Foreign body inspection equipment

Abstract

This foreign matter inspection device 1 comprises an X-ray irradiation unit 6 for irradiating X-rays L1 onto an object S under inspection conveyed by a conveyance unit 5, an X-ray detection unit 7 for detecting X-rays L1 that have passed through the object S under inspection and outputting X-ray image data based on the result of the detection, an infrared emission unit 8 for emitting infrared rays L2 onto the object S under inspection conveyed by the conveyance unit 5, and an infrared ray detection unit 9 for detecting infrared rays L2 from the object S under inspection and outputting infrared image data based on the result of the detection. The infrared emission unit 8 and the infrared ray detection unit 9 are enclosed by a protection part 21 comprising a member that blocks X-rays L1 and transmits infrared rays L2.

Description

[Technical field]

[0001] The present disclosure relates to a foreign matter inspection device. [Background technology]

[0002] Currently, for example in the field of food manufacturing, non-destructive foreign body inspection is performed using metal detectors and X-ray inspection devices. For example, a package inspection device described in Patent Document 1 is configured with a moving mechanism for moving a package in which contents are stored in an outer packaging, an irradiation unit for irradiating the package with X-rays, a detection unit for detecting the X-rays that have passed through the package, an illumination unit for illuminating the package, and an optical detection unit for acquiring an optical image of the package. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 049765 Summary of the Invention [Problem to be solved by the invention]

[0004] The X-ray inspection device as described above is good at detecting hard-substance foreign bodies such as metal, stone, and glass. On the other hand, the X-ray inspection device is not good at detecting soft-substance foreign bodies such as plastic, insects, hair, and mold. An example of a device that helps detect soft-substance foreign bodies is an infrared inspection device that uses infrared rays. However, the manufacturers of X-ray inspection devices and infrared inspection devices are completely separate, and the technologies of both have progressed separately. For this reason, in order to inspect a wide variety of foreign bodies including hard and soft materials, it is necessary to deploy an X-ray inspection device and an infrared inspection device separately, and the appearance of a compact foreign body inspection device has been desired.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a foreign body inspection device that is compact and capable of inspecting a wide variety of foreign bodies, including hard and soft substances. [Means for solving the problem]

[0006] A foreign body inspection device according to one aspect of the present disclosure is a foreign body inspection device that inspects the presence or absence of foreign bodies in an object to be inspected, and includes a conveying unit that conveys the object to be inspected in a predetermined conveying direction, an X-ray irradiation unit that irradiates the object to be inspected conveyed by the conveying unit with X-rays, an X-ray detection unit that detects X-rays that have passed through the object to be inspected and outputs X-ray image data based on the detection results, an infrared irradiation unit that irradiates the object to be inspected conveyed by the conveying unit with infrared rays, an infrared detection unit that detects infrared rays from the object to be inspected and outputs infrared image data based on the detection results, a protective unit having a material that blocks X-rays and transmits infrared rays and is arranged to cover the infrared irradiation unit and the infrared detection unit, and an image generation unit that generates an X-ray image of the object to be inspected based on the X-ray image data, and generates an infrared image of the object to be inspected based on the infrared image data.

[0007] In this foreign body inspection device, foreign body inspection by X-ray irradiation and foreign body inspection by infrared irradiation are performed sequentially on the inspection object transported by the inspection object. Therefore, compared with the case where an X-ray inspection device and an infrared inspection device are separately installed, inspection of a wide variety of foreign bodies including hard and soft substances can be performed compactly. In addition, in using both X-ray and infrared, a protective part having a member that blocks X-ray and transmits infrared rays is provided so as to cover the infrared irradiation part and the infrared detection part. Therefore, it is possible to prevent malfunctions of the infrared irradiation part and the infrared detection part due to exposure to X-rays, and to perform foreign body inspection with high accuracy.

[0008] The X-ray irradiation position and the infrared irradiation position on the inspection object may be different positions in the transport direction, and the detection timing of the X-ray in the X-ray detection unit and the detection timing of the infrared rays in the infrared detection unit may be synchronized. In this way, by differentiating the X-ray irradiation position and the infrared irradiation position and synchronizing the detection timing of the X-ray and the infrared rays, it is possible to match the inspection position by the X-ray and the inspection position by the infrared rays even if the inspection object has a certain thickness.

[0009] The X-ray detection unit may output a synchronization signal to the infrared detection unit in response to the detection timing of the X-rays, thereby enabling the detection timing of the X-rays in the X-ray detection unit and the detection timing of the infrared rays in the infrared detection unit to be suitably synchronized.

[0010] The infrared detection unit may output a synchronization signal to the X-ray detection unit in response to the detection timing of the infrared rays, thereby enabling the detection timing of the X-ray detection unit and the detection timing of the infrared rays in the infrared detection unit to be suitably synchronized.

[0011] The foreign body inspection device may further include a synchronization unit that synchronizes the detection timing of X-rays in the X-ray detection unit with the detection timing of infrared rays in the infrared detection unit, thereby enabling the detection timing of X-rays in the X-ray detection unit and the detection timing of infrared rays in the infrared detection unit to be suitably synchronized.

[0012] The synchronization unit may be configured with a pulse generator, in which case the synchronization signal can be generated with high accuracy.

