JP2013088143A - X-ray foreign matter detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray foreign matter detector capable of preventing deterioration in foreign matter detection performance by substantially matching the size and shape of an object to be inspected on two X-ray images obtained by an energy subtraction method.SOLUTION: An X-ray foreign matter detector comprises: a support construction 100 for supporting an X-ray tube 31 in a manner adjustable to a position of a conveyance direction upstream side or a conveyance direction downstream side of a conveyance unit 2 on a plane surface parallel to a conveyance surface; an adjustment determination unit 81 for obtaining a first waveform and a second waveform that indicate shading changes in a conveyance direction of an object W to be inspected from a first X-ray image data and a second X-ray image data and for determining an adjustment direction of the X-ray tube 31 on the basis of a difference between the shape of the first waveform and the shape of the second waveform; and a display device 5 for displaying an adjustment direction determined by the adjustment determination unit 81.

Description

  The present invention relates to an X-ray foreign object detection device that detects foreign substances mixed in an object to be inspected such as meat, fish, processed foods, and pharmaceuticals, and in particular, combines foreign images by synthesizing images from a plurality of X-ray line sensors. The present invention relates to an X-ray foreign matter detection apparatus that employs an energy subtraction method for obtaining an enhanced image.

  In general, an X-ray foreign object detection apparatus irradiates X-rays from X-ray generators on various types of inspection objects (for example, meat, fish, processed foods, pharmaceuticals, etc.) that are sequentially conveyed on a conveyance path at predetermined intervals. The inspection object is inspected for foreign substances such as metal, glass, stones, and bones, and a lack of the inspection object, based on the amount of transmitted X-rays.

  Conventionally, in this type of X-ray foreign object detection device, a low energy and a high energy X-ray image pair, that is, a dual energy X-ray image is acquired using X-ray sources having different tube voltages, and these two X-ray images are synthesized. By using the energy subtraction method, the influence of the thickness of the object to be inspected is reduced, and the contrast between the object to be inspected and the foreign object in the object is enhanced to obtain an image in which the foreign object is emphasized (see FIG. For example, see Patent Document 1).

JP 2010-91483 A

  However, in the conventional technique described in Patent Document 1, an X-ray image obtained by combining one X-ray source and an X-ray line sensor and an X-ray obtained by combining the other X-ray source and an X-ray line sensor. If the size and shape of the line images do not match and the position of the boundary between the objects to be inspected on the two X-ray images is shifted, the object to be inspected on the X-ray images is combined when the two X-ray images are combined. The position shift of the boundary is also emphasized by the high contrast, and there is a problem that the foreign object detection performance is greatly impaired.

  In this type of X-ray foreign object detection apparatus, the size of the X-ray image is determined by the three relative positions of the X-ray source, the conveyance surface of the object to be inspected, and the X-ray line sensor. The deviation occurs when the positional relationship between one X-ray source and the X-ray line sensor and the other X-ray source and the X-ray line sensor are shifted due to an assembly error or the like.

  Further, the size deviation of the X-ray image is as small as several pixels, and it is substantially impossible to match the size by enlarging or reducing the X-ray image by image processing because the information on the foreign matter also changes. Because it is possible, other methods have been sought.

  Therefore, the present invention has been made to solve the conventional problems as described above, and the size and shape of the object to be inspected on the two X-ray images obtained by the energy subtraction method are substantially matched, and the foreign object detection performance. An object of the present invention is to provide an X-ray foreign object detection device capable of preventing the decrease of the above.

  An X-ray foreign matter detection apparatus according to the present invention includes a transport unit that transports an inspection object on a transport surface, an X-ray source that irradiates the inspection object transported on the transport surface, and the transport surface. The first X-ray image data corresponding to the X-rays corresponding to the X-rays which are arranged at a position opposite to the X-ray source with the X-ray interposed therebetween, and which are irradiated from the X-ray source and transmitted through the inspection object, and the X-ray source. A first X-ray line sensor and a second X-ray line sensor that respectively output second X-ray image data corresponding to X-rays transmitted through the inspection object, and the first X-ray image data and the second X-ray image data The X-ray image data of the image and outputting as one image data corresponding to the inspection object, and the presence or absence of foreign matter in the inspection object based on the image data output from the image combining means An X-ray foreign object detection device comprising: A support means for supporting the X-ray source on a plane parallel to the transport plane so that the position of the X-ray source can be adjusted upstream or downstream in the transport direction of the transport means; the first X-ray image data; A first waveform and a second waveform indicating a change in density in the conveyance direction of the inspection object are respectively acquired from the second X-ray image data, and the difference between the first waveform shape and the second waveform shape is obtained. Based on the adjustment determination means for determining the adjustment direction of the X-ray source, and display means for displaying the adjustment direction determined by the adjustment determination means.

  With this configuration, since the display unit displays the adjustment direction of the X-ray source conveyance direction, the user adjusts the position of the X-ray source according to the displayed adjustment direction, so The size and shape of the inspection object can be substantially matched. Therefore, the size and shape of the object to be inspected on the two X-ray images obtained by the energy subtraction method can be substantially matched to prevent the foreign matter detection performance from being lowered.

