JP7794780B2 - Inspection Equipment - Google Patents

Description

The present invention relates to an inspection device.

A conventional inspection device that uses an imaging device to inspect workpieces is described in Non-Patent Document 1. In the visual inspection process, the inspection device described in Non-Patent Document 1 captures images of the workpieces being transported using a camera installed above the conveyor that transports the workpieces, and determines whether the product is defective based on the captured images.

“Monthly Food Factory Manager” Nihon Shokuryo Shimbun, August 1, 2021, p.84-85

By the way, there are several types of conveyors that transport workpieces, each with a different width in the direction perpendicular to the transport direction, to accommodate workpieces of different sizes.

In the inspection device described in Non-Patent Document 1, the following issues arise when using the same camera to handle multiple types of conveyors with different widths, as described above.

With the inspection device described in Non-Patent Document 1, when changing to a conveyor of a different width from the one previously in use, the camera's imaging range must be changed to match the new conveyor width, so the camera's installation position relative to the conveyor and the lens must be adjusted.

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide an inspection device that can accommodate multiple types of conveying sections with different widths in the direction perpendicular to the conveying direction, without requiring adjustment of the installation position of the imaging device or the imaging lens.

The inspection device of the present invention is an inspection device that inspects an inspection item as it passes between a first conveying section and a second conveying section that are arranged with a predetermined gap between them in the conveying direction of the inspection item, and is equipped with an imaging device that is provided on one side of the predetermined gap in a transverse direction that intersects the conveying direction of the inspection item and images the inspection item from that side, and the imaging device is composed of a contact image sensor that integrates a light source, an imaging element, and an imaging lens, and the first conveying section and the second conveying section are configured to be replaceable with ones having a different conveying width, which is the width in a direction perpendicular to the conveying direction, and the contact image sensor is replaceable with one having a length that corresponds to the changed conveying width by the replacement, and is attached by a bracket (11) in a position where the distance to the inspection item does not change before and after the replacement .

With this configuration, the inspection device of the present invention has an imaging device configured with a contact image sensor, so even if the width of the conveying section in the direction perpendicular to the conveying direction is changed, the changed conveying section can be used simply by changing to a contact image sensor with a length corresponding to the size of the inspected product being conveyed, without adjusting the installation position of the contact image sensor or the imaging lens, etc. In this way, the inspection device of the present invention can accommodate multiple types of conveying sections with different widths in the direction perpendicular to the conveying direction without requiring adjustment of the installation position of the imaging device or the imaging lens, etc.
Furthermore, in the inspection device according to the present invention, the contact image sensor can be replaced with one of a length corresponding to the changed conveying width due to the replacement of the first conveying unit and the second conveying unit, and the replaced contact image sensor is attached by a bracket at a position where the distance from the inspected product remains unchanged before and after the replacement, so that the replaced contact image sensor can be used without adjusting the installation position or the imaging lens.

In the inspection device according to the present invention, it is preferable that the imaging device is disposed below, across the predetermined gap in the intersecting direction.

With this configuration, the inspection device of the present invention has the imaging device positioned below with a predetermined gap in the cross direction. Therefore, even if there is only limited space below the conveying section, it can accommodate changes in the width of the conveying section without any restrictions by simply using contact image sensors with different lengths in the direction perpendicular to the conveying direction.

In the inspection device according to the present invention, it is preferable that the imaging device is disposed above the device with the predetermined gap in the intersecting direction.

With this configuration, the inspection device of the present invention has the imaging device positioned above with a predetermined gap in the cross direction. Therefore, even if the conveying unit is changed to a wider one, the distance between the conveying unit and the contact image sensor can be maintained, preventing the inspection device from becoming larger in height.

This invention provides an inspection device that can accommodate multiple types of conveying sections with different widths in the direction perpendicular to the conveying direction, without the need to adjust the installation position of the imaging device or the imaging lens.

FIG. 1 is a schematic diagram of an inspection apparatus according to an embodiment of the present invention. FIG. 2 is a schematic side view of an inspection device according to an embodiment of the present invention. FIG. 3 is a view taken along the line AA in FIG. FIG. 4 is a schematic side view showing a modified example of the inspection device according to the embodiment of the present invention. FIG. 5 is a view taken along the line BB in FIG.

The following describes an inspection device according to one embodiment of the present invention, with reference to the drawings.

As shown in FIG. 1, the inspection device 1 of this embodiment is an inspection device that uses an imaging device to inspect a workpiece W as an inspection item. Examples of inspection items include products with flat bottoms, such as food, whose contents are tightly packed in a film-like packaging material, and food in trays.

In this embodiment, we will explain an example of inspecting a workpiece W, which is a product with a flat bottom whose contents are tightly packed in packaging material and to which a label WL (see Figure 2) is affixed.

