JP2020046381A - Measuring apparatus, laser marking device and measuring method - Google Patents

Abstract

To accurately measure a position of a target while reducing data volume of image processing.SOLUTION: A measuring apparatus includes: a first irradiation section for irradiating a target with a first laser beam: an imaging section for imaging a first luminescent spot to be a luminescent spot of the first laser beam on the target and generating a first image including the first luminescent spot; a first imaging setting section for performing first imaging setting so that a pixel value of a first target pixel to be a pixel satisfying a predetermined condition out of a plurality of pixels constituting the first luminescent spot is included in a predetermined range; a region setting section for setting a first region including the first luminescent spot in a part of a first set image on the basis of the first target pixel included in the first set image to be the first image to which the first imaging setting is applied; a processing section for processing a first partial image to be the first image included in the first region; and a measurement section for measuring a position of the target on the basis of the processed first partial image.SELECTED DRAWING: Figure 1

Description

  One embodiment of the present invention relates to a measurement device or the like for measuring a position of an object using laser light.

  There is a method of measuring the height or the like of an object using laser light. Such a measuring method is disclosed, for example, in Patent Documents 1 and 2.

JP 2016-36841 A JP 2014-134475 A

  In the laser marker described in Patent Literature 1, a working distance, which is the distance between the lower surface of the housing of the laser marker and the surface of the work to be printed, is measured. Specifically, the pointer light is emitted toward the surface of the work, and the bright spot generated on the surface of the work is imaged from a direction different from that of the pointer light. Since the position of the bright spot in the captured image changes according to the working distance, the working distance is obtained based on the position of the bright spot in the image using the principle of triangulation.

  In order to improve the measurement accuracy of a measurement target such as a working distance, it is required to improve the measurement accuracy of the position of a bright spot in an image. However, the reflectivity of laser light often changes according to the material of the work, and in such a case, the brightness of the luminescent spot changes according to the material of the work, and the position detection error may increase. is there. Therefore, for the purpose of suppressing the measurement error based on the change in the brightness of the bright spot, image processing or adjustment of the imaging setting is performed. However, image processing has a large processing load and a long processing time, and thus it is required to reduce the data amount of the image processing.

  The present invention employs the following means in order to solve the above-described problems and the like. In the following description, reference numerals and the like in the drawings are added in parentheses to facilitate understanding of the invention, but each component of the present invention is not limited to these additions, and the present invention is not limited thereto. It should be widely interpreted to a technically understandable range by a trader.

One means of the present invention is:
A first irradiator (11A) for irradiating the object (33) with the first laser beam (LA);
An imaging unit configured to capture an image of a first luminescent spot (SA) that is a luminescent spot of the first laser light on the object and generate a first image (IA) including the first luminescent spot; When,
The first target pixel (PEA), which is a pixel satisfying a predetermined condition (CMA), among a plurality of pixels constituting the first luminescent spot, is included in a first range (MaxA) so as to be included in the first range. A first imaging setting unit (21) configured to perform imaging setting of:
A region including a part of the first image and including the first luminescent spot, based on the first target pixel included in the first image on which the first imaging setting is performed; An area setting unit (22) for setting one area (RA);
A processing unit (24) that processes a first partial image (PIA) that is an image included in the first area;
A measurement unit (25) that measures the position of the object based on the processed first partial image.
It is a measuring device (1).

  According to the measuring device having the above-described configuration, for example, the first imaging setting is performed such that the pixel value of the first target pixel having the largest pixel value is included in the predetermined range. Pixel values of a plurality of pixels forming a point can be kept within a certain range. With this, even when the material of the target object changes and the brightness of the first luminescent spot changes, the image of the first luminescent spot can be drawn well in the image. Can be set appropriately. Since the first partial image included in the first area is processed by the processing unit, the data amount of the image processing can be reduced, so that the processing load can be reduced and the processing time can be shortened. it can. Further, for example, by performing image processing for accurately measuring the position of a bright spot in an image on the first partial image, the position of the first bright spot in the image can be accurately measured. Thereby, the measurement accuracy of the position of the object can be improved.

In the above measuring device, preferably,
The imaging unit captures the first luminescent spot to generate the first partial image,
A second imaging setting unit (23) configured to perform a second imaging setting such that a statistical value of a pixel value of a pixel included in the first partial image is included in a predetermined range (AveA);
The processing unit processes the first partial image on which the second imaging setting has been performed.

  According to the measuring device having the above configuration, for example, the imaging range of the imaging unit can be reduced to a range corresponding to the first region, so that the time required for generating the first partial image in the imaging unit is reduced. Can be. Further, the second imaging setting is performed so that the statistic of the pixel value of the pixel included in the first partial image is included in a predetermined range, so that the outline of the first luminescent spot in the first partial image is obtained. The portion can be drawn well. Thereby, for example, even when the material of the target object changes and the brightness of the first bright spot changes, it is possible to suppress the variation in the shape of the image of the first bright spot in the first partial image. it can.

In the above measuring device, preferably,
The measurement unit measures the position of the object based on the position (CA) of the center of gravity of the pixel included in the processed first partial image.

  According to the measuring device having the above configuration, the pixel having a small pixel value located around the first luminescent point in the first partial image has almost no influence on the position of the center of gravity. The position of the center of gravity can be determined based on the distribution of the pixel values of the constituent pixels. Thereby, for example, even when the image of the first luminescent spot is deviated from the center of the first partial image, the position of the first luminescent spot can be correctly calculated. Can be improved.

In the above measuring device, preferably,
The predetermined condition is to have a maximum pixel value in the detection range.

  According to the measuring device having the above configuration, the maximum value of the pixel values of the plurality of pixels constituting the first bright spot in the image can be kept within a predetermined range. Generation can be suppressed.

In the above measuring device, preferably,
The processing unit performs at least one of a binarization process, a contraction process, and an expansion process on the first partial image.

  According to the measuring device having the above configuration, by performing image processing for accurately measuring the position of the bright spot in the image, for example, noise of laser light, and the shape of the bright spot that changes depending on the material of the target object, etc. The calculation error of the position of the center of gravity based on this can be suppressed.

In the above measuring device, preferably,
The first imaging setting is to set an exposure time in the imaging unit.

  According to the measuring device having the above configuration, for example, the pixel value of the first target pixel is included in the predetermined range as compared with the case where the intensity of the first laser light is adjusted or the filter is inserted into the first laser light. The first imaging setting can be easily realized.

In the above measuring device, preferably,
The second imaging setting is to set an exposure time in the imaging unit.

  According to the measuring device having the above-described configuration, for example, compared with adjustment of the intensity of the first laser light, insertion of a filter into the first laser light, or the like, statistics of the pixel values of the pixels included in the first partial image are obtained. The second imaging setting in which the value is included in the predetermined range can be easily realized.

In the above measuring device, preferably,
A second irradiation unit (11B) that irradiates the object with a second laser beam (LB);
The imaging unit captures a second bright spot (SB), which is a bright spot of the second laser light, on the object, and further generates a second image (IB) including the second bright spot. And
The first imaging setting unit sets a pixel value of a second target pixel (PEB), which is a pixel satisfying a predetermined condition (CMB), among a plurality of pixels forming the second bright spot in a predetermined range ( Max B) is further set so as to be included in MaxB).
The area setting unit is an area including a part of the second image based on the second target pixel included in the second image on which the third imaging setting is performed, and And further setting a second region (RB) including a bright spot of
The processing unit further processes a second partial image (PIB) that is an image included in the second area,
The measuring unit measures the position of the object based on the processed first partial image and the processed second partial image.

  According to the measuring device having the above configuration, for example, even when the reflectance of the laser light near the first luminescent spot is different from the reflectance of the laser light near the second luminescent spot, the first luminescent spot in the image is different. And the position of the second bright spot in the image can be measured with high accuracy. Thus, for example, in a configuration in which two laser beams are irradiated on the object and the position of the object is measured based on the distance between the first luminescent spot and the second luminescent spot in the image, the position of the object is determined. Measurement accuracy can be improved.

Another means of the present invention is:
Any one of the above measuring devices (1);
A marking unit (32) for performing laser marking on the target object based on the result measured by the measurement device,
It is a laser marking device.

