JP2010210409A - X-ray foreign matter detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray foreign matter detector for reliably detecting foreign matter even when foreign matter has mixed in a thin part of an object to be inspected and also when foreign matter has mixed in a thick part by heightening the contrast between the object to be inspected and the foreign matter without a loss of shading information due to the saturation of output from an X-ray detector even when the output of X-rays is strengthened. <P>SOLUTION: The X-ray foreign matter detector includes: an X-ray detector 10 for performing the detection and output of photodiodes 30b by the first base scanning during a storage time (t/2 storage time) corresponding to a prescribed scanning period Ts, performing detection and output by the second base scanning during the same storage time, and outputting concentration data corresponding to the detected amount of detection for each base scanning; a setting part 45 for setting a scanning period Ts of a plurality of base scannings; and a determination part 44 for determining the presence or absence of foreign maters B1-B3 in matter to be inspected W on the basis of concentration data for each base scanning output by the X-ray detector 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an X-ray foreign matter detection apparatus for detecting foreign matter mixed in a test object such as meat, fish, processed food, and pharmaceuticals, and in particular, X-rays irradiated from an X-ray generator and transmitted through the test object. The present invention relates to an X-ray foreign object detection device that detects a foreign object by detecting an X-ray with a X-ray detector.

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

  Conventionally, in this type of X-ray foreign object detection apparatus, an array-shaped line sensor is used as an X-ray detector that detects X-rays that pass through an object to be inspected with X-ray irradiation. A line sensor has a plurality of detection elements arranged in a straight line in a direction perpendicular to the transport direction on a plane in the transport direction of an object to be transported, and is arranged in a line as the detection elements. And a scintillator provided on the photodiode (see, for example, Patent Document 1).

  That is, the conventional X-ray foreign object detection apparatus generates X-rays by an X-ray tube 82 provided in an X-ray generator 89 and is inspected by a line sensor 80 provided in an X-ray detector 81 as shown in FIG. X-rays that have passed through the object W are detected. The line sensor 80 includes a plurality of photodiodes 80b arranged in a line and a scintillator 80a provided on the photodiode 80b.

  When the inspection object W is inspected using the conventional X-ray foreign matter detection apparatus having the above-described configuration, the output level from each photodiode 80b is detected before the inspection without conveying the inspection object W. An appropriate correction value is set for each photodiode 80b so as to be within a range and to be a constant value, and sensitivity correction of the X-ray detector 81 is performed based on this correction value before inspection, thereby obtaining sensitivity. Based on the output level of the X-ray detector 81 after correction, foreign matters B1, B2, and B3 in the inspection object W are detected. When the difference in output level between the inspection object W and the foreign matter B1, B2, B3 is small because the thickness of the inspection object W is large, the output of the X-ray tube 82 is increased, and the inspection object W and the foreign matter are increased. Contrast (difference in output level) with B1, B2, and B3 is increased so that detection of foreign matters B1, B2, and B3 is facilitated.

  Further, as shown in FIG. 15A, the photodiodes 80b of the line sensor 80 are sequentially lined while the inspection object W moves in the X direction with respect to the photodiodes 80b arranged in the Y direction and stationary. , And density data corresponding to the amount of X-rays transmitted over the entire area of the inspection object W is output. Here, assuming that the interval in the X direction of the data for one line obtained from the line sensor 80 is d and the moving speed of the inspection object W is V, the scanning cycle T for one line in the main scanning direction is T = d. It is expressed as / V, and is output as density data representing the amount of transmitted X-rays according to the amount of light received by each photodiode 80b within the scanning period T for one line in the main scanning direction.

Further, the relationship between the thickness of the inspection object W and the amount of X-ray transmission is a logarithmic curve as shown in FIG. 15B, where the intensity of incident X-rays is I ₀ , the X-ray absorption coefficient is μ, and the inspection object When the thickness of W is x, the intensity I of the transmitted X-ray is expressed as I = I ₀ e ^−μx , and the intensity of the transmitted X-ray is proportional to the intensity of the incident X-ray.

JP 2002-168806 A

  However, in the conventional technique described in Patent Document 1, when the output of the X-ray tube 82 is increased, the inspected object W and the foreign matter B1 can be discriminated in the portion where the thickness of the inspected object W is large. However, in the portion (thin portion) where the thickness of the inspection object W is small, the X-rays transmitted through the inspection object W exceed the detection range (range) of the photodiode 80b, and the output from the photodiode 80b. Is saturated, there is a problem that the inspection object W and the foreign matters B2 and B3 cannot be distinguished.

  That is, as shown in FIG. 16A, when the X-ray output from the X-ray tube 82 is doubled, the brightness value data shown in FIG. In a small portion, the signal P1 corresponding to the foreign matter B1 mixed in can be discriminated. However, in a portion where the thickness is small and the X-ray transmission amount is large, the X-ray image is whitened due to saturation of the luminance value data output. Since the tone information is lost, the signals P2 and P3 corresponding to the foreign matters B2 and B3 mixed in the saturated portion cannot be determined, and the luminance value data is converted into digital data. Even in the density data (corresponding to the luminance value data shown in FIG. 16C), there is a problem that the signals P2 and P3 respectively corresponding to the foreign matters B2 and B3 cannot be determined.

  Therefore, the present invention has been made to solve the above-described conventional problems, and the contrast between the object to be inspected and the foreign matter can be obtained without losing the grayscale information due to saturation of the output from the X-ray detector. By increasing the height, even if foreign matter is mixed in the thick part of the object to be inspected, foreign matter is reliably detected even if foreign matter is mixed in the thin part. An object of the present invention is to provide an X-ray foreign object detection device that can perform the above-described operation.

  An X-ray foreign matter detection apparatus according to the present invention includes an X-ray generator that irradiates an inspection object conveyed on a conveyance path with X-rays, and main scanning orthogonal to the conveyance direction on a plane in the conveyance direction of the inspection object. X has a detection element array composed of a plurality of detection elements arranged linearly in the direction, performs a plurality of elementary scans for one line in the main scanning direction, and the detection elements transmit the inspection object An X-ray detector that detects a line for each elementary scan and outputs density data corresponding to the detected detection amount for each elementary scan; and a setting unit that sets a scanning cycle of the plurality of elementary scans; And determining means for determining the presence or absence of foreign matter in the inspection object based on density data for each elementary scan output by the X-ray detector.

