X-ray inspection device

Abstract

To provide an X-ray inspection device that can suppress the detection omission of a foreign object while keeping the manufacturing cost low.SOLUTION: An X-ray inspection device comprises: a conveyance part that conveys an article in a conveyance direction; an irradiation part that irradiates X-rays onto the article conveyed by the conveyance part; a sensor part that detects X-ray and has multiple detection elements arranged in a plane; an image generation part that generates images based on a detection result output from the sensor part; and an inspection part that performs inspection of the article based on the image. The multiple detection elements include: first detection elements arranged in a first row in a direction perpendicular to the conveyance direction; and second detection elements arranged in a second row parallel to the first row, and the number of second detection elements arranged in the second row is greater than the number of first detection elements arranged in the first row.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Conventionally, inspection devices that utilize electromagnetic waves such as X-rays have been used as devices for inspecting objects (articles) such as foodstuffs, medicines, etc. For example, a nondestructive inspection device described in Patent Document 1 includes an electromagnetic wave irradiating means for irradiating a predetermined electromagnetic wave to an object to be inspected, a conveying means for conveying an object to be inspected placed on a conveying surface in a Y-axis direction, an electromagnetic wave detecting means in which a detecting element group consisting of M detecting elements arranged in the Y-axis direction is arranged in N rows in the X-axis direction, and M×N wirings for electrically connecting each of the M×N detecting elements to a predetermined connection destination located outside one end of the electromagnetic wave detecting means in the Y-axis direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6454820 Summary of the Invention [Problem to be solved by the invention]

[0004] In the non-destructive inspection device described in the above Patent Document 1, a group of detection elements arranged in a lattice pattern is used as an electromagnetic wave detection means. When such an electromagnetic wave detection means is used and a foreign object passes between adjacent detection elements in the X-axis direction, the foreign object may not be detected by all of the detection elements, resulting in a risk of the foreign object being overlooked. In order to prevent such a detection overlook, for example, it is conceivable to increase the integration density of the detection elements in the detection element group. However, simply increasing the integration density of the detection elements would result in an excessive increase in the manufacturing cost of the electromagnetic wave detection means.

[0005] An object of one aspect of the present invention is to provide an X-ray inspection apparatus that can suppress an increase in manufacturing costs and can reduce the risk of overlooking detection of foreign matter. [Means for solving the problem]

[0006] (1) An X-ray inspection device according to one aspect of the present invention includes a conveying unit that conveys an object along a conveying direction, an irradiation unit that irradiates X-rays onto the object conveyed by the conveying unit, a sensor unit that detects X-rays and has a plurality of detection elements arranged in a planar manner, 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 object based on the image, wherein the plurality of detection elements include first detection elements arranged in a first row in a cross direction that intersects the conveying direction and second detection elements arranged in a second row parallel to the first row, and the number of second detection elements arranged in the second row is greater than the number of first detection elements arranged in the first row.

[0007] According to this X-ray inspection device, the multiple detection elements of the sensor unit include first detection elements arranged in a first row in a cross direction crossing the conveying direction and second detection elements arranged in a second row parallel to the first row, and the number of second detection elements arranged in the second row is greater than the number of first detection elements arranged in the first row. Therefore, the second detection elements are smaller than the first detection elements, and foreign objects passing through the sensor unit are more likely to be detected by the multiple second detection elements in the second row. Therefore, it is less likely that detection of foreign objects will be missed. In addition, by including both the first detection elements and the second detection elements in the sensor unit, an increase in the manufacturing cost of the sensor unit is suppressed compared to when the sensor unit has only the second detection elements.

[0008] (2) In the X-ray inspection apparatus described in (1) above, the image may include a first pixel and a second pixel, and the image generating unit may generate the first pixel using a detection result of the first detection element and generate the second pixel using detection results of the second detection elements. In this case, the contrast of the image generated by the image generating unit can be improved.

