Image inspection device and image inspection method

Abstract

To provide an image inspection device and the like that enable effective inspection by using a plurality of images.SOLUTION: An image inspection device includes: an image acquisition unit that acquires a first image, which is a fragmentary image obtained by photographing an object to be inspected, and acquires a second image, which is a fragmentary image different from the first image, obtained by photographing the object to be inspected; an image composition unit that generates a composite image of the first or second image based on the corresponding fragmentary image; and an inspection unit that performs inspection based on the first and second images. The inspection unit performs inspection using the composite image of the first or second image.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an image inspection device and an image inspection method. [Background technology]

[0002] Patent Document 1 discloses an inspection method in which a container filled with a viscous material is irradiated with light from above and the presence or absence of shadows on the surface of the flange portion caused by protrusions on the surface of the viscous material near the flange portion inside the container is determined by imaging. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6070940 [Patent Document 2] Patent No. 7123816 Summary of the Invention [Problem to be solved by the invention]

[0004] However, depending on the inspection object or the inspection purpose, for example, by using a plurality of images with different illumination lights or shooting angles, an effective inspection may be possible.

[0005] Therefore, in one aspect, an object of the present disclosure is to provide an image inspection device and the like that enables effective inspection by using multiple images. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, an image acquisition unit that acquires a first image, which is a fragmentary image of an object to be inspected, and acquires a second image, which is a fragmentary image different from the first image, of the object to be inspected; an image synthesis unit that generates a synthesis image of the first image or the second image based on the corresponding fragment image; an inspection unit that performs an inspection based on the first image and the second image; Equipped with There is provided an image inspection device in which the inspection unit performs inspection using the composite image of the first image or the second image. Effect of the Invention

[0007] According to one aspect, the present disclosure can provide an image inspection device or the like that enables effective inspection by using a plurality of images. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of an inspection system including an image inspection device according to an embodiment of the present invention. [Diagram 2] 11A and 11B are front views illustrating an imaging method in the inspection system. [Figure 2A] 11 is a perspective view illustrating an imaging method in the inspection system. FIG. [Diagram 3] FIG. 2 is a diagram illustrating an example of an entire image obtained by scanning with a line camera. [Figure 4] 1 is a diagram illustrating an example of a first image obtained by scanning with a line camera. [Diagram 5] 13 is a diagram illustrating an example of a second image obtained by scanning with the line camera. FIG. [Figure 6] FIG. 2 is a schematic diagram of the container shown in the first image. [Figure 6A] A schematic diagram showing the contents shown in the second image. [Figure 7] FIG. 1 is a diagram illustrating the location of a container and the location of contents. [Figure 8] FIG. 2 is a diagram illustrating a composite image of the first image. [Figure 9] FIG. 2 is a diagram illustrating a composite image of the first image. [Figure 9A] 10 is a diagram conceptually showing a method for generating image fragments in the example of FIG. 9. FIG. [Figure 10]FIG. 13 is a diagram showing an example in which containers being transported by a conveyor are photographed by two line cameras arranged along the transport direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] FIG. 1 is a diagram showing the configuration of an inspection system equipped with an image inspection device of this embodiment, FIG. 2 is a front view illustrating an imaging method in the inspection system, and FIG. 2A is a perspective view illustrating the imaging method in the inspection system.

[0010] As shown in Figure 1, the inspection system is composed of an image inspection device 10 of this embodiment, a conveying control device 20 that controls a conveying device including a conveyor 21 (Figures 2 and 2A), and a main control device 100 that controls the image inspection device 10 and the conveying control device 20.

[0011] As shown in FIG. 1, the image inspection device 10 includes an image acquisition unit 10A that acquires a first image, which is a fragmentary image of a container 40 (FIGS. 2 and 2A) as an object to be inspected, and acquires a second image, which is a fragmentary image different from the first image, which is an image of the container 40; an image synthesis unit 10B that generates a composite image of the first image or the second image by synthesizing corresponding fragmentary images; and an inspection unit 10C that inspects the container 40 based on the first image and the second image, which include the composite image.

