the cross-sectional shape calculating unit can calculate the cross-sectional shape of the object to be measured from the light intensity distribution of the map imaged by the imaging unit.
Therefore, the edge of the object to be measured can be detected from the light intensity distribution of the picked-up light ring, and the shape of the object to be measured can be measured easily and efficiently. Further, measurement can be performed without depending on the distance between the measured object and the aperture, and physical interference between the measured object and the aperture can be suitably prevented. Further, the size of the image of the object to be measured is determined by the magnification of the first lens, and the degree of freedom of the aperture diameter of the aperture can be increased accordingly.

According to the twenty-first aspect of the present invention, the light source unit can irradiate the object to be measured with light, and the aperture allows the light irradiated by the light source unit to pass through the opening. And the second lens can pass the light that has passed through the aperture, and is measured by the imaging unit and disposed at the imaging position of the first lens between the first lens and the second lens. A mapping of an object can be taken.
Accordingly, as in the invention described in claim 20, the edge of the object to be measured can be detected from the light intensity distribution of the imaged light ring, and the shape of the object to be measured can be measured easily and efficiently. It can be carried out. Further, measurement can be performed without depending on the distance between the measured object and the aperture, and physical interference between the measured object and the aperture can be suitably prevented. Further, the size of the image of the object to be measured can be set by the magnification of the second lens, and the degree of freedom of the aperture diameter of the aperture can be increased accordingly.
Further, the positions of the object to be measured and the aperture are switched, and when the light output from the light source unit is irradiated onto the object to be measured, the light can be prevented from scattering, and the light emitted from the light source unit Can improve the use efficiency.

According to the invention described in claim 22, it is needless to say that the same effect as that of the invention described in claim 20 or 21 can be obtained, and the first lens and / or the second lens is replaced with a telecentric lens. Can be a unit.
Therefore, by using a telecentric lens unit, the position of the aperture is located at the focal position of the lens, and by reducing the aperture, much light from the object to be measured is blocked by the aperture, and light that forms an image The position of the object to be measured is that only the light that has passed through the aperture through the focal point after entering the lens from the object to be measured to be approximately parallel to the optical axis, and only the substantially parallel light from the object to be measured is involved in image formation. Fluctuation in magnification due to changes in is small.
Therefore, it is possible to suppress a change in the enlargement magnification due to the displacement of the object to be measured. In addition, light diffraction can be relaxed.

According to the invention of claim 23, it is needless to say that the same effect as that of the invention of any one of claims 20 to 22 can be obtained, the first lens and / or the second lens. By changing the magnification, it is possible to select an appropriate aperture diameter for the object to be measured.
Therefore, by changing the magnification of the lens, the aperture diameter of the aperture can be adjusted, and it is not necessary to prepare an aperture corresponding to the size of the object to be measured each time. It can be performed.

According to the invention described in claim 24, it is needless to say that the same effect as that of any one of the inventions described in claims 15-23 can be obtained, and the object to be measured is rotated at a predetermined angle by the rotating means. Each time the object to be measured is rotated at a predetermined angle by the rotating means, one cross-sectional shape of the object to be measured is calculated by the cross-sectional shape calculating means, and the whole surface of the object to be measured is calculated by the shape measuring means. The cross-sectional shape can be calculated.
Accordingly, the step of calculating the cross-sectional shape of the object to be measured and the step of rotating the object to be measured by a predetermined angle can be alternately repeated, and the cross-sectional shape of the entire surface of the object to be measured can be easily and efficiently performed. It can be measured well.

  According to the invention of claim 25, it is needless to say that the same effect as that of the invention of any one of claims 15 to 24 can be obtained, and the shape of a sphere can be measured easily and efficiently. It can be performed.

  Hereinafter, specific embodiments of the shape measuring method and 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, an aperture 20, a rotation mechanism 30 that rotates and supports an object to be measured 200, a magnifying lens 40, an imaging unit 50, The aperture 20, the measured object 200, the magnifying lens 40, and the imaging unit 50 are arranged in this order along the optical axis of the light emitted from the light source unit 10.