  In the X-ray foreign object detection device according to the present invention, the second X-ray line sensor is disposed on the downstream side in the transport direction of the first X-ray line sensor, and the adjustment determination unit includes the first X-ray line sensor. When the width of the first waveform is longer than the width of the second waveform at a predetermined height of the waveform and the second waveform, the adjustment direction of the X-ray source is upstream in the transport direction It is characterized by determining.

  In the X-ray foreign object detection device according to the present invention, the second X-ray line sensor is disposed on the downstream side in the transport direction of the first X-ray line sensor, and the adjustment determination unit includes the first X-ray line sensor. When the angle of the upstream end point of the lower base of the trapezoid shape formed by the waveform is smaller than the angle of the downstream end point of the lower base of the trapezoid shape formed by the second waveform, the adjustment direction of the X-ray source is the transport It is characterized in that it is determined to be upstream in the direction.

  In the X-ray foreign object detection device according to the present invention, the second X-ray line sensor is disposed on the downstream side in the transport direction of the first X-ray line sensor, and the adjustment determination unit includes the first X-ray line sensor. When the length of the upstream side of the trapezoidal shape formed by the waveform is longer than the length of the downstream side of the trapezoidal shape formed by the second waveform, the adjustment direction of the X-ray source is upstream of the transport direction It is determined that it is.

  With this configuration, even when the first X-ray line sensor and the second X-ray line sensor are arranged side by side, the adjustment determination unit can accurately determine the adjustment direction of the X-ray source. .

  In addition, the X-ray foreign object detection apparatus according to the present invention includes a difference in size and shape between the trapezoidal shape formed by the first waveform and the trapezoidal shape formed by the second waveform, and the amount of adjustment required for the X-ray source. Constant adjustment means for preliminarily storing a constant between the adjustment determination means for determining the adjustment direction of the X-ray source, the difference in size and shape, and the constant stored in the constant storage means, The amount of adjustment required for the X-ray source is determined based on the above, and the display means displays the adjustment direction and the amount of adjustment required determined by the adjustment determination means.

  With this configuration, it is possible to adjust the X-ray source to an appropriate position in a short time or with a small number of trials by determining and displaying not only the adjustment direction of the X-ray source but also the amount of adjustment required.

  Further, the X-ray foreign object detection device according to the present invention is determined by the position determining means for displacing the X-ray source supported by the supporting means to the upstream side in the transport direction or the downstream side in the transport direction, and the adjustment determination means. Drive control means for driving and controlling the position displacement means in accordance with the adjustment direction and the adjustment required.

  With this configuration, since the drive control unit drives and controls the position displacement unit according to the determined adjustment direction and necessary adjustment, the X-ray source can be automatically adjusted to an appropriate position.

  In the X-ray foreign object detection device according to the present invention, the second X-ray line sensor is disposed below the first X-ray line sensor, and the adjustment determination means is a trapezoid formed by the first waveform. The adjustment direction of the X-ray source is determined so that the difference between the inclination on one end side of the shape and the inclination on the same side of the trapezoidal shape formed by the second waveform is small.

  With this configuration, even when the first X-ray line sensor and the second X-ray line sensor are arranged vertically, the adjustment determination unit can accurately determine the adjustment direction of the X-ray source. it can.

  The present invention can provide an X-ray foreign object detection device that can substantially match the size and shape of an object to be inspected on two X-ray images obtained by the energy subtraction method and prevent a decrease in foreign object detection performance. .

It is a perspective view which shows schematic structure of the X-ray foreign material detection apparatus which concerns on one embodiment of this invention. It is a figure which shows the side surface and internal structure of the X-ray foreign material detection apparatus which concern on one embodiment of this invention. It is a figure which shows the horizontal arrangement | positioning of the two X-ray detectors of the X-ray foreign material detection apparatus which concerns on one embodiment of this invention. It is a figure which shows the biaxial adjustment mechanism of the X-ray tube of the X-ray foreign material detection apparatus which concerns on one embodiment of this invention. It is a figure which shows the positional relationship of the X-ray tube and X-ray line sensor of the X-ray foreign material detection apparatus which concerns on one embodiment of this invention. It is a figure which shows the difference of the waveform produced by the shift | offset | difference of the relative position of the X-ray tube and X-ray line sensor of the X-ray foreign material detection apparatus which concerns on one embodiment of this invention. It is a figure which shows vertical arrangement | positioning of the two X-ray detectors of the X-ray foreign material detection apparatus which concerns on one embodiment of this invention. It is a figure explaining the method of calculating | requiring the change of a slope width by displacing an X-ray tube on an X-axis in an X-ray foreign material detection apparatus. It is a graph which shows the change of the position on the X-axis of an X-ray tube, and the difference of inclination.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the configuration will be described.

  As shown in FIG. 1, the X-ray foreign object detection device 1 includes a transport unit 2 and a detection unit 3 inside a housing 4, and a display 5 at the upper front of the housing 4.

  The conveyance unit 2 sequentially conveys the inspection object W at a predetermined interval. This conveyance part 2 is comprised by the belt conveyor arrange | positioned horizontally within the housing | casing 4, for example. The transport unit 2 serves as a transport surface for the inspection object W loaded from the carry-in port 7 at a transport speed set in advance by driving the drive motor 6 shown in FIG. 1 toward the carry-out port 8 side (X direction in the figure). The belt surface 2a is conveyed. A space passing through the belt surface 2 a from the carry-in entrance 7 to the carry-out exit 8 within the housing 4 forms a transport path 21.