[0012] As shown in Fig. 1, an image acquisition unit 10A of an image inspection device 10 controls a line camera 11, a reflected light illumination unit 15, and a transmitted light illumination unit 16 to acquire a first image and a second image. The reflected light illumination unit 15 and the transmitted light illumination unit 16 illuminate a container 40 with reflected light illumination and transmitted light illumination, respectively. An image synthesis unit 10B of the image inspection device 10 performs image synthesis through image processing by an image processing device 12. An inspection unit 10C of the image inspection device 10 performs inspection of the container 40 using image processing by the image processing device 12.

[0013] In this embodiment, the container 40 is a container made of a plastic having optical transparency (transparent). For example, an inspection is performed by the inspection system while foodstuffs as the contents 45 are stored, and after the inspection is completed, the opening at the top of the container 40 is sealed with a top seal (not shown). If foodstuffs protrude onto the flange portion 43 (FIG. 6) at the top of the container 40, the foodstuffs will be pinched between the flange portion 43 and the top seal during sealing, resulting in so-called pinching (sealing failure). In this embodiment, the container 40 is inspected before the foodstuffs are stored and sealed. Therefore, it is possible to detect the container 40 with foodstuffs protruding onto the flange portion 43 (FIG. 6) before pinching actually occurs. Note that this embodiment is applicable to any method as a process for closing the opening at the top of the container 40. For example, it is also applicable to a case where the opening is closed with a lid. In addition, the material of the container is also arbitrary. For example, this embodiment is also applicable to a container such as glass.

[0014] As shown in Fig. 1, the transport control device 20 controls a motor 22 that drives a conveyor 21. As shown in Fig. 2 and Fig. 2A, the conveyor 21 transports containers 40 from left to right in Fig. 2.

[0015] 2 and 2A, a line camera 11 is fixedly installed above the conveyor 21 to capture images of the containers 40 transported at a constant speed by the conveyor 21. In addition, a reflected light illumination unit 15 is provided near the line camera 11 to illuminate the containers 40 from above.

[0016] In addition, a transmitted light illumination unit 16 is installed below the conveyor 21. Illumination light from the transmitted light illumination unit 16 is irradiated upward through a gap 25 formed in the conveyor 21, and illuminates the containers 40 transported by the conveyor 21.

[0017] 2 and 2A, the line camera 11, the reflected light illumination unit 15, and the transmitted light illumination unit 16 are disposed at the same position in the flow direction of the conveyor 21. That is, the reflected light illumination unit 15 and the transmitted light illumination unit 16 are provided facing each other in the vertical direction across the gap 25 of the conveyor 21, and the line camera 11 is disposed between the reflected light illumination unit 15 and the transmitted light illumination unit 16.

[0018] Next, the operation during shooting will be described.

[0019] When the container 40 containing the contents 45 is conveyed by the conveyor 21 and approaches the position of the gap 25, the line camera 11 starts taking pictures. In this embodiment, during a photographing period including a period during which the container 40 conveyed by the conveyor 21 passes the position of the gap 25, illumination light is alternately irradiated onto the container 40 from the reflected light illumination unit 15 and the transmitted light illumination unit 16. In addition, scanning by the line camera 11 is performed in accordance with the timing at which illumination light is irradiated from the reflected light illumination unit 15 and the transmitted light illumination unit 16. As a result, the image acquisition unit 10A acquires a first image of the container 40 captured by reflected light, and acquires a second image of the container 40 captured by transmitted light. That is, the first image and the second image are acquired by the image acquisition unit 10A at different times from each other.

[0020] 3 to 5 and 9, the vertical direction corresponds to the scanning direction of line camera 11, and the horizontal direction corresponds to the transport direction of conveyor 21.