  With this configuration, not only the signal corresponding to the foreign matter mixed in the thick part of the inspection object, but also the signal corresponding to the foreign substance mixed in the thin part of the inspection object is within the range. The determination means ensures that both the presence or absence of foreign matter mixed in the thick part of the inspection object and the presence or absence of foreign matter mixed in the thin part of the inspection object Can do.

  Therefore, by increasing the contrast between the object to be inspected and the foreign object without saturating the output from the X-ray detector and losing the density information, the foreign object is mixed in the thick part of the object to be inspected. Even if it is a case, even if it is a case where the foreign material is mixed in the part with small thickness, the X-ray foreign material detection apparatus which can detect a foreign material reliably can be provided.

  In the X-ray foreign object detection apparatus according to the present invention, the setting unit sets the scanning cycle according to the X-ray generation intensity of the X-ray generator.

  With this configuration, each element of the detection element array is saturated and density information is not lost, and the contrast between the inspection object and the foreign object is increased and the detection of the foreign object is ensured at the entire thickness of the inspection object. be able to.

  Further, the X-ray foreign object detection apparatus according to the present invention is characterized in that the setting means sets the scanning cycle in accordance with an X-ray detection amount of the X-ray detector.

  With this configuration, each element of the detection element array is saturated and density information is not lost, and the contrast between the inspection object and the foreign object is increased and the detection of the foreign object is ensured at the entire thickness of the inspection object. be able to.

  In the X-ray foreign matter detection apparatus according to the present invention, the density data output for each elementary scan is synthesized so that the parts of the inspection object coincide with each other to obtain density data for one line in the main scanning direction. It has a combining means for outputting, and the determining means determines the presence or absence of foreign matter in the inspection object based on the density data combined by the combining means.

  With this configuration, the density data output for each of the elementary scans is synthesized so that the parts of the inspection object coincide with each other and output as density data for one line in the main scanning direction. Since it is not necessary to increase the resolution and range of the A / D converter in order to receive twice the density data by dividing, the same A / D converter can be used as before, which increases costs. The foreign substance detection performance can be improved while suppressing the above.

  In the X-ray foreign object detection device according to the present invention, the X-ray detector has a plurality of the detection element arrays having different detection sensitivities, and a plurality of the detection element arrays for one line in the main scanning direction. The detection element detects X-rays that pass through the inspection object, outputs density data corresponding to the detected detection amount for each detection element array, and the determination means includes a plurality of X-ray detectors. The presence or absence of foreign matter in the inspection object is determined based on a plurality of density data output from the detection element array.

  With this configuration, the detection element arrays having different detection sensitivities cause not only a signal corresponding to the foreign matter mixed in the thick part of the inspection object but also the small part of the inspection object. It is also possible to detect the signal corresponding to the foreign object, so that there is a foreign object mixed in the thick part of the inspection object and the foreign object mixed in the thin part of the inspection object. Both can be reliably determined by the determination unit.

  Therefore, by increasing the contrast between the object to be inspected and the foreign object without saturating the output from the X-ray detector and losing the density information, the foreign object is mixed in the thick part of the object to be inspected. Even in this case, it is possible to reliably detect the foreign matter even if the foreign matter is mixed in the portion having a small thickness.

  The present invention increases the contrast between the object to be inspected and the foreign material without saturating the output from the X-ray detector and losing the density information, so that the foreign material is mixed into the thick part of the object to be inspected. Even if it is a case, even if it is a case where the foreign material is mixed in the small thickness part, the X-ray foreign material detection apparatus which can detect a foreign material reliably can be provided.

1 is a perspective view showing a schematic configuration of an X-ray foreign object detection device according to a first embodiment of the present invention. It is a figure which shows the side surface and internal structure of the X-ray foreign material detection apparatus which concern on the 1st Embodiment of this invention. It is a perspective view which shows the structure of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 1st Embodiment of this invention. (A) is a figure which shows the scan of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 1st Embodiment of this invention, (b) is the X-ray accumulation time of an X-ray detector. FIG. (A), (b) is a graph which shows the luminance value data of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 1st Embodiment of this invention, (c) respond | corresponds to density | concentration data. It is a graph which shows luminance value data. (A) is a figure which shows the scanning of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 2nd Embodiment of this invention, (b) is the X-ray accumulation time of an X-ray detector. FIG. (A), (b) is a graph which shows the luminance value data of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 2nd Embodiment of this invention, (c) respond | corresponds to density | concentration data. It is a graph which shows luminance value data. It is a perspective view which shows the structure of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 3rd Embodiment of this invention. (A) is a figure which shows the scanning of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 3rd Embodiment of this invention, (b) is the X-ray accumulation time of an X-ray detector. FIG. (A), (b) is a graph which shows the luminance value data of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 3rd Embodiment of this invention, (c) respond | corresponds to density | concentration data. It is a graph which shows luminance value data. It is a perspective view which shows the structure of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 4th Embodiment of this invention. (A) is a figure which shows the scanning of the X-ray detector of the X-ray foreign material detection apparatus which concerns on the 4th Embodiment of this invention, (b) is the X-ray accumulation time of an X-ray detector. FIG. (A), (b) is a graph which shows the luminance value data of the X-ray detector of the X-ray foreign material detection apparatus based on the 4th Embodiment of this invention, (c) respond | corresponds to density | concentration data. It is a graph which shows luminance value data. It is a perspective view which shows the structure of the X-ray detector of the conventional X-ray foreign material detection apparatus. (A) is a figure which shows the scanning of the X-ray detector of the conventional X-ray foreign material detection apparatus, (b) is a figure which shows the accumulation time of the X-ray of an X-ray detector, (c) is 4 is a graph showing the relationship between the amount of X-ray transmission and the thickness of an inspection object. (A), (b) is a graph which shows the luminance value data of the X-ray detector of the conventional X-ray foreign material detection apparatus, (c) is a graph which shows the luminance value data corresponding to density | concentration data.

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

(First embodiment)
First, the configuration will be described.

