Flying spot scanning device and ray inspection system

Abstract

The invention provides a flying spot scanning device and a ray inspection system. The flying spot scanning device comprises n ray sources and n # imgabs0 #, the flying spot device comprises a flywheel, n fan-shaped boxes and n groups of beam holes, the n fan-shaped boxes and the n groups of beam holes are in one-to-one correspondence with the n ray sources, the n fan-shaped boxes are all arranged in a preset angle area of the flywheel and are staggered in the circumferential direction of the flywheel, and light emitting angles of the n fan-shaped boxes cover the whole preset angle area, the number of the beam holes in each group is equal to 360 degrees / the corresponding light emitting angle of the fan-shaped box, and rays emitted by the n ray sources are sequentially emitted from the flying spot device. Therefore, under-sampling risks in the flying spot scanning process can be reduced under the condition that the scanning range of the flying spot scanning device is not reduced.

Description

Technical Field

[0001] The present application relates to the field of inspection technology, and in particular to a flying spot scanning device and a ray inspection system. Background Art

[0002] Some X-ray inspection systems use a X-ray source, a flying spot device, and a detector to perform flying spot scanning on the object to be inspected to obtain an image of the object.

[0003] In practice, it is found that it is easy to miss scans during the flying spot scanning process, causing undersampling problems. Summary of the Invention

[0004] A technical problem to be solved by the present application is to solve the undersampling problem in the flying spot scanning process without reducing the scanning range of the flying spot scanning device.

[0005] In order to solve the above technical problems, the present application provides a flying spot scanning device, which includes:

[0006] n ray sources, n ;and

[0007] A flying spot device includes a flywheel, n sector boxes, and n groups of beam holes. The n sector boxes and the n groups of beam holes each correspond one-to-one to n radiation sources. The light emission angles of the n sector boxes are all located within a preset angle region of the flywheel and are staggered in a circumferential direction of the flywheel. The light emission angles of the n sector boxes cover the entire preset angle region. The number of beam holes in each group of beam holes is equal to 360° / the light emission angle of the corresponding sector box. Rays emitted by the n radiation sources are sequentially emitted from the flying spot device.

[0008] In some embodiments, the light emission angles of the fan-shaped boxes are the same or different.

[0009] In some embodiments, the light emission angle of each fan-shaped box is 1 / n of a preset angle.

[0010] In some embodiments, the n ray sources are located on the same plane perpendicular to the relative movement direction of the object under test and the flying spot scanning device; or, the n ray sources are arranged in sequence along the relative movement direction of the object under test and the flying spot scanning device.

[0011] In some embodiments, the radiation source emits a beam continuously or discontinuously.

[0012] In some embodiments, the radiation source is pulsed.

[0013] In some embodiments, n ray sources emit beams sequentially.

[0014] In some embodiments, the n groups of beam holes are disposed on the same flywheel, or the n groups of beam holes are disposed on different flywheels.

[0015] In some embodiments, the n radiation sources are n X-ray machines, or the n radiation sources are n targets on the same X-ray machine.

[0016] In some embodiments, each ray source emits multiple beams within the light emission angle range of its corresponding fan-shaped box.

[0017] In addition, the present application also provides a radiographic inspection system, which includes a detector and also includes a flying spot scanning device according to any embodiment. The flying spot scanning device cooperates with the detector to perform flying spot scanning on the object to be inspected.

[0018] In some embodiments, the detector includes a backscatter detector and / or a transmission detector.

[0019] By arranging n(n ) ray sources, and each ray source is equipped with a corresponding sector box and a group of beam holes, and the n sector boxes are arranged in a preset angle area of the flywheel and staggered in the circumferential direction of the flywheel, the light emission angles of the n sector boxes cover the entire preset angle area, the number of beam holes in each group of beam holes is equal to 360° / the light emission angle of the corresponding sector box, and the rays emitted by the n ray sources are emitted sequentially from the flying spot device, which can effectively reduce the column spacing and reduce the risk of undersampling without reducing the scanning range of the flying spot scanning device.