  The detection unit 3 irradiates the inspection object W sequentially conveyed with X-rays in the inspection space 22 in the middle of the conveyance path 21 and detects X-rays transmitted through the inspection object W. An X-ray generator 9 disposed at a predetermined height above the inspection space 22 in the middle of 21 and an X-ray detector 10 disposed opposite to the X-ray generator 9 in the transport unit 2 are provided. ing.

  The X-ray generator 9 includes an X-ray tube 31 as a cylindrical X-ray source inside a casing (not shown), and the casing and the X-ray tube 31 are insulated by insulating oil or insulating resin. ing. In the present embodiment, the X-ray tube 31 can be moved on the X-axis (conveying direction of the conveying unit 2) and on the Y-axis (the width direction of the conveying unit 2) by a biaxial adjusting mechanism described later. X-rays are generated by irradiating an anode target with an electron beam from the cathode of the X-ray tube 31. The X-ray tube 31 is arranged such that its longitudinal direction is the conveyance direction (X direction) of the inspection object W. The X-rays generated by the X-ray tube 31 are directed toward the lower X-ray detector 10 by a slit (not shown) disposed on the upper surface of the examination space 22 (see FIGS. 1 and 2). Thus, irradiation is performed so as to cross the transport direction (X direction).

  The slit is configured to be displaced together with the X-ray tube 31 that is displaced by the biaxial adjustment mechanism.

  The X-ray detector 10 includes an X-ray line sensor 50 in which a plurality of detection elements are linearly arranged in the Y direction orthogonal to the transport direction on the plane in the transport direction (X direction) of the object W to be transported. ing. In the present embodiment, as shown in FIG. 7, the X-ray line sensor 50 is vertically arranged, that is, arranged in the vertical direction at a position (substantially vertically below) across the belt surface 2a and facing the X-ray tube 31. The two X-ray line sensors 51 and 52 are arranged side by side at a position (substantially vertically below) across the belt surface 2a (substantially vertically below), as shown in FIG. Two X-ray line sensors 51 and 52 arranged in the direction are provided.

  In FIG. 7, an X-ray line sensor 52 is arranged below the X-ray line sensor 51, that is, in a direction away from the X-ray tube 31.

  In FIG. 3, an X-ray line sensor 52 is arranged downstream of the X-ray line sensor 51.

  The X-ray line sensor 51 outputs a low-energy detection signal irradiated from the X-ray tube 31 and transmitted through the inspection object W, and the X-ray line sensor 52 is irradiated from the X-ray tube 31 and inspection object W. The detection signal of high energy which permeate | transmitted is output.

  In the present embodiment, for example, a filter for attenuating X-rays is attached to the X-ray line sensor 51 or the sensitivity of the X-ray line sensor 51 is reduced, whereby the detection signal of the X-ray line sensor 52 is converted to the X-ray line sensor. The energy is made higher than 51.

  That is, the X-ray foreign object detection apparatus 1 includes one X-ray tube 31 and two X-ray line sensors 51 and 52, and combines the images from the two X-ray line sensors 51 and 52 to emphasize the foreign substances. It adopts the energy subtraction method to obtain the image.

  The X-ray line sensors 51 and 52 include a scintillator (not shown) that emits light (fluorescence) upon receiving X-rays and a light receiving element that receives light from the scintillator.

  Here, in the present embodiment, the X-ray detector 10 outputs detection signals (luminance value data) of the X-ray line sensors 51 and 52 from a built-in A / D conversion unit (not shown), and this detection signal ( Density data obtained by converting (luminance value data) into digital data is output as data of X-ray image data. Note that an A / D conversion unit may be provided outside the X-ray detector 10.

  The X-ray detector 10 including the X-ray line sensors 51 and 52 outputs X-ray image data necessary for determining the presence or absence of contamination by a general control unit 40 (see FIG. 2) described later. ing.

  As shown in FIG. 2, X-ray shielding shielding curtains 16 are suspended and arranged at a plurality of locations along the conveyance direction (X direction) on the ceiling portion 21 a in the conveyance path 21. The shielding curtain 16 is composed of a rubber sheet mixed with lead powder that shields X-rays and processed into a good shape (a state in which the upper part is connected and the lower part is divided into strips), and is conveyed from the inspection space 22. This prevents X-rays from leaking outside the housing 4 via the path 21.

  In the present embodiment, two shielding curtains 16 are provided between the carry-in entrance 7 and the inspection space 22 and between the examination space 22 and the carry-out exit 8, respectively. Even when a gap is generated due to elastic deformation due to contact with the inspection object W, the other shielding curtain 16 shields X-rays, so that leakage of X-rays can be prevented without exceeding the leakage reference amount.

  Note that a slit is disposed on the upper surface of the inspection space 22, and the lower surface and side surfaces of the inspection space 22 are substantially closed by a housing 4 or the like for shielding X-rays. An inner space surrounded by the shielding curtain 16, the slit, the housing 4, and the like in the transport path 21 constitutes an inspection space 22.

  The X-ray foreign matter detection apparatus 1 includes a comprehensive control unit 40 that performs comprehensive control including determination of the presence or absence of foreign matter in the inspection object W based on density data received from the X-ray detector 10.

