JP2015090341A - Radiation inspection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation inspection system small in size and high in abnormality detection capability.SOLUTION: A radiation abnormality inspection system includes: transport means 30 transporting an inspection target article 2 in a predetermined direction; a first radiation source 21 irradiating the inspection target article 2 with a radiation 24; a second radiation source 22 irradiating the inspection target article 2 with a radiation different in quality from the radiation 24 emitted from the first radiation source 21; a first radiation line sensor 41; a second radiation line sensor 42; and image synthesis means 45. The radiation abnormality inspection system further includes a radiation shield 23 for preventing the second radiation sensor 42 from detecting the radiation 24 emitted from the first radiation source 21 and preventing the first radiation line sensor 41 from detecting the radiation emitted from the second radiation source 22.

Description

  The present invention relates to a radiation inspection system, and more particularly, to a radiation inspection system (radiation foreign matter inspection system) for inspecting foreign matter mixed in an inspection object.

  As one method for inspecting foreign matters mixed in an object to be inspected, such as food and medicine, without destroying the object to be inspected, there is a method using radiation.

  A radiation inspection system that inspects foreign matter mixed in an object to be inspected using radiation usually has a radiation generating unit having a radiation generating tube, a conveyance path for conveying the object to be inspected, and an inspection generated from the radiation generating unit. A radiation line sensor for detecting radiation that has passed through the object. Of the radiation inspection systems, those that inspect foreign matters mixed in the object to be inspected are sometimes called radiation foreign matter inspection systems.

  By the way, the radiation foreign substance inspection system is required to improve the foreign substance detection capability, and a subtraction method is known as a technique that satisfies this requirement. As a radiation foreign substance inspection system employing the subtraction method, for example, there is a system disclosed in Patent Document 1. Specifically, an image is emphasized by appropriately combining a plurality of images obtained by irradiating radiations having different energies from each radiation generation unit, each having a plurality of radiation generation units and radiation line sensors. As a result, information on foreign matters can be obtained.

JP 2013-88144 A

  However, in the method proposed in Patent Document 1, a so-called crosstalk problem occurs in which a predetermined X-ray line sensor detects X-rays other than X-rays to be detected by the X-ray line sensor. As a method for preventing this crosstalk, there is a method in which the respective X-ray line sensors are arranged at regular intervals. However, if the interval between the X-ray line sensors is wide, a relative positional shift of the inspection object moving on the conveyance path may occur between them, and a suitable subtraction image may not be obtained, and the foreign object detection capability may be significantly impaired. This is particularly noticeable in bag-like confectionery, retort foods that are fluids, and the like. Further, when the distance between the plurality of X-ray sources and the plurality of X-ray line sensors is simply reduced, the X-rays emitted from the first X-ray source are other than the predetermined X-ray line sensor (first X-ray line sensor). Or the X-ray is not sufficiently irradiated to the first X-ray line sensor. As a result, a suitable subtraction image cannot be obtained, and there is a problem that the foreign matter detection capability is low.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a radiation foreign matter inspection system that is small and has a high foreign matter detection capability.

The radiation inspection system of the present invention includes a transport means for transporting an object to be inspected in a predetermined direction
A first radiation source for irradiating the inspection object with radiation;
A second radiation source that irradiates the inspection object with radiation having a radiation quality different from the radiation emitted from the first radiation source;
A first radiation line sensor that generates image data in accordance with a dose of radiation irradiated from the first radiation source and transmitted through the inspection object;
A second radiation line sensor that generates image data in accordance with a dose of radiation irradiated from the second radiation source and transmitted through the inspection object;
In the radiation inspection system, comprising: image combining means for combining image data generated by the first radiation line sensor and the second radiation line sensor,
Radiation emitted from the first radiation source is prevented from being detected by the second radiation line sensor, and radiation emitted from the second radiation source is prevented from being detected by the first radiation line sensor It is characterized by including a radiation shield for the purpose.

  In the radiation inspection system of the present invention, a radiation shield is appropriately provided so as not to irradiate a line sensor other than the corresponding radiation line sensor with radiation irradiated from each radiation source. As a result, crosstalk, which has been a problem in the past, can be prevented even though the arrangement intervals of the plurality of radiation line sensors are narrow. For this reason, radiation images having different radiation qualities can be obtained while reducing the positional deviation of the subject. Therefore, according to the present invention, it is possible to provide a radiation foreign object inspection system that is small and has a high foreign object detection capability.