The inspection device 1 of this embodiment uses an image of the workpiece W captured by an imaging device to inspect whether a label WL is attached to the bottom, whether the affixing position is correct, and whether there are any printing defects on the label WL. If the workpiece W is a type of product where information is printed directly on the packaging material rather than on a label, it can also inspect whether there are any printing defects on the packaging material, whether there are any printing defects on the expiration date, etc.

In addition, the inspection device 1 can also be used to inspect products with flat bottoms, such as food, whose contents are tightly packed in film-like packaging material, to see if the contents are caught in the sealed portion of the packaging material.

[Configuration of inspection device]
The inspection device 1 is disposed between a first transport unit 31 and a second transport unit 32, which are arranged at a predetermined gap G in the transport direction of the workpiece W (indicated by the arrow in FIG. 1 ). The first transport unit 31 is, for example, a belt conveyor, and transports the workpiece W to the second transport unit 32. The second transport unit 32 is, for example, a belt conveyor, and transports the workpiece W transported from the first transport unit 31 to a subsequent process. Here, an example of the subsequent process is an inspection process using an X-ray inspection device. The belt conveyor may also be a transparent conveyor. Note that, hereinafter, the first transport unit 31 and the second transport unit 32 may be collectively referred to simply as the "transport unit."

The inspection device 1 is configured to inspect the workpiece W as it passes through the gap G between the first conveying section 31 and the second conveying section 32.

The inspection device 1 is composed of an imaging device 10 and a processing unit 20.

The imaging device 10 is installed on one side (in this embodiment, the lower side in Figure 1) of the workpiece W, with a predetermined gap G sandwiched between them in a direction (in this embodiment, the vertical direction in Figure 1) that intersects the transport direction of the workpiece W. The imaging device 10 is held by a bracket 11 (see Figure 2), described below, at a position a predetermined distance away from the predetermined gap G.

The imaging device 10 is composed of a line sensor that uses a one-dimensional element in which pixels are arranged one-dimensionally on the light-receiving element surface as an imaging element, and images the workpiece W from one side to obtain a line-shaped image in the width direction perpendicular to the conveyance direction of the workpiece W. The imaging device 10 continuously images the workpiece W as it is being conveyed. The line-by-line images captured by the imaging device 10 are continuously input into the image acquisition unit to be constructed as a single image.

An operation unit 21 is connected to the processing unit 20. The operation unit 21 is composed of, for example, multiple keys and switches operated by the user, and soft keys on the display screen of the display unit 27 (described below). The operation unit 21 is operated, for example, to start or stop the operation of the inspection device 1, to set the type of work W and the number of inspections, to set various settings when changing the size of the imaging device 10, and to start the processing unit 20.

The processing unit 20 includes an image acquisition unit 22, a memory unit 23, an area identification unit 24, a determination unit 25, and a display control unit 26.

The image acquisition unit 22 is configured to include, for example, an image input board, acquires images line by line from the imaging device 10, and generates a single image from the acquired images line by line. The storage unit 23 stores the images generated by the image acquisition unit 22.

The area identification unit 24 performs image processing, such as binarization and edge detection, on the single image generated by the image acquisition unit 22 to identify the label area on the workpiece W. The label area is the area on the bottom of the workpiece W where a label WL is affixed. Note that if the workpiece W is a type that does not use a label, a print area on which characters, barcodes, etc. are printed may be identified instead of the label area.

When the inspection device 1 is used to inspect whether or not contents are caught in a sealed portion, the area identification unit 24 performs image processing, such as binarization and edge detection, on the single image generated by the image acquisition unit 22 to identify the sealed area on the workpiece W. The sealed area refers to, for example, the area from both ends of the packaging material to the inner edge of the sealed portion on a workpiece W in which the inner portion is sealed by a predetermined width from both opposing ends of the packaging material.

The determination unit 25 determines whether a label WL is attached to the bottom and whether its attachment position is correct, based on the single image generated by the image acquisition unit 22. Furthermore, the determination unit 25 uses a matching function, such as OCV (Optical Character Verification) or OCR (Optical Character Recognition), to determine whether there are any printing defects on the label WL for the single image generated by the image acquisition unit 22.

When the inspection device 1 is used to inspect whether or not contents are caught in sealed portions, the determination unit 25 determines whether or not contents are caught in the sealed portion of the packaging material in the sealed area identified by the area identification unit 24. The determination unit 25 can, for example, detect an abnormal portion from a single image generated by the image acquisition unit 22, and determine whether or not this detected abnormal portion is present in the sealed area, thereby determining whether or not contents are caught in the sealed portion of the packaging material.

