X-ray inspection equipment and X-ray inspection system

Abstract

To provide an X-ray inspection device and X-ray inspection system that can reliably detect various types of deterioration and abnormalities in openings with shielding curtains using a simple configuration, thereby enhancing safety. [Solution] An X-ray inspection apparatus comprising an X-ray imaging unit 20 that images an object to be inspected PF with X-rays within a housing 25, an image processing unit 33 that inspects the object to be inspected PF based on the X-ray image Dpx from the X-ray imaging unit 20, and a shielding curtain 27 for openings 25c and 25e, further comprising: an aperture imaging unit 51, 52 that images predetermined imaging areas R1, R2 during the shielding period of the openings 25c and 25e and outputs them as aperture images Dg1, Dg2; an image feature recognition unit 54, 55 that recognizes morphological features relating to the shielding state of the openings 25c and 25e that appear in the aperture images Dg1, Dg2 as predetermined image feature quantities fr1, fr2; and a safety determination unit 56 that determines the safety relating to the shielding function of the openings 25c and 25e based on the image feature quantities fr1, fr2.

Description

Technical Field

[0001] The present invention relates to an X-ray inspection apparatus and an X-ray inspection system, and particularly to an X-ray inspection apparatus and an X-ray inspection system for inspecting the quality state of an object to be inspected based on an X-ray inspection image of the object to be inspected obtained by X-ray imaging the object to be inspected.

Background Art

[0002] Conventionally, based on an X-ray inspection image obtained by X-ray imaging an object to be inspected during conveyance, an X-ray inspection apparatus and an X-ray inspection system are known which detect a defective state of the object to be inspected, such as foreign matter contamination, missing products, or defective sealing of a packaging package, or perform volume measurement or relative mass measurement.

[0003] In such an X-ray inspection apparatus or X-ray inspection system, generally, the housing of the X-ray inspection apparatus has an X-ray shielding structure for X-ray imaging the object to be inspected inside, and at the loading entrance and unloading exit of the article, shielding curtains containing X-ray shielding metals (lead, stainless steel, etc.) are provided in a curtain shape with a predetermined number of slits having a plurality of strip-shaped widths. Further, since the loading entrance and unloading exit of the article have a structure that allows a person's hand to enter, various measures are taken to prevent X-ray exposure that affects the operator.

[0004] As a conventional X-ray inspection apparatus or X-ray inspection system of this type, for example, a light emitting and receiving element for detecting the passage of an object to be inspected within a predetermined monitoring area set inside the loading entrance and unloading exit of the article is provided, and whether the object has passed through the monitoring area or a human body has passed through is determined based on whether the change in the detection signal level of the light emitting and receiving element corresponds to a preset article passage time (light shielding time). When it is determined that a human body has passed through, the X-ray output is limited to less than a predetermined amount to prevent X-ray exposure in advance, and an alarm output is performed (see, for example, Patent Document 1).

[0005] Furthermore, there is a shielding curtain unit that comprises a base that can be attached to and detached above a conveyor from a housing having an entrance and exit for articles and an opening and closing door on the front, and a plurality of shielding curtains on the entrance and exit sides attached to the base. When this unit is attached to the housing, a shutter operating device provided on the unit moves the shutter plate on the housing side to expose an operating switch that was hidden inside, and when the opening and closing door is closed, an operating piece on the upper end of the opening and closing door operates the operating switch, enabling the X-ray inspection device to be operated (see, for example, Patent Document 2).

[0006] Furthermore, it is known that infrared sensors for object detection are installed above the entrance and exit to detect temperature changes within the monitoring area. Based on the fact that the temperature change pattern detected by these sensors differs between when X-ray inspection is performed on only the object to be inspected while it is being transported at a specified transport speed and when a human body is detected instead of the object to be inspected, it is possible to determine whether or not a human body has entered the monitoring area. When a human body is detected by the infrared sensor, the X-ray output of the X-ray generator is reduced (see, for example, Patent Document 3). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-311699 [Patent Document 2] Japanese Patent Publication No. 2003-279500 [Patent Document 3] Japanese Patent Publication No. 2018-165634 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, while the conventional X-ray inspection devices and systems described above can detect when a person's hand or other object approaches or is inserted into the loading / unloading area of ​​an item immediately before X-ray inspection, they cannot reliably detect a decrease in safety due to the deterioration of shielding curtains such as lead rubber curtains. Therefore, they are insufficient to adequately enhance the safety of X-ray inspection devices.

[0009] Specifically, even when the shielding curtain is positioned in a manner suitable for suppressing X-ray leakage according to the shape and properties of the object being inspected, the diverse shapes and transport methods of the objects being inspected can lead to various forms of deterioration of the shielding curtain, such as creating gaps that are difficult to measure due to various warping, or causing discoloration due to irregular fraying or wear marks on the transport belt, which can raise concerns about reduced safety.

[0010] Furthermore, while it is possible to detect the breakage or detachment of strip-shaped portions of a shielding curtain, such as a lead rubber curtain, there is a problem in that it is not possible to reliably detect gaps in multiple directions or at multiple points between adjacent strip-shaped portions, or the various gaps between the shielding curtain and the conveyor belt. This also leads to the problem that the device configuration becomes complex and costly in order to detect various abnormalities.

[0011] Therefore, the present invention aims to provide an X-ray inspection apparatus and an X-ray inspection system that can reliably detect various deteriorations and abnormalities in openings with shielding curtains with a simple configuration, thereby significantly enhancing safety. [Means for solving the problem]

[0012] To achieve the above objective, the X-ray inspection apparatus according to the present invention comprises: (1) a housing having at least one opening through which an object to be inspected conveyed in a predetermined direction by a conveyor passes; an X-ray imaging unit that images the object to be inspected with X-rays within the housing; an image processing unit that inspects the quality of the object to be inspected based on the X-ray image from the X-ray imaging unit; and a shielding curtain disposed in the opening, further comprising: an opening imaging unit that images a predetermined imaging area including the opening and outputs it as an opening image when at least the object to be inspected does not pass through the opening; an image feature recognition unit that recognizes classifiable morphological features relating to the shielding state of the opening that appear in the opening image from the opening imaging unit as predetermined image feature quantities; and a safety determination unit that determines the safety of the shielding function of the opening by the shielding curtain based on the predetermined image feature quantities recognized by the image feature recognition unit.

[0013] With this configuration, when the object under inspection does not pass through the opening, the opening imaging unit captures a predetermined imaging area including the opening and outputs it as an opening image. When the image feature recognition unit recognizes classifiable morphological features related to the shielding state of the opening that appear in the opening image as predetermined image feature quantities, the safety determination unit accurately determines the safety of the shielding function of the opening by the shielding curtain based on these image feature quantities. As a result, this X-ray inspection device can reliably detect various deteriorations and abnormalities in openings with shielding curtains with a simple configuration, thereby significantly enhancing safety. Here, "when the object under inspection does not pass through the opening" refers to a non-inspection period when inspection of the object under inspection is stopped, or a shielding period during which a stable shielding state of the shielding curtain is achieved when the transport interval of the object under inspection is large enough to allow a stable shielding state of the shielding curtain to occur, even during the inspection period.

[0014] In a preferred embodiment of the present invention, (2) the predetermined imaging area includes the main outer surface of the shielding curtain exposed in the opening and a part of the conveying surface of the conveyor located directly below the opening, and the first gap between the main outer surfaces of the shielding curtain and the second gap between the shielding curtain and the part of the conveying surface of the conveyor, which appear in the opening image, are recognized by the image feature recognition unit as predetermined image feature quantities, and a feature quantity storage unit is provided to store the recognized first gap and the second gap as reference image feature quantities, and the safety determination unit can be configured to determine the safety of the shielding function of the opening by comparing predetermined image feature quantities of the opening image recognized by the image feature recognition unit during the most recent predetermined period with the reference image feature quantities corresponding to at least the first gap and the second gap.

