JP2009074876A - Measuring device, and method of measuring the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring device capable of highly accurate measurement of an object to be inspected depending on a surface shape of the object by using a difference in focuses due to chromatic aberration, and to provide a method of measuring the same. <P>SOLUTION: The measuring device 1 includes an image sensor 20 having a plurality of pixels 21, a coloring lens 11 for forming an image of a surface of the object 8 to be inspected on the image sensor, a zooming driver 11a capable of enlarging or reducing the image by moving at least part of lenses constituting the coloring lens 11 in the direction of an optical axis, and an arithmetic processing unit 30 for calculating a relative position in the optical axis direction on the surface of the object for measuring a three-dimensional shape of the object based on intensity of light received by each of pixel regions while the image of the surface of the object is enlarged or reduced by the zooming driver 11a and formed on the image sensor 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a measuring device that measures a three-dimensional shape of a test object, and a measuring method using the measuring device.

  Conventionally, 3D measurement is an important technology applied and used in various fields such as object recognition in robot vision, motion pictures for analyzing human movement, ambient image processing in in-vehicle cameras, and archives of buildings. It is. Examples of three-dimensional measurement methods include a stereo camera that uses the principle of triangulation, a light cutting method that uses laser slit light, and a measurement method that uses a focal difference due to chromatic aberration. As a three-dimensional measurement method using the focal difference due to chromatic aberration, for example, the one shown in Patent Document 1 is known, and FIG. 8 shows the three-dimensional shape of a test object using the focal difference due to chromatic aberration. 1 shows a measuring device 200 as an example of a measuring device.

  In the following description of the measuring apparatus 200, for convenience of explanation, the following description will be made with the arrow direction shown in FIG. In the measuring apparatus 200, illumination light including a plurality of wavelength components emitted from the light source 201 passes through the pinhole 202, passes through the beam splitter 203, and then is collected by the imaging lens system lens 204 to be inspected 205. It is comprised so that it may be irradiated. The illumination light reflected by the test object 205 is reflected by the beam splitter 203, passes through the pinhole 206, and enters the photodetector 207.

Here, in general, the focal length f of a lens is approximately expressed by equation (1) using the refractive index n of the glass material constituting the lens and the curvature radii r1 and r2 of the lens.
(1 / f) = (n−1) × {(1 / r1) − (1 / r2)} (1)
It is expressed. Here, the focal length f depends on the refractive index n of the lens, and further, the refractive index n of the lens depends on the wavelength of the illumination light passing therethrough. As a result, the focal position of the illumination light depends on the wavelength in the optical axis direction. Different positions. This is chromatic aberration, and the measuring apparatus 200 is configured to measure the surface of the test object 205 using the fact that the focal positions of illumination lights having different wavelengths are shifted in the optical axis direction. .

  In FIG. 8, the test object 205 is irradiated with the blue illumination light 201 </ b> B having the wavelength λ <b> 1, the green illumination light 201 </ b> G having the wavelength λ <b> 2, and the red illumination light 201 </ b> R having the wavelength λ <b> 3 collected by the imaging lens system 204. Indicates. Each wavelength has a magnitude relationship of λ1 <λ2 <λ3. Here, the green illumination light 201G with the wavelength λ2 is focused on the top of the test object 205, and the blue illumination light 201B with the wavelength λ1 shorter than the green illumination light 201G has a short focal length, so the test object 205 is short. Focus on the left side of the top. On the other hand, the red illumination light 201R having the wavelength λ3 longer than the green illumination light 201G is focused on the right side of the top of the test object 205. Of the three illumination lights 201 </ b> B, 201 </ b> G, and 201 </ b> R, the most green illumination light 201 </ b> G focused on the top of the test object 205 is reflected by the beam splitter 203 and enters the photodetector 207. The photodetector 207 is configured to obtain the height (in the left-right direction) of the test object 205 as the in-focus position of the green illumination light 201G by receiving the most amount of the green illumination light 201G.

JP-A-10-9827

  However, the measurement apparatus 200 is configured to perform measurement for each limited region (focused point) limited using chromatic aberration, and accordingly, for example, according to the surface shape of the test object 205, a complicated surface is used. It was impossible to measure the shape portion in more detail and to measure a uniform surface shape portion over a wide range. Therefore, it is difficult to measure the shape with high accuracy according to the surface shape of the test object 205.

