JP2024024524A - Inspection device and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection device and the like that can ensure a wide inspection range.

SOLUTION: An inspection device includes: an image acquisition unit that acquires an image in which a first target object having light transmissivity and a second target object to be photographed in a state where the first target object is interposed between a camera and the second target object are simultaneously photographed; a mask generation unit that generates a mask based on a contour of the second target object and a contour of the first target object in the image; and an inspection unit that performs image inspection in an area of the image that is narrowed down by the mask. The image acquisition unit acquires a reflected light image photographed with reflected light and a transmitted light image photographed with transmitted light, and the mask generation unit generates the mask based on the contour of the first target object obtained based on the reflected light image and the contour of the second target object obtained based on the transmitted light image.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure relates to an inspection device and an inspection method.

Patent Document 1 discloses a technique for inspecting the end of a bag containing contents.

Japanese Patent Application Publication No. 2013-007597

However, in the above technique, a region that is contracted by the width of the seal portion with respect to the contour of the bag is used as a mask. For this reason, only the end portion (sealed portion) of the bag is subject to inspection, making it impossible to inspect a wide range of the bag and its contents.

Therefore, in one aspect, the present disclosure aims to provide an inspection device and the like that can secure a wide inspection range.

According to one aspect of the present disclosure,
A first object having light transparency and the second object, which is photographed with the first object interposed between the camera and the second object, are photographed at the same time. an image acquisition unit that acquires an image;
a mask generation unit that generates a mask based on the outline of the second object and the outline of the first object in the image;
an inspection unit that performs an image inspection on a region of the image narrowed down by the mask;
An inspection device is provided.

In the above aspect, preferably, the image acquisition unit acquires a reflected light image photographed using reflected light and a transmitted light image photographed using transmitted light,
The mask generation unit generates the mask based on a contour of the first object obtained based on the reflected light image and a contour of the second object obtained based on the transmitted light image. do.

In the above aspect, preferably, the mask masks a region corresponding to the second target object and a region not corresponding to the first target object.

In the above aspect, preferably, the mask masks a region that does not correspond to the second object.

In the above aspect, preferably, the image acquisition unit includes a mask image as the image used in the mask generation unit and an inspection image as the image to be subjected to image inspection in the inspection unit. Then, an image under different photographing conditions from the mask image is acquired.

In the above aspect, preferably, the first object is a package, and the second object is the contents contained in the package.

According to one aspect of the present disclosure,
an image acquisition step of acquiring an image in which a first object having light transparency and a second object photographed through the first object are simultaneously photographed;
a mask generation step of generating a mask based on the contour of the second object or the contour of the first object in the image;
an inspection step of performing an image inspection on a region narrowed down by the mask in the image;
An inspection method is provided, comprising:

In one aspect, according to the present disclosure, a wide inspection range can be ensured.

1 is a diagram illustrating an example of the configuration of an inspection system including an inspection apparatus according to the present embodiment. It is a flow chart showing main processing in an inspection system. 3 is a flowchart showing image acquisition and masking processing. It is a flow chart showing image inspection processing. It is a figure which illustrates the image acquired in step S106. FIG. 7 is a diagram showing a mask generated and saved in step S108. It is a figure which illustrates the image acquired in step S116. It is a figure which shows the mask saved in step S118. It is a figure which illustrates the image acquired in step S126. It is a figure which shows the image obtained in step S128. It is a figure which illustrates the test result displayed in step S204. It is a figure which illustrates the mask of other shapes. It is a figure which shows the illumination device for photographing an inspection object, and other specific structural examples. It is a figure which shows the illumination device for photographing an inspection object, and other specific structural examples. It is a figure which shows the illumination device for photographing an inspection object, and other specific structural examples.

Examples will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an example of the configuration of an inspection system including the inspection apparatus of this embodiment.

As shown in FIG. 1, the inspection system includes an inspection apparatus 10 of the present embodiment, a control device 20 that executes control related to inspection, and a reflected light illumination device that illuminates an inspection object 50 (not shown in FIG. 1). 31 and a transmitted light illumination device 32, a camera 33 for photographing the inspection object 50, a conveyance device 40 for conveying the inspection object 50, and a display device 15. As shown in FIG. 1, the inspection device 10, the reflected light illumination device 31, the transmitted light illumination device 32, the camera 33, the transport device 40, and the display device 15 are controlled by a control device 20.