[0015] In this way, for example, in a curtain-like shielding curtain with a predetermined number of cracks (widths), if the gaps between the widths increase due to deterioration of the multiple strip-shaped widths, or if the gap at the lower end of the shielding curtain increases, then at least a first gap, which is the gap between the main outer surfaces of the shielding curtain, and a second gap, which is the gap between the shielding curtain and a part of the conveying surface of the conveyor, will appear in the opening image acquired under these conditions. At this time, the image feature recognition unit recognizes the first and second gaps as image features and stores them in the feature memory unit as reference image features, respectively. Then, the safety determination unit compares the image features of the opening image recognized by the image feature recognition unit in the current or recent predetermined period including the current period with the reference image features of at least the first and second gaps, and accurately determines the safety of the shielding function of the opening.

[0016] In a preferred embodiment of the present invention, (3) during a shielding period in which the object to be inspected does not pass through the opening, the opening imaging unit images the opening including the shielding state of the shielding curtain at a predetermined imaging period and repeatedly outputs an image of the opening including the shielding state of the shielding curtain, and the feature quantity storage unit is configured to store the predetermined image feature quantities of the opening image including the shielding state of the shielding curtain at a predetermined period, and the safety determination unit is configured to predict and determine the occurrence of an abnormality in the shielding state of the shielding curtain based on the predetermined image feature quantities of the opening image stored in the feature quantity storage unit at the predetermined period.

[0017] In this way, during the period when the aperture is shielded, an image of the aperture including the shielding state of the shielding curtain is repeatedly output at a predetermined imaging cycle, and predetermined image features of the outputted aperture image are sequentially stored in the feature memory at a predetermined cycle. Then, the safety determination unit predicts and determines the occurrence of an abnormality in the shielding state of the shielding curtain based on the predetermined image features of the multiple aperture images sequentially stored in the feature memory and the degree of deterioration of the shielding curtain and conveyor belt, which is understood as the degree of change of those features.

[0018] In a preferred embodiment of the present invention, (4) the feature memory unit stores the predetermined image feature quantities that appear in the image of the opening when the occlusion function of the opening is normal as reference image feature quantities for normal conditions, and stores the predetermined image feature quantities that appear in the image of the opening when the occlusion function of the opening is abnormal as reference image feature quantities for abnormal conditions, and the safety determination unit can determine the safety of the occlusion function of the opening by comparing the predetermined image feature quantities of the image of the opening recognized by the image feature recognition unit during the most recent predetermined period with the reference image feature quantities that include at least the reference image feature quantities for normal conditions and the reference image feature quantities for abnormal conditions.

[0019] In this case, the safety determination unit compares the image features of the aperture image recognized by the image feature recognition unit during the most recent predetermined period with the reference image features stored in the feature memory unit, which include at least the reference image features for normal conditions and the reference image features for abnormal conditions, to determine the safety of the aperture's occlusion function. If a significant change in image features toward the abnormal reference image features occurs in the aperture image recognized during the most recent predetermined period, it becomes possible to determine a decrease in the safety of the aperture's occlusion function.

[0020] In a preferred embodiment of the present invention, (5) the safety determination unit has a trained model that has learned to detect the deterioration and wear state of at least one of the deterioration and wear state of the shielding curtain and the deterioration and wear state of the conveyor belt constituting the conveyor using camera images that capture the deterioration and wear state, and the safety determination unit can determine the safety of the device based on the trained model and the opening image captured by the opening imaging unit.

[0021] In this case, since the system has a trained model that has learned to detect the deterioration and wear state of the shielding curtain and / or the conveyor belt using camera images, even when quantitative measurement of a specific location or specific type of deterioration is not easy, it is possible to accurately determine a significant deterioration state using an object detection method at the level of a skilled person's judgment. Therefore, based on the trained model and the aperture image captured by the aperture imaging unit, the safety determination unit can make an accurate safety determination.

[0022] In a preferred embodiment of the present invention, (6) the device has a trained model that has been pre-trained to recognize objects using camera images of the object to be inspected, and the safety determination unit can determine the safety of the device based on the trained model and the aperture image captured by the aperture imaging unit.

[0023] In this case, when an object other than the inspection object is recognized from the opening image based on the camera image by the learned model, it is recognized that an object other than the inspection object is approaching the opening, and it becomes possible to determine in advance a state in which the safety of the apparatus is impaired. On the other hand, when the inspection object is recognized as an object by the learned model from the opening image based on the camera image, it is recognized that the inspection object is approaching the opening, and it becomes possible to determine a state in which the safety of the apparatus is maintained.

[0024] In a preferred embodiment of the present invention, (7) the image feature recognition unit has a human body detection function for recognizing that a part of the human body is inserted into a predetermined imaging region including the opening based on the opening image, and when it is detected by the human body detection function of the image feature recognition unit that a part of the human body is inserted into the predetermined imaging region, the safety determination unit determines the safety of the apparatus based on the detection information by the human body detection function, and when it is detected by the human body detection function that a part of the human body is inserted into the predetermined imaging region, an inspection control unit is further provided that stops the X-ray irradiation in the X-ray imaging unit and the conveyance drive of the conveyor and outputs error information related to the X-ray inspection.

[0025] In this case, not only the determination of safety according to the degree of deterioration and wear of the shielding curtain and the conveyor belt but also the determination of safety based on the human body detection function can be accurately executed. When a part of the human body is inserted into the predetermined imaging region, it is quickly and accurately detected by the human body detection function, and it is possible to stop the X-ray irradiation in the X-ray imaging unit and the conveyance drive of the conveyor and quickly and accurately output error information related to the X-ray inspection.

[0026] In a preferred embodiment of the present invention, (8) a still image storage unit for storing still images obtained from camera images is further provided, wherein the image feature recognition unit performs image processing to recognize classifiable morphological features relating to the occlusion state of the opening and the detection information by the human body detection function that appear in the opening image as predetermined image feature quantities based on the still images stored in the still image storage unit, and the safety determination unit determines the safety relating to the occlusion state of the opening and the detection information by the human body detection function that appear in the opening image.

[0027] In this case, based on multiple still images obtained from camera footage at relatively short intervals, changes in the occlusion state of the opening and the insertion of parts of the human body can be detected quickly and accurately as changes in image features, enabling more accurate safety assessments.

[0028] To achieve the above objective, the X-ray inspection system according to the present invention is characterized by comprising: (9) an X-ray inspection apparatus comprising: a housing having at least one opening through which an object to be inspected conveyed in a predetermined direction by a conveyor passes; an X-ray imaging unit that images the object to be inspected with X-rays within the housing; an image processing unit that inspects the quality of the object to be inspected based on the X-ray image from the X-ray imaging unit; and a shielding curtain disposed in the opening; an aperture imaging camera independently provided outside the X-ray inspection apparatus to image a predetermined imaging area including the opening and output it as an opening image when at least the object to be inspected does not pass through the opening; an image feature recognition unit that recognizes classifiable morphological features relating to the shielding state of the opening that appear in the opening image from the aperture imaging camera as predetermined image feature quantities; and a safety determination unit that determines the safety of the shielding function of the opening by the shielding curtain based on the predetermined image feature quantities recognized by the image feature recognition unit.