[0013] The synchronization unit may be configured with an encoder that detects the amount of movement of the inspection object in the transport unit. In this case, the encoder can generate a synchronization signal with high accuracy.

[0014] The infrared detection unit may detect at least one of infrared rays reflected from the inspection object and infrared rays transmitted through the inspection object, thereby making it possible to preferably inspect one side or the other side of the inspection object.

[0015] The infrared detection unit may have a slit disposed in correspondence with the optical path of infrared rays from the inspection object, thereby reducing the incidence of X-rays from outside the optical path of infrared rays onto the infrared detection unit.

[0016] The image generating unit may generate a superimposed image by superimposing the X-ray image and the infrared image, whereby the inspection results using the X-rays and the infrared rays can be confirmed at once in the superimposed image.

[0017] The image generating unit may correct one of the X-ray image and the infrared image so that the number of pixels of the X-ray image and the number of pixels of the infrared image match, and then superimpose the X-ray image and the infrared image, thereby improving the accuracy of detecting foreign objects using the superimposed image.

[0018] The inspection device may further include an ultraviolet ray irradiation unit that irradiates the inspection object transported by the transport unit with ultraviolet rays, an ultraviolet ray detection unit that detects ultraviolet rays from the inspection object and outputs ultraviolet ray image data based on the detection result, and a protective unit that has a material that blocks X-rays and transmits ultraviolet rays and is provided to cover the ultraviolet ray irradiation unit and the ultraviolet ray detection unit. In this case, for example, it becomes possible to detect the autofluorescence of the inspection object, and it becomes possible to inspect a wider variety of foreign bodies. Effect of the Invention

[0019] According to the present disclosure, inspection of a wide variety of foreign objects, including hard and soft materials, can be performed in a compact manner. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic diagram showing a configuration of a foreign matter inspection device according to a first embodiment of the present disclosure. [Diagram 2] 2 is a block diagram showing functional components of the foreign matter inspection apparatus shown in FIG. 1. [Diagram 3] FIG. 11 is a plan view illustrating an example of a correction chart. [Figure 4] FIG. 11 is a schematic diagram showing a configuration of a foreign matter inspection device according to a second embodiment of the present disclosure. [Diagram 5] FIG. 13 is a schematic diagram showing the configuration of a foreign matter inspection device according to a third embodiment of the present disclosure. [Figure 6] FIG. 6 is a block diagram showing functional components of the foreign matter inspection device shown in FIG. 5. [Figure 7] FIG. 13 is a diagram showing the correspondence relationship between inspection methods and inspectable foreign objects. [Figure 8] 13(a) and 13(b) are schematic diagrams showing modified examples of the protective part. [Figure 9] 13(a) and 13(b) are schematic diagrams showing another example of an infrared line sensor. [Figure 10] 13(a) and 13(b) are schematic diagrams showing yet another example of an infrared line sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, a preferred embodiment of a foreign matter inspection device according to one aspect of the present disclosure will be described in detail with reference to the drawings.

[0022] FIG. 1 is a schematic diagram showing the configuration of a foreign matter inspection device according to a first embodiment of the present disclosure. FIG. 2 is a block diagram showing functional components of the foreign matter inspection device shown in FIG. 1. This foreign matter inspection device 1 is a device that continuously inspects the presence or absence of foreign matter in an inspection object S using both X-rays L1 and infrared rays L2. An example of the inspection object S is a package that packages food. Foreign matter that is inspected by the foreign matter inspection device 1 includes both hard and soft substances. Hard substances are substances with a relatively high density, such as metals, stones, and glass. Soft substances are substances with a relatively low density, such as plastics, insects, hair, and mold.

[0023] 1, the foreign matter inspection device 1 includes a shielding box 2. The shielding box 2 is formed of a material such as lead capable of blocking X-rays L1 used for inspection so that the X-rays L1 do not leak to the outside of the shielding box 2. An inlet 3 for introducing the inspection object S into the shielding box 2 and an outlet 4 for discharging the inspection object S from the shielding box 2 are provided on opposing side portions 2a, 2a of the shielding box 2, respectively.

[0024] As shown in FIG. 1 and FIG. 2, the foreign body inspection device 1 includes a conveying section 5, an X-ray irradiation section 6, an X-ray detection section 7, an infrared irradiation section 8, an infrared detection section 9, a synchronization section 10, an image generation section 11, a judgment section 12, and a display section 13. The conveying section 5 is a section that conveys the inspection object S in a predetermined conveying direction. In the example of FIG. 1, the conveying section 5 is composed of a plurality of belt conveyors 14 horizontally arranged corresponding to the positions of the inlet 3 and the outlet 4 of the shielding box 2. The plurality of belt conveyors 14 convey the plurality of inspection objects S from the right side of the paper of FIG. 1 to the left side of the paper at a constant speed and at constant intervals. The inspection object S introduced into the shielding box 2 from the inlet 3 is inspected by the X-ray L1 and the infrared ray L2 in the shielding box 2, and then discharged from the outlet 4 to the outside of the shielding box 2.

