X-ray inspection equipment

Abstract

To enable the center of gravity position G of a test object after inspection to be outputted in an X-ray inspection device 2a of a product W whose content Wb is packaged with a packaging material Wa.SOLUTION: An X-ray inspection device 2a extracts a content region Sb of a content in the X-ray image acquired by an X-ray generator 6 and an X-ray detector 7, calculates the center of gravity G from the content region, finds an origin O that represents a position in the X-ray image that serves as a point of reference from a prescribed position L1 in the width direction of a second conveyor 4 that is a previously set reference position condition, calculates the center of gravity position of the content relative to the origin, and outputs it to a robot 5. The robot is capable of attracting a test object at the position that corresponds to the center of gravity, so that it is possible to reliably move the test object.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an X-ray inspection device that inspects an object, the contents of which are packaged in packaging material, by transmitting X-rays while transporting the object, and more particularly to an X-ray inspection device that can calculate the position of the center of gravity of the object and output it to the outside. [Background technology]

[0002] The following Patent Document 1 discloses an invention related to an X-ray inspection device. This X-ray inspection device includes a conveyor 10, an X-ray inspection means 20, an opening / closing cover 32 that covers a conveying path 10a of a predetermined conveying section D2 downstream of the inspection area in the conveying direction, a sorting and discharging mechanism 40 that selectively discharges the inspected object out of the conveying path based on the inspection result of the inspection means, and a discharged object storage box 50 that stores the discharged inspected object W. The opening / closing cover 32 is a front-opening type that opens to the upper surface of the conveying path 10a of the predetermined conveying section D2 and its front side in the width direction when opened, and the sorting and discharging mechanism 40 is provided on the inner side of the opening / closing cover 32, and the discharged object storage box 50 is arranged on the rear side in the width direction of the conveying path 10a of the predetermined conveying section D2. According to this X-ray inspection device, there is no need to install a sorting device downstream of the conveying path cover near the X-ray inspection means, so that the device can be made compact and maintenance work from the front side can be facilitated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-033403 A Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional X-ray inspection devices such as that disclosed in Patent Document 1, moving means may be used to remove products determined to be defective from the transport path and transport inspected objects determined to pass to a predetermined assembly position. Known moving means include a sliding device that pushes products out of the transport path by the reciprocating motion of a mechanism, and a robot arm that holds products by chucking or suction and moves them to a desired position.

[0005] When moving a product using such a moving means, if the center of gravity of the product can be assumed to be at a fixed position based on its appearance, there is little possibility of problems occurring with the moving means. For example, when pushing the product out with a sliding device, the product can be moved reliably by pushing the center of gravity of the product. Also, when moving a product with a robot arm, the product can be held reliably by targeting the vicinity of the center of gravity, and the product held by the robot arm is unlikely to fall when being moved.

[0006] However, if the object to be inspected by the X-ray inspection device is a product whose contents are wrapped in a packaging material, problems may occur when moving the product using a moving means. In other words, products in which the position of the contents in the packaging material is not stable and the position of the contents is difficult to determine from the appearance of the product are likely to cause problems when moving the product using a moving means. For example, when pushing out the product using a sliding device, there is a possibility that the center of gravity of the product may not be pushed and the movement may fail. In addition, when moving the product using a robot arm, there is a possibility that the product may not be held because a part other than the center of gravity is targeted, or that the product may drop during movement even if it is held once.

[0007] The present invention has been made in consideration of the problems in the conventional technology described above, and has an object to enable, in an X-ray inspection device that inspects products whose contents are packaged in packaging material, to calculate and output the position of the center of gravity of an object after inspection in order to serve some technical purpose, such as ensuring reliable handling of the object after inspection. [Means for solving the problem]

[0008] The X-ray inspection apparatuses 2a, 2b, and 2c described in claim 1 are An X-ray inspection apparatus comprising: conveying means 3, 4 for conveying inspection objects W, W' each having a content Wb packed in a packaging material Wa; an X-ray generator 6 for irradiating X-rays onto the inspection objects W, W' conveyed by the conveying means 3, 4; and an X-ray detector 7 for detecting the X-rays transmitted through the inspection objects W, W', the X-ray inspection apparatus inspecting the inspection objects W, W' using X-ray images acquired from the X-rays detected by the X-ray detector 7, a content region extraction means 23 for extracting a content region Sb showing the content Wb on the X-ray image; A center of gravity calculation means 24 for calculating a center of gravity G of the content area; An origin O representing a reference position on the X-ray image is obtained from a preset reference position condition, the position of the center of gravity G relative to the origin O is calculated, and a robot arm 16 is controlled to move the inspected object W, W' to a destination according to the inspection result by contacting and holding the inspected object W, W' at the position of the center of gravity G. robot A center of gravity position output means 25 for outputting to the control unit 15; A control unit 20 including: Two sensors A and B are provided on the conveying means 3 and 4 to detect the downstream position of the object to be inspected. Equipped with death, The reference position condition is determined based on a predetermined position L1 in the width direction (Y) perpendicular to the conveying direction (X) of the conveying means 3 and 4 and the detection signals of the two sensors A and B. It is characterized by the fact that