[0020] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 It is a schematic diagram of the cooperation between the flying spot scanning device and the backscatter detector in the related art.

[0023] Figure 2 for Figure 1 Front view of the mid-flight spot scanning device.

[0024] Figure 3 for Figure 1 Side view of the mid-flight spot scanner.

[0025] Figure 4 Schematic diagram of the cooperation between the flying spot scanning device and the backscatter detector in the embodiment of the present application.

[0026] Figure 5 for Figure 4 Front view of the mid-flight spot scanning device.

[0027] Figure 6 for Figure 4 Side view of the mid-flight spot scanner.

[0028] Figure 7 for Figure 4 Schematic diagram of the beam-emission relationship of each ray source.

[0029] Figure 8 Schematic diagram of the beam-emitting relationship of each ray source in a variant example of the present application.

[0030] Figure 9 This is a schematic diagram of the cooperation between the flying spot scanning device and the backscatter detector in another variant of the present application.

[0031] Description of reference numerals:

[0032] 1. Flying spot scanning device; 11. Ray source; 12. Flying spot device; 13. Flywheel; 14. Sector box; 15. Beam aperture;

[0033] 2. Detector; 21. Backscatter detector. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without carrying out creative work are within the scope of protection of this application.

[0035] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0036] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0037] In the description of this application, it should be understood that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0038] In the present application, unless otherwise specified, "a plurality of" means at least two, that is, including cases of two and at least three.

[0039] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0040] As a typical structure of a radiographic inspection system, the radiographic inspection system includes a flying spot scanning device and a detector. The flying spot scanning device includes a radiation source and a flying spot device. The flying spot device includes a sector box and a flywheel. The flywheel is rotatably arranged relative to the sector box. A plurality of beam holes are provided on the edge of the flywheel. The sector box has a collimating slit. The collimating slit on the sector box and the beam holes on the flywheel constrain the radiation beam emitted by the radiation source into a pencil beam. During the high-speed rotation of the flywheel, only one beam hole can emit a photon beam at the same time, forming a pencil beam and performing a one-dimensional high-speed line scan in a first direction. At the same time, the object under test and the radiation source move relative to each other in a second direction different from the first direction, thereby obtaining a two-dimensional backscattered image of the object under test and realizing the flying spot scanning process.

[0041] In practice, it is found that the above-mentioned X-ray inspection system has an undersampling problem during the flying spot scanning process, and is prone to missing scans.

[0042] Further research revealed that an important reason for the undersampling problem in the flying spot scanning process is that the flying spot device is only equipped with one ray source, that is, a single-ray source flying spot design is adopted.

[0043] Specifically, if Figure 1-Figure 3As shown, in the related art, the flying spot device 12 cooperates with only one radiation source 11 to perform flying spot scanning on an unillustrated object in a vertical plane along a first direction. It is understood that the flying spot device 12 can also be configured to perform flying spot scanning in other planes, such as a horizontal plane, along the first direction. For simplicity, the following description uses the example of a case where the flywheel 13 of the flying spot device 12 rotates in a vertical plane, and the relative movement direction of the object under test and the flying spot scanning device 1 is a horizontal second direction. During the scanning process, due to the relative movement of the object under test and the flying spot scanning device 1, multiple columns of light beams spaced apart along the second direction are formed on the object under test. Research has found that when using a single-source flying spot scanning device, the diameter of the projected light spot of the light beam on the object under test is often smaller than the spacing between the columns of light beams, resulting in the portion between the columns of light beams not being covered by the projected light spot. That is to say, a part of the part of the object under inspection located between each column of light beams will not be scanned, thus causing missed scanning and undersampling. The corresponding problem is more serious in a high-speed and high-throughput X-ray inspection system (for example, the relative movement speed of the object under inspection and the flying spot scanning device 1 is 15 km / h).

