X-ray inspection device

Abstract

This X-ray inspection device is provided with: a transport unit that transports an article; an irradiation unit that irradiates X-rays on the article conveyed by the conveyance unit; a sensor unit in which a plurality of detection elements for detecting X-rays are arranged in a planar shape; an image generation unit that reads out detection results output from at least some of the plurality of detection elements and generates an image; and a mode switching unit that switches between a first mode in which the first power is supplied to the irradiation unit and a second mode in which the second power smaller than the first power is supplied to the irradiation unit, and that changes the reading frequency of the detection result by the image generation unit when the mode switching unit switches from the first mode to the second mode.

Description

Technical Field

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

[0002] In the past, inspection devices using electromagnetic waves such as X-rays were used as devices for inspecting objects (articles) such as food and medicines. For example, the article inspection device described in Japanese Patent Publication No. 2021-156635 includes an irradiation unit and a detection unit, the irradiation unit irradiates electromagnetic waves that spread radially toward the moving object to be inspected, and the detection unit detects the electromagnetic waves affected by the object to be inspected through a plurality of detection elements.

[0003] However, in the above-mentioned article inspection device, there is a tendency that the irradiation unit, which is the output source of the electromagnetic wave, is the first to deteriorate. In order to suppress the degradation of the irradiation unit, it is considered to suppress the output of the electromagnetic wave. However, when only the output of the electromagnetic wave is suppressed, the detection unit of the electromagnetic wave becomes insufficient, and there is a concern that the quality of the inspected object cannot be determined with high accuracy. Summary of the invention

[0004] An object of one aspect of the present invention is to provide an X-ray inspection apparatus capable of performing a good inspection even when the output of X-rays is suppressed.

[0005] (1) An X-ray inspection device according to one aspect of the present invention comprises: a conveying unit for conveying an article; an irradiating unit for irradiating the article conveyed by the conveying unit with X-rays; a sensor unit in which a plurality of detection elements for detecting X-rays are arranged in a planar shape; an image generating unit for reading out detection results output from at least a portion of the plurality of detection elements and generating an image; and a mode switching unit for switching between a first mode in which a first power is supplied to the irradiating unit and a second mode in which a second power smaller than the first power is supplied to the irradiating unit, wherein the mode switching unit changes a frequency at which the image generating unit reads out the detection results when switching from the first mode to the second mode.

[0006] According to the X-ray inspection device, the mode switching unit changes the readout frequency of the detection result by the image generation unit when switching from a first mode in which a first power is supplied to the irradiation unit to a second mode in which a second power smaller than the first power is supplied to the irradiation unit. For example, by reducing the readout frequency of the detection result when switching from the first mode to the second mode, the exposure time of a plurality of detection elements within a prescribed period can be extended. Thus, even when the output of the X-ray irradiated from the irradiation unit is weakened in the second mode, a good X-ray detection result can be output from each detection element. Therefore, by using the above-mentioned X-ray inspection device, a good inspection can be performed even if the output of the X-ray is suppressed.

[0007] (2) In the X-ray inspection device described in (1) above, the sensor unit may detect X-rays by photon counting. In this case, the contrast of the image generated by the image generating unit can be improved.

[0008] (3) In the X-ray inspection apparatus described in (1) or (2) above, the second power may be an arbitrary multiple of the first power that is less than 1. In this case, power consumption of the X-ray inspection apparatus can be reduced satisfactorily.

[0009] (4) In the X-ray inspection apparatus described in (3) above, when switching from the first mode to the second mode, the mode switching unit may multiply the readout frequency by an arbitrary multiple smaller than 1. In this case, each sensor can reliably output a good X-ray detection result.

[0010] (5) In the X-ray inspection device described in any one of (1) to (4), when switching from the first mode to the second mode, the sensor unit may change the number of detection elements that are in operation. In this case, it is less likely that there will be detection elements with insufficient exposure time, and thus it is less likely that an unclear image will be generated.

[0011] (6) In the X-ray inspection device described in (5) above, when switching from the first mode to the second mode, the change ratio of the readout frequency may be the same as the ratio of the detection elements in operation among the plurality of detection elements. In this case, good X-ray detection results can be reliably output from the detection elements in operation.

[0012] (7) The X-ray inspection apparatus described in any one of (1) to (6) above may further include a determination unit that determines whether or not a foreign object is present in an object including food based on an image. In this case, the determination unit can satisfactorily determine whether or not a foreign object is present even if the output of X-rays is suppressed.

