JP5452131B2 - X-ray detector and X-ray inspection apparatus - Google Patents

Description

  The present invention relates to an X-ray detector and an X-ray inspection apparatus for detecting foreign matter mixed in an object to be inspected such as meat, fish, processed food, and medicine, and in particular, the object to be inspected by being irradiated from an X-ray generator. The present invention relates to an X-ray detector and an X-ray inspection apparatus that detect transmitted X-rays.

  For example, an X-ray inspection apparatus has been conventionally used to detect the presence or absence of foreign matter in an inspection object such as food. In this type of conventional X-ray inspection apparatus, an X-ray generator is disposed on the upper side of the apparatus body, and an X-ray detector is attached to a position below the conveyor belt below the X-ray generator. X-rays emitted from the generation unit are received by the X-ray detection unit.

  In this type of X-ray inspection apparatus, linear sensor modules that receive X-rays from the X-ray generation unit are arranged side by side in the transport direction with respect to one X-ray generation unit, and each X-ray generation unit receives each X-ray from the X-ray generation unit. An X-ray variable body that varies the quality of each X-ray reaching the line sensor is provided, and each X-ray having a different quality transmitted through the inspection object is detected by each sensor module, thereby transmitting these X-rays. It is known that the amount of foreign matter in an inspection object is detected by distinguishing it from foreign matter that easily transmits X-rays and foreign matter that does not easily transmit X-rays (for example, see Patent Document 1). For example, this X-ray inspection apparatus can detect only a foreign substance with high sensitivity by calculating a difference between a high energy image and a low energy image acquired by a plurality of sensor modules.

  In addition, the X-ray detector is composed of two sensor modules arranged at the upper and lower positions along the X-ray transmission direction, and the upper sensor module is reflected by the visible light reflector after being converted into visible light by the scintillator. The X-ray transmission data corresponding to the X-ray transmission amount is output by the light receiving element, and the lower sensor module attenuates the X-ray energy in a predetermined band with the X-ray filter, and then converts it into visible light with the scintillator A device in which X-ray transmission data is output by a light receiving element is known (for example, see Patent Document 2).

JP 2002-168803 A JP 2002-365368 A

  However, since the sensor modules described in Patent Document 1 are arranged side by side in the transport direction, the balance between X-ray transmission data output from each sensor module is deteriorated, data mismatch, and density difference. There was a problem such as. On the other hand, as described in Patent Document 2, these problems can be solved by arranging the sensor modules side by side in the vertical direction, but in this case, the upper sensor module and the lower sensor module There has been a problem that the positional deviation of pixels occurs between the two.

  That is, the X-rays that are irradiated from the X-ray generation unit in the form of a substantially triangular screen by the slit and pass through the inspection object are perpendicular to the upper and lower sensor modules immediately below the X-ray generation unit. In the sensor module located at a position far from the X-ray generation unit, X-rays are incident at an angle. Therefore, the X-rays that have passed through the upper sensor module are located directly under the X-ray image. However, it is incident on the lower sensor module where the position is shifted in the X-ray image.

  For this reason, when the difference between the X-ray transmission data obtained from the upper sensor module and the X-ray transmission data obtained from the lower sensor module in order to detect the foreign matter is calculated, Spreads to other adjacent elements and is not correctly differentiated, which may reduce the sensitivity of foreign object detection.

  Therefore, the present invention has been made to solve the conventional problems as described above, and in the case of using an X-ray detection unit in which a plurality of sensor modules are arranged vertically, X-rays from each sensor module are used. It is an object of the present invention to provide an X-ray detector and an X-ray inspection apparatus that can detect a foreign object with high sensitivity by preventing displacement of transmission data.

  The X-ray detector according to the present invention includes a first sensor module group including a plurality of sensor modules that output first X-ray transmission data and second X-ray transmission data based on the intensity of incident X-rays. A second sensor module group that includes a plurality of sensor modules that output a plurality of sensor modules, wherein the first sensor module group and the second sensor module group overlap with an incident direction of the incident X-ray. The X-ray detectors are arranged such that each sensor module of the first sensor module group and each sensor module of the second sensor module group are arranged in a line at predetermined intervals, respectively, The distance between each sensor module in the first sensor module group and each sensor module in the second sensor module group corresponding to each sensor module. Wherein the modules and, each direction line connecting each respective corresponding points are determined respectively to focus in the focal region.

  With this configuration, the X-ray generation source is focused on the focusing region where the direction lines connecting the sensor modules having a one-to-one correspondence between the first sensor module group and the second sensor module group arranged in parallel converge. , The X-rays incident from the same direction can be detected, so the first X-ray transmission data from the first sensor module group and the second sensor module group It is possible to prevent the positional deviation of the second X-ray transmission data from and to detect foreign matter with high sensitivity.