[0025] The X-ray irradiation unit 6 is a part that irradiates the inspection object S transported by the transport unit 5 with X-rays L1. In this embodiment, the X-ray irradiation unit 6 is configured by, for example, an X-ray tube 15, and is arranged above the transport unit 5 on the discharge port 4 side in the shielding box 2. The X-rays L1 generated at the X-ray focus (point light source) of the X-ray tube 15 are emitted downward from the X-ray tube 15. The X-rays L1 are incident on the X-ray detection unit 7 after passing through the inspection object S on the transport unit 5. In this embodiment, the gap between the belt conveyors 14, 14 is located at the irradiation position of the X-rays L1 on the inspection object S. As a result, the X-rays L1 that have passed through the inspection object S are directed toward the X-ray detection unit 7 without hitting the belt conveyor 14.

[0026] The X-ray detection unit 7 detects the X-ray L1 transmitted through the inspection object S and outputs X-ray image data based on the detection result. The X-ray detection unit 7 is configured, for example, by an X-ray line sensor 18, and is disposed below the conveyor 5 at a position directly below the X-ray irradiation unit 6. The X-ray detection unit 7 detects the X-ray L1 transmitted through the inspection object S and generates X-ray image data based on the detection result. The X-ray detection unit 7 outputs the generated X-ray image data to the image generator 11 (see FIG. 2). The X-ray line sensor constituting the X-ray detection unit 7 may be a single line sensor or a multi-line sensor. The X-ray detection unit 7 may be configured by a TDI (Time Delay Integration) sensor. The X-ray detection unit 7 may be a detector compatible with multi-energy, such as a dual energy X-ray line sensor. The detection method may be an indirect conversion method using a scintillator, or a direct conversion method without using a scintillator.

[0027] 1, the X-rays L1 pass through the gap between the belt conveyors 14, 14, but the belt conveyor 14 may be made of a material that is transparent to X-rays, so that no gap is generated in the belt conveyor 14. Also, a slit made of a member that blocks X-rays may be provided between the X-ray tube 15 and the inspection target S to reduce irradiation of X-rays L to areas other than the inspection target S. In this case, the slit may be made of lead, tungsten, iron, stainless steel, copper, or the like that can block X-rays L1.

[0028] The infrared irradiation unit 8 is a part that irradiates the inspection object S transported by the transport unit 5 with infrared rays L2. The infrared irradiation unit 8 is composed of, for example, a pair of infrared light sources 16, 16. As the infrared light source 16, for example, a light emitting diode, a halogen lamp, a laser light source, or the like is used. The infrared detection unit 9 is a part that detects the infrared rays L2 from the inspection object S and outputs infrared image data based on the detection result. The infrared detection unit 9 is composed of, for example, an infrared line sensor 17 such as an InGaAs line sensor. Here, the infrared detection unit 9 detects a part of the infrared rays L2 reflected by the inspection object S and generates infrared image data based on the detection result. Then, the infrared detection unit 9 outputs the generated infrared image data to the image generation unit 11 (see FIG. 2). The infrared line sensor 17 constituting the infrared detection unit 9 may be a single line sensor like the X-ray detection unit 7, or may be a multi-line sensor having multiple line sensors. The multi-line sensor may have different sensitivity wavelengths for each line sensor. The infrared line sensor 17 may be composed of a TDI sensor. As the infrared detection unit 9, other than the infrared line sensor 17, for example, an imaging spectroscopic camera in which an imaging spectroscopic optical system capable of dispersing from visible wavelengths to infrared wavelengths and a two-dimensional detection element are combined can be used.

[0029] In this embodiment, the irradiation position of the X-ray L1 and the irradiation position of the infrared ray L2 on the inspection object S are different positions in the transport direction. In the example of FIG. 1, the irradiation position of the infrared ray L2 on the inspection object S is on the front stage side in the transport direction, and the irradiation position of the X-ray L1 on the inspection object S is on the rear stage side in the transport direction. The front-rear relationship of the irradiation positions of the X-ray L1 and the infrared ray L2 on the inspection object S with respect to the transport direction of the inspection object S may be reversed from the example of FIG. 1. That is, the irradiation position of the infrared ray L2 on the inspection object S may be on the rear stage side in the transport direction, and the irradiation position of the X-ray L1 on the inspection object S may be on the front stage side in the transport direction.

[0030] 1 and 2, in this embodiment, the infrared irradiator 8 and the infrared detector 9 are configured with an infrared irradiator 8A and an infrared detector 9A for inspecting one side of the inspection object S, and an infrared irradiator 8B and an infrared detector 9B for inspecting the other side of the inspection object S. The infrared irradiator 8A and the infrared detector 9A are disposed below the transport unit 5 on the side of the inlet 3 in the shielding box 2. A portion of the infrared ray L2 emitted upward from the infrared irradiator 8A is reflected by the one side of the inspection object S on the transport unit 5, and then enters the infrared detector 9A.

[0031] In this embodiment, a gap between the belt conveyors 14, 14 is located at the irradiation position of the infrared ray L2 on one side of the inspection target S, so that the infrared ray L2 heading toward the inspection target S and the infrared ray L2 reflected by the one side of the inspection target S head toward the infrared detection unit 9A without hitting the belt conveyor 14. The infrared ray irradiation unit 8B and the infrared detection unit 9B are disposed above the conveyor 5 on the rear side of the infrared ray irradiation unit 8A and the infrared detection unit 9B. A part of the infrared ray L2 emitted downward from the infrared ray irradiation unit 8B is reflected by the other side of the inspection target S on the conveyor 5 and then enters the infrared detection unit 9B. In the example of FIG. 1, the infrared ray L2 passes through the gap between the belt conveyors 14, 14, but the belt conveyor 14 may be made of a material that is transparent to infrared rays, so that no gap is generated in the belt conveyor 14.