[0029] With this configuration, when the object under inspection does not pass through the opening, the opening imaging camera captures a predetermined imaging area including the opening and outputs it as an opening image. When the image feature recognition unit recognizes classifiable morphological features related to the shielding state of the opening that appear in the opening image as predetermined image feature quantities, the safety determination unit accurately determines the safety of the shielding function of the opening by the shielding curtain based on these image feature quantities. As a result, this X-ray inspection system can reliably detect various deteriorations and abnormalities at the opening of an X-ray inspection device with a shielding curtain with a simple configuration, thereby significantly enhancing safety. [Effects of the Invention]

[0030] According to the present invention, it is possible to provide an X-ray inspection apparatus and an X-ray inspection system that can reliably detect various deteriorations and abnormalities in openings with shielding curtains with a simple configuration, thereby significantly enhancing safety. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic diagram of an X-ray inspection apparatus according to one embodiment of the present invention. [Figure 2] (a) is a partial perspective view showing the opening on the input side of the object to be inspected in an X-ray inspection apparatus according to one embodiment of the present invention, and (b) is a partial perspective view showing the opening on the output side of the object to be inspected in the same apparatus. [Figure 3] This is a partial plan view illustrating the configuration near the entrance opening in an X-ray inspection apparatus according to one embodiment of the present invention, including a portion of the preceding transport path. [Figure 4] This is a perspective view of a key part of an X-ray inspection apparatus according to one embodiment of the present invention, showing a shielding curtain unit that is detachably attached to the housing. [Figure 5] This is an explanatory diagram of the curtain arrangement in an X-ray inspection apparatus according to one embodiment of the present invention, including a partial cross-section of the conveying surface of the shielding curtain and conveyor as viewed in the conveying direction. [Figure 6]This is an explanatory diagram illustrating the overall form of deterioration, illustrating multiple different functional deterioration states of a shielding curtain in an X-ray inspection apparatus according to one embodiment of the present invention. [Figure 7] This is a diagram illustrating the deterioration patterns of multiple functional deterioration areas of a shielding curtain in an X-ray inspection apparatus according to one embodiment of the present invention, each at a predetermined image size. [Figure 8] This is a schematic diagram of an X-ray inspection system including an X-ray inspection apparatus according to another embodiment of the present invention. [Modes for carrying out the invention]

[0032] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. (One embodiment) Figures 1 to 5 show an X-ray inspection apparatus according to one embodiment of the present invention, and Figures 6 and 7 schematically illustrate multiple degradation modes of the X-ray shielding curtain in the apparatus.

[0033] First, let me explain its structure.

[0034] The X-ray inspection apparatus 1 shown in Figure 1 comprises an item transport unit 10 which is an inspection conveyor, an X-ray imaging unit 20 which takes X-ray images of the item to be inspected PF (item), an inspection control unit 30 which controls the item inspection process based on the X-ray images obtained from the imaging, a display and operation unit 40 which displays the output of the inspection control unit 30 and takes in operation inputs, and an opening monitoring unit 50 for ensuring safety. In addition, a front conveyor 14 is provided on the upstream side in the transport direction of the item transport unit 10, and a rear conveyor 15 which has a sorting device (not shown) attached to it is provided on the downstream side in the transport direction.

[0035] As shown in Figures 1 and 2, the article transport unit 10 transports the object to be inspected PF (article) in a predetermined transport direction, for example, in the transport direction indicated by the rightward arrow in Figure 1. For example, by motor-driving one of the rollers 12 or 13 that are stretched across a loop-shaped transport belt 11, the object to be inspected PF on the transport path 11a, which is the upper section of the belt, is transported at a predetermined speed and passed through the inspection area of ​​the X-ray imaging unit 20.

[0036] The object under test PF is not particularly limited, but could be, for example, food or medicine taken orally, and in this case, a product including its packaging.

[0037] The X-ray imaging unit 20 has an X-ray generator 21 and an X-ray detector 23 positioned above and below the transport path 11a of the article transport unit 10. In this case, the X-ray generator 21 and X-ray detector 23 are positioned opposite each other while being spaced apart vertically, but they may also be positioned spaced apart both vertically and horizontally. Alternatively, the article transport unit 10 may be composed of two belt conveyors aligned in the transport direction, with the X-ray detector positioned below the gap between the two belt conveyors.

[0038] The X-ray generator 21, although not shown in detail, has, for example, an X-ray tube 22 inside a metal box, and the X-ray tube 22 is immersed in insulating oil for cooling inside the box. This X-ray generator 21 is an X-ray irradiation unit that irradiates X-rays toward a predetermined inspection area in the transport path 11a of the object to be inspected PF, and in this embodiment, it has an X-ray tube 22 that irradiates X-rays downward from the vertically above side toward the object to be inspected PF.

[0039] The X-ray tube 22 is positioned such that its axial direction is oriented approximately parallel to the predetermined transport direction. On its cathode side, a negative DC potential is applied to light up a filament to a high temperature, causing electrons to be emitted and focused by a focusing electrode. On its anode side, a positive DC potential is applied to the target, accelerating the electrons from the filament with a high voltage and causing them to collide with the target, thereby generating X-rays within a predetermined energy range from the target.

[0040] The X-rays generated by the X-ray tube 22 are irradiated in a fan-beam shape, spreading downwards from the X-ray window at the bottom of the aforementioned box towards the inspection area into which the object to be inspected PF is transported, and in a line scanning direction perpendicular to the transport direction. The anode of the X-ray tube 22 may be of a fixed or rotating type. The X-ray imaging unit 20 also includes a filament power supply circuit (not shown) and a high-voltage circuit that applies a high voltage between the filament of the X-ray tube 22 and the target.

[0041] The X-ray detector 23, although not shown in detail, is a line sensor positioned, for example, directly beneath the transport path 11a of the transport belt 11. It comprises a scintillator that absorbs and emits X-rays of a predetermined energy (wavelength, penetrating power), and a photodiode array consisting of N (for example, several hundred) light-receiving elements arranged in a direction perpendicular to the transport direction of the object under inspection PF to receive light (scintillation light) from the scintillator. This X-ray detector 23 absorbs X-rays that are irradiated onto and transmitted through the object under inspection PF, causing it to emit light according to the transmission intensity of the X-rays, and outputs an electrical signal corresponding to the amount of light received by the photodiode at predetermined scanning cycles. It should be noted that the X-ray detector 23 is not limited to this indirect conversion method that indirectly converts X-rays into electrical signals; a direct conversion method is also possible.

[0042] The photodiode array of the X-ray detector 23 stores the photocurrents generated simultaneously by each of the N photodetectors for a predetermined storage time, and outputs a brightness detection signal Lx, which is a voltage signal, based on the charge corresponding to the product of the photocurrent and the storage time.

[0043] On the other hand, the X-ray imaging unit 20 has a roughly box-shaped radiation shielding structure housing 25 supported by legs 26, partially shown in Figure 2. The front side of the housing 25 is provided with a front cover 25a that can be opened towards the front on the transport path 11a. The left and right side walls 25b and 25d of the housing 25 are provided with an entrance 25c into which the object to be inspected W is brought in and an exit 25e out into which the object to be inspected W is discharged. The entrance 25c and exit 25e (hereinafter also simply referred to as openings 25c and 25e) are provided with a pair of opening-side shielding curtains 27 (curtain-shaped X-ray shielding members) that can close each opening in an X-ray shielding state.

[0044] As shown in Figure 4, at least one inner shielding curtain 28 is provided on the inside side of the housing 25, beyond the pair of opening-side shielding curtains 27, and located on the loading and / or loading side of the X-ray detector 23.

[0045] As shown in Figure 5, each shielding curtain 27 has a shielding width W2 that is wider than the passage width W1 of the transport path 11a, and is formed in a curtain-like shape with a predetermined number of strip-shaped width portions 27a. The multiple strip-shaped width portions 27a are arranged so that a predetermined number of 10 or more, as shown in Figure 5, or a predetermined number of less than 10, as shown in Figure 6, have the same height H2.

[0046] On the other hand, although not shown in detail, the inner shielding curtain 28 has a shielding width that is slightly wider than the passage width W1 of the transport path 11a, but slightly narrower than the shielding width W2 of the shielding curtain 27. On both ends of its shielding width, it has a predetermined number, for example, three strip-shaped width sections 27a and width sections 28a at both ends, and on the central side of its shielding width, it has six or more central width sections 28b that are shorter than the strip-shaped width sections 27a.