  In addition, each direction line connects each corresponding point such as the midpoint or one end of each sensor module. For example, select which corresponding point is used according to the number of elements included in the sensor module. Good. That is, when the number of elements included in the module is large, by setting the midpoints as corresponding points, it is possible to suppress the shift amount at both ends where the positional shift is maximum. On the other hand, when the number of elements included in each module is small and the amount of deviation at the other end is in an allowable range, one end of each sensor module is used as a corresponding point, so that the arrangement of each sensor module is positioned at the end position. In any case, the first X-ray transmission data and the second X-ray transmission data respectively output from the first sensor module group and the second sensor module group each composed of a plurality of sensor modules. The positional deviation from the X-ray transmission data can be prevented.

  An X-ray inspection apparatus according to the present invention is an X-ray inspection apparatus that detects foreign matter in the inspection object from the amount of X-rays transmitted to the inspection object and transmitted through the inspection object. An X-ray generator that irradiates X-rays from a radiation source toward a region through which the inspection object passes, and an X-ray generation unit that are arranged in a direction orthogonal to the conveyance direction of the inspection object and are irradiated from the X-ray generation unit A first sensor module group including a plurality of sensor modules that receive X-rays transmitted through the inspection object and output first X-ray transmission data based on the amount of transmission of the X-rays and second X-ray transmission A second sensor module group including a plurality of sensor modules that output data, and the first sensor module group and the second sensor module group are juxtaposed along a direction in which the X-rays are transmitted X-ray detector and the first X-ray transmission A control unit for detecting foreign matter in the inspection object based on an image obtained by image calculation using the first image data based on the data and the second image data based on the second X-ray transmission data. The sensor modules of the second sensor module group corresponding to the sensor modules of the first sensor module group are arranged with an interval determined based on the transmission direction of the X-rays. It is characterized by that.

  With this configuration, it is possible to detect the foreign matter with high sensitivity by preventing the positional deviation of the X-ray transmission data from the first sensor module group and the second sensor module group.

  In the X-ray inspection apparatus according to the present invention, the sensor module includes a scintillator that converts X-rays into visible light, and X-rays that receive visible light converted by the scintillator and correspond to the amount of X-ray transmission. A plurality of light-receiving elements that output transmission data, and the first sensor module reflects visible light converted by the scintillator in a direction different from a direction in which the X-rays are transmitted. Special lecture is to have

  With this configuration, the light receiving element can be arranged in the X-ray reflection direction by the visible light reflector, so that the height of the sensor module can be suppressed.

  In the X-ray inspection apparatus according to the present invention, the X-ray transmission positions of the light receiving elements of the sensor modules of the first sensor module group and the light receiving elements of the sensor modules of the second sensor module group are mutually different. A plurality of light receiving elements of each sensor module of the second sensor module group are arranged so as to be coincident with each other.

  With this configuration, the X-ray passage positions coincide with each other, and it is possible to further prevent the positional deviation of the X-ray transmission data and detect foreign matter with higher sensitivity.

  According to the present invention, when an X-ray detection unit in which a plurality of sensor modules are arranged vertically is used, it is possible to detect foreign matter with high sensitivity by preventing positional deviation of X-ray transmission data from each sensor module. An X-ray detector and an X-ray inspection apparatus can be provided.

1 is a perspective view showing a schematic configuration of an X-ray inspection apparatus according to an embodiment of the present invention. It is a figure which shows the side surface and internal structure of the X-ray inspection apparatus which concern on one embodiment of this invention. It is a figure which shows the structure of the detection part of a X-ray inspection apparatus. (A), (b) is a figure which shows the structure of the horizontal direction of an X-ray detector. It is a figure which shows the structure of the vertical direction of a X-ray detector. It is a figure which shows the structure of the other vertical direction of an X-ray detector. It is a figure which shows the structure of the other vertical direction of an X-ray detector.

  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 inspection apparatus 1 includes a transport unit 2 and a detection unit 3 inside a housing 4, and a display unit 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 with respect to 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. 21 includes an X-ray generation unit 9 disposed at a predetermined height above an inspection space 22 in the middle of the 21 and an X-ray detector 10 disposed in the transport unit 2 so as to face the X-ray generation unit 9. Yes.

  An X-ray generation unit 9 as an X-ray generation source has a configuration in which a cylindrical X-ray tube 12 provided in a metal box 11 is immersed in insulating oil (not shown). X-rays are generated by irradiating an anode target with an electron beam from 12 cathodes. The X-ray tube 12 is arranged such that its longitudinal direction is the conveyance direction (X direction) of the inspection object W. X-rays generated by the X-ray tube 12 are irradiated toward the lower X-ray detector 10 so as to cross the transport direction (X direction) in a substantially triangular screen shape by a slit (not shown). It has become.