[0032] As shown in FIG. 1, the infrared ray irradiating unit 8 and the infrared ray detecting unit 9 are disposed in a protective unit 21. The protective unit 21 is provided so as to cover the infrared ray irradiating unit 8 and the infrared ray detecting unit 9. The main body 21a of the protective unit 21 is formed of a material capable of shielding the X-ray L1, such as lead, tungsten, iron, stainless steel, or copper, similar to the shielding box 2. A window 21b formed of a material that shields the X-ray L1 and transmits the infrared ray L2 is provided in a front portion of the protective unit 21 (a portion located on the optical path of the infrared ray L2 from the infrared ray irradiating unit 8 and the infrared ray L2 from the inspection target S). An example of a material for forming the window 21b is lead glass. Alternatively, a lead-free radiation shielding glass can be used as a material for forming the window 21b. The lead-free radiation shielding glass may contain a heavy element such as Sr, Ba, Ti, B, W, Si, Gd, or Zr. The material for forming the window 21b is not limited to glass, and may be a resin such as acrylic.

[0033] As shown in FIG. 1, the infrared detection unit 9 has a slit 22 arranged corresponding to the optical path of the infrared ray L2 from the inspection target S. The slit 22 is formed of a material capable of blocking the X-ray L1, such as lead, tungsten, iron, stainless steel, or copper, similar to the shielding box 2. The slit 22 may have a constant thickness or may be cylindrical. By increasing the thickness of the slit 22, the incidence of scattered X-rays and infrared stray light can be prevented, and noise caused by scattered X-rays and infrared stray light can be reduced. This improves the signal-to-noise ratio and improves the inspection accuracy. The material for forming the slit 22 may be lead glass or lead-free radiation shielding glass, similar to the window portion 21b. In this embodiment, the slit 22 is arranged inside the protective portion 21 near the detection surface of the infrared detection unit 9. The tip of the slit 22 may be located outside the protective portion 21 (window portion 21b). Also, the rear end of the slit 22 may be located outside the protective portion 21 (window portion 21b). That is, the entire slit 22 may be located outside the protective portion 21 (window portion 21b).

[0034] The synchronization unit 10, the image generation unit 11, and the determination unit 12 are physically configured by a computer system including, for example, a processor, a memory, etc. Examples of the computer system include a personal computer, a microcomputer, a cloud server, and a smart device (such as a smartphone or a tablet terminal). The image generation unit 11 may be configured by a programmable logic device (PLD) or an integrated circuit such as a field-programmable gate array (FPGA).

[0035] The synchronization unit 10 is a part that synchronizes the detection timing of the X-ray L1 in the X-ray detection unit 7 and the detection timing of the infrared ray L2 in the infrared detection unit 9. In this embodiment, the synchronization unit 10 is configured by a pulse generator and is communicatively connected to the X-ray detection unit 7 and the infrared detection unit 9 (9A, 9B). In this case, the synchronization unit 10 sets the time required for the inspection target S to be transported from the irradiation position of the infrared ray L2 to the irradiation position of the X-ray L1 as the delay time. After outputting a synchronization signal to the infrared detection unit 9, the synchronization unit 10 outputs a synchronization signal to the X-ray detection unit 7 when the delay time has elapsed from the detection time of the infrared ray L2 in the infrared detection unit 9.

[0036] The image generating unit 11 is a part that generates an inspection image of the inspection object S. The image generating unit 11 receives X-ray image data from the X-ray detection unit 7 and receives infrared image data from the infrared detection unit 9 (9A, 9B). The image generating unit 11 generates an X-ray image of the inspection object S based on the X-ray image data, and generates an infrared image of the inspection object S based on the infrared image data. The image generating unit 11 then generates a superimposed image in which the X-ray image and the infrared image are superimposed, and outputs the superimposed image to the determination unit 12 as an inspection image. When generating the superimposed image, the image generating unit 11 corrects one of the X-ray image and the infrared image so that the number of pixels of the X-ray image and the number of pixels of the infrared image match, and then superimposes the X-ray image and the infrared image.

[0037] When superimposing an X-ray image and an infrared image, it is necessary to match the pixel positions of the X-ray image and the infrared image. In this regard, in this embodiment, for example, a correction chart 25 as shown in FIG. 3 is used. The correction chart 25 is, for example, a rectangular stainless steel plate with a matrix of pores 25a. As a preliminary preparation for inspecting the inspection target S, the correction chart 25 is transported by the transport unit 5, and an X-ray image and an infrared image of the correction chart 25 are acquired. By converting the acquired X-ray image and infrared image of the correction chart 25, it is possible to match the pixel positions of the X-ray image and the infrared image. Examples of the image conversion method include affine transformation and projective transformation.

[0038] The determination unit 12 is a part that determines the presence or absence of a foreign body in the inspection object S based on the inspection image. When the determination unit 12 receives the inspection image of the inspection object S from the image generation unit 11, the determination unit 12 performs predetermined image processing or the like on the inspection image to determine the presence or absence of a foreign body. The determination unit 12 outputs information indicating the determination result together with the inspection image to the display unit 13. The display unit 13 is, for example, a display, and displays the information indicating the determination result together with the inspection image. In addition to the display unit 13, the foreign body inspection device 1 may also include an alarm unit that, when it is determined that the inspection object S contains a foreign body, notifies the fact by an alarm sound or the like.

