JP5860710B2 - X-ray inspection equipment - Google Patents

Description

  The present invention is an X-ray detector that is provided in a part of a production line and that irradiates X-rays from an X-ray generator to sequentially inspected objects, and detects X-rays transmitted through the object. The present invention relates to an X-ray inspection apparatus for inspecting a defect of an inspection object such as a foreign substance mixed into the inspection object based on a detection output, and in particular, which X-ray device of the X-ray generator or the X-ray detector has a poor performance. Relates to the technology to be identified

  X-ray inspection equipment irradiates X-rays on various types of inspection objects (raw meat, fish, processed foods, medicines, etc.) that are sequentially transferred on the transfer line, and transmits X-rays through the inspection objects. It is an apparatus for inspecting foreign substances such as metals, glass, stones, and bones contained in the object to be inspected, and missing parts in the object to be inspected based on the amount.

  As a conventional X-ray inspection apparatus of this type, for example, an X-ray generator for generating X-rays by causing thermal electrons from a cathode filament of an X-ray tube to collide with an anode target by a high voltage between the cathode and anode. And an X-ray detector comprising an array-shaped line sensor that converts X-rays into light by a scintillator and converts the converted light into electric signals in an inspection space irradiated with X-rays The X-ray inspection unit that detects the amount of X-ray transmitted through the inspection object is configured for the inspection object that passes through the inspection object.

  The X-ray tube or X-ray detector of the X-ray generator that constitutes the X-ray inspection unit has a lifetime, and the X-ray device is exchanged for the X-ray generator or the X-ray detector of the X-ray detector. Maintenance work is being performed. This maintenance work is performed with reference to the energization time to the X-ray generator. (For example, see Patent Document 1)

  In addition, regarding the X-ray detector, utilizing the tendency that the dark current of the photodiode of the line sensor (current output even when not receiving light) increases with the X-ray irradiation time due to damage caused by the X-ray irradiation, Maintenance work is performed in which the actual deterioration state of the line sensor is determined by a change in the dark current of the photodiode to predict the life of the line sensor. (See Patent Document 2)

JP 2004-144572 A JP 2002-168806 A

  However, the X-ray generator and the X-ray detector may not be able to obtain the sensitivity of the X-ray transmission amount necessary for the X-ray inspection due to some factor apart from the lifetime. In that case, for example, only the change in the dark current of the photodiode of the line sensor of the above-mentioned X-ray detector can specify whether the cause is due to the poor performance of the X-ray generator or the poor performance of the X-ray detector. First of all, in order to carry out the inspection normally, it was necessary to replace one by one in turn or both at once.

  Therefore, the present invention has been made in view of the above problems, and when X-rays are generated under predetermined conditions for the X-ray generator, a desired detection output cannot be obtained from the X-ray detector. In this case, an object of the present invention is to provide an X-ray foreign object detection device that can identify whether the failure is due to poor X-ray generator performance or poor X-ray detector performance.

   In order to solve the above-described problem, an X-ray inspection apparatus 1 according to claim 1 includes an X-ray generator 5 that generates X-rays that irradiate an inspection object conveyed on a conveyance path, and the inspection object. The X-ray detector 7 that converts the X-rays transmitted through the X-ray into an electric signal and outputs an X-ray detection signal, and the X-ray detection signal output from the X-ray detector determines the quality of the inspection object In the X-ray inspection apparatus including the pass / fail judgment unit 22, the reference is so set that the irradiated X-ray does not reach the reference region formed on a part of the detection surface of the X-ray received by the X-ray detector. A shielding member 12 provided so as to shield the region so as to be unshieldable, and the X-ray detector that outputs X-rays when the X-ray generator is generated under a predetermined condition; The first X-ray detection signal in the inspection area and the shielding member And a performance failure determination means 24 for determining whether or not at least one of the X-ray generator or the X-ray detector has a performance failure based on a second X-ray detection signal in the reference region for which the cancellation of the operation is performed. It is characterized by that.

  In this X-ray inspection apparatus, an X-ray generator or an X-ray detector is based on an X-ray detection signal corresponding to the reference region when the shielding is released and an X-ray detection signal corresponding to the inspection region outside the reference region. At least one of the performance failures is determined. Therefore, the X-ray detection signal in the reference region can be used as a reference value for the initial quality of the X-ray detector that is not damaged by the X-ray irradiation. The magnitude of this reference value and the reference value and the object to be inspected It is possible to determine whether or not at least one of the X-ray generator and the X-ray detector has a poor performance from the comparison with the X-ray detection signal of the inspection region that has been damaged by X-ray irradiation. become.