  As shown in FIG. 3, the X-ray detector 10 has a plurality of detection elements straight in the width direction, that is, the Y direction orthogonal to the transport direction on the plane of the transport direction (X direction) of the object W to be transported. It is arranged on the line. Specifically, the X-ray detector 10 includes an upper sensor module group 102 that extends linearly in a direction (Y direction) orthogonal to a plane in the conveyance direction (X direction) of the inspection object W and a lower stage. The sensor module group 101 is configured by arranging them along the X-ray irradiation direction. The X-ray detector 10 is configured to receive X-rays that are irradiated and transmitted toward the object W to be inspected. The X-ray detector 10 outputs first X-ray transmission data based on the X-ray intensity detected by the sensor module group 102, and based on the X-ray intensity detected by the sensor module group 101, Second X-ray transmission data is output.

  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. An inner space surrounded by the shielding curtain 16 in the conveyance path 21 constitutes an inspection space 22.

  The X-ray inspection apparatus 1 receives the X-ray transmission data from the X-ray detector 10 and displays and outputs a control unit 40 that inspects the presence or absence of foreign matter in the inspection object W, and the inspection results by the control unit 40. And a setting unit 45 for inputting various parameters and the like to the control unit 40.

  The control unit 40 includes a CPU, a memory, and the like. The control unit 40 stores the density data received from the X-ray detector 10, and synthesizes various filters for the density data read from the storage unit 42. An image processing unit 43 that performs image processing such as the above, and a determination unit 44 that determines the presence / absence of foreign matter by discriminating between the inspected object W and the foreign matter with respect to the image-processed density data. .

  The setting unit 45 includes a plurality of keys and switches operated by the user, and performs setting input of various parameters and selection of operation modes to the control unit 40.

  The display unit 5 is constituted by a flat display or the like, and displays the inspection result by the control unit 40. Further, the display unit 5 displays the pass / fail judgment result of the inspection object W with characters or symbols such as “OK” and “NG”, and sets the inspection results such as the total number of inspections, the number of non-defective products, and the total number of NGs as default settings. Or based on a request by a predetermined key operation from the setting unit 45.

  As shown in FIGS. 3, 4A, and 4B, the X-ray detector 10 includes a sensor module group including a plurality of sensor modules 102a, 102b, 102c,... Arranged in the width direction. 102 and a sensor module group 101 including a plurality of sensor modules 101a, 101b, 101c,... Arranged in the width direction. Further, the sensor module group 102 and the sensor module group 101 are irradiated with X-rays. It becomes the structure juxtaposed along the direction. In the present embodiment, the X-ray irradiation direction is generally the height direction on the belt surface 2a. In other words, the X-ray detector 10 has a configuration in which a plurality of sensor modules are arranged in both the width direction and the height direction.

  The sensor module group 102 is arranged on the upper stage, that is, on the side close to the X-ray generation unit 9 and receives X-rays emitted from the X-ray generation unit 9 first. The sensor module group 101 is arranged on the lower stage, that is, on the lower side of the sensor module group 102 on the side far from the X-ray generation unit 9 so as to receive the X-rays irradiated from the X-ray generation unit 9 and passed through the sensor module group 102. It has become.

  Each sensor module 102a, 102b, 102c,... Constituting the upper sensor module group 102 has the same size as each sensor module 102a, 102b, 102c,..., And each sensor module 102a, 102b,. 102c,... Are closely arranged so that there is no gap between them. The sensor modules 101a, 101b, 101c,... Constituting the lower sensor module group 101 have the same size in the sensor modules 101a, 101b, 101c,... And are determined based on the irradiation direction. Are spaced apart from each other.

  In the present embodiment, the upper sensor module 102a and the lower sensor module 101a, the upper sensor module 102b and the lower sensor module 101b, the upper sensor module 102c and the lower sensor module 101c (hereinafter referred to as sensor modules 102d and 101d and thereafter). In the same manner, the intervals of the lower sensor modules 101a, 101b, 101c,... Are provided so that the X-ray transmission positions coincide with each other.

  Specifically, as shown in FIG. 4A, the X-ray transmission position is located in the upper sensor modules 102a, 102b, 102c,... And the lower sensor modules 101a, 101b, 101c,. These midpoints are set as corresponding points 101ax, 101bx, 101cx, 102ax, 102bx, 102cx,..., And the direction lines of the X-rays emitted from the X-ray generation unit 9 are set as corresponding lines so as to be points. 150, the lower sensor modules 101a, 101b, 101c,... Are spaced so that the corresponding line 150 passes through the corresponding points 101ax, 101bx, 101cx, 102ax, 102bx, 102cx,. .

  Alternatively, as shown in FIG. 4B, the X-ray transmission position is one end of the upper sensor modules 102a, 102b, 102c,... And the lower sensor modules 101a, 101b, 101c,. As described above, the corresponding ends are defined as corresponding points 101ay, 101by, 101cy, 102ay, 102by, 102cy,..., And the X-ray direction line irradiated from the X-ray generation unit 9 is defined as a corresponding line 150. The intervals of the lower sensor modules 101a, 101b, 101c,... Are provided so that 150 passes through the corresponding points 101ay, 101by, 101cy, 102ay, 102by, 102cy,.