[0047] The material of these shielding curtains 27 and 28 may be, for example, X-ray shielding metals such as lead or stainless steel, which are kneaded into or embedded in resin or rubber. Specifically, for example, each width portion 27a, 28a, and 28b may be made of so-called lead rubber, forming a curtain-like structure. However, if the object to be inspected PF is not permitted to come into contact with lead, a plurality of strip-shaped metal plates, such as stainless steel plates, may be arranged in parallel adjacent to each other in the direction of the shielding width W2, and supported at the upper end of each width portion 27a, 28a, and 28b so as to be able to swing in the transport direction. Furthermore, multiple metal plates divided vertically may be connected at an intermediate height position of the width portion so as to be able to swing in the transport direction, allowing for multi-stage bending, or the lower end may be curved downstream in the transport direction.

[0048] The shading curtains 27 and 28 have their upper ends on detachable support plates 29A and 29B, respectively, at the ends of their width portions 27a, 28a and 28b. Alternatively, the width portions 27a, 28a and 28b may be suspended and supported from a horizontal axis supported by the support plates 29A and 29B.

[0049] The inspection control unit 30, although its detailed configuration is not shown, is hardware-configured to include, for example, a processor having a CPU, ROM, RAM, and I / O interface, an auxiliary storage device that stores control programs for performing various functions in a readable format in cooperation with the ROM, and timer circuits, driver circuits, etc. The CPU executes predetermined arithmetic processing and the control program while exchanging data with the RAM, etc., according to the software such as control programs and setting information stored in the ROM, etc. The various functions referred to here are the functions of each functional unit and means for X-ray output control, X-ray image data generation, inspection control, and display output control, etc., as described below. Furthermore, the hardware referred to here may include FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), GPU (Graphics Processing Unit), etc.

[0050] As shown in Figure 1, the inspection control unit 30 is composed of an inspection image acquisition unit 31, a belt surface correction unit 32, an image processing unit 33, and an inspection determination unit 35.

[0051] Specifically, the inspection image acquisition unit 31 acquires a brightness detection signal Lx for each line scan from the photodiode array of the X-ray detector 23 and generates X-ray image data DpX. The belt surface correction unit 32 corrects the value of the brightness detection signal Lx from the X-ray detector 23 to match the white reference value for each of the N photoreceiving elements when the X-rays from the X-ray generator 21 pass only through the transport path 11a, which is the belt surface before the object PF under inspection is brought in (when there is no object PF under inspection), that is, it performs a light reception sensitivity correction on the belt surface (so-called shading correction).

[0052] The image processing unit 33 has, for example, known image processing functions for detecting foreign objects, or image processing functions for volume measurement and relative mass measurement. The inspection and determination unit 35 determines, based on the measurement results from the image processing unit 33, whether or not foreign objects are mixed in the object PF under inspection, or whether or not the measured volume or mass falls within a predetermined tolerance range relative to the standard value.

[0053] The display and operation unit 40 is a touch panel type, for example, composed of an LCD (Liquid Crystal Display), and combines the functions of a display means and an operation input means. This display and operation unit 40 is not limited to a touch panel integrated into the X-ray inspection device 1, but may also be provided in the form of a portable tablet-type information terminal, or may be additionally installed in the form of a display and operation panel separate from the touch panel integrated into the X-ray inspection device 1.

[0054] The aperture monitoring unit 50 includes, for example, aperture imaging cameras 51 and 52 (aperture imaging unit), which are visible light cameras with a built-in DSP chip for signal processing, and a camera image input unit 53, an image feature recognition unit 54, an image feature storage unit 55, a safety determination unit 56, and an abnormality occurrence prediction unit 57, which are all part of the inspection control unit 30 and consist of an FPGA and work memory, etc.

[0055] The aperture imaging camera 51 on the entrance 25c side is positioned above the transport path 11a of the article transport unit 10 and upstream of the predetermined transport position of the object to be inspected PF, for example, the position where the object to be inspected PF is detected entering the X-ray imaging unit 20 by the article detection sensor 39 such as a photoelectric sensor. The camera images the imaging area R1 on the entrance 25c side of the housing 25, including the appearance of the shielding curtain 27 on the entry side that blocks the entrance 25c and shields the X-rays, and outputs aperture imaging data Di1.

[0056] Furthermore, the aperture imaging camera 52 on the outlet 25e side is positioned above and downstream of the transport path 11a of the article transport section 10, so that it images the imaging area R2 on the outlet 25e side of the housing 25, including the appearance of the shielding curtain 27 on the output side that blocks the outlet 25e and shields X-rays, and outputs aperture imaging data Di2.

[0057] The imaging timing for the imaging area R1 on the entrance 25c side by the aperture imaging camera 51 occurs when, at least, the object under inspection PF does not pass through the entrance 25c and exit 25e, which are openings. More specifically, for example, when the front cover 25a is closed and the waiting time for the object under inspection PF to be detected by the object detection sensor 39 exceeds a predetermined waiting time, and the shielding state of the entrance 25c by the shielding curtain 27 on the entrance side is stable. Alternatively, when the front cover 25a is closed and the number of objects under inspection PF of a predetermined type set as the target product for inspection in the inspection control unit 30 has reached the set number of inspections, and inspection is temporarily suspended for product switching, etc. Hereinafter, the period during which imaging timing occurs when no object passes through is also referred to as the shielding period.

[0058] As described above, the aperture imaging data Di1 and Di2 from the imaging cameras 51 and 52 are taken into the camera image input unit 53 of the aperture monitoring unit 50 when the object under inspection PF does not pass through the entrance 25c and exit 25e, and are then taken into the image feature recognition unit 54 via this camera image input unit 53.

[0059] The camera image input unit 53 can acquire, for example, item detection information from the item detection sensor 39, and based on the item detection timing, it can identify the predetermined imaging timing mentioned above, that is, when at least the object to be inspected PF does not pass through the openings, the entrance 25c and the exit 25e, and acquire the aperture images Dg1 and Dg2 from the aperture imaging cameras 51 and 52.

[0060] The image feature recognition unit 54 is configured to perform a process of recognizing classifiable morphological features of the shading curtain 27 and its surroundings that relate to the shading state of the apertures 25c and 25e appearing in the aperture images Dg1 and Dg2 from the aperture imaging cameras 51 and 52 as predetermined image feature quantities fr1 and fr2.

[0061] Here, the classifiable morphological features relating to the shielding state of the openings 25c and 25e are such that when the shielding curtain 27 performs its X-ray shielding function while closing each opening 25c and 25e, the shapes of the multiple width portions 27a of the shielding curtain 27 and the various parts of the conveyor belt 11 that constitute the conveyor path 11a are substantially the same, and the images reflecting these shapes can be classified. Furthermore, the type of deterioration of the shielding curtain 27 in each classification can be identified from external morphologies such as the gaps between the multiple width portions 27a and the gaps between the shielding curtain 27 and the conveyor belt 11a. Thus, these are morphological features that allow for the classification and identification of the deterioration state of the multiple width portions 27a of the shielding curtain 27 and the conveyor belt 11 that constitutes the conveyor path 11a.

[0062] More specifically, as shown in Figures 4 to 6, for example, in a shielding curtain 27 of a predetermined number of cracks (widths) in the opening images Dg1 and Dg2, if deterioration such as warping, twisting, or cracking occurs in any of the multiple strip-shaped width portions 27a, the gap g in the substantially horizontal direction between the outer surfaces (between the main outer surfaces) of the shielding curtain 27 increases due to this deterioration (see Figure 6(a)), or the lower end of the shielding curtain 27 may tear or have partial defects (see Figures 6(b) and (c)), or the gap gt in the substantially vertical direction between the lower end of the shielding curtain 27 and the conveying path 11a may increase due to deterioration such as wear, tearing, or defects in the conveying path 11a, which is a part of the conveying surface of the conveyor. In the opening images Dg1 and Dg2 obtained under this deteriorated state, at least a first gap gs, which is the gap between the main outer surfaces of multiple width portions 27a of the shielding curtain 27, and a second gap gt, which is the gap between the shielding curtain 27 and the conveying path 11a (partially the conveying surface) of the conveying belt 11, will appear.

[0063] At this time, the image feature recognition unit 54 recognizes the first and second gaps gs and gt as predetermined image feature quantities fr1 and fr2 that appear in the opening images Dg1 and Dg2, respectively, and the feature quantity storage unit 55 stores them as reference image feature quantities fc1 and fc2, respectively.