[0009] (3) In the X-ray inspection apparatus described in (1) above, the image may include a first image including a first pixel generated using the detection result of the first detection element, and a second image including a second pixel generated using the detection results of the second detection elements. In this case, the difference between the brightness, contrast, etc. of the first image and the brightness, contrast, etc. of the second image can be suppressed.

[0010] (4) In the X-ray inspection device described in (2) or (3) above, when two adjacent detection elements among the first detection elements arranged in the first row are the third detection element and the fourth detection element, respectively, some of the second detection elements used to generate the second pixel may be arranged in the transport direction relative to the third detection element, and another part of the second detection elements used to generate the second pixel may be arranged in the transport direction relative to the fourth detection element. In this case, a foreign object that passes between the third detection element and the fourth detection element is likely to be displayed in the second pixel generated using the detection results of the second detection elements. This makes it difficult for a foreign object to go undetected.

[0011] (5) In the X-ray inspection device according to any one of (1) to (4) above, the dimension of the first detection element in the transport direction may be the same as the dimension of the second detection element in the transport direction, and the dimension of the first detection element in the intersecting direction may be a natural number multiple of the dimension of the second detection element in the intersecting direction that is 2 or more. In this case, oversight of detection of a foreign object is effectively prevented.

[0012] (6) In the X-ray inspection device according to any one of (1) to (5) above, the first row and the second row may each be provided in a plurality of rows alternately arranged along the conveying direction. In this case, oversight of detection of foreign matter is effectively prevented.

[0013] (7) An X-ray inspection device according to another aspect of the present invention includes a conveying unit that conveys an object along a conveying direction, an irradiation unit that irradiates X-rays onto the object conveyed by the conveying unit, a sensor unit that detects X-rays and has a plurality of detection elements arranged in a planar manner, 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 object based on the image, wherein the plurality of detection elements include first detection elements arranged in a first row in a cross direction that intersects the conveying direction and second detection elements arranged in a second row parallel to the first row, and the second detection elements are arranged at a position corresponding to between two adjacent first detection elements in the first row when viewed from the conveying direction.

[0014] According to this X-ray inspection device, the multiple detection elements of the sensor unit include first detection elements arranged in a first row in a direction intersecting the transport direction and second detection elements arranged in a second row parallel to the first row, and the second detection elements are arranged at positions corresponding to the gaps between two adjacent first detection elements in the first row as viewed from the transport direction. This allows a foreign object that passes through a gap between adjacent first detection elements to pass over one of the second detection elements without improving the integration density of the sensor unit. This makes it possible to suppress an increase in the manufacturing cost of the sensor unit and to reduce the likelihood of missing a foreign object being detected. Effect of the Invention

[0015] According to one aspect of the present invention, it is possible to provide an X-ray inspection apparatus that can suppress an increase in manufacturing costs and prevent oversight of foreign matter detection. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a configuration diagram of an X-ray inspection apparatus according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing the internal configuration of the shielding box shown in FIG. [Diagram 3] FIG. 3 is a schematic plan view of a main part of the sensor unit. [Figure 4] FIG. 4 is a functional configuration diagram of the control unit. [Diagram 5]FIG. 5(a) is a schematic plan view showing a first example of a combination of a plurality of second detection elements, and FIG. 5(b) is a schematic plan view showing a second example of a combination of a plurality of second detection elements. [Figure 6] FIG. 6 is a schematic plan view of a main part of a sensor unit according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0018] 1, the X-ray inspection apparatus 1 includes an apparatus main body 2, support legs 3, a shielding box 4, a transport 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 generates an X-ray transmission image of an object G while transporting the object G, and inspects the object G based on the X-ray transmission image. The object G before inspection is carried into the X-ray inspection apparatus 1 by a carry-in conveyor 51. The object G after inspection is carried out from the X-ray inspection apparatus 1 by a carry-out conveyor 52.