As shown in FIG. 1, the inspection device 10 includes an image acquisition unit 11 that acquires an image of an inspection target 50 taken by a camera 33 via a control device 20, and a mask based on the image acquired by the image acquisition unit 11. and an inspection unit 13 that performs an image inspection on the area narrowed down by the mask among the images acquired by the image acquisition unit 11 and inspects the quality of the inspection target 50. .

Next, the operation of the inspection system will be explained.

FIG. 2 is a flowchart showing main processing in the inspection system, FIG. 2A is a flowchart showing image acquisition and masking processing, and FIG. 2B is a flowchart showing image inspection processing.

In step S10 in FIG. 2, the control device 200 controls the transport device 40 to transport the inspection object 50 to a predetermined photographing position by the camera 33.

In step S100 in FIG. 2, image acquisition and masking processing are performed under the control of the control device 200.

As shown in FIG. 2A, in step S102 of the image acquisition and masking process (step S100), the control device 200 sets the reflected light illumination device 31 to ON and the transmitted light illumination device 32 to OFF. Note that the configurations of the reflected light illumination device 31 and the transmitted light illumination device 32 are arbitrary, but for example, LED devices can be used as the reflected light illumination device 31 and the transmitted light illumination device 32.

In step S104, the control device 200 sets the exposure amount of the camera 33 to a normal value.

In step S<b>106 , the control device 200 executes photography with the camera 33 and acquires the image of the inspection object 50 photographed with the camera 33 via the image acquisition unit 11 . Here, an image of the inspection object 50 photographed using reflected light is acquired.

FIG. 3 is a diagram illustrating an image acquired in step S106.

In the example of FIG. 3, a tray 52 (contents; second object) with relatively low light transmittance is placed inside a light-transparent resin bag 51 (packaging; first object); Food 53 (contents) placed on the tray 52 is accommodated. By selecting the reflected light illumination and setting the exposure amount of the camera 33 to a normal value, an image in which the outline of the resin bag 51 can be recognized can be obtained. The tray 52 and the food 53 are photographed by the camera 33 with the bag 51 interposed between them. Note that the amount of exposure of the camera 33 may be set to a value that makes it easy to recognize the outline of the bag 51.

In step S108, the control device 200 generates the mask 51A via the mask generation unit 12 and stores it.

FIG. 3A is a diagram showing the mask generated and saved in step S108.

As shown in FIG. 3A, the mask generation unit 12 recognizes the outline of the bag 51 based on the image acquired in step S106, generates a mask 51A that masks the outside of the outline of the bag 51, and stores it. As shown in FIG. 3A, the mask 51A has a shape with the outline of the bag 51 as its inner peripheral end, and masks an area that does not correspond to the bag 51. The region that does not correspond to the bag 51 (first object) refers to the region in the image acquired in step S106 where the bag 51 does not exist (in FIG. 3A, the region outside the outline of the bag 51).

Next, in step S112, the control device 200 turns off the illumination device 31 for reflected light and turns on the illumination device 32 for transmitted light.

In step S114, the control device 200 sets the exposure amount of the camera 33 to a value higher than the above-mentioned normal value.

In step S<b>116 , the control device 200 executes photography with the camera 33 and acquires the image of the inspection object 50 photographed with the camera 33 via the image acquisition unit 11 . Here, an image of the inspection object 50 photographed using transmitted light is acquired.

FIG. 4 is a diagram illustrating an image acquired in step S116.

In the example of FIG. 4, an image in which the outline of the tray 52 can be recognized is obtained by selecting transmitted light illumination and setting the exposure amount of the camera 33 to a value higher than the normal value. Also here, the tray 52 and the food 53 are photographed by the camera 33 with the bag 51 interposed between the tray 52 and the food 53. Note that the exposure amount of the camera 33 may be set to a value that makes it easy to recognize the outline of the tray 52.

In step S118, the control device 200 generates the mask 52A (FIG. 4A) via the mask generation unit 12 and stores it together with the mask 51A.

FIG. 4A is a diagram showing the mask saved in step S118.

As shown in FIG. 4A, the mask generation unit 12 recognizes the outline of the tray 52 based on the image acquired in step S116, generates a mask 52A that masks the inside of the outline of the tray 52, and stores it. As shown in FIG. 4A, the mask 52A has a shape whose outer peripheral end is the outline of the tray 52, and masks an area corresponding to the tray 52. As can be seen by comparing FIG. 3 and FIG. 4A, the area extracted by the mask 51A generated in step S108 and the mask 52A generated in step S118 is between the outline of the bag 51 and the outline of the tray 52. This is the area between.