  That is, since each direction line connecting corresponding points of the sensor modules corresponding to the upper and lower sides is focused on the focusing area, if the X-ray generating section 9 is arranged in this focusing area, the X-ray generating section 9 is conversely arranged. Since the sensor modules corresponding to the top and bottom are arranged in the same direction when viewed from the side of the X-ray, the upper sensor module among the X-ray corresponding lines 150 irradiated from the X-ray generation unit 9 Corresponding line 150 passing through 102a passes through lower sensor module 101a, corresponding line 150 passing through upper sensor module 102b passes through lower sensor module 101b, and corresponding line 150 passes through upper sensor module 102c. The lower sensor modules 101a, 101b, 101c,... So as to pass through the lower sensor module 101c (the same applies hereinafter). Interval of it is provided.

  Here, the vertical distance between the X-ray generator 9 and the upper sensor module group 102 is L, the distance between the upper sensor module group 102 and the lower sensor module 101 is d, and the lower sensor modules 101a, 101b, and 101c. ,... Where a is the number of light receiving elements (photodiodes) arranged in the array, b is the element size in the array direction, and X is the interval between the lower sensor modules 101a, 101b, 101c,. By setting the distance X between the lower sensor module just below the X-ray generator 9 and the sensor module one side away from this sensor module to X = abd / L, image misalignment at both ends of the sensor module can be prevented. You can make it smaller. For example, when L = 550 mm, d = 3 mm, a = 128, and b = 0.8 mm, X = 0.55 mm. In addition, the interval Xn between the nth (natural number) sensor module from the lower sensor module directly below the X-ray generator 9 and the sensor module one side away from this sensor module is Xn = n · abd / L. .

  Thus, the upper sensor modules 102a, 102b, 102c,... Are arranged by providing the lower sensor modules 101a, 101b, 101c,... So that the X-ray transmission positions coincide with each other. It is possible to detect the foreign matter with high sensitivity by preventing the positional deviation of the X-ray transmission data from the lower sensor modules 101a, 101b, 101c,.

  In addition to providing intervals in the lower sensor modules 101a, 101b, 101c,..., Each light receiving element 123 (see FIG. 5) of the upper sensor module 102a and each light receiving element of the lower sensor module 101a. Even between the elements 113 (see FIG. 5), the light receiving elements 113 of the lower sensor module 101a may be spaced so that the X-ray transmission positions coincide with each other. In this case, the X-ray passage positions coincide for each light receiving element, and the positional deviation of the X-ray transmission data can be further prevented, and foreign matters can be detected with higher sensitivity.

  In the following, details will be described by taking one sensor module 102a, 101a of each of the sensor module groups 102, 101 as an example. The sensor modules 102b, 102c,... Other than the sensor module 102a in the sensor module group 102 are configured in the same manner as the sensor module 102a, and the sensor modules 101b, 101c,. Is configured similarly to the sensor module 101a.

  As shown in FIG. 5, the sensor module 102a is provided in the upper stage, and the sensor module 101a is provided in the lower stage. The upper sensor module 102 a is provided with a scintillator 121 and a light receiving element 123. The lower sensor module 101a is provided with an X-ray filter 110, a scintillator 111, and a light receiving element 113. FIG. 5 is a schematic diagram, and normally, the scintillators (121, 111) and the light receiving elements (123, 113) are provided in close contact with each other.

  A plurality of light receiving elements 123 and 113 are arranged in a line in the depth direction of the figure, and are formed of photodiodes. The X-ray filter 110 and the scintillators 121 and 111 also have a predetermined length in the depth direction in the drawing along the arrangement of the light receiving elements 123 and 113.

  The X-ray filter 110 is composed of a variable quality material that changes the quality of X-rays. For example, the X-ray filter 110 is formed of a metal such as aluminum or copper, carbon, or a resin material in a thin plate shape. Is made up of. The X-ray filter 110 attenuates X-ray energy in a predetermined band received by the sensor module 101a. This predetermined band can be set by the material of the X-ray filter 110, for example, to obtain the X-ray energy of only the necessary X-ray energy band among the X-rays generated from the X-ray generation unit 9. Can do. For this reason, by using predetermined X-ray energy, it becomes possible to emphasize the inspected object W of different materials and the shadow of the foreign matter.

  At least on the sensor module 101a side, the quality of X-rays that have not been converted into visible light on the sensor module 102a side is varied. Thereby, the X-rays received by the sensor module 102a and the X-rays received by the sensor module 101a are made different in quality.

  The foreign substance detection operation of the X-ray inspection apparatus 1 having the above configuration will be described. The X-ray generator 9 irradiates the inspection object W with X-rays at an intermediate position where the inspection object W is conveyed by the conveyance unit 2. The X-rays that pass through the object W with the X-ray irradiation are detected by the sensor modules 102a and 101a.

