X-ray inspection equipment

Abstract

This invention provides an X-ray inspection apparatus that can reduce the chances of overlooking defects in articles. [Solution] The X-ray inspection apparatus of the present invention comprises a conveyor 12, an X-ray irradiator 13, an X-ray line sensor 14, and a controller 20. The controller 20 compares a first feature quantity and a second feature quantity and determines whether the X-ray irradiator 13 or the X-ray line sensor 14 is functioning normally based on the comparison result. The first feature quantity is calculated based on the X-ray detection value or the X-ray inspection image created from the X-ray detection value for each of the multiple articles transported by the conveyor 12 during a predetermined first period after the X-ray irradiator 13 starts irradiating X-rays. The second feature quantity is calculated based on the X-ray detection value or the X-ray inspection image created from the X-ray detection value for each of the multiple articles transported by the conveyor 12 during a second period, which is a period after the first period.

Description

Technical Field

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

Background Art

[0002] As a device for inspecting the presence or absence of defects such as foreign matter混入 in an article, an X-ray inspection apparatus is widely used. In an X-ray inspection apparatus, due to abnormalities such as deterioration of the inspection apparatus, it may be possible to overlook a defect in the article. Therefore, in an X-ray inspection apparatus, it is desired to reduce the overlooking of defects in the article.

[0003] Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-308600) describes an X-ray inspection apparatus capable of predicting the deterioration of an inspection apparatus. In the X-ray inspection apparatus of Patent Document 1, the deterioration of the X-ray inspection apparatus is predicted by determining the amount of decrease from the initial value of the output of the sensor.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, there is a possibility that an abnormality occurring during production may not be detected.

[0005] An object of the present invention is to provide an X-ray inspection apparatus capable of reducing the overlooking of defects in an article.

Means for Solving the Problems

[0006] The X-ray inspection apparatus of the first aspect comprises a transport unit, an X-ray irradiation unit, an X-ray detection unit, and a control unit. The transport unit transports articles. The X-ray irradiation unit irradiates the articles transported by the transport unit with X-rays. The X-ray detection unit detects X-rays. The control unit inspects the quality of the articles based on the detected X-ray values ​​detected by the X-ray detection unit. The control unit compares a first characteristic quantity and a second characteristic quantity and determines whether the X-ray irradiation unit or the X-ray detection unit is functioning correctly based on the comparison result. The first characteristic quantity is calculated based on the detected X-ray values ​​for multiple articles transported by the transport unit or an X-ray inspection image created from the detected X-ray values ​​during a predetermined first period after the X-ray irradiation unit starts irradiating X-rays. The second characteristic quantity is calculated based on the detected X-ray values ​​for each of the multiple articles transported by the transport unit or an X-ray inspection image created from the detected X-ray values ​​during a second period, which is a period following the first period.

[0007] This X-ray inspection system can reduce the chances of overlooking defects in goods.

[0008] The X-ray inspection apparatus of the second perspective is the same as the X-ray inspection apparatus of the first perspective, in which the first feature quantity is calculated using multiple items whose pass / fail inspection results are known. The second feature quantity is calculated using multiple items whose pass / fail inspection results are unknown.

[0009] The X-ray inspection apparatus of the third perspective is the same as the X-ray inspection apparatus of the first perspective, and the first and second feature quantities are calculated using multiple items whose pass / fail inspection results are unknown.

[0010] The X-ray inspection apparatus of the fourth perspective is an X-ray inspection apparatus of the first to third perspectives, and the group of items used for calculating the second feature quantity is transported continuously after the group of items used for calculating the first feature quantity.

[0011] The X-ray inspection apparatus of the fifth perspective is an X-ray inspection apparatus of any of the first to fourth perspectives, and the control unit uses the mean or standard deviation calculated from the detected values ​​as the first and second feature quantities.

[0012] The sixth X-ray inspection device is an X-ray inspection device of any of the first to fifth viewpoints, and the control unit sets a predetermined range for the second feature quantity relative to the value calculated from the first feature quantity, and determines that there is an abnormality if it falls outside the predetermined range.

[0013] The X-ray inspection apparatus of the seventh perspective is an X-ray inspection apparatus of any of the first to sixth perspectives, and the control unit further comprises a notification unit. The notification unit notifies when it determines that there is an abnormality in the X-ray irradiation unit or the X-ray detection unit.

