JP2021124461A - X-ray inspection device - Google Patents

Abstract

To provide an X-ray inspection device that can achieve improvement in inspection accuracy.SOLUTION: An X-ray inspection device 1 comprises: an X-ray irradiation unit 6 that irradiates an article G with an X-ray; an X-ray detection unit 7 that detects an X-ray; and a control unit 10 that inspects the article G on the basis of an image prepared from a detection result of the X-ray detected by the X-ray detection unit 7. The control unit 10 is configured to implement first processing of determining presence or absence of a foreign matter in the article G by use of luminance of each pixel of the image and a first threshold pertaining to a foreign matter inspection of the article G, and second processing of determining whether the quality of the article G is good or not by use of the luminance of each pixel of the image and a second threshold lower than the first threshold pertaining to the quality inspection of the article G, in which the second processing is configured to, when a range of the pixel in which the luminance is less than the first threshold and equal to or more than the second threshold is equal to or more than a prescribed range, determine that the article G is defective.SELECTED DRAWING: Figure 1

Description

The present invention relates to an X-ray inspection apparatus.

As a conventional X-ray inspection apparatus, for example, the apparatus described in Patent Document 1 is known. The X-ray inspection apparatus described in Patent Document 1 includes an X-ray irradiation unit that irradiates an article with X-rays and an X-ray detection unit that detects X-rays, and is created based on the X-ray detection result. The X-ray image is subjected to image processing to inspect the article.

International Publication No. 2006/001107

The X-ray inspection device inspects the article for the presence or absence of foreign matter, and determines whether the article is non-defective or defective. Goods are also defective if their quality is poor. For example, if a part of the article is harder than usual or is too soft, or if it has a part having different physical properties from the other part, the quality is poor and the product is defective. Conventionally, in the inspection of such defective products, the hardness of the articles is inspected by the operator directly contacting the articles. Manual work by an operator can vary depending on the experience and sensation of the operator.

One aspect of the present invention is to provide an X-ray inspection apparatus capable of improving inspection accuracy.

The X-ray inspection apparatus according to one aspect of the present invention includes an X-ray irradiation unit that irradiates an article with X-rays, an X-ray detection unit that detects X-rays, and an X-ray detection result detected by the X-ray detection unit. A foreign object in the article is provided with an inspection unit that inspects the article based on the image created from The second process of determining the quality of the article by using the first process of determining the presence or absence of the image, the brightness of each pixel of the image, and the second threshold value lower than the first threshold value related to the quality inspection of the article. And, in the second process, when the brightness is less than the first threshold value and the range of the pixels having the second threshold value or more is the predetermined range or more, it is determined that the article is a defective product.

The inventors of the present application have obtained the finding that when a poor quality part is present in an article, a feature different from that of a foreign substance appears in the X-ray detection result. The poor quality portion of the article does not appear as prominently in the detection result as the foreign matter, but has a certain range (region). Based on such findings, the inventors of the present application have found a relationship between the threshold value and the range of the brightness of each pixel of the image. Therefore, in the X-ray inspection apparatus according to one aspect of the present invention, in the second processing, when the brightness is less than the first threshold value and the range of pixels having the second threshold value or more is the predetermined range or more, the article is defective. Is determined to be. As a result, the X-ray inspection apparatus can perform not only foreign matter inspection but also quality inspection of articles. Therefore, in the X-ray inspection apparatus, the inspection accuracy can be improved.

In one embodiment, the X-ray detector includes a first detector that detects X-rays in the first energy band that has passed through the article, and an X-ray in a second energy band that is different from the first energy band that has passed through the article. The inspection unit may inspect the article based on the image created from the detection results of the first detection unit and the second detection unit. In an article, the absorption of X-rays in the two energy bands differs depending on the physical characteristics. Therefore, in the X-ray inspection apparatus, by using an image created from the detection results of two different energy bands, it becomes possible to more prominently catch a foreign substance or a quality defect. As a result, the X-ray inspection apparatus can further improve the inspection accuracy.

In one embodiment, the inspection unit performs binarization processing of the image based on the brightness that is less than the first threshold value and is greater than or equal to the second threshold value, acquires the area of the region in the binarized image, and obtains the area. If the area of is equal to or larger than a predetermined area, it may be determined that the article is defective. With this configuration, it is possible to more accurately determine the quality of the article.