  In view of the problems as described above, it is an object of the present invention to provide a measuring apparatus and a measuring method thereof capable of performing high-accuracy measurement according to the surface shape of a test object using a focal difference due to chromatic aberration. .

  In order to solve the above problems, a measuring apparatus according to the present invention includes an image sensor having a plurality of pixels arranged in a plane, and light from the surface of a test object is incident on the image sensor. An imaging lens system that forms an image of the surface of the specimen, and at least a part of the lenses that constitute the imaging lens system are moved in the optical axis direction with respect to the specimen and connected to the image sensor. A zoom lens driving unit capable of enlarging or reducing the size of the image to be imaged, and a zoom lens driving unit enlarging or reducing the size of the image to form an image of the surface of the test object on the image sensor. In the imaged state, based on the intensity of light received by each of the plurality of pixels constituting the image sensor, the relative position in the optical axis direction of the surface of the test object is calculated to calculate the position of the test object. 3D It is configured by an arithmetic processing unit that measures Jo. The plurality of pixels receive light from the surface of the test object by dividing the light into at least two wavelengths and detect the received light intensity for each wavelength, and the arithmetic processing unit in the image of the surface of the test object From the relationship between the difference between the received light intensity of two wavelengths at a predetermined reference position and the difference between the received light intensity of the two wavelengths at other positions in the image of the surface of the test object, The distance between the other positions is obtained, and the three-dimensional shape of the surface of the test object is measured.

  In the measuring apparatus having the above-described configuration, an autofocus lens driving unit capable of moving at least a part of the lenses constituting the imaging lens system in the optical axis direction with respect to the test object, and the imaging lens The autofocus lens drive unit moves the at least some of the lenses in the optical axis direction so that the image sensor focuses an image of the predetermined reference position on the test object. It is preferable to have an autofocus control unit to control. In the measuring apparatus having the above configuration, it is preferable that the predetermined reference position on the surface of the test object is a position on the optical axis of the imaging lens system on the surface of the test object.

  In the measuring method using the measuring apparatus having the above-described configuration, the zoom lens driving unit moves the at least a part of the lenses constituting the imaging lens system with respect to the object to be connected to the image sensor. Zooming step for enlarging or reducing the size of the image to be imaged, and light reception for detecting the light receiving intensity for each wavelength while the plurality of pixels receive light from the surface of the test object divided into at least two wavelengths An intensity detection step, and the arithmetic processing unit compares the received light intensity of two wavelengths at a predetermined reference position in the image of the surface of the test object, and the 2 at other positions in the image of the surface of the test object. A measurement step of measuring the three-dimensional shape of the surface of the test object by determining the distance of the other position with respect to the predetermined reference position from the relationship with the difference in the received light intensity of two wavelengths. Door is preferable.

  According to the measurement apparatus and the measurement method according to the present invention, it is possible to perform high-accuracy measurement according to the surface shape of the test object using the focal difference due to chromatic aberration.

  Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. For convenience of explanation, the directions of the arrows shown in FIGS. 1 to 6 are defined as front, rear, left, right, up and down directions.

  FIG. 1 shows a measuring apparatus 1 according to the present invention. This measuring device 1 is mainly composed of a light source 5, an illumination lens system 6, a multidot pattern 7, a half mirror 10, a color developing lens system 11, an image sensor 20, and an arithmetic processing unit 30. This is a configuration generally called an active method for irradiating auxiliary light for measurement. The light source 5 is a light source that can emit illumination light 5a toward the illumination lens system 6. As the light source 5, for example, a white light source such as a halogen lamp, or RGB (in the following, red, green, and blue are shown in order) LED) composed of three colors is used. The illumination lens system 6 is actually composed of a plurality of lenses, condenses the illumination light 5a emitted from the light source 5 (advancing from below to above), and the collected illumination light 5a is a multi-dot. Pattern 7 is reached.

  The multidot pattern 7 is formed in a flat plate shape and is arranged so as to intersect perpendicularly with the optical axis of the illumination lens system 6. In addition, as shown in FIG. 6A, the multi-dot pattern 7 has multi-spots 7a that are open at regular positions at regular intervals in the front-rear and left-right directions on the surface intersecting the optical axis of the illumination lens system 6. A plurality are provided. Here, the multi-dot pattern 7 is disposed at the in-focus position (in-focus surface) of the illumination light 5 a collected by the illumination lens system 6. The half mirror 10 is a mirror having a function of reflecting a part of incident light and transmitting a part thereof, and the ratio of reflected light to transmitted light is approximately 1: 1. The half mirror 10 is installed in a state inclined by 45 degrees with respect to the optical axis of the illumination lens system 6.