[0013] Effects of the Invention

[0014] According to one aspect of the present invention, it is possible to provide an X-ray inspection apparatus capable of performing good inspection even when the output of X-rays is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing the configuration of an X-ray inspection apparatus according to one embodiment.

[0016] Figure 2 yes Figure 1 The schematic diagram of the internal structure of the shielding box is shown.

[0017] Figure 3 Schematic diagram showing detection elements in operation and detection elements not used for image generation.

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

[0019] Description of Reference Numerals

[0020] 1: X-ray inspection device, 3: supporting legs, 4: shielding box, 4a: input port, 4b: output port, 5: conveying unit, 6: X-ray irradiation unit, 7: sensor unit, 8: display operation unit, 10: control unit, 11: detection element, 21: receiving unit, 22: mode switching unit, 23: image generating unit, 24: inspection unit, 25: determination unit, 26: output unit, 27: recording unit, A: conveying direction, G: object. DETAILED DESCRIPTION

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0022] like Figure 1 As shown, the X-ray inspection device 1 includes a device body 2, a support leg 3, a shield box 4, a conveyor 5, an X-ray irradiation unit 6, a sensor unit 7, a display operation unit 8, and a control unit 10. The X-ray inspection device 1 generates an X-ray transmission image of the article G while conveying the article G, and inspects the article G based on the X-ray transmission image. The article G before inspection is input into the X-ray inspection device 1 by an input conveyor 51. The inspected article G is output from the X-ray inspection device 1 by an output conveyor 52.

[0023] The device body 2 accommodates the control unit 10 and the like. The support legs 3 support the device body 2. The shielding box 4 is provided on the device body 2. The shielding box 4 is a shell that prevents X-rays (electromagnetic waves) from leaking to the outside. An inspection room R for inspecting the article G using X-rays is provided inside the shielding box 4. An input port 4a and an output port 4b are formed on the shielding box 4. The article G before inspection is input into the inspection room R from the input conveyor 51 via the input port 4a. The article G after inspection is output from the inspection room R to the output conveyor 52 via the output port 4b.

[0024] The conveying unit 5 is a component for conveying the article G, and is arranged in a manner that passes through the center of the shielding box 4. The conveying unit 5 conveys the article G from the input port 4a to the output port 4b via the inspection room 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, for example, the control unit 10. The conveying unit 5 is, for example, a belt conveyor installed between the input port 4a and the output port 4b. It should be noted that the conveying unit 5 may also protrude further outward than the input port 4a and the output port 4b.

[0025] like Figure 1 and Figure 2As shown, the X-ray irradiation unit 6 is an electromagnetic wave irradiation unit arranged in the shielding box 4, and irradiates X-rays to the object G transported by the conveying unit 5. The X-rays include X-rays in various energy ranges from low energy (long wavelength) to high energy (short wavelength). To this end, the X-ray irradiation unit 6 irradiates the object G transported by the conveying unit 5 with X-rays in multiple energy ranges. It is also possible to implement X-ray irradiation by the X-ray irradiation unit 6 after the X-ray inspection device 1 is started and before the object G is inspected (that is, the X-ray irradiation unit 6 is idle). It should be noted that the "low" and "high" in the above-mentioned low energy and high energy represent relatively "low" and "high" in the multiple energy ranges irradiated from the X-ray irradiation unit 6, and do not represent a specific range.

[0026] In the present embodiment, 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 article G can be changed. For example, when an excessive amount of X-rays is irradiated to the sensor unit 7, the power supplied to the X-ray irradiation unit 6 is reduced. On the other hand, when an insufficient amount of X-rays is irradiated to the sensor unit 7, the power supplied to the X-ray irradiation unit 6 is increased. The power (particularly the current) supplied to the X-ray irradiation unit 6 may be switched when the operation mode of the X-ray inspection device 1 is set manually or automatically. For example, when the operation mode includes a normal mode (first mode) and a power saving mode (second mode), a first power is supplied to the X-ray irradiation unit 6 in the normal mode, and a second power smaller than the first power is supplied to the X-ray irradiation unit 6 in the power saving mode. The second power is, for example, a reciprocal multiple of a natural number of the first power, but is not limited thereto. For example, the second power may be any multiple (0.9 times, 0.85 times, 0.6 times, or 0.3 times, etc.) of the first power that is less than 1 times. Note that in the power saving mode, the inspection of the article G is performed in a state where the power supplied to the X-ray inspection apparatus 1 is reduced compared to the normal mode. Note that a natural number in this specification is an integer greater than 2.