[0014] The X-ray inspection apparatus of the eighth perspective is an X-ray inspection apparatus of any of the first to seventh perspectives, wherein the control unit detects multiple elements at different detection levels. Each of the first and second feature quantities includes multiple elements at different detection levels.

[0015] The X-ray inspection apparatus of the ninth perspective is the same as the X-ray inspection apparatus of the eighth perspective, and the detection level is changed depending on the element to be detected.

[0016] The X-ray inspection apparatus for the tenth viewpoint is an X-ray inspection apparatus for the eighth or ninth viewpoint, in which the first and second feature quantities are calculated using at least some of the elements among a plurality of elements. [Effects of the Invention]

[0017] This invention can reduce the chances of overlooking defects in articles. [Brief explanation of the drawing]

[0018] [Figure 1] This is an external perspective view of an X-ray inspection apparatus according to one embodiment of the present invention. [Figure 2] This is a diagram showing the process configuration before and after the X-ray inspection equipment. [Figure 3] This is an internal diagram of the shield box for an X-ray inspection device. [Figure 4] This is a schematic diagram illustrating the principle of X-ray inspection. [Figure 5] This is a block diagram of the controller. [Figure 6]It is a schematic diagram showing a group of articles. [Figure 7] It is a front view of the monitor screen in a normal X-ray inspection apparatus. [Figure 8] It is an operation flowchart of the abnormality detection unit. [Figure 9] It is a front view of the monitor screen in an abnormal X-ray inspection apparatus. [Figure 10] It is a front view of the monitor screen in another abnormal X-ray inspection apparatus. [Figure 11] It is a diagram showing an example of a detection value.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same reference numerals are given to the same elements, and duplicate descriptions are omitted.

[0020] (1) Configuration of the entire X-ray inspection apparatus 10 FIG. 1 is an external perspective view of an X-ray inspection apparatus 10 according to an embodiment of the present invention. Further, FIG. 2 is a front and rear process configuration diagram of the X-ray inspection apparatus 10. In FIGS. 1 and 2, the X-ray inspection apparatus 10 is incorporated into a production line of an article G such as food and performs quality inspection of the article G. Further, the X-ray inspection apparatus 10 irradiates the continuously conveyed article G with X-rays to determine whether the article G is good or bad.

[0021] The article G that is the inspection object is conveyed to the X-ray inspection apparatus 10 by the upstream conveyor 60. The article G is classified into good products or defective products in the X-ray inspection apparatus 10. The inspection result in the X-ray inspection apparatus 10 is sent to a sorting mechanism 70 arranged on the downstream side of the X-ray inspection apparatus 10.

[0022] The sorting mechanism 70 sends the article G determined to be a good product in the X-ray inspection apparatus 10 to a conveyor 80 that discharges good products, and sorts the article G determined to be a defective product in the X-ray inspection apparatus 10 in the defective discharge directions 90, 91. [[ID=3,9]]

[0023] (2) Detailed configuration Figure 3 is an internal configuration diagram of the shield box 11 of the X-ray inspection apparatus 10. In Figures 1 and 3, the X-ray inspection apparatus 10 consists of a shield box 11, a conveyor 12 (an example of a transport unit), an X-ray irradiator 13 (an example of an X-ray irradiation unit), an X-ray line sensor 14 (an example of an X-ray detection unit), a monitor 30 with touch panel functionality, and a controller 20 (an example of a control unit) (see Figure 5).

[0024] (2-1) Shield box 11 Openings 11a are formed on both sides of the shield box 11 to allow articles G to be moved in and out of the shield box 11. The openings 11a are covered by shielding curtains 11b to prevent X-ray leakage to the outside of the shield box 11. The shielding curtains 11b are molded from lead-containing rubber and are pushed aside by the articles G as they pass through the openings 11a.

[0025] The shield box 11 houses the conveyor 12, the X-ray irradiator 13, the X-ray line sensor 14, and the controller 20 (see Figure 5). The upper front of the shield box 11 also features a monitor 30, a key slot, and a power switch.