[0009] An X-ray inspection apparatus according to claim 2. 2c The X-ray inspection apparatus according to claim 1 2c In the conveying means 3, 4 is composed of a first conveyor 3 for conveying the object to be inspected and acquiring the X-ray image, and a second conveyor 4 on which the robot arm 16 is provided; Of the two sensors A and B, one sensor B is provided on the downstream side of the X-ray detector 7 of the first conveyor 3 and outputs a detection signal to the control unit 20, and the other sensor A is provided on the second conveyor 4 and outputs a detection signal to the robot control unit 15. It is characterized by:

[0012] Claim 3 X-ray inspection equipment described in Place 2 c is claim 1 OR 2 X-ray inspection apparatus according to the present invention 2c In The present invention is characterized by having a reference position condition setting means 27 for setting the reference position condition. Effect of the Invention

[0013] According to the X-ray inspection device described in claim 1, The contents area of ​​the contents is extracted on the X-ray image, the center of gravity is calculated from the contents area, the origin representing the reference position on the X-ray image is obtained from preset reference position conditions, the center of gravity position of the contents relative to that origin is calculated, and this center of gravity position data (coordinates) is output to the control unit of a robot arm positioned downstream of the X-ray inspection device, which contacts and holds the position of the center of gravity, thereby moving the inspected object to a destination according to the inspection results, thereby ensuring reliable handling of the inspected object. Furthermore, the position of the most downstream edge in the outer region of the X-ray image can be detected based on the detection signal from sensor B provided on the conveying means 3, and can be set as the origin O in the X-direction. Therefore, even if the object to be inspected is an object with a large dimension in the X-ray irradiation direction, that is, an object with a relatively large height and with a relatively unclear outline in the X-ray image, the robot arm 16 can reliably handle the object by suctioning it at the center of gravity and securely holding it, moving it to the desired position for the boxing process without dropping it, or removing it from the conveying means 4.

[0014] According to the X-ray inspection device described in claim 2, The robot control unit 15 uses a predetermined position L1 in the width direction of the second conveyor 4, which is the basis for the set reference position condition in the Y direction, as a reference, and by matching the input timing of the detection signal of sensor B, which indicates the origin O in the X direction, with the input timing of the object to be inspected by sensor A, it can determine the center of gravity position of the object to be inspected as the movement destination of the suction device 17 of the robot arm 16.

[0017] Claim 3 According to the X-ray inspection device described in The reference position condition setting means makes it possible to easily set the data and instructions required to find the origin that represents the reference position on the X-ray image, so that the origin can be easily re-set even if there is a change, such as replacement or rearrangement, of a product handling device located downstream of the X-ray inspection device. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1A is a schematic structural diagram of an X-ray inspection device of the first embodiment, and FIG. 1B is a diagram showing the positional relationship between an X-ray image of an inspection object acquired by the X-ray inspection device and a set origin. [Diagram 2] 2 is a functional block diagram of a control unit of the X-ray inspection apparatus of the first embodiment. FIG. [Diagram 3]FIG. 13 is a schematic diagram showing the suction and movement operation of an object to be inspected by a robot provided downstream of the X-ray inspection apparatus of the first embodiment, in which (a) to (c) show cases where appropriate handling is performed after receiving center of gravity position data from the X-ray inspection apparatus of the first embodiment, and (d) and (e) show examples where a robot that does not receive center of gravity position data from the X-ray inspection apparatus fails to hold the object to be inspected. [Figure 4] FIG. 1A is a schematic structural diagram of an X-ray inspection device of the second embodiment, and FIG. 1B is a diagram showing an X-ray image of an object to be inspected acquired by the X-ray inspection device and a camera image of the object to be inspected taken by a camera set up in a subsequent stage. [Diagram 5] FIG. 11 is an explanatory diagram of a calculation in which a circumscribing circle (ellipse) is set on an acquired X-ray image of an object to be inspected and the center of the ellipse is set as the origin in the X-ray inspection apparatus of the second embodiment. [Figure 6] FIG. 13A is a schematic structural diagram of an X-ray inspection device of the third embodiment, and FIG. 13B is a diagram showing the positional relationship between an X-ray image of an inspection object acquired by the X-ray inspection device and a set origin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An X-ray inspection system according to a first embodiment will be described with reference to FIGS. As shown in FIG. 1(a), this X-ray inspection system 1a includes an X-ray inspection device 2a that inspects an object to be inspected W using X-rays while transporting the object to be inspected on a first conveyor 3, a second conveyor 4 as a transport means provided downstream of the X-ray inspection device 2a, and a robot 5 as a handling device provided downstream of the second conveyor 4 for moving the inspected object to be inspected W to a destination according to the inspection results.