According to one aspect of the present invention, the inspection accuracy can be improved.

FIG. 1 is a configuration diagram of an X-ray inspection apparatus according to an embodiment. FIG. 2 is a configuration diagram of the inside of the shield box shown in FIG. 3 (a) and 3 (b) are diagrams showing a transparent image. FIG. 4 is a diagram for explaining a foreign matter inspection according to the first process. FIG. 5 is a diagram for explaining a quality inspection related to the second process.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicate description will be omitted.

As shown in FIG. 1, the X-ray inspection apparatus 1 displays an apparatus main body 2, a support leg 3, a shield box 4, a transport unit 5, an X-ray irradiation unit 6, and an X-ray detection unit 7. It includes an operation unit 8 and a control unit (inspection unit) 10. The X-ray inspection device 1 generates an X-ray transmission image of the article G while transporting the article G, and inspects the article G based on the X-ray transmission image (for example, storage number inspection, foreign matter inspection, shortage inspection, Perform crack / chip inspection, etc.). The article G before inspection is carried into the X-ray inspection device 1 by the carry-in conveyor 51. The article G after the inspection is carried out from the X-ray inspection device 1 by the carry-out conveyor 52. The article G determined to be defective by the X-ray inspection device 1 is sorted out of the production line by a sorting device (not shown) arranged downstream of the carry-out conveyor 52. The article G determined to be a non-defective product by the X-ray inspection device 1 passes through the sorting device as it is. In this embodiment, article G is meat.

The device main body 2 houses the control unit 10 and the like. The support legs 3 support the device main body 2. The shield box 4 is provided in the device main body 2. The shield box 4 prevents the leakage of X-rays (electromagnetic waves) to the outside. Inside the shield box 4, an inspection area R for inspecting the article G by X-ray is provided. The shield box 4 is formed with a carry-in inlet 4a and a carry-out outlet 4b. The article G before inspection is carried into the inspection area R from the carry-in conveyor 51 via the carry-in inlet 4a. The article G after the inspection is carried out from the inspection area R to the carry-out conveyor 52 via the carry-out port 4b. Each of the carry-in inlet 4a and the carry-out outlet 4b is provided with an X-ray shielding curtain (not shown) for preventing X-ray leakage.

The transport portion 5 is arranged so as to penetrate the center of the shield box 4. The transport unit 5 transports the article G along the transport direction A from the carry-in port 4a to the carry-out port 4b via the inspection area R. The transport unit 5 is, for example, a belt conveyor hung between the carry-in inlet 4a and the carry-out outlet 4b. The transport unit 5 which is a belt conveyor may protrude outward from the carry-in inlet 4a and the carry-out outlet 4b.

As shown in FIGS. 1 and 2, the X-ray irradiation unit 6 is arranged in the shield box 4. The X-ray irradiation unit 6 irradiates the article G transported by the transport unit 5 with X-rays. The X-ray irradiation unit 6 has, for example, an X-ray tube that emits X-rays and a narrowing unit that spreads the X-rays emitted from the X-ray tube in a fan shape in a plane perpendicular to the transport direction A. .. The X-rays emitted from the X-ray irradiation unit 6 include X-rays in various energy bands from low energy (long wavelength) to high energy (short wavelength). The "low" and "high" in the low energy band and the high energy band described above indicate that they are relatively "low" and "high" among the plurality of energy bands irradiated from the X-ray irradiation unit 6. It does not indicate a specific range.

The X-ray detection unit 7 is arranged in the shield box 4. The X-ray detection unit 7 detects each X-ray in a plurality of energy bands that have passed through the article G. In the present embodiment, the X-ray detection unit 7 is configured to detect X-rays in the low energy band (first energy band) and X-rays in the high energy band (second energy band). That is, the X-ray detection unit 7 has a first line sensor (first detection unit) 11 and a second line sensor (second detection unit) 12. The first line sensor 11 and the second line sensor 12 are each composed of X-ray detection elements arranged one-dimensionally along a horizontal direction perpendicular to the transport direction A. The first line sensor 11 detects low-energy band X-rays that have passed through the article G and the transport belt of the transport unit 5. The second line sensor 12 detects high-energy band X-rays that have passed through the article G, the transport belt of the transport unit 5, and the first line sensor 11.