[0026] (2-2) Conveyor 12 The conveyor 12 transports the articles G inside the shield box 11. As shown in Figure 1, the conveyor 12 is positioned to pass through openings 11a formed on both sides of the shield box 11. The conveyor 12 then transports the articles G placed on the belt by rotating an endless belt with drive rollers driven by a conveyor motor 12a (see Figure 5).

[0027] The conveying speed of the conveyor 12 is precisely controlled by the inverter control of the conveyor motor 12a via the controller 20 so that it matches the set speed entered by the operator. The conveyor motor 12a is also equipped with an encoder 12b (see Figure 5) that detects the conveying speed of the conveyor 12 and sends the information to the controller 20.

[0028] (2-3)X-ray irradiator 13 As shown in Figure 3, the X-ray irradiator 13 is positioned above the conveyor belt 12. The X-ray irradiator 13 irradiates X-rays onto the items G being transported by the conveyor belt 12. The X-ray irradiator 13 irradiates X-rays into a fan-shaped irradiation range Rx toward the X-ray line sensor 14 below.

[0029] (2-4) X-ray line sensor 14 Figure 4 is a schematic diagram illustrating the principle of X-ray inspection. In Figure 4, the X-ray line sensor 14 is positioned below the conveyor belt 12. The X-ray line sensor 14 is mainly composed of a large number of pixel sensors 14a. These pixel sensors 14a are arranged horizontally in a straight line perpendicular to the direction of transport by the conveyor belt 12. Each pixel sensor 14a detects X-rays transmitted through the object G or the conveyor belt 12 and outputs an X-ray transmission signal. The X-ray transmission signal indicates the brightness of the X-rays.

[0030] (2-5) Monitor 30 Monitor 30 is a full-dot liquid crystal display that shows a screen prompting the operator to input the necessary judgment unit, filter, and parameter threshold values ​​required during inspection. Monitor 30 also has a touch panel function to accept input from the operator.

[0031] The monitor 30 displays a message on its screen when the controller 20 detects an abnormality in the X-ray inspection device 10.

[0032] (2-6) Controller 20 Figure 5 is a block diagram of the controller 20. In Figure 5, the controller 20 is equipped with a CPU (Central Processing Unit) 21, ROM (Read-Only Memory) 22, RAM (Random Access Memory) 23, HDD (Hard Disk Drive) 25, and a drive 24 for inserting storage media.

[0033] The CPU 21 executes various programs stored in the ROM 22 and HDD 25. The HDD 25 also stores inspection results. Inspection conditions and items can be set and changed by the operator using the touch panel function on the monitor 30. The operator can configure the system to store this data not only on the HDD 25 but also on the storage media inserted in the drive 24.

[0034] The controller 20 is also connected to the conveyor motor 12a, encoder 12b, X-ray irradiator 13, X-ray line sensor 14, and photoelectric sensor 15. The photoelectric sensor 15 is a synchronization sensor for detecting the timing when the object G to be inspected passes through the fan-shaped X-ray irradiation range Rx (see Figure 3).

[0035] The controller 20 inspects the quality of item G based on the detected X-ray values ​​obtained by the X-ray line sensor 14.

[0036] (3) Configuration of CPU21 The HDD 25 of the controller 20 stores inspection programs, including an image generation module and a foreign object inspection module. The CPU 21 of the controller 20 then reads and executes these program modules, thereby operating as the image generation unit 21a and the foreign object inspection unit 21b.

[0037] The HDD 25 of the controller 20 also stores an anomaly detection program, which includes a feature detection module, an anomaly detection module, and an anomaly notification module. The CPU 21 of the controller 20 then reads and executes these program modules, thereby operating as the feature detection unit 21c, the anomaly detection unit 21d, and the anomaly notification unit 21e.

[0038] (3-1) Image generation section 21a The image generation unit 21a generates an X-ray inspection image of the object G based on the X-ray transmission signal output from the X-ray line sensor 14. The image generation unit 21a acquires X-ray transmission signals output from each pixel sensor 14a of the X-ray line sensor 14 at fine time intervals as the object G passes through the fan-shaped X-ray irradiation range Rx (see Figure 3). The image generation unit 21a generates an X-ray inspection image of the object G based on the acquired X-ray transmission signals. The timing of when the object G passes through the fan-shaped X-ray irradiation range Rx is determined by the signal from the photoelectric sensor 15. The image generation unit 21a generates an X-ray inspection image of the object G by concatenating the data on the brightness of the X-rays obtained from each pixel sensor 14a of the X-ray line sensor 14 in a matrix in a time series.