[0021] As shown in Fig. 3, an image 50 obtained by scanning the line camera 11 includes a plurality of rectangular fragmentary images 51 constituting a first image, and a plurality of rectangular fragmentary images 52 constituting a second image. The fragmentary images 51 and 52 are arranged alternately in the left-right direction of Fig. 3. Here, the fragmentary images 51 and 52 are images corresponding to one scan of the line camera 11, respectively. That is, one fragmentary image 51 and one fragmentary image 52 are alternately acquired by the image acquisition unit 10A for each scanning period of the line camera 11.

[0022] In this disclosure, the fragmentary images refer to images corresponding to a part of the photographing range. In this embodiment, the fragmentary images 51 are a collection of images photographed with the light reflected by the reflected light illumination unit 15, and the fragmentary images 52 are a collection of images photographed with the light reflected by the transmitted light illumination unit 16.

[0023] FIG. 4 is a diagram illustrating a first image obtained by scanning with the line camera, and FIG. 5 is a diagram illustrating a second image obtained by scanning with the line camera.

[0024] As shown in Fig. 4, the first image does not include the entire photographed area of ​​the container 40, but only a portion of the area. As shown in Fig. 5, the second image includes only a portion of the photographed area of ​​the container 40 that is not included in the first image.

[0025] In addition, in Figs. 3 to 5 and 9, for convenience of explanation, the width (width in the horizontal direction in Figs. 3 to 5 and 9) and pitch (pitch in the horizontal direction in Figs. 3 to 5 and 9) of the fragment image 51 and the fragment image 52 are drawn larger than in reality. However, in reality, the width and pitch of the fragment image 51 and the fragment image 52 are limited to a degree that allows image inspection, which will be described later. This width and pitch depend on the resolution of the line camera 11, but may be, for example, about 1 to 10 pixels as the number of pixels in the line camera 11. In addition, depending on the shooting conditions, the conveying speed of the conveyor 21, the performance of the line camera 11, the operating cycle of the image inspection device 10, etc., there may be a period between the fragment image 51 and the fragment image 52 that cannot be shot. In such a case, the period (images) can be ignored, and only the fragment image 51 and the fragment image 52 that have been shot can be used.

[0026] FIG. 6 is a schematic diagram of the container shown in the first image.

[0027] 6, the shape of the container 40 is shown in a first image taken with reflected light. The shape of the transparent container 40 is presented more clearly in the image taken with reflected light than in the image taken with transmitted light.

[0028] In FIG. 6, the flange portion 43 of the container 40 is shown as a region surrounded by an outer contour 41 of the flange portion 43 and an inner contour 42 of the flange portion 43 .

[0029] 6, the flange portion 43 of the container 40 is illustrated as being annular, but the shape of the flange portion 43 is arbitrary. The flange portion 43 has a shape corresponding to the shape of the opening of the container 40. The shape of the opening of the container 40 can be exemplified as a rectangular shape, etc.

[0030] FIG. 6A is a schematic diagram of the contents shown in the second image.

[0031] As shown in Figure 6A, the shape or contour of the contents 45 is shown in the second image taken with transmitted light. The shape or contour of the opaque contents 45 is more clearly presented in the transmitted light image than in the reflected light image.

[0032] Thus, according to this embodiment, the position of container 40 is identified based on a first image of container 40 captured with reflected light, and the position of contents 45 is identified based on a second image of container 40 together with contents 45 captured with transmitted light. Therefore, the positions of container 40 and contents 45 can be detected stably.

[0033] Next, the process in the inspection unit 10C will be described.

[0034] The inspection unit can perform the inspection by comparing the position of the inspection object (container 40) in the composite image of the first image with the position of the inspection object (contents 45) in the composite image of the second image. Specifically, the inspection unit 10C identifies the position of the container 40 based on the first image, and identifies the position of the contents 45 based on the second image. Here, the position of the container 40 identified by the inspection unit 10C includes the area of ​​the flange portion 43, and the position of the contents 45 identified by the inspection unit 10C includes the area of ​​the contents 45. In this embodiment, the area of ​​the flange portion 43 is identified as the position of the container 40. Also, in this embodiment, the area of ​​the contents 45 as the position of the contents 45, particularly the presence or absence of the contents 45 in the area of ​​the flange portion 43, is identified.