[0039] In the foreign body inspection device 1 having the above configuration, the inspection object S transported by the inspection object S is inspected for foreign bodies by irradiating it with X-rays L1 and then by irradiating it with infrared rays L2. Therefore, compared to a case where an X-ray inspection device and an infrared inspection device are separately arranged, inspection for a wide variety of foreign bodies including hard and soft substances can be performed compactly. Also, compared to a case where an X-ray inspection device and an infrared inspection device are separately arranged, deviation of the transported object caused by the transfer of the inspection object S between the devices is reduced, and inspection accuracy can be improved. In addition, in the foreign body inspection device 1, in using both X-rays L1 and infrared rays L2, a protective unit 21 having a member that blocks X-rays L1 and transmits infrared rays L2 is provided so as to cover the infrared irradiation unit 8 and the infrared detection unit 9. Therefore, it is possible to prevent malfunctions of the infrared irradiation unit 8 and the infrared detection unit 9 caused by exposure to the X-rays L1, and to perform inspection for foreign bodies with high accuracy.

[0040] In addition, in the foreign body inspection device 1, the irradiation position of the X-ray L1 and the irradiation position of the infrared ray L2 on the inspection object S are different positions in the conveying direction, and the detection timing of the X-ray L1 in the X-ray detection unit 7 and the detection timing of the infrared ray L2 in the infrared ray detection unit 9 are synchronized by the synchronization unit 10. When the X-ray L1 and the infrared ray L2 are irradiated to the inspection object S at the same position in the conveying direction, for example, it is necessary to irradiate the inspection object S with the infrared ray L2 from directly above, while irradiating the inspection object S with the X-ray from diagonally above. In this case, if the inspection object S has a certain thickness, it is considered that the inspection position by the X-ray and the inspection position by the infrared ray will be misaligned. In contrast, in the foreign body inspection device 1, the irradiation position of the X-ray L1 and the irradiation position of the infrared ray L2 are different from each other, and the detection timing of the X-ray L1 and the detection timing of the infrared ray L2 are synchronized, so that the inspection position by the X-ray L1 and the inspection position by the infrared ray L2 can be matched even if the inspection object S has a certain thickness.

[0041] Furthermore, in the foreign substance inspection device 1, the synchronization unit 10 is configured by a pulse generator. This allows the pulse generator to generate a synchronization signal with high accuracy.

[0042] In addition, in the foreign body inspection device 1, the infrared detection units 9 (9A, 9B) respectively detect the infrared rays L2 reflected from one side and the other side of the inspection object S. This makes it possible to preferably inspect the inspection object S from one side and the other side.

[0043] Moreover, in the foreign body inspection device 1, the infrared detection unit 9 has a slit 22 arranged corresponding to the optical path of the infrared rays L2 from the inspection target S. By arranging the slit 22 in this manner, it is possible to reduce the incidence of X-rays L1 from outside the optical path of the infrared rays L2 on the infrared detection unit 9. The slit 22 may have a constant thickness or may be cylindrical. By increasing the thickness of the slit 22, it is possible to prevent the incidence of scattered X-rays and infrared stray light, and to reduce noise caused by scattered X-rays and infrared stray light. This improves the signal-to-noise ratio and improves the inspection accuracy.

[0044] Furthermore, in the foreign body inspection device 1, the image generating unit 11 generates a superimposed image by superimposing the X-ray image and the infrared image. By using such a superimposed image as an inspection image of the inspection target S, the inspection result by the X-ray L1 and the inspection result by the infrared ray L2 can be confirmed at once in the superimposed image.

[0045] FIG. 4 is a schematic diagram showing the configuration of a foreign matter inspection device according to a second embodiment of the present disclosure. As shown in the figure, a foreign matter inspection device 31 according to the second embodiment is different from the first embodiment in that an infrared detection unit 9B is configured to detect infrared rays L2 transmitted through the inspection target S. More specifically, in the foreign matter inspection device 31, the belt conveyor 14 constituting the transport unit 5 is made of a material that is transparent to infrared rays L2. In addition, the infrared irradiation unit 8B is disposed inside the belt conveyor 14 (below the transport surface). The infrared irradiation unit 8B may be protected by a material that blocks X-rays L. The infrared rays L2 emitted from the infrared irradiation unit 8B pass through the belt conveyor 14, then pass from one side to the other side of the inspection target S on the transport unit 5, and enter the infrared detection unit 9B.

[0046] In the foreign body inspection device 31, as in the first embodiment, inspection for a wide variety of foreign bodies including hard and soft substances can be performed in a compact manner. Furthermore, malfunctions in the infrared irradiator 8 and the infrared detector 9 caused by exposure to X-rays L1 are prevented, and foreign body inspection can be performed with high accuracy. In the foreign body inspection device 31, the infrared rays L2 transmitted through the inspection target S and the infrared rays L2 reflected from one side of the inspection target S are combined to inspect for foreign bodies, thereby improving the accuracy of foreign body inspection.