  The X-ray inspection apparatus according to claim 2 is the X-ray inspection apparatus according to claim 1, wherein the poor performance determination unit is configured to calculate the X-ray from the first X-ray detection signal and the second X-ray detection signal. A first X-ray detection amount obtained by subtracting an X-ray detection signal output from the X-ray detector when the X-ray generator is not generating X-rays and excluding an offset amount of the X-ray detector; A second X-ray detection amount is calculated, and when the second X-ray detection amount is less than a predetermined threshold, it is determined that the X-ray generator has poor performance, and the first X-ray detection amount And the second X-ray detection amount exceeds a predetermined detection amount difference, the X-ray detector is determined to have a poor performance.

  Accordingly, since the determination is made using the X-ray detection amount obtained by subtracting the offset amount output in a state where X-rays are not irradiated from the X-ray detection signal, the offset amount due to a temperature change such as dark current due to the semiconductor portion. The effects of fluctuations can be removed. In addition, when the X-ray detector is an indirect conversion method using a scintillator, the X-ray detector is defective due to a performance defect such as deterioration of the conversion efficiency of the scintillator excluding the photodiode which is a semiconductor portion, and the X-ray generator. Can be easily determined without being affected by the offset of the X-ray detector.

  The X-ray inspection apparatus according to claim 3 is the X-ray inspection apparatus according to claim 1 or 2, wherein the performance failure determination unit is configured to detect the X-ray when the X-ray generator does not generate X-rays. A first offset amount in the inspection region and a second offset amount in the reference region of the X-ray detector are acquired from an X-ray detection signal output from the detector, and the first offset amount and the second offset amount are acquired. The X-ray detector is determined to have a poor performance when the difference in offset amount exceeds a predetermined offset difference.

  As a result, the offset output in the state where X-rays such as dark current from the semiconductor portion of the X-ray detector are not irradiated is also determined, so the X-ray detector performance failure due to performance failure such as deterioration of the semiconductor portion is determined. can do.

  An X-ray inspection apparatus according to a fourth aspect of the present invention is the X-ray inspection apparatus according to any one of the first to third aspects, wherein the X-ray detector is one in which a plurality of X-ray detection elements are linearly arranged. It consists of a line sensor, The said shielding member shields a part of said line sensor, It is characterized by the above-mentioned.

  Thereby, for example, the line sensor can be effectively used when the width in the detection direction of the quality determination inspection of the inspection object is narrow.

  The X-ray inspection apparatus according to claim 5 is the X-ray inspection apparatus according to any one of claims 1 to 4, wherein the X-ray generator is disposed below the transport surface so as to sandwich the transport surface of the transport path. The X-ray detectors are arranged to face each other, and the shielding member is disposed above the transport surface so as to be capable of releasing the shielding.

  Thereby, since the shielding member is disposed in the space in which the inspection object is transported on the transport surface of the transport path, it is possible to easily shield and release the shielding from the reference region by the shielding member.

  The X-ray inspection apparatus according to claim 6 is output from the X-ray detector in the X-ray inspection apparatus according to any one of claims 1 to 5 in a normal operation for determining pass / fail of the inspection object. When the X-ray detection signal in the reference region is equal to or greater than a predetermined threshold, it is determined that the shielding by the shielding member is released, and the X-ray irradiation from the X-ray generator is temporarily stopped and the shielding member It is characterized by having a shielding abnormality control means 25 for informing that this is a shielding abnormality.

  With this configuration, in the case of normal operation for determining the quality of an object to be inspected, a part of the X-ray detector corresponding to the reference region in the X-ray detector even if there is a mistake in manually placing the shielding member in the reference region Can protect the area.

  An X-ray inspection apparatus according to a seventh aspect of the present invention is the X-ray inspection apparatus according to any one of the first to fifth aspects, wherein the X-ray inspection apparatus includes an actuator that moves the shielding member by electrical control, and the shielding can be released by the actuator. It is characterized by being.

  With this configuration, it is possible to dispose the shielding member in the reference region or cancel the shielding without human intervention.

