X-ray inspection device

Abstract

The X-ray inspection apparatus includes: a transport unit that transports an article in a transport direction; an irradiation unit that irradiates X-rays on the article conveyed by the conveyance unit; a sensor unit having a plurality of detection elements that detect X-rays and are arranged in a planar shape; an image generation unit that generates an image on the basis of a detection result output from the sensor unit; and an inspection unit that inspects the article on the basis of the image, the plurality of detection elements including: first detection elements arranged in a first row in an intersecting direction intersecting the conveying direction; and second detection elements arranged in a second row parallel to the first row, the number of the second detection elements arranged in the second row being greater than the number of the first detection elements arranged in the first row.

Description

Technical Field

[0001] The present invention relates to an X-ray inspection apparatus. Background Art

[0002] Conventionally, as an apparatus for inspecting an object to be inspected (article) such as food or medicine, an inspection apparatus using electromagnetic waves such as X-rays has been used. For example, the non-destructive inspection apparatus described in Japanese Patent No. 6454820 includes: an electromagnetic wave irradiation unit that irradiates a predetermined electromagnetic wave to an inspection target object; a conveyance unit that conveys the inspection target object placed on a conveyance surface in the Y-axis direction; an electromagnetic wave detection unit that arranges a detection element group composed of M detection elements arranged in the Y-axis direction in N rows in the X-axis direction; and M×N wirings that electrically connect each of the M×N detection elements to a predetermined connection destination outside either end in the Y-axis direction of the electromagnetic wave detection unit. Summary of the Invention

[0003] In the non-destructive inspection apparatus described in Japanese Patent No. 6454820, a detection element group arranged in a lattice shape is used as the electromagnetic wave detection unit. In the case of using such an electromagnetic wave detection unit, when a foreign object passes between adjacent detection elements in the X-axis direction, the foreign object is not detected by all the detection elements, and there is a possibility of missed detection of the foreign object. In order to prevent such missed detection, for example, it is considered to increase the integration degree of the detection elements in the detection element group. However, if only the integration degree of the detection elements is increased, the manufacturing cost of the electromagnetic wave detection unit will increase excessively.

[0004] An object of one aspect of the present invention is to provide an X-ray inspection apparatus that can suppress an increase in manufacturing cost and can suppress missed detection of foreign objects.

[0005] (1) The X-ray inspection apparatus according to one aspect of the present invention includes: a conveyance unit that conveys an article along a conveyance direction; an irradiation unit that irradiates the article conveyed by the conveyance unit with X-rays; a sensor unit that has a plurality of detection elements that detect X-rays and are arranged in a planar shape; an image generation unit that generates an image based on a detection result output from the sensor unit; and an inspection unit that inspects the article based on the image. The plurality of detection elements include: a first detection element arranged in a first row in a crossing direction crossing the conveyance direction; and a second detection element arranged in a second row parallel to the first row, and the number of the second detection elements arranged in the second row is larger than the number of the first detection elements arranged in the first row.

[0006] According to the X-ray inspection apparatus, the plurality of detection elements included in the sensor unit include: a first detection element arranged in a first column in a crossing direction crossing the conveying direction; and a second detection element arranged in a second column juxtaposed with the first column, and the number of second detection elements arranged in the second column is larger than the number of first detection elements arranged in the first column. Therefore, the second detection element is smaller than the first detection element, and foreign matter passing through the sensor unit is easily detected by the plurality of second detection elements in the second column. Therefore, omission detection of foreign matter is less likely to occur. In addition, by including both the first detection element and the second detection element in the sensor unit, an increase in the manufacturing cost of the sensor unit can be suppressed as compared with the case where the sensor unit only has the second detection element.

[0007] (2) In the X-ray inspection apparatus described in (1) above, the image includes a first pixel and a second pixel, and the image generation unit may also generate the first pixel using the detection result of the first detection element and generate the second pixel using the detection results of the plurality of second detection elements. In this case, the contrast of the image generated by the image generation unit can be improved.

[0008] (3) In the X-ray inspection apparatus described in (1) above, the image may also include: a first image including first pixels generated using the detection results of the first detection elements; and a second image including second pixels generated using the detection results of the plurality of second detection elements. In this case, the differences in brightness, contrast, etc. between the first image and the second image can be suppressed.