[0064] Then, the safety determination unit 56 compares predetermined image feature quantities fr1 and fr2 of the opening images Dg1 and Dg2 recognized by the image feature recognition unit 54 with reference image feature quantities fc1 and fc2 of the first and second gaps gs and gt stored in the feature quantity storage unit 55, and based on the results, the safety of the shielding function of the openings 25c and 25e by the shielding curtain 27 is accurately determined from multiple perspectives.

[0065] More specifically, predetermined imaging regions R1 and R2 include multiple width portions 27a (main outer surfaces) of the loading and unloading shielding curtains 27 exposed within the openings 25c and 25e, respectively, and the transport path 11a (part of the conveying surface of the conveyor) located directly below the openings 25c and 25e. When a first gap gs between the main outer surfaces of the shielding curtains 27 and a second gap gt between the shielding curtains 27 and the transport path 11a of the transport belt 11 appear in the opening images Dg1 and Dg2, these first and second gaps gs and gt are recognized by the image feature recognition unit 54 as predetermined image feature quantities fr1 and fr2, respectively, and the recognized first gap gs and second gap gt are stored by the feature quantity storage unit 55 as reference image feature quantities fc1 and fc2, respectively.

[0066] The safety determination unit 56 then compares predetermined image feature quantities fr1 and fr2 of the opening images Dg1 and Dg2 recognized by the image feature recognition unit 54 in the current or recent predetermined period including the current period with reference image feature quantities fc1 and fc2 stored in the feature quantity storage unit 55 corresponding to at least the first gap gs and the second gap gt, and determines the safety of the shielding function of the openings 25c and 25e based on whether or not a significant change has occurred between them.

[0067] The anomaly occurrence prediction unit 57 repeatedly outputs aperture images Dg1 and Dg2 by having aperture imaging cameras 51 and 52 capture images of the apertures 25c and 25e at predetermined imaging intervals each time the object under inspection PF does not pass through the apertures 25c and 25e, and the reference image features fc1 and fc2 are stored in the feature memory unit 55 at predetermined intervals. As a result, the changes in the reference image features fc1 and fc2 stored in the feature memory unit 55 can be compared as feature changes over a relatively long period, and the occurrence of anomalies in the occlusion state of the occlusion curtain 27 can be predicted and determined according to the degree of change in the features over a relatively long period. The anomaly occurrence prediction unit 57 may also store some of the older stored data that exceeds the storage period of the reference image features fc1 and fc2 in the feature memory unit 55 for a longer storage period and time interval than the feature memory unit 55.

[0068] On the other hand, the feature memory unit 55 stores predetermined image features fr1 and fr2 that appear in the aperture images Dg1 and Dg2 when the occlusion function of the apertures 25c and 25e is normal, as normal reference image features fc1 and fc2 (normal reference image features), and stores predetermined image features fr1 and fr2 that appear in the aperture images Dg1 and Dg2 when the occlusion function of the apertures 25c and 25e is abnormal, as abnormal reference image features fc1 and fc2 (abnormal reference image features). Therefore, the safety determination unit 56 can determine the safety of the occlusion function of the apertures 25c and 25e by comparing the predetermined image features fr1 and fr2 of the aperture images Dg1 and Dg2 recognized by the image feature recognition unit 54 in the current or recent predetermined period including the current, with the reference image features fc1 and fc2, which include at least the normal reference image features and the abnormal reference image features.

[0069] The image feature recognition unit 54 also has a trained model 54a that has learned to detect such deterioration and wear conditions using camera images that capture at least one of the deterioration and wear conditions of the shielding curtain 27 and the conveyor belt 11 that constitutes the inspection conveyor. The safety determination unit 56 is able to determine the safety of the device based on the trained model 54a in the image feature recognition unit 54 and the aperture images Dg1 and Dg2 captured by the aperture imaging cameras 51 and 52.

[0070] In other words, the object detection referred to in the present invention is an object detection method that detects image features fc1 and fc2 from the aperture image Dg1 using rule (logic)-based techniques such as pattern matching using the first gap gs and the second gap gt described above. However, it is not limited to this, and may also be an object detection algorithm obtained by AI learning using a neural network, for example, an object detection method known as YOLO (You Only Look Once) or SSD (Single Shot Detector). By detecting predetermined image features fr1 and fr2 from the aperture images Dg1 and Dg2 through object detection, the deterioration state of multiple width portions 27a of each shading curtain 27 and the transport path 11a that appear in the aperture images Dg1 and Dg2 can be accurately classified and recognized. In this case, not only imaging data that intelligently captures the functionally deteriorated parts of the shielding curtain as shown in Figure 6, but also partial image data of a predetermined image size that captures multiple types of functionally deteriorated parts of the width portion 27a of the shielding curtain 27, as shown in Figure 7, or deteriorated parts of the conveyor belt 11 and other parts, can be prepared as a training dataset (image data and annotation data) for object detection and object recognition and used for training. Based on the feature quantities of these deterioration forms (features corresponding to unevenness, peeling, abrasion, surface deterioration, etc.), the ability to classify and identify diverse deterioration forms can be improved.

[0071] The image feature recognition unit 54 may have a pre-trained model 54a that has been trained in advance to recognize objects using camera images of the object PF under inspection captured by aperture imaging cameras 51 and 52, and the safety determination unit 56 may determine the safety of the device by distinguishing between a specific object and other objects or parts of the human body, etc., based on the pre-trained model 54a and aperture images Dg1 and Dg2 captured by aperture imaging cameras 51 and 52.

[0072] For example, the image feature recognition unit 54 has a human body detection function that recognizes that a part of the human body B, as shown in Figure 3, has been inserted into either of the predetermined imaging areas R1 or R2, which include the apertures 25c and 25e, based on the aperture images Dg1 and Dg2. When the human body detection function of the image feature recognition unit 54 detects that a part of the human body B has been inserted into the predetermined imaging area R1 or R2, the safety determination unit 56 and the abnormality occurrence prediction unit 57 determine the safety of the device based on the detection information from the human body detection function. If they determine that an abnormality has occurred due to a part of the human body B being inserted into the predetermined imaging area R1 or R2, the inspection control unit 30 stops the X-ray irradiation by the X-ray imaging unit 20 and the transport drive of the transport belt 11, and outputs error information related to the X-ray inspection to the display operation unit 40.

[0073] The camera image input unit 53 is composed of the aforementioned FPGA and work memory, and also functions as a still image storage unit 53a that stores still images obtained from camera images (moving images) from the aperture imaging cameras 51 and 52, which are visible light cameras. The image feature recognition unit 54 performs image processing to recognize classifiable morphological features related to the occlusion state of the apertures 25c and 25e appearing in the aperture images Dg1 and Dg2 and detection information by the human body detection function as predetermined image feature quantities fr1 and fr2 based on the still images stored in the still image storage unit 53a. The safety determination unit 56 is capable of determining the safety related to the occlusion state of the apertures 25c and 25e appearing in the aperture images Dg1 and Dg2 and detection information by the human body detection function.

[0074] The safety determination unit 56 outputs a determination result (OK / NG), and the abnormal occurrence prediction unit 57 outputs an alarm that an abnormal occurrence is predicted, to the display operation unit 40 and the alarm output unit 60 (such as a warning light), respectively, and the display output and alarm output are executed.

[0075] In this context, the aperture imaging cameras 51 and 52 are simply external imaging units that image the apertures 25c and 25e from outside the device. However, additional cameras may be added on the inside of the X-ray imaging unit 20 to image the shielding state of the shielding curtain 27.

[0076] Next, I will explain how it works.