[0027] The sensor unit 7 is a sensor unit that detects electromagnetic waves. The sensor unit 7 is arranged in a position opposite to the X-ray irradiation unit 6 in the up-down direction in the shielding box 4. The sensor unit 7 has a plurality of detection elements 11 arranged in a planar shape (two-dimensional). The detection elements 11 are arranged at least in a direction (width direction) orthogonal to the conveying direction A and the up-down direction of the conveying unit 5. A line sensor may also be formed by a part of the plurality of detection elements 11 in the sensor unit 7. For example, in the sensor unit 7, a plurality of line sensors extending along the above-mentioned width direction may be arranged in the conveying direction A. In this case, each of the plurality of line sensors includes a plurality of detection elements 11 arranged along the above-mentioned width direction. It should be noted that, unless otherwise specifically mentioned below, the plurality of detection elements 11 are equivalent to all the detection elements 11 included in the sensor unit 7.

[0028] In the present embodiment, the sensor unit 7 is a direct conversion type detection unit capable of detecting X-rays by photon counting. In addition, the detection element 11 is, for example, a sensor (multi-energy sensor) that detects X-rays in multiple energy ranges passing through the article G, and the sensor unit 7 may also be a time delay integration sensor (TDI sensor: Time Delay Integration sensor). The detection element 11 includes, for example, a photon detection sensor such as a CdTe semiconductor detector. In the detection element 11, for example, electron-hole pairs are generated by the arrival of X-ray photons. Based on the energy (photon energy) obtained at this time, a photon counting process (photon counting) is performed. The counting process is implemented, for example, by a calculation unit (not shown) included in the sensor unit 7 or the detection element 11. The result of the above-mentioned counting process (detection result) of each detection element 11 implemented by the calculation unit is output to the control unit 10, for example, at a predetermined time interval. It should be noted that the predetermined time interval is also called a readout interval or a delay time, and can be appropriately changed by the control unit 10 (details will be described later).

[0029] Each detection element 11 of the sensor unit 7 can also distinguish the photon energy of the detected X-ray into two or more energy ranges based on an arbitrary threshold value. In this case, the sensor unit 7 can count the photons in each energy range. The arbitrary threshold value is, for example, one or more values ​​(unit: keV) set by the control unit 10. The arbitrary threshold value can be set, for example, according to the method described in Japanese Patent Laid-Open No. 2023-132587, or can be set using the following brightness level.

[0030] The sensor unit 7 may change the number of detection elements 11 to be operated according to the transport speed of the transport unit 5 , the operation mode of the X-ray inspection apparatus 1 , and the like. Figure 3 Schematic diagram showing detection elements in operation and detection elements not used for image generation. Figure 3 , a part of the detection elements 11 included in the sensor unit 7 is shown, and the detection elements 11 in operation (the detection elements 11 used to generate images) are marked with "○", and the detection elements 11 not used to generate images are marked with "×". For example, when the above-mentioned conveying speed is too high to output good detection results from all the detection elements 11, when the control unit 10 switches the operation mode of the X-ray inspection device 1 from the above-mentioned normal mode to the above-mentioned labor-saving mode, etc. Figure 3As shown, the sensor unit 7 limits the number of detection elements 11 in operation. Thus, good detection results can be output from all the detection elements 11 in operation. The detection elements 11 to be limited are selected according to a predetermined rule, pattern, etc. The rule, pattern, etc. can also be appropriately changed according to the type of the article G, the accumulated operation time of the X-ray inspection device 1, etc. For example, when the X-ray inspection device 1 operates in the second mode, the detection elements 11 in operation can be always the same, or can be changed according to the accumulated operation time of the X-ray inspection device 1, etc. On the other hand, when the sensor unit 7 limits the number of detection elements 11 in operation and the above-mentioned conveying speed is no longer too high, the sensor unit 7 releases the limit on the number of detection elements 11 in operation. Thus, the number of detection elements 11 in operation increases. It should be noted that when the above-mentioned plurality of line sensors are arranged in the sensor unit 7, the sensor unit 7 can also limit the number of line sensors in operation. In this case, the control of the detection elements 11 by the sensor unit 7 can be simplified. For example, when the X-ray inspection device 1 operates in the second mode, the multiple line sensors included in the sensor unit 7 may skip one or two of the multiple line sensors in the conveying direction A. It should be noted that in this embodiment, the sensor unit 7 changes the number of detection elements 11 in operation, but is not limited to this. The number of detection elements 11 in operation may also be changed manually, for example.