[0035] In this case, the inspection unit 10C can detect the positions of the container 40 and the contents 45 by using the first image and the second image as they are. The inspection unit 10C can also detect the positions of the container 40 and the contents 45 by using a composite image of the first image or the second image generated by the image synthesis unit 10B. The inspection unit 10C may use one of the first image and the second image as it is, and detect the positions of the container 40 and the contents 45 by using the composite image of the other. The composite image generated by the image synthesis unit 10B will be described later.

[0036] Here, the first image and the second image have a common angle of view because they are images taken by the line camera 11 from the same position through the same lens. Therefore, the positions of the container 40 and the contents 45 can be identified as positions on a common coordinate system in the image 50.

[0037] Even if the first image does not include the entire area of ​​the flange portion 43, the inspection unit 10C can estimate (identify) the area of ​​the flange portion 43 based on an image of another area in another first image. Furthermore, if information related to the area of ​​the flange portion 43, for example, the shapes of the container 40 and the flange portion 43, is known, the inspection unit 10C can estimate (identify) the area of ​​the flange portion 43 by further using this information.

[0038] FIG. 7 is a diagram illustrating the location of the container and the location of the contents.

[0039] In the example of Fig. 7, in region 60, the contents 45 have entered the region of the flange portion 43 of the container 40. In other words, the contents 45 have climbed up onto the flange portion 43, and in such a case, the inspection unit 10C judges the storage state to be defective. If it is judged to be defective, the container 40 is removed from the transport path to the top seal sealing process under the control of the transport control device 20, and is sent again to the process of storing the contents 45. If the contents 45 have not entered the region of the flange portion 43 of the container 40, the inspection unit 10C judges the storage state to be good, and the container 40 is transported to the top seal sealing process under the control of the transport control device 20.

[0040] Next, the process in the image synthesis unit 10B will be described.

[0041] The image synthesis unit 10B generates a synthesis image of the first image or the second image based on the first image or the second image.

[0042] In the following description, a composite image of the first image is exemplified, but it is possible to generate a composite image of the second image by the same process. However, it is considered more effective to apply this to the first image, which is an image of the container 40 that does not show abrupt changes in the conveying direction of the conveyor 21, compared to the image of the content 45.

[0043] As described above, the composite image generated by the image composition unit 10B is used in the inspection by the inspection unit 10C.

[0044] 8 and 9 are diagrams illustrating a composite image of the first image.

[0045] In the example of FIG. 8, the image synthesis unit 10B generates a synthesized image 50A of the first image by interpolating image fragments 51a in an area where no image fragment 51 exists in FIG.

[0046] In Fig. 8, the reference numbers "1" to "7" attached to the image fragment 51 indicate the image of the image fragment 51, and the same reference numbers indicate the same image. That is, in the example of Fig. 8, the image synthesis unit 10B generates a synthetic image 50A by sequentially arranging image fragments 51a of the same image as the image fragment 51 next to the image fragment 51.

[0047] On the other hand, in the example of FIG. 9, the image synthesis unit 10B generates a synthesized image 50B of the first image by interpolating an image fragment 51b, which is an intermediate image, in an area where no image fragment 51 exists in FIG.

[0048] FIG. 9A is a diagram conceptually showing a method for generating an intermediate image.

[0049] 9A, an image fragment 51b corresponds to an intermediate image between adjacent image fragments 51 on both sides of the image fragment 51. For example, an image of image fragment 51b can be generated such that the positions of the contours shown in the adjacent image fragments 51 are continuously changed by the image fragment 51b inserted therebetween, and the contours shown in the adjacent image fragments 51 are connected to each other.

[0050] The image synthesis unit 10B sequentially generates image fragments 51b corresponding to such intermediate images, and generates a synthesized image 50B of the first image by interpolating the image fragments 51b into areas where no image fragments 51 exist.

[0051] FIG. 10 is a diagram showing an example in which containers being transported on a conveyor are photographed by two line cameras arranged along the transport direction.