  The sensor module 102 a converts X-rays that pass through the inspection object W into light by the scintillator 121. The light converted by the scintillator 121 is received by the light receiving element 123 that is a photodiode. Each light receiving element 123 converts the received light into an electrical signal and outputs it to the control unit 40 as first X-ray transmission data.

  The sensor module 101a receives X-rays that have not been converted into visible light by the sensor module 102a. The X-rays received by the sensor module 101a are converted into light by the scintillator 111 after the quality of the radiation is varied by the X-ray filter 110. The light converted by the scintillator 111 is received by the light receiving element 113 which is a photodiode. Each light receiving element 113 converts the received light into an electrical signal and outputs it to the control unit 40 as second X-ray transmission data.

  The light receiving elements 123 and 113 of the sensor modules 102a and 101a respectively output first X-ray transmission data and second X-ray transmission data corresponding to the X-ray dose transmitted through the inspection object W. The control unit 40 generates an X-ray transmission image composed of an image having a gray scale corresponding to the X-ray transmission data. The control unit 40 develops an image of the first X-ray transmission data output from the sensor module 102a and the second X-ray transmission data output from the sensor module 101a, and corresponds to both X-ray transmission data. An X-ray transmission image is obtained. And the control part 40 makes the density | concentration of a foreign material relatively dark by performing the superimposition (addition of a corresponding pixel value) of two X-ray transmission images, and emphasizes a foreign material with respect to the to-be-inspected object W, Foreign matter can be easily extracted. Note that the image processing of the control unit 40 is not limited to superimposition processing, and may be executed by difference (subtraction of corresponding pixel values) processing. For example, if the difference between one X-ray transmission image and the other X-ray transmission image is executed, the density of the inspection object W can be reduced while leaving the density of the foreign matter, and as a result, the overlapping (corresponding pixel value) The foreign matter can be emphasized in substantially the same manner as when adding.

  The two sensor modules 102a and 101a are arranged vertically based on a single X-ray. Thereby, the X-ray detection of the same location can be performed for the to-be-inspected object W conveyed on the conveyance part 2 at the same time with respect to the conveyance direction.

  Accordingly, there is no deviation in the transport direction between the X-ray transmission images in the sensor modules 102a and 101a. Therefore, the superimposition (or difference) processing of both image data in the control unit 40 can be easily executed, so that electrical delay processing for aligning both image data can be eliminated, and foreign matter can be easily detected. Can be extracted. Further, when the inspection object W is deformed during conveyance, both the X-ray transmission images are similarly deformed according to the deformation, so that the images can be aligned.

  Then, the control unit 40 determines whether or not there is a foreign substance in the inspection object W (including the surface) based on the X-ray transmission data after the image processing, and from this determination result, a non-defective product (no foreign substance) or A sorting signal indicating a defective product (with foreign matter) is output. After the inspection, the inspected object W is unloaded and sorted into a non-defective product and a defective product according to a sorting signal output from the control unit 40 by a subsequent sorting device or the like.

  Further, the X-ray detector 10 has a plurality of sensor modules 102a and 101a. However, since the X-ray generation unit 9 is single, the X-ray generation unit 9 and the X-ray detector 10 are different without being provided. Since the foreign matter detection based on the X-ray of the quality can be performed, the foreign matter detection can be performed while reducing the cost.

  A specific example of foreign object detection by the sensor modules 102a and 101a will be described. Since the sensor module 102a does not have the X-ray filter 110, it receives X-rays whose transmission amount is not attenuated, and outputs an electrical signal corresponding to the transmission amount of the X-rays to the control unit 40. The sensor module 101 a provided with the X-ray filter 110 receives X-rays whose transmission amount is attenuated and outputs an electrical signal corresponding to the transmission amount of the X-rays to the control unit 40.

  Specifically, what is detected as a foreign object in the inspected object W (including the surface) that is processed food should be originally from the processed food, such as bones and shells that were originally in the processed food. The case of a metal or the like without any of these may be considered. In this case, the X-ray transmission data output on the side of the sensor module 102a that receives the X-ray whose amount of transmission is not attenuated easily emphasizes the inspection object W that easily transmits X-rays, bones, shells, and the like. The X-ray filter 110 can attenuate the X-ray energy of only a predetermined band having a low X-ray energy among the X-rays generated from the X-ray generator 9 and can emphasize the shadow of a hard object in the foreign matter. Therefore, the X-ray transmission data on the sensor module 101a side that receives X-rays (that is, high X-ray energy) from which X-ray energy is deleted by the X-ray filter 110 is emphasized for metals that are difficult to transmit X-rays. become able to.

  As a result, the control unit 40 sets a plurality of threshold values corresponding to the desired type of foreign matter for both the X-ray transmission data from the sensor module 102a and the sensor module 101a, thereby inspecting the defective product as inspected. The foreign substance of the object W is only a bone or a shell (small foreign object or thin foreign object) or only a metal, or includes both a bone or a shell (small foreign object or thin foreign object) and a metal. This determination signal can be externally output in addition to the above-mentioned selection signals for good and defective products. For example, in the “ham” of food as the inspected object W, “bone”, “metal”, and the like may be mixed as the types of foreign matters.