[0077] In the X-ray inspection apparatus 1 of this embodiment, configured as described above, during the aforementioned shielding period in which at least the object to be inspected PF does not pass through the openings, the entrance 25c and the exit 25e, when, for example, a specific object to be inspected PF among multiple objects to be inspected PF being transported is detected by the object detection sensor 39 and a predetermined waiting time has elapsed, and the shielding state of the entrance 25c by the shielding curtain 27 on the entrance side has stabilized, and when, after a predetermined time has elapsed, the shielding state of the exit 25e by the shielding curtain 27 on the exit side has stabilized, the aperture imaging cameras 51 and 52 image the imaging areas R1 and R2 on the entrance 25c and exit 25e sides so as to show the respective shielding curtains 27. Alternatively, when the front cover 25a is closed, and the number of inspected items PF of the inspected variety has reached the set number of inspections, and the inspection is temporarily suspended for variety switching or the like, the aperture imaging cameras 51 and 52 image the imaging areas R1 and R2 on the entrance 25c and exit 25e sides so as to show the respective shielding curtains 27.

[0078] At this time, aperture imaging data Di1 and Di2 output from aperture imaging cameras 51 and 52 are taken into the camera image input unit 53, and aperture images Dg1 and Dg2 captured in the current or predetermined period including the current period are output from the camera image input unit 53 and taken into the image feature recognition unit 54.

[0079] Then, based on the captured aperture images Dg1 and Dg2, the image feature recognition unit 54 detects the aforementioned first gaps gs and second gaps gt, etc., around the respective shading curtains 27 within the imaging regions R1 and R2 as predetermined image feature quantities fr1 and fr2 that can morphologically classify and identify the deterioration state of the shading curtains 27, etc., and stores them in the feature quantity storage unit 55 as corresponding reference image feature quantities fc1 and fc2.

[0080] Furthermore, as described above, based on the predetermined image features fr1 and fr2 detected in the current or predetermined period including the current, and the reference image features fc1 and fc2 stored in the feature memory unit 55, the safety determination unit 56 makes a safety determination, and the abnormal occurrence prediction unit 57 predicts the occurrence of an abnormality. The safety determination result from the safety determination unit 56 and the alarm output from the abnormal occurrence prediction unit 57 are output to the display operation unit 40 and the alarm output unit 60, such as a warning light, when necessary.

[0081] Thus, in this embodiment, during the shielding period when the object under inspection PF does not pass through the openings, the entrance 25c and exit 25e, the aperture imaging cameras 51 and 52 capture predetermined imaging areas R1 and R2 including the openings 25c and 25e, and output them as aperture images Dg1 and Dg2. Classifiable morphological features relating to the shielding state of the openings 25c and 25e that appear in the aperture images Dg1 and Dg2 are recognized by the image feature recognition unit 54 as predetermined image feature quantities fr1 and fr2, and projected into the feature space as feature vectors, for example, the safety determination unit 56 accurately determines the safety of the shielding function of the openings 25c and 25e by the shielding curtain 27 based on these image feature quantities fr1 and fr2. Therefore, the X-ray inspection apparatus 1 can reliably detect various deteriorations and abnormalities in the openings 25c and 25e with the shielding curtain 27 with a simple configuration, and can sufficiently enhance safety.

[0082] Furthermore, in this embodiment, if deterioration such as warping, twisting, or cracking occurs in any of the multiple strip-shaped width portions of the shielding curtain 27 with a predetermined number of cracks, and this deterioration increases the substantially horizontal gap gs between the main outer surfaces of the shielding curtain 27, or if deterioration such as tearing or partial loss of the lower end of any width portion 27a of the shielding curtain 27, or wear, tearing, or loss of a part of the conveying surface of the conveying belt 11 increases the substantially vertical gap gt between the lower end of the shielding curtain 27 and the conveying path 11a, then at least a first gap gs, which is the gap between the main outer surfaces of the shielding curtain 27, and a second gap gt, which is the gap between the shielding curtain 27 and a part of the conveying surface of the conveyor, will appear in the opening images Dg1 and Dg2 acquired under these deteriorated conditions.

[0083] At this time, the image feature recognition unit 54 recognizes the first and second gaps using image features and stores them in the feature memory unit 55 as reference image features fc1 and fc2, respectively. The safety determination unit 56 then compares the image features of the opening images Dg1 and Dg2 recognized by the image feature recognition unit 54 during the current or most recent predetermined period including the current one with the reference image features fc1 and fc2 of at least the first and second gaps, thereby accurately determining the safety of the shielding function of the openings 25c and 25e.

[0084] Furthermore, in this embodiment, during the shielding period when the object under inspection PF does not pass through the openings 25c and 25e, opening images Dg1 and Dg2, including the shielding state of the shielding curtain 27, are repeatedly output, and predetermined image features fr1 and fr2 that appear in these opening images Dg1 and Dg2 are stored in the feature memory unit 55 as reference image features fc1 and fc2. Therefore, not only is the safety determination unit 56 able to make safety determinations, but the abnormality occurrence prediction unit 57 can also predict and determine the occurrence of abnormalities in the shielding state of the shielding curtain 27 based on the reference image features fc1 and fc2 stored in the feature memory unit 55.

[0085] In other words, during the shielding period of the apertures 25c and 25e, aperture images Dg1 and Dg2, which include the shielding state of the shielding curtain 27, are repeatedly output at a predetermined imaging cycle, and predetermined image feature quantities fr1 and fr2 of the output aperture images Dg1 and Dg2 are sequentially stored in the feature quantity storage unit 55. Then, the safety determination unit 56 predicts and determines the occurrence of an abnormality in the shielding state of the shielding curtain 27 based on the predetermined image feature quantities fr1 and fr2 of the multiple aperture images Dg1 and Dg2 sequentially stored in the feature quantity storage unit 55 as reference image feature quantities fc1 and fc2, and the degree of deterioration of the shielding curtain 27 and the transport belt 11, which is understood as the degree of change.

[0086] In addition, in this embodiment, the feature memory unit 55 stores predetermined image feature quantities fr1 and fr2 that appear in the aperture images Dg1 and Dg2 when the occlusion function of the apertures 25c and 25e is normal as reference image feature quantities for normal operation, and stores predetermined image feature quantities fr1 and fr2 that appear in the aperture images Dg1 and Dg2 when the occlusion function of the apertures 25c and 25e is abnormal as reference image feature quantities for abnormal operation. Therefore, the safety determination unit 56 compares the image feature quantities of the aperture images Dg1 and Dg2 recognized by the image feature recognition unit 54 during the most recent predetermined period with the reference image feature quantities fc1 and fc2 stored in the feature memory unit 55, which include at least the reference image feature quantities for normal operation and the reference image feature quantities for abnormal operation, to determine the safety of the occlusion function of the apertures 25c and 25e. Furthermore, if significant changes in image features occur in the reference image features of the aperture images Dg1 and Dg2 recognized during the most recent predetermined period, a decrease in the safety of the occlusion function of apertures 25c and 25e will be determined.

[0087] Furthermore, in this embodiment, the image feature recognition unit 54 has a trained model 54a that has learned to detect the deterioration and wear state of at least one of the deterioration and wear state of the shielding curtain 27 and the deterioration and wear state of the conveyor belt 11 using camera images, and the safety determination unit 56 determines the safety of the device based on the trained model 54a and the aperture images Dg1 and Dg2 captured by the aperture imaging cameras 51 and 52. Therefore, even if the deterioration and wear state of the shielding curtain 27 and / or the conveyor belt 11 is not easily measured quantitatively as a specific location or specific type of deterioration, it is possible to accurately determine a significant deterioration state at the level of a skilled person's judgment using an object detection method. In other words, the safety determination unit 56 can make an accurate safety determination based on the trained model 54a and the aperture images Dg1 and Dg2 captured by the aperture imaging cameras 51 and 52.

[0088] Furthermore, in this embodiment, the image feature recognition unit 54 has a pre-trained model 54a that has been trained in advance to recognize objects using camera images of the object under inspection PF, and the safety determination unit 56 determines the safety of the device based on the pre-trained model 54a and the aperture images Dg1 and Dg2 captured by the aperture imaging cameras 51 and 52. Therefore, if the pre-trained model 54a recognizes an object other than the object under inspection PF from the aperture images Dg1 and Dg2 based on the camera images, it will be recognized that something other than the object under inspection PF is approaching the apertures 25c and 25e, and it will be possible to determine in advance that the safety of the device is compromised. On the other hand, if the pre-trained model 54a recognizes the object under inspection PF from the aperture images Dg1 and Dg2 based on the camera images, it will be recognized that the object under inspection PF is approaching the apertures 25c and 25e, and it will be possible to determine that the safety of the device is maintained.