  The color developing lens 11 is actually constituted by an imaging lens system composed of a plurality of lenses, and this imaging lens system is a lens in which chromatic aberration is not corrected (geometric aberration is corrected and only chromatic aberration is provided). It is a system. The color developing lens 11 is provided with a zooming driving device 11a. By operating the zooming driving device 11a, at least one lens (hereinafter referred to as a zoom lens) among the lenses constituting the color developing lens 11 is operated. Is configured to move in the optical axis direction (left-right direction) of the color developing lens 11. By moving in this way, the image picked up by changing the focal length of the color developing lens 11 can be enlarged or reduced. Further, when a measurer performs a zoom operation, a differential signal is input to the zooming control unit 11b, and the zooming control unit 11b controls the operation of the zooming drive device 11a based on the differential signal. The zoom lens moved by the zooming driving device 11a is detected by an encoder (not shown) and output to the arithmetic processing unit 30 and the arithmetic processing unit 30 outputs the movement amount in the right and left direction and the left and right direction. The movement amount is memorized.

  Further, the color developing lens 11 is provided with an autofocus driving device 11c, and the autofocus driving device 11c includes at least one lens (hereinafter referred to as an autofocusing lens) among the lenses constituting the color developing lens 11. In other words, a lens different from the zoom lens) is automatically moved in the optical axis direction (left-right direction) of the color developing lens 11 according to a differential signal value described later. The differential signal can be determined by the sign of its positive or negative sign to determine whether it is defocused to the left or right, and how much it is deviated depending on its magnitude (absolute value). By moving the autofocus lens in this way, It is possible to focus on a desired measurement area. That is, the differential signal is fed back and input to the autofocus control unit 11d, and the autofocus control unit 11d controls the autofocus driving device 11c so that the differential signal value becomes zero. The position where the differential signal value becomes zero is the position where the focus is achieved. The left and right position and the amount of movement in the left and right direction of the autofocus lens moved by the autofocus driving device 11c are detected by an encoder (not shown) and output to the arithmetic processing unit 30. Stores this amount of movement.

  As shown in FIG. 4, the image sensor 20 includes a plurality of substantially square pixel regions 21 arranged in a plane in the front-rear and up-down directions. Each pixel region 21 transmits light according to RGB wavelengths (by color). ) Have RGB light receiving portions (not shown) capable of receiving light. The arithmetic processing unit 30 is a processing unit that calculates the three-dimensional shape of the test object 8 based on the received light intensity obtained by receiving light for each wavelength in the pixel region 21 of the image sensor 20. The calculation method of will be described later. In addition, the three-dimensional shape data of the test object 8 obtained in the arithmetic processing unit 30 can be visually confirmed by, for example, being output to the monitor 100 provided outside the measuring apparatus 1. .

  The member configuration of the measurement apparatus 1 has been described so far. Hereinafter, the progress of the illumination light 5a emitted from the light source 5 and the reflected light 5b from the surface of the test object 8 will be described.

  Illumination light 5 a emitted from the light source 5 and traveling toward the illumination lens system 6 (upward) enters the illumination lens system 6 and is collected, and then reaches the multi-dot pattern 7. Of the irradiation light 5a that has reached the multi-dot pattern 7, the illumination light 5a that has reached the multi-spot 7a portion passes through the multi-dot pattern 7, and 5a that has reached the other portion does not pass through the multi-dot pattern 7. It has a configuration. The illumination light 5a that has passed through the multi-dot pattern 7 is reflected by the surface of the half mirror 10 and travels by changing the traveling direction from upper to left by 90 degrees. Then, the illumination light 5a incident on the color developing lens 11 is irradiated on the test object 8 without correcting the chromatic aberration.