[0039] Furthermore, the image generation unit 21a has an edge processing function that emphasizes spatial changes in brightness in the X-ray inspection image as contours in order to identify contours. In other words, by detecting areas (edges) in the X-ray inspection image where brightness changes sharply, the boundary between object G and other objects (contour of object G) can be detected.

[0040] (3-2) Foreign object inspection department 21b The foreign object inspection unit 21b detects foreign objects contained in the item G by performing a binarization process on the X-ray inspection image of the item G generated by the image generation unit 21a.

[0041] Specifically, a predetermined threshold is compared with the grayscale value of each pixel constituting the X-ray inspection image to determine whether the grayscale value of each pixel constituting the X-ray inspection image is less than or equal to the predetermined threshold. Here, the predetermined threshold includes a threshold for distinguishing between the background and non-background areas, and thresholds for distinguishing between item G and areas other than item G.

[0042] The X-ray inspection image is filtered so that, of all the pixels that make up the X-ray inspection image, pixels whose transmitted X-ray brightness (intensity) exceeds a predetermined threshold are represented by a shade corresponding to white, for example, and pixels below the predetermined threshold are represented by a shade corresponding to black, for example.

[0043] If an area appears darker than a predetermined threshold on the X-ray inspection image of item G, it is determined that item G contains foreign matter, and the item G is judged to be abnormal.

[0044] (3-3) Feature detection unit 21c The feature detection unit 21c calculates a first feature quantity based on X-ray detection values ​​or X-ray inspection images created from X-ray detection values ​​for multiple items G transported by the conveyor 12 during a predetermined first period.

[0045] The predetermined first period is any period from when the X-ray irradiator 13 starts irradiating with X-rays until immediately before irradiating the article GT which is the predetermined foreign object inspection target. The predetermined first period is, for example, the period during which the group of articles G1 that is transported before the article GT which is the predetermined foreign object inspection target is irradiated with X-rays, as shown in Figure 6. Here, the group of articles G1 is a collection of multiple articles G. The group of articles G1 may be the group of articles immediately preceding the article GT which is the predetermined foreign object inspection target. Alternatively, there may be other articles G or groups of articles between the group of articles G1 and the article GT which is the predetermined foreign object inspection target.

[0046] The first feature quantity is calculated using multiple items G whose quality inspection results are known. More specifically, the first feature quantity is calculated using multiple items G that were judged to be good products in the foreign object inspection. The number of items G used to calculate the first feature quantity is, for example, 100. For example, the feature quantity detection unit 21c calculates the first feature quantity using only 100 items G that were judged to be good products from the group of items G1 immediately preceding the item GT that is the predetermined foreign object inspection target.

[0047] The feature detection unit 21c uses, as a first feature, the mean, standard deviation, and / or moving mean calculated from the detected values ​​obtained for multiple items G judged to be good products, although this is not limited to these first features. The feature detection unit 21c may also calculate a reference statistic by further statistically processing the multiple moving mean values ​​that it has calculated. The feature detection unit 21c stores the calculated mean, standard deviation, moving mean, and / or reference statistic as data in a storage device such as an HDD 25.

[0048] As shown in Figure 7, the feature detection unit 21c detects multiple elements at different detection levels. The detection level is changed depending on the element to be detected. The elements are, for example, foreign objects, cavities, and air bubbles. In the case of foreign objects, the elements are, for example, metal or bone fragments.

[0049] The first feature quantity includes multiple elements with different detection levels. The first feature quantity is calculated using at least some of the multiple elements. The elements used as the first feature quantity can be selected by the operator of the X-ray inspection device. For example, if detection level 1 detects a metallic foreign object, the feature quantity detection unit 21c may calculate the first feature quantity for the metallic object using only detection level 1. Furthermore, if detection level 2 detects a bone fragment foreign object, the feature quantity detection unit 21c may calculate the first feature quantity for the bone fragment using only detection level 2. Alternatively, the feature quantity detection unit 21c may calculate the first feature quantity for both metallic and bone fragments using both detection level 1 and detection level 2. However, when multiple detection levels are used, the feature quantity detection unit 21c calculates the first feature quantity individually using the values ​​at each detection level.