Next, in step S122, the control device 200 turns off the illumination device 31 for reflected light and turns on the illumination device 32 for transmitted light.

In step S124, the control device 200 sets the exposure amount of the camera 33 to a value lower than the above-mentioned normal value.

In step S<b>126 , the control device 200 executes photography with the camera 33 and acquires the image of the inspection object 50 photographed with the camera 33 via the image acquisition unit 11 . Here, an image of the inspection object 50 photographed using transmitted light is acquired.

FIG. 5 is a diagram illustrating an image acquired in step S126.

In the example of FIG. 5, by selecting transmitted light illumination and setting the exposure amount of the camera 33 to a value lower than the normal value, the area sandwiched between the outline of the bag 51 and the outline of the tray 52 is This makes it easier to recognize the condition of the bag 51 (defects, etc.) reflected in the image. Note that the amount of exposure of the camera 33 may be set to a value that makes it easy to recognize the state of the bag 51.

In step S128, the control device 200 masks the image acquired in step S126 using the mask 51A and mask 52A stored in step S118 via the mask generation unit 12, and returns.

FIG. 5A is a diagram showing an image obtained in step S128.

As shown in FIG. 5A, in step S128, only the area sandwiched between the outline of the bag 51 and the outline of the tray 52 is extracted by masking the image acquired in step S126 with the mask 51A and the mask 52A. Ru.

Next, in step S200 (FIG. 2), image inspection processing is performed under the control of the control device 200.

As shown in FIG. 2B, in step S202 of the image inspection process (step S200), the control device 200 performs an image inspection on an area sandwiched between the outline of the bag 51 and the outline of the tray 52 via the inspection unit 13. do.

In step S204, the control device 200 displays the results of the image inspection (step S202) by the inspection unit 13 on the display device 15.

FIG. 6 is a diagram illustrating the test results displayed in step S204.

In the example of FIG. 6, the quality of the bag 51 as an inspection result is displayed, and for example, a mark 61 indicating poor appearance is displayed in an area where a poor appearance is found. Further, a mark 62 indicating this fact is displayed in an area where no appearance defect is recognized.

The area to be inspected (the area where the mark 61 or mark 62 is to be displayed) can be recognized based on the outline of the bag 51, that is, the inner peripheral end of the mask 51A.

Although the content of the inspection is arbitrary, for example, the presence or absence of defects in the welded portion of the bag 51 (insufficient welding, misalignment of the welded portion, holes in the welded portion, etc.) can be inspected. Furthermore, if there is a printed part on the bag 51, it is possible to inspect whether or not there is any printing misalignment. Furthermore, the presence or absence of foreign matter can also be inspected.

Furthermore, the inspection method by the inspection unit 13 is also arbitrary. For example, the inspection unit 13 may be made to learn a certain number of images in which the presence or absence of defects is determined by a person and the determination results are labeled. When determining the presence or absence of a defect using a learning model constructed through such learning, it is possible to determine the presence or absence of a defect based on criteria similar to human senses. Furthermore, by increasing the number of images to be studied, the accuracy of the determination is improved.

Next, in step S206, the control device 200 controls the transport device 40 (FIG. 1) to transport the inspected object 50 to a predetermined transport destination, and then returns. At this time, by switching the conveyance destination of the inspection object 50 according to the result of the image inspection (step S202) by the inspection unit 13, it is possible to separate non-defective products and defective products, for example.

In this way, in this embodiment, the mask 51A and the mask 52A are generated based on the outline of the bag 51 and the outline of the tray 52, so the inspection of the bag 51 can be performed over the entire area of the bag 51 where the tray 52 is not present. can do. That is, it becomes possible to test the test object 50 over a wide range.

