JP6979672B2 - X-ray inspection equipment - Google Patents

Description

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

An X-ray irradiation unit that irradiates an article with X-rays, a low-energy band X-ray that has passed through the article, an X-ray detection unit that detects high-energy band X-rays that have passed through the article, and a low-energy band X-ray. There is known an X-ray inspection apparatus including a processing unit for determining whether or not an article contains a foreign substance based on the detection result of X-rays in the high energy band and the detection result of X-rays in a high energy band (for example, a patent). See Document 1). According to such an X-ray inspection device, for example, an X-ray transmission image acquired as a detection result of X-rays in a low energy band and an X-ray transmission image acquired as a detection result of X-rays in a high energy band. By taking the difference between the above, even a foreign substance having a small difference in X-ray attenuation characteristics from the article can be detected with high accuracy.

Japanese Unexamined Patent Publication No. 2015-155830

In the X-ray inspection apparatus as described above, an article containing a first portion having a first physical property and a second portion having a second physical property is targeted for inspection, and a foreign substance having a small difference in X-ray attenuation characteristics from the article. May be detected. For example, it is a case where beef containing lean meat and fat meat is targeted for inspection and bone fragments are detected as foreign substances.

An object of the present invention is to provide an X-ray inspection apparatus capable of accurately detecting a foreign substance in an article containing a first portion having a first physical characteristic and a second portion having a second physical characteristic.

The X-ray inspection apparatus of the present invention has an X-ray irradiation unit that irradiates an article including a first portion having a first physical property and a second portion having a second physical property, and a first energy band transmitted through the article. X-rays and the X-ray detector that detects the X-rays in the second energy band that have passed through the article, the first detection result of the X-rays in the first energy band, and the second detection of the X-rays in the second energy band. A processing unit for determining whether or not the article contains foreign matter based on the result is provided, and the processing unit performs the first processing using the first detection result and the second detection result acquired for the article. By carrying out, it is determined whether or not foreign matter is contained in the first part, and by carrying out the second treatment using the first detection result and the second detection result acquired for the article, the second part The first process is a process of combining the first detection result and the second detection result acquired in advance for the first portion, and the second process is a second process in advance. This is a process of combining the first detection result and the second detection result acquired for the portion.

In this X-ray inspection apparatus, in order to determine whether or not a foreign substance is contained in the first portion, a first process of combining the first detection result and the second detection result acquired in advance for the first portion is performed. Will be done. Further, in order to determine whether or not the second portion contains a foreign substance, a second process is performed in which the first detection result and the second detection result acquired in advance for the second portion are combined. By these, for example, in order to determine whether or not the first portion contains a foreign substance and whether or not the second portion contains a foreign substance, the first detection result and the second detection result are combined in the same manner. Foreign matter can be detected more accurately than in the case where the above-mentioned processing is carried out. Therefore, according to this X-ray inspection apparatus, foreign matter can be accurately detected in an article including a first portion having a first physical characteristic and a second portion having a second physical characteristic.

In the X-ray inspection apparatus of the present invention, the first process is a process of adjusting the luminance values between the corresponding pixels in the first detection result and the second detection result acquired in advance for the first portion for each luminance value. The second process may be a process of adjusting the luminance values between the corresponding pixels in the first detection result and the second detection result acquired in advance for the second portion for each luminance value. According to this, it is possible to suitably determine whether or not the first portion contains a foreign substance and whether or not the second portion contains a foreign substance.

In the X-ray inspection apparatus of the present invention, the processing unit performs the first processing on the region corresponding to the entire article by using the first detection result and the second detection result acquired for the article. By determining whether or not the portion contains a foreign substance, and using the first detection result and the second detection result acquired for the article, the second treatment is performed on the region corresponding to the entire article. It may be determined whether or not foreign matter is contained in the two portions. According to this, it is possible to easily and accurately determine whether or not the first portion contains a foreign substance and whether or not the second portion contains a foreign substance.

In the X-ray inspection apparatus of the present invention, the processing unit has a first region and a second region corresponding to the first part in the article based on at least one of the first detection result and the second detection result acquired for the article. By extracting the second region corresponding to the portion and performing the first treatment on the first region using the first detection result and the second detection result obtained for the article, the first portion contains a foreign substance. By performing the second treatment on the second region using the first detection result and the second detection result acquired for the article, it is determined whether or not the second portion contains a foreign substance. May be determined. According to this, it is possible to more accurately determine whether or not the first portion contains a foreign substance and whether or not the second portion contains a foreign substance.

According to the present invention, it is possible to provide an X-ray inspection apparatus capable of accurately detecting a foreign substance in an article containing a first portion having a first physical characteristic and a second portion having a second physical characteristic. ..

It is a block diagram of the X-ray inspection apparatus of one Embodiment. It is a block diagram of the inside of the shield box shown in FIG. (A) is a histogram of the luminance value for the first part of the article, and (b) is a graph showing the relationship between the luminance value used for the first processing and the multiplier. (A) is a histogram of the luminance value for the second part of the article, and (b) is a graph showing the relationship between the luminance value used in the second processing and the multiplier. It is a figure which shows the relationship between the article, the difference of the luminance value acquired by the execution of the 1st process, and the difference of the luminance value acquired by the execution of the 2nd process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts 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 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 quantity inspection, foreign matter contamination inspection, missing item inspection). , 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 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 good product by the X-ray inspection device 1 passes through the sorting device as it is.

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 apparatus main body 2. The shield box 4 prevents X-rays from leaking 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 port 4b. The article G before inspection is carried from the carry-in conveyor 51 into the inspection area R 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 unit 5 is arranged in the shield box 4. The transport unit 5 transports the article G from the carry-in inlet 4a to the carry-out port 4b via the inspection area R along the transport direction A. The transport unit 5 is, for example, a belt conveyor spanned between the carry-in inlet 4a and the carry-out port 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 collimator 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-ray detection unit 7 is arranged in the shield box 4. The X-ray detection unit 7 has a first line sensor 11 and a second line sensor 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 X-rays in the low energy band (first energy band) that have passed through the article G and the transport belt of the transport unit 5. The second line sensor 12 detects X-rays in the high energy band (second energy band) transmitted 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 in the apparatus 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 controls the operation of each unit of the X-ray inspection device 1. The control unit 10 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The low energy band X-ray detection result (first detection result) is input to the control unit 10 from the first line sensor 11 (see FIG. 2) of the X-ray detection unit 7, and the X-ray detection unit 7 The detection result (second detection result) of the X-ray in the high energy band is input from the second line sensor 12 (see FIG. 2). The control unit 10 functions as a processing unit for determining whether or not the article G contains a foreign substance based on the detection result of the X-ray in the low energy band and the detection result of the X-ray in the high energy band.

An example of the foreign matter detection process performed in the X-ray inspection apparatus 1 configured as described above will be described. In the following example, as shown in FIG. 5A, an article G (eg, fat) comprising a first portion P1 having the first physical characteristics (eg, lean meat) and a second portion P2 having the second physical characteristics (eg, fat). This is an example of detecting a foreign substance F (for example, a bone fragment) using beef as an inspection target. The first and second physical properties mean physical properties in which the attenuation characteristics (energy characteristics) of X-rays are different from each other.

First, an article G containing only the first portion P1 is prepared, and the article G is hung on the X-ray inspection device 1. As a result, as shown in FIG. 3A, the detection result of X-rays in the low energy band (broken line) and the detection result of X-rays in the high energy band (solid line) for the article G containing only the first portion P1. ) Is acquired. FIG. 3A is a histogram of the luminance value in the X-ray transmission image of the article G containing only the first portion P1, and the frequency on the vertical axis corresponds to the number of pixels in the X-ray transmission image of the article G. ..

Subsequently, the control unit 10 calculates a multiplier for matching the luminance value LH of the X-rays in the high energy band with the luminance value LL of the X-rays in the low energy band at the same frequency F. By performing the calculation of the multiplier for all frequencies, the control unit 10 acquires the relationship between the luminance value of the X-ray in the high energy band and the multiplier, as shown in FIG. 3B, and obtains the multiplier. Remember the relationship.

As a result, the control unit 10 corrects the brightness value by multiplying the detection result of the high energy band X-rays acquired for the first portion P1 by a multiplier for each brightness value, and corrects the corrected high energy band X-rays. It is possible to carry out the first process of taking the difference between the detection result and the detection result of the X-ray in the low energy band acquired for the first portion P1 for each pixel. That is, in the first process, the luminance values between the corresponding pixels in the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired in advance for the first portion P1 are adjusted for each luminance value. It can be said to be processing. Further, it can be said that the first process is a process of combining the detection result of the high energy band X-ray and the detection result of the low energy band X-ray acquired in advance for the first portion P1.

While preparing for the implementation of the above first treatment, an article G containing only the second portion P2 is prepared, and the article G is hung on the X-ray inspection apparatus 1. As a result, as shown in FIG. 4A, the detection result of X-rays in the low energy band (broken line) and the detection result of X-rays in the high energy band (solid line) for the article G containing only the second portion P2. ) Is acquired. FIG. 4A is a histogram of the luminance value in the X-ray transmission image of the article G containing only the second portion P2, and the frequency on the vertical axis corresponds to the number of pixels in the X-ray transmission image of the article G. ..

Subsequently, the control unit 10 calculates a multiplier for matching the luminance value LH of the X-rays in the high energy band with the luminance value LL of the X-rays in the low energy band at the same frequency F. By performing the calculation of the multiplier for all frequencies, the control unit 10 acquires the relationship between the luminance value of the X-ray in the high energy band and the multiplier, as shown in FIG. 4B, and obtains the multiplier. Remember the relationship.

As a result, the control unit 10 corrects the brightness value by multiplying the detection result of the high energy band X-rays acquired for the second portion P2 by a multiplier for each brightness value, and corrects the corrected high energy band X-rays. It is possible to carry out the second process of taking the difference between the detection result and the detection result of the X-ray in the low energy band acquired for the second portion P2 for each pixel. That is, in the second process, the luminance values between the corresponding pixels in the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired in advance for the second portion P2 are adjusted for each luminance value. It can be said to be processing. Further, it can be said that the second process is a process of combining the detection result of the high energy band X-ray and the detection result of the low energy band X-ray acquired in advance for the second portion P2.

After preparing for the implementation of the first treatment and the preparation for the implementation of the second treatment, as shown in FIG. 5, the first portion P1 having the first physical characteristics and the second portion P2 having the second physical characteristics are provided. The inspection of the containing article G is started.

First, the control unit 10 uses the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired for the article G including the first portion P1 and the second portion P2 to obtain the article G. By performing the first processing on the region corresponding to the whole, the difference in the brightness value is acquired as shown in FIG. 5 (b). Subsequently, the control unit 10 compares the difference in the luminance value with the preset first threshold value T1, and determines that the region exceeding the first threshold value T1 is the region corresponding to the foreign matter F. As described above, the control unit 10 uses the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired for the article G including the first portion P1 and the second portion P2 to form the article. By performing the first treatment on the region corresponding to the entire region of G, it is determined whether or not the first portion P1 contains the foreign matter F.

On the other hand, the control unit 10 has a high-energy band X-ray detection result and a low-energy band X-ray detection result (as described above) acquired for the article G including the first portion P1 and the second portion P2. By performing the second processing on the region corresponding to the entire article G using the same detection result), the difference in the brightness value is acquired as shown in FIG. 5 (c). Subsequently, the control unit 10 compares the difference in the luminance value with the preset second threshold value T2, and determines that the region exceeding the second threshold value T2 is the region corresponding to the foreign matter F. As described above, the control unit 10 uses the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired for the article G including the first portion P1 and the second portion P2 to form the article. By performing the second treatment on the region corresponding to the entire region of G, it is determined whether or not the second portion P2 contains the foreign matter F.

(B) and (c) of FIG. 5 show the difference in the luminance values of the pixels located on the one-point chain line shown in (a) of FIG. In FIG. 5B, the noise is smaller in the region corresponding to the first portion P1 than in the region corresponding to the second portion P2, and in the region corresponding to the foreign matter F contained in the first portion P1, the region corresponds to the foreign matter F. The difference between the luminance values exceeds the first threshold value T1 (that is, the foreign matter F contained in the first portion P1 is detected). This is because the difference in the luminance values shown in FIG. 5B is combined with the high-energy band X-ray detection result and the low-energy band X-ray detection result previously acquired for the first portion P1. This is because it is the result of performing one process.

On the other hand, in FIG. 5C, the noise is smaller in the region corresponding to the second portion P2 than in the region corresponding to the first portion P1, which corresponds to the foreign matter F contained in the second portion P2. In the region where the noise is generated, the difference between the luminance values exceeds the second threshold value T2 (that is, the foreign matter F contained in the second portion P2 is detected). This is because the difference in the luminance values shown in FIG. 5 (c) combines the high-energy band X-ray detection results and the low-energy band X-ray detection results previously acquired for the second portion P2. This is because it is the result of performing two treatments.

As described above, the X-ray inspection apparatus 1 detects high-energy band X-rays previously acquired for the first portion P1 in order to determine whether or not the first portion P1 contains a foreign substance F. The first process of combining the result and the detection result of the X-ray in the low energy band is carried out. Further, in order to determine whether or not the second portion P2 contains a foreign substance F, the detection result of the high energy band X-ray and the detection result of the low energy band X-ray acquired in advance for the second portion P2. The second process is carried out. Based on these, for example, in order to determine whether or not the first portion P1 contains the foreign matter F and whether or not the second portion P2 contains the foreign matter F, the detection result of X-rays in the high energy band And, compared to the case where the same process of combining the detection results of X-rays in the low energy band is performed, the foreign matter F is contained in the first portion P1 or the second portion P2, regardless of whether the foreign matter F is contained in the foreign matter P2. F can be detected with high accuracy. Therefore, according to the X-ray inspection apparatus 1, the foreign matter F can be accurately detected in the article G including the first portion P1 having the first physical characteristics and the second portion P2 having the second physical characteristics.

As an example, in the first process, the luminance values between the corresponding pixels in the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired in advance for the first portion P1 are adjusted for each luminance value. It is a process to incorporate. Further, in the second process, the luminance values between the corresponding pixels in the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired in advance for the second portion P2 are adjusted for each luminance value. It is a process. Thereby, it is possible to suitably determine whether or not the first portion P1 contains the foreign matter F and whether or not the second portion P2 contains the foreign matter F.

The control unit 10 uses the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired for the article G to perform the first process for the region corresponding to the entire article G. Therefore, it is determined whether or not the first portion P1 contains the foreign matter F. Further, the control unit 10 performs the second processing on the region corresponding to the entire article G by using the detection result of the high energy band X-ray and the detection result of the low energy band X-ray acquired for the article G. By doing so, it is determined whether or not the second portion P2 contains the foreign matter F. Thereby, it is possible to easily and accurately determine whether or not the first portion P1 contains the foreign matter F and whether or not the second portion P2 contains the foreign matter F.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, the control unit 10 uses the high-energy band X-ray detection result and the low-energy band X-ray detection result acquired for the article G to perform the first processing for the first region corresponding to the first portion P1. By carrying out, it is determined whether or not the first portion P1 contains a foreign substance F, and the detection result of the high energy band X-ray and the low energy band X-ray detection result acquired for the article G are obtained. It may be used to determine whether or not the second portion P2 contains a foreign substance F by performing the second treatment on the second region corresponding to the second portion P2. In this case, the control unit 10 corresponds to the first portion P1 in the article G based on at least one of the high energy band X-ray detection result and the low energy band X-ray detection result acquired for the article G. The second region corresponding to the first region and the second portion P2 to be used is extracted in advance. According to this, it is possible to more accurately determine whether or not the first portion P1 contains the foreign matter F and whether or not the second portion P2 contains the foreign matter F.

Regarding the article G, for example, when two kinds of foods are contained in one package while being separated from each other, one kind of food is regarded as the first portion P1 and the other kind of foods. Food can be regarded as the second part P2. That is, the first portion P1 having the first physical characteristic and the second portion P2 having the second physical characteristic are not limited to the case where they exist as one in the article G, and may exist separately in, for example, one package. ..

When the first portion P1 and the second portion P2 exist separately, the first region corresponding to the first portion P1 is covered with the mask processing applied to the second region corresponding to the second portion P2. By carrying out the first treatment, it is determined whether or not the first portion P1 contains the foreign matter F, and the second portion P2 is in a state where the first region corresponding to the first portion P1 is masked. It is effective to determine whether or not the second portion P2 contains the foreign matter F by performing the second treatment on the second region corresponding to the above. Further, for example, when the content is contained as an inspection target in a container whose X-ray attenuation characteristic is different from that of the content, a mask treatment is applied to the area corresponding to the edge, partition, etc. of the container. After the application, it can be determined whether or not the content contains a foreign substance F.

Further, the control unit 10 calculates a multiplier for matching the luminance value LL of the X-rays in the low energy band with the luminance value LH of the X-rays in the high energy band at the same frequency F, and calculates the multiplier for all the frequencies. By carrying out the above, the relationship between the luminance value of the X-ray in the low energy band and the multiplier may be acquired and the relationship may be stored. In that case, the control unit 10 corrects the brightness value by multiplying the detection result of the low energy band X-rays acquired for the first portion P1 by a multiplier for each brightness value, and corrects the corrected low energy band X-rays. The first process of taking the difference between the detection result and the detection result of the X-ray in the high energy band acquired for the first portion P1 is performed for each pixel. Further, the control unit 10 corrects the brightness value by multiplying the detection result of the low energy band X-rays acquired for the second portion P2 by a multiplier for each brightness value, and detects the corrected low energy band X-rays. The second process of taking the difference between the result and the detection result of the X-ray in the high energy band acquired for the second portion P2 is performed for each pixel.

It is also possible to inspect an article G containing three or more parts having three or more different physical properties from each other. Even in that case, it is sufficient to prepare in advance a process for combining the detection result of the high energy band X-ray and the detection result of the low energy band X-ray for each portion.

1 ... X-ray inspection device, 6 ... X-ray irradiation unit, 7 ... X-ray detection unit, 10 ... Control unit (processing unit), G ... Article, P1 ... 1st part, P2 ... 2nd part, F ... Foreign matter.

Claims (3)

An X-ray irradiation unit that irradiates an article containing a first portion having a first physical property and a second portion having a second physical property with X-rays.
An X-ray detector that detects X-rays in the first energy band that has passed through the article and X-rays in the second energy band that has passed through the article.
Based on the first detection result of X-rays in the first energy band and the second detection result of X-rays in the second energy band, a processing unit for determining whether or not the article contains foreign matter, and a processing unit. Equipped with
The processing unit
The result obtained by multiplying one of the first detection result and the second detection result acquired for the article by the first multiplier for each brightness value and correcting the brightness value, the first detection result and the above. By performing the first process of taking the difference between the second detection result and the other for each pixel, it is determined whether or not the foreign matter is contained in the first portion.
The result obtained by multiplying one of the first detection result and the second detection result acquired for the article by a second multiplier for each brightness value to correct the brightness value, the first detection result and the above. By performing the second process of taking the difference between the second detection result and the other for each pixel, it is determined whether or not the foreign matter is contained in the second portion.
The first multiplier is a histogram of the luminance value in the X-ray transmission image of the first energy band previously acquired for the first portion, and the X-ray transmission of the second energy band previously acquired for the first portion. In the luminance value histogram in the image, each frequency corresponds to a multiplier for matching the luminance value of the X-ray in the second energy band and the luminance value of the X-ray in the first energy band .
The second multiplier is a histogram of the luminance value in the X-ray transmission image of the first energy band previously acquired for the second portion, and the X-ray transmission of the second energy band previously acquired for the second portion. in the histogram of luminance values in the image, for each frequency, it corresponds to multiplier for combining the luminance values of the X-ray intensity value from the first energy band of the X-ray of the second energy band, X-ray examination apparatus .. The processing unit
By performing the first treatment on the region corresponding to the entire article using the first detection result and the second detection result acquired for the article, the foreign matter is contained in the first portion. Judge whether or not it is
By performing the second treatment on the region corresponding to the entire article using the first detection result and the second detection result acquired for the article, the foreign matter is contained in the second portion. The X-ray inspection apparatus according to claim 1, wherein it is determined whether or not the X-ray is used. The processing unit
Based on at least one of the first detection result and the second detection result acquired for the article, the first region corresponding to the first portion and the second region corresponding to the second portion in the article are defined. Extract and
Whether or not the foreign matter is contained in the first portion by performing the first treatment on the first region using the first detection result and the second detection result acquired for the article. Judging,
Whether or not the foreign matter is contained in the second portion by performing the second treatment on the second region using the first detection result and the second detection result acquired for the article. The X-ray inspection apparatus according to claim 1.

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