For example, as illustrated in FIG. 1, the light source unit 10 uses a point light source that outputs white light, and irradiates the measured object 200 with 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.
In addition, as shown in FIG. 2, the light source unit 10 can include a diffusion plate 12 as a scattering unit between a point light source and an aperture 20 described later, and from the point light source via the diffusion plate 12. The output white light can be scattered.
Further, as shown in FIG. 3, the light source unit 10 can include a collimating lens 13 as a parallel means between a point light source and an aperture 20 to be described later, and the point light source via the collimating lens 13. The output white light can be converted into parallel light.

For example, as shown in FIG. 4, the aperture 20 has a substantially rectangular flat plate shape. The aperture 20 has an opening 21 larger than the outer shape of the object 200 to be measured, and is arranged so that the center of the opening 21 and the optical axis of the light source unit 10 overlap. Further, the opening 21 is substantially similar to a cross-sectional shape of the object 200 to be measured.
More specifically, when the measured object 200 is a sphere having a diameter of 50 μm, the aperture 20 has a circular opening 21 having an inner diameter of about 52 μm to 55 μm, as shown in FIG.
Further, the thickness of the aperture 20 is a design matter, but it is desirable that the thickness of the aperture 20 be thinner in order to reduce light scattering on the inner wall surface of the opening 21 of the aperture 20.
Moreover, the cross-sectional shape of the inner wall part 21a which forms the opening 21 of the aperture 20 is a knife edge as shown in FIG. Thereby, scattering on the inner wall surface of light incident on the opening 21 from the light source unit 10 can be reduced, and light diffraction can be suppressed.

For example, as shown in FIG. 5, the rotation mechanism 30 includes a grip portion 31 and a spindle 32.
The grip portion 31 grips the shaft portion 201 formed integrally with the object to be measured 200. As a configuration for gripping the shaft portion 201, for example, a collet chuck is used. The center of the object to be measured 200 is formed on the extension line of the rotation axis of the shaft portion 201 formed integrally with the object to be measured 200.
The spindle 32 is connected to the grip portion 31 and rotates the object 200 to be measured, for example, with an axis that is perpendicular to the optical axis of the light source unit 10 as a rotation axis. The spindle 32 controls the rotation angle by using, for example, an encoder (not shown).
The rotation mechanism 30 is configured to be movable in the X-axis, Y-axis, and Z-axis directions with the gripping portion 31 gripping the object to be measured 200, so that the center of the object to be measured 200 is the opening of the aperture 20. 21 can be positioned at the center.
The rotation mechanism 30 functions as a rotation unit by including the grip portion 31 and the spindle 32.

  For example, as shown in FIG. 1, the magnifying lens 40 is disposed between the aperture 20 and the measured object 200 and the imaging surface of the imaging unit 50 described later on the optical axis of the light emitted from the light source unit 10. Has been.

The imaging unit 50 uses, for example, a CCD camera as imaging means, and images a mapping through the magnifying lens 40.
Specifically, as illustrated in FIG. 6, a light ring formed by the light output from the light source unit 10 irradiating the object to be measured through the aperture 20 is imaged through the magnifying lens 40.
The 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 image processing unit 60 includes a CPU 61, a cross-sectional shape calculation program 62, a shape measurement program 63, and a display unit 64 that displays an image processing result.
The image processing unit 60 performs processing of the mapping imaged by the imaging unit 50, and the CPU 61 executes a cross-sectional shape calculation program 62, so that one cross section of the measured object 200 is obtained from the light intensity distribution of the image processed mapping. Calculate the shape.
Specifically, the cross-sectional shape of the sphere that is the object to be measured is obtained by, for example, collecting a light intensity pattern of a mapping imaged by the imaging unit 50 on an orthogonal coordinate axis to determine a temporary center, and setting the center as the origin The edge of the sphere and the edge of the aperture 20 are detected by detecting the edge of the bright spot in the predetermined azimuth angle direction, and calculation is performed by comparison with the aperture 20.

