JP2004150929A - Three-dimensional measuring instrument and three-dimensional measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow three-dimensional measurement of high measuring precision for a pin-shaped upper end face, in the three-dimensional measurement for a measuring object having a pin-shaped protrusion. <P>SOLUTION: This three-dimensional measuring instrument is provided with a grating 30 wherein slits extended Y-axis-directionally are arrayed on an X-Y plane at a fixed pitch, a grating position control part 4 for moving the grating 30, the first linear irradiation system 1a and the second linear irradiation system 1b for emitting linear parallel beams extended Y-axis-directionally along a Y-axis, a photoreceiving part 2 for reading a plurality of Moire fringe images of the measuring object 50 via the grating 30, and a control system for controlling an operation of the grating position control part 4, for calculating a representative measured value based on a plurality of Moire fringe image data read into the photoreceiving part 2, and for converting it into three-dimensional data. The high measuring precision is provided by using a three-dimensional measurement result in an edge portion of a tip part of the protrusion 51 as the three-dimensional measurement result of the upper end face. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a three-dimensional measuring device and a three-dimensional measuring method for measuring a surface of an object to be measured.
[0002]
[Prior art]
As a non-contact three-dimensional measuring device for general industrial parts and the like, an optical cutting method that can obtain a measurement result with low cost and high accuracy is most frequently used. However, since the light sectioning method performs two-dimensional scanning, the imaging time becomes long. Therefore, it is not suitable for measurement in which it is difficult to fix an object to be measured such as a living body. Further, since the light-section method uses a laser beam that is harmful to the eyes, there is a problem in using it on the face of a living body, which is a main measurement site in the beauty field. Therefore, moire topography, which can perform high-speed and high-accuracy measurement using a white light source that is harmless to a living body, has attracted attention. Moire topography is a non-contact three-dimensional measurement method for obtaining a contour image of a target object using moiré fringes.
[0003]
Moire topography as a three-dimensional measurement technique is used in fields such as engineering, medicine, dentistry, and fashion. There are roughly two methods for shape measurement by moire topography. A method in which a grid is placed just before the object to be measured and moire fringes are generated by the shadow of the grid and the grid just before (grid irradiation type), and the moiré grid is projected on the object to be measured and changes depending on the shape of the object to be measured Is a method of forming moire fringes by forming an image of the formed grating on a grating having the same pitch by an imaging lens (grating projection type). The grating irradiation type is applied to measurement from about several tens of μm to irregularities of several cm. The grid projection type is applied when measuring an object to be measured having relatively large irregularities (several mm to several cm).
[0004]
Conventional three-dimensional measurement solves the problem of phase concatenation when deriving a phase in the measurement by the phase shift method using an arctangent function. (For example, refer to Patent Document 1). In addition, the reflection from the grating that forms the moiré fringes is measured by adjusting the angle of the grating and rotating the deflector so that the reflected light from the object to be measured and the reflected diffraction light from the substrate are distinguished. (See, for example, Patent Document 2).
[0005]
[Patent Document 1]
JP 2001-124534 A
[0006]
[Patent Document 2]
JP-A-7-332956
[0007]
[Problems to be solved by the invention]
For example, consider measuring the height of the pins of a pin grid array (PGA). The upper end surface of the pin shape of the PGA is generally subjected to rough processing such as cutting, or the upper end surface is generally a surface having irregularities because no surface treatment is performed. When performing three-dimensional measurement of an object to be measured having such a PGA pin shape by moire topography, the surface state (surface morphology) of the upper end surface is not uniform, and the surface has random irregularities. I cannot measure accurately.
[0008]
Further, the pin-shaped tip of the object to be measured may be bent (inclined), and the bent tip may not be measured.
[0009]
In view of the above problems, the present invention provides a three-dimensional measuring device and a three-dimensional measuring method capable of performing measurement with high measurement accuracy even on an object to be measured in which the surface state (surface morphology) of the upper end surface of the pin is not uniform. Aim.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a first feature of the present invention is that (a) a lattice in which slits extending in the Y-axis direction are arranged at a constant pitch on an XY plane and (b) a lattice plane is substantially formed. A grid position control unit that keeps the grid parallel to the XY plane and moves the grid with respect to the object to be measured in the Z-axis direction orthogonal to the XY plane; A linear irradiation system that emits parallel light, (2) a light receiving unit that captures an image of a moire fringe of an object to be measured via a grating, and (e) three-dimensional measurement of image data of the moiré fringe captured by the light receiving unit. The gist is to provide a three-dimensional measurement device including an image processing unit that converts the data into data. Here, the XY plane is an XY plane in an XYZ coordinate system orthogonal to each other, and the Z axis is a Z axis in the XYZ coordinate system.