[0020] The object W to be inspected by this X-ray inspection system 1a is characterized in that, as shown in the X-ray image of FIG. 1(b), the contents Wb are wrapped in a packaging material Wa, and the position of the contents Wb is difficult to determine from the appearance of the product. When such an object W to be inspected is moved by a robot 5, the position of the contents Wb in the packaging material Wa is unstable, and therefore, if a part other than the center of gravity G is targeted, it may fail to be held (see FIGS. 3(d) and (e)). Therefore, in the X-ray inspection device 2a of the first embodiment, in order to reliably handle the object W to be inspected by the robot 5 after inspection, the position of the center of gravity G of the inspected object W can be calculated and output to the robot 5.

[0021] As shown in FIG. 1(a), the X-ray inspection apparatus 2a includes a first conveyor 3 which is a transport means, an X-ray generator 6 which irradiates X-rays onto an object to be inspected W transported by the first conveyor 3, and an X-ray detector 7 which detects the X-rays which have passed through the object to be inspected W.

[0022] As shown in FIG. 1(a), the first conveyor 3 has a structure in which an endless conveyor belt 10 is wound around one driving roller 8 and three driven rollers 9. The first conveyor 3 receives the objects W to be inspected from a supply source (not shown) of the objects W to be inspected provided adjacent to the upstream end in FIG. 1(a). The first conveyor 3 transports the objects W to be inspected in a transport direction (also called the X direction) indicated by a horizontal rightward arrow in the figure. Note that the direction perpendicular to the transport direction in the horizontal plane and toward the back is called the width direction (also called the Y direction) of the conveyor belt 10. In FIG. 1(a), the width direction is the direction perpendicular to the paper surface on the surface of the conveyor belt 10, and is indicated by a circle with an X placed over it at the starting point of the arrow in the figure.

[0023] As shown in Fig. 1(a), the X-ray generator 6 is disposed with its radiation direction facing downwards, above the center of the first conveyor 3. The X-rays radiated from the X-ray generator 6 toward the conveyor belt 10 below are shown as straight dashed lines extending in the up-down direction within the plane of Fig. 1(a), but when viewed parallel to the conveying direction, that is, when viewed from the horizontal side in Fig. 1(a), they appear as a substantially triangular radiation surface with the X-ray generator 6 as its apex.

[0024] 1(a), the X-ray detector 7 is disposed so as to be in contact with the underside of the upper one of the endless transport belts 10 of the first conveyor 3, and to be located directly below the X-ray generator 6. The X-ray detector 7 has an X-ray line sensor 11 in which a large number of detection elements are arranged along the width direction (Y direction). The X-ray line sensor 11 detects X-rays and outputs X-ray transmission data, which is sent to a control unit 20 described later.

[0025] As shown in Fig. 1(a), a second conveyor 4 serving as a transport means is provided downstream of the X-ray inspection device 2a. The second conveyor 4 has a structure in which a transport belt 10 is wound around a drive roller 8 and a driven roller 9. The second conveyor 4 has the same transport surface height and transport direction as the first conveyor 3, and receives inspected objects W carried out by the first conveyor 3 and transports them downstream.

[0026] As shown in FIG. 1(a), a robot 5, which is a handling device for an object W to be inspected, is provided on one side of the downstream side of the second conveyor 4. This robot 5 has a robot control unit 15. The robot control unit 15 performs control operations using data indicating the position of the center of gravity G of the object W to be inspected, which is provided from the control unit 20 of the X-ray inspection device 2a, and a detection timing signal of the object W in the X direction, which is sent from a sensor A, which will be described later. The robot 5 also has a robot arm 16 controlled by the robot control unit 15, and grasping It has an adsorption device 17 as a means.