  According to the laser marking device having the above configuration, for example, the first imaging setting is performed such that the pixel value of the first target pixel having the largest pixel value is included in the predetermined range. The pixel values of a plurality of pixels forming the bright spot can be kept within a certain range. With this, even when the material of the target object changes and the brightness of the first luminescent spot changes, the image of the first luminescent spot can be drawn well in the image. Can be set appropriately. Since the first partial image included in the first area is processed by the processing unit, the data amount of the image processing can be reduced, so that the processing load can be reduced and the processing time can be shortened. it can. Further, for example, by performing image processing for accurately measuring the position of a bright spot in an image on the first partial image, the position of the first bright spot in the image can be accurately measured. As a result, the measurement accuracy of the position of the target object can be improved. For example, even when the target object has a step, the focusing position of the laser beam for laser marking is correctly adjusted based on the measurement result. Thus, a good marking pattern can be formed.

Another means of the present invention is:
A measurement method in a measurement device including a first irradiation unit that irradiates a first laser beam to an object,
Imaging a first luminescent spot, which is a luminescent spot of the first laser light, on the object, and generating a first image including the first luminescent spot;
Performing a first imaging setting so that a pixel value of a first target pixel that is a pixel satisfying a predetermined condition among a plurality of pixels forming the first bright spot is included in a predetermined range;
A region including a part of the first image and including the first luminescent spot, based on the first target pixel included in the first image on which the first imaging setting is performed; Setting an area 1;
Processing a first partial image that is an image included in the first area;
Measuring the position of the object based on the processed first partial image,
It is a measuring method.

  According to the measurement method having the above-described configuration, for example, the first imaging setting is performed so that the pixel value of the first target pixel having the largest pixel value is included in the predetermined range, so that the first brightness in the image is set. Pixel values of a plurality of pixels forming a point can be kept within a certain range. With this, even when the material of the target object changes and the brightness of the first luminescent spot changes, the image of the first luminescent spot can be drawn well in the image. Can be set appropriately. Since the first partial image included in the first area is processed by the processing unit, the data amount of the image processing can be reduced, so that the processing load can be reduced and the processing time can be shortened. it can. Further, for example, by performing image processing for accurately measuring the position of a bright spot in an image on the first partial image, the position of the first bright spot in the image can be accurately measured. Thereby, the measurement accuracy of the position of the object can be improved.

FIG. 1 is a diagram illustrating a configuration of a laser marking device according to the present embodiment. FIG. 2 is a diagram illustrating an example of a first image generated by the camera according to the present embodiment. FIG. 3 is a diagram illustrating an example of a second image generated by the camera according to the present embodiment. FIG. 4 is a diagram illustrating a configuration of an image analysis unit in the measurement device of the present embodiment. FIG. 5 is a diagram illustrating an example of a first setting image generated by the camera according to the present embodiment. FIG. 6 is a diagram illustrating an example of the second setting image generated by the camera according to the present embodiment. FIG. 7 is a diagram illustrating an example of a first partial image generated by the camera according to the present embodiment. FIG. 8 is a diagram illustrating an example of the second partial image generated by the camera according to the present embodiment. FIG. 9 is a diagram illustrating an example of a first partial image processed by the processing unit according to the present embodiment. FIG. 10 is a diagram illustrating an example of the second partial image processed by the processing unit according to the present embodiment. FIG. 11 is a diagram illustrating an example of an image including the center of gravity obtained by the measurement unit according to the present embodiment. FIG. 12 is a flowchart illustrating a marking process in the laser marking device of the present embodiment. FIG. 13 is a flowchart illustrating a coordinate calculation process of the image ISA in the laser marking device of the present embodiment. FIG. 14 is a flowchart illustrating a coordinate calculation process of the image ISB in the laser marking device of the present embodiment.

  The laser marking device of the present invention irradiates a target with laser light, and captures a bright spot of the laser light on the target to generate an image. In addition, an area including the luminescent spot is set, a first partial image which is an image included in the set area is processed, and the position of the object is measured based on the processed partial image. And one of them.

An embodiment according to the present invention will be described according to the following configuration. However, the embodiments described below are merely examples of the present invention, and do not limit the technical scope of the present invention. In the drawings, the same components are denoted by the same reference numerals, and description thereof may be omitted.
1. 1. Embodiment (1) Configuration Example of Laser Marking Apparatus (2) Operation Example 2. Features of the present invention Supplementary information

<1. Embodiment>
<(1) Configuration example of laser marking device>
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a laser marking device according to the present embodiment. As shown in FIG. 1, a laser marking device 31 of the present embodiment includes a measuring device 1 and a marking unit 32. The measurement device 1 includes a laser light source 11A, a laser light source 11B, a camera 12, an image analysis unit 13, and a control unit 14.

  In the present embodiment, the laser marking device 31 performs marking on the target 33 using laser light of a marking laser (not shown). Specifically, when performing laser marking, marking is performed on the target 33 by condensing a laser for marking on the surface of the target 33. For example, when there is no step on the surface of the marking object, the distance between the marking laser and the surface can be easily kept constant during marking. That is, while the marking is being performed, the marking laser is focused on the surface, so that good marking is performed.

  As shown in FIG. 1, when there is a step on the surface of the target 33, the distance between the marking laser and the surface of the target 33 (hereinafter, sometimes referred to as a measurement target surface 33 </ b> A) ( Hereinafter, it may be referred to as a work distance.). Therefore, measurement of the position of the measurement target surface 33A is required in order to focus the marking laser on the measurement target surface 33A. Even when the marking target 33 has no step, for example, when the height of the target 33 varies, the work distance may change. Desired. Here, the target object 33 is, for example, a product having a step on its surface, and is stamped with an identifier for ensuring traceability, such as a micro QR code and a logo.

<Laser light sources 11A and 11B>
The laser light source 11A irradiates the object 33 with the laser light LA. The laser light source 11B irradiates the object 33 with the laser light LB. In the present embodiment, characteristics such as the wavelength, the beam diameter, the beam cross-sectional shape, and the intensity of the laser light LA and the laser light LB are substantially the same. The laser light sources 11A and 11B are fixed by a holding unit (not shown) so that a surface having the laser light LA as a normal line and a surface having the laser light LB as a normal line are non-parallel. The laser light sources 11A and 11B are specific examples of the “first irradiation unit” and the “second irradiation unit” in the present invention, respectively. The laser beams LA and LB are specific examples of the “first laser beam” and the “second laser beam” in the present invention, respectively.

  In the present embodiment, the laser light sources 11A and 11B are, for example, semiconductor lasers, and are provided so that the laser lights LA and LB can intersect at points. Here, “the laser beams LA and LB may intersect at a point” means that the laser beam LA and the laser beam LB may intersect at one point when the object 33 is not provided. Specifically, the laser beams LA and LB intersect at the intersection CS at an angle γ when the target 33 is not provided. A plane that is orthogonal to the bisector Bis bisecting the angle γ and that includes the intersection point CS is defined as a “specular reflection surface MRS”. The laser light sources 11A and 11B may be other types of lasers than the semiconductor laser.

  Hereinafter, the laser light sources 11A and 11B sides with respect to the regular reflection surface MRS may be referred to as “light source sides”. The opposite sides of the laser light sources 11A and 11B with respect to the regular reflection surface MRS may be referred to as "non-light source side". The measurement target surface 33A of the target 33 is substantially parallel to the regular reflection surface MRS. Bright points SA and SB are generated on the measurement target surface 33A by the laser beams LA and LB, respectively. The bright points SA and SB are specific examples of the “first bright point” and the “second bright point” in the present invention, respectively.

<Control unit 14>
The control unit 14 irradiates the laser light sources 11A and 11B with the laser beams LA and LB one by one at a different timing. In the present embodiment, for example, when receiving the measurement command from the marking unit 32, the control unit 14 sets a period PA and a period PB that do not overlap each other. In the period PA, the control unit 14 turns on the laser light source 11A, irradiates the laser light LA to the measurement target surface 33A, turns off the laser light source 11B, and outputs on information SA to the image analysis unit 13. In the period PB, the control unit 14 turns off the laser light source 11A, turns on the laser light source 11B, irradiates the laser light LB to the measurement target surface 33A, and outputs on information SB to the image analysis unit 13.

<Camera 12>
FIG. 2 is a diagram illustrating an example of a first image generated by the camera according to the present embodiment. FIG. 3 is a diagram illustrating an example of a second image generated by the camera according to the present embodiment. 2 and 3 show images in the case where the position of the measurement target surface 33A is a position separated from the specular reflection surface MRS by the distance Dv toward the light source.