  Therefore, in the X-ray inspection apparatus 1 described above, by having the sensor modules 102a and 101a that receive X-rays having different radiation qualities, foreign substances that easily transmit X-rays (such as bones and shells and small foreign substances or thin foreign substances) Since foreign substances (such as metal) that are difficult to transmit X-rays can be detected separately, it is possible to detect foreign substances with high accuracy without being limited to foreign objects to be detected. In addition, as described above, it is needless to say that the control unit 40 can perform extraction processing such as emphasizing a foreign object relative to the inspection object W by performing the above superposition or difference processing on both X-ray transmission images. Yes.

  In the above description, the X-ray filter 110 is provided in one sensor module 101a and the X-ray quality is changed. However, the X-ray filter 110 is not provided in the sensor module 101a, but is provided in the sensor modules 102a and 101a. The scintillators 121 and 111 may have different X-ray-light conversion characteristics. In this case, the sensor modules 102a and 101a can detect X-ray transmission amounts in different bands of X-rays, and different types of foreign matter can be used in each of the sensor modules 102a and 101a without using the X-ray filter 110. Can be detected. At the same time, the foreign matter can be emphasized relative to the inspection object W by superimposing the X-ray transmission image by the control unit 40 or by difference processing.

  As shown in FIG. 6, the X-ray detector 10 may include two sensor modules 103a and 101a arranged one above the other, and the visible light reflector 132 may be provided on the upper sensor module 103a. These sensor modules 103a and 101a are also arranged up and down so as to receive a single X-ray irradiated from the X-ray generation unit 9, as in the case of FIG.

  In FIG. 6, the lower sensor module 101 a is the same as described above, but the upper sensor module 103 a includes a scintillator 131, a visible light reflector 132, and a light receiving element 133. Similar to the light receiving element 113, the light receiving element 133 includes a plurality of photodiodes arranged in a line in the depth direction of the figure. The scintillator 131 and the visible light reflector 132 also have a predetermined length in the depth direction in the drawing along the arrangement of the light receiving elements 133. The visible light reflector 132 is composed of a total reflection mirror and is disposed at an angle of 45 degrees.

  In the above configuration, the sensor module 103a converts the X-rays transmitted through the inspection object W into light by the scintillator 131. The light converted by the scintillator 131 is reflected by the visible light reflector 132 in the horizontal direction orthogonal to 90 degrees and then received by the light receiving element 133. Each photodiode of the light receiving element 133 converts the received light into an electric signal and outputs it to the control unit 40. Since the light receiving element 133 is provided at a position that does not directly receive the X-rays emitted from the X-ray generation unit 9, the durability of the light receiving element 133 can be improved. The sensor module 101a receives X-rays that have not been converted into visible light by the sensor module 103a, and the light receiving element 113 of the sensor module 101a is a lower position that directly receives the X-rays of the X-ray generation unit 9. However, since the received X-rays themselves are attenuated through the X-ray filter 110, the durability of the light receiving element 113 can be improved.

  Further, in the sensor module 103a, the visible light reflector 132 is disposed below the scintillator 131 instead of the light receiving element 133, and the light converted by the scintillator 131 is reflected by the visible light reflector 132 in the horizontal direction orthogonal to 90 degrees. After that, since the light receiving element 133 receives light, the height of the sensor module 103a can be suppressed.

  As shown in FIG. 7, the X-ray detector 10 may be configured by providing three sensor modules 103a, 104a, and 101a. These sensor modules 103a, 104a, and 101a are also arranged vertically so as to receive a single X-ray irradiated from the X-ray generation unit 9, as in the case of FIG.

  In FIG. 7, the uppermost sensor module 103a and the lowermost sensor module 101a are the same as described above, but the sensor module 104a provided in the middle has a configuration in which the sensor module 101a and the sensor module 103a are combined. Yes. That is, the sensor module 104 a includes the X-ray filter 140, the scintillator 141, the visible light reflector 142, and the light receiving element 143. As the X-ray filters 140 and 110 provided in the intermediate sensor module 104a and the lowermost sensor module 101a, the X-ray filters 140 and 110 that change the X-ray quality are used differently. That is, the predetermined band of X-rays attenuated by the intermediate X-ray filter 140 is different from the predetermined band of X-rays attenuated by the lowermost X-ray filter 130.

  In the intermediate sensor module 104a, the quality of X-rays that have not been converted into visible light by the uppermost sensor module 103a is varied. In the lowermost sensor module 101a, the quality of X-rays that have not been converted into visible light by the uppermost sensor module 103a and the intermediate sensor module 104a is varied. As a result, the quality of X-rays received by the sensor modules 103a, 104a, and 101a are all made different.