[0027] As shown in Fig. 1(a), a sensor A for detecting an object to be inspected W transported by the second conveyor 4 is provided on the side of the second conveyor 4 upstream of the robot 5. The sensor A is a transmission type having a light projector and a light receiver, and outputs a detection signal when the object to be inspected W enters between them. The detection signal of the sensor A is input to the robot control unit 15, and is used to control the operating position of the robot 5 so as to match with position data of the center of gravity G in the X direction sent from the control unit 20 of the X-ray inspection device 2a.

[0028] Although the details of the control will be described later, the robot 5 can hold the test object W by contacting the air suction port of the suction device 17 to the position of the center of gravity G of the test object W and suctioning the test object W, and can release the holding of the test object W by stopping the suction of air, so that the test object W held at the tip of the robot arm 16 can be reliably moved to a desired position by moving the robot arm 16. Note that, as the form of the gripping means provided at the tip of the robot arm 16, the suction device 17 that sucks and holds the test object W by sucking air is exemplified, but a clamping device that holds the test object W by pinching two sides of the test object W with a plurality of claw-like bodies, or a sliding movement device that contacts one side of the test object W and slides it can also be used, and the form of the gripping means is preferably selected taking into consideration the shape and weight of the test object W, the moving direction and moving distance, and the required moving speed, etc., and in any form, the action of the gripping means of the robot arm 16 in each form is controlled to be appropriately applied to the center of gravity G of the test object W.

[0029] The control unit 20 of the X-ray inspection apparatus 2a will be described with reference to FIGS. 1(a) and 2, the X-ray transmission data output from the X-ray line sensor 11 is input to the control unit 20 of the X-ray inspection apparatus 2a. As shown in Fig. 2, the X-ray transmission data of the inspection object W sent from the X-ray detector 7 is stored in the storage means 21 of the control unit 20. The storage means 21 stores, for example, several hundred pieces of X-ray transmission data corresponding to the number of detection elements per line (Y direction) of the X-ray detector 7, for at least a predetermined number of lines (for example, several hundred lines) corresponding to the length (length from the front end to the rear end) of the inspection object W being transported in the transport direction (X direction).

[0030] As shown in Fig. 2, the control unit 20 has an outline region extraction means 22. The outline region extraction means 22 creates an X-ray image of a predetermined size including the inspection object W, which has a density level corresponding to a gray value that becomes lighter as the amount of transmission increases, from the X-ray transmission data stored in the storage means 21. Fig. 1(b) is a schematic diagram of this X-ray image. The outline region extraction means 22 extracts a portion of this X-ray image having a density level equal to or higher than a specified threshold value as the outline region Sa of the packaging material Wa. In the X-ray image shown in Fig. 1(b), the inner portion of the packaging material Wa that forms the outline of the inspection object W is the outline region Sa.

[0031] In addition, the outer region extraction means 22 calculates a density histogram of the entire X-ray image created from the X-ray transmission data stored in the memory means 21, and separates and binarizes the data of the object to be inspected W from the data other than the object to be inspected W (the belt surface) from this density histogram.For example, in the overall density histogram, the data is binarized by setting the data of the object to be inspected W to 255 and the data other than the object to be inspected W to 0, and the data of the object to be inspected W from the binarized data can be extracted as the outer region Sa of the packaging material Wa.

[0032] As shown in Fig. 2, the control unit 20 has a content region extraction means 23. The content region extraction means 23 extracts a portion of the X-ray image within the outer region Sa that has a density level equal to or higher than a specified threshold as a content region Sb corresponding to the content Wb of the inspection object W. In the X-ray image shown in Fig. 1(b), the inner part of the content Wb inside the packaging material Wa of the inspection object W is the content region Sb.

[0033] The content area extraction means 23 may extract an X-ray image having a density level exceeding a predetermined threshold as a content area Sb corresponding to the content Wb of the inspection object W in parallel with the extraction process of the outer shape area Sa.

[0034] As shown in Fig. 2, the control unit 20 has a center of gravity calculation means 24 that calculates the center of gravity G. The center of gravity calculation means 24 calculates the center of gravity G of the content area Sb of the X-ray image. Specifically, in the X-ray image shown in Fig. 1(b), provisional center of gravity coordinates relative to a provisional origin are calculated for a plurality of pixels (not shown) that constitute the content area Sb. The coordinates of the provisional origin can be, for example, the minimum and maximum values ​​in the X and Y directions of the content area Sb in a coordinate system in which the lower left corner of the X-ray image is (0,0).