[0009] (4) In the X-ray inspection apparatus described in (2) or (3) above, when two adjacent detection elements among the first detection elements arranged in the first column are respectively used as a third detection element and a fourth detection element, a part of the plurality of second detection elements for generating the second pixel may be arranged in the conveying direction with respect to the third detection element, and another part of the plurality of second detection elements for generating the second pixel may be arranged in the conveying direction with respect to the fourth detection element. In this case, foreign matter between the third detection element and the fourth detection element is easily displayed on the second pixel generated using the detection results of the plurality of second detection elements. Therefore, omission detection of foreign matter is less likely to occur satisfactorily.

[0010] (5) In the X-ray inspection apparatus according to any one of (1) to (4) above, the size of the first detection element in the conveying direction may be the same as the size of the second detection element in the conveying direction, and the size of the first detection element in the crossing direction is a natural number multiple of 2 or more of the size of the second detection element in the crossing direction. In this case, omission detection of foreign matter is less likely to occur satisfactorily.

[0011] (6) In the X-ray inspection apparatus according to any one of (1) to (5) above, the first column and the second column may also be alternately arranged in multiple columns along the conveying direction. In this case, it is less likely that foreign objects are missed in detection.

[0012] (7) The X-ray inspection apparatus according to another aspect of the present invention includes: a conveying unit that conveys an article along the conveying direction; an irradiation unit that irradiates the article conveyed by the conveying unit with X-rays; a sensor unit that has a plurality of detection elements configured in a planar shape and that detect X-rays; an image generation unit that generates an image based on the detection results output from the sensor unit; and an inspection unit that inspects the article based on the image. The plurality of detection elements include: a first detection element arranged in a first column in a crossing direction that crosses the conveying direction; and a second detection element arranged in a second column that is juxtaposed with the first column. When viewed from the conveying direction, a second detection element is disposed at a position corresponding to a position between two adjacent first detection elements in the first column.

[0013] According to this X-ray inspection apparatus, the plurality of detection elements included in the sensor unit include: a first detection element arranged in a first column in a crossing direction that crosses the conveying direction; and a second detection element arranged in a second column that is juxtaposed with the first column. When viewed from the conveying direction, a second detection element is disposed at a position corresponding to a position between two adjacent first detection elements in the first column. Thus, even without increasing the integration degree of the sensor unit, foreign objects in the gaps between adjacent first detection elements also pass through any one of the second detection elements. Therefore, an increase in the manufacturing cost of the sensor unit is suppressed, and it is less likely that foreign objects are missed in detection.

[0014] According to one aspect of the present invention, an X-ray inspection apparatus capable of suppressing an increase in manufacturing cost and suppressing missed detection of foreign objects can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural diagram of an X-ray inspection apparatus according to an embodiment.

[0016] Figure 2 is Figure 1 a schematic structural diagram of the inside of the shielding box shown.

[0017] Figure 3 is a schematic top view of a main part of the sensor unit.

[0018] Figure 4 is a functional structural diagram of the control unit.

[0019] Figure 5 (a) of is a schematic top view showing a first example of a combination of a plurality of second detection elements. Figure 5(b) is a schematic top view showing a second example of a combination of a plurality of second detection elements.

[0020] Figure 6 is a schematic top view of a main part of a sensor unit according to a modified example.

[0021] Explanation of reference numerals

[0022] 1: X-ray inspection apparatus; 3: support leg; 4: shielding box; 4a: loading port; 4b: unloading port; 5: conveying unit; 6: X-ray irradiation unit; 7: sensor unit; 8: display operation unit; 9: control unit; 10: detection element; 11: first detection element; 11a: third detection element; 11b: fourth detection element; 12: second detection element; 21: receiving unit; 22: image generation unit; 23: inspection unit; 24: determination unit; 25: output unit; 26: recording unit; A: conveying direction; G: article. Detailed description of the preferred embodiments

[0023] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0024] As Figure 1 shown, the X-ray inspection apparatus 1 includes a device main body 2, support legs 3, a shielding box 4, a conveying unit 5, an X-ray irradiation unit 6, a sensor unit 7, a display operation unit 8, and a control unit 9. The X-ray inspection apparatus 1 conveys an article G, generates an X-ray transmission image of the article G, and inspects the article G based on the X-ray transmission image. The article G before inspection is carried into the X-ray inspection apparatus 1 by a loading conveyor 51. The article G after inspection is carried out of the X-ray inspection apparatus 1 by an unloading conveyor 52.