  As shown in FIGS. 1 to 3, the camera 12 is provided on the light source side such that the optical axis of the lens substantially matches the bisector Bis. The camera 12 has, for example, a telecentric optical system, and the photographable range FR does not change depending on the distance from the camera 12. The measurable range MR is a range in which the bright points SA and SB fall within the photographable range FR on the light source side.

  The camera 12 operates under the control of the image analysis unit 13 and captures an image of the measurement target surface 33A so as to include the bright spot SA or the bright spot SB. In the present embodiment, the camera 12 has an image sensor capable of capturing a black and white image, for example. Note that a sensor capable of capturing a color image may be used as the image sensor. The camera 12 receives an imaging command from the image analysis unit 13 during the period PA. The imaging instruction includes, for example, an imaging region and an exposure time. When the camera 12 receives the imaging instruction, the camera 12 captures an image in the imaging region and the exposure time included in the imaging instruction. For example, when the imaging region is the entire range, the camera 12 captures an image of the bright spot SA on the measurement target surface 33A at the exposure time using the entire surface of the light receiving element, and based on the captured result, an image ISA of the bright spot SA. Is generated (hereinafter, may be referred to as an image IA) (see FIG. 2).

  Further, the camera 12 receives an imaging command from the image analysis unit 13 during the period PB. When the camera 12 receives the imaging command, if the imaging region included in the imaging command is, for example, the entire range, the camera 12 uses the entire surface of the light receiving element to set the bright spot SB on the measurement target surface 33A with the exposure time included in the imaging command. The image is captured, and an image (hereinafter, sometimes referred to as an image IB) including the image ISB of the bright spot SB is generated based on the imaging result (see FIG. 3). The image generated by the camera 12 includes a plurality of pixels. The pixel value of the pixel is, for example, any one of 0 to 255. That is, the camera 12 generates an image of 256 gradations. The camera 12 outputs image information including the generated image to the image analysis unit 13.

<Image analysis unit 13>
FIG. 4 is a diagram illustrating a configuration of an image analysis unit in the measurement device of the present embodiment. As shown in FIG. 4, the image analysis unit 13 of the present embodiment includes an entire image adjustment unit 21, an area setting unit 22, a partial image adjustment unit 23, a processing unit 24, and a measurement unit 25.

<Overall image adjustment unit 21>
<Processing of Image IA>
As shown in FIGS. 2 and 4, the whole image adjustment unit 21 determines a pixel value of a first target pixel which is a pixel satisfying a predetermined condition CMA among a plurality of pixels constituting the image ISA of the bright spot SA. Are set to be included in the predetermined range MaxA. Here, the condition CMA is, for example, to have a maximum pixel value in the entire image IA as a detection range. The first imaging setting is, for example, to set an exposure time in the camera 12. Range MaxA is, for example, a range of 50 to 250. The whole image adjustment unit 21 is a specific example of the “first imaging setting unit” in the present invention.

  Specifically, when the entire image adjustment unit 21 receives the ON information SA from the control unit 14, for example, the entire image adjustment unit 21 outputs an imaging command including the entire range and the initial value ETA to the camera 12 as the imaging region and the exposure time, respectively. Initially, the imaging area and exposure time of the camera 12 are set. The whole image adjustment unit 21 acquires image information from the camera 12 as a response to the imaging command, and, based on the acquired image information, a first target pixel (hereinafter, referred to as a first target pixel having a maximum pixel value from a plurality of pixels included in the image IA) , Maximum pixel PEA).

  For example, when the pixel value of the maximum pixel PEA is included in the range MaxA, the entire image adjustment unit 21 may use the image IA on which the first imaging setting is performed (hereinafter, may be referred to as a first setting image). The included image information is output to the region setting unit 22 and the first imaging setting ends.

  On the other hand, when the pixel value of the maximum pixel PEA is not included in the range MaxA, the entire image adjustment unit 21 changes the exposure time of the camera 12 so that the pixel value of the maximum pixel PEA is included in the range MaxA. Specifically, for example, when the pixel value of the maximum pixel PEA is larger than the range MaxA in a case where the reflectance near the luminescent spot SA on the measurement target surface 33A is large, for example, To a shorter time. When the pixel value of the maximum pixel PEA is smaller than the range MaxA, for example, in a case where the reflectance near the luminescent spot SA on the measurement target surface 33A is small, the overall image adjustment unit 21 sets the exposure time of the camera 12 to be longer. Change to time. When the exposure time of the camera 12 is changed and the pixel value of the maximum pixel PEA is included in the range MaxA, the whole image adjustment unit 21 outputs image information including the first setting image to the region setting unit 22. Then, the first imaging setting ends.

  Although the condition CMA is described as having the largest pixel value in the entire image IA, the condition CMA is described as having the second largest pixel value in the entire image IA or the third condition in the entire image IA. It may have a large pixel value. Although the detection range of the condition CMA has been described as being the entire image IA, the detection range may be a part of the image IA, for example, a range where the image ISA can exist. Also, it has been described that the first imaging setting is to set the exposure time in the camera 12, but the first imaging setting is to set the intensity of the laser beam LA or to set the filter on or off. May be performed.

<Process of Image IB>
As shown in FIGS. 3 and 4, the whole image adjustment unit 21 determines a pixel value of a second target pixel which is a pixel satisfying a predetermined condition CMB among a plurality of pixels constituting the image ISB of the bright spot SB. Are further set so that is included in the predetermined range MaxB. In the present embodiment, the condition CMB is the same as the condition CMA, and has a maximum pixel value in the entire image IB as a detection range. The third imaging setting is the same as the first imaging setting, and is to set an exposure time in the camera 12. The range MaxB is the same as the range MaxA, and is in the range of 50 to 250. Note that the condition CMB may be different from the condition CMA. The third imaging setting may be different from the first imaging setting. The range MaxB may be different from the range MaxA.

  Specifically, upon receiving the ON information SB from the control unit 14, the overall image adjustment unit 21 outputs, to the camera 12, for example, an imaging command including the entire range and the initial value ETB as the imaging region and the exposure time, respectively. Initially, the imaging area and exposure time of the camera 12 are set. Here, the initial value ETB is the same as the initial value ETA. Note that the initial value ETB may be different from the initial value ETA. The whole image adjustment unit 21 acquires image information from the camera 12 as a response to the imaging command, and, based on the acquired image information, a second target pixel (hereinafter, referred to as a second target pixel) having a maximum pixel value from a plurality of pixels included in the image IB. , May be referred to as a maximum pixel PEB).

  For example, when the pixel value of the maximum pixel PEB is included in the range MaxB, the entire image adjustment unit 21 may use the image IB on which the third imaging setting has been performed (hereinafter, may be referred to as a second setting image). The image information including the image information is output to the area setting unit 22 and the third imaging setting ends.

  On the other hand, when the pixel value of the maximum pixel PEB is not included in the range MaxB, the overall image adjustment unit 21 changes the exposure time of the camera 12 so that the pixel value of the maximum pixel PEB is included in the range MaxB. More specifically, if the pixel value of the maximum pixel PEB is larger than the range MaxB, for example, when the reflectance near the bright spot SB on the measurement target surface 33A is large, To a shorter time. When the pixel value of the maximum pixel PEB is smaller than the range MaxB, for example, in a case where the reflectance near the bright spot SB on the measurement target surface 33A is small, the overall image adjustment unit 21 sets the exposure time of the camera 12 to be longer. Change to time. The whole image adjustment unit 21 outputs image information including the second setting image to the region setting unit 22 when the exposure time of the camera 12 is changed so that the pixel value of the maximum pixel PEB is included in the range MaxB. Then, the third imaging setting ends.

  Although the condition CMB has been described as having the largest pixel value in the entire image IB, the condition CMB has the second largest pixel value in the entire image IB, or the third condition in the entire image IB. It may have a large pixel value. Although the detection range of the condition CMB has been described as being the entire image IB, the detection range may be a part of the image IB, for example, a range where the image ISB can exist. Although the third imaging setting is described as setting the exposure time in the camera 12, the third imaging setting is to set the intensity of the laser beam LB or to set the filter on or off. May be performed.