It is the schematic which shows the example of a radiation inspection apparatus provided with the radiation inspection system of this invention. It is the schematic which shows 1st embodiment in the radiographic inspection system of this invention. It is the schematic which shows 2nd embodiment in the radiographic inspection system of this invention. It is the schematic which shows 3rd embodiment in the radiographic inspection system of this invention. It is the schematic which shows 4th embodiment in the radiographic inspection system of this invention. (A) is schematic which shows 5th embodiment in the radiographic inspection system of this invention, (b-1) thru | or (b-3) are the radiation sources which comprise the radiographic inspection system of (a). It is the schematic which shows the example of the installation aspect of the radiation target with which it is equipped. It is the schematic which shows 6th embodiment in the radiographic inspection system of this invention.

  The present invention relates to a radiation inspection system including a transport unit, a first radiation source, a second radiation source, a first radiation line sensor, a second radiation line sensor, and an image composition unit. In the radiation inspection system of the present invention, the transport means refers to a configuration for transporting the inspection object in a predetermined direction. In the radiation inspection system of the present invention, the first radiation source and the second radiation source are radiation sources that irradiate the inspection object with radiation. However, the second radiation source is a radiation source that irradiates radiation having a quality different from that irradiated from the first radiation source. In the radiation inspection system of the present invention, the first radiation line sensor is a line sensor that generates image data according to the dose of radiation irradiated from the first radiation source and transmitted through the inspection object. In the radiation inspection system of the present invention, the second radiation line sensor is a line sensor that generates image data according to the dose of radiation irradiated from the second radiation source and transmitted through the inspection object. In the radiation inspection system of the present invention, the image synthesizing means is configured to synthesize image data generated by the first radiation line sensor and the second radiation line sensor.

  The radiation inspection system of the present invention includes a radiation shield. The radiation shield prevents radiation emitted from the first radiation source from being detected by the second radiation line sensor and detects radiation emitted from the second radiation source to the first radiation line sensor. It is provided to prevent this from happening.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. However, the present invention is not limited to the embodiments described below. Moreover, there is no specific description about the dimension, material, shape, relative arrangement of each component, selection method, design, etc. described in the following description, and the gist of the present invention is not exceeded. It is possible to change the setting as long as possible.

[Radiation inspection equipment]
FIG. 1 is a schematic view showing an example of a radiation inspection apparatus including the radiation inspection system of the present invention. The radiation inspection apparatus 1 in FIG. 1 includes a housing 10 that includes a carry-in port 11 and a carry-out port 12, and members that are provided inside the housing 10. Here, the members provided inside the housing 10 are specifically the members indicated by the following (a) to (d).
(A) A radiation generating unit 20 comprising a first radiation source 21 and a second radiation source 21
(B) Radiation shield 23
(C) Conveying means 30 comprising a belt conveyor 31 and a motor (not shown)
(D) Radiation detection means 40 comprising a first radiation line sensor 41 and a second radiation line sensor 42

  In the radiation inspection apparatus 1 of FIG. 1, the two radiation sources (21, 22) constituting the radiation generation unit 20 each include an electron gun (not shown) and a radiation target (21a, 22a), and a housing The member itself is a vacuum container. Further, in the radiation inspection apparatus 1 of FIG. 1, each radiation source (21, 22) includes one electron gun and one radiation target (21 a, 22 a). Furthermore, in the radiation inspection apparatus 1 of FIG. 1, each radiation source (21, 22) is preferably a transmissive radiation source. Incidentally, the radiation quality and intensity of radiation radiated from the radiation targets (21a, 22a) respectively provided in the radiation sources (21, 22) are the tube voltage and tube current applied to the radiation sources (21, 22), respectively. , Depending on the composition of the radiation target or a combination thereof. Examples of radiation emitted from each radiation target (21a, 22a) include X-rays, but the present invention is not limited to this.

  In the radiation inspection apparatus 1 of FIG. 1, the inspection object 2 carried in from the carry-in port 11 is moved to the carry-out port 12 by the carrying means 30 along the X direction in FIG. 1 and at a preset carrying speed. Be transported.