[0035] As shown in Fig. 2, the control unit 20 has a reference position condition setting means 27. The reference position condition setting means 27 sets a reference position condition for determining an origin O of coordinates that serves as a reference for data when calculating data on the position of the center of gravity G of the contents Wb of the inspection object W based on the center of gravity G calculated by the center of gravity calculation means 24 in the X-ray image shown in Fig. 1(b). Note that the reference position condition may be set to a fixed value inside the device when there is no change in the operation of the X-ray inspection system.

[0036] 1(b), in the X-ray inspection apparatus 2a of the first embodiment, a predetermined position L in the width direction of the second conveyor 4 that transports the inspection object W handled by the robot arm 16 is set to the position of the origin O in the Y direction. Specifically, the predetermined position L in the Y direction can be a position of one edge of the width direction of the transport belt 10, or a position of a guide plate (not shown) parallel to the transport direction that is provided along one edge of the width direction of the transport belt 10.

[0037] 1(b) is set as the reference position condition in the Y direction. The equipment such as the second conveyor 4 and the robot 5 arranged downstream of the X-ray inspection device 2a may be changed to other models as necessary, in which case the predetermined position L1 in the Y direction of the downstream equipment may also be changed. Therefore, it is convenient to make the numerical data indicating the predetermined position L1 inputtable as an arbitrary numerical value from the reference position condition setting means 27, rather than making it a fixed value.

[0038] 1(b), in the X-ray inspection apparatus 2a of the first embodiment, the corner on the downstream side in the X-direction of the outer region Sa of the inspection object W in the X-ray image is set as the reference position condition in the X-direction. The position of the origin O in the X-direction is automatically determined by the control unit 20 acquiring the X-ray image in accordance with this reference position condition.

[0039] As shown in FIG. 2, the control unit 20 has a center of gravity position output means 25 that calculates and outputs the position of the center of gravity G. The center of gravity position output means 25 obtains an origin O based on the reference position condition in the X direction and the reference position condition in the Y direction described above, and calculates the position of the center of gravity G of the content area Sb relative to the origin O from this origin O and the temporary origin and temporary center of gravity coordinates calculated by the center of gravity calculation means 24. Specifically, in the same coordinate system as the center of gravity calculation means 24, the distance between the predetermined position L1, which is the reference position condition in the Y direction, and the edge L2 is converted into the number of pixels to obtain the Y coordinate, and the corner on the most downstream side in the X direction is obtained as the X coordinate. Then, the obtained X coordinate and Y coordinate are set as the origin O, and the position of the center of gravity G is calculated by correcting the value of the temporary center of gravity coordinate for the amount of deviation in each direction between the origin O and the temporary origin. The calculated position data of the center of gravity G is output to the robot control unit 15.

[0040] 1(a), position data of the center of gravity G output by the control unit 20 of the X-ray inspection apparatus 2a is input to the robot control unit 15. A detection signal from a sensor A provided on the second conveyor 4 is also input to the robot control unit 15. The detection signal from the sensor A indicates that the position in the X direction of the origin O set by the control unit 20, i.e., the most downstream corner of the inspected part, has been detected by the sensor A on the second conveyor 4 upstream of the robot 5.

[0041] 2, the control unit 20 has a display unit 26. The display unit 26 can display information required for control, such as data and instructions input to the control unit 20, X-ray images acquired by the control unit 20, an origin O set in the control unit 20, and the position of the center of gravity G calculated based on the origin O.

[0042] According to the X-ray inspection system 1a configured as above, the following advantageous effects can be obtained. The object W to be inspected is conveyed by the first conveyor 3, and X-rays irradiated from the X-ray generator 6 pass through the object W to be detected by the X-ray detector 7. The control unit 20 of the X-ray inspection device 2a obtains an X-ray image as shown in FIG. 1(b) from the X-ray transmission data from the X-ray detector 7, and extracts the outer region Sa of the packaging material Wa and the content region Sb of the content Wb from this X-ray image. Furthermore, the control unit 20 calculates the center of gravity of the content region Sb, and determines an origin O representing a reference position on the X-ray image based on the reference position conditions input by the reference position condition setting means 27. The control unit 20 then calculates the center of gravity position of the content relative to this origin O, and outputs position data of the center of gravity G to the robot control unit 15.