[0019] 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 leakage of X-rays (electromagnetic waves) to the outside. An inspection room R is provided inside the shielding box 4, where inspection of items G is carried out using X-rays. The shielding box 4 is formed with an entrance 4a and an exit 4b. Items G before inspection are carried into the inspection room R from the carry-in conveyor 51 via the entrance 4a. Items G after inspection are carried out from the inspection room R to the exit conveyor 52 via the exit 4b.

[0020] The conveying unit 5 is a member that conveys the article G, and is disposed so as to penetrate the center of the shielding box 4. The conveying unit 5 conveys the article G along the conveying direction A from the entrance 4a through the inspection room R to the exit 4b. The speed at which the conveying unit 5 conveys the article G (conveying speed) is set by, for example, the control unit 9. The conveying unit 5 is, for example, a belt conveyor stretched between the entrance 4a and the exit 4b. Note that the conveying unit 5 may protrude outward beyond the entrance 4a and the exit 4b.

[0021] As shown in FIG. 1 and FIG. 2, the X-ray irradiation unit 6 is an electromagnetic wave irradiation unit disposed in the shield box 4, and irradiates the object G transported by the transport unit 5 with X-rays. The X-rays include X-rays in various energy ranges from low energy (long wavelength) to high energy (short wavelength). For this reason, the X-ray irradiation unit 6 irradiates the object G transported by the transport unit 5 with X-rays in a plurality of energy ranges. After the X-ray inspection device 1 is started and before the inspection of the object G, the X-ray irradiation unit 6 may irradiate X-rays (i.e., the idling of the X-ray irradiation unit 6). Note that the "low" and "high" in the above-mentioned low energy and high energy indicate relatively "low" and "high" in a plurality of energy ranges irradiated by the X-ray irradiation unit 6, and do not indicate a specific range. In addition, the power (particularly the current) supplied to the X-ray irradiation unit 6 can be changed manually or automatically. By changing the power, the output of the X-rays irradiated to the object G can be changed. This allows the X-rays having an appropriate intensity according to the object G to be irradiated.

[0022] The sensor unit 7 is a sensor unit that detects electromagnetic waves. The sensor unit 7 is disposed in the shielding box 4 at a position facing the X-ray irradiation unit 6 in the vertical direction. The transport unit 5 is disposed between the sensor unit 7 and the X-ray irradiation unit 6 in the vertical direction. FIG. 3 is a schematic plan view of the main part of the sensor unit 7. As shown in FIG. 3, the sensor unit 7 has a plurality of detection elements 10 that detect X-rays and are arranged in a plane (two-dimensionally). The detection elements 10 are arranged at least in a direction (intersecting direction) that intersects with the transport direction A of the transport unit 5.

[0023] In this embodiment, the sensor unit 7 is a direct conversion type detection unit capable of detecting X-rays by a photon counting method. The detection element 10 is, for example, a sensor (multi-energy sensor) that detects X-rays in each of a plurality of energy regions that pass through the article G, and the sensor unit 7 may be a time delay integration sensor (TDI sensor). The detection element 10 includes, for example, a photon detection 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. Photon counting (photon counting) is performed based on the energy (photon energy) obtained at this time. The counting process is performed, for example, by a calculation unit (not shown) included in the sensor unit 7 or the detection element 10. The result (detection result) of the above-mentioned counting process of each detection element 10 by the calculation unit is output to the control unit 9 at a predetermined time interval, for example. The predetermined time is a time (default time) that is predetermined in the X-ray inspection device 1. The above-mentioned predetermined time interval is also called a read interval or a delay time, and can be changed by the control unit 9 as appropriate.

[0024] Each detection element 10 of the sensor unit 7 may discriminate the photon energy of the detected X-ray into two or more energy regions based on an arbitrary threshold. In this case, the sensor unit 7 is capable of photon counting in each energy region. The arbitrary threshold is, for example, one or more values ​​(unit: keV) set by the control unit 9. The arbitrary threshold may be set, for example, by the method described in JP 2023-132587 A, or may be set using the following bright level.