  In the radiation inspection apparatus 1 of FIG. 1, two radiation line sensors (41, 42) are arranged in a direction perpendicular to the X direction that is the conveyance direction of the inspection object 2, that is, in the Y direction in FIG. 1. Arranged along. Here, the first radiation line sensor 41 is a sensor that detects only the radiation generated from the first radiation target 21 a and transmitted through the inspection object 2. On the other hand, the second radiation line sensor 42 detects only the radiation generated from the second radiation target 22a and transmitted through the inspection object 2. By the way, when the characteristics of the radiation targets (21a, 22a) provided in the two radiation sources (21, 22) constituting the radiation inspection apparatus 1 of FIG. 1 are different, the radiation quality is different from that of each radiation target (21a, 22a). Each of these radiations can be generated. As described above, when radiation having different radiation quality is emitted from each radiation target (21a, 22a), information obtained by each radiation line sensor (41, 42) by detecting these radiations, for example, an image. Information will be different. Moreover, the information regarding the image which each radiation line sensor (41, 42) each acquires is output as an image by an image output part (not shown). Then, by synthesizing a plurality of images output using an image synthesizing means (not shown), a subtraction image in which foreign matter is emphasized can be obtained. Note that the image output unit and the image composition unit may be provided inside the housing 10 or outside the housing 10.

In the radiation inspection apparatus 1 of FIG. 1, a radiation shield 23 is provided at a predetermined position in the housing 10. The radiation shield 23 plays the roles shown in (i) and (ii) below.
(I) The radiation generated from the first radiation target 21a is not detected by the second radiation line sensor 42. (ii) The radiation generated from the second radiation target 22a is the first radiation line. Prevent detection by the sensor 41

  In the present invention, the material of the radiation shield 23 is not particularly limited, but is preferably a metal material such as copper, iron, tungsten, or lead that has excellent radiation shielding ability. More preferred is a heavy metal material such as tungsten or lead. The radiation shield 23 may be an alloy formed by combining a plurality of metal materials.

  As described above, since the radiation inspection apparatus 1 in FIG. 1 is provided with the radiation shield 23 at a predetermined position in the housing 10, the radiation generated from the predetermined radiation target is a predetermined radiation line sensor. Can be selectively detected. For this reason, it is possible to make the space | interval of two radiation line sensors (41, 42) as narrow as possible. For this reason, it is possible to reduce the positional deviation of the inspection object 2 and to obtain a suitable subtraction image. Therefore, the radiation foreign object inspection apparatus of the present invention is an inspection apparatus having a high foreign object detection capability.

[Radiation inspection system]
Next, a radiation inspection system included in the radiation foreign object inspection apparatus of the present invention will be described with reference to the drawings as appropriate. The radiation inspection system here mainly refers to a radiation foreign matter inspection system, for example, an inspection system employed in the radiation inspection apparatus 1 of FIG.

(Embodiment 1)
FIG. 2 is a schematic view showing a first embodiment in the radiation inspection system of the present invention. The radiation inspection system 3 in FIG. 2 has two types of radiation sources, that is, a first radiation source 21 and a second radiation source 22.

  In the radiation inspection system 3 of FIG. 2, the first radiation source 21 includes a first radiation target 21a and a first electron gun 21b. Further, the first radiation target 21 a and the first electron gun 21 b constituting the first radiation source 21 are included in a vacuum container (first vacuum container 21 c) serving as a housing of the first radiation source 21. Yes.

  By applying a high voltage, for example, a voltage of 70 kV, to the first electron gun 21b, an electron beam is irradiated from the first electron gun 21b toward the first radiation target 21a. The intensity of the electron beam emitted from the first electron gun 21b can be adjusted by adjusting the voltage applied to the first electron gun 21b.

  The first radiation target 21a is made of a metal material mainly containing tungsten, for example. In response to the electron beam emitted from the first electron gun 21b, the first radiation 24 is emitted from the first radiation target 21a. The first radiation 24 is radiation that is irradiated toward the inspection object 2 and the first radiation line sensor 41.

  In the radiation inspection system 3 of FIG. 2, the second radiation source 22 includes a second radiation target 22 a and a second electron gun 22 b. The second radiation target 22a and the second electron gun 22b constituting the second radiation source 22 are enclosed in a vacuum container (second vacuum container 22c) which is a housing of the second radiation source 22. Yes.