[0050] The feature detection unit 21c calculates a second feature quantity in the second period, which is the period following the first period, based on the X-ray detection value or the X-ray inspection image created from the X-ray detection value for each of the multiple items G transported by the conveyor 12.

[0051] The second period, as shown in Figure 6, is the period after the first period during which the group of items G2, which includes the item GT to be inspected for foreign matter, is irradiated with X-rays. Here, the group of items G2 is a collection of multiple items G. The group of items G2 used for calculating the second feature quantity may be transported consecutively after the group of items G1 used for calculating the first feature quantity. Alternatively, another item G or group of items may exist between the group of items G1 and the group of items G2.

[0052] The second feature is calculated using multiple items G whose pass / fail inspection results are unknown. For example, 100 items G are used for the second feature.

[0053] The feature detection unit 21c uses, but is not limited to, the mean, standard deviation, and / or moving mean calculated from the detected values ​​obtained for multiple items G within the item group G2 as the second feature. The feature detection unit 21c may also calculate a reference statistic by further statistically processing the multiple moving mean values ​​that it has calculated. The feature detection unit 21c stores the calculated mean, standard deviation, moving mean, and / or reference statistic as data in a storage device such as an HDD 25.

[0054] The second feature quantity includes multiple elements with different detection levels. The second feature quantity is calculated using at least some of the multiple elements. The elements used as the second feature quantity can be selected by the operator of the X-ray inspection device. For example, if detection level 1 detects a metallic foreign object, the feature quantity detection unit 21c may calculate the second feature quantity for the metallic object using only detection level 1. Furthermore, if detection level 2 detects a bone fragment foreign object, the feature quantity detection unit 21c may calculate the second feature quantity for the bone fragment using only detection level 2. Alternatively, the feature quantity detection unit 21c may calculate the second feature quantity for both metallic and bone fragments using both detection level 1 and detection level 2. However, when multiple detection levels are used, the feature quantity detection unit 21c calculates the second feature quantity individually using the values ​​at each detection level.

[0055] (3-4) Anomaly detection unit 21d The anomaly detection unit 21d compares the first feature quantity calculated by the feature quantity detection unit 21c with the second feature quantity, and determines whether the X-ray irradiator 13 is functioning normally based on the comparison result.

[0056] The anomaly detection unit 21d sets a predetermined range for the second feature quantity relative to the numerical value calculated from the first feature quantity. The predetermined range is stored in the memory unit as an acceptable range that includes the normal value and values ​​close to the normal value. The normal value is the first feature quantity calculated from the detected values ​​obtained for 100 items judged to be good products. The upper and lower limits of the acceptable range are, for example, the first feature quantity ± standard deviation calculated from the detected values ​​obtained for 100 items judged to be good products. Alternatively, the upper and lower limits of the acceptable range can be predetermined based on, for example, the upper and lower limits of the range of detected values ​​that are acceptable for judging item G as a good product, in other words, the upper and lower limits of the acceptable range of detected values. The process of determining whether the detected value is within the acceptable range corresponds to the process of understanding the deviation of the detected value.

[0057] The anomaly detection unit 21d determines an anomaly when the second feature falls outside a predetermined range. A case where the second feature falls outside a predetermined range is, for example, when the standard deviation of the second feature is greater than the predetermined range (the test values ​​are scattered), or when the standard deviation of the second feature is smaller than the predetermined range (the test values ​​are not scattered). Alternatively, a case where the second feature falls outside a predetermined range is when the moving average value of the second feature is not within the predetermined range (the test values ​​are gradually decreasing or increasing).

[0058] The anomaly detection unit 21d compares the values ​​of multiple detection levels to determine whether the second feature quantity at each detection level exceeds a predetermined range calculated from the first feature quantity. For example, at detection level 1, which detects metal (example), the anomaly detection unit 21d compares the first feature quantity calculated using the values ​​of detection level 1 with the second feature quantity calculated using the values ​​of detection level 1. Furthermore, at detection level 2, which detects bone fragments (example), the anomaly detection unit 21d compares the first feature quantity calculated using the values ​​of detection level 2 with the second feature quantity calculated using the values ​​of detection level 2. Similarly, the anomaly detection unit 21d compares the first feature quantity with the second feature quantity at all detection levels or at selected detection levels. If the second feature quantity falls outside the predetermined range at any detection level, the anomaly detection unit 21d determines that an anomaly has occurred.