[0044] Regarding the above-mentioned undersampling problem, although the undersampling risk can be reduced by increasing the rotation speed of the flywheel 13 of the flying spot device 12, the flying spot device 12 has a complex mechanical structure, and increasing the flywheel rotation speed is technically difficult and poses a high safety hazard.

[0045] In the related art, the maximum speed of the flywheel 13 is usually 2000-3000 rpm. Here, the case where the flywheel speed is 2000 rpm and the beam angle of the fan-shaped box 14 is 120° is used as an example for explanation. When the flywheel 13 speed is 2000 rpm, assuming that three beam holes 15 with a diameter of 3.5 mm are evenly arranged on the flywheel 13, the interval time of each beam column is 10 ms ( ), and the spot diameter at 2 meters away from the radiation source is about 10mm. If a flywheel with this rotation speed is used, when the inspection speed (the relative movement speed of the inspected object and the flying spot scanning device 1) is 5km / h, the beam column spacing at the inspected object 2m away from the radiation source is about 14mm (the interval time between each beam column is 10ms×the inspection speed is 5km / h), which is slightly larger than the spot diameter. At this time, it can be considered that there is no undersampling problem; and when the inspection speed is 15km / h, the beam column spacing at the inspected object 2m away from the radiation source is about 42mm (the interval time between each beam column is 10ms×the inspection speed is 15km / h), which is much larger than the spot diameter. At this time, there is a very serious undersampling problem, and the faster the inspection speed, the more serious the undersampling problem. In order to solve the undersampling problem when the inspection speed is 15km / h, the flywheel speed can be increased, but the flywheel speed needs to be increased to 6000rpm (the interval time between each beam column is ms) to obtain a beam column spacing of about 14 mm, but it is very difficult to manufacture a flywheel with such a rotation speed.

[0046] As another way to solve the undersampling problem at an inspection speed of 15 km / h, for example, a flying spot scanning device can be used with a flywheel speed of 2000 rpm, a beam angle of 40° for the fan-shaped box 14, and correspondingly 9 beam holes 15 with a diameter of 3.5 mm evenly arranged on the flywheel 13 for scanning; in this case, the interval time of each beam column is ms( ), the beam spacing is about 14 mm (the interval between each beam) when the object is 2 m away from the radiation source. ms×inspection speed 15 km / h). However, the light emission angle of the sector box 14 is too small, so the scanning range in the first direction is limited, and the object to be inspected cannot be completely scanned at one time.

[0047] Therefore, how to solve the undersampling problem in the flying spot scanning process without reducing the scanning range of the flying spot scanning device becomes a difficult problem.

[0048] In view of the above situation, the present application provides a flying spot scanning device and a ray inspection system.

[0049] Figure 4-Figure 9 The structure and beam emission mode of the flying spot scanning device and the ray inspection system of the present application are exemplarily shown.

[0050] See also Figure 4-Figure 9 In the embodiment of the present application, the radiographic inspection system includes a detector 2 and a flying spot scanning device 1. The flying spot scanning device 1 cooperates with the detector 2 to perform flying spot scanning on the object to be inspected (not shown). The flying spot scanning device 1 includes a flying spot device 12 and n (n ) radiation sources 11. The flying spot device 12 includes a flywheel 13, n sector boxes 14, and n groups of beam holes 15. Each of the n sector boxes 14 and the n groups of beam holes 15 corresponds one-to-one to the n radiation sources 11. The emission angles of the n sector boxes 14 are all located within a preset angle range of the flywheel 13 and are staggered in the circumferential direction of the flywheel 13. The emission angles of the n sector boxes 14 (that is, the angles of the collimating slits of each sector box 14) cover the entire preset angle range. The number of beam holes 15 in each group of beam holes 15 is equal to 360° / the emission angle of the corresponding sector box 14. The radiation emitted by the n radiation sources 11 is sequentially emitted from the flying spot device 12.