[0025] The device main body 2 houses the control unit 9 and the like. The support legs 3 support the device main body 2. The shielding box 4 is provided on the device main body 2. The shielding box 4 is a housing that prevents X-rays (electromagnetic waves) from leaking to the outside. An inspection chamber R for inspecting the article G using X-rays is provided inside the shielding box 4. A loading port 4a and an unloading port 4b are formed in the shielding box 4. The article G before inspection is carried into the inspection chamber R from the loading conveyor 51 through the loading port 4a. The article G after inspection is carried out of the inspection chamber R through the unloading port 4b to the unloading conveyor 52.

[0026] The conveying unit 5 is a component for conveying the article G, and is arranged so as to penetrate the center of the shielding box 4. The conveying unit 5 conveys the article G from the loading port 4a to the unloading port 4b via the inspection chamber R along the conveying direction A. The speed (conveying speed) at which the article G is conveyed by the conveying unit 5 is set by the control unit 9, for example. The conveying unit 5 is, for example, a belt conveyor installed between the loading port 4a and the unloading port 4b. Additionally, the conveying unit 5 may protrude more outward than the loading port 4a and the unloading port 4b.

[0027] As Figure 1 and Figure 2 shown, the X-ray irradiation unit 6 is an electromagnetic wave irradiation unit arranged inside the shielding box 4, and irradiates the article G conveyed by the conveying unit 5 with X-rays. The X-rays include X-rays in various energy regions from low energy (long wavelength) to high energy (short wavelength). Therefore, the X-ray irradiation unit 6 irradiates the article G conveyed to the conveying unit 5 with X-rays in multiple energy regions. It is also possible to perform X-ray irradiation using the X-ray irradiation unit 6 (i.e., idling of the X-ray irradiation unit 6) after the X-ray inspection apparatus 1 is started and before the article G is inspected. Additionally, the "low" and "high" in the above-mentioned low energy and high energy indicate relatively "low" and "high" energy regions among the multiple energy regions irradiated by the X-ray irradiation unit 6, and do not represent a specific range. Furthermore, the electric power (especially the current) supplied to the X-ray irradiation unit 6 can be changed manually or automatically. By changing this electric power, the output of the X-rays irradiated onto the article G can be changed. Thereby, it is possible to irradiate X-rays having an appropriate intensity corresponding to the article G.

[0028] The sensor unit 7 is a sensor unit for detecting electromagnetic waves. The sensor unit 7 is arranged inside the shielding box 4 at a position opposite to the X-ray irradiation unit 6 in the vertical direction. In the vertical direction, the conveying unit 5 is located between the sensor unit 7 and the X-ray irradiation unit 6. Figure 3 is a schematic top view of the main part of the sensor unit 7. As Figure 3 shown, the sensor unit 7 has a plurality of detection elements 10 for detecting X-rays and arranged in a planar shape (two-dimensional). The detection elements 10 are arranged at least in a direction (crossing direction) crossing the conveying direction A of the conveying unit 5.

[0029] In the present embodiment, the sensor unit 7 is a direct conversion type detection unit capable of detecting X-rays in a photon counting manner. Further, the detection element 10 is, for example, a sensor (multi-energy sensor) that detects X-rays in each of a plurality of energy regions of the transmitted article G, and the sensor unit 7 may also be a time delay integration sensor (TDI sensor: Time Delay Integration sensor). The detection element 10 includes, for example, a photon detection type sensor such as a CdTe semiconductor detector. In the detection element 10, for example, electron-hole pairs are generated by the arrival of X-ray photons. At this time, based on the obtained energy (photon energy), photon counting processing (photon counting) is performed. This counting processing is performed, for example, by an arithmetic unit (not shown) included in the sensor unit 7 or the detection element 10. The results (detection results) of the above counting processing of each detection element 10 based on the arithmetic unit are output to the control unit 9 at predetermined time intervals. This predetermined time is a time (default time) predetermined in the X-ray inspection apparatus 1. In addition, the interval of the above predetermined time is also referred to as a readout interval or a delay time, and can be appropriately changed by the control unit 9.

