Hole presence / absence detection system and hole presence / absence detection method

Abstract

It detects with high precision whether or not there are through holes in manufactured parts. [Solution] A hole presence / absence detection system for detecting the presence or absence of through holes in a component is configured with a light source that irradiates light of a predetermined wavelength or wavelength range set based on the light components contained in ambient light, a camera that images the component through a filter that blocks light other than the predetermined wavelength range including the wavelength of light irradiated by the light source, and a determination device that determines the presence or absence of through holes based on a difference image between a first image taken by the camera with the light source off and a second image taken by the camera with the light source on, and the component is arranged such that the brightness value of the through hole portion included in the first image is approximately the same as the brightness value of the through hole portion included in the second image.

Description

Technical Field

[0004] , ,

[0005] , ,

[0001] The present disclosure relates to a through-hole presence / absence detection system and a through-hole presence / absence detection method for detecting the presence or absence of through-holes in manufactured parts.

Background Art

[0002] Conventionally, at the site of product manufacturing, devices for detecting the presence or absence of holes in manufactured parts have been used. For example, Patent Document 1 discloses an inspection device for detecting hole defects at welding locations. This device utilizes the fact that infrared light irradiated on a welding location is diffusely reflected by hole defects, and compares an image obtained by irradiating infrared light and imaging a part to be inspected with an image obtained by imaging a part without hole defects under the same conditions to detect the presence or absence of hole defects.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] During product manufacturing, depending on the product specifications, there may be cases where two types of parts are used: parts with through-holes and parts without through-holes. For example, in products with specifications that include a sensor and those that do not, for the specification that includes a sensor, a part with a through-hole formed for sensor mounting is used, while for the specification that does not include a sensor, a part without a through-hole may be used. If it is detected on the manufacturing line whether a part has a through-hole or not, it is possible to determine the necessity of sensor mounting in subsequent processes. [[ID=​The conventional technology described above is a technique for detecting surface roughness defects, and therefore may not be suitable for detecting the presence or absence of machined holes without roughness around through-holes. For example, even if infrared light is shone on a part with a through-hole and image is taken, the infrared light may not be scattered as much as it would be for a hole defect, and an image clearly showing the through-hole may not be captured. Specifically, when infrared light is shone from the surface side of a part, the infrared light that passes through the through-hole may be reflected by the wall, floor, support stand, etc. on the back side of the part, and may appear in the captured image just like the infrared light reflected from the surface of the part. In this case, the difference in brightness between the infrared light reflected from the surface of the part around the through-hole and the infrared light that has passed through the through-hole, been reflected by the support stand etc. on the back side, and passed through the through-hole again will be small, and it may not be possible to accurately detect the presence or absence of a through-hole from the captured image.

[0006] This disclosure has been made in view of the problems of the prior art described above, and one of its purposes is to provide a hole presence / absence detection system and a hole presence / absence detection method that can detect the presence or absence of through holes in manufactured parts with high accuracy. [Means for solving the problem]

[0007] The hole position detection system according to this disclosure is a hole presence / absence detection system for detecting the presence or absence of through holes in a component, comprising: a light source that irradiates light of a predetermined wavelength or wavelength range set based on the light components contained in ambient light; a camera that images the component through a filter that blocks light other than the predetermined wavelength range including the wavelength of light irradiated by the light source; and a determination device that determines the presence or absence of through holes based on a difference image between a first image taken by the camera with the light source turned off and a second image taken by the camera with the light source turned on, wherein the component is arranged such that the brightness value of the through hole portion included in the first image is approximately the same as the brightness value of the through hole portion included in the second image. That is, the placement position of the component in the hole position detection system is set to a position where the brightness value of the through hole portion is approximately the same in the first image and the second image. For example, if simply placing the component on the floor results in the brightness value of the through hole portion being approximately the same in the first image and the second image, then the component should be imaged at the placement position set on the floor. If support for the component is necessary, the placement position of the component may be set using a support member.

[0008] In the above configuration, the component may be positioned so that indirect light irradiated from the light source and bends around the component from the outside to the back side does not pass through the through-hole of the component from the back side.

[0009] In the above configuration, a shielding plate may be further provided to block indirect light that is irradiated from the light source and wraps around from the outside to the back side of the component.

[0010] In the above configuration, the support base may be further provided, which positions and supports the component and has a shape near the back surface of the component that does not block the optical path of the light irradiated from the light source and passing through the through hole of the component.