[0043] The object W to be inspected that has passed through the X-ray inspection device 2a transfers to the second conveyor 4 and passes the sensor A. The robot control unit 15 determines the destination of the suction device 17 of the robot 5 so as to match the center of gravity position from the X-ray inspection device 2a by timing using a detection signal from the sensor A indicating the position of the origin O in the X-direction, based on a predetermined position L1 in the width direction of the second conveyor 4 that is the basis of the set reference position condition in the Y direction. This allows the robot 5 to reliably suction and hold the object W to be inspected at the center of gravity position, and reliably handle the object W, such as by moving the object W to a desired position for the boxing process without dropping it, or removing it from the second conveyor 4.

[0044] 3(a) to 3(c) are schematic diagrams showing the suction and movement of the inspection object W by the robot 5 in the first embodiment. As described above, the inspection object W targeted by this X-ray inspection system 1a is an object W in which contents Wb are wrapped in a packaging material Wa, and the position of the contents Wb is difficult to determine from the appearance of the product, but the robot 5, which acquires position data of the center of gravity G from the X-ray inspection device 2a, can suction the suction device 17 to a surface position corresponding to the center of gravity G of the inspection object W. Therefore, the suction is reliable and the inspection object W does not fall during movement, allowing proper handling.

[0045] 3(d) and (e) show a case where the X-ray inspection device 2a cannot output the position data of the center of gravity G, that is, a case where the movement of the object to be inspected W described in the related art is hindered. If the robot 5 cannot use the position data of the center of gravity G of the object to be inspected W, it becomes difficult for the robot 5 to adhere to the surface of the object to be inspected W at the position of the center of gravity G. Holding of the object to be inspected W by suction becomes unreliable, and the risk of the object to be inspected W dropping during movement increases.

[0046] In the first embodiment described above, the reference position condition in the Y direction is based on a predetermined position L1 in the width direction of the second conveyor 4, which is mechanically fixed, so that even if the X-ray image is not particularly clear, at least the origin O in the Y direction can be accurately determined. Therefore, good results can be expected regarding the calculation accuracy of the position of the center of gravity G of the inspection object W to be output.

[0047] An X-ray inspection system 1b of the second embodiment will be described with reference to Fig. 4, focusing on the parts that differ from the first embodiment. The same parts as in the first embodiment (Fig. 1) are denoted in Fig. 4 by the same reference numerals. For the same configurations, functions, and effects as the first embodiment, the description of the first embodiment and Fig. 2 are cited.

[0048] As shown in FIG. 4(a), in an X-ray inspection system 1b of the second embodiment, a camera 30 serving as an imaging means is provided facing downward above the upstream side of a robot 5 on a second conveyor 4 following an X-ray inspection device 2b. The sensor A of the first embodiment is not present in the second embodiment. The camera image output by the camera 30 is input to a robot control unit 15. The camera image is an image on an XY coordinate plane similar to the X-ray image acquired by an X-ray inspection device 2b.

[0049] According to the X-ray inspection apparatus 2b of the second embodiment, the outer region extraction means 22 of the control unit 20 determines the origin O based on the outer region Sa extracted from the X-ray image shown in Fig. 4(b). That is, by operating the reference position condition setting means 27 (see Fig. 2), a part of the outer region Sa of the X-ray image, for example, a part (the lowermost corner in this example) at a position that is the minimum value in the Y direction in the same coordinate system as the center of gravity calculation means 24 in the X-ray image of Fig. 4(b) can be set as the reference position condition. It is convenient to determine in advance which part of the X-ray image is to be the reference position condition in this way, but it may be set by the reference position condition setting means 27 each time according to the type of product.

[0050] According to the X-ray inspection apparatus 2b of the second embodiment, the center of gravity position output means 25 of the control unit 20 determines the origin O based on the set reference position condition, and calculates the position of the center of gravity G of the content area Sb of the X-ray image relative to the origin O from this origin and the virtual origin and virtual center of gravity coordinates calculated by the center of gravity calculation means 24, and outputs it to the robot control unit 15.

[0051] 4(b), the robot control unit 15 obtains an origin O2 for the camera image sent from the camera 30, which is located at the same position as the origin on the X-ray image based on the outer shape of the object W to be inspected, and determines the position of the center of gravity G2 in the camera image based on the origin O2, and determines this as the movement destination of the suction device 17 of the robot 5. The robot arm 16 is operated in accordance with the timing of acquisition of the camera image by the camera 30, and the suction device 17 is moved to the position of the center of gravity of the object W to be inspected. This allows the object W to be securely held by suction, and the object W to be moved to a desired position for the boxing process without dropping, or removed from the second conveyor 4, thereby enabling reliable handling of the object W.