[0052] As shown in Fig. 10, a line camera 11A for photographing containers 40 transported at a constant speed by the conveyor 21 is installed above the conveyor 21 on the upstream side of the conveyor 21. In addition, a reflected light illumination unit 15A for surface-illuminating the containers 40 from above is provided near the line camera 11A. As shown in Fig. 10, the line camera 11A and the reflected light illumination unit 15A are arranged at the same position in the flow direction of the conveyor 21.

[0053] Meanwhile, downstream of the conveyor 21 with respect to the line camera 11A, a line camera 11B is installed above the conveyor 21 for photographing the containers 40 transported at a constant speed by the conveyor 21. Also, a transmitted light illumination unit 16B is installed below the conveyor 21. Illumination light from the transmitted light illumination unit 16B is irradiated upward through a gap 25B formed in the conveyor 21, illuminating the containers 40 transported by the conveyor 21. As shown in FIG. 10, the line camera 11B, the transmitted light illumination unit 16B, and the gap 25B are arranged at the same position in the flow direction of the conveyor 21.

[0054] In the configuration of Fig. 10, the image acquisition unit 10A acquires a first image via a line camera 11A installed on the upstream side of the conveyor 21. In this case, the first image may be an image of the entire container 40 captured by the line camera 11A, or may be a fragmentary image as shown in Fig. 4. For example, when the transport speed of the conveyor 21 is faster than the scanning period of the line camera 11A, the first image is a fragmentary image.

[0055] Similarly, image acquisition unit 10A acquires a second image via line camera 11B installed downstream of conveyor 21. In this case, the second image may be an image of container 40 and contents 45 captured in its entirety by line camera 11B, or may be a fragmentary image as shown in Fig. 5. For example, when the transport speed of conveyor 21 is faster than the scanning period of line camera 11B, the second image is a fragmentary image.

[0056] When the first image or the second image is a fragmentary image, the fragmentary image can be subjected to the above-mentioned image synthesis process by the image synthesis unit 10B.

[0057] 10, the content 45 may be stored in the container 40 between the positions of the line cameras 11A and 11B. In this case, the empty container 40 can be photographed via the line camera 11A. Therefore, the container 40 is not hidden by the content 45 in the first image, and the entire container 40 can be photographed.

[0058] In the configuration of FIG. 10, the inspection unit 10C also identifies the area of ​​the flange portion 43 of the container 40 based on the first image, and identifies the area of ​​the contents 45 based on the second image. In addition, as shown in FIG. 7, when the contents 45 ride up on the flange portion 43, the inspection unit 10C judges the storage state to be defective. However, in the configuration of FIG. 10, the line camera 11A that captures the first image and the line camera 11B that captures the second image are installed at locations away from each other, and the capture range and capture timing are also set individually. Therefore, a positioning process is required to match the position of the container 40 identified based on the first image with the position of the contents 45 identified by the second image. This process is executed, for example, by the inspection unit 10C via the image processing device 12. For example, a process (positioning process) may be performed in which a plurality of marks that are visible in reflected light and transmitted light are attached to the container 40, and the positions of these marks are matched in the first image and the second image. In the present disclosure, only one of the first image and the second image may be a fragmentary image, and the other may be an image of the entire object to be inspected. For example, in the example of FIG. 10, the image capturing using reflected light with the line camera 11A can be completed in one go, but the image capturing using transmitted light with the line camera 11B needs to be performed multiple times because the transmitted light passes only through the gap 25B of the conveyor 21. In such a case, in one case (image capturing using transmitted light), a composite image may be generated after a fragmentary image is captured, and in the other case (image capturing using reflected light), an image of the entire object to be inspected (container 40) captured in one go may be used. That is, in the example of FIG. 10, the entire object to be inspected (container 40) may be captured using reflected light with the line camera 11A, and then the object to be inspected (container 40) may be transported at a constant speed while being captured using transmitted light to obtain fragmentary images, and a composite image may be generated.