[0030] Each detection element 10 of the sensor unit 7 may also discriminate the photon energy of X-rays detected based on an arbitrary threshold into two or more energy regions. In this case, the sensor unit 7 can perform photon counting for each energy region. The arbitrary threshold is, for example, one or more values (unit: keV) set by the control unit 9. The arbitrary threshold can be set, for example, by the method described in Japanese Unexamined Patent Application Publication No. 2023-132587, or can be set using the following luminance level.

[0031] The plurality of detection elements 10 include a first detection element 11 arranged on a first column C1 in the above-described crossing direction and a second detection element 12 arranged on a second column C2 juxtaposed with the first column C1. Therefore, on the first column C1, the plurality of first detection elements 11 are arranged along the above-described crossing direction, and on the second column C2, the plurality of second detection elements 12 are arranged along the above-described crossing direction. In the sensor unit 7, a plurality of first columns C1 and a plurality of second columns C2 are alternately provided in multiple columns along the conveyance direction A. In other words, in the sensor unit 7, a plurality of first columns C1 and a plurality of second columns C2 are set, and the first column C1 and the second column C2 are alternately arranged in the conveyance direction A. Therefore, in the conveyance direction A, the first detection element 11 and the second detection element 12 are alternately arranged. Each of the first column C1 and the second column C2 may also function as an analog line sensor, for example.

[0032] In the present embodiment, the size D1 of the first detection element 11 in the conveying direction A is the same as the size D2 of the second detection element 12 in the conveying direction A, but it is not limited thereto. The size D3 of the first detection element 11 in the crossing direction is different from the size D4 of the second detection element 12 in the crossing direction. In the present embodiment, the size D3 is larger than the size D4. For example, the size D3 is a natural number multiple of 2 or more of the size D4. When the number of the first detection elements 11 on the first column C1 is the same as the number of the second detection elements 12 on the second column C2, the brightness, contrast, etc. of the image generated by using the above detection result output from the second column C2 may be significantly different from the image generated by using the above detection result output from the first column C1. Therefore, in the present embodiment, the number of the second detection elements 12 arranged on the second column C2 is larger than the number of the first detection elements 11 arranged on the first column C1. For example, the number of the second detection elements 12 arranged on the second column C2 is a natural number multiple of 2 or more of the number of the first detection elements 11 arranged on the first column C1. Alternatively, the value obtained by dividing the number of the second detection elements 12 arranged on the second column C2 by the number of the first detection elements 11 arranged on the first column C1 may be the same as the value obtained by dividing the size D3 by the size D4.

[0033] The size L1 of the gap G1 between the first detection elements 11 in the crossing direction may be the same as or different from the size L2 of the gap G2 between the second detection elements 12 in the crossing direction. In the present embodiment, the size L1 is larger than the size L2. In this case, when observed from the conveying direction A, a part of the second detection element 12 overlaps with the gap G1. For example, when observed from the conveying direction A, a part of two adjacent second detection elements 12 overlaps with the gap G1. Thereby, even when a foreign object only passes through the gap G1, the foreign object can pass through one or more second detection elements 12. Alternatively, even when the sizes L1 and L2 are the same, a part of the second detection element 12 may overlap with the gap G1 when observed from the conveying direction A. That is, regardless of the relationship between the sizes L1 and L2, the first detection element 11 may overlap with a plurality of second detection elements 12 in the conveying direction A.

[0034] When the X-ray inspection apparatus 1 is started up, sensitivity calibration of the sensor unit 7 can be performed. In this sensitivity calibration, the luminance level is obtained based on the X-rays that have not passed through the object G. The luminance level is the number of photon counts detected when the X-rays that have not passed through the object G are incident on the sensor unit 7, and corresponds to the intensity of the detection signal included in the above detection result. The sensitivity calibration of the sensor unit 7 corresponds to the calibration of the output difference between the first detection elements 11 and the calibration of the output difference between the second detection elements 12. From the viewpoint of shortening the start-up time of the X-ray inspection apparatus 1, in the above sensitivity calibration, it is also possible to start the X-ray irradiation by the X-ray irradiation unit 6 simultaneously with the start of the detection of the X-rays by the sensor unit 7. In addition, the sensitivity calibration of the sensor unit 7 is performed, for example, by the method described in Japanese Patent Application No. 2023-39353. In the present embodiment, from the viewpoint of improving the contrast of the image generated by the X-ray inspection apparatus 1, it is confirmed whether the highest luminance level obtained in the sensitivity calibration is lower than a specified threshold value. That is, it is confirmed whether the maximum intensity of the detection signal included in the detection result output from at least a part of the plurality of detection elements 10 obtained in the sensitivity calibration is lower than the specified intensity. The result of this confirmation is output to the control unit 9.