[0052] FIG. 5 is a diagram showing a modified example of the method of setting the origin O in the X-ray inspection apparatus 2b of the second embodiment. In this modified example, the control unit 20 of the X-ray inspection apparatus 2b sets a circumscribing circle (ellipse) on the image of the inspection object W in the acquired X-ray image, and sets its center as the origin O. More specifically, in the image of the inspection object W shown in FIG. 5, an ellipse (circle) C passing through four vertices P1, P2, P3, and P4 of the outer shape area Sa, which is the maximum area, is drawn, and the intersection point between the major axis and the minor axis of the drawn ellipse (circle) C is calculated and set as the origin O. Although the content area Sb is not shown in the image of the inspection object W in FIG. 5, the center of gravity G of the content area Sb is calculated based on the set origin O and output to the robot control unit 15.

[0053] In the second embodiment (including the modified example) described above, the origin O is determined based on the outer shape of the object W in the X-ray image, so that favorable results can be obtained when the X-ray image is particularly clear. For example, when the object W is an article with a small dimension in the X-ray irradiation direction (i.e., a relatively small height), the spread of the X-rays transmitted through the object W becomes relatively small, and the contour of the X-ray image becomes relatively clear, so that favorable results can be expected in terms of the accuracy of calculation of the position of the center of gravity G of the contents of the object W in the X-ray image.

[0054] An X-ray inspection system 1c of the third embodiment will be described with reference to Fig. 6, focusing on the parts that differ from the first embodiment. The same parts as in the first embodiment (Fig. 1) are denoted in Fig. 6 by the same reference numerals. For the same configurations, functions, and effects as the first embodiment, the description of the first embodiment and Fig. 2 are cited.

[0055] The third embodiment shown in Fig. 6(a) differs from the first embodiment shown in Fig. 1 in terms of the feature relating to the shape of the object to be inspected W. The object to be inspected W' to which the third embodiment is applied is an article having a large dimension in the X-ray irradiation direction (i.e., a relatively large height). In the case of such an object to be inspected W', the spread of the X-rays transmitted through the object to be inspected W' becomes relatively large, and the contour of the X-ray image becomes blurred and relatively unclear. Therefore, when the origin O is set based on the X-ray image, there is a risk that the accuracy of the position of the center of gravity G of the object to be inspected W' calculated based on this may decrease.

[0056] The third embodiment shown in FIG. 6(a) differs from the first embodiment shown in FIG. 1 in that a sensor B is provided on the first conveyor 3 to set the origin O in the X direction due to the above-mentioned feature regarding the shape of the object W' to be inspected. That is, the first conveyor 3 is provided with a sensor B downstream of the X-ray detector 7 to detect the object W' to be inspected. This sensor B has the same configuration as the sensor A provided on the second conveyor 4, but the detection signal of the sensor B is input to the center of gravity position output means 25 (see FIG. 2) of the control unit 20 of the X-ray inspection device 2c and is used to obtain the X direction of the origin O. That is, as shown in FIG. 6(b), the detection signal of the sensor B detects the position of the most downstream edge in the outer region Sa of the X-ray image, and in the X-ray inspection device 2c of the third embodiment, this is set as the origin O in the X direction. That is, the position in the X direction corresponding to the input timing of the detection signal of the sensor B becomes the origin O in the X direction.

[0057] 6(b), in X-ray inspection apparatus 2c of the third embodiment, numerical data indicating the distance between a predetermined position L1 in the width direction of second conveyor 4 and an edge L2 parallel to the X direction of an X-ray image is used as the reference position condition in the Y direction. This is similar to the first embodiment described above, and the origin O in the Y direction is precisely determined.

[0058] According to the X-ray inspection system 1c of the third embodiment, the following advantageous effects can be obtained. The object W' to be inspected is conveyed by the first conveyor 3, and as in the first embodiment, the control unit 20 acquires an X-ray image and extracts the outer region of the packaging material Wa and the content region Sb of the content Wb from the X-ray image. Furthermore, the control unit 20 calculates the center of gravity of the content region Sb, and determines an origin O that represents a reference position on the X-ray image based on the reference position conditions input by the reference position condition setting means 27. The control unit 20 then calculates the position of the center of gravity of the content relative to the origin O, and outputs position data of the center of gravity G to the robot control unit 15.