[0025] The multiple detection elements 10 include first detection elements 11 arranged in a first row C1 in the intersecting direction, and second detection elements 12 arranged in a second row C2 parallel to the first row C1. Therefore, the first detection elements 11 are arranged in the first row C1 along the intersecting direction, and the second detection elements 12 are arranged in the second row C2 along the intersecting direction. In the sensor unit 7, the first row C1 and the second row C2 are alternately arranged in multiple rows along the conveying direction A. In other words, in the sensor unit 7, multiple first rows C1 and multiple second rows C2 are set, and the first row C1 and the second row C2 are alternately arranged in the conveying direction A. Therefore, the first detection elements 11 and the second detection elements 12 are alternately arranged in the conveying direction A. Each of the first row C1 and the second row C2 may function as, for example, a pseudo line sensor.

[0026] In this embodiment, the dimension D1 of the first detection element 11 in the conveying direction A is the same as the dimension D2 of the second detection element 12 in the conveying direction A, but is not limited thereto. The dimension D3 of the first detection element 11 in the cross direction is different from the dimension D4 of the second detection element 12 in the cross direction. In this embodiment, the dimension D3 is larger than the dimension D4. For example, the dimension D3 is a natural number multiple of the dimension D4 that is equal to or greater than 2. When the number of the first detection elements 11 in the first row C1 and the number of the second detection elements 12 in the second row C2 are the same, the brightness, contrast, etc. of an image generated using the detection results output from the second row C2 may be significantly different from the image generated using the detection results output from the first row C1. For this reason, in this embodiment, the number of the second detection elements 12 arranged in the second row C2 is greater than the number of the first detection elements 11 arranged in the first row C1. For example, the number of second detection elements 12 arranged in the second column C2 is a natural number multiple of 2 or more of the number of first detection elements 11 arranged in the first column C1. Alternatively, the value obtained by dividing the number of second detection elements 12 arranged in the second column C2 by the number of first detection elements 11 arranged in the first column C1 may be equal to the value obtained by dividing the dimension D3 by the dimension D4.

[0027] The dimension L1 of the gap G1 between the first detection elements 11 in the cross direction may be the same as or different from the dimension L2 of the gap G2 between the second detection elements 12 in the cross direction. In this embodiment, the dimension L1 is larger than the dimension L2. In this case, a part of the second detection element 12 overlaps the gap G1 as viewed from the conveying direction A. For example, a part of two adjacent second detection elements 12 overlap as viewed from the conveying direction A. As a result, even if a foreign object passes only over the gap G1, the foreign object may pass over one or more second detection elements 12. Alternatively, even if the dimensions L1 and L2 are the same, a part of the second detection element 12 may overlap the gap G1 as viewed from the conveying direction A. In other words, regardless of the relationship between the dimensions L1 and L2, the first detection element 11 may overlap multiple second detection elements 12 in the conveying direction A.

[0028] When the X-ray inspection apparatus 1 is started, the sensitivity correction (calibration) of the sensor unit 7 may be performed. In the sensitivity correction, a bright level is acquired based on the X-rays that have not passed through the article G. The bright level is the number of photon counts detected when the X-rays that have not passed through the article G are incident on the sensor unit 7, and corresponds to the intensity of the detection signal included in the detection result. The sensitivity correction of the sensor unit 7 corresponds to the correction of the output difference between the first detection elements 11 and 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 correction, the X-ray irradiation by the X-ray irradiation unit 6 may be started simultaneously with the start of detection of X-rays by the sensor unit 7. The sensitivity correction of the sensor unit 7 is performed, for example, by a method described in Japanese Patent Application No. 2023-39353. In this embodiment, from the viewpoint of improving the contrast of the image generated by the X-ray inspection apparatus 1, it is confirmed whether or not the highest bright level obtained during the sensitivity correction is lower than a predetermined threshold value. That is, it is confirmed whether or not the maximum intensity of the detection signal included in the detection results output from at least a part of the multiple detection elements 10 during the sensitivity correction is lower than a predetermined intensity. The result of the confirmation is output to the control unit 9.