  According to the present invention, when X-rays are generated for the X-ray generator under a predetermined condition, when a desired detection output cannot be obtained from the X-ray detector, this is a poor performance of the X-ray generator. Can be identified due to poor performance of X-ray detector

1 is a block diagram schematically showing the configuration of an X-ray inspection apparatus according to a first embodiment of the present invention. It is a perspective view which shows the structure of the conveyance means and X-ray inspection part of the X-ray inspection apparatus which concern on 1st Embodiment of this invention. (A) is a side view which shows arrangement | positioning of the shielding member of the X-ray inspection apparatus which concerns on 1st Embodiment of this invention. (B), (c) is each top view which shows the example of arrangement | positioning of the shielding member. It is a flowchart which shows the outline flow of the performance defect determination in the X-ray inspection apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the outline flow of the other performance defect determination in the X-ray inspection apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows arrangement | positioning of the shielding member of the X-ray inspection apparatus which concerns on 2nd Embodiment of this invention. (A), (b) is a figure which shows the example of the actuator of the X-ray inspection apparatus which concerns on 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  1. First Embodiment (FIG. 1) FIG. 1 is a diagram showing a first embodiment of the present invention. First, the configuration will be described.

  As shown in FIG. 1, the X-ray inspection apparatus 1 includes a transport unit 2, an X-ray inspection unit 4, a control unit 20, an operation unit 30, and a display unit 31.

  The X-ray inspection apparatus 1 is incorporated in a production line (not shown) through which an inspection object W to be inspected such as raw meat, fish, processed food, and medicine is conveyed, and irradiates the inspection object W with X-rays. In this apparatus, foreign matter contained in the inspection object W, missing parts of the inspection object W, etc. are inspected based on the amount of X-rays transmitted through the inspection object W.

  The conveyance unit 2 sequentially conveys the inspection object W on the conveyance path and passes the inspection object W through the X-ray inspection unit 4. As shown in FIG. 1, the inspection object W is conveyed in the direction of the arrow in FIG. 1 by an endless conveyance belt 3 wound around rollers arranged in the front and rear of the conveyance direction. The rollers are rotationally driven in synchronization by the non-conveying drive mechanism so that the inspection object W is conveyed at a predetermined constant conveying speed.

  The X-ray inspection unit 4 includes an X-ray generator 5 and an X-ray detector 7. Further, a shielding member 12 that shields a part of the detection surface of the X-ray detector is provided between the X-ray generator 5 and the X-ray detector 7.

  As shown in FIG. 2, the X-ray generator 5 has a configuration in which a cylindrical X-ray tube 6 provided inside a metal box is immersed in insulating oil (not shown). Thermionic electrons from the filament collide with the anode target by a high voltage between the cathode and anode to generate X-rays. The X-ray tube 6 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 6 are irradiated toward the lower X-ray detector 7 so as to cross the transport direction (X direction) in a substantially triangular screen shape by a slit (not shown). It is like that.

  In the X-ray generator 5 having such a configuration, the intensity of the X-ray generated by the X-ray tube 6 changes in proportion to the current (tube current) flowing between the anode and the cathode of the X-ray tube 6. The wavelength of the generated X-ray becomes shorter according to the voltage (tube voltage) applied between the anode and the cathode of the X-ray tube 6 and the transmission power becomes stronger. Therefore, X-rays having a desired quality can be generated by setting the tube current and tube voltage to the X-ray tube 6.

  As shown in FIG. 2, the X-ray detector 7 is provided below the transport surface so as to face the X-ray generation unit 3 so as to sandwich the transport surface of the transport path by the transport unit 2. Consists of an array line sensor in which elements (X-ray detection elements) for detecting a plurality of X-rays are arranged in a straight line in the Y direction orthogonal to the conveyance direction X of the object W to be inspected on the X-ray irradiation area plane. Is done. The line sensor includes a plurality of photodiodes 11 arranged in a line and a scintillator 10 provided on the line photodiode 11 as shown in FIG. The X-ray transmitted through the inspection object W in response to the X-ray irradiation to the object W is received by the scintillator 10 and converted into light, and the converted light is received by the corresponding photodiode, and the received light. Is converted into an electrical signal, and an X-ray detection signal is output as X-ray density data (X-ray transmission amount) for each line.

That is, the X-ray detector 7 outputs an electric signal having a level corresponding to the intensity of the received X-ray, and a plurality of elements arranged in a straight line in the Y direction are used as one line for each element. X-rays transmitted through the inspection object W are detected, and X-rays detected by each element are used as X-ray density data for one line, and output is sequentially repeated for each line as the inspection object W is conveyed.

  When the X-ray generator 5 does not irradiate X-rays, it is not converted into light by the scintillator 10 of the X-ray detector 7, so that the offset of the X-ray detector 7 is used as the offset amount of the photodiode 11 of the X-ray detector 7. An electric signal corresponding to the dark current is output.