[0059] The object W' that has passed the X-ray inspection device 2c transfers to the second conveyor 4 and passes the sensor A. The robot control unit 15 uses a predetermined position L1 in the width direction of the second conveyor 4, which is the basis of the set reference position condition in the Y direction, as a reference, and matches the input timing of the detection signal of the sensor B indicating the position of the origin O in the X direction with the input timing of the object W' by the sensor A to determine the center of gravity position from the X-ray inspection device 2c as the destination of the suction device 17 of the robot 5. This allows the robot 5 to reliably suction and hold the object W' at the center of gravity position, and reliably handle the object W', such as moving the object W' to a desired position for the packing process without dropping it, or removing it from the second conveyor 4.

[0060] As described above, according to the X-ray inspection device provided in the X-ray inspection system of the embodiment, the outer shape area of ​​the packaging material and the content area of ​​the content are extracted from the acquired X-ray image, the center of gravity is calculated from the content area, an origin O representing a reference position on the X-ray image is obtained from a preset reference position condition, and the center of gravity position of the content relative to the origin O can be calculated and output to the outside. The reference position condition for obtaining the origin O can be set based only on the outer shape area of ​​the X-ray image, or can be set using a predetermined position on the mechanism of the second conveyor 4 provided in the subsequent stage, or can be set by detecting a specific location corresponding to the outer shape area of ​​the X-ray image with the sensor B provided on the first conveyor 3. Such reference position conditions can be arbitrarily selected according to the characteristics of the object to be inspected. If the data on the center of gravity position output by the X-ray inspection device is used to control a product handling device provided in the subsequent stage of the X-ray inspection device, effects such as reliable movement and sorting of the object to be inspected can be obtained. [Explanation of symbols]

[0061] 1a, 1b, 1c...X-ray inspection system 2a, 2b, 2c...X-ray inspection equipment 3...First conveyor as a transport means 4...Second conveyor as a transport means 5. Robots as handling devices 6…X-ray generator 7…X-ray detector 15...Robot control unit 20...Control unit of X-ray inspection device 22...Outline area extraction means 23...Contents area extraction means 24…Center of gravity calculation means 25... Center of gravity position output means 27...Reference position condition setting means 30…Camera A…Sensor B…Sensor C: Ellipse that is the circumscribing circle of the outline area O…Origin G...Center of gravity W, W': Inspection object Wa...Packaging material Wb…Contents Sa: Outer shape area of ​​packaging material Sb: Content area of ​​contents L1: Predetermined position in the width direction of the conveying means

Claims

1. An X-ray inspection device comprising: conveying means (3, 4) for conveying an object to be inspected (W, W') in which contents (Wb) are packaged in a packaging material (Wa); an X-ray generator (6) for irradiating the object to be inspected conveyed by the conveying means with X-rays; and an X-ray detector (7) for detecting the X-rays transmitted through the object to be inspected, the X-ray inspection device inspecting the object to be inspected using an X-ray image acquired from the X-rays detected by the X-ray detector, a content area extraction means (23) for extracting a content area (Sb) showing the content on the X-ray image; A center of gravity calculation means (24) for calculating a center of gravity (G) of the content area; a center-of-gravity position output means (25) for determining an origin representing a reference position on the X-ray image from a preset reference position condition, calculating the position of the center of gravity relative to the origin, and outputting the calculated position to a robot control unit (15) for controlling a robot arm (16) for contacting and holding the position of the center of gravity to move the inspected object to a destination according to the inspection result; A control unit (20) including: two sensors (A, B) provided on the conveying means for detecting a most downstream position of the object to be inspected; The X-ray inspection device (2c) is characterized in that the reference position condition is determined based on a predetermined position (L1) in a width direction (Y) perpendicular to the conveying direction (X) of the conveying means and the detection signals of the two sensors.

2. The transport means (3, 4) comprises a first conveyor (3) for transporting the object to be inspected and acquiring the X-ray image, and a second conveyor (4) on which the robot arm (16) is provided; The X-ray inspection device (2c) according to claim 1, characterized in that of the two sensors (A, B), one sensor (B) is provided on the first conveyor downstream of the X-ray detector (7) and outputs a detection signal to the control unit (20), and the other sensor (A) is provided on the second conveyor and outputs a detection signal to the robot control unit (15).

3. 3. The X-ray inspection apparatus (2c) according to claim 1, further comprising a reference position condition setting means (27) for setting the reference position condition.

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