<Area setting unit 22>
<Processing of Image IA>
FIG. 5 is a diagram illustrating an example of a first setting image generated by the camera according to the present embodiment. As shown in FIGS. 4 and 5, the area setting unit 22 is an area including a part of the image IA and includes the image ISA of the bright spot SA based on the maximum pixel PEA included in the first setting image. The area RA is set. Specifically, when the area setting unit 22 receives image information including the first setting image from the whole image adjustment unit 21, the area setting unit 22 acquires the coordinates of the maximum pixel PEA based on the image information. The coordinates are, for example, coordinates in a pixel unit having the origin at the upper left corner of the four corners of the image IA (hereinafter, may be referred to as whole image coordinates). The region setting unit 22 sets the region RA so as to include the maximum pixel PEA based on the acquired whole image coordinates. Specifically, the region setting unit 22 sets, for example, a rectangular region RA having a predetermined size around the maximum pixel PEA. The region setting unit 22 outputs, for example, first region information including the entire image coordinates of the four corners of the set region RA to the partial image adjustment unit 23. Although the configuration in which the area RA has a predetermined size has been described, the size of the area RA may be changed according to the size of the image of the bright spot SA. Further, although the configuration in which the maximum pixel PEA is located at the center of the area RA has been described, a configuration in which the maximum pixel PEA is located off the center of the area RA may be employed. The area RA is a specific example of the “first area” in the present invention.

<Process of Image IB>
FIG. 6 is a diagram illustrating an example of the second setting image generated by the camera according to the present embodiment. As shown in FIGS. 4 and 6, the region setting unit 22 is a region including a part of the image IB and including the image ISB of the bright spot SB based on the maximum pixel PEB included in the second setting image. The area RB is further set. Specifically, when the area setting unit 22 receives image information including the second setting image from the entire image adjustment unit 21, the area setting unit 22 acquires the entire image coordinates of the maximum pixel PEB based on the image information. The region setting unit 22 sets the region RB so as to include the maximum pixel PEB based on the acquired whole image coordinates. Specifically, the region setting unit 22 sets, for example, a rectangular region RB having a predetermined size around the maximum pixel PEB. Here, the size and shape of the region RB are the same as the size and shape of the region RA, respectively. Note that the size of the region RB may be different from the size of the region RA. Further, the shape of the region RB may be different from the shape of the region RA. The region setting unit 22 outputs, to the partial image adjustment unit 23, second region information including the entire image coordinates of the four corners of the set region RB, for example. Although the configuration in which the region RB has a predetermined size has been described, the size of the region RB may be changed according to the size of the image of the bright spot SB. Further, the configuration in which the maximum pixel PEB is located at the center of the region RB has been described. However, the configuration may be such that the maximum pixel PEB is located at a position shifted from the center of the region RB. The region RB is a specific example of the “second region” in the present invention.

<Partial image adjustment unit 23>
<Processing of Image IA>
FIG. 7 is a diagram illustrating an example of a first partial image generated by the camera according to the present embodiment. As shown in FIGS. 4 and 7, the partial image adjustment unit 23 is a pixel of a pixel included in a first partial image (hereinafter, sometimes referred to as a partial image PIA) which is an image included in the area RA. The second imaging setting is performed so that the statistical value is included in a predetermined range. In the present embodiment, the partial image adjustment unit 23 performs the second imaging setting so that the average value of the pixel values of the pixels included in the partial image PIA is included in the range AveA. Here, the second imaging setting is to set, for example, an exposure time in the camera 12. The range AveA is, for example, a range of 15 to 35. The partial image adjustment unit 23 is a specific example of the “second imaging setting unit” in the present invention.

  More specifically, upon receiving the first region information from the region setting unit 22, the partial image adjustment unit 23 issues, for example, an imaging command including the first region information and the initial value ETRA as the imaging region and the exposure time, respectively, to the camera 12. Output to Upon receiving the imaging command, the camera 12 specifies a light receiving element portion corresponding to the area RA based on the first area information. Then, the camera 12 captures an image with the exposure time included in the capturing instruction using the relevant portion of the light receiving element, and generates a partial image PIA including the image ISA of the bright spot SA (see FIG. 7). The camera 12 outputs image information including the generated partial image PIA to the partial image adjustment unit 23.

  When receiving the image information from the camera 12, the partial image adjustment unit 23 calculates an average value of the pixel values of a plurality of pixels included in the partial image PIA based on the image information. When the calculated average value is included in the range AveA, the partial image adjustment unit 23 outputs the first partial image information including the partial image PIA to the processing unit 24 and outputs the first area information to the measurement unit 25. Then, the second imaging setting ends.

  On the other hand, when the average value is not included in the range AveA, the partial image adjustment unit 23 changes the exposure time of the camera 12 so that the average value is included in the range AveA. Specifically, when the average value is larger than the range AveA, for example, in a case where the reflectance near the luminescent spot SA on the measurement target surface 33A is large, the partial image adjustment unit 23 sets the exposure time of the camera 12 to a shorter time. Change to Further, the partial image adjustment unit 23 changes the exposure time of the camera 12 to a longer time when the average value is smaller than the range AveA, for example, in a case where the reflectance near the bright point SA on the measurement target surface 33A is small. . When the exposure time of the camera 12 is changed and the average value is included in the range AveA, the partial image adjustment unit 23 outputs the first partial image information including the partial image PIA to the processing unit 24 and The first area information is output to the measurement unit 25, and the second imaging setting ends.

  The configuration in which the partial image adjustment unit 23 calculates the average value of the pixel values of the pixels included in the partial image PIA as the statistic has been described. However, the partial image adjustment unit 23 includes, for example, the pixel included in the partial image PIA. The median value or the mode value of the pixel values may be calculated as a statistical value. Also, the second imaging setting is described as setting the exposure time in the camera 12, but the second imaging setting is to set the intensity of the laser beam LA or to set the filter on or off. May be performed.

<Process of Image IB>
FIG. 8 is a diagram illustrating an example of the second partial image generated by the camera according to the present embodiment. As shown in FIGS. 4 and 8, the partial image adjustment unit 23 is a pixel included in a second partial image (hereinafter, sometimes referred to as a partial image PIB) which is an image included in the region RB. The fourth imaging setting is further performed so that the statistical value is included in the predetermined range. In the present embodiment, the partial image adjustment unit 23 performs the fourth imaging setting so that the average value of the pixel values of the pixels included in the partial image PIB is included in the range AveB. The fourth imaging setting is the same as the second imaging setting, and is to set an exposure time in the camera 12. The range AveB is the same as the range AveA and ranges from 15 to 35. Note that the fourth imaging setting may be different from the second imaging setting. Range AveB may be different from range AveA.

  Specifically, when the partial image adjustment unit 23 receives the second region information from the region setting unit 22, the partial image adjustment unit 23 issues, for example, an imaging command including the second region information and the initial value ETRB as the imaging region and the exposure time, respectively, to the camera 12. Output to Here, the initial value ETRB is the same as the initial value ETRA. Note that the initial value ETRB may be different from the initial value ETRA. Upon receiving the imaging command, the camera 12 specifies a portion of the light receiving element corresponding to the area RB based on the second area information. Then, the camera 12 captures an image using the relevant portion of the light receiving element for the exposure time included in the capturing instruction, and generates a partial image PIB including the image ISB of the bright spot SB (see FIG. 8). The camera 12 outputs image information including the generated partial image PIB to the partial image adjustment unit 23.

  Upon receiving the image information from the camera 12, the partial image adjustment unit 23 calculates an average value of the pixel values of a plurality of pixels included in the partial image PIB based on the image information. When the calculated average value is included in the range AveB, the partial image adjustment unit 23 outputs the second partial image information including the partial image PIB to the processing unit 24 and outputs the second area information to the measurement unit 25. Then, the fourth imaging setting ends.

  On the other hand, when the average value is not included in the range AveB, the partial image adjustment unit 23 changes the exposure time of the camera 12 so that the average value is included in the range AveB. Specifically, for example, in a case where the reflectance near the luminescent spot SB on the measurement target surface 33A is large and the average value is larger than the range AveB, the partial image adjustment unit 23 shortens the exposure time of the camera 12 for a shorter time. Change to Also, the partial image adjustment unit 23 changes the exposure time of the camera 12 to a longer time when the average value is smaller than the range AveB, for example, in a case where the reflectance near the bright spot SB on the measurement target surface 33A is small. . When the exposure time of the camera 12 is changed and the average value is included in the range AveB, the partial image adjustment unit 23 outputs the second partial image information including the partial image PIB to the processing unit 24 and The second area information is output to the measurement unit 25, and the fourth imaging setting ends.