[0011]
For example, consider moire measurement in the case where the surface of the upper end surface of a columnar projection has irregularities. The edge of the tip of the cylinder always gives an arc-shaped topology defined by the boundary between the top surface and the side surface of the cylinder, even when the top surface has random irregularities. According to the three-dimensional measurement device according to the first aspect of the present invention, the linear parallel light along the longitudinal direction (Y-axis) of the slit of the grating is incident on the grating, so that the tip of the measured object is formed. It is possible to obtain moiré fringes from the edge of. That is, since moire fringes from the edge of the tip of the protrusion can be measured, even when the surface of the upper end surface of the protrusion has random irregularities, it is possible to always obtain a constant moire fringe. . That is, even when the projections have unexpected irregularities on the surface of the upper end surface, three-dimensional measurement can be performed without being affected by the morphology unevenness of the upper end surface.
[0012]
Furthermore, in the three-dimensional measuring apparatus according to the first aspect of the present invention, the first and second linear irradiation systems are provided, and the edges of the tips of the projections are measured at two locations facing each other, and two locations are measured. If the average value is used as a representative measurement value of the tip position, three-dimensional measurement of the pin-shaped upper end surface with high measurement accuracy can be performed. That is, by using the first and second linear irradiation systems and irradiating two lights from different directions, for example, even if the projection is inclined (bent) to the left or right, By using the average value of the image data from the edge located at the edge and the image data from the edge located at the upper side as the representative measurement value, it is possible to obtain an accurate measurement value. Instead of providing the first and second linear irradiation systems, equivalent irradiation is possible even if the object to be measured is rotated. Furthermore, even if a single linear irradiation system is moved, the grating can be irradiated with parallel light from different directions.
[0013]
The second feature of the present invention is that (a) the surface of a lattice in which slits extending in the Y-axis direction are arranged at a constant pitch on an XY plane is kept substantially parallel to the XY plane, and the object to be measured is Moving in the Z-axis direction perpendicular to the XY plane, (b) emitting linear parallel light along the Y-axis to the grid, and (c) moving the object to be measured via the grid. The gist is to provide a three-dimensional measurement method including a step of capturing an image of moire fringes and a step of (2) converting the image into three-dimensional measurement data.
[0014]
According to the three-dimensional measurement method according to the second aspect of the present invention, since the grid is irradiated with the linear parallel light along the longitudinal direction (Y axis) of the slit of the grid, the edge of the tip of the protrusion is formed. Can be measured. For this reason, even when the surface of the upper end surface of the projection has random irregularities, it is possible to always obtain a constant moire fringe. That is, even when the projections have unexpected irregularities on the surface of the upper end surface, three-dimensional measurement can be performed without being affected by the morphology unevenness of the upper end surface.
[0015]
Further, in the three-dimensional measuring method according to the second aspect of the present invention, if the edge of the tip of the projection is measured at two locations facing each other, and the average value of the two locations is set as a representative measurement value of the location of the tip, Highly accurate three-dimensional measurement of the upper end surface of the pin shape is possible. In other words, by using two lights from different directions, for example, even when the projection is inclined (bent) to the left or right, the image data from the edge located on the lower side and the image data located on the upper side By using the average value with the image data from the edge as the representative measurement value, an accurate measurement value can be obtained.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, first to third embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the relationship between the thickness and the plane dimension, the ratio of the thickness of each layer, and the like are different from actual ones. Therefore, specific thicknesses and dimensions should be determined in light of the following description. In addition, it is needless to say that dimensional relationships and ratios are different between drawings.
[0017]
(First Embodiment)
As shown in FIGS. 1 and 2, the three-dimensional measurement apparatus according to the first embodiment of the present invention includes a grid 30 and a grid position control for moving the grid 30 in a Z-axis direction orthogonal to the XY plane. Unit 4, a first linear irradiation system 1a and a second linear irradiation system 1b that emit parallel light to the grating 30, and a light receiving unit 2 that captures an image of a moire fringe of the measured object 50 via the grating 30; And a control system 43. The grating 30 has slits extending in the Y-axis direction arranged at a constant pitch p on the XY plane. The grid position controller 4 keeps the plane of the grid 30 substantially parallel to the XY plane, and moves the grid 30 in the Z-axis direction with respect to the measured object 50. The control system 43 controls the operation of the grid position control unit 4 and converts the image captured by the light receiving unit 31 into three-dimensional measurement data.