  The comprehensive control unit 40 performs comprehensive control of the X-ray foreign matter detection apparatus 1 and detects density data from the X-ray line sensors 51 and 52 and activates the density data at a predetermined timing, respectively. Detection unit 61, 62, storage unit 43 that stores a plurality of density data from data detection units 61, 62, and an image of density data from X-ray line sensors 51, 52 (hereinafter simply referred to as an image) An image processing unit 44 that performs image processing such as composition processing and filter processing, and an image subjected to image processing by the image processing unit 44 is discriminated from the object W to be inspected to determine whether foreign matter is mixed in. And a determination unit 48 for determination. The determination result by the determination unit 48 is displayed on the display 5.

  The data detection unit 60 includes two data detection units 61 and 62 in the present embodiment, and density data input at a predetermined timing with respect to the density data from the X-ray line sensors 51 and 52, that is, a predetermined level. Only data within the range of data validation input timing is validated.

  The storage unit 43 temporarily stores data validated by the data detection units 61 and 62 among the data output from the X-ray line sensors 51 and 52, and can store and read images at high speed. It consists of possible memory.

  The image processing unit 44 performs image processing such as synthesis processing and filter processing on the density data images from the X-ray line sensors 51 and 52.

  The determination unit 48 detects foreign matter from the inspected object W on the image subjected to the image processing by the image processing unit 44, and determines whether foreign matter is mixed.

  In addition, the X-ray foreign object detection device 1 is configured to perform setting operations and selection operations for the X-ray output of the X-ray generator 9, the conveyance speed of the inspection object W, the inspection parameters of the X-ray detector 10, the operation mode, and the like. The setting unit 49 is disposed next to the display 5 at the upper front of the housing 4.

  As shown in FIGS. 2 and 4, in this embodiment, as a mechanism for adjusting the positions of the X-ray tube 31 on the X axis and the Y axis, an X-ray unit including the X-ray tube 31 therein. A support mechanism 100 is provided to support 33 so as to be displaceable on two axes. Here, the X-ray unit 33 may have a mono tank configuration including a high voltage generation unit, or a configuration in which the high voltage generation unit is a separate unit.

  The support mechanism 100 includes a first stage 101 that supports an X-ray unit 33 provided with an X-ray tube 31 therein on the upper surface, a second stage 102 that supports the first stage 101 from below, and a second stage 102 that moves downward. And a third stage 103 supported from the outside.

  The first stage 101 is supported by the second stage 102 so as to be slidable on the Y axis when the convex portions 101a on the lower surfaces of both ends of the first stage 101 are guided in the concave portions 102a on the upper surface of the second stage 102. ing.

  The second stage 102 is supported by the third stage 103 so as to be slidable on the X axis when the convex portions 102c on the lower surfaces of both ends of the second stage 102 are guided in the concave portions 103c on the upper surface of the third stage 103. ing.

  On one end side of the second stage 102 on the Y-axis, a Y-axis adjusting member 111 that contacts the one end side of the first stage 101 and adjusts the position of the first stage 101 on the Y-axis is connected to the second stage 102. It is provided via a mounting stay 102b formed integrally or separately.

  On the other end side of the second stage 102 on the Y axis, a compression spring 113 is provided that contacts the other end side of the first stage 101 and presses the first stage 101 against the Y axis adjusting member 111 side. Yes.

  The Y-axis adjustment member 111 has a mechanism similar to that of a micrometer. When the Y-axis adjustment handle 111a is manually operated or rotated by the Y-axis drive motor 112, the plunger 111b moves forward or backward, and the first stage 101 The position on the Y axis is displaced.

  The Y-axis drive motor 112 is composed of a pulsed stepping motor, and its output shaft is connected to the Y-axis adjustment handle 111a.

  One end of the third stage 103 on the Y-axis is in contact with one end of an L-shaped member 116 rotatably provided on the second stage 102 to displace the other end of the L-shaped member 116. Thus, the X-axis adjusting member 114 that adjusts the position of the second stage 102 on the X-axis is provided via the mounting stay 103 b that is formed integrally with or separately from the third stage 103.

  On the other end side of the third stage 103, there is provided a compression spring 117 that contacts the other end side of the second stage 102 and presses the second stage 102 toward the X-axis adjusting member 114. The X-axis adjustment member 114 has the same mechanism as the micrometer. When the X-axis adjustment handle 114a is manually operated or rotated by the X-axis drive motor 115, the second stage is interposed via the L-shaped member 116. The position of 102 on the X axis is displaced.

  The X-axis drive motor 115 is composed of a pulsed stepping motor, and its output shaft is connected to the X-axis adjustment handle 114a.

  Further, in the present embodiment, when adjusting the position of the X-ray tube 31 on the X-axis and the Y-axis, as shown in FIG. 4, a polyethylene block or the like that outputs a relatively dark X-ray image, etc. A rectangular parallelepiped inspection object W is used as the reference inspection object Ws, and the reference inspection object Ws obtained from the X-ray image data output from the X-ray line sensor 51 and the X-ray image data output from the X-ray line sensor 52 is used. Direction of the X-ray tube 31 on two axes so that the sizes and shapes of the two X-ray images are equal by comparing the shapes of the first waveform and the second waveform representing the density change in the transport direction (And adjustment amount) are calculated.