  More specifically, for example, as shown in FIG. 14, the grayscale image of the mapping imaged by the imaging unit 50 is binarized, and the inner circle boundary and the outer circle boundary are detected. Then, the center of the least square circle is calculated from the position of the boundary of the inner circle (a set of pixel positions on the image), and this center is set as the temporary center of one section of the sphere. Similarly, the temporary center of the aperture 20 is calculated from the boundary of the outer circle.

  Next, for example, as shown in FIG. 15, in the original grayscale image, the edge of the sphere and the aperture 20 are obtained by using a differential method or the like for each predetermined angle from each temporary center of the sphere and the aperture 20. Detect edges of FIG. 15 is a diagram illustrating a process of deriving an edge of one cross section of the sphere in the direction of the predetermined angle θ, that is, the radius R (θ) and an edge of the aperture 20 in the direction of the predetermined angle θ ′, that is, the radius R ′ (θ ′). .

  Next, from the edge of the detected sphere and the edge of the aperture 20, the sphere one cross-sectional shape and the center of the least square circle of the aperture 20 are calculated, and again by using a differential method or the like for each predetermined angle from this center, The edge of the sphere and the edge of the aperture 20 are detected.

  Next, the shape calculated from the edge of the aperture 20 is corrected by comparing the shape calculated from the detected edge of the aperture 20 and the shape of the opening 21 of the aperture 20, and accompanying the correction. Based on the correction amount, the cross-sectional shape of the sphere is calculated by correcting the shape of the detected edge of the sphere. Further, based on the calculated one cross-sectional shape, the roundness in one cross section of the sphere is calculated.

  The CPU 61 functions as a cross-sectional shape calculating unit by executing the cross-sectional shape calculating program 62.

Further, each time the sphere that is the object 200 to be measured is rotated by a predetermined angle by the rotation mechanism 30, one cross-sectional shape of the sphere at each rotation angle is calculated, and the CPU 61 executes the shape measurement program 63. The cross-sectional shape on the entire circumference of the sphere is calculated.
Specifically, as described above, the shape calculated from the edge of the aperture 20 and the shape of the opening 21 of the aperture 20 are compared and the shape calculated from the edge of the aperture 20 is corrected. The cross-sectional shape of the sphere is calculated by correcting the shape of the edge of the detected sphere based on the correction amount associated with, and the perfect circle on one cross-section of the sphere is calculated based on the calculated one cross-sectional shape. Calculate the degree.
Then, the above-described roundness calculation is obtained at a predetermined rotation angle on the entire circumferential surface of the sphere, and the sphericity of the sphere is calculated based on the variation in the roundness value.

  The CPU 61 functions as a shape measuring unit by executing the shape measuring program 63.

  Next, a method for measuring the shape of the measured object 200 using the shape measuring apparatus 100 according to the first embodiment will be described.

First, as shown in FIG. 1, the optical axis and the plane of the aperture 20 are arranged so as to intersect perpendicularly, and the center of the opening 21 of the aperture 20 and the center of the measured object 200 are on the optical axis. The aperture 20 and the measured object 200 are arranged so as to overlap.
At this time, it is desirable to arrange the aperture 20 and the measured object 200 in the vicinity.

  Next, as shown in FIG. 3, a collimator lens 13 that converts light emitted from the light source unit 10 into parallel light is disposed on the optical axis between the light source unit 10 and the aperture 20.

  Next, a magnifying lens 40 for enlarging the mapping is inserted between the aperture 20 and the measured object 200 and the imaging unit 50 on the optical axis of the light emitted from the light source unit 10.

  Next, a step of calculating one cross-sectional shape of the sphere from the light intensity distribution of the map imaged by the imaging unit 50 and, for example, an axis that is perpendicular to the optical axis of the light source unit 10 by the rotation mechanism 30. The step of rotating at a predetermined angle as the rotation axis is repeated to calculate the cross-sectional shape on the entire circumferential surface of the sphere.