  Moreover, the X-ray detector 7 by such a structure is accommodated in the X-ray detector accommodating unit 13 which is a metal box. The X-ray detector storage unit 13 has a slit 14 on the upper surface formed substantially flat. The slit 14 allows X-rays to pass through a long hole drilled so that the upper surface plate extends in the Y direction so that the detection surface on which the scintillators 10 arranged in a line receive X-rays is not shielded from X-rays. The resin material is waterproofed and attached with a silicon material or the like.

  The shielding member 12 provides a reference region for obtaining a reference value of an initial quality in an X-ray detector that is not damaged by X-ray irradiation during a normal operation for inspecting a defect of the inspection object. A part of the detection surface that receives the X-rays of the X-ray detector 7 is shielded so as to be formed on the detection surface. As shown in FIGS. 3A and 3B, the shielding member 12 shields a part of the slit 14 of the X-ray detection unit 13 by X-rays. As a result, the X-ray detector 7 forms a reference region that does not receive X-rays on a part of the detection surface. Then, the X-ray is irradiated with the first X-ray detection unit 8 that receives the X-ray and outputs a corresponding electrical signal by setting the detection surface outside the reference region and the detection surface as the reference region. It is divided into a second X-ray detector 9 that is shielded immediately and outputs an electrical signal corresponding to the dark current of the photodiode 11.

  The X-ray shielding by the shielding member 12 shields the trajectory through which the X-ray passes between the X-ray generator 5 and the scintillator 10 so that the X-ray irradiated to a part of the scintillator 10 does not reach. In this embodiment, by blocking a part of the detection surface of the X-ray detector 7, X-rays directed to a partial area of the scintillator 10 are blocked and a partial area of the scintillator emits X-rays. It is not to receive. Then, a shielding member 12 is screwed from above the conveyor belt 3 to the conveyor 2 or a stay fixed on the side surface of the conveyor 2 to shield a part of the detection surface of the X-ray detector 7.

  In the present embodiment, the X-ray detector 7 is composed of one line sensor, and a shielding member is formed so that a reference region is formed at a corner in a detection width direction (a direction orthogonal to the conveyance direction), which is a part of the line sensor. However, as shown in FIG. 3C, a shielding line sensor is provided separately from the line sensor for X-ray inspection, and is parallel in the vicinity of the line sensor for X-ray inspection. They may be arranged side by side. In this case, the line sensor can be replaced due to poor performance by replacing only the line sensor for X-ray inspection.

  The operation unit 30 includes a plurality of keys, switches, and the like that are operated for setting and instructions. The operation unit 30 performs setting operation of the type of the inspection object W to be conveyed by the conveyance unit 2, detection of foreign matter on the inspection object W, Various setting operations and instruction operations for missing item inspection are performed. In addition, the operation unit 30 performs an operation of switching between a normal operation mode for performing pass / fail determination (defective inspection) of the inspection object and a failure determination mode for determining poor performance of the X-ray equipment as the operation mode of the apparatus operation. To do.

  The display unit 31 includes, for example, a liquid crystal display and the like, a setting value when a setting operation for the type of the inspection object W is performed, a setting value regarding switching of an operation mode, and an instruction value when an instruction operation is performed. Various displays such as pass / fail judgment results are performed. Further, the display unit 31 displays an X-ray device (X-ray generator, X-ray detector) having a poor performance as a result determined by the poor performance determination means 24.

  The control unit 20 controls the entire X-ray inspection apparatus 1, and includes signal processing and control including various inspection processes based on the X-ray detection signal (X-ray density data) output from the X-ray detector 7. As shown in FIG. 1, the signal processing means 21, the pass / fail judgment means 22, the storage means 23, the performance failure judgment means 25, and the shielding abnormality control means 26 are provided.

  The signal processing means 21 generates an X-ray image based on the X-ray detection signal output from the X-ray detector 7, and further displays a foreign substance enhanced image that emphasizes the foreign substance in the inspection object W. It is generated as a determination image.

  The X-ray image has a large absorption amount, for example, by converting the X-ray density data from the X-ray detector 7 into data indicating the X-ray absorption amount absorbed by the inspection object W, such as logarithmic conversion. The image is generated so that the image has a higher density.

  In addition, the X-ray determination image generates an image that is subjected to a predetermined filter process on the X-ray image of the inspection object W to more easily emphasize and extract the foreign object information to be detected. In this filter processing, for example, a feature extraction filter such as a differential filter (Roberts filter, Prewitt filter, Sobel filter) or a Laplacian filter is used. As a result, the entire image is emphasized to facilitate edge detection, and foreign object information to be detected is further emphasized.