[0018]
The first linear irradiation system 1a includes a first light source 10a that is a linear light source extending in the Y-axis direction, and a first collimator that converts illumination light emitted from the first light source 10a into linear parallel light extending in the Y-axis direction. And a lens 11a. Similarly to the first linear irradiation system 1a, the second linear irradiation system 1b extends a second light source 10b which is a line light source extending in the Y-axis direction and illumination light emitted from the second light source 10b in the Y-axis direction. A second collimator lens 11b for converting the light into linear parallel light. The first light source 10a and the second light source 10b as “linear light sources” include, for example, a filter or a spectroscope for making a columnar light source extending in the Y-axis direction such as a fluorescent discharge tube, a low-pressure mercury lamp, a xenon lamp or the like a monochromatic light source. It can be used through. The first linear irradiation system 1a and the second linear irradiation system 1b irradiate linear parallel light from different directions with respect to the XY plane. As the first collimator lens 11a and the second collimator lens 11b, for example, a plano-convex cylindrical lens extending in the Y-axis direction may be used.
[0019]
The light receiving unit 2 includes an image of the grating 30 in which the linear parallel light emitted in the Y-axis direction and emitted from the first linear irradiation system 1a passes through the grating 30 and is reflected on the surface to be measured of the object 50 to be measured. And a light receiving lens 21 such as a telecentric lens for condensing an image of moire fringes formed by superimposing the image and an image sensor 20 for capturing an image of moire fringes.
[0020]
The lattice position control unit 4 includes a moving mechanism 41 and a driving unit (stage controller) 42 for driving the moving mechanism 41, and is supplied with a control signal or the like from a control system 43 to control the position movement. That is, the control system 43 supplies a control signal or the like to the drive unit 42 to control the operation of the moving mechanism 41. The moving mechanism 41 includes a Z-axis stage 45 that moves the position of the lattice 30 along the Z-axis.
[0021]
The three-dimensional measuring device shown in FIG. 1 is shown more specifically in FIG. The control system 43 includes an image processing unit 60 and a control device 61 connected to the image processing unit 60. A light source drive circuit 70 for adjusting the light intensity of the first light source 10a and the second light source 10b is connected to the first light source 10a and the second light source 10b, respectively. The drive unit 42 for driving these components is connected to the Z-axis stage 45. Although not shown, the movement position of the Z-axis stage 45 is measured by, for example, a laser interferometer or the like, and is fed back to the control device 61. Alternatively, the position may be controlled by measuring the inductance accompanying the position change and performing electromagnetic control. The image sensor 20 shown in FIG. 1 is built in a camera 20a that captures an image of moire fringes in FIG. The measured object 50 is placed on a moving means 80 such as a belt conveyor that moves in parallel.
[0022]
The image processing unit 60 is a microprocessor or a personal computer whose output side is connected to the control board 62 and whose input side is connected to the image capturing board 63, respectively. As shown in FIG. 4, the image processing unit 60 averages the average values of the image data from two edges on the left and right sides of the upper end surface of the projection 51 and sets the average value as the representative measured value of the tip position of the projection 51. That is, the average of the image data obtained from the moiré images obtained from the two right and left edges of the upper end surface of the projection 51 due to the parallel light from the first linear irradiation system 1a and the second linear irradiation system 1b. The value is set as a representative measured value of the tip position of the protrusion 51. Then, the image processing unit 60 converts the representative measurement value into three-dimensional measurement data of the upper end surface of the pin-shaped projection 51. As described above, according to the three-dimensional measuring apparatus according to the first embodiment of the present invention, two opposing edges of the upper end surface of the projection 51 are measured, and the average value of the two points is represented as a representative of the tip position. By using the measured values, when measuring a three-dimensional object to be measured having a pin-shaped protrusion, the three-dimensional surface of the pin-shaped top surface having high measurement accuracy even with a curved protrusion having irregularities on the upper end surface. Can measure.
[0023]
The control device 61 includes a control board 62 connected to the image processing unit 60 on the input side, a control board 62 connected to the light source driving circuit 70, the driving unit 42, the camera 20a and the moving unit 80 on the output side, a camera 20a on the input side, and an image processing unit on the output side. And an image capturing board 63 connected to the unit 60.
[0024]
Hereinafter, the three-dimensional measurement method according to the first embodiment of the present invention will be described with reference to the flowchart of FIG.
[0025]
(A) First, in step S101, the grid 30 and the measured object 50 used for three-dimensional measurement are prepared, and the measured object 50 is mounted on the moving means 80. Here, the control signal CS is output from the image processing unit 60 and input to the control board 62 in the control device 61.
[0026]
(B) Next, in step S102, the luminance signal LC is output from the control board 62 and input to the light source drive circuit 70. The luminance signal LC is a signal for adjusting the light intensity of light emitted from the first light source 10a and the second light source 10b. The light intensity emitted from the first light source 10a and the second light source 10b is adjusted by the luminance signal LC in consideration of obtaining the same level of reflected light from the two opposing edge portions of the protrusion 51.