[0047] 4, the belt conveyor 14 is made of a material that is transparent to infrared rays L2, and the infrared irradiating unit 8B is disposed inside the belt conveyor 14, but a gap between the belt conveyors 14, 14 may be positioned at the irradiation position of the infrared rays L2 by the infrared irradiating unit 8B, so that the infrared rays L2 from the infrared irradiating unit 8B are directed toward the inspection object S without hitting the belt conveyor 14. Also, in the embodiment of FIG. 4, the infrared irradiating unit 8B irradiates the infrared rays L2 from below the inspection object S, but the infrared irradiating unit 8B may irradiate the infrared rays L2 from above the inspection object S.

[0048] FIG. 5 is a schematic diagram showing the configuration of a foreign matter inspection device according to a third embodiment of the present disclosure. FIG. 6 is a block diagram showing functional components of the foreign matter inspection device shown in FIG. 5. As shown in the figure, a foreign matter inspection device 41 according to the third embodiment differs from the first embodiment in that an inspection using ultraviolet light L3 is further combined. More specifically, the foreign matter inspection device 41 is provided with an ultraviolet light irradiation unit 42 and an ultraviolet light detection unit 43 instead of the infrared light irradiation unit 8A and the infrared light detection unit 9A. When detecting autofluorescence of the inspection target S using ultraviolet light L3, the ultraviolet light detection unit 43 may be configured with a single line sensor, a multi-line sensor, a TDI sensor, or the like capable of detecting the fluorescence (e.g., visible light).

[0049] The ultraviolet ray irradiation unit 42 and the ultraviolet ray detection unit 43 are disposed in the protective unit 44. Here, the main body portion 44a of the protective unit 44 is formed of a material such as lead capable of blocking X-rays L1, and the window portion 44b of the protective unit 44 is formed of a material that blocks X-rays L1 and transmits ultraviolet rays L3. Inside the protective unit 44, a slit 45 is disposed near the detection surface of the ultraviolet ray detection unit 43. The slit 45 may have a constant thickness, similar to the slit 22, and may be cylindrical. The tip of the slit 45 may be located outside the protective unit 44 (window portion 44b). The rear end of the slit 45 may be located outside the protective unit 44 (window portion 44b). That is, the entire slit 45 may be located outside the protective unit 44 (window portion 44b).

[0050] A portion of the ultraviolet light L3 emitted upward from the ultraviolet light irradiation unit 42 is reflected by one side of the inspection object S on the transport unit 5, and then enters the ultraviolet light detection unit 43. The ultraviolet light detection unit 43 outputs ultraviolet light image data based on the detection result. The image generation unit 11 generates a superimposed image by superimposing an X-ray image based on the X-ray image data, an infrared image based on the infrared image data, and an ultraviolet light image based on the ultraviolet image data, and outputs the superimposed image to the determination unit 12 as an inspection image of the inspection object S.

[0051] In the foreign body inspection device 41, as in the first embodiment, a wide variety of foreign bodies including hard and soft substances can be inspected in a compact manner. Moreover, problems caused by exposure to X-rays L1 in the infrared irradiator 8, the infrared detector 9, the ultraviolet irradiator 42, and the ultraviolet detector 43 can be prevented, and foreign body inspection can be performed with high accuracy. By using ultraviolet light L3, it becomes possible to detect, for example, the autofluorescence of the inspection target S, and an even wider variety of foreign bodies can be inspected.

[0052] FIG. 7 is a diagram showing the correspondence between inspection methods and foreign bodies that can be inspected. The diagram summarizes the foreign bodies that can be inspected for four inspection methods: metal detectors, X-ray detection devices, infrared detection devices, and ultraviolet (autofluorescence) detection devices. Metal detectors are a reference example. In the diagram, "A" means that inspection is possible, "B (B1 to B3)" means that inspection is possible under certain conditions, and "C" means that inspection is difficult. Metal detectors can detect iron / SUS. X-ray detection devices can detect iron / SUS, stone, glass, rubber, and voids.

[0053] The infrared detection device can detect iron / SUS, stone, rubber, plastic, moisture, mold, and hair. It is difficult to detect transparent glass, but it is possible to detect semi-transparent glass (B1 in FIG. 7). Air bubbles can be detected when the package of the object to be inspected is transparent (B2 in FIG. 7). The ultraviolet (autofluorescence) detection device can detect dust and feathers, and can also be applied to the detection of cartilage of chickens. In addition, mold can be detected depending on the type (B3 in FIG. 7). Therefore, it can be seen that a wide variety of foreign bodies, including hard and soft substances, can be inspected by performing an inspection using a combination of X-rays L1 and infrared rays L2, or by further performing an inspection using ultraviolet rays L3, as in the first to third embodiments described above.

[0054] The present disclosure is not limited to the above embodiment. For example, in the above embodiment, the synchronization unit 10 is configured by a pulse generator, but the synchronization unit 10 may be configured by an encoder. In this case, the encoder detects the amount of movement of the inspection target S in the transport unit 5, and outputs a synchronization signal to the X-ray detection unit 7 when the inspection target S is transported from the irradiation position of the infrared ray L2 to the irradiation position of the X-ray L1. Also, without using a pulse generator or an encoder, a synchronization signal may be output from the X-ray detection unit 7 to the infrared detection unit 9, or a synchronization signal may be output from the infrared detection unit 9 to the X-ray detection unit 7. The same applies to the case where the ultraviolet detection unit 43 is arranged.