  For example, when a voltage of 30 kV is applied to the second electron gun 22b, an electron beam is emitted from the second electron gun 22b toward the second radiation target 22a. The intensity of the electron beam emitted from the second electron gun 22b can be adjusted by adjusting the voltage applied to the second electron gun 22b. The voltage applied to the second electron gun 22b does not necessarily need to be lower than the voltage applied to the first electron gun 21b. That is, the voltage applied to the second electron gun 22b may be set equal to or higher than the voltage applied to the first electron gun 21b.

  The second radiation target 22a is made of, for example, a metal material mainly made of molybdenum. In response to the electron beam emitted from the second electron gun 22b, the second radiation 25 is emitted from the second radiation target 22a. The constituent material of the second radiation target 22a may be the same as or different from the constituent material of the first radiation target 21a. The second radiation 25 is radiation that is irradiated toward the inspection object 2 and the second radiation line sensor 42.

  A part of the first radiation 24 irradiated from the first radiation target 21 a is detected by the first radiation line sensor 41. Here, in the radiation inspection system 3 of FIG. 2, the first radiation target 24 a that connects the first radiation target 21 a and the first radiation line sensor 41 is conveyed by the belt conveyor 31 that constitutes the conveying means 30. Inspected object 2 passes. For this reason, the first radiation line sensor 41 transmits the first radiation 24 itself irradiated from the first radiation target 21 a toward the first radiation line sensor 41 and the first radiation that has passed through the inspection object 2. Radiation (not shown) is detected.

  On the other hand, a part of the second radiation 25 irradiated from the second radiation target 22 a is detected by the second radiation line sensor 42. Here, in the radiation inspection system 3 of FIG. 2, the second radiation 25 is connected to the second radiation target 22 a and the second radiation line sensor 42, and is conveyed by the belt conveyor 31 constituting the conveying means 30. Inspected object 2 passes. For this reason, the second radiation line sensor 42 transmits the second radiation 25 itself irradiated from the second radiation target 22 a toward the second radiation line sensor 42 and the second radiation that has passed through the inspection object 2. Radiation (not shown) is detected.

  By the way, in the radiation inspection system 3 of FIG. 2, the radiation (24, 25) irradiated from the radiation targets (21a, 22a) to the corresponding radiation line sensors (41, 42) has a cone shape. Is. When cone-shaped radiation is irradiated in this way, a portion where the two radiations overlap may occur depending on the positions and intervals of the two radiation sources (21, 22). Here, in order to prevent the radiation line sensor (41, 42) from being provided in the overlapping portion of the two radiations, a predetermined distance between the radiation target (21a, 22a) and the radiation line sensor (41, 42) is obtained. A radiation shield 23 is provided in the space. By providing this radiation shield 23, the problem of crosstalk, which has been a problem in the past, is solved, and each radiation line sensor (41, 42) can be operated even when the installation interval of each radiation line sensor (41, 42) is narrow. The radiation to be detected can be selected. Specifically, the first radiation 24 can be selectively detected by the first radiation line sensor 41, and the second radiation 25 can be selectively detected by the second radiation line sensor 42.

  As a constituent material of the radiation shield 23, for example, a metal material that does not transmit radiation, such as lead and tungsten, is mainly cited.

  In the radiation inspection system 3 of FIG. 2, electrical signals are generated in the first radiation line sensor 41 and the second radiation line sensor 42 according to the detected radiation dose. Here, the electrical signals generated from the radiation line sensors (41, 42) are converted into a form of radiation image data by a predetermined image output unit (43 or 44). Specifically, the electrical signal output from the first radiation line sensor 41 is converted into first radiation image data by the first image output unit 43. On the other hand, the electrical signal output from the second radiation line sensor 42 is converted into second radiation image data by the second image output unit 44.

  In each image output unit (43, 44), the two types of radiation image data converted from the electrical signal are combined by the image combining means 45 and output as a subtraction image in which foreign matter is emphasized.

(Embodiment 2)
FIG. 3 is a schematic view showing a second embodiment in the radiation inspection system of the present invention. The radiation inspection system 4 in FIG. 3 has the same configuration as the radiation inspection system 3 in FIG. 2 except that the installation position of the radiation shield is different.