[0089] Furthermore, in this embodiment, when the human body detection function of the image feature recognition unit 54 detects that a part of the human body B has been inserted into predetermined imaging areas R1 and R2, the safety determination unit 56 determines the safety of the device based on the human body detection information from the image feature recognition unit 54. Therefore, when the human body detection function of the image feature recognition unit 54 detects that a part of the human body B has been inserted into predetermined imaging areas R1 and R2, the inspection control unit 30 stops the X-ray irradiation by the X-ray imaging unit 20 and the conveyor transport drive by the transport belt 11, and also executes control to output error information related to the X-ray inspection to the display operation unit 40 and the alarm output unit 60. Consequently, not only is it possible to accurately determine safety based on the degree of deterioration of the shielding curtain 27 and the transport belt 11, but safety can also be accurately determined based on the human body detection function. This effectively prevents human errors in emergency situations.

[0090] Furthermore, in this embodiment, a still image storage unit 53a is provided to store still images obtained from camera footage. The image feature recognition unit 54 recognizes classifiable morphological features related to the occlusion state of the openings 25c and 25e appearing in the opening images Dg1 and Dg2, and detection information by the human body detection function, as predetermined image feature quantities fr1 and fr2 based on the still images stored in the still image storage unit 53a. Therefore, based on multiple still images obtained from camera footage at relatively short intervals, changes in the occlusion state of the openings 25c and 25e and insertion movements of parts of the human body can be detected quickly and accurately as changes in predetermined image feature quantities fr1 and fr2 relative to reference image feature quantities fc1 and fc2, enabling more accurate safety determination.

[0091] Thus, according to this embodiment, it is possible to provide an X-ray inspection device 1 that can reliably detect various deteriorations and abnormalities in the openings 25c and 25e having a shielding curtain 27 with a simple configuration, thereby significantly enhancing safety.

[0092] (Other embodiments) Figure 8 shows an X-ray inspection system according to another embodiment of the present invention. Furthermore, for configurations identical or similar to the aforementioned embodiment, the same reference numerals as those used for the corresponding components in the embodiment shown in Figures 1 to 7 are used, and redundant detailed explanations are omitted.

[0093] The X-ray inspection system 2 of this embodiment comprises an X-ray inspection apparatus 100 having a housing 25 having at least one opening 25c, 25e through which an object to be inspected PF, which is transported in a predetermined direction by an article transport unit 10, passes; an X-ray imaging unit 20 that images the object to be inspected PF with X-rays within the housing 25; an image processing unit 33 that inspects the quality of the object to be inspected PF based on the X-ray image Dpx from the X-ray imaging unit 20; and shielding curtains 27 disposed in the openings 25c, 25e.

[0094] The X-ray inspection system 2 of this embodiment further includes a management PC 150 having a display operation unit 140, aperture imaging cameras 151 and 152, a camera image input unit 153, an image feature recognition unit 154, a feature quantity storage unit 155, a safety determination unit 156, and an abnormality occurrence prediction unit 157, as well as an alarm output unit 160 such as an alarm light. This management PC 150 is configured to perform functions similar to those of the aperture monitoring unit 50 in one embodiment.

[0095] Here, aperture imaging cameras 151 and 152 are independently provided outside the X-ray inspection apparatus 100 so as to image predetermined imaging areas R1 and R2 including the apertures 25c and 25e during a shielding period in which the object under inspection PF does not pass through the apertures 25c and 25e, and output them as aperture images Dg1 and Dg2.

[0096] The camera image input unit 153 acquires item detection information from the item detection sensor 39, identifies the shielding period during which the object to be inspected PF does not pass through the entrance 25c and exit 25e, and can acquire aperture images Dg1 and Dg2 from the aperture imaging cameras 51 and 52.

[0097] The image feature recognition unit 154 recognizes classifiable morphological features such as occlusion curtains 27 related to the occlusion state of apertures 25c and 25e that appear in aperture images Dg1 and Dg2 from aperture imaging cameras 151 and 152 as predetermined image feature quantities fr1 and fr2.

[0098] The feature memory unit 155 stores predetermined image features fr1 and fr2 that appear in aperture images Dg1 and Dg2 with respect to the deterioration of the occlusion function of apertures 25c and 25e as reference image features fc1 and fc2. Each time predetermined image features fr1 and fr2 are output from the image feature recognition unit 154, they can be stored as reference image features fc1 and fc2.

[0099] The safety determination unit 156 determines the safety of the shielding function of the openings 25c and 25e by the shielding curtain 27 based on predetermined image feature quantities fr1 and fr2 recognized by the image feature recognition unit 154 and reference image feature quantities fc1 and fc2 stored in the feature quantity storage unit 155.

[0100] The anomaly occurrence prediction unit 157 can compare the changes in reference image features fc1 and fc2 stored in the feature memory unit 155 at predetermined intervals as feature changes over a relatively long period, when the aperture imaging cameras 151 and 152 repeatedly capture images of the apertures 25c and 25e at predetermined imaging intervals and output aperture images Dg1 and Dg2 each time the object under inspection PF does not pass through the apertures 25c and 25e during the shielding period. Based on the degree of change in these features over a relatively long period, the unit can predict and determine the occurrence of an anomaly in the shielding state of the shielding curtain 27.

[0101] In this embodiment as well, during the shielding period when the object under inspection PF does not pass through the openings 25c and 25e, predetermined imaging areas R1 and R2 including the openings 25c and 25e are imaged by the aperture imaging cameras 151 and 152 and imported into the management PC as aperture images Dg1 and Dg2 via the camera image input unit 153. When the image feature recognition unit 154 recognizes classifiable morphological features related to the shielding state of the openings 25c and 25e that appear in the aperture images Dg1 and Dg2 as predetermined image feature quantities fr1 and fr2, the safety determination unit 56 compares these with reference image feature quantities fc1 and fc2 stored in the feature quantity storage unit 155 to accurately determine the safety of the shielding function of the openings 25c and 25e by the shielding curtain 27. As a result, the X-ray inspection system 2 can reliably detect various deteriorations and abnormalities at the openings of the X-ray inspection apparatus 100 having a shielding curtain 27 with a simple configuration, thereby significantly enhancing safety.

[0102] It goes without saying that the aforementioned X-ray inspection system 2 can be configured as an item inspection system in which other item inspection devices, such as a weight sorter or a metal foreign object detection device, are arranged on the same inspection line. Furthermore, although the aperture imaging cameras 51, 52, 151, and 152 are all visible light cameras, depending on the type of item PF being inspected, any camera capable of visualizing changes in the morphological characteristics of the opening in a shielded state is acceptable, and it is certainly not limited to visible light cameras. In addition, it is conceivable to provide a near-infrared camera or a multispectral camera for human body detection. Also, in Figure 2, the aperture imaging cameras 51 and 52 are positioned to image the entrance 25c from the side and the exit 25e from above, but it is certainly possible to position them at the opposite opening. In addition, each of the imaging cameras 51 and 52 only needs to be positioned and positioned so that it can image the entire opening, including the appearance of the shielding curtain and the gap between the shielding curtain and the conveyor belt surface, without obstructing the transport of the object under inspection, and it goes without saying that the installation location and number of the aperture imaging cameras 51, 52, 151, and 152, as well as the line of sight and field of view during imaging, are arbitrary.