[0059] (3-5) Anomaly notification unit 21e The abnormality notification unit 21e notifies if it determines that the X-ray irradiator 13 is malfunctioning. The notification method is not particularly limited, but for example, the abnormality notification unit 21e displays on the monitor 30 that an abnormality has occurred.

[0060] (4) Method for detecting abnormalities in the X-ray inspection device 10 This section describes the method for detecting abnormalities in the X-ray inspection device 10. Figure 8 is a flowchart of the controller 20's operation when an abnormality is detected in the X-ray inspection device 10.

[0061] (4-1) Step S1 In Figure 9, in step S1, the feature detection unit 21c calculates a first feature based on the X-ray detection values ​​or X-ray inspection images created from the X-ray detection values ​​for multiple items G transported by the conveyor 12 during a predetermined first period.

[0062] (4-2) Step S2 In step S2, the feature detection unit 21c calculates a second feature based on the X-ray detection values ​​or X-ray inspection images created from the X-ray detection values ​​for each of the multiple items G transported by the conveyor 12 during the second period, which is the period following the first period.

[0063] (4-3) Step S3 In step S3, the anomaly detection unit 21d compares the first feature quantity with the second feature quantity and determines whether the X-ray irradiator 13 is functioning normally based on the comparison result.

[0064] The anomaly detection unit 21d determines that the X-ray irradiator 13 is abnormal when the second characteristic quantity falls outside a predetermined range.

[0065] (4-4) Step S4 If the abnormality detection unit 21d determines that an abnormality has occurred, the abnormality notification unit 21e displays a message on the monitor 30 indicating that an abnormality has occurred. Accordingly, the operator stops the X-ray inspection device 10.

[0066] (5) Characteristics (5-1) Under normal conditions, the X-ray inspection device 10 generates an X-ray inspection image of item G as shown in Figure 7 and detects foreign matter F contained in item G. However, abnormalities such as deterioration of the inspection device may occur in the X-ray inspection device 10. Deterioration of the inspection device is, for example, deterioration of the X-ray irradiator 13. When abnormalities such as deterioration of the inspection device occur, X-ray inspection images like those shown in Figures 9 and 10 are generated. Figure 9 shows an example where the X-ray inspection image is too dark. In cases like Figure 9, false detection of foreign matter may occur. Figure 10 shows an example where the X-ray inspection image is too bright. In cases like Figure 10, the abnormality detection unit 21d has difficulty detecting foreign matter. When such abnormalities occur, productivity may decrease or defects in the product may be overlooked.

[0067] Figure 11 shows an example of the normal detection value and the abnormal detection value at a certain detection level. In Figure 11, the solid line shows the normal detection value. In Figure 11, the dashed line shows the abnormal detection value when the X-ray inspection image is too bright. When an abnormality occurs in the X-ray inspection device 10, the detection value becomes smaller and the variation also decreases. Therefore, the abnormality detection unit 21d becomes less able to detect foreign objects.

[0068] Therefore, one method is to inspect the X-ray inspection device for abnormalities using test pieces before production begins (before transporting goods G for shipment begins). Another method is to predict the deterioration of the X-ray inspection device by determining the amount of decrease from the initial value of the sensor output. However, with these methods, there is a possibility of missing defects in goods if an abnormality occurs during production (while transporting goods G for shipment).

[0069] In this embodiment, the X-ray inspection device 10 compares a first feature quantity with a second feature quantity. Based on the comparison result, the X-ray inspection device 10 determines whether the X-ray irradiator 13 is functioning correctly. The first feature quantity is calculated based on the X-ray detection values ​​or X-ray inspection images created from the X-ray detection values ​​for multiple items transported by the conveyor 12 during a predetermined first period after the X-ray irradiator 13 starts irradiating X-rays. The second feature quantity is calculated based on the X-ray detection values ​​or X-ray inspection images created from the X-ray detection values ​​for each of the multiple items transported by the conveyor 12 during a second period, which is a period following the first period.