  The pass / fail judgment means 22 includes foreign matter in the inspection object W based on the X-ray judgment image (foreign matter emphasized image) generated by the signal processing means 21 from the X-ray detection signal output from the X-ray detector 7. In addition, the quality is determined such as whether or not it has been determined, and the determination result is displayed on the display unit 31.

  The storage means 23 stores the inspection conditions used for the inspection of the inspection object W for each product type. Further, the X-ray output condition (tube current and tube voltage) of the X-ray generator 5 at the time of determination by the performance failure determination means 24 and each threshold value for determination are stored.

  The performance failure determination means 24 is an inspection that is output from the X-ray detector 7 when X-rays are generated by setting the tube current and the tube voltage, which are the X-ray output conditions of the X-ray generator 5, with predetermined settings. X-ray generator 5 or X-ray detector 7 based on the X-ray detection signal (first X-ray detection signal) in the region and the X-ray detection signal (second X-ray detection signal) in the unshielded reference region At least one of the performance failures is determined. Specifically, when the operation mode is the operation mode, the second X-ray detection signal in the reference region that does not receive X-rays by the shielding member 12 and is less deteriorated by the effect of X-ray irradiation must satisfy a predetermined reference value. If the output from the X-ray generator 5 is weak, it is determined that the X-ray generator 5 has poor performance, and is used for the inspection of the second X-ray detection signal in the reference region and the inspection object. If the difference between the inspection area and the first X-ray detection signal exceeds a predetermined reference difference, the X-ray detector 7 that outputs the first X-ray detection signal of the inspection area is degraded due to deterioration or the like. Therefore, it is determined that the X-ray detector 7 has poor performance.

  In order to determine the poor performance, a value obtained by subtracting the X-ray detection signal output from the X-ray detector 7 when the X-ray generator 5 does not generate X-rays from the X-ray detection signal, that is, The determination may be made using the X-ray detection amount excluding the offset amount of the X-ray detector. In this case, the offset amount of the X-ray detector 7 is caused by the dark current of the photodiode 11 that is output when the X-ray detector 7 does not detect X-rays. It can be determined that the performance failure of the X-ray detector 7 at the time of the determination is due to a performance failure such as deterioration of the conversion efficiency of the scintillator 10.

  Further, in order to judge the performance failure, the offset amount of the X-ray detector (the X-ray detection signal output from the X-ray detector 7 when the X-ray generator 5 does not generate X-rays) is inspected. If the first offset amount of the region is compared with the second offset amount of the reference region and the difference exceeds a predetermined offset difference, the first X used for the inspection of the inspection object is further provided. It may be determined that the X-ray detector that outputs the line detection signal does not satisfy the performance and determines that the X-ray detector 7 has poor performance. In this case, since the offset amount of the X-ray detector 7 is due to the dark current of the photodiode 11, the poor performance of the X-ray detector 7 when judged using the detected amount of X-ray is the photodiode. 11 and the like due to poor performance such as deterioration.

  The shielding abnormality control means 25 starts from the X-ray detector 7 when X-ray irradiation starts from the X-ray generator 5 in the normal operation mode in which the operation mode of the apparatus determines the quality of the inspection object W. When the output X-ray detection signal in the reference region (the X-ray detection signal output from the X-ray detection unit 9 corresponding to the reference region of the X-ray detector 7) is equal to or greater than a predetermined threshold, the shielding member 12 is shielded. It is determined that it is released, the power supply to the X-ray generator 5 is cut off, the X-ray irradiation from the X-ray generator 5 is temporarily stopped, and the shielding unit 12 indicates that the shielding is abnormal. To be displayed.

  As a result, when the operation mode is switched from the failure determination mode to the operation mode and the pass / fail determination of the inspection object is performed, the reference due to the operator forgetting to return the shielding member 12 removed from the reference region in the failure determination mode. Even if there is an arrangement error in the area, a part of the X-ray detector corresponding to the reference area can be protected. The X-ray irradiation is temporarily stopped by applying a voltage not higher than the voltage at which the X-ray tube 6 does not generate X-rays to the X-ray tube 6 without interrupting the power supply. You may do it. Moreover, you may make it alert | report by outputting to the exterior the signal which shows that it is shielding abnormality.

  Next, in the X-ray inspection apparatus 1 of this embodiment, the shielding member 12 is moved from the reference region, the shielding is released, and the performance failure determination performed after the operation mode of the apparatus operation is switched to the failure determination mode. The operation will be described. FIG. 4 is a flowchart showing a general flow of determining performance failure using the X-ray detection output.