[0027]
(C) Next, in step S103, a measurement environment for performing three-dimensional measurement is set in the image processing unit 60. The processing in the image processing unit 60 is performed to capture and average the moire fringe images from two opposing edge portions at the same measurement position so that measurement errors are unlikely to occur, and to correct the inclination of the measurement surface. Setting of an arbitrary area of.
[0028]
(D) Next, in step S104, the shift signal SS is output from the control board 62 and input to the moving means 80. The measured object 50 placed on the moving means 80 is arranged at a desired position by the input shift signal SS. Then, the stage control signal PS is output from the control board 62 and input to the drive unit 42. The drive unit 42 to which the stage control signal PS has been input can control and drive the Z-axis stage 45. Therefore, the light from the first light source 10a and the second light source 10b is moved by moving the grating 30 so that the upper end surface of the projection 51 has measurement points at two opposing edges as shown in FIG. Is set to be able to be irradiated.
[0029]
(E) Next, in step S105, irradiation light is emitted from the first light source 10a and enters the first collimator lens 11a. The light incident on the first collimator lens 11a becomes linear parallel light extending in the Y-axis direction, and is incident on the grating 30. The moire fringes of the projections 51 are formed by the parallel light that is not blocked by the light-shielding portion of the grating 30 among the linear parallel light applied to the grating 30.
[0030]
(F) Next, in step S106, the shutter signal FC is output from the control board 62 and input to the camera 20a. When the shutter signal FC is input to the camera 20a, the shutter of the camera 20a is opened, and a plurality of moire fringe images generated by the measurement points at the left edge of the upper end surface of the projection 51 condensed by the light receiving lens 21 are captured.
[0031]
(G) Next, in step S107, the image of the moire fringes from the left edge is output from the camera 20a as an image analog signal GA (L) and input to the image capturing board 63. The image analog signal GA (L) is converted into a digital signal by the image capturing board 63, output as an image digital signal GD (L), and input to the image processing unit 60. The input image digital signal GD (L) is stored in an auxiliary storage device in the image processing unit 60. Furthermore, it is determined whether there is a measurement point on the measured object 50, and if so, the process returns to step S104.
[0032]
(H) Returning to step S105 again, the irradiation light is emitted from the second light source 10b and enters the second collimator lens 11b. The light incident on the second collimator lens 11b becomes linear parallel light extending in the Y-axis direction, and is incident on the grating 30. The moire fringes of the projections 51 are formed by the parallel light that is not blocked by the light-shielding portion of the grating 30 among the linear parallel light applied to the grating 30.
[0033]
(I) Next, in step S106, the shutter signal FC is output from the control board 62 and input to the camera 20a. When the shutter signal FC is input to the camera 20a, the shutter of the camera 20a is opened, and a plurality of moire fringe images generated by the measurement points at the right edge of the upper end surface of the projection 51 condensed by the light receiving lens 21 are captured.
[0034]
(G) Next, in step S107, the image of the moire fringe from the right edge is output from the camera 20a as an image analog signal GA (R) and input to the image capturing board 63. The image analog signal GA (R) is converted into a digital signal by the image capturing board 63, output as an image digital signal GD (R), and input to the image processing unit 60. The input image digital signal GD (R) is stored in an auxiliary storage device in the image processing unit 60. Further, it is determined whether or not the measured object 50 has a measurement point. In the case of two-point measurement of the left edge and the right edge, since there is no further measurement point, the process proceeds to step S108.
[0035]
(R) Next, in step S108, the image digital signal GD (L) from the left edge and the image digital signal GD (R) from the right edge are subjected to average processing by the image processing unit 60, and the representative measured value is obtained. Is calculated. The calculated representative measurement value is treated as a measurement result of the tip position of the protrusion 51. Then, the image processing unit 60 calculates three-dimensional measurement data of the measured object 50 based on the representative measurement value.
[0036]
(ヲ) Finally, in step S109, the three-dimensional measurement data obtained in step S108 is stored in the auxiliary storage device of the image processing unit 60.
[0037]
Even if the upper end surface of the projection 51 has irregularities, the edge of the tip of the cylinder always has an arc-shaped topology as shown in FIG. According to the three-dimensional measuring apparatus and the three-dimensional measuring method according to the first embodiment of the present invention, since the moire fringe from the edge of the tip of the projection is measured, the surface of the upper end surface of the projection 51 is random. It is possible to always obtain a constant moire fringe even if it has unevenness. In other words, even when the projection 51 has unexpected irregularities on the upper end surface, three-dimensional measurement can be performed without being affected by the morphology unevenness of the upper end surface.