[0070] This X-ray inspection device determines abnormalities in the X-ray inspection device 10 by comparing the detected values ​​for multiple items G that are transported before the item GT that is the designated foreign object inspection target during production (while transporting items G for shipment), with the detected values ​​for multiple items G that include the item GT that is the designated foreign object inspection target. Therefore, abnormalities in the X-ray inspection device 10 can be detected even during production (while transporting items G for shipment). As a result, this X-ray inspection device 10 can reduce the chances of missing defective items.

[0071] (5-2) The first feature is calculated using multiple items G whose pass / fail inspection results are known. The second feature is calculated using multiple items G whose pass / fail inspection results are unknown.

[0072] This X-ray inspection device can detect abnormalities in the X-ray inspection device 10 even during production (while transporting goods G for shipment).

[0073] (5-3) The group of items G2 used to calculate the second feature is transported immediately after the group of items G1 used to calculate the first feature.

[0074] This X-ray inspection system can detect defects in the X-ray inspection system 10 during production without stopping production.

[0075] (5-4) The controller 20 uses the mean or standard deviation calculated from the detected values ​​as the first and second features.

[0076] In this X-ray inspection device 10, the first and second feature quantities can be compared using the mean or standard deviation calculated from the detected values.

[0077] (5-5) The controller 20 sets a predetermined range for the value of the second feature calculated from the first feature, and determines that there is an anomaly if the value falls outside the predetermined range.

[0078] This X-ray inspection device 10 allows for setting an acceptable range for whether or not the X-ray inspection device 10 is defective.

[0079] (5-6) The controller 20 further includes a notification unit that notifies the user if it determines that the X-ray irradiator 13 is malfunctioning.

[0080] This X-ray inspection device 10 can notify the operator of any defects in the X-ray inspection device 10.

[0081] (5-7) The controller 20 detects multiple elements at different detection levels. Each of the first and second features contains multiple elements at different detection levels.

[0082] This X-ray inspection device 10 can compare a first characteristic quantity and a second characteristic quantity for multiple foreign objects. Therefore, this X-ray inspection device 10 can accurately detect the presence or absence of defects.

[0083] (5-8) In this X-ray inspection device 10, the detection level is changed depending on the element being detected.

[0084] This X-ray inspection device 10 can detect different types of foreign objects. Therefore, this X-ray inspection device 10 can accurately detect the presence or absence of defects.

[0085] (5-9) The first and second features are calculated using at least some of the elements among multiple elements.

[0086] This X-ray inspection device 10 can detect defects by focusing on specific elements to be detected.

[0087] (6) Variant (6-1) Variation A In the above embodiment, the abnormality detection unit 21d compares the first feature quantity and the second feature quantity and determines whether the X-ray irradiator 13 is normal or not based on the comparison result. However, it is not limited to this. The abnormality detection unit 21d may also compare the first feature quantity and the second feature quantity and determine whether the X-ray line sensor 14 is normal or not based on the comparison result. In this modified example A, the abnormality detection unit 21d determines that the X-ray line sensor 14 is abnormal when the second feature quantity falls outside a predetermined range.

[0088] In this modified example A, the abnormality notification unit 21e notifies when it determines that the X-ray line sensor 14 is abnormal.

[0089] (6-2) Variation B In the above embodiment, if the abnormality detection unit 21d determines that an abnormality has occurred, the abnormality notification unit 21e displays a message on the monitor 30 indicating that an abnormality has occurred. Accordingly, the operator stops the X-ray inspection device 10. However, the embodiment is not limited to this.

[0090] If the abnormality detection unit 21d determines that there is an abnormality, the controller 20 may automatically stop the X-ray inspection device 10.

[0091] (6-3) Modification C The feature detection unit 21c calculates a first feature using multiple items G that are judged to be good products from the group of items G1 immediately preceding the item GT which is the predetermined item to be inspected for foreign matter, but is not limited to this.

[0092] The feature detection unit 21c may calculate the first feature quantity using multiple items G that have been determined to be good products before the start of production (before the items G for shipment are transported). In this case, the anomaly detection unit 21 may, if necessary, recall the first feature quantity that has been stored and compare it with the second feature quantity. In this modified example C, the frequency of anomaly detection can be reduced in the X-ray inspection device 10 in which anomalies occur relatively infrequently.