As shown in FIG. 1, the display operation unit 8 is provided on the device main body 2. The display operation unit 8 displays various information and accepts input of various conditions. The display operation unit 8 is, for example, a liquid crystal display and displays an operation screen as a touch panel. In this case, the operator can input various conditions via the display operation unit 8.

The control unit 10 is arranged in the device main body 2. The control unit 10 is located downstream of each unit of the X-ray inspection device 1 (in this embodiment, the transport unit 5, the X-ray irradiation unit 6, the X-ray detection unit 7, the display operation unit 8, and the X-ray inspection device 1). Controls the operation of the arranged sorting device (not shown). The sorting device is a device that removes an inspected object (article) determined to be a defective product by an image inspection by the X-ray inspection device 1 from the transport path. The control unit 10 includes a processor such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and a storage such as an SSD (Solid State Drive). A program for controlling the X-ray inspection apparatus 1 is recorded in the ROM. The low energy band X-ray detection result is input to the control unit 10 from the first line sensor 11 of the X-ray detection unit 7, and the high energy band X from the second line sensor 12 of the X-ray detection unit 7. The line detection result is input.

The control unit 10 generates a transparent image based on the detection results of the first line sensor 11 and the second line sensor 12. The control unit 10 generates a soft image (first transmitted image) P10 based on the detection result of X-rays in the low energy band of the first line sensor 11. FIG. 3A is an example of the soft image P10 generated by the processing of the control unit 10. The soft image P10 has a relatively high contrast and is dark as a whole. The control unit 10 generates a hard image (second transmission image) P20 based on the detection result of X-rays in the high energy band of the second line sensor 12. FIG. 3B is an example of the hard image P20 generated by the processing of the control unit 10. The hard image P20 has a relatively low contrast and is bright as a whole.

The control unit 10 uses an image processing algorithm to perform processing (image processing) on the soft image P10 and the hard image P20 to generate a processed image. The image processing algorithm is a type indicating a processing procedure of image processing applied to the soft image P10 and the hard image P20. The image processing algorithm is composed of one image processing filter or a combination of a plurality of image processing filters. A plurality of image processing algorithms can be acquired from the outside via a network such as the Internet. Further, the plurality of image processing algorithms can be acquired from an external storage medium such as a USB memory or a removable hard disk. At least one or more of the plurality of image processing algorithms adopts genetic algorithms (GA = Genetic Algorithms), which are methods that apply the mechanisms of heredity and evolution in the biological world, and the specifications of the X-ray inspection apparatus 1 or It can be automatically generated from a plurality of image processing filters based on inspection conditions and the like. At least a part of the plurality of image processing algorithms can be appropriately set by the operator via the display operation unit 8.

By carrying out the first process, the control unit 10 determines whether or not the article G contains a foreign matter F (see FIG. 4). The control unit 10 determines the presence or absence of the foreign matter F in the article G by using the brightness of each pixel of the image and the first threshold value T1 (see FIG. 4) related to the foreign matter inspection of the article G.

Specifically, the control unit 10 performs a process of matching the size, brightness, position, etc. of the soft image P10 and the hard image P20, and the brightness value of the soft image P10 and the brightness value of the hard image P20 that have undergone the process. Is divided by each pixel to perform a process of extracting the difference between the soft image P10 and the hard image P20. The control unit 10 generates a processed image in which noise is removed from the image from which the difference is extracted, binarizes the processed image with a certain value as a threshold value, and generates a binarized image (binarization). The control unit 10 superimposes the binarized image and the hard image P20 to generate a determination image P30 (see FIG. 4).

The control unit 10 determines whether or not the article G contains the foreign matter F based on the determination image P30. As shown in FIG. 4, when the brightness value exceeds the first threshold value T1 in the determination image P30, the control unit 10 determines that the article G contains the foreign matter F. In the present embodiment, the control unit 10 determines in the first process that the article G contains one foreign matter F. The control unit 10 stores the first determination result of the first process in the storage unit. The first threshold value T1 is appropriately set by a test or the like according to the properties of the article G. Specifically, the first threshold value T1 can be set by using a sample in which a foreign substance is mixed.