[0038]
Furthermore, in the three-dimensional measuring device and the three-dimensional measuring method according to the first embodiment of the present invention, the edges of the tip of the projection are measured at two locations facing each other, and the average value of the two locations is determined. The three-dimensional measurement of the upper end surface of the pin shape with high measurement accuracy can be performed by using the representative measurement value of That is, the edges of the pin-shaped protrusions 51 existing on the measured object 50 are measured from different angles by using two lights from the two irradiation systems of the first linear irradiation system 1a and the second linear irradiation system 1b. are doing. For example, even when the protrusion 51 is inclined (bent) to the left or right, the average value of the image data from the lower edge and the image data from the upper edge is represented by the representative measurement value. By doing so, it is possible to obtain an accurate measurement value. As a result, it is possible to perform highly accurate three-dimensional measurement even with the projection 51 having an uneven surface on the upper end surface and having a bent distal end.
[0039]
(Second embodiment)
In the three-dimensional measuring apparatus according to the first embodiment, two linear irradiation systems, that is, a first linear irradiation system 1a and a second linear irradiation system 1b are used. The three-dimensional measuring apparatus according to the second embodiment of the present invention uses a single linear irradiation system including a light source 10 and a collimator lens 11, as shown in FIG. Further, the point that the object 50 to be measured is placed on a turntable (turntable) 91 is different from the three-dimensional measuring apparatus according to the first embodiment. The rest is the same as the three-dimensional measuring apparatus according to the first embodiment, and thus redundant description is omitted.
[0040]
Hereinafter, the three-dimensional measuring method according to the embodiment of the present invention will be described with reference to the flowchart of FIG. 6 while referring to FIG.
[0041]
(A) First, in step S201, the grid 30 and the measured object 50 used for three-dimensional measurement are prepared, and the measured object 50 is mounted on the rotating plate 91 arranged on the moving means 80a. Here, the control signal CS is output from the image processing unit 60 and input to the control board 62 in the control device 61.
[0042]
(B) Next, in step S202, the luminance signal LC is output from the control board 62 and input to the light source driving circuit 70. The luminance signal LC is a signal for adjusting the light intensity of the light emitted from the light source 10. Considering that reflected light is obtained from the plurality of edge portions of the protrusion 51, the light emitted from the light source 10 is adjusted to an optimum light intensity by the luminance signal LC.
[0043]
(C) Next, in step S203, a measurement environment for performing three-dimensional measurement is set in the image processing unit 60. The processing in the image processing unit 60 includes setting the number of times of averaging for capturing and averaging the moire fringe image at the same measurement position a plurality of times in accordance with the rotation angle of the turntable (turntable) 91, and setting the inclination of the measurement surface. Setting of an arbitrary area for correction and the like. For example, if the measurement is performed at every rotation angle of 120 °, data from three edge portions of the protrusion 51 that are three-fold symmetrical are taken in, and an average of three points is obtained, thereby enabling more accurate measurement.
[0044]
(D) Next, in step S204, the shift signal SS ₁ Is output and input to the moving means 80a. Input shift signal SS ₁ Thereby, the measured object 50 placed on the moving means 80 is arranged at a desired position. Then, the stage control signal PS is output from the control board 62 and input to the drive unit 42. The drive unit 42 to which the stage control signal PS has been input can control and drive the Z-axis stage 45. Therefore, by moving the grating 30, light is irradiated so as to have a measurement point at the edge of the upper end surface of the protrusion 51.
[0045]
(E) Next, in step S205, irradiation light is emitted from the light source 10 and enters the collimator lens 11, respectively. The light incident on the collimator lens 11 becomes linear parallel light extending in the Y-axis direction, and is incident on the grating 30. The moire fringes of the projections 51 are formed by the parallel light that is not blocked by the light-shielding portion of the grating 30 among the linear parallel light applied to the grating 30.
[0046]
(F) Next, in step S206, the shutter signal FC is output from the control board 62 and input to the camera 20a. When the shutter signal FC is input to the camera 20a, the shutter of the camera 20a is opened, and an image of the first moire fringe generated by the first measurement point on the upper end surface of the projection 51 condensed by the light receiving lens 21 is captured.
[0047]
(G) Next, in step S208, the image of the first moire fringe is output from the camera 20a as the first image analog signal GA (1), and is input to the image capturing board 63. The first image analog signal GA (1) is converted into a digital signal by the image capturing board 63, output as the first image digital signal GD (1), and input to the image processing unit 60. The input first image digital signal GD (1) is stored in the auxiliary storage device in the image processing unit 60.
[0048]
(H) Further, it is determined whether there is a measurement point on the measured object 50, and if so, the process proceeds to step S217. In step S217, the control board 62 outputs a shift signal SS of, for example, 120 ° rotation. ₂ Is output to the rotating plate 91. The shift signal SS is supplied to the rotating plate 91. ₂ Is input, the rotating plate 91 rotates, for example, 120 ° clockwise, and moves the center point of the measurement point to the edge rotated 120 ° from the previously measured edge position. Then, the process returns to step S205.