  When the illumination light 5a is irradiated onto the test object 8, as shown in FIG. 1, the surface of the test object 8 is regularly arranged with a certain interval, and the illumination light 5a is irradiated and becomes brighter. The reference dot 7b is formed. Those formed on the optical axis of the color developing lens 11 are referred to as reference dots 7c, and those formed at positions other than on the optical axis of the color developing lens 11 are referred to as reference dots 7d and 7e. The reference dots 7b are the reference dots 7c. The reference dots 7d and 7e are all included. Here, the arrangement position and shape of the reference dot 7 b correspond to the multi-spot 7 a formed in the multi-dot pattern 7. A part of the illumination light 5a irradiated on the surface of the test object 8 is reflected on the surface of the test object 8 to become reflected light 5b, and enters the coloring lens 11 and passes through the half mirror 10. The image is formed on the image sensor 20. The reflected light 5 b imaged by the image sensor 20 is received by the RGB light receiving portions formed in the pixel region 21, and the light reception results are output to the arithmetic processing unit 30. The arithmetic processing unit 30 calculates the three-dimensional shape of the test object 8 based on these light reception results, and a specific calculation method will be described later.

  Up to here, the progression of the illumination light 5a and the reflected light 5b from the surface of the test object 8 has been described. In the following, referring to FIGS. 2 and 3, the optical axis direction on the test object surface is described. The relationship between the level difference and the blur of the captured image will be described.

  FIG. 2 shows a state in which the three-dimensional shape measurement of the test objects 22, 23, and 24 is performed using the measuring apparatus 1 (partially not shown). Here, the positional relationship between the test objects 22, 23 and 24 is that the test object 24 is leftmost in the optical axis direction of the color developing lens 11 (the furthest away from the color developing lens 11), and is in the middle position. The object 23 and the test object 22 are located on the rightmost side. For example, an image shown in FIG. 3A is obtained at the B light receiving portion formed in the pixel region 21 of the image sensor 20 by imaging the test objects 22, 23, and 24, and similarly, the G light reception is performed. 3B, and the image shown in FIG. 3C is obtained at the R light receiving portion. The light of the wavelength B is focused at, for example, the left and right positions of the test object 22 and is not focused at the positions of the test objects 23 and 24. Therefore, as shown in FIG. The image 22B is captured most clearly, and the images 23B and 24B of the test objects 23 and 24 are blurred. Further, the light of G wavelength is focused at the position of the test object 23, and the light of R wavelength is focused at the position of the test object 24, and the test objects 22, 24 in FIG. The images 22G and 24G and the images 22R and 23R of the test objects 22 and 23 in FIG. 3C are blurred. In this way, a step or the like in the optical axis direction on the surface of the test object can be detected by blurring the captured image. The relationship between the level difference and the image blur amount will be described later.

  Up to this point, the member configuration of the measuring device 1 has been described. Hereinafter, the measuring method for measuring the three-dimensional shape of the test object 8 using the measuring device 1 will be described with reference to the flowchart shown in FIG. To do.

  In step 1, a data table for determining the relative height Z in the left-right direction with respect to the reference dot 7 c formed on the optical axis of the color developing lens 11 is created. First, an operation switch (not shown) of the autofocus driving device 11c is turned off so that the autofocus function does not work. Then, the illumination light 5 a is irradiated on the surface of the test object 8, and an image of the reference dot 7 c formed on the optical axis of the color developing lens 11 on the surface of the test object 8 is displayed in the pixel region 21 of the image sensor 20. An image is formed, and the received light intensity is detected for each of the RGB wavelengths. At this time, for example, the coloring lens 11 is moved in the left-right direction (the optical axis direction of the coloring lens 11), and the received light intensity of the received light is determined based on the image of the reference dot 7c imaged at each moving position. Ask. The obtained light reception intensities are output to the arithmetic processing unit 30, and the arithmetic processing unit 30 normalizes the light reception intensities for each wavelength so that the maximum value of the light reception intensity is 1, for example. By normalizing in this way, the received light intensity that is not affected by the light intensity of the reflected light 5b and the reflectance of the surface of the test object 8 can be obtained.

  The standardized light receiving intensity will be described with reference to FIG. 4. The image of the reference dot 7c on the image sensor 20 is slightly shifted in the left-right direction from the focused position, for example, the image 22c at the focused left-right height position. It is assumed that the image 22b is captured in a circle like the image 22b at a certain position, and the image 22a at a position further deviated in the left-right direction from the focus position. At this time, for example, if the light reception intensity at the center of the image 22c is 10 and the diameter of the image 22c is 10, light reception intensity / diameter = 10/10 = 1 is calculated, and this value is normalized. In addition, the received light intensity is 1 which is the maximum value because of the in-focus position. Further, by forming an image at a position shifted in the left-right direction from the focal position, the received light intensity at the center of the image is lowered and the diameter of the image is increased. For example, the standardized received light intensity of the image 22b is received light intensity / diameter = 5/15 = 0.33, and the standardized received light intensity of the image 22a is received light intensity / diameter = 2/20 = 0.1. Is calculated as follows.