[0035] As Figure 1 shown, the display operation unit 8 is a component (display unit) provided on the apparatus 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 that is a touch panel. In this case, the operator can input various conditions via the display operation unit 8. For example, the operator can set the conveyance speed of the conveyance unit 5, the power (at least one of current and voltage) supplied to the X-ray irradiation unit 6, etc. via the display operation unit 8. The input operation accepted by the display operation unit 8 is output to the conveyance unit 5, the sensor unit 7, the control unit 9, etc.

[0036] The control unit 9 is disposed inside the apparatus main body 2. The control unit 9 controls the operation of each part of the X-ray inspection apparatus 1. The control unit 9 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. Programs for controlling the X-ray inspection apparatus 1, the operation modes of the X-ray inspection apparatus 1, etc. are stored in the ROM.

[0037] Figure 4 is a functional structure diagram of the control unit. As Figure 4 shown, the control unit 9 includes a reception unit 21, an image generation unit 22, an inspection unit 23, a determination unit 24, an output unit 25, and a recording unit 26.

[0038] The receiving unit 21 receives the input operations accepted by the display operation unit 8. For example, the receiving unit 21 receives the conveyance speed of the conveyance unit 5 set via the display operation unit 8, etc. In addition, the receiving unit 21 receives the detection results output from the sensor unit 7 (specifically, the detection results of X-rays output from each detection element 10). The receiving unit 21 sends the received detection results to the image generation unit 22.

[0039] The image generation unit 22 is mainly composed of, for example, a GPU (Graphics Processing Unit), and generates an image based on the detection results output from the sensor unit 7. For example, the image generation unit 22 expands the signal of the received detection results into a two-dimensional image on a memory. The memory for expanding the two-dimensional image is, for example, a memory included in the GPU, but is not limited thereto. The image generation unit 22 reads out the above-mentioned detection results output from at least a part of the plurality of detection elements 10 included in the sensor unit 7 at a prescribed readout interval, and generates one or more time-delay integration images for inspecting the article G. For example, the image generation unit 22 generates a plurality of transmission images corresponding to each of the above-mentioned plurality of energy regions. In addition, the image generation unit 22 may generate one or more differential images based on the plurality of transmission images.

[0040] The image generation unit 22 can use, for example, an image processing algorithm or a program automatically set by machine learning. The image processing algorithm is composed of a combination of one image processing filter or a plurality of image processing filters. At least one or more of the plurality of image processing algorithms can adopt a genetic algorithm (GA = Genetic Algorithms), which is a technique applying the mechanisms of heredity and evolution in the biological world, and is automatically generated from a plurality of image processing filters based on the specifications or inspection conditions of the X-ray inspection apparatus 1, etc. At least a part of the plurality of image processing algorithms can also be appropriately set by an operator via the display operation unit 8. The program automatically set by machine learning is a prediction model (learned model) generated by machine learning, and is an inference program incorporating the parameters (learned parameters) obtained from the results of machine learning. Examples of machine learning for the learned model include neural networks, support vector machines, genetic algorithms, etc.

[0041] The image generated by the image generation unit 22 may also include an image (first image) generated using the detection result of the first detection element 11 and an image (second image) generated using the detection result of the second detection element 12. In this case, the image generation unit 22 generates the first image using the detection results output from each first column C1 in the sensor unit 7, and generates the second image using the detection results output from each second column C2 in the sensor unit 7. A pixel (first pixel) included in the first image is generated using, for example, the detection results of the first detection elements 11 with a specified serial number in one or more first columns C1. The first detection elements 11 with the specified serial number refer to the first detection elements 11 located at the specified serial number counted from one end of the first column C1 in the crossing direction. In the case where the detection element 10 is a TDI sensor, the above-mentioned first pixel is generated using the detection results of the first detection elements 11 with the specified serial number in each first column C1. A pixel (second pixel) included in the second image is generated using, for example, the detection results of a plurality of second detection elements 12 with a plurality of specified serial numbers in one or more second columns C2. That is, the second pixel sums up the detection results of two or more second detection elements 12 in one or more second columns C2 and is generated using the summed-up result. In the case where the detection element 10 is a TDI sensor, the above-mentioned second pixel is generated using the summed-up result of the detection results of a plurality of second detection elements 12 in each second column C2. The image generation unit 22 may also generate a difference image based on the above-mentioned first image and the above-mentioned second image.