  In the radiation inspection system 4 of FIG. 3, the radiation shields (23 a, 23 b) are provided in the vicinity of the radiation targets (21 a, 22 a), respectively, and have slits for allowing radiation to pass therethrough. . In the radiation inspection system 4 of FIG. 3, the irradiation area | region of the radiation (24a, 25a) radiated | emitted from each radiation target (21a, 22a) is controlled by the slit which a radiation shield (23a, 23b) has. For this reason, each radiation (24a, 25a) is irradiated almost selectively onto a region on the radiation line sensor. Specifically, the first radiation 24a is applied to an area on the first radiation line sensor (area indicated by reference numeral 41a), and the second radiation 25a is applied to an area on the second radiation line sensor ( The region indicated by reference numeral 42a is irradiated.

  As a result, radiation leakage from a carry-in / out port (not shown) can be prevented, so that the apparatus can be further miniaturized.

(Embodiment 3)
FIG. 4 is a schematic view showing a third embodiment in the radiation inspection system of the present invention. The radiation inspection system 5 of FIG. 4 includes a radiation source 26 contained in a vacuum container (vacuum container 26a) in which two types of radiation targets (21a, 22a) and two types of electron guns (21b, 22b) are shared. It is used. As described above, the radiation inspection system 5 of FIG. 4 has the same configuration as that of the radiation inspection system 3 of FIG. 2 except that the radiation sources used are different.

  As in the radiation inspection system 5 of FIG. 4, in the present invention, a member constituting the first radiation source 21 for emitting the first radiation 24 and a second for emitting the second radiation 25 are used. The members constituting the radiation source 22 may be included in a common vacuum vessel 26a.

  The radiation inspection system 5 of FIG. 4 can be used in place of the radiation inspection system 3 of FIG. 2, for example, when the voltages applied to the two types of electron guns (21b, 22b) are the same (for example, 70 kV). . However, in the radiation inspection system 5 of FIG. 4, the voltage applied to each electron gun (21b, 22b) is not limited in the same manner as in the radiation inspection system 3 of FIG. The intensity of the electron beam emitted from each of (21b, 22b) can be appropriately adjusted.

(Embodiment 4)
FIG. 5 is a schematic view showing a fourth embodiment in the radiation inspection system of the present invention. The radiation inspection system 6 in FIG. 5 has the same configuration as the radiation inspection system 5 in FIG. 4 except that the installation position of the radiation shield is different.

  In the radiation inspection system 6 of FIG. 5, the radiation shields (23 a, 23 b) are provided in the vicinity of the radiation targets (21 a, 22 a), respectively, and have slits for allowing radiation to pass therethrough. . In the radiation inspection system 6 of FIG. 5, the irradiation area of the radiation (24a, 25a) emitted from each radiation target (21a, 22a) is controlled by a slit included in each radiation shield (23a, 23b). For this reason, each radiation (24a, 25a) is irradiated almost selectively onto a region on the radiation line sensor. Specifically, the first radiation 24a is applied to an area on the first radiation line sensor (area indicated by reference numeral 41a), and the second radiation 25a is applied to an area on the second radiation line sensor ( The region indicated by reference numeral 42a is irradiated.

  As a result, radiation leakage from a carry-in / out port (not shown) can be prevented, so that the apparatus can be further miniaturized.

(Embodiment 5)
FIG. 6A is a schematic view showing a fifth embodiment of the radiation inspection system of the present invention, and FIGS. 6B-1 to 6B-3 are views of the radiation inspection system of FIG. 7 is a schematic diagram illustrating an example of an installation mode of a radiation target provided in a radiation source that constitutes 7. Hereinafter, the description will focus on the differences from the radiation inspection system of FIG.

  The radiation inspection system 7 in FIG. 6A includes a vacuum container 27d as a radiation source casing, two types of radiation targets (27a and 27b) contained in the vacuum container 27d, and an electron gun as a radiation source. 27c is used. That is, the radiation inspection system 7 in FIG. 6A is similar in that the electron gun 27c that is the irradiation source of the electron beam irradiated to the two types of radiation targets (27a, 27b) is common. The configuration is the same as that of the radiation inspection system 5 in FIG.