[0029] As shown in FIG. 1, the display operation unit 8 is a member (display unit) provided in the device 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. For example, the operator can set the transport speed of the transport 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 operations accepted by the display operation unit 8 are output to the transport unit 5, the sensor unit 7, the control unit 9, etc.

[0030] The control unit 9 is disposed inside the device body 2. The control unit 9 controls the operation of each part of the X-ray inspection device 1. The control unit 9 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The ROM stores a program for controlling the X-ray inspection device 1, the operation mode of the X-ray inspection device 1, etc.

[0031] 4 is a functional configuration diagram of the control unit 9. As shown in FIG. 4, the control unit 9 includes a receiving unit 21, an image generating unit 22, an inspecting unit 23, a determining unit 24, an output unit 25, and a recording unit 26.

[0032] The receiving unit 21 receives an input operation accepted by the display operation unit 8. The receiving unit 21 receives, for example, the transport speed of the transport unit 5 set via the display operation unit 8. The receiving unit 21 also 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 transmits the received detection results to the image generation unit 22.

[0033] The image generating unit 22 is mainly composed of, for example, a GPU (Graphics Processing Unit), and generates an image based on the detection result output from the sensor unit 7. For example, the image generating unit 22 expands the received signal of the detection result into a two-dimensional image on a memory. The memory in which the two-dimensional image is expanded is, for example, a memory included in the GPU, but is not limited to this. For example, the image generating unit 22 reads out the detection result output from at least a part of the multiple detection elements 10 included in the sensor unit 7 at a predetermined read interval, and generates one or more time delay integration images used for inspecting the item G. For example, multiple transmission images corresponding to each of the multiple energy regions are generated by the image generating unit 22. The image generating unit 22 may also generate one or more difference images from the multiple transmission images.

[0034] The image generating unit 22 may use, for example, an image processing algorithm or a program that is automatically set by machine learning. The image processing algorithm is composed of one image processing filter or a combination of multiple image processing filters. At least one of the multiple image processing algorithms can be automatically generated from multiple image processing filters based on the specifications of the X-ray inspection device 1 or the inspection conditions, etc., by adopting a genetic algorithm (GA = Genetic Algorithms), which is a method that applies the mechanisms of heredity and evolution in the biological world. At least a part of the multiple image processing algorithms can also be appropriately set by an operator via the display operation unit 8. The program that is automatically set by machine learning is a prediction model (trained model) generated by machine learning, and is an inference program in which parameters (trained parameters) obtained as a result of machine learning are incorporated. Examples of machine learning used in the trained model include neural networks, support vector machines, genetic algorithms, etc.

[0035] The image generated by the image generating unit 22 may 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 generating unit 22 generates the first image using the detection result output from each first column C1 of the sensor unit 7, and generates the second image using the detection result output from each second column C2 of the sensor unit 7. One pixel (first pixel) included in the first image is generated, for example, using the detection result of a predetermined first detection element 11 in one or more first columns C1. The predetermined first detection element 11 is a first detection element 11 located at a predetermined position counting from one end of the first column C1 in the cross direction. When the detection element 10 is a TDI sensor, the first pixel is generated using the detection result of a predetermined first detection element 11 in each first column C1. One pixel (second pixel) included in the second image is generated, for example, by using detection results of a plurality of predetermined second detection elements 12 in one or more second columns C2. That is, the second pixel is generated by adding up detection results of two or more second detection elements 12 in one or more second columns C2 and using the result of the addition. When the detection element 10 is a TDI sensor, the second pixel is generated by using the result of adding up detection results of the plurality of second detection elements 12 in each second column C2. The image generation unit 22 may generate a difference image from the first image and the second image.