[0042] It is sufficient that the plurality of second detection elements 12 used to generate the above-mentioned second pixel are arranged in sequence. Hereinafter, with reference to Figure 5 FIG. (a) of Figure 5 FIG., examples of combinations of a plurality of second detection elements will be described. Figure 5 FIG. (a) of Figure 5 FIG. is a schematic top view showing a first example of a combination of a plurality of second detection elements, Figure 5 FIG. (a) of Figure 5 FIG. (b) is a schematic top view showing a second example of a combination of a plurality of second detection elements. As shown in

[0043] FIG. Figure 5As shown in (a) above, in the first example, the second pixel is generated using the combined result of the detection results of the two second detection elements 12 surrounded by the frame ML1. Here, both of the two second detection elements 12 surrounded by the frame ML1 are arranged in the conveyance direction A with respect to the third detection element 11a. Accordingly, it is difficult to generate a difference between the image generated using the detection result output from the first column C1 and the image generated using the detection result output from the second column C2.

[0044] As Figure 5 As shown in (b) above, in the second example, the second pixel is generated using the combined result of the detection results of the two second detection elements 12 surrounded by the frame ML2. Here, one (a part) of the two second detection elements 12 surrounded by the frame ML2 is arranged in the conveyance direction A with respect to the third detection element 11a, and the other (the other part) of the two second detection elements 12 is arranged in the conveyance direction A with respect to the fourth detection element 11b. Accordingly, foreign matter in the article G in the gap G1 between the first detection elements 11 in the crossing direction is likely to be displayed by the pixel or the image generated using the detection result output from the second column C2.

[0045] In the present embodiment, the image generation unit 22 may generate a third image using all of the detection results output from the sensor unit 7 instead of or in addition to the first image and the second image described above. In this case, the third image includes the first pixel and the second pixel, and the image generation unit 22 generates the first pixel using the detection result of the first detection element 11 having a specified number, and generates the second pixel using the detection results of a specified plurality of second detection elements 12. The second pixel may be generated by the combination of the second detection elements 12 shown in the first example, or may be generated by the combination of the second detection elements 12 shown in the second example.

[0046] The inspection unit 23 inspects the article G based on the image generated by the image generation unit 22. For example, the inspection unit 23 inspects the article G using the plurality of transmission images, the difference image, etc. The inspection unit 23 may also inspect the article G based on both the difference image and the transmission image. In the generation of the difference image by the image generation unit 22, the inspection of the article G based on the transmission image or the like may also be performed. The inspection unit 23 inspects the article G for foreign matter, defects, etc., for example, but is not limited thereto. In the case where the article G is wrapped in a sheet-like packaging material, etc., the inspection unit 23 can also inspect for breakage of the packaging material, poor sealing (sealing bite) of the packaging material, etc. In the case where the article G is housed in a package, etc., the inspection unit 23 can perform a foreign matter confirmation inspection, a missing part confirmation inspection, a storage quantity confirmation inspection, a void confirmation inspection, etc. inside the package. The inspection unit 23 sends the inspection result of the article G to the determination unit 24 and the recording unit 26.

[0047] Based on the inspection results received from the inspection unit 23, the determination unit 24 determines whether the article G is a qualified product. For example, the determination unit 24 determines the presence or absence of foreign objects in the article G, whether there are defects in the article G, etc. The determination unit 24 sends the determination result to the output unit 25 and the recording unit 26.

[0048] The output unit 25 outputs the determination result of the determination unit 24 to at least one of the parts in the X-ray inspection apparatus 1 other than the control unit 9 and a device different from the X-ray inspection apparatus 1. Thus, at least one of the X-ray inspection apparatus 1 and a device different from the X-ray inspection apparatus 1 (for example, a distribution device arranged more downstream than the X-ray inspection apparatus 1) can perform an operation when the article G is a non-conforming product. As other examples of the above device different from the X-ray inspection apparatus 1, for example, an incoming conveyor 51, an outgoing conveyor 52, a notification device, etc. can be cited.