  First, X-ray irradiation is started by making predetermined settings for the tube current and tube voltage, which are the X-ray output conditions of the X-ray generator 5 (step S10). At this time, the X-rays output from the X-ray detector 7 With respect to the detection signal, a first X-ray detection signal D1 that is an X-ray detection signal in the examination region and a second X-ray detection signal D2 that is an X-ray detection signal in the unshielded reference region are acquired (step S11). . At this time, the first X-ray detection signal D1 and the second X-ray detection signal D2 are output from the X-ray detector 7 with a predetermined number of lines for each element, or within a predetermined range. Get the average of each. And X-ray irradiation is stopped (step S12).

  Next, the second X-ray detection signal D2 in the reference region is compared with a predetermined reference value J1 (step S13). If the X-ray detection signal D2 is less than the reference value J1 (if step S13 is YES), X It is determined that the line generator has poor performance (step S14).

  Next, the difference between the first X-ray detection signal D1 in the inspection area and the second X-ray detection signal D2 in the reference area is compared with a predetermined reference difference value J2 (step S15). If the reference difference value J2 is exceeded (if step S15 is YES), it is determined that the X-ray detector has a poor performance (step S16).

  As described above, which X-ray apparatus has a poor performance by using the X-ray detection signal of the reference region and the inspection region whose shielding is released when the X-ray generator generates X-rays under a predetermined condition. The X-ray equipment to be replaced is determined by determining whether or not.

  Next, another performance failure determination operation of the X-ray inspection apparatus of the present embodiment will be described. FIG. 5 is a flowchart showing a general flow of determining performance failure using the X-ray detection amount obtained by removing the offset amount of the X-ray detector from the X-ray detection signal.

  First, regarding the X-ray detection signal as the offset amount of the X-ray detector 7 output from the X-ray detector 7 in a state where X-ray irradiation is stopped, the first offset amount Z1 in the examination region and the reference region The second offset amount Z2 at is acquired (step S20). At this time, the first offset amount Z1 and the second offset amount Z2 averaged the output values of the predetermined number of lines of each element output from the X-ray detector 7 in all the regions or in a predetermined range, respectively. Get things.

  Next, X-ray irradiation is started by making predetermined settings for the tube current and tube voltage, which are the X-ray output conditions of the X-ray generator 5 (step S21). At this time, the X-rays output from the X-ray detector 7 With respect to the detection signal, a first X-ray detection signal D1 that is an X-ray detection signal in the examination region and a second X-ray detection signal D2 that is an X-ray detection signal in the unshielded reference region are acquired (step S22). . At this time, the first X-ray detection signal D1 and the second X-ray detection signal D2 are output from the X-ray detector 7 with a predetermined number of lines for each element, or within a predetermined range. Get the average of each. Then, the X-ray irradiation is stopped (step S23).

  Next, the first X-ray detection amount M1 (D1-Z1) and the second X-ray detection amount M2 (D2-Z2) are calculated by subtracting the offset signal from the acquired X-ray detection signal (step S24).

  Next, the second X-ray detection amount M2 in the reference region is compared with a predetermined reference detection amount J3 (threshold) (step S25). If the X-ray detection amount M2 is less than the reference detection amount J3 (YES in step S25). ), It is determined that the X-ray generator has poor performance (step S26).

  Next, the difference between the first X-ray detection amount M1 in the examination region and the second X-ray detection amount M2 in the reference region is compared with a predetermined reference difference value J4 (detection amount difference) (step S27). If the measured value exceeds the predetermined reference difference value J4 (when step S27 is YES), it is determined that the X-ray detector has a poor performance (step S28).

  Next, the difference between the first X-ray detection signal Z1 in the inspection region and the second X-ray detection signal Z2 in the reference region is compared with a predetermined reference difference value J5 (offset difference) (step S29). If the value exceeds the predetermined reference difference value J5 (when step S29 is YES), it is determined that the X-ray detector has a poor performance (step S30).

  As described above, which X-ray apparatus has a poor performance by using the X-ray detection amount of the reference region and the inspection region whose shielding is released when the X-ray generator generates X-rays under a predetermined condition. The X-ray equipment to be replaced is determined by determining whether or not.