[0049]
(I) Next, in step S205, irradiation light is emitted again from the light source 10 and enters the grating 30. Moire fringes from the edge of the protrusion 51 rotated by 120 ° are formed by the parallel light that is not blocked by the light-shielding portion of the grating 30 among the linear parallel light applied to the grating 30. Next, in step S206, the shutter signal FC is output from the control board 62 and input to the camera 20a. When the shutter signal FC is input to the camera 20a, the shutter of the camera 20a is opened, and an image of the second moire fringe generated by the edge (second measurement point) rotated by 120 ° is captured. Next, in step S208, the image of the second moiré fringe is output from the camera 20a as the second image analog signal GA (2), and is input to the image capturing board 63. The second image analog signal GA (2) is converted into a digital signal by the image capturing board 63, output as the second image digital signal GD (2), and input to the image processing unit 60. The input second image digital signal GD (2) is stored in the auxiliary storage device in the image processing unit 60.
[0050]
(U) Further, it is determined whether or not there is a measurement point on the measured object 50, and in step S217, the shift signal SS further rotated by 120 ° ₂ Is output to the rotating plate 91. The shift signal SS is supplied to the rotating plate 91. ₂ Is input, the rotating plate 91 further rotates 120 °, and moves the center point of the measurement point from the previously measured edge position to the edge further rotated 120 °. Then, the process returns to step S205.
[0051]
(R) Next, in step S205, irradiation light is emitted again from the light source 10 and enters the grating 30. The moire fringes from the edge of the protrusion 51 further rotated by 120 ° are formed by the parallel light, which is not blocked by the light-shielding portion of the grating 30, of the linear parallel light applied to the grating 30. Next, in step S206, the shutter signal FC is output from the control board 62 and input to the camera 20a. When the shutter signal FC is input to the camera 20a, the shutter of the camera 20a is opened, and an image of the third moiré fringe generated by the edge (third measurement point) further rotated by 120 ° is captured. Next, in step S208, the image of the third moiré fringe is output from the camera 20a as the third image analog signal GA (3), and is input to the image capturing board 63. The third image analog signal GA (3) is converted into a digital signal by the image capturing board 63, output as the third image digital signal GD (3), and input to the image processing unit 60. The input third image digital signal GD (3) is stored in the auxiliary storage device in the image processing unit 60. Further, it is determined whether there is a measurement point on the measured object 50, and if it is determined that three measurement points have been completed, the process proceeds to step S209.
[0052]
(ヲ) Next, in step S209, an average value is calculated from the first image digital signal GD (1), the second image digital signal GD (2), and the third image digital signal GD (3). That is, the image processing unit 60 calculates the average value of the first image digital signal GD (1), the second image digital signal GD (2), and the third image digital signal GD (3) as a representative measurement value. The calculated representative measurement value is treated as a measurement result of the tip position of the protrusion 51.
[0053]
(W) Finally, in step S210, the three-dimensional measurement data obtained in step S209 is stored in the auxiliary storage device of the image processing unit 60.
[0054]
As described in the first embodiment, the edge of the tip of the cylinder always has an arc-shaped topology even if the upper end surface of the projection 51 has irregularities. According to the three-dimensional measuring device and the three-dimensional measuring method according to the second embodiment of the present invention, since the moire fringe from the edge of the tip of the projection is measured, the surface of the upper end surface of the projection 51 is random. It is possible to always obtain a constant moire fringe even if it has unevenness. In other words, even when the projection 51 has unexpected irregularities on the surface of the upper end surface, it is possible to perform highly accurate three-dimensional measurement without being affected by the morphology unevenness of the upper end surface. Become.
[0055]
Furthermore, according to the three-dimensional measuring device and the three-dimensional measuring method according to the second embodiment of the present invention, even if there is one linear irradiation system, the edge of the tip part is measured at a plurality of positions, The average value of the location can be used as a representative measurement value of the tip position. Since only one linear irradiation system is required, maintenance of the light source and adjustment of the irradiation system are easier than in the first embodiment.
[0056]
In the above example, the average value of the three points rotated by 120 ° is calculated. However, the average value of the two points may be calculated by rotating the image by 180 °. Alternatively, another average value may be obtained.