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

  The conveyance unit 2 sequentially conveys the inspection object W at a predetermined interval. This conveyance part 2 is comprised by the belt conveyor arrange | positioned horizontally 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 that penetrates the belt surface 2 a from the carry-in port 7 to the carry-out port 8 in 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 generator 9 disposed at a predetermined height above the examination space 22 in the middle of the 21 and an X-ray detector 10 disposed opposite to the X-ray generator 9 in the transport unit 2. Yes.

  An X-ray generator 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.

  Further, the intensity of the generated X-ray changes in proportion to the current (tube current) flowing between the anode and the cathode of the X-ray tube 12, and the wavelength of the generated X-ray varies with the anode and the cathode of the X-ray tube 12. , And the transmission power becomes stronger depending on the voltage (tube voltage) applied between the two and the foreign matter B1, B2, B3 (see FIG. 3) to be detected and the type and transport speed of the inspection object W. Thus, the tube current or tube voltage of the X-ray tube 12 is adjusted.

  The X-ray detector 10 has a plurality of detection elements arranged in a straight line in the Y direction orthogonal to the transport direction on the plane of the transport direction (X direction) of the object W to be transported. As shown in FIG. 5, the photodiode 30b as a plurality of detection elements arranged in a line and a line sensor 30 including a scintillator 30a provided on the photodiode 30b are configured. Further, as shown in FIG. 2, the X-ray detector 10 includes an A / D conversion unit 41. The A / D conversion unit 41 converts luminance value data from the photodiode 30b into digital data. It is output as density data. The X-ray detector 10 transmits X-rays that pass through the inspection object W by a line sensor 30 that extends linearly in a direction (Y direction) orthogonal to the plane of the conveyance direction (X direction) of the inspection object W. The density data based on the detection result is sequentially output for each photodiode 30b for all the photodiodes 30b (one line sensor 30), and sequentially with the conveyance of the inspection object W. The output is repeated, and density data can be obtained for the entire range of the inspection object W. That is, main scanning is performed in the Y direction and sub scanning is performed in the X direction by the line sensor 30 including a plurality of photodiodes 30b. The scanning of the minimum unit in the main scanning direction by the line sensor 30 is set as elementary scanning, and density data for one line in the main scanning direction is obtained by one elementary scanning or a plurality of elementary scannings. .

  In the line sensor 30 having the above configuration, when the X-ray generator 9 irradiates the inspection object W with X-rays, the X-ray transmitted through the inspection object W is received by the scintillator 30a and converted into light. . Further, the light converted by the scintillator 30a is received by a photodiode 30b disposed below the scintillator 30a. Each photodiode 30b converts the received light into an electrical signal and outputs it. The luminance value data received by the photodiode 30b and converted into an electrical signal is converted into digital data by the A / D converter 41 (see FIG. 2) and output as density data.

  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 foreign object detection device 1 includes a control unit 40 that receives density data of the photodiode 30b and determines the presence or absence of foreign substances B1, B2, and B3 in the inspection object W.

  The control unit 40 includes a storage unit 42 that stores a plurality of density data, and various filters (Roberts, Prewitt, etc.) for synthesizing and extracting foreign substances B1, B2, and B3 from one or a plurality of density data read from the storage unit 42. An image processing unit 43 that performs image processing such as a differential filter such as Sobel (or a feature extraction filter such as Labrador) and the like and performs discrimination between the inspected object W and the foreign matter B1, B2, and B3 with respect to the image-processed density data A determination unit 44 that determines whether or not foreign matter B1, B2, or B3 is mixed, and a display 5 that displays the determination result.

  In addition, the control unit 40 includes a setting unit 45. The setting unit 45 sets the X-ray output of the X-ray generator 9 and the scanning cycle Ts of the elementary scan for one line in the main scanning direction. It is supposed to be set.

  The setting unit 45 sets the scanning period Ts of elementary scanning for one line in the main scanning direction based on the density data read from the storage unit 42. Specifically, the setting unit 45 saturates the luminance value of the photodiode 30b when the concentration data read from the storage unit 42 is saturated, that is, when the concentration data exceeds the detection range (range) of the photodiode 30b. A command is given to shorten the scanning period Ts of the elementary scan so that the data is reduced.

  As shown in FIG. 4A, the setting unit 45 moves the inspection object W relative to the stationary X-ray detector 10 including a plurality of photodiodes 30b arranged in the Y direction in the sub-scanning direction. When the forward line scan (main scan) is performed, when the X-ray output (X-ray intensity) from the X-ray generator 9 is set to double the normal value, FIG. As shown in FIG. 5B, in order to reduce the accumulation time from the normal accumulation time t to t / 2 so that the luminance value data of the photodiode 30b is halved, for one line in the main scanning direction, The elementary scanning cycle Ts is changed from the normal scanning cycle Ts = T to Ts = T / 2, and the elementary scanning is performed twice. That is, if the interval for one line in the main scanning direction is d and the moving speed of the inspection object W is V, the period T for one line in the main scanning direction is expressed as T = d / V. Whereas when the X-ray output from the X-ray generator 9 is normal, the accumulation time of the photodiode 30b becomes t by one elementary scan with a scanning period Ts = T, whereas the detection output is performed. When the X-ray output from 9 is twice the normal setting, the elementary scanning is performed twice in the scanning cycle Ts = T / 2, and the photodiode 30b is shown in FIGS. 4B and 5B. Thus, after the detection output by the first elementary scan is performed at the accumulation time of t / 2, the detection output by the second elementary scan is performed at the accumulation time of t / 2. The detection output by the photodiode 30b is “reading” of the density data from the photodiode 30b for the control unit 40 to which the detection output is input.

  Here, in the matrix shown in FIG. 4A, when eight photodiodes 30b of 1 to 8 are arranged in a line, 64 matrixes are subjected to main scanning for eight columns from the A column to the H column. The state of obtaining the pixel is shown. The actual number of photodiodes 30b is much larger than that shown in FIG. 4A. For example, 1280 pixels, and the arrangement interval of the photodiodes 30b is extremely small, for example, about 0.4 mm. Yes.