[0036] The second detection elements used to generate the second pixel may be arranged in order. In the following, an example of a combination of the second detection elements will be described with reference to Figs. 5(a) and 5(b). Fig. 5(a) is a schematic plan view showing a first example of a combination of the second detection elements, and Fig. 5(b) is a schematic plan view showing a second example of a combination of the second detection elements. As shown in Figs. 5(a) and 5(b), two adjacent detection elements among the first detection elements 11 arranged in the first column C1 are respectively designated as the third detection element 11a and the fourth detection element 11b.

[0037] 5(a), 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 aligned with the third detection element 11a in the transport direction A. This makes it difficult for a difference to occur between an image generated using the detection results output from the first row C1 and an image generated using the detection results output from the second row C2.

[0038] 5(b), in the second example, the second pixel is generated using the result of adding up 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 aligned with the third detection element 11a in the conveying direction A, and the other (another part) of the two second detection elements 12 is aligned with the fourth detection element 11b in the conveying direction A. This makes it easier for a foreign object in the article G passing through the gap G1 between the first detection elements 11 in the intersecting direction to be shown by a pixel or image generated using the detection results output from the second row C2.

[0039] In this embodiment, the image generating unit 22 may generate a third image by using all of the detection results output from the sensor unit 7, instead of the first image and the second image, or in addition to the first image and the second image. In this case, the third image includes a first pixel and a second pixel, and the image generating unit 22 generates the first pixel by using the detection result of a predetermined number of first detection elements 11, and generates the second pixel by using the detection results of a predetermined number 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.

[0040] The inspection unit 23 inspects the item G based on the image generated by the image generation unit 22. For example, the inspection unit 23 inspects the item G using the above-mentioned multiple transmission images, the above-mentioned difference image, etc. The inspection unit 23 may inspect the item G based on both the difference image and the transmission image. The inspection unit 23 may inspect the item G based on the transmission image, etc. while the image generation unit 22 is generating the difference image. The inspection unit 23 inspects the item G for, for example, the presence or absence of foreign matter, the presence or absence of cracks, etc., but is not limited to this. In a case where the item G is wrapped in a sheet-like packaging material, the inspection unit 23 may also inspect the packaging material for tears, poor sealing of the packaging material (seal bite), etc. In a case where the item G is contained in a package, the inspection unit 23 may perform a foreign matter confirmation inspection, a missing item confirmation inspection, a storage number confirmation inspection, a hollow confirmation inspection, etc. in the package. The inspection unit 23 transmits the inspection result of the item G to the judgment unit 24 and the recording unit 26.

[0041] The determination unit 24 determines whether or not the item G is a non-defective item based on the inspection results received from the inspection unit 23. For example, the determination unit 24 determines whether or not there is a foreign object in the item G, and whether or not the item G is cracked or chipped. The determination unit 24 transmits the determination result to the output unit 25 and the recording unit 26.

[0042] The output unit 25 outputs the determination result of the determination unit 24 to at least one of parts of the X-ray inspection apparatus 1 other than the control unit 9 and a device different from the X-ray inspection apparatus 1. This allows at least one of the X-ray inspection apparatus 1 and a device different from the X-ray inspection apparatus 1 (for example, a sorting device arranged downstream of the X-ray inspection apparatus 1) to perform an operation when the item G is defective. Other examples of the device different from the X-ray inspection apparatus 1 include, for example, an input conveyor 51, an output conveyor 52, an alarm device, etc.

[0043] The recording unit 26 records signals, data, etc. generated by the control unit 9. For example, the recording unit 26 records the detection result transmitted from the receiving unit 21, the image data transmitted from the image generating unit 22, the data related to the inspection result transmitted from the inspection unit 23, and the data related to the judgment result transmitted from the judgment unit 24.