[0011] In the above configuration, the support base includes a support member that supports the component from the back side, and the support member may be positioned so that the light irradiated from the light source, passing through the through hole from the front side of the component and reflected by the support member on the back side is not captured by the camera through the through hole.

[0012] In the above configuration, the wavelength or wavelength range of the light emitted from the light source may be a wavelength or wavelength range in which the amount of light contained in the ambient light is small.

[0013] In the above configuration, the light emitted from the light source may be infrared light of a predetermined wavelength or wavelength range.

[0014] The hole presence / absence detection method according to this disclosure is a hole presence / absence detection method for detecting the presence or absence of through holes in a component, and includes the steps of: turning off a light source that emits light of a predetermined wavelength or wavelength range set based on the light components contained in ambient light, and acquiring a first image of the component by a camera equipped with a filter that blocks light other than the predetermined wavelength range including the wavelength of light emitted by the light source; turning on the light source and irradiating the component with light, and acquiring a second image of the component by the camera; and determining the presence or absence of through holes based on a difference image between the first image and the second image, wherein the component is arranged such that the brightness value of the through hole portion included in the first image is approximately the same as the brightness value of the through hole portion included in the second image. [Effects of the Invention]

[0015] According to the hole presence / absence detection system and hole presence / absence detection method described herein, the brightness value of the through-hole portion is approximately the same in the captured image with the light source on and the captured image with the light source off, while the brightness value of the component surface around the through-hole changes. As a result, the difference image of the two captured images becomes an image in which the through-hole portion is clearly visible, making it possible to detect the presence or absence of a through-hole with high accuracy. [Brief explanation of the drawing]

[0016] [Figure 1]FIG. 1 is a schematic diagram for explaining the outline of the hole presence / absence detection system according to the present embodiment. [Figure 2] FIG. 2 is a block diagram showing a configuration example of the hole presence / absence detection system. [Figure 3] FIG. 3 is a flowchart showing an example of the processing flow performed in the hole presence / absence detection system. [Figure 4] FIG. 4 is a schematic diagram for explaining a specific arrangement example of the camera, light source, and components. [Figure 5] FIG. 5 is a diagram showing an example of a specific component that is the target of hole presence / absence detection. [Figure 6] FIG. 6 is a diagram showing an example of a specific image obtained by the hole presence / absence detection system. [Figure 7] FIG. 7 is a diagram for explaining another example of the support base of the component and an example of using the shielding plate.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the hole presence / absence detection system and the hole presence / absence detection method according to the present disclosure will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram for explaining the outline of the hole presence / absence detection system 1 according to the present embodiment. The hole presence / absence detection system 1 includes a determination device 10, a camera 100, and a light source 200.

[0018] The light source 200 irradiates the component 300 to be imaged with light of a predetermined wavelength or wavelength range. The light source 200 irradiates light of a wavelength or wavelength range that is not included in the ambient light or has a small amount of light included in the ambient light. For example, the hole presence / absence detection system 1 is installed indoors using white LED lighting, and a predetermined wavelength or wavelength range of infrared light in the infrared light region that is hardly included in the ambient light by the white LED is irradiated from the light source 200. In an indoor environment using white LEDs, ultraviolet light of a predetermined wavelength or wavelength range in the ultraviolet light region may be irradiated from the light source 200.

[0019] The camera 100 images the component 300 to be imaged. A through-hole 300a, which is a detection target by the hole presence / absence detection system 1, is formed in the component 300. The camera 100 images at least a partial area including the through-hole 300a and outputs a monochrome image. The camera 100 includes a filter 101 that transmits the light irradiated by the light source 200 while blocking light in other wavelength ranges. Due to the function of the filter 101, the camera 100 receives light in a predetermined wavelength range including the light irradiated from the light source 200 by the imaging element to image an image.

[0020] As shown by the dashed arrow in Fig. 1(a), the light source 200 is arranged such that part of the irradiated light is reflected by the surface of the component 300 and part of it passes through the through-hole 300a and reaches the back side of the component 300. The light that has passed through the through-hole 300a is reflected by, for example, the floor surface 20.

[0021] The component 300 is fixed at a position separated from the floor surface 20 by a distance d. The component 300 may be supported, for example, using a jig or a support base that protrudes from the wall surface. Although not shown in Fig. 1, examples of the support base will be described later.