  Further, the image processing unit 43 synthesizes the two detection outputs from the photodiode 30b as shown in FIG. 5C when the X-ray output from the X-ray generator 9 is set to double the normal value. Further, this combined density data is processed as a minimum pixel. In the image processing, various filter processes for extracting the foreign matters B1, B2, and B3 are performed so that the foreign matters B1, B2, and B3 are more emphasized.

  Next, the operation will be described.

  As shown in FIG. 5A, when the X-ray output from the X-ray generator 9 is twice the normal value, as shown in FIG. 4B and FIG. In response to the instruction, two elementary scans are performed for one line in the main scanning direction at an accumulation time t / 2 and a scanning cycle Ts = T / 2, and two are detected and output from the photodiode 30b. The scanning for one line in the direction is sequentially repeated for the inspection object W moving in the X direction. Also, as shown in FIG. 5C, two density data detected and output are synthesized according to the detection amount (luminance value data) detected by the photodiode 30b by the image processing unit 43. The two luminance value data from each photodiode 30b correspond to one pixel of the matrix shown in FIG. 4A, and density data obtained by synthesis (the synthesized luminance value of FIG. 5C). (Corresponding to data) means that both the thick and small portions of the object W are within the range. In the image processing unit 43, the density data obtained by the synthesis is subjected to image processing, and the foreign matters B1, B2, and B3 are further emphasized.

  For this reason, not only the signal P1 corresponding to the foreign substance B1 mixed in the thick part of the inspection object W but also the foreign substances B2 and B3 mixed in the thin part of the inspection object W, respectively. Since the corresponding signals P2 and P3 are also within the range, the presence / absence of the foreign matter B1 mixed in the thick part of the inspection object W and the foreign substance mixed in the thin part of the inspection object W The determination unit 44 can reliably determine both the presence / absence of B2 and B3.

  In the present embodiment, the X-ray detector 10 includes the A / D converter 41, but the controller 40 may include the A / D converter 41. In other words, instead of using the output from the X-ray detector 10 to the control unit 40 as density data after being converted into digital data, the control unit 40 side as luminance value data before being converted into digital data. The luminance value data may be converted into digital data by the A / D conversion unit 41 to form density data.

  As described above, the X-ray foreign object detection device 1 according to the present embodiment is linear in the main scanning direction (direction Y) orthogonal to the conveyance direction on the plane of the conveyance direction (direction X) of the inspection object W. The line sensor 30 includes a plurality of photodiodes 30b arranged. After the photodiode 30b performs detection output by the first elementary scan with an accumulation time corresponding to a predetermined scanning cycle Ts, the same accumulation time is obtained. The X-ray detector 10 that performs detection output by the second elementary scan and outputs density data corresponding to the detected detection amount for each elementary scan, and a setting unit 45 that sets the scanning cycle Ts of a plurality of elementary scans. And a determination unit 44 for determining the presence or absence of foreign matter B1, B2, B3 in the inspection object W based on density data for each elementary scan output by the X-ray detector 10. .

  For this reason, even when the X-ray output is increased to emphasize the signal P1 corresponding to the foreign matter B1 mixed in the thick part of the inspection object W, the thickness of the inspection object W is increased. Since the signals P2 and P3 corresponding to the foreign matters B2 and B3 mixed in the small portion are also within the range, the presence or absence of the foreign matter B1 mixed in the thick portion of the inspection target W and the inspection target The determination unit 44 can reliably determine both the presence / absence of the foreign matters B2 and B3 mixed in the portion where the thickness of W is small.

  Therefore, even when the X-ray output is increased, the output from the X-ray detector 10 is saturated and the contrast between the object W and the foreign matters B1, B2, and B3 is increased without losing the density information. Thus, even if the foreign object B1 is mixed in the thick part of the inspection object W, or the foreign object B2 or B3 is mixed in the thin part, the foreign object is surely B1, B2, and B3 can be detected.

  Further, the X-ray foreign object detection device 1 according to the present invention is characterized in that the setting unit 45 sets the scanning cycle Ts according to the X-ray generation intensity of the X-ray generator 9.

  With this configuration, the contrast between the inspection object W and the foreign objects B1, B2, and B3 is increased in a wide range of thicknesses of the inspection object W without saturating each photodiode 30b of the line sensor 30, and the foreign objects B1, B2, The detection of B3 can be ensured.

  Further, the X-ray foreign object detection device 1 according to the present invention is characterized in that the setting unit 45 sets the scanning cycle Ts according to the X-ray detection amount of the X-ray detector 10.

  With this configuration, the inspection object W and the inspection object W can be used in a wide range of thicknesses of the inspection object W without saturating the photodiodes 30b of the line sensor 30 corresponding to the types of inspection objects W having different thicknesses. The contrast with the foreign objects B1, B2, and B3 can be increased to ensure the detection of the foreign objects B1, B2, and B3.

  The X-ray foreign object detection apparatus 1 according to the present invention combines the density data output for each elementary scan by the X-ray detector 10 so that the parts of the inspection object W coincide with each other in the main scanning direction. An image processing unit 43 that outputs the density data for the line is included, and the determination unit 44 determines the presence or absence of foreign matters B1, B2, and B3 in the inspection object W based on the density data synthesized by the image processing unit 43. It is characterized by doing.

  With this configuration, since the density data output for each elementary scan is synthesized so that the parts of the inspection object W coincide with each other and output as density data for one line in the main scanning direction, two elementary scans are performed. Since it is not necessary to increase the resolution and range of the A / D converter 41 in order to receive twice the amount of density data, it is possible to use the same A / D converter 41 as in the past, which increases the cost. The detection performance of the foreign matters B1, B2, and B3 can be improved while being suppressed.