[0031] When the X-ray inspection device 1 is started, the sensitivity correction (calibration) of the sensor unit 7 can be implemented. In this sensitivity correction, the brightness level of each detection element 11 is acquired based on the X-ray that has not passed through the object G. The brightness level is the number of photon counts detected when the X-ray that has not passed through the object G enters the sensor unit 7. The sensitivity correction of the sensor unit 7 is equivalent to the correction of the output difference between the detection elements 11 included in the sensor unit 7. From the perspective of shortening the startup time of the X-ray inspection device 1, in the above-mentioned sensitivity correction, the X-ray irradiation unit 6 can also start irradiating X-rays at the same time as the sensor unit 7 starts detecting X-rays. It should be noted that the sensitivity correction of the sensor unit 7 is implemented, for example, according to the method described in Japanese Patent Application No. 2023-39353.

[0032] like Figure 1As shown, the display operation unit 8 is a component (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 operation mode of the X-ray inspection device 1, the conveying speed of the conveying unit 5, the power (at least one of the current and the voltage) supplied to the X-ray irradiation unit 6, the number of detection elements 11 that perform the operation, etc. via the display operation unit 8. The input operation accepted by the display operation unit 8 is output to the conveying unit 5, the sensor unit 7, the control unit 10, etc.

[0033] The control unit 10 is arranged inside the apparatus body 2. The control unit 10 controls the operation of each part of the X-ray inspection apparatus 1. The control unit 10 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 apparatus 1, an operation mode of the X-ray inspection apparatus 1, etc.

[0034] Figure 4 This is the functional structure diagram of the control unit. Figure 4 As shown, the control unit 10 includes a receiving unit 21 , a mode switching unit 22 , an image generating unit 23 , an inspecting unit 24 , a determining unit 25 , an output unit 26 , and a recording unit 27 .

[0035] The receiving unit 21 receives an input operation received by the display operation unit 8. The receiving unit 21 sends a signal (mode designation signal) designating the operation mode of the X-ray inspection apparatus 1 set via the display operation unit 8 to the mode switching unit 22 and the output unit 26. The mode designation signal sent to the output unit 26 is output to the sensor unit 7. In addition, the receiving unit 21 receives the detection result output from the sensor unit 7. The receiving unit 21 sends the received detection result to the image generating unit 23.

[0036] The mode switching unit 22 switches to the operation mode of the X-ray inspection device 1 corresponding to the above-mentioned mode designation signal. For example, the mode switching unit 22 switches the above-mentioned normal mode in which the above-mentioned first power is supplied to the X-ray irradiation unit 6 and the above-mentioned power saving mode in which the above-mentioned second power is supplied to the X-ray irradiation unit 6. For example, when the mode switching unit 22 switches from the normal mode to the power saving mode, the image generation unit 23 changes the reading frequency (unit: times / time) of the detection result. The reading frequency is equivalent to the inverse of the above-mentioned reading interval. Therefore, in the present embodiment, when the mode switching unit 22 switches from the normal mode to the power saving mode, the image generation unit 23 changes the above-mentioned reading interval of the detection result.

[0037] In the present embodiment, when the mode switching unit 22 switches from the normal mode to the power saving mode, not only the power supplied to the X-ray irradiation unit 6 is reduced, but also the mode switching unit 22 reduces the frequency of the readout of the detection result by the image generating unit 23. Thus, the period during which the detection element 11 is exposed to X-rays (X-ray exposure period) can be extended in the above-mentioned readout interval. The mode switching unit 22 may also change the frequency of the readout of the detection result by the image generating unit 23 when switching from the power saving mode to the normal mode. Thus, it is not easy for the detection element 11 to detect excessive X-rays. In the present embodiment, when the mode switching unit 22 switches from the normal mode to the power saving mode, the readout frequency is multiplied by the reciprocal of a natural number, but it is not limited thereto. For example, when the mode switching unit 22 switches from the normal mode to the power saving mode, the readout frequency may be multiplied by any multiple less than 1 (0.75 times, 0.7 times, 0.6 times or 0.4 times, etc.). In other words, when the mode switching unit 22 switches from the normal mode to the power saving mode, the readout interval may be multiplied by a natural number or by any multiple greater than 1 (1.25 times, 1.4 times, 1.6 times, or 1.75 times, etc.). Regardless of the change in the readout interval, the period required for the calculation unit included in the sensor unit 7 or the detection element 11 to perform the counting process is constant. Therefore, regardless of the operation mode of the X-ray inspection device 1, it is sufficient to change the readout interval so that the ratio of the X-ray exposure period of each detection element 11 in the readout interval is greater than the specified value.