[0055] In each of the above embodiments, which side of the inspection object S on the transport unit 5 the X-rays L1, the infrared rays L2, and the ultraviolet rays L3 are irradiated from can be appropriately changed depending on the type, shape, etc. of the inspection object S. For example, in each of the above embodiments, the X-rays L1 that have passed through the inspection object S from the other side to one side are detected, but the X-rays L1 that have passed through the inspection object S from the one side to the other side may also be detected.

[0056] The number of infrared detection units 9 arranged is not limited to two, and may be one, or three or more. When a plurality of infrared detection units 9 are arranged, a synchronization signal may be output from one infrared detection unit 9 to the other infrared detection units 9 to achieve synchronization. The image generation unit 11 may perform a process of matching the number of pixels of each inspection image of the inspection object S, as well as a process of making each inspection image dimensionless and matching the ratio between them.

[0057] In the second embodiment shown in FIG. 4, the infrared rays L2 reflected on one side of the object S to be inspected and the infrared rays L2 transmitted from one side of the object S to the other side are detected, but the infrared rays L2 reflected on the other side of the object S to be inspected and the infrared rays L2 transmitted from one side of the object S to the other side may be detected, or the infrared rays transmitted from the other side of the object S to the one side may be detected. The same applies to the detection of the ultraviolet rays L3. In addition, a configuration for detecting the infrared rays L2 reflected on one side of the object S to be inspected may be added to the second embodiment shown in FIG. 4.

[0058] In each of the above embodiments, the X-rays L1, the infrared rays L2, and the ultraviolet rays L3 are irradiated onto the inspection target S from above or below (so-called vertical irradiation), but the inspection direction is not limited to this. For example, the X-rays L1, the infrared rays L2, and the ultraviolet rays L3 may be irradiated onto the inspection target S from the side (so-called horizontal irradiation).

[0059] In the above embodiment, the protective part 21 is configured to cover the infrared ray irradiating part 8 and the infrared ray detecting part 9. However, as shown in FIG. 8(a), the protective part 21 may be configured by a protective part 21A that covers the infrared ray irradiating part 8 and a protective part 21B that covers the infrared ray detecting part 9. With such a configuration, it is possible to prevent the infrared ray L2 emitted from the infrared ray irradiating part 8 from being reflected inside the protective part 21 and being directly detected by the infrared ray detecting part 9. The same is true for the protective part 44, and as shown in FIG. 8(b), the protective part 44 may be configured by a protective part 44A that covers the ultraviolet ray irradiating part 42 and a protective part 44B that covers the ultraviolet ray detecting part 43. With such a configuration, it is possible to prevent the ultraviolet ray L3 emitted from the ultraviolet ray irradiating part 42 from being reflected inside the protective part 44 and being directly detected by the ultraviolet ray detecting part 43.

[0060] An infrared multi-line sensor 17A having sensitivity to different wavelength ranges may be used as the infrared line sensor 17 constituting the infrared detection unit 9. As shown in Fig. 9(a), the infrared multi-line sensor 17A has an infrared line sensor 171a and an infrared line sensor 172a arranged at a predetermined interval by a dead zone. The infrared multi-line sensor 17A is arranged so that the extension direction of the infrared line sensor 171a and the infrared line sensor 172a is perpendicular to the transport direction of the inspection target S.

[0061] 9(b), an optical filter 171b that transmits infrared light in a first infrared wavelength range is disposed on the infrared line sensor 171a, and an optical filter 172b that transmits infrared light in a second infrared wavelength range is disposed on the infrared line sensor 172a. The first infrared wavelength range is, for example, 900 nm or more and 1400 nm or less. The second infrared wavelength range is, for example, 1400 nm or more and 1700 nm or less.

[0062] In the case of infrared multi-line sensor 17A, for example, when detecting insects, plastic, wood chips, rubber, etc. in food as foreign objects, it becomes easy to distinguish between food and foreign objects (insects, plastic, rubber, etc.) by taking the ratio or difference between an infrared image with a wavelength of 900 nm or more and 1400 nm or less and an infrared image with a wavelength of 1400 nm or more and 1700 nm or less. This is because the infrared absorbance of food changes significantly in the wavelength range of 1400 nm or more, while the absorbance of foreign objects does not change significantly in the same range. Note that the first infrared wavelength range and the second infrared wavelength range may partially overlap each other.

[0063] In the infrared multi-line sensor 17A, a first control pulse for controlling imaging by the infrared line sensor 17a and a second control pulse for controlling imaging by the infrared line sensor 172a may be set based on the width of the dead zone and the transport speed of the inspection object S. In this case, the frequency of the first control pulse and the frequency of the second control pulse may be set based on the width of the dead zone and the transport speed of the inspection object S, and the delay time of the rise of the first control pulse relative to the rise of the second control pulse may be set based on the width of the dead zone and the transport speed of the inspection object S. This makes it possible to obtain infrared images at the same position of the inspection object S using different wavelengths.

[0064] In addition, an infrared multi-line sensor 17B having sensitivity to a different wavelength range may be used as the infrared line sensor 17 constituting the infrared detection unit 9. As shown in Fig. 10(a), the infrared multi-line sensor 17B has an infrared line sensor 171a, an infrared line sensor 172a, and an infrared line sensor 173a arranged at a predetermined interval by a dead zone. The infrared multi-line sensor 17A is arranged so that the extension direction of the infrared line sensor 171a, the infrared line sensor 172a, and the infrared line sensor 173a is perpendicular to the transport direction of the inspection target S.