(Second Embodiment)
In the present embodiment, as shown in FIG. 7A, when the X-ray output of the X-ray generator 9 is set to three times the normal value, the luminance value data of the photodiode 30b in the elementary scan is 1/3. In order to change the accumulation time from the normal accumulation time t to t / 3 and 2t / 3 so as to be 2/3, the scan period Ts of the elementary scan is set to the normal scan period for one line in the main scanning direction. From Ts = T to Ts = T / 3 and Ts = 2T / 3, elementary scanning is performed twice. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  Also in the present embodiment, as shown in FIG. 6A, the X-ray detector 10 is inspected against the stationary X-ray detector 10 composed of a plurality of photodiodes 30b arranged in the X direction. The object W is relatively moved in the sub-scanning direction to sequentially scan the lines (main scan). However, the setting unit 45 has an X-ray output (X-ray intensity) from the X-ray generator 9 that is three times the normal. 6 (b) and FIG. 7 (b), the accumulation time is changed from the normal accumulation time t so that the luminance value data of the photodiode 30b becomes 1/3 and 2/3, as shown in FIGS. In order to set t / 3 and 2t / 3, the scanning period Ts of the elementary scanning is changed from the normal scanning period Ts = T to Ts = T / 3 and Ts = 2T / 3 for one line in the main scanning direction. The scanning is performed twice. That is, if the interval of one line in the main scanning direction is d and the moving speed of the inspection object W is V, the scanning cycle T for one line in the main scanning direction is expressed as T = d / V. In contrast, when the X-ray output from the X-ray generator 9 is normal, the accumulation time of the photodiode 30b is t and the detection output is performed by one elementary scan in the scanning cycle Ts = T, whereas the X-ray generation is performed. When the X-ray output from the detector 9 is set to three times the normal setting, the elementary scanning is performed twice in the scanning periods Ts = T / 3 and Ts = 2T / 3, and the photodiode 30b is shown in FIG. As shown in FIG. 7B, after the detection output by the first elementary scan is performed at the accumulation time of t / 3, the detection output by the second elementary scan is performed at the accumulation time of 2t / 3. ing.

  Further, the two luminance value data from the photodiode 30b are converted into digital data by the A / D conversion unit 41 to become two density data (corresponding to the luminance value data in FIG. 7C). One of these two density data is one in which the whole shade of the inspection object W is within the range, and the other is one in which the gradation of the thick part of the inspection object W is emphasized.

  Further, the image processing unit 43 performs image processing on each of the two density data converted into the digital data using the density data as a minimum pixel. In the image processing, various filter processes for extracting the foreign matters B1, B2, and B3 are performed so that the foreign matters B1, B2, and B3 are more emphasized.

  The determination unit 44 determines whether or not the foreign matter B1, B2, B3 of the inspection object W is mixed in both of the two density data subjected to image processing by the image processing unit 43. For this reason, the determination unit 44 includes the foreign matter B2 and B3 mixed in the portion where the thickness of the inspection object W is small from the concentration data corresponding to the accumulation time of the photodiode 30b of the two concentration data. And the foreign matter B1 mixed in the thick part of the inspection object W can be determined from the density data corresponding to the accumulation time of the photodiode 30b of 2t / 3.

  Next, the operation will be described.

  As shown in FIG. 7A, when the X-ray output from the X-ray generator 9 is three times normal, as shown in FIG. 6B and FIG. In response to the instruction, the first detection output is performed with the accumulation time t / 3 and the scanning cycle Ts = T / 3 for one line in the main scanning direction, and the accumulation time 2t / 3 is scanned from the first detection output. A second detection output is performed at a cycle Ts = 2T / 3, and a similar scan for one line in the main scanning direction is sequentially repeated with respect to the inspection object W moving in the X direction. Further, as shown in FIG. 7C, the two detection outputs from the photodiode 30b are converted into digital data by the A / D conversion unit 41, and according to the detection amount (luminance value data) detected by the photodiode 30b. The two density data detected and output are obtained. One of these density data (corresponding to the luminance value data shown in FIG. 7C) is one in which the entire shade of the inspection object W is within the range, and the other is the thickness of the inspection object W being large. The shade of the part will be emphasized. In the image processing unit 43, each of these two density data is subjected to image processing such as various filters for extracting the foreign matters B1, B2, and B3 using the obtained density data as the minimum pixel, and the foreign matter B1. , B2 and B3 are more emphasized.

  Here, the density data obtained when the scanning cycle Ts = 2T / 3 is saturated for the foreign matters B2 and B3 in the portion where the thickness of the inspection object W is small, but the inspection object W is not saturated. Contrast with the inspected object W becomes high for the foreign matter B1 in the thick part. On the other hand, in the density data obtained when the scanning cycle Ts = T / 3, the foreign objects B2 and B3 in the portion where the thickness of the inspection object W is small have high contrast with the inspection object W, and the inspection object. Contrast with the inspection object W is in a low state for the foreign matter B1 in the portion where the thickness of W is large.

  For this reason, the X-ray output is strengthened, the density data in which the signal P1 corresponding to the foreign matter B1 mixed in the thick part of the inspection object W is emphasized, and the thickness of the inspection object W is small. Since the signals P2 and P3 respectively corresponding to the foreign matters B2 and B3 mixed in the portion can be obtained together with the density data that falls within the range, the foreign matter B1 mixed in the thick portion of the inspection object W is obtained. The determination unit 44 can reliably determine both the presence / absence and the presence / absence of the foreign matters B2 and B3 mixed in the portion where the thickness of the inspection object W is small.

  As described above, the X-ray foreign object detection device 1 according to the present embodiment is linear in the main scanning direction (direction Y) orthogonal to the conveyance direction on the plane of the conveyance direction (direction X) of the inspection object W. The line sensor 30 includes a plurality of photodiodes 30b arranged, and the photodiode 30b performs detection output by the first elementary scan with an accumulation time corresponding to a predetermined scanning cycle Ts. An X-ray detector 10 that performs detection output by the second elementary scan with different accumulation times and outputs density data corresponding to the detected detection amount for each elementary scan and a scanning cycle Ts of a plurality of elementary scans are set. A setting unit 45 and a determination unit 44 that determines the presence or absence of foreign matters B1, B2, and B3 in the inspection object W based on density data for each elementary scan output from the X-ray detector 10. Features.

  For this reason, the X-ray output is strengthened, the density data in which the signal P1 corresponding to the foreign matter B1 mixed in the thick part of the inspection object W is emphasized, and the thickness of the inspection object W is small. Since the signals P2 and P3 respectively corresponding to the foreign matters B2 and B3 mixed in the portion can also be obtained together with the density data falling within the range, the foreign matter B1 mixed in the thick portion of the object W to be inspected The determination unit 44 can reliably determine both the foreign matters B2 and B3 mixed in the portion where the thickness of the inspection object W is small.