[0093] (6-4) Modification D In the above embodiment, the first feature quantity is calculated using a plurality of items G whose quality inspection results are known, and the second feature quantity is calculated using a plurality of items whose quality inspection results are unknown, but the embodiment is not limited to this.

[0094] Both the first and second feature quantities may be calculated using multiple items G whose pass / fail inspection results are unknown. In this modified example A, the anomaly detection unit 21 uses, for example, the frequency of defective products as the first and second feature quantities. In this modified example A, an anomaly in the X-ray inspection device can be detected for items G with a relatively high frequency of defective products.

[0095] (6-5) Modification E In the above embodiment, the feature detection unit 21c calculates the first feature and the second feature during continuous production. However, it is not limited to this.

[0096] The feature detection unit 21c may calculate the first feature and the second feature on different days. For example, the feature detection unit 21c may calculate the first feature at intervals such as every week or every month, and the memory unit may store it. In this case, the anomaly detection unit 21 may retrieve the stored first feature as needed and compare it with the second feature. In this modified example C, the frequency of anomaly detection can be reduced in the X-ray inspection device 10 where anomalies occur relatively infrequently. [Explanation of Symbols]

[0097] 10 X-ray inspection equipment 12. Conveyor (an example of an X-ray inspection device) 13. X-ray irradiator (an example of an X-ray irradiation unit) 14. X-ray line sensor (an example of an X-ray detection unit) 20. Controller (Example of a control unit) 26 Hochi Department G Goods G1 Goods Group G2 Goods Group [Prior art documents] [Patent Documents]

[0098] [Patent Document 1] Japanese Patent Publication No. 2005-308600

Claims

1. A conveying unit for transporting goods, An X-ray irradiation unit that irradiates the article being transported by the transport unit with X-rays, The X-ray detection unit that detects the aforementioned X-rays, A control unit that inspects the quality of the article based on the detected X-ray value detected by the X-ray detection unit, Equipped with, The control unit, A first feature quantity calculated based on the detected X-ray values ​​or X-ray inspection images created from the detected X-ray values ​​relating to a plurality of articles transported by the transport unit during a predetermined first period after the X-ray irradiation unit starts irradiating the X-rays, In the second period, which is the period following the first period, a second feature quantity calculated based on the detected X-ray values ​​or the X-ray inspection image created from the detected X-ray values ​​for each of the multiple articles transported by the transport unit, The X-ray irradiation unit or the X-ray detection unit is compared, and based on the comparison results, it is determined whether or not they are functioning normally. X-ray inspection equipment.

2. The first characteristic quantity is calculated using a plurality of the aforementioned articles whose quality inspection results are known. The second characteristic is calculated using a plurality of the aforementioned items whose quality inspection results are unknown. The X-ray inspection apparatus according to claim 1.

3. The first and second feature quantities are calculated using a plurality of the aforementioned articles whose quality inspection results are unknown. The X-ray inspection apparatus according to claim 1.

4. The group of articles used to calculate the second feature quantity is transported consecutively after the group of articles used to calculate the first feature quantity. The X-ray inspection apparatus according to claim 1.

5. The control unit uses the mean or standard deviation calculated from the detected value as the first feature quantity and the second feature quantity. The X-ray inspection apparatus according to claim 1.

6. The control unit sets a predetermined range for the second feature quantity relative to the value calculated from the first feature quantity, and determines that there is an abnormality if the value falls outside the predetermined range. The X-ray inspection apparatus according to claim 1.

7. The control unit further includes a notification unit that notifies when it determines that the X-ray irradiation unit or the X-ray detection unit is abnormal. The X-ray inspection apparatus according to claim 1.

8. The control unit detects multiple elements at different detection levels, Each of the first and second feature quantities includes a plurality of elements with different detection levels. The X-ray inspection apparatus according to claim 1.

9. The detection level is changed depending on the element to be detected. The X-ray inspection apparatus according to claim 8.

10. The first and second feature quantities are calculated using at least some of the elements among the plurality of elements. The X-ray inspection apparatus according to claim 8.

Images