[0022] For example, the distance d is set such that the luminance value of the area corresponding to the through-hole 300a, that is, the pixel value of the pixel corresponding to the through-hole 300a, is substantially the same between the image obtained by irradiating light from the light source 200 and imaging with the camera 100 and the image obtained by imaging with the camera 100 under ambient light without irradiating light from the light source 200.

[0023] As shown in Fig. 1(a), the light source 200 is arranged such that even if the indirect light that irradiates from the light source 200 and wraps around from the outside to the back side of the component 300 is reflected by the floor surface 20, it does not pass through the through-hole 300a from the back side and is not reflected in the captured image.

[0024] As shown by the dashed arrow in Figure 1(a), of the light emitted from the light source 200, the reflected light reflected from the surface of the component 300 reaches the camera 100, while the transmitted light that passes through the through-hole 300a and reaches the back side of the component 300 is set at a distance d such that even if it is reflected by the floor surface 20, it passes through the through-hole 300a again and reaches the camera 100. In other words, the component 300 is positioned such that almost all of the light emitted from the light source 200 and passing through the through-hole 300a is not reflected from the back side of the component 300 and captured in the image taken by the camera 100.

[0025] The positional relationship between the camera 100, the light source 200, the component 300 having the through-hole 300a, and the surrounding walls and floor is set such that, in the image captured by the camera 100, the brightness value (pixel value) of the surface of the component 300 around the through-hole 300a changes depending on whether or not there is illumination from the light source 200, while the brightness value of the through-hole 300 portion remains approximately the same regardless of the presence or absence of illumination from the light source 200. The through-hole 300a portion that appears in the captured image is an image of the ambient light on the back side of the component 300.

[0026] The determination device 10 controls the camera 100 and the light source 200 to acquire an image of the part 300 captured by the camera 100 with the light source 200 off, and an image of the part 300 captured by the camera 100 with the light source 200 on.

[0027] Figure 1(b) shows a partial image extracted from the captured image, including a portion of the area containing the through-hole 300a. The actual image is a monochrome image with different brightness values ​​(pixel values) for the through-hole 300a and the surrounding surface of component 300 (see Figure 6), but in Figure 1(b), the difference in brightness values ​​is shown by a pattern.

[0028] Image 401 on the left was taken under ambient light with the light source 200 turned off. Image 402 on the right was taken with the light source 200 turned on, illuminating the surface of component 300 with light from the light source 200. Hereafter, images taken under ambient light with the light source 200 turned off will be referred to as "light source off images," and images taken with the light source 200 turned on will be referred to as "light source on images" to distinguish them.

[0029] Camera 100 outputs a monochrome image of component 300 via a filter 101 that transmits only light in a predetermined wavelength range corresponding to the light emitted from light source 200. The ambient light contains almost no light in the wavelength range corresponding to the light emitted from light source 200. Therefore, the light source off image 401 obtained under ambient light with light source 200 turned off is a dark image in both the region 401a corresponding to the through hole 300a and the region 401b corresponding to the surface of component 300. In other words, the brightness value of region 401b is small in the light source off image 401.

[0030] In the light source-on image 402, the surface of component 300 that reflects the light emitted from the light source 200 becomes brighter. That is, in the light source-on image 402, the brightness value of region 402b increases. Component 300 is arranged such that the brightness value of the through-hole 300a portion is approximately the same regardless of whether or not light is emitted from the light source 200. Therefore, even in the light source-on image 402, the brightness value of region 402a corresponding to the through-hole 300a is approximately the same as the brightness value of region 401a in the light source-off image 401.

[0031] Depending on the type of light emitted from the light source 200 and the material and shape of the surface of the component 300, the off-light image 401 tends to have low brightness in both regions 401a and 401b, and even if there is a difference in brightness between the regions, it tends to be an image with ambiguous boundaries and low contrast. Similarly, the on-light image 402 may also have little difference in brightness between the two regions 402a and 402b, resulting in an image with ambiguous boundaries and low contrast.

[0032] The determination device 10 generates a difference image 403 between the light source off image 401 and the light source on image 402. For example, the difference image 403 is generated by subtracting the brightness value of each corresponding pixel in the light source off image 401 from the brightness value of each pixel in the light source on image 402, in which the surface of the part 300 is brightly depicted. In this case, the region 403b corresponding to the surface of the part 300 will be an image with a brightness value smaller than region 402b, obtained by subtracting the brightness value of region 401b in the light source off image 401 from the brightness value of region 402b in the light source on image 402. On the other hand, for the region corresponding to the through hole 300a, since region 402a in the light source on image 402 and region 401a in the light source off image 401 have approximately the same brightness value, region 403a in the difference image 403 will be an image with a brightness value of approximately 0 (zero).