  Therefore, even when the X-ray output is increased, the output from the X-ray detector 10 is saturated and the contrast between the object W and the foreign matters B1, B2, and B3 is increased without losing the density information. Thus, even if the foreign object B1 is mixed in the thick part of the inspection object W, or the foreign object B2 or B3 is mixed in the thin part, the foreign object is surely B1, B2, and B3 can be detected.

(Third embodiment)
In the present embodiment, as shown in FIG. 8, X-ray generation is performed on an inspected object W having a shape that continuously changes from a thick portion to a small portion, as shown in FIG. When the X-ray output of the detector 9 is set to three times the normal value, the accumulation time is changed from the normal accumulation time t to t / so that the luminance value data of the photodiode 30b in the elementary scan becomes 1/3 and 2/3. In order to set 3 and 2t / 3, for one line in the main scanning direction, the scanning period Ts of the elementary scanning is changed from the normal scanning period Ts = T to Ts = T / 3 and Ts = 2T / 3. It is supposed to be performed twice. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  Also in the present embodiment, as shown in FIG. 8, the X-ray detector 10 is provided on a plurality of photodiodes 30b as detection elements arranged in a line and on the photodiode 30b. A line sensor 30 including a scintillator 30a, and as shown in FIG. 9A, an object W to be inspected with respect to a stationary X-ray detector 10 including a plurality of photodiodes 30b arranged in the X direction. Are moved relative to each other in the sub-scanning direction, and the main scanning is sequentially performed. However, detection output is performed on the inspected object W having a shape that continuously changes from a thick part to a small part.

  As shown in FIG. 9A, the setting unit 45 moves the inspection object W relative to the stationary X-ray detector 10 including a plurality of photodiodes 30b arranged in the X direction in the sub-scanning direction. When the main scan is performed, as shown in FIG. 10A, when the X-ray output (X-ray intensity) of the X-ray generator 9 is set to three times the normal value, FIG. ), As shown in FIG. 10B, for the photodiode 30b, for one line in the main scanning direction, the detection output by the first elementary scanning with the accumulation time t / 3 and the scanning cycle Ts = T / 3. After performing the above, the detection output by the second elementary scan is performed at the accumulation time 2t / 3 and the scanning cycle Ts = 2T / 3.

  Further, the two luminance value data from the photodiode 30b are converted into digital data by the A / D conversion unit 41 to become two density data (corresponding to the luminance value data shown in FIG. 10C). One of these two density data is one in which the whole shade of the inspection object W is within the range, and the other is one in which the gradation of the thick part of the inspection object W is emphasized.

  Further, the image processing unit 43 performs image processing on each of the two density data converted into the digital data using the density data as a minimum pixel. In the image processing, various filter processes for extracting the foreign matters B1, B2, and B3 are performed so that the foreign matters B1, B2, and B3 are more emphasized.

  The determination unit 44 determines whether or not the foreign matter B1, B2, B3 of the inspection object W is mixed in both of the two density data subjected to image processing by the image processing unit 43. For this reason, the determination unit 44 includes the foreign matter B2 and B3 mixed in the portion where the thickness of the inspection object W is small from the concentration data corresponding to the accumulation time of the photodiode 30b of the two concentration data. And the foreign matters B1 and B3 mixed in the thick part of the inspection object W can be determined from the density data corresponding to the accumulation time of the photodiode 30b of 2t / 3.

  Next, the operation will be described.

  As shown in FIG. 10A, when the X-ray output from the X-ray generator 9 is three times normal, as shown in FIG. 9B and FIG. In response to the instruction, the first detection output is performed with the accumulation time t / 3 and the scanning cycle Ts = T / 3 for one line in the main scanning direction, and the accumulation time 2t / 3 is scanned from the first detection output. A second detection output is performed at a cycle Ts = 2T / 3, and a similar scan for one line in the main scanning direction is sequentially repeated with respect to the inspection object W moving in the X direction. In addition, the two detection outputs from the photodiode 30b are converted into digital data by the A / D converter 41, and the two density data detected and output according to the detection amount (luminance value data) detected by the photodiode 30b are converted. obtain. One of these two density data (corresponding to the luminance value data shown in FIG. 10C) is one in which the entire shade of the inspection object W is within the range, and the other is the thickness of the inspection object W. The shade of the large part is emphasized. In the image processing unit 43, each of these two density data is subjected to image processing such as various filters for extracting the foreign matters B1, B2, and B3 using the obtained density data as the minimum pixel, and the foreign matter B1. , B2 and B3 are more emphasized.

  Here, the density data obtained when the scanning cycle Ts = 2T / 3 is saturated for the foreign matter B2 in the portion where the thickness of the inspection object W is small, but the thickness of the inspection object W which is not saturated. Contrast with the inspected object W is high for the foreign substance B1 in the large part, and the contrast next to the foreign substance B1 is partially saturated for the foreign substance B3 in the middle part of the thickness of the inspected object W. Becomes high. On the other hand, the density data obtained when the scanning cycle Ts = T / 3 has a high contrast with the inspection object W for the foreign matter B2 in the portion where the thickness of the inspection object W is small. The foreign matter B3 in the middle portion of the thickness has the second highest contrast after the foreign matter B2, and the foreign matter B1 in the thick portion of the inspection object W has a low contrast with the inspection object W. Go.

  For this reason, the foreign material B1 mixed in the thick part of the inspection object W, the foreign material B2 mixed in the thin part of the inspection object W, and the thickness of the inspection object W Since it is possible to detect both the signals P1, P2 and P3 respectively corresponding to the foreign matter B3 mixed in the portion of the degree, the presence or absence of the foreign matter B1 mixed in the thick portion of the inspection object W From the presence / absence of the foreign matter B2 mixed in the portion where the thickness of the inspection object W is small and the presence / absence of the foreign matter B3 mixed in the middle portion of the thickness of the inspection object W Can be reliably determined from the thick part to the small part of the object W to be inspected.