[0057]
(Third embodiment)
As shown in FIG. 7, the three-dimensional measuring apparatus according to the third embodiment of the present invention is different from the three-dimensional measuring apparatus according to the first embodiment in that it has only a single linear irradiation system 1s. Is different. The three-dimensional measuring apparatus according to the third embodiment of the present invention has an irradiation system moving unit 90 as shown in FIG. 7, and the irradiation system moving unit 90 moves the linear irradiation system 1s. This is different from the three-dimensional measurement apparatus according to the first embodiment in that the three-dimensional measurement apparatus according to the first embodiment is configured to perform the measurement. The irradiation system moving means 90 employs a method of rotating by 180 ° using a rotating plate (turntable) having a rotation axis perpendicular to the lattice plane at the center of the lattice. The irradiation system moving means 90 that moves on a straight line may be used, but in this case, adjustment of the irradiation angle with respect to the lattice plane is required for each movement.
[0058]
In the three-dimensional measuring apparatus according to the third embodiment of the present invention, the first linear irradiation system 1a shown in FIGS. 1 and 2 is used by using a single linear irradiation system 1s irradiation system moving means 90. Move from the position to the position of the second linear irradiation system 1b, and irradiate the lattice 30 with light at each position to form moire fringes. For this reason, similarly to the first embodiment, the edge of the tip of the projection is measured at two locations facing each other, and the average value of the two locations can be used as a representative measurement value of the location of the tip. Highly accurate three-dimensional measurement of the upper end surface of the pin shape is possible. Then, the average value of the image data from the two opposite edges of the upper end surface of the protrusion is used as the representative measurement value of the tip position, so that three-dimensional measurement with high measurement accuracy is performed as in the first embodiment. Can be. Also, even if the surface of the upper end surface of the projection has random irregularities and is inclined or bent, three-dimensional measurement can be performed without being affected by the morphology or inclination of the surface of the upper end surface.
[0059]
Thus, even if it is a single linear irradiation system 1s, by providing the irradiation system moving means 90, the first linear irradiation system 1a and the second linear irradiation system 1 of the three-dimensional measuring apparatus according to the first embodiment are provided. It is possible to provide a function equivalent to the two linear irradiation systems of the linear irradiation system 1b. Then, since only the single linear irradiation system 1s needs to be provided, there is an advantage that maintenance of the light source and adjustment of the irradiation system are easy as compared with the first embodiment.
[0060]
(Other embodiments)
As described above, the present invention has been described with reference to the first to third embodiments. However, it should not be understood that the description and drawings forming a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art.
[0061]
For example, in the three-dimensional measurement apparatus according to the first embodiment of the present invention, the first and second linear irradiation systems are provided, and the edges of the tips of the protrusions are measured at two locations facing each other. The average value of the two points was used as a representative measurement value of the tip position. In the three-dimensional measurement apparatus according to the second embodiment, the object to be measured is rotated instead of having the first and second linear irradiation systems, and the three-dimensional measurement according to the third embodiment is performed. In the apparatus, a single linear irradiation system was moved to irradiate the grating with parallel light from different directions, and the average of a plurality of measured values was used as a representative measured value of the tip position. However, when the directions of the projections are uniform or when only relatively low measurement accuracy is required, a single linear irradiation system is used to obtain only data from one edge and use this as a representative measurement. It may be a value.
[0062]
In the first embodiment, the first light source 10a and the second light source 10b as “line light sources” are, for example, monochromatic light sources that are columnar light sources extending in the Y-axis direction such as a fluorescent discharge tube, a low-pressure mercury lamp, and a xenon lamp. Although a case where the light source is used via a filter or a spectroscope to exemplify the light source is exemplified, various modes are possible as the line light source. As shown in FIG. 8, a point light source 10 such as a light emitting diode or a semiconductor laser is used. _i-1 , 10 _i , 10 _{i + 1} ,... May be used as the light source 10c in which the light source 10c is disposed in close contact with the light source table 13 in the Y-axis direction. Since light-emitting diodes and semiconductor lasers are monochromatic light sources, no filters or spectrometers are required to make them monochromatic light sources. When the light source 10 shown in FIG. 8 is used for three-dimensional observation, the measurement points at the edge portion of the tip of the projection 51 are, as shown in FIG. _i-1 , 10 _i , 10 _{i + 1} An elephant is projected. However, the point light source 10 _i-1 , 10 _i , 10 _{i + 1} ,... Can be performed in the same manner as when a line light source is used. Change the shape of the collimator lens to a point light source 10 _i-1 , 10 _i , 10 _{i + 1} The point light source 10 is designed by considering the design in consideration of the position of the point light source. _i-1 , 10 _i , 10 _{i + 1} ,... Can be reduced.
[0063]
As described above, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the matters specifying the invention described in the claims appropriate from this disclosure.
[0064]
【The invention's effect】
According to the present invention, it is possible to provide a three-dimensional measuring device and a three-dimensional measuring method with high measurement accuracy, which are not affected by the morphology of the shape of the upper end surface.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a three-dimensional measuring device according to a first embodiment of the present invention.
FIG. 2 is a specific schematic diagram of the three-dimensional measuring device according to the first embodiment of the present invention.