[0059] In the present disclosure, the first image and the second image are not limited to a combination of an image taken by reflected light and an image taken by transmitted light. For example, both the first image and the second image may be images taken by reflected light, or both the first image and the second image may be images taken by transmitted light. There may be a difference in the photographing conditions between the first image and the second image.

[0060] Examples of differences in shooting conditions include the intensity of illumination light, the intensity of exposure, differences in shooting range, differences in shooting position, differences in shooting angle, and the like.

[0061] For example, when the object to be inspected has contrast, a first image and a second image taken from cameras installed at symmetrical positions may be compared. In this case, a defect in the object to be inspected can be detected based on the lack of contrast or identity of the images. When taking pictures with multiple cameras installed at symmetrical positions, the image taken by one camera may affect the image taken by the other camera, for example, when taking pictures using a flash. In this case, it is preferable to prevent the image taking timing of the two cameras from overlapping. For example, this applies to the case where multiple cameras are installed close to each other and the example of FIG. 10. In addition, in order to obtain a clear image, it is sometimes necessary to photograph the details of the photographed object (inspection object). In this case, it is necessary to bring the camera close to the photographed object and photograph each part of the photographed object, and the work of photographing and shifting the photographing position is repeated. However, repeating such a work takes time. The technology disclosed herein is useful for shortening the time while obtaining a clear image. Specifically, for example, cameras can be placed on both sides of the object to be photographed, and the positions of both cameras can be shifted while photographing alternately at non-overlapping times. In this case, since each camera is moved to photograph intermittently, there will be some parts that are not photographed. However, according to the present disclosure, by creating a composite image based on the fragmentary images, it is possible to perform an effective inspection even if there are some parts that are not photographed.

[0062] As described above, according to this embodiment, a first image, which is a fragmentary image of an object to be inspected, and a second image, which is a fragmentary image different from the first image, are acquired, and inspection is performed based on the first image and the second image. In this way, by using multiple images, effective inspection is possible.

[0063] Although each embodiment has been described above in detail, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. In addition, it is also possible to combine all or a plurality of the components of the above-described embodiments. [Explanation of symbols]

[0064] 10. Image inspection equipment 10A Image acquisition unit 10B Image synthesis section 10C Inspection Department 11 Line Camera 12 Image processing device 15 Reflected light lighting section 16 Illumination section for transmitted light 21 Conveyor 40 containers 45 Contents

Claims

1. an image acquisition unit that acquires a first image, which is an image of an object to be inspected, and acquires a second image, which is an image of the object to be inspected and is a fragmentary image different from the first image; an image synthesis unit that generates a synthesis image of the second image based on the corresponding fragment image; an inspection unit that performs an inspection based on the first image and the second image; Equipped with The inspection unit performs inspection using the composite image of the second image.

2. The image inspection device of claim 1, wherein the first image and the second image are fragmentary images captured by a common camera while switching between reflected light illumination and transmitted light illumination of the object to be inspected being transported by a transport device.

3. The image inspection device according to claim 1 , wherein the first image and the second image are fragmentary images of the object to be inspected being transported by a transport device, each captured by two cameras installed at different positions.

4. 4. The image inspection device according to claim 1, wherein the image synthesis unit generates the synthetic image by performing interpolation using the image fragments.

5. 4. The image inspection device according to claim 1, wherein the image synthesis unit generates the synthetic image by performing interpolation using intermediate images generated based on the image fragments.

6. The inspection object is transported at a constant speed, the image acquisition unit acquires the first image and the second image, which are fragmentary images, at different times from each other; The image inspection device according to claim 1 , wherein the inspection unit performs the inspection by comparing a position of an object in the composite image of the first image with a position of an object in the composite image of the second image.

7. an image acquiring step of acquiring a first image which is a fragmentary image of an object to be inspected, and acquiring a second image which is a fragmentary image different from the first image of the object to be inspected; an image synthesis step of generating a synthesis image of the first image or the second image based on the corresponding fragment image; An inspection step of performing an inspection based on the first image and the second image; Equipped with An image inspection method, wherein in the inspection step, inspection is performed using the composite image of the first image or the second image.

Images