  As described above, the X-ray foreign object detection device 1 according to the present embodiment is linear in the main scanning direction (direction Y) orthogonal to the conveyance direction on the plane of the conveyance direction (direction X) of the inspection object W. The line sensor 30 includes a plurality of arranged photodiodes 30b, and the photodiode 30b is subjected to the first elementary scan with an accumulation time corresponding to a predetermined scanning cycle Ts for one line in the main scanning direction. An X-ray detector 10 that performs detection output by the second elementary scan with an accumulation time different from the first time after performing the detection output, and outputs density data corresponding to the detected detection amount for each elementary scan, The presence or absence of foreign matter B1, B2, B3 in the inspected object W is determined based on the setting unit 45 that sets the scanning period Ts of a plurality of elementary scans and the density data for each elementary scan output by the X-ray detector 10. And a determination unit 44 It is characterized in.

  For this reason, the X-ray output is strengthened, the density data in which the signal P1 corresponding to the foreign matter B1 mixed in the thick part of the inspection object W is emphasized, and the thickness of the inspection object W is small. While the signal P2 corresponding to the foreign matter B2 mixed in the portion falls within the range, and partially saturated corresponding to the foreign matter B3 mixed in the middle portion of the thickness of the inspection object W Since both the density data of the signal P3 with increased contrast can be obtained, the foreign matter B1 mixed in the thick part of the inspection object W and the thin part of the inspection object W are mixed. The determination unit 44 can reliably determine the foreign matter B2 that is present and the foreign matter B3 that is mixed in the middle portion of the thickness of the inspection object W.

  Therefore, even when the X-ray output is increased, the output from the X-ray detector 10 is saturated and the contrast between the object W and the foreign matters B1, B2, and B3 is increased without losing the density information. Therefore, even if the foreign object B1 is mixed in the thick part of the inspection object W or the foreign object B2 is mixed in the thin part, Even if the foreign matter B3 is mixed in the middle part of the foreign matter, the foreign matter B1, B2, B3 can be reliably detected.

(Fourth embodiment)
In this embodiment, as shown in FIG. 11, the presence or absence of foreign matter B1, B2, B3 in the inspection object W is inspected using two line sensors 30, 31 having different detection sensitivities. Yes. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  In the present embodiment, as shown in FIG. 11, the X-ray detector 10 includes a line sensor 31 in addition to the line sensor 30, which has a X-ray detection sensitivity different from that of the line sensor 30. Similar to the line sensor 30, the line sensor 31 includes a photodiode 31b as a plurality of detection elements arranged in a line and a scintillator 31a provided on the photodiode 31b. The line sensor 30 and the line sensor 31 are arranged close to each other as shown in FIG.

  As shown in FIG. 12A, the setting unit 45 is configured so that the object W to be inspected is relative to the stationary X-ray detector 10 composed of a plurality of photodiodes 30b and 31b arranged in the Y direction. When moving and sequentially scanning the line (main scan), as shown in FIG. 13A, the X-ray output (X-ray intensity) from the X-ray generator 9 is set to three times the normal value. In this case, elementary scanning is performed on both the photodiodes 30b and 31b. That is, when the interval of one line in the main scanning direction is d and the moving speed of the inspection object W is V, the scanning cycle T of one line portion in the main scanning direction is expressed as T = d / V. As shown in FIGS. 12B and 13B, both the photodiodes 30b and 31b are caused to perform detection output by elementary scanning in the scanning period Ts = T of elementary scanning and the accumulation time t. ing.

  Further, the two luminance value data output from the photodiode 30b and the photodiode 31b are converted into digital data by the A / D conversion unit 41 and correspond to the two density data (luminance value data shown in FIG. 13C). ) One of these two density data is one in which the whole shade of the inspection object W is within the range, and the other is one in which the gradation of the thick part of the inspection object W is emphasized.

  Further, the image processing unit 43 performs image processing on each of the two density data converted into the digital data using the density data as a minimum pixel. In the image processing, various filter processes for extracting the foreign matters B1, B2, and B3 are performed so that the foreign matters B1, B2, and B3 are more emphasized.

  The determination unit 44 determines whether or not the foreign matters B1, B2, and B3 of the inspection object W are mixed in both of these two density data. For this reason, the determination unit 44 detects the foreign matter mixed in the thick part of the inspection object W from the density data having the higher detection sensitivity of the photodiode 30b and the photodiode 31b. The presence / absence of B1 is determined, and the presence / absence of foreign matters B2 and B3 mixed in the portion having a small thickness of the inspection object W is determined from the density data with the smaller detection sensitivity of the photodiode 30b and the photodiode 31b. Yes.

  Next, the operation will be described.

  As shown in FIG. 13 (a), when the X-ray output from the X-ray generator 9 is three times normal, it is shown in FIG. 12 (b) and FIG. 13 (b) according to an instruction from the setting unit 45. As described above, both the photodiode 30b and the photodiode 31b output luminance value data in the scanning period Ts = T of the elementary scan and the accumulation time t, and the scanning for one line in the main scanning direction is moved in the X direction. It repeats sequentially with respect to the inspection object W. Also, the two luminance value data from the photodiode 30b and the photodiode 31b are converted into digital data by the A / D converter 41, and detected and output according to the detection amount (luminance value data) detected by the photodiodes 30b and 31b. The obtained two density data (corresponding to the luminance value data shown in FIG. 13C) is obtained. One of these two density data is one in which the whole shade of the inspection object W is within the range, and the other is one in which the gradation of the thick part of the inspection object W is emphasized. In the image processing unit 43, image processing is performed on each of these two density data so that the foreign matters B1, B2, and B3 are more emphasized.

  Here, since the two density data have different detection sensitivities even if the accumulation times in the photodiodes 30b and 31b are the same, the density data obtained from the photodiodes 30b and 31b having the higher detection sensitivity are the inspected objects. The foreign matters B2 and B3 in the portion where the thickness of W is small are saturated, but the contrast between the foreign matter B1 in the portion where the thickness of the inspection object W is large and the inspection object W is high. On the other hand, in the density data obtained from the photodiode 30b, 31b having the smaller detection sensitivity, the foreign matter B2, B3 in the portion where the thickness of the inspection object W is small has high contrast with the inspection object W. Contrast with the inspected object W is low for the foreign matter B1 in the thick part of the inspected object W.