  Therefore, in the radiation inspection system 7 of FIG. 6A, the two types of radiation targets (27a, 27b) are irradiated with a common electron beam emitted from the electron gun 27c. Here, if the constituent materials of the radiation targets (27a, 27b) are different, radiations having different properties are emitted from the radiation targets (27a, 27b). For example, the first radiation target 27a is a radiation target made of a metal material containing tungsten, and the second radiation target 27b is a radiation target made of a metal material containing molybdenum. Thereby, the radiation (24, 25) emitted from each radiation target (27a, 27b) has different properties.

  In the present embodiment, the two types of radiation targets (27a, 27b) are arranged on the end surface portion of the vacuum container 27d serving as a casing, as in the other embodiments. As for the arrangement position, shape, size, etc. of the two types of radiation targets (27a, 27b), both of the two types of radiation targets (27a, 27b) are included in the radiation region of the electron beam emitted from the electron gun 27c. Is set as appropriate.

  As the arrangement position of each radiation target (27a, 27b), it is preferable to arrange each radiation target (27a, 27b) so as to contact each other as shown in FIG. 6 (b-1). However, as long as it does not deviate from the electron beam irradiation area, a certain interval is provided between the radiation targets (27a, 27b) as shown in FIGS. 6 (b-2) and (b-3). Also good.

  Examples of the shape of each radiation target (27a, 27b) include a rectangular shape, a circular shape, and an elliptical shape, but are not particularly limited in the present invention.

  The size of each radiation target (27a, 27b) may be the same as shown in FIGS. 6 (b-1) and (b-2) or as shown in FIG. 6 (b-3). May be different.

In this embodiment, the specific arrangement | positioning aspect of two types of radiation targets (27a, 27b) is shown below. However, the present invention is not limited to these embodiments.
(5-1) Each radiation target (27a, 27b) has the same substantially square shape (for example, 1.5 mm on a side), and both radiation targets (27a, 27b) are in contact (between each radiation target). No gap) embodiment (FIG. 6 (b-1))
(5-2) A mode in which each radiation target (27a, 27b) has the same substantially circular shape (for example, a diameter of 1.0 mm), and there is a fixed interval between each radiation target (FIG. 6B-2). ))
(5-3) Each radiation target (27a, 27b) has a substantially circular shape, there is a fixed interval between each radiation target, and the size of each radiation target (27a, 27b) is different (for example, the diameter) 1.0 mm circular shape, 1.5 mm diameter circular shape) embodiment (FIG. 6 (b-3))

(Embodiment 6)
FIG. 7 is a schematic view showing a sixth embodiment in the radiation inspection system of the present invention. The radiation inspection system 8 in FIG. 7 has the same configuration as the radiation inspection system 7 in FIG. 6 except that the installation position of the radiation shield is different.

  In the radiation inspection system 8 of FIG. 7, the radiation shield 23d is provided in the vicinity of each radiation target (27a, 27b), and has a slit for allowing predetermined radiation to pass therethrough. In the radiation inspection system 8 of FIG. 7, the radiation area of the radiation (24a, 25a) emitted from each radiation target (27a, 27b) is controlled by a slit of the radiation shield 23d. For this reason, each radiation (24a, 25a) is irradiated almost selectively onto a region on the radiation line sensor. Specifically, the first radiation 24a is applied to an area on the first radiation line sensor (area indicated by reference numeral 41a), and the second radiation 25a is applied to an area on the second radiation line sensor ( The region indicated by reference numeral 42a is irradiated.

  As a result, radiation leakage from a carry-in / out port (not shown) can be prevented, so that the apparatus can be further miniaturized.

[Example 1]
The radiation inspection system 3 of FIG. 2 was produced by the method shown below.

(1) Radiation source In this example, a transmissive radiation tube was used as the radiation source (21, 22). Here, when a transmissive radiation tube is used as the radiation source (21, 22), since the radiation extraction angle is wider than that of a general reflection radiation tube, the distance between the focal point and the sensor may be shortened. It becomes possible.

  In this embodiment, the Z-direction interval between the first radiation target 21a and the first radiation line sensor 41 and the Z-direction interval between the second radiation target 22a and the second radiation line sensor 42 are both set to 350 mm. did.

  Further, when two radiation sources (21, 22) were installed, the X-direction interval between the first radiation target 21a and the second radiation target 22a was set to 50 mm.