  Although the configuration in which the partial image adjustment unit 23 calculates the average value of the pixel values of the pixels included in the partial image PIB as the statistical value has been described, for example, the partial image adjustment unit 23 may calculate the pixel value included in the partial image PIB. The median value or the mode value of the pixel values may be calculated as a statistical value. Also, the fourth imaging setting has been described as setting the exposure time in the camera 12, but the fourth imaging setting is to set the intensity of the laser beam LB or to set the filter on or off. May be performed.

<Processing unit 24>
<Processing of partial image PIA>
FIG. 9 is a diagram illustrating an example of a first partial image processed by the processing unit according to the present embodiment. As shown in FIGS. 4 and 9, the processing unit 24 processes the partial image PIA on which the second imaging setting has been performed. In the present embodiment, the processing unit 24 performs a binarization process, a contraction process, and an expansion process on the partial image PIA.

  Specifically, when the processing unit 24 receives the first partial image information from the partial image adjustment unit 23, the processing unit 24 performs a binarization process on the partial image PIA included in the first partial image information, and Is converted into an image composed of two colors, white and black. Specifically, the processing unit 24 sequentially selects the pixels included in the partial image PIA, and determines whether the pixel value of the selected pixel is larger than a predetermined threshold ThA. When the pixel value of the selected pixel is larger than the threshold ThA, the processing unit 24 sets the pixel value to the value VW. On the other hand, when the pixel value of the selected pixel is equal to or smaller than the threshold ThA, the processing unit 24 sets the pixel value to a value VB smaller than the value VW. In this manner, in the partial image PIA, pixels having a pixel value larger than the threshold value ThA, such as pixels constituting the image ISA, show white based on the value VW. Further, for example, a pixel having a pixel value equal to or smaller than the threshold value ThA, such as a pixel constituting the periphery of the image ISA, shows black based on the value VB.

  The processing unit 24 performs contraction processing on the partial image PIA that has been subjected to the binarization processing. Specifically, for example, the processing unit 24 sequentially selects the pixels included in the partial image PIA, and when the pixel value of at least one of the peripheral pixels of the selected pixel is the value VB. , The pixel value of the selected pixel is set to the value VB.

  The processing unit 24 performs an expansion process on the partial image PIA that has been subjected to the contraction process. Specifically, for example, the processing unit 24 sequentially selects the pixels included in the partial image PIA, and when the pixel value of at least one of the peripheral pixels of the selected pixel is the value VW. , The pixel value of the selected pixel is set to the value VW. As described above, by performing the contraction process and the expansion process on the partial image PIA, image noise based on, for example, noise of the laser beam LA can be removed from the partial image PIA. The processing unit 24 outputs the first processed image information including the partial image PIA that has been subjected to the binarization processing, the contraction processing, and the expansion processing to the measurement unit 25.

<Processing of partial image PIB>
FIG. 10 is a diagram illustrating an example of the second partial image processed by the processing unit according to the present embodiment. As shown in FIGS. 4 and 10, the processing unit 24 processes the partial image PIB on which the fourth imaging setting has been performed. In the present embodiment, the processing unit 24 performs a binarization process, a contraction process, and an expansion process on the partial image PIB.

  Specifically, when the processing unit 24 receives the second partial image information from the partial image adjustment unit 23, the processing unit 24 performs a binarization process on the partial image PIB included in the second partial image information, and performs the partial image PIB Is converted into an image composed of two colors, white and black. Specifically, the processing unit 24 sequentially selects the pixels included in the partial image PIB, and determines whether the pixel value of the selected pixel is larger than a predetermined threshold ThB. Here, the threshold ThB is the same as the threshold ThA. Note that the threshold value ThB may be different from the threshold value ThA. When the pixel value of the selected pixel is larger than the threshold ThA, the processing unit 24 sets the pixel value to the value VW. On the other hand, when the pixel value of the selected pixel is equal to or smaller than the threshold ThB, the processing unit 24 sets the pixel value to the value VB. In this way, in the partial image PIB, for example, a pixel having a pixel value larger than the threshold value ThB, such as a pixel constituting the image ISB, shows white based on the value VW. Further, for example, a pixel having a pixel value equal to or smaller than the threshold value ThB, such as a pixel constituting the periphery of the image ISB, shows black based on the value VB.

  The processing unit 24 performs a contraction process on the partial image PIB that has been subjected to the binarization process. Specifically, for example, the processing unit 24 sequentially selects the pixels included in the partial image PIB, and when the pixel value of at least one of the pixels around the selected pixel is the value VB. , The pixel value of the selected pixel is set to the value VB.

  The processing unit 24 performs an expansion process on the partial image PIB that has been subjected to the contraction process. Specifically, for example, the processing unit 24 sequentially selects the pixels included in the partial image PIB, and when the pixel value of at least one of the peripheral pixels of the selected pixel is the value VW. , The pixel value of the selected pixel is set to the value VW. As described above, by performing the contraction processing and the expansion processing on the partial image PIB, image noise based on, for example, the noise of the laser beam LB can be removed from the partial image PIA. The processing unit 24 outputs the second processed image information including the partial image PIB that has been subjected to the binarization processing, the contraction processing, and the expansion processing to the measurement unit 25.

  Although the configuration in which the processing unit 24 performs the binarization processing, the contraction processing, and the expansion processing in this order has been described, the order of the binarization processing, the contraction processing, and the expansion processing performed by the processing unit 24 may be interchanged.

<Measurement unit 25>
The measurement unit 25 measures the position of the target 33 based on the processed partial image PIA and the processed partial image PIB. In the present embodiment, the measurement unit 25 measures the position of the object 33 based on the position of the center of gravity of the pixels included in the processed partial image PIA and the position of the center of gravity of the pixels included in the processed partial image PIB. I do.

  As shown in FIGS. 4 and 9, when the measurement unit 25 receives the first processed image information from the processing unit 24, based on the received first processed image information, the measurement unit 25 The coordinates of the center of gravity of the pixel of are calculated. Specifically, the measurement unit 25 calculates, for example, the coordinates of a plurality of pixels included in the partial image PIA. These coordinates are, for example, coordinates in pixel units (hereinafter, may be referred to as partial image coordinates) with the origin at the upper left corner of the four corners of the partial image PIA. The measurement unit 25 calculates the partial image coordinates PCA of the center of gravity of the plurality of pixels based on the partial image coordinates of the plurality of pixels included in the partial image PIA, using the pixel values as weights.

  As shown in FIGS. 4 and 10, when the measurement unit 25 receives the second processed image information from the processing unit 24, based on the received second processed image information, the measurement unit 25 The coordinates of the center of gravity of the pixel of are calculated. Specifically, the measurement unit 25 calculates, for example, partial image coordinates of a plurality of pixels included in the partial image PIB. The partial image coordinates in this case are coordinates in pixel units with the origin at the upper left corner of the four corners of the partial image PIB. The measurement unit 25 calculates the partial image coordinates PCB of the center of gravity of the plurality of pixels based on the partial image coordinates of the plurality of pixels included in the partial image PIB, using the pixel values as weights.

  FIG. 11 is a diagram illustrating an example of an image including the center of gravity obtained by the measurement unit according to the present embodiment. As shown in FIG. 11, the measuring unit 25 converts the partial image coordinates PCA into the whole image coordinates CA based on the first area information received from the partial image adjusting unit 23. In addition, the measurement unit 25 converts the partial image coordinates PCB into the whole image coordinates CB based on the second area information received from the partial image adjustment unit 23. Then, the measuring unit 25 calculates the distance IDh between the entire image coordinates CA and the entire image coordinates CB, for example, in pixel units.

  In the present embodiment, for example, the measurement unit 25 holds an approximate expression indicating the relationship between the distance IDh and the distance Dv, and calculates the distance Dv from the distance IDh using the approximate expression. The approximate expression approximates the relationship between the distance IDh and the distance Dv by, for example, a polynomial. Specifically, the measurement target surface 33A located at the distance Dv measured in advance is imaged, and the distance IDh is calculated based on the imaging result. Thereby, a data set of the distance IDh and the distance Dv is obtained. The approximate expression is created based on a plurality of data sets obtained while changing the distance Dv. In this embodiment, the approximate expression is calculated a plurality of times, and the calculation of the approximate expression is performed a plurality of times until the convergence rate of the approximate expression becomes 95% reliability. Note that the measurement unit 25 may use, for example, a table indicating the correspondence between the plurality of distances IDh and the plurality of distances Dv instead of the approximate expression.