  For this reason, the X-ray output is strengthened, the density data in which the signal P1 corresponding to the foreign matter B1 mixed in the thick part of the inspection object W is emphasized, and the thickness of the inspection object W is small. Since the signals P2 and P3 respectively corresponding to the foreign matters B2 and B3 mixed in the portion can be obtained together with the density data that falls within the range, the foreign matter B1 mixed in the thick portion of the inspection object W is obtained. The determination unit 44 can reliably determine both the presence / absence and the presence / absence of the foreign matters B2 and B3 mixed in the portion where the thickness of the inspection object W is small.

  In the present embodiment, detection is performed with the scanning period Ts = T of elementary scanning. However, as in the second embodiment or the third embodiment, scanning for one line in the main scanning direction is performed. Thus, more elementary scans may be performed with a scan cycle of Ts = T / 3 and Ts = 2T / 3, and the presence or absence of foreign matter B1, B2, B3 may be determined based on the detection output associated therewith.

  As described above, the X-ray foreign object detection device 1 according to the present embodiment is linear in the main scanning direction (direction Y) orthogonal to the conveyance direction on the plane of the conveyance direction (direction X) of the inspection object W. The line sensor 30 includes a plurality of photodiodes 30b and the line sensor 31 includes a plurality of photodiodes 31b. The detection sensitivity of the photodiodes 30b and 31b is different from each other. In addition, X-rays that pass through the inspection object W are detected at every scanning cycle Ts = T of a predetermined elementary scanning, and the detection amount at every scanning cycle Ts with respect to scanning for one line in the main scanning direction. The X-ray detector 10 for outputting the corresponding density data, the setting unit 45 for setting the scanning period Ts, and the photodiode 3 for each scanning period Ts by the X-ray detector 10. b and a determination unit 44 for determining the presence or absence of foreign matter B1, B2, B3 mixed in the inspection object W based on density data output from each of the photodiodes 31b. .

  For this reason, the signal P1 corresponding to the foreign matter B1 mixed in the thick part of the object W to be intensified by the line sensors 30 and 31 having different X-ray detection sensitivities by strengthening the X-ray output. The obtained density data and the density data in which the signals P2 and P3 respectively corresponding to the foreign matters B2 and B3 mixed in the small thickness portion of the inspection object W are also within the range can be obtained. The determination unit 44 reliably determines both the presence / absence of the foreign matter B1 mixed in the thick portion of W and the presence / absence of the foreign matters B2 and B3 mixed in the thin portion of the inspection object W. be able to.

  Therefore, even when the X-ray output is increased, the output from the X-ray detector 10 is saturated and the contrast between the object W and the foreign matters B1, B2, and B3 is increased without losing the density information. Thus, even if the foreign object B1 is mixed in the thick part of the inspection object W, or the foreign object B2 or B3 is mixed in the thin part, the foreign object is surely B1, B2, and B3 can be detected.

  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 claims for patent, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims for patent.

  As described above, the X-ray foreign object detection device according to the present invention can be used to inspect the inspection object without losing the grayscale information because the output from the X-ray detector is saturated even when the X-ray output is increased. By increasing the contrast with the foreign material, even if the foreign object is mixed in the thick part of the object to be inspected, even if the foreign object is mixed in the thin part It is useful as an X-ray foreign object detection device that detects X-rays emitted from an X-ray generator and transmitted through an object to be detected by an X-ray detector. It is.

DESCRIPTION OF SYMBOLS 1 X-ray foreign material detection apparatus 2 Conveyance part 2a Belt surface 3 Detection part 4 Case 5 Indicator 6 Drive motor 7 Carry-in port 8 Carry-out port 9 X-ray generator 10 X-ray detector 11 Box 12 X-ray tube 16 Shield curtain 21 Transport path 21a Ceiling part 22 Inspection space 30, 31 Line sensor (detection element array)
30a, 31a Scintillator 30b, 31b Photodiode (detection element)
40 control unit 41 A / D conversion unit 42 storage unit 43 image processing unit (combining means)
44 determination unit (determination means)
45 Setting part (setting means)
W Inspection object B1, B2, B3 Foreign object P1, P2, P3 signal

Claims (5)

An X-ray generator (9) for irradiating the inspection object (W) transported on the transport path (21) with X-rays;
A detection element array (30) comprising a plurality of detection elements (30b) arranged linearly in a main scanning direction (direction Y) orthogonal to the conveyance direction on a plane in the conveyance direction (direction X) of the inspection object. A plurality of elementary scans for one line in the main scanning direction, and the detection element detects X-rays transmitted through the inspection object for each elementary scan, and according to the detected amount of detection. An X-ray detector (10) for outputting the density data for each elementary scan;
Setting means (45) for setting a scanning period of the plurality of elementary scans;
Determination means (44) for determining the presence or absence of foreign matter (B1, B2, B3) in the inspection object based on density data for each elementary scan output by the X-ray detector. X-ray foreign matter detection device.   The X-ray foreign substance inspection apparatus according to claim 1, wherein the setting means (45) sets the scanning cycle according to the X-ray generation intensity of the X-ray generator (9).   The X-ray foreign substance inspection apparatus according to claim 1, wherein the setting means (45) sets the scanning cycle in accordance with an X-ray detection amount of the X-ray detector (10). The density data output for each of the elementary scans by the X-ray detector (10) is synthesized so that the parts of the inspection object (W) coincide with each other and output as density data for one line in the main scanning direction. A synthesizing means (43)
The said determination means (44) determines the presence or absence of the foreign material (B1, B2, B3) in the said to-be-inspected object based on the density | concentration data synthesize | combined by the said synthetic | combination means. The X-ray foreign matter detection device according to any one of 2. The X-ray detector (10) has a plurality of detection element arrays (30, 31) having different detection sensitivities, and a plurality of detection elements in the detection element array are inspected for one line in the main scanning direction. In addition to detecting X-rays that pass through the object, concentration data corresponding to the detected detection amount is output for each detection element array,
The determination means (44) determines the presence or absence of foreign matter (B1, B2, B3) in the inspection object based on a plurality of density data output from a plurality of detection element arrays of the X-ray detector. The X-ray foreign material detection apparatus according to claim 1, wherein:

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