[0038] When the mode switching unit 22 switches from the normal mode to the power saving mode, both the above-mentioned change in the readout frequency and the change in the number of detection elements 11 in operation by the sensor unit 7 may be implemented. In this case, the change ratio of the readout frequency may also have a certain correlation with the ratio of the detection elements 11 in operation among all the detection elements 11 included in the sensor unit 7. For example, the change ratio of the readout interval may be the reciprocal multiple of the ratio of the detection elements 11 in operation among the plurality of detection elements 11, or may be a ratio other than the reciprocal multiple of the ratio. When the change ratio of the readout frequency is the same as the ratio of the detection elements 11 in operation among the plurality of detection elements 11, the operation control of the X-ray inspection device 1 can be facilitated.

[0039] The image generation unit 23 is mainly composed of a GPU (Graphics Processing Unit), for example, and expands the detection result signal 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 23 reads the detection result output from at least a part of the multiple detection elements 11 included in the sensor unit 7 at the above-mentioned readout interval, and generates one or more time-delayed integrated images for inspecting the object G. For example, the image generation unit 23 generates a plurality of transmission images corresponding to each of the above-mentioned multiple energy ranges. In addition, the image generation unit 23 can also generate one or more differential images based on the multiple transmission images. The image generation unit 23 can use an image processing algorithm, for example, or a program 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 or more of the multiple image processing algorithms can be automatically generated from multiple image processing filters based on the specifications or inspection conditions of the X-ray inspection device 1 using a genetic algorithm (GA=Genetic Algorithms), wherein the genetic algorithm is a method that applies the mechanism of inheritance and evolution in the biological world. At least a part of the plurality of image processing algorithms can also be appropriately set by the 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 in which parameters (learned parameters) obtained as a result of machine learning are embedded. Examples of machine learning for the learned model include neural networks, support vector machines, genetic algorithms, and the like.

[0040] The inspection unit 24 inspects the article G based on the image generated by the image generating unit 23. For example, the inspection unit 24 inspects the article G using the above-mentioned multiple transmission images, the above-mentioned differential image, etc. The inspection unit 24 may inspect the article G based on both the differential image and the transmission image. The inspection unit 24 may inspect the article G based on the transmission image, etc., while the differential image is generated by the image generating unit 23. The inspection unit 24 inspects the article G for, for example, foreign matter, cracks, and defects, but is not limited thereto. When the article G is wrapped in a sheet-like packaging material, the inspection unit 24 may also inspect the damage of the packaging material, poor sealing of the packaging material (seal bite), etc. When the article G is stored in a packaging body, the inspection unit 24 may perform foreign matter confirmation inspection, missing product confirmation inspection, storage number confirmation inspection, cavity confirmation inspection, etc. in the packaging body. The inspection unit 24 sends the inspection result of the article G to the determination unit 25 and the recording unit 27.

[0041] The determination unit 25 determines whether the article G is a qualified article based on the inspection result received from the inspection unit 24. For example, the determination unit 25 determines whether there is foreign matter in the article G, whether the article G has cracks or defects, etc. The determination unit 25 sends the determination result to the output unit 26 and the recording unit 27.

[0042] The output unit 26 outputs the determination result of the determination unit 25 to at least one of a portion other than the control unit 10 in the X-ray inspection apparatus 1 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 at a position downstream of the X-ray inspection apparatus 1) can perform an action when the article G is a defective product. As another example of the above-mentioned device different from the X-ray inspection apparatus 1, for example, the input conveyor 51, the output conveyor 52, the notification device, etc. can be cited.

[0043] The recording unit 27 records signals, data, and the like generated by the control unit 10. For example, the recording unit 27 records the detection result sent from the receiving unit 21, the image data sent from the image generating unit 23, the data related to the inspection result sent from the inspection unit 24, and the data related to the determination result sent from the determination unit 25.