  Here, as shown in FIG. 6, the first waveform and the second waveform are inspected based on X-ray image data with the X-axis direction (or Y-axis direction) of the reference inspection object Ws as the horizontal axis. This is a waveform when the vertical axis is converted into a luminance value that increases the difference between the object W and the background, and the portion corresponding to the luminance value of the reference object Ws has a trapezoidal shape. The first waveform and the second waveform are formed by waveform shaping. For example, when the X axis direction is the horizontal axis, the average value of a predetermined detection section in the Y axis direction is set as one data. Scan in the X-axis direction.

  Here, in FIG. 6, the length of the upstream side on the X axis of the trapezoidal shape formed by the first waveform is L1L, the length of the downstream side is L1R, and the trapezoidal shape formed by the second waveform. The length of the upstream side on the X axis is indicated by L2L, and the length of the downstream side is indicated by L2L. Further, the angle of the upstream end point on the X axis of the lower base of the trapezoid shape formed by the first waveform is θ1L, the angle of the downstream end point is θ1R, and the X axis of the lower base of the trapezoid shape formed by the second waveform The angle of the upstream end point is indicated by θ2L, and the angle of the downstream end point is indicated by θ2R. In addition, at a predetermined height of the trapezoid shape formed by the first waveform and the trapezoid shape formed by the second waveform, the width of the trapezoid shape formed by the first waveform on the X axis is L1H, and the trapezoid formed by the second waveform. The width of the shape on the X axis is indicated by L2H. In this embodiment, L1H and L2H use a width (half width) at an intermediate height between the trapezoid shape formed by the first waveform and the trapezoid shape formed by the second waveform.

  Of the X-ray line sensor 51 and the X-ray line sensor 52, the lower base of the trapezoidal shape becomes longer in the waveform having the smaller incident angle of the X-ray irradiated from the X-ray tube 31.

  The comprehensive control unit 40 is a first unit that shows a change in light and shade in the transport direction of the reference inspection object Ws obtained from the X-ray image data output from the X-ray line sensor 51 and the X-ray image data output from the X-ray line sensor 52. An adjustment determination unit 81 is provided as means for comparing the shape of the waveform and the second waveform and obtaining the adjustment direction of the position of the X-ray tube 31 and the amount of adjustment required so that the sizes and shapes of the two X-ray images are equal. ing. The adjustment determination unit 81 obtains a first waveform and a second waveform that indicate a change in density in the conveyance direction of the reference inspection object Ws, respectively, and based on the difference between the first waveform shape and the second waveform shape, The adjustment direction of the X-ray tube 31 is determined.

  As shown in FIG. 3, when the X-ray line sensors 51 and 52 are arranged side by side, the X-ray tube 31 is located between the X-ray line sensor 51 and the X-ray line sensor 52 as shown in FIG. 5. The operation of the adjustment determination unit 81 when it is arranged not at the position C (appropriate position) on the line but at the position D downstream (right side) of the line due to an assembly error or the like will be described.

  In this case, the adjustment determination unit 81 determines that the second waveform has a trapezoidal width L1H formed by the first waveform at a predetermined height of the trapezoidal shape formed by the first waveform and the trapezoidal shape formed by the second waveform. When the trapezoidal shape is longer than the width L2H, or the angle θ1L of the upstream end of the lower base of the trapezoid formed by the first waveform is the angle of the downstream end of the trapezoid of the trapezoid formed by the second waveform When it is smaller than θ2R, or when the length L1L of the upstream side of the trapezoidal shape formed by the first waveform is longer than the length L2R of the downstream side of the trapezoidal shape formed by the second waveform, FIG. Therefore, it is determined that the adjustment direction of the X-ray tube 31 is on the upstream side in the transport direction.

  In this embodiment, since a position sensor or the like for measuring the position of the X-ray tube 31 on two axes is not provided, an adjustment amount (distance) required for the X-ray tube 31 to be in an appropriate position is directly obtained. However, in the X axis (or Y axis), there is a constant relationship between the difference in the length of the bottom base in each trapezoid of the first waveform and the second waveform and the amount of adjustment required. Therefore, by storing the respective constants of the X axis and the Y axis, the adjustment determining unit 81 can calculate the necessary adjustment amount.

  Therefore, the overall control unit 40 includes a constant storage unit 80 that stores the above constants in advance for each of the X axis and the Y axis. Then, the adjustment determination unit 81 determines the difference between the constant stored in the constant storage unit 80 and the length of the lower base of the trapezoid of the first waveform and the second waveform acquired using the reference inspection object Ws. Based on this, the amount of adjustment required for the X-axis and Y-axis of the X-ray tube 31 is adjusted.

  The constant is the difference between the lengths of the lower bases of the trapezoids of the first waveform and the second waveform when the X-ray tube 31 is intentionally moved a predetermined distance on the X axis (or Y axis) in advance. It can be obtained from the amount of change.

  Further, the adjustment determination unit 81 outputs the determination result to the display unit 5. For example, a message such as “X axis: −1.5 mm, Y axis: +3 mm” is displayed on the display 5 as the adjustment direction and the amount of adjustment required for the X-ray tube 31.

  The general control unit 40 includes a drive control unit 82 that controls the drive of the Y-axis drive motor 112 and the X-axis drive motor 115 according to the adjustment direction and the amount of adjustment required of the X-ray tube 31 determined by the adjustment determination unit 81. Yes.