  As described above, the X-ray inspection apparatus 1 according to the present embodiment has passed through the inspection object W and the X-ray generator 5 that generates X-rays that irradiate the inspection object conveyed on the conveyance path. An X-ray detector 7 that converts an X-ray into an electrical signal and outputs an X-ray detection signal, and a pass / fail determination means that determines pass / fail of the object W based on the X-ray detection signal output from the X-ray detector 7 22 in the X-ray inspection apparatus 1, the reference area is set so that the irradiated X-rays do not reach the reference area formed on a part of the X-ray detection surface received by the X-ray detector 7. A shielding member 12 provided so as to be shielded so as to be able to be shielded, and an inspection region that is output from the X-ray detector 7 when X-rays are generated from the X-ray generator under a predetermined condition and that is out of the reference region In the reference region where the shielding by the first X-ray detection signal and the shielding member 12 is released Kicking is a determining poor performance determining means 24 at least one of the poor performance of the X-ray generator or X-ray detector based on the second X-ray detection signals, comprising the.

  With this configuration, the X-ray detection signal of the reference area can be used as the reference value at the initial stage of irradiation, and the X-ray generation is based on the magnitude of this reference value and the comparison between this reference value and the X-ray detection signal of the inspection area that is not shielded It is possible to determine whether at least one of the detector and the X-ray detector has a poor performance.

  Further, in the X-ray inspection apparatus 1 according to the present embodiment, the X-ray detection signal in the reference region output from the X-ray detector 7 is a predetermined threshold value in the normal operation for determining pass / fail of the inspection object W. At this time, it is determined that the shielding by the shielding member is released, the X-ray irradiation from the X-ray generator 5 is temporarily stopped, and the shielding abnormality control means for notifying that the shielding member 12 is shielded abnormally 25.

  With this configuration, it is possible to protect a partial region of the X-ray detector corresponding to the reference region in the X-ray detector 7 even if the shielding member is manually disposed in the reference region.

  Although the X-ray detector 7 has been described with respect to an indirect conversion type line sensor using a scintillator and a photodiode, a semiconductor sensor using a direct conversion type X-ray conversion film may be used. Needless to say, the same effect can be obtained even if the X-ray detector 7 is not a line sensor but an area sensor.

2. Second Embodiment The X-ray inspection apparatus 1 of the present example is different from the first embodiment in that it includes an actuator 14 that moves the shielding member 12 by electrical control. Since the configuration of the first embodiment is the same as that of the first embodiment, only the portions different from the configuration of the first embodiment will be described. Regarding the other configurations, the portions corresponding to the configurations of the first embodiment are the same as those of the first embodiment. The same reference numerals are attached, and the description of the first embodiment is appropriately incorporated within a consistent range, and the description thereof is omitted.

  In the present embodiment, as shown in FIG. 6, an actuator 15 that moves the shielding member 12 is provided. The actuator 15 is configured so that the shielding member 12 shields the reference area in a normal state (power OFF), and when performing a performance failure determination of the X-ray equipment, the actuator 15 is activated to release the shielding of the reference area. When the performance defect determination of the X-ray device is completed, the control unit 20 controls the operation region of the actuator 15 so as to return to the original position and shield the reference region.

  Specifically, for example, after the operation mode of the apparatus operation is switched to the failure determination mode according to an instruction from the operation unit 30, the control unit 20 operates the actuator 15 to release the shielding of the reference region, resulting in poor performance. A performance failure determination process by the determination means 24 is performed. When the performance failure determination process is completed, the control unit 20 restores the operating portion of the actuator 15 to shield the reference region, the determination result is displayed on the display unit 31, and the operation mode is normally changed from the failure determination mode. Switch to the operation mode of operation.

  As the actuator 15, a stepping motor 15 a or the like is used as shown in FIG. 7A, and the shielding member 12 is moved by a required movement amount according to the rotation angle and the rotation speed of the motor. Then, the shielding member 12 is slid in the transport direction or in a direction orthogonal to the transport direction along the guide member (not shown) by the operation of the actuator 15 to release the shielding of the reference region.

  Further, as shown in FIG. 7B, the actuator 15 uses a cylinder 15b or the like to slide the shielding covering member 12 in the transport direction or in a direction perpendicular to the transport direction to release the shielding of the reference area. May be.

  The shielding member 12 may be provided above the transport conveyor in the same manner as in the first embodiment, and the actuator 15 may be operated. However, as shown in FIG. It may be arranged in 13. If the actuator 15 and the shielding member 12 are arranged in the X-ray detector storage unit 13 in this way, a stay or the like for attaching the shielding member 12 and the actuator 14 to the side surface of the transport unit 2 or the like becomes unnecessary. The safety and cleanability of the conveyance path through which the inspection object is conveyed can be improved.