As described above, the collimator lens 13 is disposed between the light source unit 10 and the aperture 20 so that the light emitted from the light source unit 10 is output in parallel, and the measured object 200 is irradiated with the light. When the object to be measured 200 is irradiated with light, the diffraction of the light can be conspicuous through the aperture 20 having an opening larger than the outer shape of the object to be measured 200. A map formed by irradiating the object 200 to be measured, which is irradiated with light emitted from the light source unit 10, can be captured, and the CPU 61 executes the cross-sectional shape calculation program 62 to capture the captured map. The cross-sectional shape of the object 200 to be measured can be calculated from the light intensity distribution.
Therefore, since the light emitted from the light source can be condensed as parallel light, the entire diffraction pattern becomes brighter, the contrast becomes stronger, the diffraction spread angle is smaller than that of a point light source, and an easy-to-handle diffraction pattern is obtained. As a result, the shape of the object to be measured can be measured easily and efficiently.
Further, the object to be measured 200 can be rotated at a predetermined angle by the rotation mechanism 30, and the CPU 61 executes the cross-sectional shape calculation program 62 every time the object to be measured 200 is rotated at a predetermined angle by the rotation mechanism 30. Thus, one cross-sectional shape of the measured object 200 is calculated, and the CPU 61 executes the shape measurement program 63, whereby the cross-sectional shape of the entire measured object 200 can be calculated.
Accordingly, the step of calculating the cross-sectional shape of the object to be measured and the step of rotating the object to be measured by a predetermined angle can be alternately repeated, and the cross-sectional shape of the entire surface of the object to be measured can be easily and efficiently performed. It can be measured well.
Further, since the magnifying lens 40 for enlarging the mapping is provided between the aperture 20 and the measured object 200 and the imaging surface of the imaging unit 50, the shape can be easily and efficiently formed even when the measured object 200 is very small. Measurements can be made.

(Second Embodiment)
Next, 2nd Embodiment which concerns on the shape measuring apparatus of this invention is described with reference to FIG. The basic configuration of the second embodiment is the same as that of the first embodiment, except that the magnifying lens 40 in the first embodiment is replaced with a telecentric lens 45.
According to such a configuration, the telecentric lens 45 can target only the light parallel to the optical axis out of the light that has passed through the aperture 21 of the aperture 20, and the error in the size of the mapping can be reduced. As a result, it is possible to perform more suitable shape measurement.
Further, the shape measuring method of the measured object 200 in the shape measuring apparatus 300 in the second embodiment is the same as that in the first embodiment.

(Third embodiment)
As shown in FIG. 8, the shape measuring apparatus 1100 according to the third embodiment includes a light source unit 1010, an aperture 20, a rotation mechanism 30, an objective lens 1040 as a first lens, and an objective as a second lens. A lens 1050, an imaging unit 1060, and an image processing unit 60 are provided, and the object to be measured 200, the objective lens 1040, the aperture 20, and the objective are sequentially arranged along the optical axis of the light emitted from the light source unit 1010. A lens 1050 and an imaging unit 1060 are disposed. In addition, the same code | symbol is attached | subjected to the same part as 1st and 2nd embodiment, and only a different part is demonstrated.

  For example, as illustrated in FIG. 8, the light source unit 1010 irradiates the measurement object 200 with white light using a point light source that outputs white light. The light source unit is not limited to such a point light source, and may be a surface light source, or may generate light by a discharge lamp, a light emitting diode, a laser, or the like.

For example, as shown in FIG. 8, the objective lens 1040 is arranged between the measured object 200 and the aperture 20 on the optical axis of the light emitted from the light source unit 1010, and maps the measured object 200. Expanding.
Further, for example, as shown in FIG. 8, the objective lens 1050 is disposed between the aperture 20 and the imaging unit 1060 on the optical axis of the light emitted from the light source unit 1010, and the mapping of the aperture 20, and The map of the measured object 200 magnified by the objective lens 1040 is magnified.

For example, a CCD camera is used as the imaging unit, and the imaging unit 1060 captures a map through the objective lens 1050.
Specifically, for example, as shown in FIG. 9, the light irradiated from the light source unit 1010 irradiates the object 200 to be measured, and a ring of light generated through the aperture 20 is imaged through the objective lens 1050.
The image capturing unit 1060 functions as an image capturing unit by capturing a map using such a CCD camera.