  The drive control unit 82 determines drive pulses for the Y-axis drive motor 112 and the X-axis drive motor 115 according to the adjustment direction and the amount of adjustment required determined by the adjustment determination unit 81, and the Y-axis drive motor 112 is determined based on the drive pulses. The X-axis drive motor 115 is driven.

  Therefore, when the adjustment direction and the required adjustment amount of the X-ray tube 31 are determined, the adjustment direction and the required adjustment amount are displayed on the display 5 and the drive control unit 82 controls the Y-axis drive motor 112 and the X-axis drive. The motor 115 is driven and controlled, and the position of the X-ray tube 31 on the two axes is adjusted to an appropriate position.

  In the present embodiment, there are an automatic adjustment mode and a manual adjustment mode as the operation mode of the overall control unit 40. When the operation mode is set to the automatic adjustment mode, the adjustment direction and the amount of adjustment required by the display 5 are set. When both the display and the drive control of the Y-axis drive motor 112 and the X-axis drive motor 115 are performed by the drive control unit 82 and the operation mode is set to the manual adjustment mode, the adjustment direction and the adjustment required by the display 5 are required. Only the amount is displayed, and the user operates the Y-axis adjustment handle 111a and the X-axis adjustment handle 114a.

  Next, the operation of the X-ray foreign object detection apparatus 1 configured as described above will be described.

  First, when the operation mode is set to the automatic adjustment mode, the comprehensive control unit 40 scans the reference inspection object Ws to generate the first waveform and the second waveform from the X-ray line sensor 51 and the X-ray line sensor 52. And the adjustment determination unit 81 determines the adjustment direction and the amount of adjustment required on the X-axis of the X-ray tube 31 based on the difference between the shape of the first waveform and the shape of the second waveform. The discrimination result is displayed on the display 5 and the drive control unit 82 controls the drive of the X-axis drive motor 115. Thereby, the position on the X-axis of the X-ray tube 31 is adjusted to an appropriate position.

  Next, the overall control unit 40 scans the reference inspection object Ws again to obtain the first waveform and the second waveform, and the adjustment determination unit 81 causes the first waveform shape and the second waveform shape to be obtained. Based on the difference, the adjustment direction on the Y-axis of the X-ray tube 31 and the amount of adjustment required are determined, the determination result is displayed on the display 5, and the drive control unit 82 drives and controls the Y-axis drive motor 112. . Thereby, the position on the Y-axis of the X-ray tube 31 is adjusted to an appropriate position.

  On the other hand, when the operation mode is set to the manual adjustment mode, the comprehensive control unit 40 scans the reference inspection object Ws and outputs the first waveform and the second waveform from the X-ray line sensor 51 and the X-ray line sensor 52. And the adjustment determination unit 81 determines the adjustment direction and the amount of adjustment required on the X-axis of the X-ray tube 31 based on the difference between the shape of the first waveform and the shape of the second waveform. The discrimination result is displayed on the display 5. Thereby, when the user operates the X-axis adjustment handle 114a, the position of the X-ray tube 31 on the X-axis is adjusted to an appropriate position.

  Next, the overall control unit 40 scans the reference inspection object Ws again to obtain the first waveform and the second waveform, and the adjustment determination unit 81 causes the first waveform shape and the second waveform shape to be obtained. Based on the difference, the adjustment direction on the Y axis of the X-ray tube 31 and the amount of adjustment required are determined, and the determination result is displayed on the display 5. Thereby, when the user operates the Y-axis adjustment handle 111a, the position of the X-ray tube 31 on the Y-axis is adjusted to an appropriate position.

  Note that the adjustment determination unit 81 may be configured to determine only the adjustment direction of the X-ray tube 31. In this case, the user obtains an image using the reference inspection object Ws and displays on the display 5. The X-ray tube 31 can be adjusted to an appropriate position by repeating the adjustment of the reference distance of the X-ray tube 31 according to the displayed adjustment direction several times.

  Next, the operation when the X-ray line sensors 51 and 52 are arranged vertically as shown in FIG. 7 will be described.

  In this case, the adjustment determination unit 81 has a small difference in inclination with respect to the inclination on one end side of the trapezoidal shape formed by the first waveform and the second waveform in the X-axis direction that is the conveyance direction. The adjustment direction is determined as follows. The difference in inclination in this case is, for example, the inclination length (the length of the side of the trapezoid), the inclination angle (the size of the base angle of the trapezoid), the slope width (the horizontal width of the trapezoidal inclined portion), etc. The inclination difference and the moving direction are temporarily stored.

  Also, the adjustment direction is compared with the previously stored difference in inclination, and if the difference is larger than the previous time, it is determined that the direction is opposite to the previous movement direction, and if the difference is smaller than the previous time, It is determined that the direction is the same as the previous movement direction. In the case of the first determination of the adjustment direction in which the difference in inclination is not temporarily stored, a predetermined direction is designated.