  Thus, by arranging two or more stages of sensor modules 103a, 104a, 101a in a plurality of stages, the X-ray quality of each sensor module 103a, 104a, 101a differs, and correspondingly different types. The foreign object can be emphasized and detected. In the present invention, according to the lower sensor module 101a, the X-ray energy is attenuated so that soft foreign matter can be emphasized and detected. Even if the sensor modules 103a, 104a, 101a having two or more stages are provided in a plurality of stages as described above, since all of them receive a single X-ray, the inspection object W transporting the transport unit 2 is always provided. The same part can be detected simultaneously, and image processing in the control unit 40 can be easily performed.

  As described above, the X-ray detector 10 according to the present embodiment has a plurality of sensor modules 102a, 102b, 102c, which output first X-ray transmission data based on the intensity of incident X-rays. Sensor module group 102 (first sensor module group) including a plurality of sensor modules 101a, 101b, 101c,... That output second X-ray transmission data (second sensor) Module group), and the sensor module group 102 and the sensor module group 101 are arranged so as to overlap in the incident direction of incident X-rays, and each sensor of the sensor module group 102 Modules 102a, 102b, 102c,... And sensor modules 101a, 101b, 10 of the sensor module group 101 c,... are arranged in a line at a predetermined interval, and the predetermined interval is determined by the sensor modules 102a, 102b, 102c,... of the sensor module group 102 and the sensor modules 102a, 102b,. 102c,... In the sensor module group 101 corresponding to each of the sensor modules 101a, 101b, 101c,... It has been decided.

  For this reason, each direction which connected each sensor module which has the one-to-one correspondence between the sensor module group 102 (1st sensor module group) juxtaposed and the sensor module group 101 (2nd sensor module group), respectively. When the X-ray generation source is provided in the focusing region where the rays are focused, both X-rays incident from the same direction can be detected. For example, the X-ray transmitted through the upper sensor module 102c. The line enters the corresponding lower sensor module 101c, and the first X-ray transmission data output from the upper sensor modules 102a, 102b, 102c,... And the lower sensor modules 101a, 101b, 101c,. Can be prevented from being misaligned with the second X-ray transmission data output from. A foreign object can be detected with high sensitivity by performing arithmetic processing using the X-ray transmission data output from the X-ray detector 10.

  In addition, each direction line connects each corresponding point such as the midpoint or one end of each sensor module. For example, select which corresponding point is used according to the number of elements included in the sensor module. Good. That is, when the number of elements included in the module is large, as shown in FIG. 4A, the midpoints are set as corresponding points, so that the shift amount at both ends where the positional shift is maximum can be suppressed small. it can. On the other hand, when the number of elements included in each module is small and the amount of deviation at the other end is in an acceptable range, as shown in FIG. The arrangement of the sensor modules can be easily determined by the position of the end, and in any case, a sensor module group 102 (first sensor module group) and a sensor module group 101 (first sensor module group) each composed of a plurality of sensor modules. Misalignment between the first X-ray transmission data and the second X-ray transmission data respectively output from the second sensor module group).

  In addition, the X-ray inspection apparatus 1 according to the present embodiment is an X-ray detection apparatus that detects foreign matter in the inspection object W from the amount of X-rays transmitted to the inspection object W and transmitted through the inspection object W. 1 and an X-ray generator 9 that emits X-rays toward an area through which the inspection object W passes from an X-ray source, and an X-ray array arranged in a direction orthogonal to the conveyance direction of the inspection object W A plurality of sensor modules 102a, 102b, 102c, which receive X-rays irradiated from the generation unit 9 and pass through the inspection object W and output first X-ray transmission data based on the transmission amount of the X-rays. And a sensor module group 101 including a plurality of sensor modules 101a, 101b, 101c,... That output second X-ray transmission data, and the sensor module group 102 and the sensor module. Group 101 X-ray detector 10 juxtaposed along the direction in which X-rays are transmitted, first image data based on first X-ray transmission data, and second image data based on second X-ray transmission data, And a control unit 40 for detecting foreign matter in the inspection object W based on an image calculated using the sensor module, and a sensor module corresponding to each of the sensor modules 102a, 102b, 102c,. The sensor modules 101a, 101b, 101c,... In the group 101 are arranged at intervals determined based on the direction in which X-rays are transmitted.

  Therefore, the positions of the first X-ray transmission data from the upper sensor modules 102a, 102b, 102c,... And the second X-ray transmission data from the lower sensor modules 101a, 101b, 101c,. Misalignment can be prevented and foreign matter can be detected with high sensitivity.

  In the X-ray inspection apparatus 1 according to the present embodiment, the sensor modules 103a, 104a, and 101a are converted by the scintillators 131, 141, and 111 that convert X-rays into visible light, and the scintillators 131, 141, and 111, respectively. A plurality of light receiving elements 133, 143, and 113 that receive visible light and output X-ray transmission data corresponding to the amount of X-ray transmission, and exclude the lowest stage of the sensor modules 103 a, 104 a, and 101 a The sensor modules 103a and 104a have visible light reflectors 132 and 142 that reflect the visible light converted by the scintillators 131 and 141 in a direction different from the direction in which the X-ray from the X-ray generation unit 9 is transmitted. .