  Next, a method for measuring the shape of the measured object 200 by the shape measuring apparatus 1100 according to the third embodiment will be described.

  First, as shown in FIG. 8, the object to be measured 200, the objective lens 1040, the aperture 20, and the objective lens 1050 are arranged on the optical axis between the light source unit 1010 and the imaging surface of the imaging unit 1060 from the light source unit 1010 side. Arranged in this order. At this time, the diameter of the opening 21 of the aperture 20 is determined by the magnification at which the measured object 200 is enlarged by the objective lens 1040. The aperture 20 is arranged at a position where the image of the object 200 to be measured is imaged after passing through the objective lens 1040.

  Next, the light emitted from the light source unit 1010 passes through the aperture 21 of the aperture 20 through the objective lens 1040, and further passes through the objective lens 1050 to obtain a spherical shape from the light intensity distribution of the image captured by the imaging unit 1060. A step of calculating one cross-sectional shape and a step of rotating the object 200 to be measured at a predetermined angle with an axis that is perpendicular to the optical axis of the light source unit 1010 as a rotation axis are repeated by the rotation mechanism 30, for example. The cross-sectional shape on the entire circumference of the sphere that is the measurement object 200 is calculated.

Thus, according to the shape measuring apparatus 1100 in the third embodiment, the light source unit 1010 can irradiate the object under measurement 200, and the objective lens 1040 and the objective lens 1050 irradiate the light source unit 1010. The object 200 to be measured can be passed through the aperture 20 having an opening larger than the outer shape of the object 200 when the object 200 is irradiated with light. The imaging unit 1060 can capture a map emitted from the objective lens 1050, and the CPU 61 executes the cross-sectional shape calculation program 62 so that the image is captured by the imaging unit 1060. The shape of the measured object 200 can be calculated from the light intensity distribution of the mapping.
Therefore, the edge of the object to be measured can be detected from the light intensity distribution of the picked-up light ring, and the shape of the object to be measured can be measured easily and efficiently. Further, measurement can be performed without depending on the distance between the measured object and the aperture, and physical interference between the measured object and the aperture can be suitably prevented. In addition, the size of the image of the object to be measured is determined by the magnification of the objective lens 1040, and the degree of freedom of the aperture diameter of the aperture can be increased accordingly.
Further, the object to be measured 200 can be rotated at a predetermined angle by the rotation mechanism 30, and the CPU 61 executes the cross-sectional shape calculation program 62 every time the object to be measured 200 is rotated at a predetermined angle by the rotation mechanism 30. Thus, one cross-sectional shape of the object to be measured 200 is calculated, and the CPU 61 executes the shape measurement program 63, whereby the cross-sectional shape of the entire surface of the object to be measured 200 can be calculated.
Therefore, the process of calculating the cross-sectional shape of the object to be measured and the process of rotating the object to be measured by a predetermined angle can be repeated, and the cross-sectional shape of the entire surface of the object to be measured can be measured easily and efficiently. can do.

(Fourth embodiment)
Next, a fourth embodiment according to the shape measuring apparatus of the present invention will be described with reference to FIG. The basic configuration of the fourth embodiment is the same as that of the third embodiment, except that the first lens is a telecentric lens 1045.
According to such a configuration, by using the telecentric lens, the position of the diaphragm is arranged at the focal position of the lens, and by reducing the aperture, a lot of light from the object to be measured is blocked by the diaphragm, and the image is captured. The light to be formed is only light that has entered the lens from the object to be measured and is approximately parallel to the optical axis, then passed through the aperture through the focal point, and only the substantially parallel light from the object to be measured is involved in image formation. Small variation in magnification due to change in object position.
Therefore, it is possible to suppress a change in magnification due to a displacement of the object to be measured, and it is possible to suppress a change in size due to a displacement caused by a movement error when the object to be measured is rotated by the rotation mechanism. . In addition, light diffraction can be relaxed, and a more suitable shape measurement can be performed.
Further, the shape measuring method of the measured object 200 in the shape measuring apparatus 1200 in the fourth embodiment is the same as that in the third embodiment.