FIG. 3 is a flowchart of a three-dimensional measuring method using the three-dimensional measuring device according to the first embodiment of the present invention.
FIG. 4 is a schematic diagram of the vicinity of the tip end of the measured object measured by the three-dimensional device according to the first embodiment of the present invention.
FIG. 5 is a specific schematic diagram of a three-dimensional measurement device according to a second embodiment of the present invention.
FIG. 6 is a flowchart of a three-dimensional measurement method using a three-dimensional measurement device according to a second embodiment of the present invention.
FIG. 7 is a conceptual diagram showing a three-dimensional measuring device according to a third embodiment of the present invention.
FIG. 8 is a diagram of a light source according to another embodiment of the present invention.
FIG. 9 is a schematic diagram of the vicinity of the tip end of the measured object measured by the light source in FIG. 8;
[Explanation of symbols]
1: Linear irradiation system
1a 1st linear irradiation system
1b 2nd linear irradiation system
2 ... Receiver
4: Grid position control unit
10, 10a, 10b, 10c ... light source
10i ... Point light source
11a: First collimator lens
11b ... second collimator lens
13. Light source stand
20 ... Image sensor
20a… Camera
21 ... Light receiving lens
30 ... Lattice
31 ... Light receiving part
41 ... moving mechanism
42 ... Drive section
43 ... Control system
45 ... Z axis stage
50, 50a ... object to be measured
51 ... projection
60 ... Image processing unit
61 ... Control device
62 ... Control board
63… Image capture board
70 ... Light source drive circuit
80,80a ... Transportation means
90 ... Irradiation system moving means
91 ... Rotating plate

Claims (16)

A grid in which slits extending in the Y-axis direction are arranged on the XY plane at a constant pitch,
A lattice position control unit that keeps the plane of the lattice substantially parallel to the XY plane and moves the lattice relative to the measured object in the Z-axis direction orthogonal to the XY plane;
For the grating, a linear irradiation system that emits linear parallel light along the Y axis,
A light receiving unit that captures an image of a moiré fringe of the measured object through the grid,
An image processing unit for converting the image data of the moire fringes taken into the light receiving unit into three-dimensional measurement data. The three-dimensional measuring apparatus according to claim 1, wherein the object to be measured is a columnar object. The three-dimensional measurement apparatus according to claim 2, wherein the light receiving unit captures an image of a moire fringe from an edge formed by an upper end surface and a side surface of the columnar object. The three-dimensional measurement apparatus according to claim 2, wherein the light receiving unit captures moire fringe images from a plurality of positions of an edge portion formed by an upper end surface and a side surface of the columnar object. The three-dimensional measurement apparatus according to claim 4, wherein the image processing unit sets an average value of image data from the plurality of positions as a representative measurement value. The three-dimensional measurement apparatus according to claim 4, wherein the linear irradiation system includes a plurality of linear irradiation systems. The three-dimensional measurement apparatus according to claim 4, further comprising an irradiation system moving unit that moves a position of the linear irradiation system so as to emit parallel light from different directions with respect to the grating. The three-dimensional measuring apparatus according to claim 4, wherein the object to be measured is placed on a rotating plate, and images of moiré fringes from a plurality of positions of the edge portion are captured by rotation of the rotating plate. A lattice plane in which slits extending in the Y-axis direction are arranged on the XY plane at a constant pitch is kept substantially parallel to the XY plane, and the Z-axis direction orthogonal to the XY plane with respect to the measured object. Moving to
Emitting linear parallel light along the Y-axis to the grating;
Capturing an image of moiré fringes of the measured object through the grid;
Converting the image into three-dimensional measurement data. The three-dimensional measurement method according to claim 9, wherein the object to be measured is a columnar object. The three-dimensional measurement method according to claim 10, wherein the step of capturing the image captures an image of moire fringes from an edge portion formed by an upper end surface and a side surface of the columnar object. The three-dimensional measurement method according to claim 10, wherein the step of capturing the image captures moire fringe images from a plurality of positions of an edge portion formed by an upper end surface and a side surface of the columnar object. 13. The three-dimensional measurement method according to claim 12, wherein the step of converting into the three-dimensional measurement data sets an average value of image data from the plurality of positions as a representative measurement value. The three-dimensional measurement method according to claim 12, wherein the step of emitting the parallel light emits the light from a plurality of the linear irradiation systems. The three-dimensional measurement method according to claim 12, wherein in the step of emitting the parallel light, the position of the linear irradiation system is moved to emit the parallel light from different directions with respect to the grating. The three-dimensional measurement method according to claim 12, wherein the step of emitting the parallel light includes rotating the object to be measured to capture moire fringe images from a plurality of positions of the edge portion.

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