[0033] As a result, as shown in Figure 1(b), the difference image 403 is a high-contrast image in which the boundary between the surface of the part 300 and the through hole 300a is clearly defined. The determination device 10 uses the difference image 403 to detect the presence or absence of the through hole 300a. This allows the determination device 10 to detect the presence or absence of the through hole 300a with higher accuracy compared to when using the light source off image 401 or the light source on image 402.

[0034] Figure 2 is a block diagram showing an example configuration of the pore detection system 1. The type of light emitted by the light source 200 is not particularly limited and is set appropriately according to the wavelength components of the ambient light at the installation location of the pore detection system 1. However, the following explanation will continue assuming that the light source 200 emits infrared light in a predetermined wavelength range.

[0035] Figure 1 shows an example with one camera 100 and one light source 200, but the number of cameras 100 and light sources 200 is not particularly limited. For example, if a component 300 has multiple through holes 300a and one light source 200 cannot illuminate the area around all the through holes 300a with infrared light, then multiple light sources 200 can be used. Similarly, if one camera 100 cannot image all the through holes 300a, then multiple cameras 100 can be used. Each camera 100 should be positioned so that each through hole 300a is imaged by at least one camera 100 in a way that allows the back side of the component 300 to be seen from the through hole 300a.

[0036] The determination device 10 includes a control unit 11, a storage unit 12, an operation unit 13, and a display unit 14. The control unit 11 includes a camera control unit 11a, a light source control unit 11b, an image processing unit 11c, and a determination processing unit 11d.

[0037] The memory unit 12 is a non-volatile memory device that stores information related to the control of the camera 100 and the light source 200, images captured by the camera 100 and difference images generated from said captured images, and information related to the process of determining whether or not there are holes.

[0038] The operation unit 13 can accept input of various information related to the hole presence / absence determination process. The display unit 14 can display various information such as the image captured by the camera 100 and the hole presence / absence determination result.

[0039] The control unit 11 controls each part of the determination device 10. For example, a program corresponding to the control unit 11 is pre-stored in the storage unit 12 or a dedicated storage device, and the functions and operation of the control unit 11 are realized when this program is executed by hardware such as a CPU. The control unit 11 can control each part based on information input via the operation unit 13 and information stored in the storage unit 12. The functions and operation of the hole presence / absence detection system 1 described in this embodiment are realized by the control unit 11.

[0040] This will be explained in detail using the flowchart shown in Figure 3. Figure 3 shows an example of the processing flow performed by the hole presence / absence detection system 1. The determination device 10 images the part 300 with the light source 200 turned off (step S1). The determination device 10 also images the part 300 with the light source 200 turned on (step S2). Steps S1 and S2 may also be executed in the reverse order.

[0041] The light source control unit 11b controls the on / off switching of the light source 200. The camera control unit 11a controls the camera 100 to image the component 300 and stores the obtained image in the storage unit 12. The storage unit 12 stores both an off-light source image, which is taken when the light source 200 is turned off and the component 300 is imaged under ambient light that contains almost no infrared light, and an on-light source image, which is taken when the light source 200 is turned on and infrared light is shone on the component 300.

[0042] The determination device 10 generates a difference image between the light source on image and the light source off image (step S3). The image processing unit 11c generates a difference image from the light source on image and light source off image stored in the storage unit 12. If the image captured by the camera 100 is an image of the part 300 over a wide area, the image processing unit 11c may cut out a predetermined partial region including the through hole 300a from the captured image and generate a difference image from the obtained partial image.

[0043] The determination device 10 uses the difference image to perform a determination process to determine whether or not the part 300 has a through hole 300a (step S4). The storage unit 12 has information necessary for the determination process prepared in advance. For example, a template image generated by cutting out the part with the through hole 300a from the difference image of the part 300 that has the through hole 300a, and a threshold value for determining the presence or absence of the through hole using this template image are stored in the storage unit 12.