  The measurement unit 25 determines whether the measurement target surface 33A is located on the light source side or the non-light source side with respect to the regular reflection surface MRS based on the whole image coordinates CA and the whole image coordinates CB. When the measurement unit 25 determines that the measurement target surface 33A is located on the light source side with respect to the regular reflection surface MRS, the measurement unit 25 determines the position separated from the intersection CS by a distance Dv toward the light source along the bisector Bis to the measurement target surface 33A. Is calculated. On the other hand, when the measurement unit 25 determines that the measurement target surface 33A is located on the non-light source side with respect to the specular reflection surface MRS, the measurement unit 25 determines a position that is a distance Dv away from the intersection CS along the bisector Bis toward the non-light source. It is calculated as the position of the measurement target surface 33A. The measurement unit 25 outputs position information indicating the position of the measurement target surface 33A to the marking unit 32.

<Marking part 32>
As shown in FIG. 1, the marking unit 32 performs laser marking on the measurement target surface 33 </ b> A of the target 33 based on the result measured by the image analysis unit 13 in the measurement device 1. In the present embodiment, for example, the marking unit 32 performs marking in dot units on the measurement target surface 33A. In detail, for example, when marking is performed on the target dot MD on the measurement target surface 33A, the marking unit 32 outputs a measurement command to the control unit 14 and transmits position information that is a result of the measurement command from the image analysis unit 13. receive. The marking unit 32 acquires the work distance based on the received position information, and adjusts the focusing position of the marking laser based on the acquired work distance. The marking section 32 oscillates a marking laser to mark the dots MD.

<(2) Operation example>
<Overall operation of laser marking device>
Next, a marking process in the laser marking device of the present embodiment will be described with reference to FIG. FIG. 12 is a flowchart illustrating a marking process in the laser marking device of the present embodiment.

<S100>
It is assumed that the marking unit 32 outputs a measurement command to the control unit 14 when the marking unit 32 performs marking of the target dot MD. When receiving the measurement command from the marking unit 32, the control unit 14 sets a period PA and a period PB (S100).

<S102>
Next, the control unit 14 irradiates the laser light source LA with the laser light LA during the period PA, and outputs the ON information SA to the image analysis unit 13 (S102).

<S104>
Next, upon receiving the ON information SA from the control unit 14, the image analysis unit 13 performs a coordinate calculation process of the image ISA (S104). The details of the image ISA coordinate calculation process will be described later.

<S106>
Next, the control unit 14 causes the laser light source 11A to stop emitting the laser beam LA at the end timing of the period PA (S106).

<S108>
Next, the control unit 14 irradiates the laser light source 11B with the laser light LB during the period PB, and outputs the ON information SB to the image analysis unit 13 (S108).

<S110>
Next, upon receiving the ON information SB from the control unit 14, the image analysis unit 13 performs a coordinate calculation process of the image ISB (S110). Details of the coordinate calculation processing of the image ISB will be described later.

<S112>
Next, the control unit 14 causes the laser light source 11B to stop emitting the laser light LB at the end timing of the period PB (S112).

<S114>
Next, the image analysis unit 13 calculates the distance IDh from the entire image coordinates CA of the image ISA and the entire image coordinates CB of the image ISB (S114).

<S116>
Next, the image analysis unit 13 calculates the distance Dv based on the distance IDh using an approximate expression indicating the relationship between the distance IDh and the distance Dv (S116).

<S118>
Next, the image analysis unit 13 determines whether the image ISA is located on the left side of the image ISB based on the entire image coordinates CA and the image ISB (S118).

<S120>
Next, when the image ISA is located on the left side of the image ISB (YES in S118), the image analysis unit 13 determines that the measurement target surface 33A is located on the light source side with respect to the regular reflection surface MRS (S120). .

<S122>
On the other hand, when the image ISA is located on the right side of the image ISB (NO in S118), the image analysis unit 13 determines that the measurement target surface 33A is located on the non-light source side with respect to the regular reflection surface MRS (S122). .

<S124>
Next, the image analysis unit 13 calculates the position of the measurement target surface 33A based on the calculated distance Dv and the determination result, and outputs position information including the calculation result to the marking unit 32 (S124).

<S126>
Next, when receiving the position information from the image analysis unit 13, the marking unit 32 adjusts the focusing position of the marking laser based on the received position information, oscillates the marking laser, and changes the target dot MD. Marking is performed (S126).

<S128>
Next, when the marking of the target dot MD is completed by the marking unit 32, the marking process in the laser marking device 31 ends (S128).

  In addition, each process in the above-described flowchart may be replaced within a range that does not affect the operation. For example, the order of the processes of S102 to S106 and S108 to S112 in the above flowchart may be interchanged. Further, the order of the processes of S114 to S116 and S118 to S122 in the above flowchart may be interchanged.

<Image ISA coordinate calculation process>
Next, a coordinate calculation process of the image ISA in the laser marking device of the present embodiment will be described with reference to FIG. FIG. 13 is a flowchart illustrating a coordinate calculation process of the image ISA in the laser marking device of the present embodiment. FIG. 13 shows details of the operation in step S104 in FIG.

<S200 to S202>
Upon receiving the ON information SA from the control unit 14 (S200), the overall image adjustment unit 21 in the image analysis unit 13 outputs an imaging command including the entire range and the initial value ETA as the imaging area and the exposure time to the camera 12 ( S202).

<S204>
Next, when the camera 12 receives the imaging command from the entire image adjustment unit 21, the camera 12 captures an image of the bright spot SA on the measurement target surface 33A with the imaging area and the exposure time included in the imaging command, and based on the imaging result, the bright spot SA Generate an image IA that includes the image ISA of the image. The camera 12 outputs image information including the generated image IA to the whole image adjustment unit 21 (S204).

<S206>
Next, when receiving the image information from the camera 12, the overall image adjustment unit 21 specifies the maximum pixel PEA based on the image information and determines whether or not the pixel value of the maximum pixel PEA is included in the range MaxA (S206). ). When the pixel value of the maximum pixel PEA is not included in the range MaxA (NO in S206), the entire image adjustment unit 21 changes the exposure time of the camera 12 so that the pixel value of the maximum pixel PEA is included in the range MaxA ( S202).

<S208>
On the other hand, when the pixel value of the maximum pixel PEA is included in the range MaxA (YES in S206), the entire image adjustment unit 21 outputs image information including the first setting image to the region setting unit 22. Upon receiving the image information from the entire image adjustment unit 21, the area setting unit 22 acquires the entire image coordinates of the maximum pixel PEA based on the image information (S208).

<S210>
Next, the area setting unit 22 sets a rectangular area RA having a predetermined size around the maximum pixel PEA based on the entire image coordinates of the maximum pixel PEA, and includes a fourth area including the entire image coordinates of the four corners of the area RA. 1 is output to the partial image adjustment unit 23 (S210).

<S212>
Next, when receiving the first region information from the region setting unit 22, the partial image adjustment unit 23 outputs an imaging command including the first region information and the initial value ETRA as the imaging region and the exposure time to the camera 12, respectively. (S212).

<S214>
Next, when the camera 12 receives the imaging command from the partial image adjustment unit 23, the camera 12 captures an image of the bright spot SA on the measurement target surface 33A using the imaging region and the exposure time included in the imaging command, and converts the partial image PIA based on the imaging result. Generate. The camera 12 outputs image information including the generated partial image PIA to the partial image adjustment unit 23 (S214).

<S216>
Next, when receiving the image information from the camera 12, the partial image adjustment unit 23 calculates the average value of the pixel values of the pixels included in the partial image PIA based on the image information (S216).

<S218>
Next, the partial image adjustment unit 23 determines whether or not the average value is included in the range AveA (S218). When the average value is not included in the range AveA (NO in S218), the partial image adjustment unit 23 changes the exposure time of the camera 12 so that the average value is included in the range AveA (S212).