(2) Line sensor The 1st radiation line sensor 41 and the 2nd radiation line sensor 42 were each installed so that the space | interval of the X direction of each line sensor might be set to 50 mm.

(3) Radiation shield The radiation shield 23 was placed by attaching two tungsten sheets (manufactured by Nippon Tungsten Co., Ltd.) to a screen provided with a passage that is perpendicular to the X direction and through which the inspection object passes. . The tungsten sheet used had a thickness of 3 mm, a vertical length of 50 mm, and a horizontal length comparable to the length of each radiation line sensor (41, 42). Further, when the tungsten sheet is attached, the screen is provided so that the radiation shield 23 is provided in a manner that is in the middle of the first radiation line sensor 41 and the second radiation line sensor 42 and crosses the X direction. The position of was adjusted. Furthermore, when this tungsten sheet was affixed, the lower side in the Z direction was positioned 150 mm from the upper side of each radiation line sensor (41, 42).

  According to this configuration, the first radiation line sensor 41 can selectively detect the first radiation 24 emitted from the first radiation source 21. Also, the second radiation 25 emitted from the second radiation source 22 can be selectively detected by the second radiation line sensor 42. Therefore, it was possible to provide a small-sized radiation foreign matter inspection system with high foreign matter detection capability.

[Example 2]
The radiation inspection system 5 of FIG. 4 was produced by the method shown below.

(1) Radiation source In this example, a transmissive radiation tube was used as the radiation source. The radiation tube used in this example is a radiation tube 26 enclosed in a vacuum vessel 26a in which two types of electron guns (21b, 22b) and two types of radiation targets (21a, 22a) are shared. It was. Moreover, the space | interval (X direction space | interval) of each radiation target (21a, 22a) was 30 mm.

  In this embodiment, the Z-direction interval between the first radiation target 21a and the first radiation line sensor 41 and the Z-direction interval between the second radiation target 22a and the second radiation line sensor 42 are both set to 350 mm. did.

(2) Line sensor The 1st radiation line sensor 41 and the 2nd radiation line sensor 42 were each installed so that the space | interval of the X direction of each line sensor might be 30 mm.

(3) Radiation shield The radiation shield 23 was placed by attaching two tungsten sheets (manufactured by Nippon Tungsten Co., Ltd.) to a screen provided with a passage that is perpendicular to the X direction and through which the inspection object passes. . The tungsten sheet used had a thickness of 3 mm, a vertical length of 50 mm, and a horizontal length comparable to the length of each radiation line sensor (41, 42). Further, when the tungsten sheet is attached, the screen is provided so that the radiation shield 23 is provided in a manner that is in the middle of the first radiation line sensor 41 and the second radiation line sensor 42 and crosses the X direction. The position of was adjusted. Furthermore, when this tungsten sheet was affixed, the lower side in the Z direction was positioned 150 mm from the upper side of each radiation line sensor (41, 42).

  According to this configuration, the first radiation line sensor 41 can selectively detect the first radiation 24 emitted from the first radiation source 21. Also, the second radiation 25 emitted from the second radiation source 22 can be selectively detected by the second radiation line sensor 42. Further, it has been found that even if the interval between the radiation line sensors (41, 42) is narrower than that of the first embodiment, predetermined radiation can be selectively detected by the corresponding radiation line sensor. Therefore, it was possible to provide a radiation foreign object inspection system that is smaller than Example 1 and has a higher foreign object detection capability.

[Example 3]
The radiation inspection system 7 of FIG. 6 was produced by the method shown below.

(1) Radiation source In this example, a transmissive radiation tube was used as the radiation source. The radiation tube used in this example was a radiation tube contained in a vacuum container 27 in which the electron gun 28 and two types of radiation targets (27a, 27b) are shared. In the radiation tube used in this example, as shown in FIG. 6 (b-1), the two rectangular radiation targets (27a, 27b) were in contact with each other.

  In this embodiment, the Z-direction interval between the first radiation target 27a and the first radiation line sensor 41 and the Z-direction interval between the second radiation target 28a and the second radiation line sensor 42 are both set to 350 mm. did.

(2) Line sensor The 1st radiation line sensor 41 and the 2nd radiation line sensor 42 were each installed so that the space | interval of the X direction of each line sensor might be 6 mm.