[0044] According to the X-ray inspection device 1 according to the present embodiment described above, the multiple detection elements 10 of the sensor unit 7 include the first detection elements 11 arranged in the first row C1 in the cross direction and the second detection elements 12 arranged in the second row C2 parallel to the first row C1, and the number of the second detection elements 12 arranged in the second row C2 is greater than the number of the first detection elements 11 arranged in the first row 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 multiple second detection elements 12 in the second row C2. Therefore, the detection of the foreign object is less likely to be missed. In addition, since the sensor unit 7 includes both the first detection elements 11 and the second detection elements 12, the increase in the manufacturing cost of the sensor unit 7 is suppressed compared to the case where the sensor unit 7 has only the second detection elements 12. In other words, the increase in the manufacturing cost of the sensor unit 7 is suppressed compared to the case where only the multiple second rows C2 are set in the sensor unit 7.

[0045] In this embodiment, the image includes a first pixel and a second pixel, and the image generating unit 22 may generate the first pixel using the detection result of the first detection element 11, and generate the second pixel using the detection results of the multiple second detection elements 12. In this case, the contrast of the image generated by the image generating unit 22 can be improved.

[0046] In this embodiment, the image may include a first image including a first pixel generated using the detection result of the first detection element 11, and a second image including a second pixel generated using the detection results of the multiple second detection elements 12. In this case, it is possible to suppress differences in brightness, contrast, etc. between the first image and the second image.

[0047] In this embodiment, some of the second detection elements 12 used to generate the second pixel may be aligned in the transport direction A with respect to the third detection elements 11a, and other parts of the second detection elements 12 used to generate the second pixel may be aligned in the transport direction with respect to the fourth detection elements 11b. In this case, a foreign object that passes between the third detection element 11a and the fourth detection element 11b is likely to be displayed in the second pixel generated using the detection results of the second detection elements 12. This effectively prevents the foreign object from being overlooked.

[0048] In this embodiment, the dimension D1 of the first detection element 11 in the conveying direction A is the same as the dimension D2 of the second detection element 12 in the conveying direction A, and the dimension D3 of the first detection element 11 in the intersecting direction may be a natural number multiple of 2 or more of the dimension D4 of the second detection element 12 in the intersecting direction. In this case, a foreign object passing through the sensor unit 7 is more likely to be detected by the multiple second detection elements 12 in the second row C2, so that it is less likely that a foreign object will go undetected.

[0049] In this embodiment, the first rows C1 and the second rows C2 are each provided in multiple rows alternately along the transport direction A. This effectively prevents foreign matter from going undetected.

[0050] FIG. 6 is a schematic plan view of a main part of a sensor unit according to a modified example. As shown in FIG. 6, the sensor unit 7A is different from the sensor unit 7 of the above embodiment in that it includes a second row C2A instead of the second row C2. In the second row 2CA, a plurality of second detection elements 12A arranged in the intersecting direction are positioned. The dimension D2A of the second detection element 12A in the conveying direction A is the same as the dimension D1 of the first detection element 11, but is not limited to this. Also, the dimension D4A of the second detection element 12A in the intersecting direction is the same as the dimension D3 of the first detection element 11, but is not limited to this. In this modified example, the dimension L2A of the gap G2A between the second detection elements 12A in the intersecting direction is the same as the dimension L1 of the gap G1, but is not limited to this.

[0051] In this modification, the first detection element 11 and the second detection element 12A included in the sensor unit 7 are arranged in a so-called staggered pattern. For example, the second detection element 12A is arranged at a position corresponding to the gap between two adjacent first detection elements 11 in the first row C1 as viewed from the conveying direction A. Similarly, the first detection element 11 is arranged at a position corresponding to the gap between two adjacent second detection elements 12A in the second row C2A as viewed from the conveying direction A. In other words, in the conveying direction A, the gap G1 between the first detection elements 11 overlaps one of the second detection elements 12A, and the gap G2A between the second detection elements 12A overlaps one of the first detection elements 11. Also, as viewed from the conveying direction A, one first detection element 11 in a given first row C1 overlaps two second detection elements 12A in the second row C2 adjacent to the given first row C1. Similarly, when viewed from the transport direction A, one second detection element 12A in a given second row C2 overlaps two first detection elements 11 in the first row C1 adjacent to the given second row C2.