<S220>
On the other hand, when the average value is included in the range AveA (YES in S218), the partial image adjustment unit 23 outputs the first partial image information including the partial image PIA to the processing unit 24 and measures the first area information. Output to the unit 25. When the processing unit 24 receives the first partial image information from the partial image adjustment unit 23, the processing unit 24 performs a binarization process, a contraction process, and an expansion process on the partial image PIA included in the first partial image information. The first processed image information including the subsequent partial image PIA is output to the measurement unit 25 (S220).

<S222>
Next, when receiving the first processed image information from the processing unit 24, the measuring unit 25 calculates the partial image coordinates PCA of the center of gravity of the pixels included in the partial image PIA based on the received first processed image information. calculate. Then, the measuring unit 25 converts the partial image coordinates PCA into the whole image coordinates CA based on the first area information received from the partial image adjusting unit 23 (S222).

<S224>
The overall image coordinates CA calculated in this way are determined as the coordinates of the image ISA (S224).

<Image ISB coordinate calculation process>
Next, a coordinate calculation process of the image ISB in the laser marking device of the present embodiment will be described with reference to FIG. FIG. 14 is a flowchart illustrating a coordinate calculation process of the image ISB in the laser marking device of the present embodiment. FIG. 14 shows details of the operation in step S110 in FIG.

<S300 to S302>
Upon receiving the ON information SB from the control unit 14 (S300), the overall image adjustment unit 21 in the image analysis unit 13 outputs to the camera 12 an imaging command including the entire range and the initial value ETB as the imaging region and the exposure time, respectively ( S302).

<S304>
Next, when the camera 12 receives the imaging command from the entire image adjustment unit 21, the camera 12 captures an image of the bright spot SB on the measurement target surface 33A using the imaging area and the exposure time included in the imaging command, and based on the imaging result, the bright spot SB An image IB including the image ISB is generated. The camera 12 outputs the image information including the generated image IB to the whole image adjustment unit 21 (S304).

<S306>
Next, when receiving the image information from the camera 12, the overall image adjustment unit 21 specifies the maximum pixel PEB based on the image information, and determines whether or not the pixel value of the maximum pixel PEB is included in the range MaxB (S306). ). If the pixel value of the maximum pixel PEB is not included in the range MaxB (NO in S306), the entire image adjustment unit 21 changes the exposure time of the camera 12 so that the pixel value of the maximum pixel PEB is included in the range MaxB ( S302).

<S308>
On the other hand, when the pixel value of the maximum pixel PEB is included in the range MaxB (YES in S306), the entire image adjustment unit 21 outputs image information including the second setting image to the region setting unit 22. Upon receiving the image information from the entire image adjustment unit 21, the area setting unit 22 acquires the entire image coordinates of the maximum pixel PEB based on the image information (S308).

<S310>
Next, the region setting unit 22 sets a rectangular region RB having a predetermined size centered on the maximum pixel PEB based on the entire image coordinates of the maximum pixel PEB, and includes a fourth region including the entire image coordinates of the four corners of the region RB. The second area information is output to the partial image adjustment unit 23 (S310).

<S312>
Next, when receiving the second region information from the region setting unit 22, the partial image adjustment unit 23 outputs an imaging command including the second region information and the initial value ETRB as the imaging region and the exposure time to the camera 12, respectively. (S312).

<S314>
Next, when the camera 12 receives the imaging command from the partial image adjustment unit 23, the camera 12 captures an image of the bright spot SB on the measurement target surface 33A using the imaging region and the exposure time included in the imaging command, and generates a partial image PIB based on the imaging result. Generate. The camera 12 outputs image information including the generated partial image PIB to the partial image adjustment unit 23 (S314).

<S316>
Next, when receiving the image information from the camera 12, the partial image adjustment unit 23 calculates the average value of the pixel values of the pixels included in the partial image PIB based on the image information (S316).

<S318>
Next, the partial image adjustment unit 23 determines whether or not the average value is included in the range AveB (S318). When the average value is not included in the range AveB (NO in S318), the partial image adjustment unit 23 changes the exposure time of the camera 12 so that the average value is included in the range AveB (S312).

<S320>
On the other hand, when the average value is included in the range AveB (YES in S318), the partial image adjustment unit 23 outputs the second partial image information including the partial image PIB to the processing unit 24 and measures the second area information. Output to the unit 25. When receiving the second partial image information from the partial image adjustment unit 23, the processing unit 24 performs a binarization process, a contraction process, and an expansion process on the partial image PIB included in the second partial image information, and The second processed image information including the subsequent partial image PIB is output to the measuring unit 25 (S320).

<S322>
Next, when receiving the second processed image information from the processing unit 24, the measuring unit 25 calculates the partial image coordinates PCB of the center of gravity of the pixels included in the partial image PIB based on the received second processed image information. calculate. Then, the measuring unit 25 converts the partial image coordinates PCB into the whole image coordinates CB based on the second area information received from the partial image adjusting unit 23 (S322).

<S324>
The overall image coordinates CB calculated in this way are determined as the coordinates of the image ISB (S324).

<2. Features of the present invention>
According to the measuring device having the above configuration, the first imaging setting is performed so that the pixel value of the maximum pixel PEA is included in the range MaxA, and thus the pixels of the plurality of pixels forming the image of the bright spot SA in the image IA The value can be within a certain range. Thereby, even when the material of the target 33 changes and the brightness of the bright spot SA changes, the image of the bright spot SA can be drawn well in the image IA, so that the area RA is appropriately set. be able to. Then, since the partial image PIA included in the area RA is processed by the processing unit 24, the data amount of the image processing can be reduced, so that the processing load can be reduced and the processing time can be shortened. Also, for example, by performing image processing for accurately measuring the position of the image of the bright spot in the image, such as binarization processing, contraction processing, and expansion processing, on the partial image PIA, the bright spot SA in the image IA is obtained. Can be accurately measured. Thereby, the measurement accuracy of the position of the target 33 can be improved.

  In the measuring device having the above configuration, the camera 12 captures the bright spot SA to generate the partial image PIA, and the partial image adjustment unit 23 determines that the statistical value of the pixel value of the pixel included in the partial image PIA, for example, the average value is within the range. The second imaging setting is performed so as to be included in AveA, and the processing unit 24 processes the partial image PIA for which the second imaging setting has been performed. Thereby, for example, since the imaging range of the camera 12 can be reduced to a range corresponding to the area RA, the time required for the camera 12 to generate the partial image PIA can be reduced. In addition, since the outline of the image of the bright spot SA in the partial image PIA can be drawn well, for example, even when the material of the object 33 changes and the brightness of the bright spot SA changes, the partial image Variations in the shape of the image of the bright spot SA in the PIA can be suppressed.

  In the measuring device having the above configuration, the measuring unit 25 configures the image of the bright spot SA to measure the position of the target 33 based on the entire image coordinates CA of the center of gravity of the pixels included in the processed partial image PIA. The whole image coordinates CA of the center of gravity can be determined based on the distribution of the pixel values of the plurality of pixels. Thereby, for example, even when the image of the bright spot SA is shifted from the center of the partial image PIA, the entire image coordinates CA of the bright spot SA can be correctly calculated, so that the measurement accuracy of the position of the target 33 is improved. Can be done.

  In the measuring device having the above configuration, since the predetermined condition CMA is to have the maximum pixel value in the detection range, the maximum value of the pixel values of a plurality of pixels constituting the bright spot SA in the image IA is set in the range MaxA. Since it can be accommodated, it is possible to suppress the occurrence of pixels that have reached the upper limit of the pixel value, for example, 255.

  In the measuring device having the above configuration, the first imaging setting is to set the exposure time in the camera 12, so that, for example, compared with adjusting the intensity of the laser light LA or inserting a filter into the laser light LA, The first imaging setting in which the pixel value of the maximum pixel PEA is included in the range MaxA can be easily realized.

  In the measuring device having the above configuration, since the second imaging setting is to set the exposure time in the camera 12, for example, compared with adjusting the intensity of the laser light LA or inserting a filter into the laser light LA, The second imaging setting in which the average value of the pixel values of the pixels included in the partial image PIA is included in the range AveA can be easily realized.