  In addition, when the actuator 15 is provided in this way, since the movement of the shielding member 12 is controlled when determining poor performance of the X-ray equipment, the operation mode of the apparatus is the inspection object W. In the normal operation mode in which pass / fail judgment is performed, the shielding member 12 always shields the reference region, and the shielding abnormality control means 25 in the configuration of the first embodiment can be dispensed with.

  As described above, the radiation examination apparatus 1 according to the second embodiment of the present invention is characterized by including the actuator 15 that moves the shielding member 12, and the shielding member 12 can be moved to the reference region without human intervention. Can be placed or unshielded.

  As described above, the X-ray inspection apparatus of the present invention converts an X-ray into an electrical signal and outputs an X-ray detection signal when the X-ray generator generates X-rays under a predetermined condition. Since the X-ray generator or the X-ray detector has a poor performance based on the X-ray detection signal in the inspection region and the X-ray detection signal in the reference region where the shielding by the shielding member is released, which is output from the X-ray detector. It is useful for an X-ray inspection apparatus and an X-ray mass measurement apparatus using an X-ray detector.

DESCRIPTION OF SYMBOLS 1 ... X-ray inspection apparatus 2 ... Conveyance part 4 ... X-ray inspection part 5 ... X-ray generator 7 ... X-ray detector 10 ... Scintillator 11 ... Photodiode 12 ... Shielding member 13 ... X-ray detector storage unit 14 ... Slit DESCRIPTION OF SYMBOLS 15 ... Actuator 20 ... Control part 21 ... Signal processing means 22 ... Pass / fail judgment means 23 ... Storage means 24 ... Performance defect judgment means 25 ... Shielding abnormality control means 30 ... Operation part 31 ... Display part

Claims (7)

An X-ray generator (5) for generating X-rays to irradiate the inspection object conveyed on the conveyance path, and X-rays transmitted through the inspection object are converted into electric signals and an X-ray detection signal is output. In an X-ray inspection apparatus comprising: a line detector (7); and a pass / fail judgment means (22) for judging pass / fail of the inspection object based on an X-ray detection signal output from the X-ray detector.
Provided to shield the reference area so that the X-ray irradiated does not reach the reference area formed on a part of the X-ray detection surface received by the X-ray detector. A shielding member (12);
The first X-ray detection signal output from the X-ray detector when X-rays are generated from the X-ray generator under a predetermined condition and shielded by the shielding member in the examination region outside the reference region A performance failure determination means (24) for determining whether or not at least one of the X-ray generator or the X-ray detector is a performance failure based on a second X-ray detection signal in the reference region that has been released. An X-ray inspection apparatus comprising:   The poor performance determination means is an X-ray output from the X-ray detector when the X-ray generator is not generating X-rays from the first X-ray detection signal and the second X-ray detection signal. The first X-ray detection amount and the second X-ray detection amount are calculated by subtracting the detection signals and excluding the offset amount of the X-ray detector, and the second X-ray detection amount is a predetermined threshold value. When the X-ray generator determines that the performance of the X-ray generator is poor and the difference between the first X-ray detection amount and the second X-ray detection amount exceeds a predetermined detection amount difference, The X-ray inspection apparatus according to claim 1, wherein the X-ray detector determines that the performance is poor.   The performance failure determination means is configured to detect a first offset amount in the inspection region of the X-ray detector from an X-ray detection signal output by the X-ray detector when the X-ray generator does not generate X-rays. And when the difference between the first offset amount and the second offset amount exceeds a predetermined offset difference, the X-ray detector has a poor performance. The X-ray inspection apparatus according to claim 1, wherein the determination is performed.   The X-ray detector includes a single line sensor in which a plurality of X-ray detection elements are linearly arranged, and the shielding member shields a part of the line sensor. X-ray inspection apparatus in any one of. The X-ray detector is disposed below the transfer surface so as to face the X-ray generator so as to sandwich the transfer surface of the transfer path, and the shielding member is disposed above the transfer surface so that the shielding can be released. The X-ray inspection apparatus according to claim 1, wherein the X-ray inspection apparatus is provided.   In a normal operation for determining pass / fail of the inspection object, the shielding by the shielding member is released when the X-ray detection signal in the reference region output from the X-ray detector is equal to or greater than a predetermined threshold. And a shielding abnormality control means (25) for notifying that the shielding member is abnormally shielded while temporarily suspending X-ray irradiation from the X-ray generator. The X-ray inspection apparatus according to any one of 5. 6. The X-ray inspection apparatus according to claim 1, further comprising an actuator (15) for moving the shielding member by electrical control, wherein the shielding can be released by the actuator.

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