The control unit 10 determines the quality of the article G by carrying out the second process. In the present embodiment, the control unit 10 determines that the article G is a defective product when the article G includes a portion W (see FIG. 5) that is harder than the other portions. The control unit 10 determines the quality of the article G by using the brightness of each pixel of the image and the second threshold value T2 lower than the first threshold value T1 related to the quality inspection of the article G. In the second process, the control unit 10 determines that the article G is a defective product when the range of pixels whose brightness is less than the first threshold value T1 and is equal to or higher than the second threshold value T2 is equal to or greater than a predetermined range.

Specifically, the control unit 10 determines the quality of the article G based on the determination image P30. As shown in FIG. 5, in the determination image P30, when the brightness is less than the first threshold value T1 and the range of pixels having the second threshold value T2 or more is equal to or more than a predetermined range, the article G is defective. Judged as a non-defective product. Specifically, the control unit 10 performs binarization processing of the image based on the brightness that is less than the first threshold value T1 and is equal to or higher than the second threshold value T2, acquires the area of the region in the binarized image, and obtains the area. When the area of the region is equal to or larger than the predetermined area, it is determined that the article G is a defective product. The control unit 10 acquires the area of the region in the determination image P30 by image processing. The control unit 10 stores the second determination result of the second process in the storage unit. The second threshold value T2 and the predetermined area are appropriately set by a test or the like according to the properties of the article G. Specifically, the second threshold value T2 and the predetermined area can be set by using a sample having a hard portion W.

The control unit 10 executes the first process and the second process in parallel. When the control unit 10 determines that the article G contains a foreign substance F in the first process and / or determines that the article G is a defective product in the second process, the control unit 10 sends a distribution signal to the sorting device. Is output. As a result, the sorting device sorts the article G out of the production line. Further, when the control unit 10 determines that the article G has a foreign matter F in the first process and / or determines that the article G is a defective product in the second process, the control unit 10 informs the display operation unit 8. Display that fact. Specifically, when the control unit 10 determines that the article G contains a foreign substance F, the control unit 10 causes the display operation unit 8 to display information for notifying the inclusion of the foreign substance, and determines that the article G is a defective product. Is to display the information for notifying the defective product on the display operation unit 8.

Subsequently, the operation of the X-ray inspection device 1 will be described. The article G to be inspected is carried from the carry-in conveyor 51 into the inspection area R of the X-ray inspection device 1 via the carry-in inlet 4a (see FIG. 1). In the X-ray inspection apparatus 1, the X-ray irradiation unit 6 irradiates the article G with X-rays, and the X-ray detection unit 7 detects each X-ray in a plurality of energy bands transmitted through the article G. In the present embodiment, the first line sensor 11 of the X-ray detection unit 7 detects low-energy band X-rays, and the second-line sensor 12 of the X-ray detection unit 7 detects high-energy band X-rays ( (See Fig. 2).

The control unit 10 generates a soft image P10 based on the detection result of the low energy band X-ray by the first line sensor 11, and based on the detection result of the high energy band X-ray by the second line sensor 12. A hard image P20 is generated. Subsequently, the control unit 10 generates a determination image P30 from the generated soft image P10 and hard image P20.

The control unit 10 performs the first process based on the determination image P30. That is, the control unit 10 inspects the presence or absence of the foreign matter F. Further, the control unit 10 performs the second process based on the determination image P30. That is, the control unit 10 inspects for defective products. When the control unit 10 makes an NG determination (foreign matter contamination determination, defective product determination) in at least one of the first process and the second process, the control unit 10 outputs a distribution signal to the distribution device. Further, the control unit 10 causes the display operation unit 8 to display the determination result of the NG determination.

The operation and effect of the X-ray inspection apparatus 1 described above will be described. The inventors of the present application have obtained the finding that when a poor quality portion is present in the article G, a feature different from that of the foreign substance F appears in the X-ray detection result. The portion W of the article G, which is harder than the other portions, does not appear as significantly in the detection result as the foreign matter F, but has a certain range (area). Based on such findings, the inventors of the present application have found a relationship between the luminance threshold and the range. Therefore, in the X-ray inspection apparatus 1 according to the present embodiment, when the brightness is less than the first threshold value T1 and the range of pixels having the second threshold value T2 or more is equal to or more than a predetermined range, the article G is set in the control unit 10. Judge as a defective product. As a result, the X-ray inspection apparatus 1 can perform not only the foreign matter inspection but also the quality inspection of the article G. Therefore, the X-ray inspection apparatus 1 can improve the inspection accuracy.