  Further, when the operation mode is set to the automatic adjustment mode, as shown in FIG. 8, the position of the X-ray tube 31 is intentionally displaced in the X-axis direction that is the transport direction, and a plurality of X-ray tubes 31 are thereby moved. At the position of the X-ray line sensors 51 and 52, the X-ray line sensors 51 and 52 are positioned on the downstream side of the first waveform and the second waveform when positioned on the upstream side of the straight line connecting the centers in the X-axis direction. As shown in FIG. 9, the optimum position of the X-ray tube 31 in the X-axis direction is calculated by obtaining a graph of the difference in inclination with the first waveform and the second waveform at the time. The position where the difference in inclination is minimized (the position corresponding to the bottom of the U-shaped graph) is the optimum position, and at this time, it is on a straight line connecting the X-axis direction centers of the X-ray line sensors 51 and 52. The X-ray tube 31 will be located. That is, with respect to the adjustment direction on the X-axis of the X-ray tube 31, the adjustment determination unit 81 determines that the direction in which the difference in inclination is small is the adjustment direction of the X-ray tube 31. Moreover, the adjustment determination part 81 determines the amount of adjustment required based on the graph of the inclination difference of FIG.

  As described above, the X-ray foreign object detection device 1 according to the present embodiment can adjust the position of the X-ray tube 31 on the upstream side in the transport direction of the transport unit 2 or on the downstream side in the transport direction on a plane parallel to the transport surface. A first waveform and a second waveform indicating a change in light and shade in the conveyance direction of the object W from the first X-ray image data and the second X-ray image data, respectively. An adjustment determination unit 81 that determines an adjustment direction of the X-ray tube 31 based on a difference between the first waveform shape and the second waveform shape, and a display 5 that displays the adjustment direction determined by the adjustment determination unit 81 , Provided.

  With this configuration, since the adjustment direction of the conveyance direction of the X-ray tube 31 is displayed on the display device 5, the user adjusts the position of the X-ray tube 31 in accordance with the displayed adjustment direction, whereby the X-ray image is displayed. The size and shape of the inspection object W in the data can be substantially matched. Therefore, the size and shape of the inspection object W on the two X-ray images obtained by the energy subtraction method can be substantially matched to prevent the foreign matter detection performance from being deteriorated.

  Further, in the X-ray foreign object detection device 1 according to the present embodiment, the X-ray line sensor 52 is disposed on the downstream side in the transport direction of the X-ray line sensor 51, and the adjustment determination unit 81 has the first waveform and the second waveform. When the width L1H of the first waveform is longer than the width L2H of the second waveform at a predetermined height of the waveform, it is determined that the adjustment direction of the X-ray tube 31 is upstream in the transport direction. .

  Further, in the X-ray foreign object detection device 1 according to the present embodiment, the X-ray line sensor 52 is disposed on the downstream side in the transport direction of the X-ray line sensor 51, and the adjustment determination unit 81 has a trapezoidal shape formed by the first waveform. When the angle θ1L of the upstream end of the lower base is smaller than the angle θ2R of the downstream end of the trapezoidal shape formed by the second waveform, the adjustment direction of the X-ray tube 31 is the upstream side of the transport direction It is characterized by determining.

  Further, in the X-ray foreign object detection device 1 according to the present embodiment, the X-ray line sensor 52 is disposed on the downstream side in the transport direction of the X-ray line sensor 51, and the adjustment determination unit 81 has a trapezoidal shape formed by the first waveform. When the length L1L of the upstream side is longer than the length L2R of the downstream side of the trapezoidal shape formed by the second waveform, it is determined that the adjustment direction of the X-ray tube 31 is the upstream side in the transport direction It is characterized by doing.

  With this configuration, even when the X-ray line sensor 51 and the X-ray line sensor 52 are arranged side by side, the adjustment determination unit 81 can accurately determine the adjustment direction of the X-ray tube 31.

  In addition, the X-ray foreign object detection device 1 according to the present embodiment has a difference in size and shape between the trapezoid shape formed by the first waveform and the trapezoid shape formed by the second waveform, and the amount of adjustment required for the X-ray tube 31. A constant storage unit 80 that stores the constants between and the adjustment determination unit 81 to determine the adjustment direction of the X-ray tube 31 and the difference in size and shape and the constants stored in the constant storage unit 80 The adjustment amount of the X-ray tube 31 is determined based on the above, and the display 5 displays the adjustment direction and the adjustment amount determined by the adjustment determination unit 81.

  With this configuration, not only the adjustment direction of the X-ray tube 31 but also the determination and display of the amount of adjustment required, the X-ray tube 31 can be adjusted to an appropriate position in a short time or with a small number of trials.

  In addition, the X-ray foreign object detection device 1 according to the present embodiment includes an X-axis drive motor 115 that displaces the X-ray tube 31 supported by the support mechanism 100 to the upstream side in the transport direction or the downstream side in the transport direction, and an adjustment determination unit. And a drive control unit 82 that drives and controls the X-axis drive motor 115 in accordance with the adjustment direction determined by 81 and the need for adjustment.

  With this configuration, the drive control unit 82 drives and controls the X-axis drive motor 115 in accordance with the determined adjustment direction and adjustment required, so that the X-ray tube 31 can be automatically adjusted to an appropriate position.

  Also, in the X-ray foreign object detection device 1 according to the present embodiment, the X-ray line sensor 52 is disposed below the X-ray line sensor 51, and the adjustment determination unit 81 has one end side of a trapezoidal shape formed by the first waveform. The adjustment direction of the X-ray tube 31 is determined so that the difference between the inclination of the trapezoid formed by the second waveform and the inclination on the same side of the trapezoidal shape becomes small.

  With this configuration, even when the X-ray line sensor 51 and the X-ray line sensor 52 are vertically arranged, the adjustment determination unit 81 can accurately determine the adjustment direction of the X-ray tube 31.