The display control unit 26 controls the display on the display unit 27 connected to the processing unit 20. The display control unit 26 controls the display on the display unit 27 to display various information such as, for example, a single image generated by the image acquisition unit 22, the inspection results of the work W based on the judgment of the judgment unit 25, the total number of inspections, the number of good products, the total number of NG products, etc.

The display unit 27 is composed of a display device such as an LCD, and displays various information, including the inspection results of the workpiece W, under the control of the display control unit 26.

[Configuration of imaging device]
Next, a specific configuration of the imaging device 10 of this embodiment will be described with reference to FIGS.

The imaging device 10 of this embodiment is composed of a contact image sensor that integrates a light source, an imaging element, and an imaging lens. Advantages of using a contact image sensor as an imaging device include, for example, that compared to using a normal line camera that requires separate lighting and lenses, there is no distortion due to lenses or lighting, and shading correction or lighting adjustment is not required; the components required for imaging are compactly unitized, allowing for compact installation of the components required for imaging, thereby preventing the inspection device from becoming larger; no separate lighting is required, eliminating the need for lighting installation space or a separate lighting illumination area, allowing imaging to be performed using the small gaps that typically occur between conveying parts lined up in the conveying direction; and the size of the contact image sensor (the length in the direction perpendicular to the conveying direction) can be changed without changing the distance from the workpiece W.

In this embodiment, a contact image sensor is used as the imaging device 10, but it does not necessarily need to be placed in close contact with the workpiece W. The imaging device 10 is positioned so that the distance between the imaging device 10 and the workpiece W is, for example, approximately 50 mm.

As shown in Figures 2 and 3, the imaging device 10 is attached to the support base 33 of the first transport unit 31 via a bracket 11. A control box 12 containing the processing unit 20 is attached to the support base 33 of the first transport unit 31.

The bracket 11 has a support frame 11a that supports the imaging device 10 from below, and a pair of left and right connecting frames 11b. The support frame 11a is connected to the upper ends of the pair of left and right connecting frames 11b. The lower ends of the pair of left and right connecting frames 11b are connected to the support base 33.

The bracket 11 may also be composed of only a pair of left and right connecting frames 11b. In this case, both ends of the imaging device 10 in the direction perpendicular to the transport direction are directly supported by the pair of left and right connecting frames 11b.

[Regarding changes to imaging devices]
The transport section to which the inspection device 1 is applied includes a plurality of types of transport sections each having a different width in a direction perpendicular to the transport direction (hereinafter referred to as the "transport width") depending on the size of the workpiece W to be inspected.

When using an inspection device that uses a regular line camera, which requires separate lighting, as the imaging device, the following issues arise when trying to accommodate different conveying sections with different conveying widths. Note that the following issues apply when using the same line camera to accommodate changes in the conveying section.

Normally, when the workpiece W to be inspected is changed to a different type (different size), the conveying width (width perpendicular to the conveying direction) of the conveying section is also changed to a size appropriate for the new workpiece. The distance between the line camera and the workpiece must also be changed so that the entire workpiece with the changed width size can be properly imaged. For this reason, the bracket supporting the line camera must also be replaced, and the aforementioned distance must be adjusted accurately. The lighting position must also be adjusted. Furthermore, the lens must be adjusted as necessary.

When changing to a conveying section with a larger conveying width, it is necessary to increase the distance between the line camera and the workpiece in order to properly capture the entire large workpiece. If the line camera is installed below the conveying section, there is a limit to how far it can be separated from the workpiece in the limited space below the conveying section, which places restrictions on where the line camera can be installed. This limits the conveying width that can be accommodated.

In contrast, with the inspection device 1 of this embodiment, when handling conveying sections with different conveying widths, it is only necessary to replace the contact image sensor with a contact image sensor of a length corresponding to the conveying width. In this case, there is no need to change the distance between the contact image sensor and the workpiece W.

For this reason, when changing the contact image sensor in the inspection device 1 of this embodiment, it is only necessary to change the length of the support frame 11a in the direction perpendicular to the transport direction to match the length of the changed contact image sensor, and there is no need to change the connecting frame 11b to one of a different length.

In addition, if both ends of the imaging device 10 are directly supported by a pair of left and right connecting frames 11b, no modifications to the bracket 11 are necessary.

In this way, the inspection device 1 of this embodiment is applicable to the first conveying unit 31 and the second conveying unit 32, each of which is configured to be replaceable with units having different conveying widths, and is configured so that when the first conveying unit 31 and the second conveying unit 32 are replaced with units having different conveying widths, the imaging device 10 can be replaced with an imaging device having a length corresponding to the conveying width of the replaced conveying unit. The imaging device 10 is supported by the bracket 11 at a position where the distance from the workpiece W or the distance from the conveying surface of the conveying unit does not change before or after replacing the conveying unit.