[0049] The recording unit 26 records signals, data, etc. generated by the control unit 9. For example, the recording unit 26 records the detection results sent from the receiving unit 21, the data of the images sent from the image generation unit 22, the data related to the inspection results sent from the inspection unit 23, and the data related to the determination results sent from the determination unit 24.

[0050] According to the X-ray inspection apparatus 1 according to the present embodiment described above, the plurality of detection elements 10 included in the sensor unit 7 include first detection elements 11 arranged on the first column C1 in the crossing direction and second detection elements 12 arranged on the second column C2 juxtaposed with the first column C1, and the number of the second detection elements 12 arranged on the second column C2 is larger than the number of the first detection elements 11 arranged on the first column C1. Therefore, the second detection elements 12 are smaller than the first detection elements 11, and foreign objects passing through the sensor unit 7 are easily detected by the plurality of second detection elements 12 on the second column C2. Therefore, it is not easy to miss the detection of the foreign objects. In addition, by including both the first detection elements 11 and the second detection elements 12 in the sensor unit 7, compared with the case where the sensor unit 7 only has the second detection elements 12, an increase in the manufacturing cost of the sensor unit 7 can be suppressed. In other words, compared with the case where only a plurality of second columns C2 are set in the sensor unit 7, an increase in the manufacturing cost of the sensor unit 7 can be suppressed.

[0051] In the present embodiment, the image includes first pixels and second pixels, and the image generation unit 22 may also generate first pixels using the detection results of the first detection elements 11 and generate second pixels using the detection results of the plurality of second detection elements 12. In this case, the contrast of the image generated by the image generation unit 22 can be improved.

[0052] In the present embodiment, the image may also include: a first image including first pixels generated based on the detection results of the first detection elements 11; and a second image including second pixels generated based on the detection results of the plurality of second detection elements 12. In this case, the differences in brightness, contrast, etc. between the first image and the second image can be suppressed.

[0053] In the present embodiment, it may also be that a part of the plurality of second detection elements 12 for generating the second pixels is arranged in the conveyance direction A with respect to the third detection element 11a, and another part of the plurality of second detection elements 12 for generating the second pixels is arranged in the conveyance direction A with respect to the fourth detection element 11b. In this case, foreign matter between the third detection element 11a and the fourth detection element 11b is likely to be displayed on the second pixels generated based on the detection results of the above-mentioned plurality of second detection elements 12. Therefore, it is well less likely to occur a missed detection of foreign matter.

[0054] In the present embodiment, the size D1 of the first detection element 11 in the conveyance direction A is the same as the size D2 of the second detection element 12 in the conveyance direction A, and the size D3 of the first detection element 11 in the crossing direction may also be a natural number multiple of 2 or more of the size D4 of the second detection element 12 in the crossing direction. In this case, since foreign matter passing through the sensor unit 7 is more likely to be detected by the plurality of second detection elements 12 on the second column C2, it is well less likely to occur a missed detection of foreign matter.

[0055] In the present embodiment, a plurality of columns of the first column C1 and the second column C2 are alternately provided along the conveyance direction A. Therefore, it is well less likely to occur a missed detection of foreign matter.

[0056] Figure 6 It is a schematic top view of the main part of the sensor unit according to the modified example. As Figure 6 shown, the difference between the sensor unit 7A of the present modified example and the sensor unit 7 of the above embodiment is that it includes a second column C2A instead of the second column C2. A plurality of second detection elements 12A arranged in the crossing direction are located on the second column C2A. The size D2A of the second detection element 12A in the conveyance direction A is the same as the size D1 of the first detection element 11, but is not limited thereto. In addition, the size D4A of the second detection element 12A in the crossing direction is the same as the size D3 of the first detection element 11, but is not limited thereto. In the present modified example, the size L2A of the gap G2A between the second detection elements 12A in the crossing direction is the same as the size L1 of the gap G1, but is not limited thereto.