In the X-ray inspection apparatus 1 according to the present embodiment, the X-ray detection unit 7 has a first line sensor 11 that detects X-rays in the first energy band that has passed through the article G, and a first energy band that has passed through the article G. It has a second line sensor 12 that detects X-rays in a second energy band different from the above. The control unit 10 inspects the article G based on the images created from the detection results of the first line sensor 11 and the second line sensor 12. In the article G, the absorption of X-rays in the two energy bands differs depending on the physical characteristics. Therefore, in the X-ray inspection apparatus 1, by using the soft image P10 and the hard image P20 created from the detection results of the two different energy bands, it becomes possible to more prominently catch the foreign matter or the quality defect. As a result, the X-ray inspection apparatus 1 can further improve the inspection accuracy.

In the X-ray inspection apparatus 1 according to the present embodiment, the control unit 10 binarizes the image based on the soft image P10 and the hard image P20 based on the brightness which is less than the first threshold value T1 and equal to or more than the second threshold value T2. The process is performed to obtain the area of the region in the binarized image, and when the area of the region is equal to or larger than the predetermined area, it is determined that the article G is a defective product. With this configuration, it is possible to more accurately determine the quality of the article G.

Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

In the above embodiment, the embodiment in which the X-ray detection unit 7 has the first line sensor 11 and the second line sensor 12 has been described as an example. However, the X-ray detector may have at least one line sensor. In this case, the control unit 10 determines the foreign matter F using two different image processing algorithms based on one transparent image.

In the above embodiment, the control unit 10 has described as an example a mode in which the article G determines that the article G is a defective product when the article G contains a hard portion W (see FIG. 5) in the second process. However, in the second process, the control unit 10 may determine the quality of the article G based on other factors. For example, the control unit 10 includes a portion that is too soft in the article G, a sparse content in the article G, or a large amount of fat in the article G (meat) (the balance between lean and fat is balanced). If it is bad), it may be determined that the quality of the article G is poor.

In the above embodiment, the embodiment in which the X-ray inspection device 1 includes the transport unit 5 has been described as an example. However, the X-ray inspection apparatus does not have to be provided with a transport unit.

1 ... X-ray inspection device, 6 ... X-ray irradiation unit, 7 ... X-ray detection unit, 11 ... 1st line sensor (1st detection unit), 12 ... 2nd line sensor (2nd detection unit), F ... Foreign matter , G ... article, T1 ... first threshold, T2 ... second threshold.

Claims (3)

An X-ray irradiation unit that irradiates an article with X-rays,
An X-ray detector that detects the X-rays and
An inspection unit that inspects the article based on an image created from the X-ray detection result detected by the X-ray detection unit is provided.
The inspection unit
A first process for determining the presence or absence of a foreign substance in the article by using the brightness of each pixel of the image and the first threshold value related to the foreign substance inspection of the article.
Using the brightness of each pixel of the image and the second threshold value lower than the first threshold value related to the quality inspection of the article, a second process of determining the quality of the article is performed.
In the second process, when the brightness is less than the first threshold value and the range of the pixels having the second threshold value or more is equal to or more than a predetermined range, the article is determined to be defective, an X-ray inspection. Device. The X-ray detector
A first detection unit that detects the X-rays in the first energy band that has passed through the article, and
It has a second detection unit that detects the X-rays in a second energy band different from the first energy band that has passed through the article.
The X-ray inspection apparatus according to claim 1, wherein the inspection unit inspects the article based on the image created from the detection results of the first detection unit and the second detection unit. The inspection unit performs binarization processing of the image based on the brightness that is less than the first threshold value and is equal to or higher than the second threshold value, acquires the area of the region in the binarized image, and obtains the area of the region. The X-ray inspection apparatus according to claim 1 or 2, wherein when the area is equal to or larger than a predetermined area, it is determined that the article is a defective product.

Images