  For this reason, since the light receiving elements 133 and 143 can be disposed in the X-ray reflection direction by the visible light reflectors 132 and 142, the height of the sensor modules 103a, 104a, and 101a can be suppressed.

  Further, the X-ray inspection apparatus 1 according to the present embodiment includes a light receiving element 123 of each sensor module 102a, 102b, 102c,... Of the sensor module group 102 and each sensor module 101a, 101b, 101c of the sensor module group 101. ,... Are spaced apart from each other so that the X-ray transmission positions of the sensor modules 101a,. It is arranged.

  For this reason, the X-ray passage positions coincide with each other for the light receiving elements 123 and 113, and the positional deviation of the X-ray transmission data can be further prevented, and foreign matters can be detected with higher sensitivity.

  The embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. For example, with respect to the X-ray inspection apparatus 1 according to the present embodiment, X-rays are irradiated from above the inspection object W to be transported and transmitted through the inspection object W by the X-ray detector 10 disposed below the transport surface. The configuration for detecting the X-rays described above has been described. X-rays are irradiated from below, from the side or from the side of the inspection object W, and the inspection object W is placed by the X-ray detector 10 disposed at the opposite position. Needless to say, the transmitted X-rays may be detected and can be appropriately changed according to the shape of the inspection object W or the like.

  As described above, the X-ray inspection apparatus according to the present invention has the effect of preventing the positional deviation of X-ray transmission data from a plurality of sensor modules and detecting foreign matter with high sensitivity. The present invention is useful as an X-ray detector and an X-ray inspection apparatus that detect X-rays irradiated from a generator and transmitted through an inspection object.

DESCRIPTION OF SYMBOLS 1 X-ray inspection apparatus 2 Conveyance part 3 Detection part 4 Case 5 Display part 6 Drive motor 7 Carry-in entrance 8 Carry-out exit 9 X-ray generation part 10 X-ray detector 11 Box 12 X-ray tube 16 Shielding curtain 21 Conveyance path 22 Inspection space 40 Control unit 42 Storage unit 43 Image processing unit 44 Determination unit 45 Setting unit 101 Sensor module group (second sensor module group)
102 sensor module group (first sensor module group)
103, 104 sensor module group 101a, 101b, 101c, 102a, 102b, 102c, 103a, 103b, 103c, 104a, 104b, 104c sensor module 101ax, 101ay, 101bx, 101by, 101cx, 101cy, 102ax, 102ay, 102bx, 102by , 102cx, 102cy Corresponding point 111, 121, 131, 141 Scintillator 113, 123, 133, 143 Light receiving element 132, 142 Visible light reflector 150 Corresponding line W Inspected object

Claims (3)

An X-ray inspection apparatus (1) for detecting a foreign matter in the inspection object from an amount of X-rays transmitted to the inspection object (W) and transmitted through the inspection object,
An X-ray generator (9) that emits X-rays from an X-ray source toward a region through which the inspection object passes;
Based on the amount of X-rays transmitted, the X-rays are arranged together in a direction orthogonal to the conveyance direction of the inspection object, receive X-rays irradiated from the X-ray generation unit and transmitted through the inspection object, and The first sensor module group (102) including a plurality of sensor modules (102a, 102b, 102c,...) That output the radiation transmission data and the plurality of sensor modules (101a, 102a) that output the second X-ray transmission data. 101b, 101c, ...) including a second sensor module group (101), and the first sensor module group and the second sensor module group are in a direction in which the X-rays are transmitted. An X-ray detector (10) juxtaposed along,
Foreign matter in the object to be inspected based on an image calculated using the first image data based on the first X-ray transmission data and the second image data based on the second X-ray transmission data. A control unit for detecting,
The sensor modules of the second sensor module group corresponding to the sensor modules of the first sensor module group are arranged with an interval determined based on the transmission direction of the X-rays being separated from each other. A featured X-ray inspection device. The sensor module is
Scintillators (111, 121) for converting X-rays into visible light;
A plurality of light receiving elements (113, 123) that receive visible light converted by the scintillator and output X-ray transmission data corresponding to the amount of X-ray transmission;
The said 1st sensor module has a visible light reflector (132) which reflects the visible light after conversion with the said scintillator in the direction different from the direction through which the said X-ray | X_line permeate | transmits. X-ray inspection equipment. Each of the second sensor module groups is arranged such that the X-ray transmission positions of the light receiving elements of the sensor modules of the first sensor module group and the light receiving elements of the sensor modules of the second sensor module group coincide with each other. The X-ray inspection apparatus according to claim 1, wherein a plurality of light receiving elements of the sensor module are spaced apart from each other.

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