[0051] In the above scheme, n (n , that is, multiple) ray sources 11, and each ray source 11 is equipped with a corresponding sector box 14 and a group of beam holes 15. This is no longer a single-light source flying spot scanning method, but a multi-light source flying spot scanning method. The multiple light sources sequentially irradiate the object under test, and the n sector boxes 14 corresponding to the multiple light sources are all arranged within a preset angle area of the flywheel 13 and staggered in the circumferential direction of the flywheel 13. The light output angles of the n sector boxes 14 cover the entire preset angle area. The number of beam holes 15 in each group of beam holes 15 is equal to 360° / the light output angle of the corresponding sector box 14. The rays emitted by the n ray sources 11 are sequentially emitted from the flying spot device 12. In this way, without reducing the light output angle (or scanning range) of the flying spot device 12, segmented scanning of the object to be inspected in the circumferential direction of the flywheel 13 can be achieved, thereby accelerating the scanning speed, reducing the beam column spacing, and narrowing or even eliminating the gap between the diameter of the light spot projected by the light beam on the object to be inspected and the beam column spacing. This allows the portion of the object to be inspected located between the beam column spacings to be scanned, reducing missed scans, and thus effectively solving the undersampling problem and reducing the risk of undersampling.

[0052] Furthermore, since the above solution can reduce the risk of undersampling without increasing the flywheel speed, it can reduce technical difficulty and minimize safety hazards.

[0053] It can be seen that by arranging n ray sources 11 in the flying spot scanning device 1, and equipping each ray source 11 with a corresponding sector box 14 and a group of beam holes 15, and making the n sector boxes 14 all arranged in the preset angle area of the flywheel 13, and staggered in the circumferential direction of the flywheel 13, and the light output angles of the n sector boxes 14 cover the entire preset angle area, the number of beam holes 15 in each group of beam holes 15 is equal to 360° / the light output angle of the corresponding sector box 14, the rays emitted by the n ray sources 11 are emitted from the flying spot device 12 in sequence, and high-speed scanning can be achieved without increasing the flywheel speed, reducing the column spacing, reducing the risk of undersampling, being simple, convenient and highly safe.

[0054] Among them, n groups of beam holes 15 can be set on the same flywheel 13 (see Figure 4 ) or on different flywheels 13 (see Figure 9 When n groups of beam holes 15 are provided on the same flywheel 13, the number of flywheels 13 in the flying spot device 12 is small, and thus the structure is simpler, the cost is lower, and the space occupied is less.

[0055] In addition, various means may be used to enable the rays emitted by the n ray sources 11 to be emitted from the flying spot device 12 in sequence.

[0056] For example, the beam emission mode of each ray source 11 can be controlled so that the rays emitted by each ray source 11 are sequentially emitted from their corresponding beam holes 15, thereby realizing the sequential emission of rays emitted by n ray sources 11 from the flying spot device 12. This method is applicable to the case where n groups of beam holes 15 are arranged on the same flywheel 13, and is also applicable to the case where n groups of beam holes 15 are arranged on different flywheels 13, and has a wider range of applicability.

[0057] In order to control the beam emission mode of each ray source 11 so that the rays emitted by the n ray sources 11 are sequentially emitted from the flying-spot device 12, in some embodiments, the n ray sources 11 emit beams sequentially. In this case, it is only necessary to control the beam emission timing of each ray source 11 so that each ray source 11 emits beams in a time-sharing manner, without requiring any special control over the rotation of the flywheel 13 (for example, without requiring that different flywheels 13 rotate to the beam emission position at different times). This allows the rays emitted by the n ray sources 11 to be sequentially emitted from the flying-spot device 12, which is simple and convenient.

[0058] It can be seen that the rays emitted by the n ray sources 11 are emitted from the flying spot device 12 in sequence, including the case where each ray source 11 emits a beam in a time-sharing manner, and the case where each ray source 11 emits a beam at the same time but the rays emitted by each ray source 11 are not emitted from the beam hole 15 at the same time.

[0059] In the aforementioned embodiments, the form of the radiation source 11 is not limited. For example, the radiation source 11 can be an X-ray machine or a target. For another example, the radiation source 11 can emit beams continuously or discontinuously.