(Fifth embodiment)
Next, a fifth embodiment according to the shape measuring apparatus of the present invention will be described with reference to FIG. The basic configuration of the fifth embodiment is the same as that of the third embodiment, but the second lens is a telecentric lens 1055.
According to such a configuration, the telecentric lens 1055 can irradiate the object 200 to be measured, and light diffraction generated through the aperture 20 can be relaxed, so that more suitable shape measurement can be performed.
Moreover, the shape measuring method of the measured object 200 in the shape measuring apparatus 1300 in the fifth embodiment is the same as that in the third embodiment.

(Sixth embodiment)
Next, a sixth embodiment according to the shape measuring apparatus of the present invention will be described with reference to FIG. The basic configuration of the sixth embodiment is the same as that of the third embodiment, except that the first lens and the second lens are telecentric lenses 1045 and 1055, respectively.
According to such a configuration, the telecentric lenses 1045 and 1055 can suppress the change in magnification due to the displacement of the object to be measured as in the fourth embodiment, and the object to be measured can be moved by the rotation mechanism. When rotated, the change in size due to the displacement caused by the motion error can be suppressed, and similarly to the fifth embodiment, the object to be measured is irradiated and the diffraction of light generated through the aperture is alleviated. Therefore, more suitable shape measurement can be performed.
In addition, the shape measuring method of the measured object 200 in the shape measuring apparatus 1400 in the sixth embodiment is the same as that in the third embodiment.

(Seventh embodiment)
Next, a seventh embodiment according to the shape measuring apparatus of the present invention will be described with reference to FIG. As shown in FIG. 13, the basic configuration of the seventh embodiment includes a light source unit 1010, an aperture 20, a rotation mechanism 30, an objective lens 1040 as a first lens, and an objective lens as a second lens. 1050, an imaging unit 1060, and an image processing unit 60, and in order along the optical axis of the light emitted from the light source unit 1010, the aperture 20, the objective lens 1040, the measured object 200, and the objective lens 1050 and an imaging unit 1060 are arranged.
According to such a configuration, the edge of the object to be measured can be detected from the light intensity distribution of the imaged light ring, and the shape of the object to be measured can be measured easily and efficiently. Further, measurement can be performed without depending on the distance between the measured object and the aperture, and physical interference between the measured object and the aperture can be suitably prevented. Further, the size of the image of the object to be measured can be set by the magnification of the second lens, and the degree of freedom of the aperture diameter of the aperture can be increased accordingly.
Furthermore, by disposing the aperture 20 on the light source unit 1010 side with respect to the measured object 200, it is possible to prevent light from being scattered when the light output from the light source unit 1010 is irradiated onto the measured object. Thus, the utilization efficiency of light emitted from the light source unit 1010 can be increased.
Further, the shape measuring method of the object 200 to be measured in the shape measuring apparatus 1500 in the seventh embodiment is the same as that in the third embodiment.