[0052] According to the present modified example described above, even if the integration density of the sensor unit 7A is not improved, a foreign object that passes through the gap G1 between adjacent first detection elements 11 passes over one of the second detection elements 12A. This makes it possible to suppress an increase in the manufacturing cost of the sensor unit 7A and to prevent a foreign object from going undetected.

[0053] Although the embodiment and the modified examples of the present invention have been described above, the present invention is not necessarily limited to the above-mentioned embodiment and modified examples, and various modifications are possible within the scope of the gist of the present invention. For example, in the above-mentioned embodiment, the sensor unit is a device capable of detecting X-rays by a photon counting method, but is not limited to this. The detection element included in the sensor unit may have at least a scintillator and a photodiode.

[0054] In each of the first and second examples of the above embodiment, the second pixel is generated using the sum of the detection results of two second detection elements, but the present invention is not limited to this. For example, the second pixel may be generated using the sum of the detection results of three or more second detection elements. In this case, some of the second detection elements used to generate the second pixel may be aligned with the third detection element in the transport direction, and another part of the second detection elements may be aligned with the fourth detection element in the transport direction. [Explanation of symbols]

[0055] 1...X-ray inspection equipment, 3...support leg, 4...shielding box, 4a...feed-in entrance, 4b...feed-out exit, 5...transport section, 6...X-ray irradiation section, 7...sensor section, 8...display operation section, 9...control section, 10...detection element, 11...first detection element, 11a...third detection element, 11b...fourth detection element, 12...second detection element, 21...receiving section, 22...image generation section, 23...inspection section, 24...judgment section, 25...output section, 26...recording section, A...transport direction, G...item.

Claims

1. A conveying unit that conveys the article along a conveying direction; an irradiation unit that irradiates the object transported by the transport unit with X-rays; a sensor unit having a plurality of detection elements arranged in a plane and capable of detecting the X-rays; an image generating unit that generates an image based on a detection result output from the sensor unit; an inspection unit that inspects the item based on the image; Equipped with the plurality of detection elements include first detection elements arranged in a first row in a cross direction crossing the transport 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 is greater than the number of the first detection elements arranged in the first row. X-ray inspection equipment.

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

3. 2. The X-ray inspection device of claim 1, wherein the image includes a first image including a first pixel generated using the detection result of the first detection element, and a second image including a second pixel generated using the detection results of a plurality of the second detection elements.

4. When two adjacent detection elements among the first detection elements arranged in the first row are a third detection element and a fourth detection element, a part of the second detection elements used to generate the second pixels is aligned in the transport direction with respect to the third detection elements, The X-ray inspection apparatus according to claim 2 , wherein another part of the plurality of second detection elements used to generate the second pixels is aligned in the transport direction with respect to the fourth detection elements.

5. a dimension of the first detection element in the transport direction is the same as a dimension of the second detection element in the transport direction; 4. The X-ray inspection apparatus according to claim 1, wherein a dimension of the first detection element in the intersecting direction is a natural number multiple of 2 or more of a dimension of the second detection element in the intersecting direction.

6. The X-ray inspection apparatus according to claim 1 , wherein the first rows and the second rows are each provided in a plurality of rows alternately arranged along the transport direction.

7. A conveying unit that conveys the article along a conveying direction; an irradiation unit that irradiates the object transported by the transport unit with X-rays; a sensor unit having a plurality of detection elements arranged in a plane and capable of detecting the X-rays; an image generating unit that generates an image based on a detection result output from the sensor unit; an inspection unit that inspects the item based on the image; Equipped with the plurality of detection elements include first detection elements arranged in a first row in a cross direction crossing the transport direction, and second detection elements arranged in a second row parallel to the first row, the second detection element is disposed at a position corresponding to a gap between two adjacent first detection elements in the first row as viewed from the transport direction. X-ray inspection equipment.

Images