Furthermore, in this embodiment, the mask 51A is generated based on the image obtained by photographing using reflected light, and the mask 52A is generated based on the image obtained by photographing using transmitted light. That is, reflected light photography and transmitted light photography are used to capture images for generating the masks 51A and 52A. Therefore, the contrast of pixel values in the image can be optimized between the regions of the masks 51A, 52A and other regions, and as a result, the masks 51A, 52A can be generated reliably and accurately. That is, in this embodiment, in reflected light photography, the contrast is adjusted so that the outline of the bag 51 becomes clear, and in transmitted light photography, the contrast is adjusted so that the range (outline) of the tray 52 becomes clear. I can do it. Since multiple imaging methods are used to clarify the masking range for each of the masks 51A and 52A, by combining the masks 51A and 52A, it is possible to reliably create a mask with a shape that combines both. Can be generated. Furthermore, since the exposure amount of the camera 33 is optimized when taking images for generating the masks 51A and 52A (reflected light photography and transmitted light photography), the contrast described above is further optimized.

In addition, in this embodiment, after the inspection object 50 is conveyed to a predetermined imaging position by the camera 33, the camera 33 performs an image capture process, including capturing images for generating the masks 51A and 52A without moving the inspection object 50. Shooting is being performed multiple times. Therefore, the area of the image in all of the plurality of images is constant with respect to the inspection object 50. Thereby, it is possible to eliminate the possibility that the positions of the mask 51A and the mask 52A will shift in the images (FIGS. 5A and 6) to be subjected to the image inspection (step S202) by the inspection unit 13. Therefore, it is possible to easily obtain images (FIGS. 5A and 6) in which the correct positions of the masks 51A and 52A are ensured, while eliminating the need for image processing to correct image misalignment.

In this embodiment, in the image inspection by the inspection unit 13 (step S202), the image for detecting appearance defects of the bag 51 is based on reflected light photography (step S122). Furthermore, the exposure amount of the camera 33 is set to a relatively low value so that defects in the appearance of the bag 51 can be easily recognized (step S124). However, the illumination method and exposure amount can be selected as appropriate depending on the type of inspection object 50, appearance defects, and other types of quality inspection. For example, transmitted light photography may be selected. Further, the wavelength and color of the illumination light are also arbitrary; for example, infrared light or ultraviolet light may be used, or illumination light of a specific color (wavelength band) may be used. Further, for example, the exposure amount may be any value that makes it easy to recognize a defect, and for example, a plurality of exposure amounts may be combined. Note that the exposure amount of the camera 33 can be controlled by the substantial exposure time of the camera 33, but may also be controlled by the intensity of illumination light.

In this example, in order to obtain an image for generating the mask 51A, an image for generating the mask 52A, and an image for image inspection of the bag 51, three images are taken under different imaging conditions. (Step S106, Step S116 and Step S126). However, if the images can be shared, the number of times the images are taken may be reduced. For example, if the image for generating the mask 51A and the image for image inspection of the bag 51 can be shared, the number of times of imaging can be reduced to two.

In the present invention, the area to be masked can be set arbitrarily. For example, it is also possible to generate a mask corresponding to inspection of an area where the bag 51 and the contents overlap.

FIG. 7 is a diagram illustrating a mask having another shape.

In FIG. 7, a mask 55 masks an area sandwiched between the outline of the bag 51 and the outline of the tray 52. Although the method for generating the mask 55 is arbitrary, for example, the mask 55 may be generated by generating a mask having a shape that is a combination of a mask 51A and a mask 52A as shown in FIG. 4A, and then inverting the combined mask. I can do it. By using such a mask 55, it is possible to inspect an area where the bag 51 and the contents (tray 52 and food 53) overlap. That is, unlike the case where a mask having the shape shown in FIG. 4A is used, by using the mask 55, it is possible to perform an image inspection focused only on the central portion of the bag 51. The inspection in this case may be an inspection of the bag 51 in the area, or an inspection of the contents, that is, the food 53 or the tray 52. Further, in this case, since the outer peripheral edge of the mask 55 corresponds to the outline of the bag 51, the position of the bag 51 within the region can be recognized with the outer peripheral edge of the mask 55 as a reference. For example, when it is desired to inspect a specific area 51a of the bag 51 shown in FIG. 7, the specific area 51a can be recognized using the outer peripheral edge of the mask 55 as a reference. Similarly, the position of the tray 52 within the area can be recognized with the inner peripheral end of the mask 55 as a reference. If it is desired to inspect the welded portion of the bag 51, coordinates indicating the position of the welded portion relative to the outline of the bag 51 can be prepared. In this case, it becomes easier to identify the region of the welded portion (for example, the region portion 51a) by relying on the position (the coordinates) based on the outer peripheral edge of the mask 55.