[0044] The determination processing unit 11d scans the difference image generated by the image processing unit 11c with the template image read from the storage unit 12, and calculates the correlation coefficient between the difference image and the template image at each position. If the determination processing unit 11d obtains a correlation coefficient that exceeds a threshold read from the storage unit 12, it determines that the part 300 has a through hole 300a. In other words, if the determination processing unit 11d does not obtain a correlation coefficient that exceeds a threshold, it determines that the part 300 does not have a through hole 300a.

[0045] The determination device 10 notifies the result of the determination process (step S5). For example, the determination processing unit 11d displays information indicating the determination result on the display unit 14. The notification method is not particularly limited, and the display unit 14 may display, in addition to the determination result, an image captured by the camera 100, a difference image, a template image, etc. The determination result may be notified using sound or light. The information indicating the determination result may be notified to other processing units included in the control unit 11, and another process may be executed using the determination result. The determination device 10 may also be equipped with a communication unit, and the information indicating the determination result may be notified to an external device via the communication unit, and the external device may execute a process using the determination result.

[0046] Figure 4 is a schematic diagram illustrating a specific arrangement example of camera 100, light source 200, and component 300. In the example shown in Figure 4, in a factory using white LED lighting, camera 100 and light source 200 emitting infrared light are supported on a support rail 700 fixed to a ceiling beam. The support rail 700 supports camera 100 and light source 200 via a support member that can move along the rail, allowing the positions of camera 100 and light source 200 to be changed as needed.

[0047] The support base 600 includes a plurality of support members 600a to 600c and positioning members 600d and 600e. A component 310 having a plurality of through holes 310a to 310c is placed on the support members 600a to 600c of the support base 600 and positioned in a predetermined location that contacts the plurality of positioning members 600d and 600e. The component 310 is fixed in the predetermined position by being positioned vertically by the support members 600a to 600c and horizontally by being positioned horizontally by the plurality of positioning members 600d and 600e. The number of positioning members and support members included in the support base 600 is not limited, and the positioning members and support members may be provided independently, or one member may serve as both a positioning member and a support fixing member.

[0048] As shown by the dashed arrows in Figure 4, part 310 is positioned so that the light irradiated from the light source 200 and passing through each of the through holes 310a to 310c is not reflected by the support members 600a to 600c and the positioning members 600d and 600e. In other words, the support base 600 is configured such that the support members 600a to 600c and the positioning members 600d and 600e do not block the optical path of the light irradiated from the light source 200 that has passed through each of the through holes 310a to 310c near the back surface of part 300.

[0049] For example, the component 310 is held in a position spaced apart from the floor and walls using the support base 600. Specifically, the support base 600 is used such that the distance traveled by light irradiated from the light source 200, passing through each through-hole 310a to 310c from the surface side of the component 300, before being reflected by an object such as the floor, wall, or part of the support base 600 on the back side of the component 300 is greater than or equal to a predetermined distance. As described above, the predetermined distance should be set so that the brightness value of the through-hole portion shown in each image is approximately the same for both the image with the light source on and the image with the light source off.

[0050] For example, in the example shown in Figure 4, the distance d1 between the lower surface of the component 310 and the reflective surface 600f of the support base 600 leg, which reflects light irradiated from the light source 200 and passing through the through holes 310b and 310c, is set to a distance such that almost all of the reflected light from the reflective surface 600f does not pass through the through holes 310a to 310c again. Similarly, the distance d2 to the reflective surface 701 of the wall that reflects light irradiated from the light source 200 and passing through the through hole 310a is also set to a distance such that almost all of the reflected light from the reflective surface 701 does not pass through the through holes 310a to 310c again. In other words, the distances d1 and d2 are set so that the pixel values ​​of the regions corresponding to each through hole 310a to 310c are approximately the same in the image captured by the camera 100 obtained with the light source 200 that emits infrared light turned on, and in the image captured by the camera 100 obtained with the light source 200 turned off.

[0051] Thus, the support base 600 that supports the component 310 is configured such that it does not block the optical path of the light irradiated from the light source 200 and passing through each through-hole 310a to 310c, and the optical path length after passing through each through-hole 310a to 310c satisfies predetermined conditions. For example, on the front and back surfaces of the component 310, the support members 600a to 600c and the positioning members 600d and 600e are arranged so as to avoid being within a predetermined distance from the outer circumference of each through-hole 310a to 310c. In addition, the support base 600 ensures a distance from each through-hole 310a to 310c to surrounding objects such as the floor, wall, and the legs of the support base 600.

[0052] Figure 5 shows an example of a specific part 320. In the part 320, a portion of which is shown in Figure 5, a through hole 320a is formed, depending on the specifications of the product in which the part 320 is used. The surface 320e of the part 320 includes through holes 320b and 320c, which are provided regardless of the product specifications, and structural parts 320d such as recesses and protrusions.

[0053] The hole presence / absence detection system 1 detects whether or not there is a through hole 320a in the part 320. For example, as explained in Figure 4, the part 320 is placed on a dedicated support stand, and the camera 100 acquires an off-light image taken with the light source 200 turned off, and an on-light image taken with the light source 200 turned on. The determination device 10 acquires a partial image by cutting out a portion of the area shown by the dashed rectangle in Figure 5 from the image of the part 320 taken by the camera 100, and determines whether or not there is a through hole 320a.

[0054] Figure 6 is a diagram illustrating an example of an image used by the determination device 10 for determination. For example, an infrared light transmission filter 101 that transmits light in the infrared region with a wavelength of 820 nm or more is attached to a camera 100 having a resolution of 1.3 megapixels, and a light source 200 that irradiates infrared light with a wavelength of 850 nm or more is turned on and off to obtain the light source on image 411 shown in Figure 6(a) and the light source off image 412 shown in Figure 6(b).

[0055] The on-light image 411 shown in Figure 6(a) is a bright image in which infrared light is reflected from the surface of component 320. In addition to the through-hole 320a that is to be judged, the on-light image 411 also shows through-holes 320b and 320c that are not to be judged, as well as irregularities caused by other structural parts 320d.

[0056] The light source off image 412 shown in Figure 6(b) is a dark image because it was taken under ambient light that contains almost no infrared light. In addition to the through holes 320a that are to be judged, the light source off image 412 also shows through holes 320c that are not to be judged, as well as irregularities caused by other structural parts 320d.

[0057] The determination device 10 generates a difference image 413 from the light source on image 411 and the light source off image 412. The light source on image 411 and the light source off image 412 are images with low contrast between the through hole 320a and the surrounding component surface, but as shown in Figure 6(c), the generated difference image 413 has improved contrast and is an image in which the through hole 320a is clearly visible.

[0058] The storage unit 12 of the determination device 10 stores template images 500, as shown in Figure 6(d), which are prepared in advance to correspond to the through-hole 320a. For example, the template image 500 can be prepared in advance by taking a difference image obtained by imaging a part 320 having a through-hole 320a, and then cutting out a rectangular area that includes the through-hole 320a and is slightly larger than the through-hole 320a.

[0059] The determination device 10 determines that if the difference image 413 contains a portion that matches the template image 500, then the part 320 has a through hole 320a; otherwise, it determines that the part 320 does not have a through hole 320a. The determination can be made based on the correlation coefficient calculated at each position while scanning the difference image 413 with the template image 500.

[0060] In the on-light image 411 shown in Figure 6(a), the area where the structural part 320d is imaged appears with the same brightness as the through-hole 320a. Therefore, if the presence or absence of the through-hole 320a is detected using the on-light image 411, the structural part 320d or a nearby area of ​​the component 320 that does not have a through-hole 320a may be mistakenly identified as the through-hole 320a. Similarly, if the presence or absence of the through-hole 320a is detected using the off-light image 412 shown in Figure 6(b), another area that is not the through-hole 320a may be mistakenly identified as the through-hole 320a. By using the difference image 413 shown in Figure 6(c) to detect the presence or absence of the through-hole 320a, such misidentifications can be prevented, and the presence or absence of the through-hole 320a can be determined with high accuracy.

[0061] The support base 600 shown in Figure 4 of this embodiment is just one example and does not limit the configuration of the support base 600. As described above, if the presence or absence of through holes can be determined from the image captured using the camera 100 and the light source 200, the support base 610 may be configured by a plurality of independent base parts 611 to 613, as shown in Figure 7(a). Alternatively, the support base 620 shown in Figure 7(c) may have a structure in which openings 620a are provided corresponding to one or more through holes. If the presence or absence of through holes can be determined simply by placing the component on the floor surface, as described above, a support base may not be used.

[0062] If indirect light emitted from the light source 200 and circling around from the outside to the back of the component affects the determination result, a shielding plate 650 may be provided as shown in Figure 7(b). As shown in Figure 7(c), a portion of the support base 620, 620b, may also function as a shielding plate. By installing the light source 200 so that it can illuminate the component on the support base 620 as shown by the solid arrow in Figure 7(c), and by shielding the indirect light from the light source 200 as shown by the dashed arrow, it is possible to determine whether or not there is a through hole in the component, as described above.