  In the measuring device having the above configuration, the laser light source 11B irradiates the target 33 with the laser light LB, the camera 12 captures an image of the bright spot SB of the laser light LB on the target 33, and generates an image IB including the bright spot SB. Generate. Then, the whole image adjustment unit 21 performs the third imaging setting so that the pixel value of the maximum pixel PEB, which is the pixel satisfying the condition CMB, is included in the range MaxB among the plurality of pixels forming the image of the bright spot SB. . Then, the region setting unit 22 sets a region RB including a part of the image IB and including the bright spot SB based on the maximum pixel PEB included in the image IB on which the third imaging setting has been performed, The processing unit 24 processes the partial image PIB which is an image included in the region RB. Then, the measuring unit 25 measures the position of the target 33 based on the processed partial image PIA and the processed partial image PIB. Thus, for example, even when the reflectance of the laser beam LA near the bright point SA and the reflectance of the laser beam LB near the bright point SB are different, the position of the bright point SA in the image IA and the bright point in the image IB Both of the SB positions can be measured with high accuracy. Thus, for example, in a configuration in which the laser beams LA and LB are applied to the target 33 and the position of the target 33 is measured based on the distance IDh between the bright points SA and SB in the image, Position measurement accuracy can be improved.

<3. Supplementary items>
The specific description of the embodiment of the present invention has been given above. The above description is merely an example of the embodiment, and the scope of the present invention is not limited to this embodiment, but is widely interpreted to a range that can be understood by those skilled in the art.

  In the measuring device of the present embodiment, the configuration in which the laser light sources 11A and 11B are provided has been described, but the measuring device 1 may have a configuration in which one laser light source is provided. Even with such a configuration, for example, as in a laser marker described in Patent Literature 1, an approximate expression indicating the relationship between the entire image coordinates of a bright spot image in an image and the distance Dv, or a plurality of bright spot images It is possible to measure the position of the target 33 by using a table indicating the correspondence between the entire image coordinates of the above and the plurality of distances Dv.

  Further, in the measuring apparatus of the present embodiment, the laser light sources 11A and 11B have been described as a specific example of the irradiating unit. However, the irradiating unit may be configured to irradiate the target object 33 with laser light. A mirror that reflects the laser light from the mirror and irradiates the object 33 with the laser beam, an optical fiber exit port, or the like may be used.

  Further, in the measurement apparatus of the present embodiment, the configuration has been described in which the laser beams LA and LB are irradiated on the target 33 one by one at a shifted timing, but the laser beams LA and LB are emitted at the same timing. May be applied. In this case, for example, the size, brightness or color of the bright spots SA and SB are made different from each other, or the range where the bright spot SA can be located without crossing the laser beams LA and LB and the bright spot SB are located. And the range to be obtained is different from each other. This makes it possible to determine whether the measurement target surface 33A is located on the light source side or the non-light source side with respect to the regular reflection surface MRS.

  Further, in the measurement apparatus of the present embodiment, the configuration has been described in which the camera 12 captures an image using the light receiving element portion corresponding to the region RA or RB and generates a partial image. A configuration for generating an image may be used. Specifically, for example, the camera 12 captures an image using the entire surface of the light receiving element to generate an image IA, and outputs image information including the image IA to the partial image adjustment unit 23. When receiving the image information from the camera 12, the partial image adjustment unit 23 generates a partial image by cutting out the partial image PIA included in the area RA from the image IA included in the image information. However, in the configuration in which the camera 12 generates the image IA or IB, the imaging time becomes long. Therefore, the configuration in which the camera 12 generates the partial image PIA or PIB is preferable.

  Further, in the measuring device of the present embodiment, the camera 12 is described as being provided so that the optical axis is along a bisector Bis bisecting the intersection angle of the laser beams LA and LB. The optical axis may be provided at a position deviating from the bisector Bis.

  Further, in the measurement apparatus according to the present embodiment, the configuration has been described in which the processing unit 24 performs the binarization processing, the contraction processing, and the expansion processing on the partial image, but the processing unit 24 performs the binarization processing, the contraction processing And any one or two of the expansion processing may be performed. As described above, by performing the image processing for accurately measuring the position of the bright spot in the partial image, the center of gravity based on the noise of the laser beam, the shape of the bright spot that changes depending on the material of the object 33, and the like can be obtained. The calculation error of the whole image coordinates can be suppressed.

  Further, in the measurement apparatus of the present embodiment, the configuration in which the processing unit 24 processes the partial image on which the second imaging setting has been performed has been described, but the processing unit 24 has a configuration in which the second imaging setting is not performed. A configuration for processing an image may be used. However, when the second imaging setting is not performed, the outline of the luminescent spot in the partial image is roughly drawn. Therefore, the processing unit 24 is configured to process the partial image PIA on which the second imaging setting is performed. preferable.

  INDUSTRIAL APPLICABILITY The measuring device and the laser marking device of the present invention are suitably applied to, for example, marking of an object having an uneven surface.

DESCRIPTION OF SYMBOLS 1 ... Measurement apparatus 11A, 11B ... Laser light source 12 ... Camera 13 ... Image analysis part 14 ... Control part 21 ... Whole image adjustment part 22 ... Area setting part 23 ... Partial image adjustment part 24 ... Processing part 25 ... Measurement part 31 ... Laser Marking device 32 ... Marking part 33 ... Target object 33A ... Measurement target surface Bi ... Bissant line CS ... Intersection FR ... Photographable range ISA, ISB ... Image LA, LB ... Laser beam MR ... Measureable range MRS ... Specular reflection surface MD: dots SA, SB: bright spots RA, RB: areas IA, IB: images PIA, PIB: partial images PEA, PEB: maximum pixels

Claims (10)

A first irradiating unit that irradiates the first laser light to the object,
An imaging unit that captures an image of a first luminescent spot that is a luminescent spot of the first laser light on the object, and generates a first image including the first luminescent spot;
First imaging for performing first imaging setting so that a pixel value of a first target pixel which is a pixel satisfying a predetermined condition among a plurality of pixels constituting the first bright spot is included in a predetermined range. A setting section,
A region including a part of the first image and including the first luminescent spot, based on the first target pixel included in the first image on which the first imaging setting is performed; An area setting unit for setting an area 1;
A processing unit that processes a first partial image that is an image included in the first region;
A measurement unit that measures the position of the object based on the processed first partial image,
measuring device. The imaging unit captures the first luminescent spot to generate the first partial image,
A second imaging setting unit configured to perform a second imaging setting so that a statistical value of a pixel value of a pixel included in the first partial image is included in a predetermined range;
The processing unit processes the first partial image on which the second imaging setting is performed;
The measuring device according to claim 1. The measurement unit measures a position of the target object based on a position of a center of gravity of a pixel included in the processed first partial image.
The measuring device according to claim 1. The predetermined condition is to have a maximum pixel value in a detection range,
The measuring device according to claim 1. The processing unit performs at least one of a binarization process, a contraction process, and an expansion process on the first partial image;
The measuring device according to claim 1. The first imaging setting is to set an exposure time in the imaging unit.
The measuring device according to claim 1. The second imaging setting is to set an exposure time in the imaging unit.
The measurement device according to claim 2. A second irradiation unit that irradiates the object with a second laser beam,
The imaging unit captures a second luminescent spot that is a luminescent spot of the second laser light on the object, and further generates a second image including the second luminescent spot,
The first imaging setting unit performs the third imaging so that a pixel value of a second target pixel that is a pixel satisfying a predetermined condition among a plurality of pixels forming the second bright spot is included in a predetermined range. Perform further imaging settings for
The area setting unit is an area including a part of the second image based on the second target pixel included in the second image on which the third imaging setting is performed, and And further setting a second area including a bright spot of
The processing unit further processes a second partial image that is an image included in the second area,
The measuring unit measures the position of the object based on the first partial image after the processing and the second partial image after the processing,
The measuring device according to any one of claims 1 to 7. A measuring device according to any one of claims 1 to 8,
Based on the result measured by the measuring device, and a marking unit that performs laser marking on the object,
Laser marking device. A measurement method in a measurement device including a first irradiation unit that irradiates a first laser beam to an object,
Imaging a first luminescent spot, which is a luminescent spot of the first laser light, on the object, and generating a first image including the first luminescent spot;
Performing a first imaging setting so that a pixel value of a first target pixel that is a pixel satisfying a predetermined condition among a plurality of pixels forming the first bright spot is included in a predetermined range;
A region including a part of the first image and including the first luminescent spot, based on the first target pixel included in the first image on which the first imaging setting is performed; Setting an area 1;
Processing a first partial image that is an image included in the first area;
Measuring the position of the object based on the processed first partial image,
Measuring method.

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