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.
Moreover, the design which feeds back the measured value which calculated one cross-sectional shape of the to-be-measured object to the processing machine of a to-be-measured object may be sufficient. Thereby, the processing of the object to be measured and the shape measurement of the object to be measured can be performed efficiently.
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 in 1st Embodiment which concerns on this invention. It is the schematic which shows the structure which used the diffusion plate about the shape measuring apparatus which concerns on this invention. It is the schematic which shows the structure using the collimator lens about the shape measuring apparatus which concerns on this invention. It is the front view and sectional drawing which show the aperture which concerns on this invention. It is the schematic which shows the state which attached the to-be-measured object to the rotation mechanism which concerns on this invention. It is a figure which shows the state by which light was irradiated to the to-be-measured object via the aperture when light was irradiated from the light source part in 1st Embodiment which concerns on this invention. It is the schematic which shows the structure of the shape measuring apparatus in 2nd Embodiment which concerns on this invention. It is the schematic which shows the structure of the shape measuring apparatus in 3rd Embodiment which concerns on this invention. When light is irradiated from the light source part in 3rd Embodiment which concerns on this invention, light is irradiated to a to-be-measured object and it is a figure which shows the state of the light seen through an aperture. It is the schematic which shows the structure of the shape measuring apparatus in 4th Embodiment which concerns on this invention. It is the schematic which shows the structure of the shape measuring apparatus in 5th Embodiment concerning this invention. It is the schematic which shows the structure of the shape measuring apparatus in 6th Embodiment which concerns on this invention. It is the schematic which shows the structure of the shape measuring apparatus in 7th Embodiment concerning this invention. It is a figure which shows the light intensity pattern of the map imaged by the imaging part which concerns on this invention. Based on the light intensity pattern of the map imaged by the imaging unit according to the present invention, the edge of one sphere in the predetermined angle θ direction, that is, the radius R (θ), and the edge of the aperture in the predetermined angle θ ′ direction, that is, the radius R ′ (θ ′) ) Is a diagram showing a process of deriving.

Explanation of symbols

10 Light Source 12 Diffuser (scattering means)
13 Collimating lens (parallel means)
20 Aperture 30 Rotating mechanism (Rotating means)
40 Magnifying lens 45 Telecentric lens 50 Imaging unit (imaging means)
60 Image processing unit 61 CPU (cross-sectional shape calculating means, shape measuring means)
62 Cross-sectional shape calculation program (cross-sectional shape calculation means)
63 Shape measurement program (shape measurement means)
100 shape measuring apparatus (first embodiment)
200 Object to be measured 300 Shape measuring device (second embodiment)
1010 Light source unit 1040 Objective lens (first lens)
1045 Telecentric lens (first lens)
1050 Objective lens (second lens)
1055 Telecentric lens (second lens)
1060 Imaging unit (imaging means)
1100 Shape Measuring Device (Third Embodiment)
1200 shape measuring device (fourth embodiment)
1300 Shape Measuring Device (Fifth Embodiment)
1400 Shape Measuring Device (Sixth Embodiment)
1500 shape measuring device (seventh embodiment)

Claims (25)