[0065] As shown in FIG. 10(b), an optical filter 171b that transmits infrared rays in a first infrared wavelength range is disposed on the infrared line sensor 171a, an optical filter 172b that transmits infrared rays in a second infrared wavelength range is disposed on the infrared line sensor 172a, and an optical filter 173b that transmits infrared rays in a third infrared wavelength range is disposed on the infrared line sensor 173a. The first infrared wavelength range is, for example, 900 nm or more and 1200 nm or less. The second infrared wavelength range is, for example, 1200 nm or more and 1400 nm or less. The third infrared wavelength range is, for example, 1400 nm or more and 1700 nm or less.

[0066] In the case of infrared multi-line sensor 17B, for example, when detecting insects, multiple types of plastics, wood chips, rubber, etc. in food as foreign objects, by taking the ratio or difference between an infrared image with a wavelength of 900 nm or more and 1200 nm or less, an infrared image with a wavelength of 1200 nm or more and 1400 nm or less, and an infrared image with a wavelength of 1400 nm or more and 1700 nm or less, it becomes easy to distinguish between food and foreign objects (insects, plastics, rubber, etc.), and it becomes possible to distinguish between types of insects, multiple types of plastics, wood chips, rubber, etc. in food. Note that the first infrared wavelength range and the second infrared wavelength range may partially overlap, and the second infrared wavelength range and the third infrared wavelength range may partially overlap. [Explanation of symbols]

[0067] 1, 31, 41...foreign body inspection device, 5...conveyor section, 6...X-ray irradiation section, 7...X-ray detection section, 8 (8A, 8B)...infrared irradiation section, 9 (9A, 9B)...infrared detection section, 10...synchronization section, 11...image generation section, 21 (21A, 21B), 44 (44A, 44B)...protection section, 22...slit, 42...ultraviolet irradiation section, 43...ultraviolet detection section, L1...X-ray, L2...infrared, L3...ultraviolet, S...object to be inspected.

Claims

1. A foreign matter inspection device that inspects an object for the presence or absence of a foreign matter, comprising: A conveying unit that conveys the inspection object in a predetermined conveying direction; an X-ray irradiation unit that irradiates the inspection object transported by the transport unit with X-rays; an X-ray detection unit that detects the X-rays transmitted through the inspection object and outputs X-ray image data based on the detection result; an infrared ray irradiating unit that irradiates the inspection object transported by the transport unit with infrared rays; an infrared detection unit that detects the infrared rays from the inspection object and outputs infrared image data based on the detection result; a protective portion provided to cover the infrared ray irradiation portion and the infrared ray detection portion; an image generating unit that generates an X-ray image of the inspection object based on the X-ray image data and generates an infrared image of the inspection object based on the infrared image data, a window portion formed of a material that blocks X-rays and transmits infrared rays, the window portion being located in an optical path of the infrared rays;

2. an irradiation position of the X-ray and an irradiation position of the infrared ray on the inspection object are different positions with respect to the conveying direction; 2. The foreign body inspection device according to claim 1, wherein a detection timing of the X-rays in the X-ray detection section and a detection timing of the infrared rays in the infrared detection section are synchronized.

3. 3. The foreign body inspection device according to claim 2, wherein the X-ray detection section outputs a synchronization signal to the infrared detection section in response to a detection timing of the X-rays.

4. 3. The foreign body inspection device according to claim 2, wherein the infrared detection section outputs a synchronization signal to the X-ray detection section in response to a detection timing of the infrared rays.

5. 3. The foreign body inspection device according to claim 2, further comprising a synchronization unit that synchronizes a detection timing of the X-rays in the X-ray detection unit with a detection timing of the infrared rays in the infrared detection unit.

6. 6. The foreign matter inspection device according to claim 5, wherein the synchronization unit is constituted by a pulse generator.

7. 6. The foreign matter inspection device according to claim 5, wherein the synchronization section is constituted by an encoder that detects the amount of movement of the inspection object in the transport section.

8. 8. The foreign body inspection device according to claim 1, wherein the infrared detection section detects at least one of the infrared rays reflected from the inspection object and the infrared rays transmitted through the inspection object.

9. 9. The foreign body inspection device according to claim 1, wherein the infrared detection section has a slit disposed in correspondence with an optical path of the infrared ray from the inspection object.

10. 10. The foreign body inspection device according to claim 1, wherein the image generating section generates a superimposed image by superimposing the X-ray image and the infrared image.

11. 11. The foreign body inspection device according to claim 10, wherein the image generating unit corrects one of the X-ray image and the infrared image so that the number of pixels of the X-ray image and the number of pixels of the infrared image match, and then superimposes the X-ray image and the infrared image.

12. an ultraviolet ray irradiation unit that irradiates the inspection object transported by the transport unit with ultraviolet rays; an ultraviolet ray detection unit that detects the ultraviolet ray from the inspection object and outputs ultraviolet ray image data based on the detection result; 12. The foreign body inspection device according to claim 1, further comprising: a protective section having a member that blocks the X-rays and transmits the ultraviolet rays, the protective section being arranged to cover the ultraviolet ray irradiation section and the ultraviolet ray detection section.

Images