[0063] In this embodiment, an example of detecting the presence or absence of a through-hole using template matching technology with a template image has been described. However, the process of detecting the presence or absence of a through-hole includes the process of identifying the location of the through-hole on the captured image. As described above, when a difference image is generated between an image with the light source on and an image with the light source off, and the location of the through-hole is searched using this difference image, this implementation is included in the implementation of through-hole presence or absence detection by the hole presence / absence detection system 1. Note that the method for determining the presence and location of a through-hole on the difference image is not limited to the template matching method, but may also be the use of other methods such as edge detection, machine learning, or AI technology.

[0064] The configuration of the hole presence / absence detection system 1 shown in this embodiment is functionally schematic, and the configuration of the hole presence / absence detection system 1 is not physically limited to this configuration. The form of distribution and integration of each device is not limited to the example described above, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads and usage conditions.

[0065] While embodiments of the hole presence / absence detection system and hole presence / absence detection method according to this disclosure have been described above with reference to the drawings, the configuration and operation of the hole presence / absence detection system and each of its constituent devices are not limited to the above embodiments, and may be implemented with various improvements, changes, and modifications based on the knowledge of a person skilled in the art, without departing from the spirit of the invention. [Industrial applicability]

[0066] As described above, the hole presence / absence detection system and hole presence / absence detection method relating to this disclosure are useful for detecting the presence or absence of through holes in manufactured parts with high accuracy. [Explanation of Symbols]

[0067] 1. Hole presence / absence detection system 10 Judgment device 11 Control Unit 12 Storage section 13 Control section 14 Display section 100 Cameras 101 Filters 600, 610, 620 support stand

Claims

1. A hole presence / absence detection system for detecting the presence or absence of through holes in a component, A light source that emits light of a predetermined wavelength or wavelength range, which is set based on the light components contained in ambient light, A camera that images a component through a filter that blocks light outside a predetermined wavelength range including the wavelength of light emitted by the aforementioned light source, A determination device that determines the presence or absence of a through hole based on a difference image between a first image taken by the camera with the light source turned off and a second image taken by the camera with the light source turned on. Equipped with, The component is arranged such that the brightness value of the through-hole portion included in the first image is approximately the same as the brightness value of the through-hole portion included in the second image. A hole presence / absence detection system characterized by the following:

2. The hole presence / absence detection system according to claim 1, characterized in that the component is positioned so that indirect light irradiated from the light source and which wraps around from the outside of the component to the back side does not pass through the through hole of the component from the back side.

3. A shielding plate that blocks indirect light irradiated from the light source and that wraps around from the outside to the back side of the component. The hole presence / absence detection system according to claim 1, further comprising the features described above.

4. A support base that positions and supports the aforementioned component, and has a shape near the back surface of the component that does not block the optical path of light irradiated from the light source and passing through the through-hole of the component. The hole presence / absence detection system according to claim 1, further comprising the features described above.

5. The support base includes a support member that supports the component from the back side, The support member is positioned such that the light irradiated from the light source, passing through the through-hole from the surface side of the component and reflected by the support member on the back side, is not captured by the camera through the through-hole. The hole presence / absence detection system according to feature 4.

6. The hole presence / absence detection system according to claim 1, characterized in that the wavelength or wavelength range of the light irradiated from the light source is a wavelength or wavelength range in which the amount of light contained in the ambient light is small.

7. The hole presence / absence detection system according to claim 1, characterized in that the light emitted from the light source is infrared light of a predetermined wavelength or wavelength range.

8. A hole presence / absence detection method for detecting the presence or absence of through holes in a component, A step of turning off a light source that emits light of a predetermined wavelength or wavelength range set based on the light components contained in ambient light, and acquiring a first image of the component using a camera equipped with a filter that blocks light other than the predetermined wavelength range including the wavelength of light emitted by the light source, The process involves turning on the light source to irradiate the component with light and acquiring a second image of the component captured by the camera, A step to determine the presence or absence of a through hole based on the difference image between the first image and the second image. Includes, The component is arranged such that the brightness value of the through-hole portion included in the first image is approximately the same as the brightness value of the through-hole portion included in the second image. A method for detecting the presence or absence of holes, characterized by the features described above.

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