  As described above, the X-ray foreign object detection apparatus according to the present invention can prevent the deterioration of the foreign object detection performance by substantially matching the size and shape of the inspection object on the two X-ray images obtained by the energy subtraction method. This is useful as an X-ray foreign object detection apparatus that employs an energy subtraction method that obtains an image in which foreign objects are emphasized by synthesizing images from a plurality of X-ray line sensors.

DESCRIPTION OF SYMBOLS 1 X-ray foreign material detection apparatus 2 Conveyance part (conveyance means)
2a Belt surface (conveying surface)
3 Detection unit 4 Housing 5 Display (display means)
6 drive motor 7 carry-in port 8 carry-out port 9 X-ray generator 10 X-ray detector 16 shielding curtain 21 transport path 21a ceiling part 22 inspection space 31 X-ray tube (X-ray source)
40 general control unit 43 storage unit 44 image processing unit (image composition means)
48 determination part (determination means)
49 Setting unit 51 X-ray line sensor (first X-ray line sensor)
52 X-ray line sensor (second X-ray line sensor)
61, 62 Data detection unit 80 Constant storage unit (constant storage means)
81 Adjustment determination unit (adjustment determination means)
82 Drive control unit (drive control means)
100 Support mechanism (support means)
101 First stage 102 Second stage 103 Third stage 114 X-axis adjusting member (supporting means)
115 X-axis drive motor (position displacement means)
W inspection object Ws reference inspection object

Claims (7)

Transport means (2) for transporting the object to be inspected on the transport surface (2a);
An X-ray source (31) for irradiating the inspection object conveyed on the conveyance surface with X-rays;
From the first X-ray image data and the X-ray source corresponding to the X-rays arranged at the position facing the X-ray source across the transport surface, irradiated from the X-ray source and transmitted through the inspection object A first X-ray line sensor (51) and a second X-ray line sensor (52) that respectively output second X-ray image data corresponding to the X-rays irradiated and transmitted through the inspection object;
Image synthesizing means (44) for synthesizing the first X-ray image data and the second X-ray image data and outputting as one image data corresponding to the object;
An X-ray foreign object detection device (1) comprising: determination means (48) for determining the presence or absence of a foreign substance in the object to be inspected based on image data output by the image composition means;
Support means (100) for supporting the X-ray source so that the position of the X-ray source can be adjusted on the upstream side or the downstream side in the transport direction of the transport means on a plane parallel to the transport surface;
A first waveform and a second waveform representing a change in density in the conveyance direction of the object to be inspected are obtained from the first X-ray image data and the second X-ray image data, respectively, and the first waveform shape And an adjustment determining means (81) for determining the adjustment direction of the X-ray source based on the difference between the second waveform shape and the second waveform shape;
An X-ray foreign matter detection apparatus comprising: display means (5) for displaying an adjustment direction determined by the adjustment determination means. The second X-ray line sensor is disposed downstream of the first X-ray line sensor in the transport direction;
When the adjustment determination means has a predetermined height of the first waveform and the second waveform, and the width of the first waveform is longer than the width of the second waveform, the adjustment direction of the X-ray source The X-ray foreign object detection device according to claim 1, wherein the X-ray foreign object detection device is determined to be upstream in the transport direction. The second X-ray line sensor is disposed downstream of the first X-ray line sensor in the transport direction;
When the angle of the upstream end of the trapezoid-shaped lower base formed by the first waveform is smaller than the angle of the downstream end of the trapezoid-shaped lower base formed by the second waveform, The X-ray foreign object detection apparatus according to claim 1, wherein the X-ray source adjustment direction is determined to be upstream in the transport direction. The second X-ray line sensor is disposed downstream of the first X-ray line sensor in the transport direction;
The X-ray source when the adjustment determining means has a length of the upstream side of the trapezoidal shape formed by the first waveform longer than the length of the downstream side of the trapezoidal shape formed by the second waveform. The X-ray foreign object detection device according to claim 1, wherein the adjustment direction is determined to be upstream of the conveyance direction. Constant storage means (80) for storing in advance a constant between the difference in size and shape between the trapezoidal shape formed by the first waveform and the trapezoidal shape formed by the second waveform, and the amount of adjustment required for the X-ray source. )
The adjustment determining unit determines an adjustment direction of the X-ray source, and determines an adjustment amount of the X-ray source based on the difference in size and shape and a constant stored in the constant storage unit. ,
The X-ray foreign object detection device according to claim 1, wherein the display unit displays the adjustment direction and the amount of adjustment required determined by the adjustment determination unit. Position displacement means (115) for displacing the X-ray source supported by the support means to the upstream side in the transport direction or the downstream side in the transport direction;
6. A drive control means (82) for drivingly controlling the position displacement means in accordance with the adjustment direction determined by the adjustment determination means and the need for adjustment. The X-ray foreign material detection apparatus according to claim 1. The second X-ray line sensor is disposed below the first X-ray line sensor,
The adjustment determining means adjusts the adjustment direction of the X-ray source so that a difference between an inclination on one end side of the trapezoidal shape formed by the first waveform and an inclination on the same side of the trapezoidal shape formed by the second waveform is reduced. The X-ray foreign object detection device according to claim 1, wherein the determination is performed.

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