(3) Radiation shielding body The radiation shielding body 23 was arranged by sticking one tungsten sheet (manufactured by Nippon Tungsten Co., Ltd.) to a partition provided with a passage opening that is perpendicular to the X direction and through which an inspection object passes. . The dimensions of the tungsten sheet used were 1.5 mm in thickness, 50 mm in length, and the same length as the length of each radiation line sensor (41, 42). Further, when the tungsten sheet is attached, the screen is provided so that the radiation shield 23 is provided in a manner that is in the middle of the first radiation line sensor 41 and the second radiation line sensor 42 and crosses the X direction. The position of was adjusted. Furthermore, when this tungsten sheet was affixed, the lower side in the Z direction was positioned to be 270 mm from the upper side of each radiation line sensor (41, 42).

  According to this configuration, the first radiation line sensor 41 can selectively detect the first radiation 24 emitted from the first radiation source 21. Also, the second radiation 25 emitted from the second radiation source 22 can be selectively detected by the second radiation line sensor 42. Further, it has been found that even if the interval between the radiation line sensors (41, 42) is narrower than those in the first and second embodiments, predetermined radiation can be selectively detected by the corresponding radiation line sensor. Therefore, it was possible to provide a radiation foreign object inspection system that is smaller than Examples 1 and 2 and has a higher foreign object detection capability.

  1: radiation inspection apparatus, 2: inspection object, 10: housing, 20: radiation generation unit, 21: first radiation source, 21a (27a): first radiation target, 21b (22b, 27c): electron Gun, 21c (22c, 26a, 27d): Vacuum container, 22: Second radiation source, 22a (27b): Second radiation target, 23 (23a, 23b, 23d): Radiation shield, 24 (24a) : First radiation, 25 (25a): Second radiation, 26 (27): Radiation source, 30: Conveyance means, 40: Radiation detection means, 41 :: First radiation line sensor, 42: Second radiation Radiation line sensor, 43: first image output unit, 44: second image output unit, 45: image composition means

Claims (6)

Conveying means for conveying the object to be inspected in a predetermined direction;
A first radiation source for irradiating the inspection object with radiation;
A second radiation source that irradiates the inspection object with radiation having a radiation quality different from the radiation emitted from the first radiation source;
A first radiation line sensor that generates image data in accordance with a dose of radiation irradiated from the first radiation source and transmitted through the inspection object;
A second radiation line sensor that generates image data in accordance with a dose of radiation irradiated from the second radiation source and transmitted through the inspection object;
In the radiation foreign object inspection system, comprising: an image synthesis unit that synthesizes image data generated by the first radiation line sensor and the second radiation line sensor,
Radiation emitted from the first radiation source is prevented from being detected by the second radiation line sensor, and radiation emitted from the second radiation source is prevented from being detected by the first radiation line sensor A radiation inspection system comprising a radiation shield for performing the operation. The first radiation source includes a first electron gun contained in a first vacuum container and irradiating electrons, and a first radiation target irradiating radiation according to the electrons irradiated by the first electron gun. And having
The second radiation source includes a second electron gun that is contained in a second vacuum container and irradiates electrons, and a second radiation target that irradiates radiation according to the electrons irradiated by the second electron gun. The radiation inspection system according to claim 1, further comprising: The first radiation source has a first electron gun that irradiates electrons, and a first radiation target that irradiates radiation according to electrons irradiated by the first electron gun,
The second radiation source has a second electron gun that irradiates electrons, and a second radiation target that irradiates radiation according to electrons irradiated by the second electron gun,
The radiation inspection system according to claim 1, wherein the first electron gun and the second electron gun are contained in a common vacuum container. The first radiation source has a first radiation target;
The second radiation source has a second radiation target;
The radiation inspection system according to claim 1, wherein the first radiation target and the second radiation target emit radiation according to electrons emitted from a common electron gun. The radiation shield controls an irradiation area of the radiation irradiated from the first radiation source to an area on the first radiation line sensor;
The said radiation shield controls the irradiation area | region of the radiation irradiated from said 2nd radiation source to the area | region on said 2nd radiation line sensor, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. The foreign matter inspection system according to item.   The radiation foreign object inspection system according to any one of claims 1 to 5, wherein the first radiation source and the second radiation source are transmissive radiation sources.

Images