In the shape measuring method for measuring the shape of the object to be measured which is a rotationally symmetric body,
Arranging an aperture having an opening larger than the outer shape of the object to be measured on the optical axis and the object to be measured;
Imaging a map formed by irradiating the object to be measured with light by imaging means;
Calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
A shape measuring method comprising:   The shape measuring method according to claim 1, wherein a magnifying lens for magnifying the mapping is disposed between the aperture and the object to be measured and an imaging surface of the imaging unit to capture the mapping. The shape measuring method according to claim 1, wherein a telecentric lens is disposed between the aperture and the object to be measured and an imaging surface of the imaging unit to capture the mapping.   The shape measuring method according to claim 1, wherein the light is scattered light.   The shape measuring method according to claim 1, wherein the light is parallel light. In the shape measuring method for measuring the shape of the object to be measured which is a rotationally symmetric body,
From the light source unit side on the optical axis between the light source unit and the imaging surface of the imaging unit, from the outer shape of the measured object to the image forming position of the measured object, the first lens, and the first lens An aperture having a larger aperture, and a step of arranging the second lens in that order;
Imaging the map formed by irradiating the object to be measured with light from the light source unit with the imaging means;
Calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
A shape measuring method comprising: In the shape measuring method for measuring the shape of the object to be measured which is a rotationally symmetric body,
An aperture, a first lens, and an image of the first lens having an opening larger than the outer shape of the object to be measured on the optical axis from the light source unit side between the light source unit and the imaging surface of the imaging unit. Arranging the object to be measured and the second lens in order at a position;
Imaging the map formed by irradiating the object to be measured with light from the light source unit with the imaging means;
Calculating a cross-sectional shape of the object to be measured from a light intensity distribution of a map imaged by the imaging means;
A shape measuring method comprising:   The shape measuring method according to claim 6, wherein the first lens and / or the second lens is a telecentric lens unit.   The aperture diameter of an appropriate aperture for the object to be measured is selected by changing the magnification of the first lens and / or the second lens. The shape measuring method according to item. Rotating the object to be measured by a predetermined angle;
Alternately calculating a cross-sectional shape of the object to be measured and a step of rotating the object to be measured at a predetermined angle to calculate a cross-sectional shape of the entire surface of the object to be measured;
The shape measuring method according to any one of claims 1 to 9, further comprising:   The shape measurement method according to claim 1, wherein the object to be measured is a sphere. The step of calculating one cross-sectional shape of the sphere includes:
By collecting the light intensity pattern of the map imaged by the imaging means on an orthogonal coordinate axis to determine a temporary center, and detecting the edge of the bright spot in a predetermined azimuth direction with the center as the origin, the sphere Edge and the edge of the aperture,
By comparing the shape calculated from the detected edge of the aperture with the predetermined aperture shape of the aperture, the shape calculated from the edge of the aperture is corrected, and based on the correction amount accompanying the correction, The shape measuring method according to claim 11, wherein the cross-sectional shape of the sphere is calculated by correcting the shape of the detected edge of the sphere. 13. The shape measuring method according to claim 12, wherein the roundness in one section of the sphere is calculated based on the calculated one section shape of the sphere.   The roundness of the sphere is calculated based on a variation in the roundness value by obtaining the roundness at a predetermined rotation angle on the entire circumferential surface of the sphere. Shape measurement method. In a shape measuring device that measures the shape of a measured object that is a rotationally symmetric body,
A light source unit for irradiating the object to be measured with light;
An aperture disposed on the optical axis of light output from the light source unit and having an opening larger than the outer shape of the object to be measured;
Imaging means for imaging a map formed by irradiating the object to be measured disposed on the optical axis with 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;
A shape measuring apparatus comprising:   16. The shape measuring apparatus according to claim 15, further comprising a magnifying lens for enlarging the mapping between the aperture and the object to be measured, and an imaging surface of the imaging means. The shape measuring apparatus according to claim 15, further comprising a telecentric lens between the aperture and the object to be measured, and an imaging surface of the imaging unit.   The shape measuring apparatus according to claim 15, wherein the light source unit includes a scattering unit that scatters and outputs light.   The shape measuring apparatus according to claim 15, wherein the light source unit includes parallel means for outputting light in parallel. In a shape measuring device that measures the shape of a measured object that is a rotationally symmetric body,
A light source unit for irradiating the object to be measured with light;
First and second lenses that pass a map of the object to be measured by the light emitted by the light source unit;
An aperture disposed at an imaging position of the first lens between the first lens and the second lens and having an opening larger than an outer shape of the object to be measured;
Imaging means for imaging a map emitted from the second lens;
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;
A shape measuring apparatus comprising: In a shape measuring device that measures the shape of a measured object that is a rotationally symmetric body,
A light source unit for irradiating the object to be measured with light;
An aperture having an opening larger than the outer shape of the object to be measured, and an aperture through which the light irradiated by the light source unit passes through the opening;
First and second lenses for passing light that has passed through the aperture;
The second lens is disposed on the opposite side of the first lens, and is disposed at an imaging position of the first lens between the first lens and the second lens. An imaging means for imaging a map of the measured object;
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;
A shape measuring apparatus comprising:   The shape measuring apparatus according to claim 20 or 21, wherein the first lens and / or the second lens is a telecentric lens unit. 21. A configuration in which an aperture diameter of an appropriate aperture with respect to the object to be measured can be selected by changing a magnification of the first lens and / or the second lens. The shape measuring apparatus according to any one of 22. Rotating means for rotating the object to be measured at a predetermined angle;
A shape that calculates one cross-sectional shape of the object to be measured by the cross-sectional shape calculating means each time the object to be measured is rotated by a predetermined angle by the rotating means, and calculates a cross-sectional shape on the entire circumference of the object to be measured. Measuring means;
The shape measuring device according to any one of claims 15 to 23, comprising:   The shape measuring apparatus according to claim 15, wherein the object to be measured is a sphere.

Images