[Action and effect]
As described above, in the inspection device according to this embodiment, the imaging device 10 is configured as a contact image sensor, so even if the conveying width of the conveying section is changed, the inspection device can be used without adjusting the installation position of the contact image sensor or the imaging lens, simply by changing the changed conveying section to a contact image sensor with a length corresponding to the size of the conveyed workpiece W. In this way, the inspection device according to this embodiment can accommodate a plurality of types of conveying sections with different conveying widths, without the need to adjust the installation position of the imaging device 10 or the imaging lens.

In addition, in the inspection device according to this embodiment, the imaging device 10 is positioned below with a predetermined gap G in the cross direction. Therefore, even if there is only limited space below the conveying section, it is possible to accommodate changes in the conveying width of the conveying section without any restrictions by simply using contact image sensors with different lengths in the direction perpendicular to the conveying direction.

In addition, the inspection device according to this embodiment allows the contact image sensor to be replaced with one of a length that corresponds to the changed conveying width due to replacement of the conveying unit, and the replaced contact image sensor is attached by bracket 11 at a position where the distance from the workpiece W remains the same before and after the replacement, so the replaced contact image sensor can be used without adjusting the installation position or imaging lens.

[Modification]
In this embodiment, an example in which the imaging device 10 is arranged below the conveying section has been described, but this is not limited to this. For example, the imaging device 10 may be arranged above with a predetermined gap G in the intersecting direction as shown in Figures 4 and 5.

The inspection device 101 relating to the modified example is suitable for inspecting products with flat top surfaces whose contents are tightly packed in packaging material. Figures 4 and 5 show the case where a product with a label WL affixed to its top surface is inspected as the workpiece W.

As shown in Figures 4 and 5, the inspection device 101 according to the modified example has a U-shaped frame 11c attached to the upper ends of a pair of left and right connecting frames 11b, and a support frame 11a connected to the upper left and right ends of the frame 11c. The imaging device 10 is attached to the underside of the support frame 11a. As a result, in the inspection device 101 according to the modified example, the imaging device 10 is positioned above the transport section.

In addition to the effects of this embodiment, the inspection device 101 according to the modified example has the following effects. That is, in the inspection device 101 according to the modified example, the imaging device 10 is positioned above with a predetermined gap G in the cross direction. Therefore, even if the conveying unit is changed to one with a larger conveying width, the distance between the conveying unit and the contact image sensor can be maintained, preventing the inspection device 101 from becoming larger in size in the height direction.

Note that the support methods for the imaging device 10 shown in this embodiment and the modified examples shown in Figures 4 and 5 are merely examples and are not intended to be limiting; other known support methods can also be used.

The inspection device according to this embodiment and the modified examples shown in Figures 4 and 5 can be used to inspect products with flat bottoms, such as food, whose contents are tightly packed in film-like packaging material to determine whether the contents are caught in the sealed portion of the packaging material. In this case, the device may be configured as follows:

For example, by placing a light on the side opposite the contact image sensor across a specified gap G and using an infrared imaging element as the imaging element for the contact image sensor, a transmitted image of the workpiece W can be obtained and the presence or absence of jamming can be inspected based on the transmitted image.

Although embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications may be made thereto without departing from the scope of the present invention. All such modifications and equivalents are intended to be encompassed by the following claims.

REFERENCE SIGNS LIST 1, 101 Inspection device 10 Imaging device 11 Bracket 11a Support frame 11b Connecting frame 11c Frame 12 Control box 20 Processing unit 21 Operation unit 22 Image acquisition unit 23 Memory unit 24 Area identification unit 25 Determination unit 26 Display control unit 27 Display unit 31 First conveying unit 32 Second conveying unit 33 Support table W Work (inspection item)
WL Label G Specified gap

Claims (3)

An inspection device (1) that inspects an inspection product (W) when the inspection product passes between a first conveying section (31) and a second conveying section (32) that are arranged with a predetermined gap (G) between them in a conveying direction of the inspection product,
an imaging device (10) that is provided on one side of the predetermined gap in a direction intersecting the conveying direction of the inspection product and that captures an image of the inspection product from the one side;
the imaging device is configured by a contact image sensor in which a light source, an imaging element, and an imaging lens are integrated ;
the first conveying unit and the second conveying unit are configured to be replaceable with units having different conveying widths, which are widths in a direction perpendicular to the conveying direction,
The inspection device is characterized in that the contact image sensor can be replaced with one having a length corresponding to the changed conveying width due to the replacement, and is attached by a bracket (11) at a position where the distance from the inspection product does not change before and after the replacement . The inspection device described in claim 1, characterized in that the imaging device is arranged below, across the specified gap in the intersecting direction. The inspection device described in claim 1, characterized in that the imaging device is positioned above, across the specified gap in the intersecting direction.