  Graphs obtained by taking the normalized received light intensities obtained as described above for each wavelength, taking the received light intensity on the vertical axis, and the horizontal height Z relative to the reference dot 7c in the horizontal direction. This is shown in FIG. The intensity curve 8B shown in FIG. 5A is a curve obtained from an image of B wavelength, the intensity curve 8G is an image of G wavelength, and the intensity curve 8R is a curve obtained from an image of R wavelength. Here, in the intensity curves 8B, 8G, and 8R, the received light intensity has a peak value 1 at distances Z5, Z0, and Z6, respectively. Further, by calculating the difference value by subtracting the intensity curve 8B from the intensity curve 8R, a differential curve 8S in which the vertical axis represents the differential signal and the horizontal axis represents the relative height Z in the left-right direction with respect to the reference dot 7c is obtained. Is obtained (see FIG. 5B).

  Here, as shown in FIG. 5A, the horizontal height Z0 at which the reference dot 7c is located is a position at which the received light intensity of the intensity curve 8G is substantially peaked (light with a wavelength of G is in focus). ), And the intensity curve 8B and the intensity curve 8R cross each other, and the differential signal value is zero. After calculating the standardized received light intensity at the other reference dot 7d to obtain a differential signal, by referring to the differential curve 8S, the relative height in the left-right direction with respect to the reference dot 7c, including the left-right direction, is also determined. Z can be obtained. As shown in FIG. 5B, the differential curve 8S is substantially linear in the measurable region W from about Z5 to Z6 about the horizontal height Z0 where the reference dot 7c is located. Thus, this is an area where the correspondence between the differential signal and the relative height Z in the left-right direction is obtained with high accuracy. Therefore, the calculation of the relative height Z in the left-right direction described below is performed with reference to the measurable area W.

  Proceeding to step 2, after the operation switch of the autofocus drive device 11c is turned on and the autofocus function is activated, the measurable area W from Z5 to Z6 centered on the horizontal height Z0 of the reference dot 7c. An image of the reference dot 7d formed at a position out of the range is taken. At this time, the autofocus drive device 11c changes the focal position of the color developing lens 11 by moving the autofocus lens so that the differential signal value at the reference dot 7d becomes zero. When the differential signal value at the reference dot 7d becomes zero, the autofocus control unit 11d stops the operation of the autofocus drive device 11c and stops the movement of the autofocus lens. In this way, an autofocus function for automatically focusing on the position of the reference dot 7d is realized.

  Proceeding to step 3, in the state in which the position of the reference dot 7d is focused in step 2, an image of the reference dot 7e that is not located on the optical axis of the color developing lens 11 is captured. The reference dot 7e is included in the measurable area W in the differential curve 8S in a state where the reference dot 7d is focused on. Here, the zooming driving device 11a is operated so that the size of the image of the reference dot 7e becomes a desired size with respect to the plurality of pixel regions 21 of the image sensor 20. By doing so, the focal length of the color developing lens 11 is changed to enlarge or reduce the size of the image of the reference dot 7e. For example, by moving the zoom lens to the wide side, an image of a wide area including the periphery of the reference dot 7e can be obtained. On the other hand, by moving the zoom lens to the tele side, it is possible to obtain an image in which a small area of a part of the test object 8 is enlarged.

  Proceeding to step 4, in a state where the movement of the autofocus lens and the zoom lens is stopped, the standardized received light intensity of the reference dot 7e is detected for each wavelength in the same manner as in the case of the reference dot 7c. Then, the differential signal s1 at the position of the reference dot 7e is obtained on the basis of the standardized received light intensity for each wavelength.

  Proceeding to step 5, by referring to the measurable area W of the differential curve 8S, the relative height Z1 in the left-right direction corresponding to the differential signal s1 obtained in step 4 can be obtained. Further, at the positions of the autofocus lens and the zoom lens, the relative height Z1 in the left-right direction is simultaneously obtained for each reference dot 7b that can be imaged. Further, for each reference dot 7b that cannot be imaged due to a blurred image at the position of the autofocus lens, the autofocus driving device 11c focuses the focus of the color developing lens 11 on the basis of the reference dot 7d. Change the position and take an image. At this time, the zooming driving device 11a is appropriately operated according to the surface shape of the test object 8. Then, after obtaining the standardized received light intensity for each reference dot 7b, the differential signal is calculated, and the relative height Z1 in the left-right direction corresponding to each differential signal is obtained with reference to the differential curve 8S. . By doing so, the relative height in the left-right direction of each reference dot 7b is calculated with reference to the height Z0 in the left-right direction of the reference dot 7c formed on the optical axis of the color developing lens 11.

  Proceeding to step 6, each reference dot 7b formed on the surface of the test object 8 and the image of each reference dot 7b formed on the planar image sensor 20 have a one-to-one correspondence. Therefore, the three-dimensional shape of the surface of the test object 8 is obtained by combining the relative height in the left-right direction of each reference dot 7b calculated in step 5 and the front / rear / up / down positions on the image sensor 20. Ends.

  To briefly summarize the effects of the measurement apparatus 1 according to the present invention, the size of an image formed in the pixel region 21 is desired in three-dimensional shape measurement that is performed by using chromatic aberration that inevitably occurs in a general imaging optical system. It has a zooming function for continuously enlarging or reducing so as to be the size of. Therefore, the location where the 3D shape measurement is performed in more detail is performed by enlarging the image by the zooming function, while the location where the 3D shape measurement is performed over a wide range is performed by reducing the image and performing the imaging. The three-dimensional shape measurement according to the surface shape of the object 8 becomes possible.

  In the step 2 in the above-described embodiment, in a state where the position of the reference dot 7d is automatically focused, a position where the standardized received light intensity of the G wavelength with respect to the image of the reference dot 7d becomes a peak is obtained. It is also possible to confirm whether or not the position of the reference dot 7d is substantially focused from the received light intensity.

  By incorporating the autofocus function shown in the above-described embodiment into an imaging apparatus such as a camera, for example, the autofocus function attached to the camera or the like becomes unnecessary. Also, in an imaging apparatus other than a camera or the like, an autofocus function can be realized by also using a chromatic aberration optical system in the apparatus.

  In the above-described embodiment, each of the RGB light receiving portions is formed in the pixel region 21 of the image sensor 20, but the present invention is not limited to this configuration. For example, a three-dimensional CCD that can independently obtain RGB images. The structure in which is formed may be used.

  In the above-described embodiment, the received light intensity of the reference dot 7c is normalized by dividing it by the width of the image in step 1, but the normalization of the received light intensity is not limited to this method. A method of dividing by the average received light intensity, a method of dividing the image width by the average received light intensity, a method by Fourier transform, or the like may be used.

  In the above-described embodiment, the multi-dot pattern 7 for forming the dot-like reference dots 7b on the surface of the test object 8 is used. However, the present invention is not limited to this configuration. For example, the lattice pattern 3 shown in FIG. The measuring apparatus 1 may be configured using the fringe pattern 4 shown in FIG. Further, when the grid pattern 3 is used, an image of a grid point 3c that is an intersection of the left and right grids 3a and the top and bottom grids 3b is used as a measurement point for measuring the three-dimensional shape of the test object 8 (for example, the reference dot 7b in the embodiment). It is possible.

  In the above-described embodiment, the dot-shaped reference dot 7b is formed on the surface of the test object 8 using the illumination optical system, and is generally called an active method. However, the present invention is not limited to this configuration. Without using an optical system, for example, the natural light is used to detect the received light intensity of the surface feature points (edge portions, contrast changing portions, etc.) of the test object 8 to obtain the three-dimensional shape of the test object 8. A configuration generally called a passive system may be used.

  In the above-described embodiment, the data table is created by using the two wavelengths R and B in Step 1, but the data table creation is not limited to the configuration created by these two wavelengths, and is arbitrary. It is possible to create a data table by combining two different wavelengths.

  In the above-described embodiment, the surface of the test object 8 is preferably composed of a single color.

It is a conceptual diagram which shows the structure of the measuring device which concerns on this invention. It is a conceptual diagram which performs a measurement using the measuring device which concerns on this invention. (A) is an image obtained by the wavelength of B, (b) is an image obtained by the wavelength of G, and (c) is an image obtained by the wavelength of R. It is the top view which showed the pixel area of the image sensor. (A) is a graph showing the relationship between the received light intensity and the relative height Z in the left-right direction with respect to the reference dot 7c, and (b) is the relative height in the left-right direction with respect to the differential signal and the reference dot 7c on the horizontal axis. 3 is a graph showing a relationship with Z. (A) is a plan view showing a multi-dot pattern, (b) is a plan view showing a lattice pattern, and (c) is a plan view showing a fringe pattern. It is a flowchart at the time of performing three-dimensional shape measurement using the measuring device concerning the present invention. It is the conceptual diagram which showed the conventional measuring apparatus which performs height measurement using a chromatic aberration.

Explanation of symbols

1 Measuring device 7c Reference dot (predetermined reference position)
8 Test object 11 Coloring lens (imaging lens system)
11a Zooming drive device (zoom lens drive unit)
11c Autofocus drive device (autofocus lens drive unit)
11d Autofocus control unit 20 Image sensor 21 Pixel area (pixel)
30 arithmetic processing unit

Claims (4)

An image sensor having a plurality of pixels arranged in a plane;
An imaging lens system that makes light from the surface of the test object incident and forms an image of the surface of the test object on the image sensor;
It is possible to enlarge or reduce the size of the image formed on the image sensor by moving at least a part of the lenses constituting the imaging lens system in the optical axis direction with respect to the test object. A zoom lens drive,
The light received by each of the plurality of pixels constituting the image sensor in a state where an image of the surface of the test object is formed on the image sensor by being enlarged or reduced by the zoom lens driving unit. An arithmetic processing unit that calculates the relative position of the surface of the test object in the optical axis direction based on the intensity and measures the three-dimensional shape of the test object;
The plurality of pixels receive light from the surface of the test object divided into at least two wavelengths and detect received light intensity for each wavelength,
The arithmetic processing unit is configured to detect the difference between the received light intensity of two wavelengths at a predetermined reference position in the image of the surface of the test object and the two wavelengths of the two wavelengths at other positions in the image of the surface of the test object. A measuring apparatus that measures the three-dimensional shape of the surface of the test object by determining the distance of the other position with respect to the predetermined reference position from the relationship with the difference in received light intensity. An autofocus lens driving unit capable of moving at least a part of the lenses constituting the imaging lens system in the optical axis direction with respect to the object;
The optical axis direction of the at least some lenses by the autofocus lens driving unit so that the image sensor system focuses the image of the predetermined reference position on the object to be focused on the image sensor. The measuring apparatus according to claim 1, further comprising an autofocus control unit that controls movement to the position.   The measuring apparatus according to claim 1, wherein the predetermined reference position on the surface of the test object is a position on the optical axis of the imaging lens system on the surface of the test object. An image sensor having a plurality of pixels arranged in a plane, and an imaging lens system that forms an image of the surface of the test object on the image sensor by making light from the surface of the test object incident; It is possible to enlarge or reduce the size of the image formed on the image sensor by moving at least a part of the lenses constituting the imaging lens system in the optical axis direction with respect to the test object. The plurality of pixels constituting the image sensor in a state where a zoom lens driving unit and an image of the surface of the test object are formed on the image sensor by being enlarged or reduced by the zoom lens driving unit A measurement device comprising: an arithmetic processing unit that calculates a relative position in the optical axis direction of the surface of the test object based on the intensity of light received by each of the test objects and measures a three-dimensional shape of the test object Using A measurement method,
The zoom lens driving unit moves the at least a part of the lenses constituting the imaging lens system with respect to the test object to enlarge or reduce the size of the image formed on the image sensor. A zooming step, a received light intensity detecting step in which the plurality of pixels receive light from the surface of the test object divided into at least two wavelengths and detect the received light intensity for each wavelength; and the arithmetic processing unit detects the light From the relationship between the difference in the received light intensity of two wavelengths at a predetermined reference position in the image of the surface of the object and the difference in the received light intensity of the two wavelengths at other positions in the image of the surface of the test object And a measurement step of measuring a three-dimensional shape of the surface of the test object by obtaining a distance of the other position with respect to the predetermined reference position.

Images