8 to 8B are diagrams showing an illumination device for photographing the inspection object and other specific configuration examples.

In the example of FIG. 8, a ring-shaped illumination device 31 for reflected light and a planar illumination device 32 for transmitted light are used. The object to be inspected 50 is placed on a belt 41 that is provided on the conveying device 40 and is capable of conveying the object to be inspected in the lateral direction. The inspection object 50 is photographed by a camera 33 fixedly installed above the belt 41 with the belt 41 stationary. The illumination light from the reflected light illumination device 31 illuminates the inspection object 50 from above. The belt 41 is transparent to the illumination light from the transmitted light illumination device 32, and the illumination light from the transmitted light illumination device 32 passes through the belt 41 and the inspection object 50 and heads upward. Note that infrared light may be selected as the illumination light of the transmitted light illumination device 32 in consideration of the transmittance to the belt 41.

In the example of FIG. 8A, the camera 33 is fixedly installed below the belt 41 of the conveyance device 40. Further, a ring-shaped illumination device 31 for reflected light is installed below the belt 41, and a flat illumination device 32 for transmitted light is installed above the belt 41, respectively. In this case, since both the reflected light and the transmitted light need to pass through the belt 41, it is desirable that the belt 41 be made of a member that is transparent to visible light.

In the example of FIG. 8B, the conveying device 40 is provided with a slit 42 that divides the belt 41 in the left-right direction, and the inspection object 50 is photographed by the camera 33 through the slit 42. In this case, the reflected light and the transmitted light pass through the slit 42, and the belt 41 is hardly involved in the image taken by the camera 33. Therefore, the belt 41 is not required to have light transmittance, and therefore, the belt 41 can be made of any material.

Further, instead of installing the camera 33 in a fixed manner, the camera 33 may be installed so as to be movable in parallel in the same direction as the belt 41. In this case, since the positional relationship between the camera 33 and the inspection object 50 can be fixed, it becomes possible to take pictures with the camera 33 while conveying the inspection object 50 by the belt 41.

Note that the form and shape of the reflected light illumination device 31 and the transmitted light illumination device 32 are arbitrary, and are not limited to the examples shown in FIGS. 8 to 8B. Furthermore, when the inspection object 50 is inspected at a position that is not affected by environmental light, the accuracy of inspection can be further improved.

As explained above, according to the above embodiment, since the mask 51A and the mask 52A are generated based on the outline of the bag 51 and the outline of the tray 52, the entire area of the bag 51 where the tray 52 does not exist is covered with the bag. 51 tests can be carried out. That is, it becomes possible to test the test object 50 over a wide range.

Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes can be made within the scope of the claims. It is also possible to combine all or a plurality of the components of the embodiments described above.

10 Inspection device 11 Image acquisition section 12 Mask generation section 13 Inspection section 15 Display device 20 Control device 31 Illumination device for reflected light 32 Illumination device for transmitted light 33 Camera 40 Conveyance device 51 Bag 52 Tray

Claims (7)

A first object having light transparency and the second object, which is photographed with the first object interposed between the camera and the second object, are photographed at the same time. an image acquisition unit that acquires an image;
a mask generation unit that generates a mask based on the outline of the second object and the outline of the first object in the image;
an inspection unit that performs an image inspection on a region of the image narrowed down by the mask;
An inspection device comprising: The image acquisition unit acquires a reflected light image taken using reflected light and a transmitted light image taken using transmitted light,
The mask generation unit generates the mask based on a contour of the first object obtained based on the reflected light image and a contour of the second object obtained based on the transmitted light image. The inspection device according to claim 1. The inspection device according to claim 1, wherein the mask masks a region corresponding to the second target object and a region not corresponding to the first target object. The inspection device according to claim 1, wherein the mask masks an area that does not correspond to the second object. The image acquisition unit is configured to obtain a mask image as the image used in the mask generation unit, and an inspection image as the image to be subjected to image inspection in the inspection unit, the mask image and The inspection device according to claim 1, which acquires images under different imaging conditions. The inspection device according to any one of claims 1 to 5, wherein the first object is a package, and the second object is contents contained in the package. an image acquisition step of acquiring an image in which a first object having light transparency and a second object photographed through the first object are simultaneously photographed;
a mask generation step of generating a mask based on the contour of the second object or the contour of the first object in the image;
an inspection step of performing an image inspection on a region narrowed down by the mask in the image;
An inspection method comprising: