X-ray inspection device

Abstract

To provide an X-ray inspection device capable of detecting a quality-deteriorated article with good accuracy.SOLUTION: An X-ray inspection device 1 comprises: an X-ray irradiation unit 6 for irradiating an article G with an X ray; an X-ray detection unit 7 for detecting the X ray; and a control unit 10 for inspecting the article G on the basis of an X-ray transmission image created from the detection result of the X ray detected by the X-ray detection unit 7. The control unit 10 determines that the quality of the article G is low when a quality index value calculated on the basis of the area of a region of the X-ray transmission image where the article G exists and the contrasting density of the X-ray transmission image is larger than a threshold.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] One aspect of the present invention relates to an X-ray inspection apparatus. [Background technology]

[0002] There is known an X-ray inspection device that includes an X-ray irradiation unit that irradiates an object with X-rays, an X-ray detection unit that detects the X-rays, and an inspection unit that inspects the object based on an X-ray transmission image created from the detection results of the X-rays detected by the X-ray detection unit. For example, Patent Document 1 discloses an X-ray inspection device that determines an object to be defective when the range of pixels in an X-ray transmission image where the brightness of each pixel is less than a first threshold value and equal to or greater than a second threshold value is equal to or greater than a predetermined range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7393793 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when at least a portion of an item such as meat is harder than a non-defective item, it may be treated as a low-quality item (hereinafter also referred to as a "low-quality item"). For this reason, there is a demand for the above-mentioned X-ray inspection device to be able to detect foreign matter mixed into an item, as well as to be able to accurately detect low-quality items. This demand is particularly pronounced in recent years, as "woody breast," which is unnaturally hardened chicken breast meat, has become a problem.

[0005] Therefore, an object of one aspect of the present invention is to provide an X-ray inspection device that can accurately detect articles whose quality has deteriorated. [Means for solving the problem]

[0006] After extensive research, the inventors discovered that the following differences may occur in X-ray images created from the detection results of X-rays transmitted through an object between a good product and a low-quality product, at least some of which are harder than the good product. That is, a good product is transported in a sagging, spread-out state due to its own weight, and tends to appear thin and large in the X-ray image. In contrast, a low-quality product is transported in a contracted, lumpy state due to its hardness, and tends to appear dark and small in the X-ray image. Based on this discovery, the inventors discovered that an X-ray inspection device can accurately detect low-quality products, and thus conceived one aspect of the present invention.

[0007] (1) One aspect of the present invention is an X-ray inspection device that includes an X-ray irradiation unit that irradiates an object with X-rays, an X-ray detection unit that detects the X-rays, and an inspection unit that inspects the object based on an image created from the detection results of the X-rays detected by the X-ray detection unit, and the inspection unit determines that the quality of the object is low if a quality index value calculated based on the area of ​​the area in the image where the object is present and the shading of the image or the weight of the object is greater than a threshold value.

[0008] This X-ray inspection system makes use of the above-mentioned knowledge that good products tend to appear thin and large in X-ray images, while low-quality products that are harder than good products tend to appear dark and small in X-ray images, making it possible to accurately detect low-quality products.

[0009] (2) In the X-ray inspection device described in (1) above, the inspection unit may calculate the quality index value by dividing the weight estimated from the shading of the region by the area of ​​the region. In this case, the above knowledge can be effectively utilized to more accurately detect low-quality products.

[0010] (3) In the X-ray inspection device described in (1) above, the inspection unit may calculate the quality index value by dividing the weight estimated from the density of the dark portion by the area of ​​the dark portion where the density in the region is darker than a certain value. In this case, it becomes possible to accurately detect low-quality products that partially include parts harder than good products.

[0011] (4) The X-ray inspection device described in (1) to (3) above may further include a detection unit that detects the height of an article, and the inspection unit may calculate the volume of the region based on the height of the article and the area of ​​the region detected by the detection unit, and calculate a quality index value based on the volume of the region and the shading of the image or the weight of the article. In this case, the quality index value can be calculated taking into account the volume of the article, making it possible to more accurately detect low-quality products.

[0012] (5) In the X-ray inspection device described in any one of (1) to (4) above, the product may include chicken breast, and the inspection unit may determine that the product is of low quality and that the product contains woody breast. In this case, higher quality chicken breast can be shipped. [Effects of the Invention]

[0013] According to one aspect of the present invention, it is possible to provide an X-ray inspection device that can accurately detect articles whose quality has deteriorated. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a configuration diagram showing an X-ray inspection apparatus according to an embodiment. [Figure 2] FIG. 2 is a configuration diagram showing the inside of the shielding box of FIG. [Figure 3] FIG. 3 is a block diagram showing the functional configuration of the control unit in FIG. [Figure 4] Fig. 4(a) is a diagram showing an example of an X-ray transmission image of a non-defective product, and Fig. 4(b) is a diagram showing an example of an X-ray transmission image of a missing product. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals and redundant description will be omitted.

[0016] As shown in FIG. 1, the X-ray inspection device 1 generates an X-ray transmission image of the item G while transporting the item G, and inspects the item G based on the X-ray transmission image. The item G before inspection is carried into the X-ray inspection device 1 by a carry-in conveyor 51. The item G after inspection is carried out from the X-ray inspection device 1 by a carry-out conveyor 52. The item G is a product having a certain size. The item G is not particularly limited, but may include meat, for example. In this embodiment, the item G may include chicken breast meat.

[0017] The X-ray inspection apparatus 1 has an apparatus main body 2, support legs 3, a shielding box 4, a transport unit 5, an X-ray irradiation unit 6, an X-ray detection unit 7, a display operation unit 8, and a control unit 10. The apparatus main body 2 houses the control unit 10 and the like. The support legs 3 support the apparatus main body 2. The shielding box 4 is provided on the apparatus main body 2. The shielding box 4 prevents leakage of X-rays (electromagnetic waves) to the outside. An inspection area R is provided inside the shielding box 4 where inspection of an item G using X-rays is performed. The shielding box 4 is formed with an inlet 4a and an outlet 4b. The transport unit 5 transports the item G. In the illustrated example, the transport unit 5 transports the item G from the inlet 4a of the shielding box 4 through the inspection area R to the outlet 4b in a transport direction A. The transport unit 5 is, for example, a belt conveyor.

[0018] 1 and 2, the X-ray irradiator 6 is an X-ray source that irradiates X-rays onto the article G being conveyed by the conveyor 5. The X-ray irradiator 6 is disposed inside the shield box 4. The X-ray irradiator 6 includes, for example, an X-ray tube that emits X-rays, and a diaphragm that spreads the X-rays emitted from the X-ray tube in a fan shape in a plane perpendicular to the conveyance direction A. The X-rays irradiated from the X-ray irradiator 6 may include X-rays in various energy bands ranging from low energy (long wavelength) to high energy (short wavelength).

[0019] The X-ray detection unit 7 is a sensor member that detects X-rays that have been irradiated by the X-ray irradiation unit 6 and transmitted through the object G. The X-ray detection unit 7 may be a line sensor or a group of sensors arranged two-dimensionally. The display operation unit 8 is provided in the device main body 2. The display operation unit 8 displays various information and accepts input operations of various conditions from the outside. 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.

[0020] The control unit 10 controls the operation of each unit of the X-ray inspection apparatus 1. The control unit 10 includes a processor such as a CPU (Central Processing Unit), memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and storage such as an SSD (Solid State Drive). The ROM stores a program for controlling the X-ray inspection apparatus 1. The control unit 10 constitutes an inspection unit that inspects an item based on an X-ray transmission image (image) created from the detection results of X-rays detected by the X-ray detection unit 7.

[0021] As shown in FIG. 3, the control unit 10 has an image generation unit 11, a quality index value calculation unit 12, and a quality judgment unit 13. In the control unit 10, the image generation unit 11, the quality index value calculation unit 12, and the quality judgment unit 13 are configured as software. However, each of these units may be configured as hardware. The image generation unit 11 generates an X-ray transmission image of the article G based on the detection result by the X-ray detection unit 7. The quality index value calculation unit 12 calculates a quality index value, which is a value that serves as an index of the quality of the article G, based on the area of ​​the region where the article G exists in the generated X-ray transmission image and the shading of the X-ray transmission image.

[0022] As an example, the quality index value calculation unit 12 calculates the area of ​​the region in the X-ray image where the item G exists (hereinafter also referred to as the "item region") by, for example, image processing the X-ray image (such as binarizing at a predetermined percentage). Furthermore, since heavier substances tend to appear darker on the X-ray image, the quality index value calculation unit 12 estimates the weight of each pixel from the shade of each pixel in the item region of the X-ray image and adds up these weights to estimate the weight of the item G. The quality index value calculation unit 12 then calculates the quality index value by dividing the weight of the item G by the area of ​​the item region.

[0023] If the calculated quality index value is greater than a threshold, the quality determination unit 13 determines that the quality of the item G is low. Specifically, if the calculated quality index value is greater than a threshold, the quality determination unit 13 determines that the item G being the subject of quality determination is a low-quality item in which at least a portion is harder than a good item (normal item). In this embodiment, the quality determination unit 13 determines that the quality of the item G is low and that the item G contains woody breast (that is, determines that the item G is a low-quality item that contains woody breast).

[0024] The threshold value may be set in advance and stored in the control unit 10. The threshold value may be set for each type of item G. The threshold value may be a fixed value or a variable value that can be changed by the user via the display operation unit 8, etc. Woody breast is chicken breast meat that has become unnaturally tough. Woody breast is chicken breast meat that has become as hard as wood. Woody breast is chicken breast meat with a gritty texture and is more likely to occur in large chickens. Woody breast is fibrous (stringy) chicken breast meat. Woody breast is also called wood breast.

[0025] When the quality determination unit 13 determines that the quality of the item G is not low, the control unit 10 causes the display operation unit 8 to display the generated X-ray image 31 and a message indicating that the item G is OK (a non-defective product) (see FIG. 4(a)). When the quality determination unit 13 determines that the quality of the item G is low, the control unit 10 causes the display operation unit 8 to display the generated X-ray image 31 and a message indicating that the item G is NG and out of stock (a low-quality product) (see FIG. 4(b)).

[0026] Here, we have learned that the following differences can occur in X-ray images between good products and low-quality products, at least some of which are harder than good products. That is, good products are transported in a sagging, spread-out state due to their own weight, and tend to appear thin and large in X-ray images. In contrast, low-quality products are transported in a shrunk, lumpy state due to their hardness, and tend to appear dark and small in X-ray images.

[0027] Therefore, in the X-ray inspection device 1, the control unit 10 determines that the quality of the article G is low if the quality index value calculated based on the area of ​​the article region in the X-ray transmission image 31 and the shading of the image is greater than a threshold value. This makes it possible to accurately detect low-quality articles by utilizing the above-mentioned knowledge that good articles tend to appear thin and large in X-ray transmission images, and that low-quality articles that are harder than good articles tend to appear dark and small in X-ray transmission images.

[0028] In the X-ray inspection apparatus 1, the quality index value calculation unit 12 of the control unit 10 calculates the quality index value by dividing the weight estimated from the shading of the item region by the area of ​​the item region. In this case, the quality index value corresponds to the weight of the item G per unit area of ​​the item region. Therefore, since woody breast is packed into a smaller area than good products, low-quality products containing woody breast will have a large quality index value. Therefore, in this case, by effectively utilizing the above-mentioned knowledge, it is possible to more accurately detect the low-quality products.

[0029] In the X-ray inspection device 1, the item G contains chicken breast meat, and the control unit 10 determines that the quality of the item G is low and that the item G contains woody breast meat. In this case, low-quality items containing woody breast meat can be identified and prevented from being shipped. In other words, high-quality chicken breast meat can be shipped.

[0030] Although the embodiments have been described above, one aspect of the present disclosure is not limited to the above-described embodiments.

[0031] In the above embodiment, the weight of the article G may be measured by a weighing device separate from the X-ray inspection apparatus 1. In this case, the quality index value calculation unit 12 of the control unit 10 may calculate the quality index value based on the area of ​​the article region in the X-ray transmission image and the measured weight.

[0032] In the above embodiment, the quality index value calculation unit 12 of the control unit 10 may calculate the quality index value by dividing the weight estimated from the shade of the dark portion by the area of ​​the dark portion in the article region of the X-ray transmission image, where the shade is darker than a certain value. In this case, it becomes possible to accurately detect low-quality products that partially contain parts harder than good products (such as woody press).

[0033] The above embodiment may further include a detection unit that detects the height of the item G being transported by the transport unit 5. In this case, the quality index value calculation unit 12 of the control unit 10 may calculate the volume of the item G based on the height of the item G detected by the detection unit and the area of ​​the item region, and may calculate the quality index value based on the volume of the item G and the shading of the X-ray image or the weight of the item G. In this case, the quality index value corresponds to, for example, the weight per unit volume of the item G. Therefore, the quality index value can be calculated taking into account the volume of the item G, making it possible to more accurately detect low-quality products.

[0034] In the above embodiment, if the calculated quality index value is smaller than the lower threshold (another threshold), the quality judgment unit 13 of the control unit 10 may judge that the item G being subjected to quality judgment is a low-quality product, such as one that contains parts that are too soft, has a sparse interior, has a lot of fatty parts, or has a poor balance between lean meat and fatty meat.

[0035] In the above embodiment, the control unit 10 may determine whether the quality of the article G is low by the following separate process. That is, the control unit 10 performs a first process of determining the presence or absence of foreign matter in the article G using the brightness of each pixel in the X-ray image and a first threshold value related to foreign matter inspection of the article G, and a second process of determining the quality of the article G using the brightness of each pixel in the X-ray image and a second threshold value lower than the first threshold value related to quality inspection of the article G. In the second process, the control unit 10 may determine that the quality of the article G is low if the range of pixels whose brightness is less than the first threshold value and equal to or greater than the second threshold value is equal to or greater than a predetermined range. Alternatively, the control unit 10 may perform a binarization process on the X-ray image based on the brightness value that is less than the first threshold value and equal to or greater than the second threshold value, obtain the area of ​​a region in the binarized image, and determine that the quality of the article G is low if the area of ​​the region is equal to or greater than a predetermined area.

[0036] In this case, if the quality determination unit 13 determines that the quality of the item G is low and if the quality of the item G is also determined to be low by the separate process, it may be determined that there is a very high possibility that the item G is a low-quality item (including Woody Breast). Also, if the quality of the item G is determined to be low by only either the quality determination unit 13 or the separate process, it may be determined that there is a high possibility that the item G is a low-quality item. If the quality of the item G is not determined to be low by either the quality determination unit 13 or the separate process, it may be determined that the item G is a good item (low possibility that it is a low-quality item).

[0037] The respective components in the above-described embodiment and modified examples are not limited to the materials and shapes described above, and various materials and shapes can be applied. Furthermore, the respective components in the above-described embodiment and modified examples can be arbitrarily applied to the respective components in other embodiments or modified examples. [Explanation of symbols]

[0038] 1...X-ray inspection device, 6...X-ray irradiation unit, 7...X-ray detection unit, 10...control unit (inspection unit), 31...X-ray transmission image (image), G...item.

Claims

1. an X-ray irradiation unit that irradiates an object with X-rays; an X-ray detection unit that detects the X-rays; an inspection unit that inspects the item based on an image created from a detection result of the X-rays detected by the X-ray detection unit, The inspection unit An X-ray inspection device that determines that the quality of the item is low if a quality index value calculated based on the area of ​​the area in the image where the item exists and the shading of the image or the weight of the item is greater than a threshold value.

2. The X-ray inspection apparatus according to claim 1 , wherein the inspection unit calculates the quality index value by dividing a weight estimated from the shading of the region by an area of ​​the region.

3. 2. The X-ray inspection apparatus according to claim 1, wherein the inspection unit calculates the quality index value by dividing a weight estimated from the density of the dark portion by an area of ​​the dark portion in the region that is darker than a certain value.

4. Further provided is a detection unit that detects the height of the article, The inspection unit calculating a volume of the object based on the height of the object detected by the detection unit and the area of ​​the region; The X-ray inspection apparatus according to claim 1 , wherein the quality index value is calculated based on the volume of the item and the shading of the image or the weight of the item.

5. the article comprises a chicken breast; The X-ray inspection apparatus according to claim 1 , wherein the inspection unit determines that the item is of low quality and that the item contains woody breast.

Images