[0103] As described above, the present invention provides an X-ray inspection apparatus and X-ray inspection system that can reliably detect various deteriorations and abnormalities in openings with shielding curtains with a simple configuration, thereby significantly enhancing safety. The present invention is useful for X-ray inspection apparatuses and X-ray inspection systems in general that inspect the quality state of an object based on an X-ray inspection image of the object taken with X-rays. [Explanation of Symbols]

[0104] 1. X-ray inspection device 2 X-ray inspection system 10. Goods transport section (conveyor) 11. Conveyor belt 11a Conveyor path (part of the conveyor's conveying surface) 12, 13 Laura 14 Front Conveyor 15. Downstream conveyor 20 X-ray imaging section 21 X-ray generator 22 X-ray tube 23 X-ray detector 25 cabinets 25a Front cover 25b, 25d Left and right side walls 25c Loading entrance (opening) 25e Exit (opening) 26 Legs 27. Shielding Curtains 27a Width section (multiple width sections, main outer surface) 28. Inner blackout curtain 28a Width portion at both ends 28b Width portion on the central side 29A, 29B Support plate 30 Inspection Control Unit 31. Inspection Image Acquisition Unit 32 Belt surface correction section 33 Image Processing Unit 35. Inspection and Judgment Unit 39. Item detection sensor 40 Display operation section 50 Aperture monitoring section 51, 52 Aperture imaging camera (aperture imaging unit, morphological feature imaging unit) 53 Camera image input section 53a Still image storage unit 54 Image Feature Recognition Unit 54a Pre-trained model 55 Feature Memory Unit 56 Safety Judgment Department 57 Anomaly Occurrence Prediction Unit 60 Alarm output section 100 X-ray inspection equipment 140 Display operation section 150 Management PC 151, 152 Aperture imaging camera 153 Camera image input section 154 Image Feature Recognition Unit 155 Feature Memory Unit 156 Safety Judgment Department 157 Anomaly Occurrence Prediction Unit 160 Alarm output section B Part of the human body Di1, Di2 aperture imaging data Dg1, Dg2 Aperture Images fc1, fc2 Reference image features (classifiable characteristic morphology, image features) fr1, fr2: predetermined image features gs First gap GT Second Gap H2 Height (height of the width portion) Lx Brightness detection signal PF Inspected Items R1, R2 imaging area W1 Conveyor path width (aisle width) W2 Shading width (curtain width)

Claims

1. An X-ray inspection apparatus comprising: a housing (25) having at least one opening (25c, 25e) through which an object to be inspected (PF) being transported in a predetermined direction by a conveyor passes; an X-ray imaging unit that images the object to be inspected with X-rays within the housing; an image processing unit that inspects the quality of the object to be inspected based on the X-ray image (Dpx) from the X-ray imaging unit; and a shielding curtain disposed in the opening, An aperture imaging unit (51, 52) captures a predetermined imaging area (R1, R2) including the opening and outputs it as an aperture image (Dg1, Dg2) when at least the object to be inspected does not pass through the opening, An image feature recognition unit (54) recognizes classifiable morphological features relating to the occlusion state of the aperture that appear in the aperture image from the aperture imaging unit as predetermined image feature quantities (fr1, fr2), An X-ray inspection apparatus further comprising: a safety determination unit (56) that determines the safety of the shielding function of the opening by the shielding curtain based on the predetermined image feature quantity recognized by the image feature recognition unit.

2. The predetermined imaging area includes the main outer surface (27a) of the shielding curtain exposed within the opening and a portion of the conveying surface (11a) of the conveyor located directly below the opening. The first gap (gs) between the main outer surfaces of the shielding curtain and the second gap (gt) between the shielding curtain and the partial conveying surface of the conveyor, which appear in the opening image, are recognized by the image feature recognition unit as predetermined image feature quantities, A feature memory unit (55) is provided that stores the recognized first gap and the second gap as reference image features (fc1, fc2), respectively. The X-ray inspection apparatus according to claim 1, characterized in that the safety determination unit determines the safety of the shielding function of the opening by comparing a predetermined image feature quantity of the opening image recognized by the image feature recognition unit during the most recent predetermined period with the reference image feature quantity corresponding to at least the first gap and the second gap.

3. During the shielding period in which the object to be inspected does not pass through the opening, the opening imaging unit images the opening, including the shielding state of the shielding curtain, at a predetermined imaging cycle, and repeatedly outputs the opening image including the shielding state of the shielding curtain, The feature quantity storage unit is configured to store and accumulate the predetermined image feature quantities of the opening image, including the occlusion state of the occlusion curtain, at a predetermined period. The X-ray inspection apparatus according to claim 2, characterized in that the safety determination unit predicts and determines the occurrence of an abnormality in the shielding state of the shielding curtain based on the predetermined image features of the opening image stored in the feature memory unit at a predetermined period.

4. The feature memory unit stores the predetermined image feature quantities that appear in the aperture image when the aperture's occlusion function is normal as reference image feature quantities for normal operation, and stores the predetermined image feature quantities that appear in the aperture image when the aperture's occlusion function is abnormal as reference image feature quantities for abnormal operation. The X-ray inspection apparatus according to claim 2 or 3, characterized in that the safety determination unit determines the safety of the shielding function of the opening by comparing a predetermined image feature quantity of the opening image recognized by the image feature recognition unit during the most recent predetermined period with the reference image feature quantity which includes at least the reference image feature quantity for normal conditions and the reference image feature quantity for abnormal conditions.

5. The system has a trained model (54a) that has learned to detect the deterioration and wear state of at least one of the deterioration and wear state of the shielding curtain and the deterioration and wear state of the conveyor belt constituting the conveyor using camera images that capture the deterioration and wear state, The X-ray inspection apparatus according to claim 1 or 2, characterized in that the safety determination unit determines the safety of the apparatus based on the learned model and the aperture image captured by the aperture imaging unit.

6. The system has a pre-trained model (54a) that has been trained in advance to recognize objects using camera images of the object to be inspected, The X-ray inspection apparatus according to claim 1 or 2, characterized in that the safety determination unit determines the safety of the apparatus based on the learned model and the aperture image captured by the aperture imaging unit.

7. The image feature recognition unit has a human body detection function that recognizes, based on the aperture image, that a part of a human body has been inserted into a predetermined imaging area including the aperture. When the safety determination unit detects that a part of the human body has been inserted into the predetermined imaging area using the human body detection function of the image feature recognition unit, it determines the safety of the device based on the detection information from the human body detection function. The X-ray inspection apparatus according to claim 1 or 2, further comprising an inspection control unit (30) that, when the human body detection function detects that a part of the human body has been inserted into the predetermined imaging area, stops the X-ray irradiation in the X-ray imaging unit and the transport drive of the conveyor, and outputs error information related to the X-ray inspection.

8. The system further includes a still image storage unit (53a) that stores still images obtained from camera footage, The image feature recognition unit performs image processing based on the still image stored in the still image storage unit to recognize classifiable morphological features related to the occlusion state of the opening and the detection information by the human body detection function as predetermined image feature quantities. The X-ray inspection apparatus according to claim 7, characterized in that the safety determination unit determines the safety of the shielding state of the opening that appears in the opening image and the detection information by the human body detection function.

9. An X-ray inspection apparatus (100) comprising: a housing (25) having at least one opening (25c, 25e) through which an object to be inspected (PF) being transported in a predetermined direction by a conveyor passes; an X-ray imaging unit that images the object to be inspected with X-rays within the housing; an image processing unit that inspects the quality of the object to be inspected based on the X-ray image (Dpx) from the X-ray imaging unit; and a shielding curtain disposed in the opening; An aperture imaging camera (151, 152) is provided independently outside the X-ray inspection apparatus to capture a predetermined imaging area (R1, R2) including the opening and output it as an aperture image (Dg1, Dg2) when at least the object to be inspected does not pass through the opening. Image feature recognition units (154, 155) recognize classifiable morphological features relating to the occlusion state of the aperture that appear in the aperture image from the aperture imaging camera as predetermined image feature quantities (fr1, fr2), An X-ray inspection system comprising: a safety determination unit (156) that determines the safety of the shielding function of the opening by the shielding curtain based on the predetermined image feature quantity recognized by the image feature recognition unit.

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