[0057] In this modified example, the first detection element 11 and the second detection element 12A included in the sensor unit 7A are arranged in a so-called staggered pattern. For example, when viewed from the conveying direction A, on the first column C1, the second detection element 12A is arranged at a position corresponding to the position between two adjacent first detection elements 11. Similarly, when viewed from the conveying direction A, on the second column C2A, the first detection element 11 is arranged at a position corresponding to the position between two adjacent second detection elements 12A. In other words, in the conveying direction A, the gap G1 between the first detection elements 11 overlaps with any one of the second detection elements 12A, and the gap G2A between the second detection elements 12A overlaps with any one of the first detection elements 11. Further, when viewed from the conveying direction A, one first detection element 11 on a specified first column C1 overlaps with two second detection elements 12A on a second column C2 adjacent to the specified first column C1. Similarly, when viewed from the conveying direction A, one second detection element 12A on a specified second column C2 overlaps with two first detection elements 11 on a first column C1 adjacent to the specified second column C2.

[0058] According to the modified example described above, even if the integration degree of the sensor unit 7A is not increased, foreign matter on the gap G1 between adjacent first detection elements 11 also passes through any one of the second detection elements 12A. Therefore, an increase in the manufacturing cost of the sensor unit 7A is suppressed, and omission detection of foreign matter is less likely to occur.

[0059] As described above, the embodiments and modified examples of the present invention have been described, but the present invention is not necessarily limited to the above-described embodiments and modified examples, and various changes can be made without departing from the gist thereof. For example, in the above-described embodiment, the sensor unit is a device capable of detecting X-rays in a photon counting manner, but it is not limited thereto. The detection element included in the sensor unit may have at least a scintillator and a photodiode.

[0060] In each of the first example and the second example in the above-described embodiment, the second pixel is generated using the combined result of the detection results of two second detection elements, but the present invention is not limited thereto. For example, the second pixel may also be generated using the combined result of the detection results of three or more second detection elements. In this case, a part of the plurality of second detection elements for generating the second pixel may be arranged on the third detection element with respect to the conveying direction, and the other part of the plurality of second detection elements may be arranged on the fourth detection element with respect to the conveying direction.

Claims

1. An X-ray inspection device comprising: A conveying part, which conveys the articles along a conveying direction; an irradiation unit for irradiating the article conveyed by the conveying unit with X-rays; a sensor unit having a plurality of detection elements arranged in a plane for detecting the X-rays; an image generating unit that generates an image based on the detection result output from the sensor unit; as well as The inspection unit inspects the article based on the image. The plurality of detection elements include: first detection elements arranged in a first row in a direction intersecting the conveying direction; and a second detection element arranged in a second column parallel to the first column, The number of the second detection elements arranged in the second column is greater than the number of the first detection elements arranged in the first column.

2. The X-ray inspection apparatus according to claim 1, wherein: The image comprises a first pixel and a second pixel, The image generating unit: generating the first pixel using the detection result of the first detection element, The second pixel is generated using the detection results of the plurality of second detection elements.

3. The X-ray inspection apparatus according to claim 1, wherein: The image includes: a first image including first pixels generated using a detection result of the first detection element; and a second image including second pixels generated using detection results of a plurality of the second detection elements.

4. The X-ray inspection apparatus according to claim 2 or 3, wherein: When two adjacent detection elements among the first detection elements arranged in the first column are used as the third detection element and the fourth detection element, respectively, A part of the plurality of second detection elements for generating the second pixel is arranged in the transport direction relative to the third detection element, Another part of the plurality of second detection elements for generating the second pixel is arranged in the transport direction relative to the fourth detection element.

5. The X-ray inspection device according to any one of claims 1 to 3, wherein: The size of the first detection element in the conveying direction is the same as the size of the second detection element in the conveying direction, The size of the first detection element in the intersecting direction is a natural number multiple of 2 or more of the size of the second detection element in the intersecting direction.

6. The X-ray inspection device according to any one of claims 1 to 3, wherein: The first row and the second row are respectively arranged in a plurality of rows alternately along the conveying direction.

7. An X-ray inspection device comprising: A conveying part, which conveys the articles along a conveying direction; an irradiation unit for irradiating the article conveyed by the conveying unit with X-rays; a sensor unit having a plurality of detection elements arranged in a plane for detecting the X-rays; an image generating unit that generates an image based on the detection result output from the sensor unit; as well as The inspection unit inspects the article based on the image. The plurality of detection elements include: first detection elements arranged in a first row in a direction intersecting the conveying direction; and a second detection element arranged in a second column parallel to the first column, The second detection element is arranged at a position corresponding to a position between two adjacent first detection elements in the first row when viewed in the transport direction.

Images