[0044] According to the X-ray inspection device 1 according to the present embodiment described above, the mode switching unit 22 changes the frequency of reading the detection result by the image generation unit 23 when switching from the normal mode in which the first power is supplied to the X-ray irradiation unit 6 to the power saving mode in which the second power is supplied to the X-ray irradiation unit 6. For example, by reducing the frequency of reading the detection result when switching from the normal mode to the power saving mode, the period during which each detection element 11 is exposed to X-rays (X-ray exposure period) can be extended in the above-mentioned readout interval. Thus, even when the output of X-rays irradiated from the X-ray irradiation unit 6 is weakened in the power saving mode, good X-ray detection results can be output from each detection element 11 in the above-mentioned readout interval. Therefore, by using the X-ray inspection device 1 according to the present embodiment, good inspection can be performed even if the output of X-rays is suppressed.

[0045] In the present embodiment, the sensor unit 7 may detect X-rays by photon counting. In this case, the contrast of the image generated by the image generating unit 23 can be improved.

[0046] In the present embodiment, the second power may be a natural number reciprocal multiple of the first power. In this case, the power consumption of the X-ray inspection apparatus 1 can be reduced satisfactorily.

[0047] In the present embodiment, the mode switching unit 22 may multiply the readout frequency by the reciprocal of a natural number when switching from the normal mode to the power saving mode. In this case, each detection element 11 can reliably output a good X-ray detection result.

[0048] In this embodiment, when switching from the normal mode to the power saving mode, the sensor unit 7 may change the number of operating detection elements 11. In this case, detection elements 11 with insufficient X-ray exposure period are less likely to exist, so unclear images are less likely to be generated.

[0049] In this embodiment, when switching from the normal mode to the power saving mode, the change ratio of the readout frequency may be the same as the ratio of the operating detection elements 11 among the plurality of detection elements 11. In this case, each operating detection element 11 can reliably output a good X-ray detection result.

[0050] The X-ray inspection apparatus 1 according to the present embodiment includes a determination unit 25 that determines the presence or absence of foreign matter in an article G including food based on an image. Therefore, even if the output of X-rays is suppressed, the determination unit 25 can satisfactorily determine the presence or absence of foreign matter.

[0051] The embodiments of the present invention have been described above, but the present invention is not necessarily limited to the above embodiments, and various changes can be made within the scope of the main purpose. For example, in the above embodiments, the sensor unit is a device that can detect X-rays by photon counting, but it is not limited to this. The detection element included in the sensor unit may also have at least a scintillator and a photodiode.

[0052] In the above-mentioned embodiment, the operation mode of the X-ray inspection device includes a normal mode and a power saving mode, but is not limited thereto. For example, the operation mode may also include a plurality of normal modes. In each of the plurality of normal modes, for example, the power supplied to the X-ray irradiation unit is different from each other. In addition, the above-mentioned operation mode may also include a plurality of power saving modes. In each of the plurality of power saving modes, for example, at least one of the power supplied to the X-ray irradiation unit and the ratio of the detection elements to be operated is different from each other.

Claims

1. An X-ray inspection device comprising: Conveying department, conveying items; an irradiation unit for irradiating the article conveyed by the conveying unit with X-rays; a sensor section in which a plurality of detection elements for detecting the X-rays are arranged in a planar shape; an image generating unit that reads out detection results output from at least a part of the plurality of detection elements and generates an image; as well as a mode switching unit for switching between a first mode in which a first power is supplied to the irradiation unit and a second mode in which a second power is supplied to the irradiation unit, the second power being smaller than the first power, The mode switching unit changes a frequency at which the image generating unit reads out the detection result when switching from the first mode to the second mode.

2. The X-ray inspection apparatus according to claim 1, wherein: The sensor unit detects the X-rays by photon counting.

3. The X-ray inspection device according to claim 1 or 2, wherein: The second power is any multiple smaller than 1 times of the first power.

4. The X-ray inspection apparatus according to claim 3, wherein: The mode switching unit multiplies the readout frequency by the arbitrary multiple smaller than 1 when switching from the first mode to the second mode.

5. The X-ray inspection apparatus according to claim 1 or 2, wherein: When switching from the first mode to the second mode, the sensor unit changes the number of the detection elements that operate.

6. The X-ray inspection apparatus according to claim 5, wherein: When switching from the first mode to the second mode, the change ratio of the readout frequency is the same as the ratio of the detection elements operating among the plurality of detection elements.

7. The X-ray inspection apparatus according to claim 1 or 2, wherein: The X-ray inspection apparatus further includes a determination unit configured to determine whether or not a foreign object is present in the article including food based on the image.

Images