[0060] As an example, in some embodiments, the n radiation sources 11 are n X-ray machines, and each X-ray machine is a pulsed X-ray machine. In this case, each radiation source 11 is an X-ray machine, and each radiation source 11 is a pulsed radiation source, performing pulsed beam emission, thereby implementing a discontinuous beam emission method. In other embodiments, the n radiation sources 11 are n targets on the same X-ray machine, and the X-ray machine is a pulsed X-ray machine. In this case, each radiation source 11 is a target of the X-ray machine, and each radiation source 11 is a pulsed radiation source, performing pulsed beam emission, thereby implementing a discontinuous beam emission method. For another example, in some embodiments, the n radiation sources 11 are n X-ray machines, and each X-ray machine is a continuous beam emission X-ray machine. These n continuous beam emission X-ray machines are controlled to emit pulsed beams by a mechanical shutter, etc. In this case, each radiation source 11 is an X-ray machine, and each radiation source 11 is a continuous beam emission X-ray machine, and pulsed beam emission is achieved by a mechanical shutter, etc., thereby implementing a discontinuous beam emission method.

[0061] It can be seen that no matter the ray source 11 is an X-ray machine, a target, a continuous ray source, or a discontinuous ray source such as a pulsed ray source, discontinuous beam emission such as pulsed beam emission can be performed.

[0062] When the radiation source 11 is pulsed, it is convenient to control the timing of the beam emission of each radiation source 11 so that each radiation source 11 emits a beam in sequence, rather than simultaneously. This facilitates the sequential emission of radiation from the flying-spot device 12 by the n radiation sources 11. This is particularly convenient for controlling the sequential emission of radiation from the flying-spot device 12 without any special control of the flywheel 13, thereby effectively increasing the scanning speed, reducing the beam column spacing, and reducing the risk of undersampling.

[0063] In the aforementioned embodiments, the light emission angle of each sector box 14 (that is, the angle of the collimating slit of each sector box 14 ) can be set in a variety of ways.

[0064] For example, the light emitting angles of the fan-shaped boxes 14 may be the same or different. When the light emitting angles of the fan-shaped boxes 14 are the same, the structure is simpler and the arrangement is more convenient.

[0065] As an example of the same light emitting angle of each fan-shaped box 14, see Figure 4-Figure 6 In some embodiments, the beam output angle of each sector-shaped box 14 is 1 / n of a preset angle. For example, if the preset angle (e.g., the beam output angle of the sector-shaped box 14 when the flying spot scanning device 1 employs a single light source) is 120°, then when the flying spot scanning device 1 includes n radiation sources 11, the beam output angle of each sector-shaped box 14 is 120° / n. In this way, the sum of the beam output angles of the sector-shaped boxes 14 corresponding to the multiple radiation sources is exactly equal to the beam output angle of the sector-shaped box 14 when the flying spot scanning device 1 employs a single radiation source. This ensures that the scanning range of the multi-ray source flying spot scanning device is the same as that of the single-ray source flying spot scanning device, with neither missed scans nor duplicate scans (or repeated scans). This effectively resolves the undersampling issue while further reducing the difficulty of data processing in the subsequent image generation process, achieving a more accurate and efficient scanning process.

[0066] In the aforementioned embodiments, the staggered arrangement of the sector-shaped boxes 14 along the circumference of the flywheel 13 allows the beam angles corresponding to the respective radiation sources 11 to be staggered circumferentially. This prevents the beam angles corresponding to the respective radiation sources 11 from completely overlapping circumferentially, which would reduce the scanning range and affect scanning efficiency. The staggered arrangement of the sector-shaped boxes 14 along the circumference of the flywheel 13 can be either completely staggered or partially staggered (also referred to as a staggered arrangement). When the sector-shaped boxes 14 are completely staggered along the circumference of the flywheel 13, the beam angles corresponding to the respective radiation sources 11 do not overlap circumferentially, preventing repeated scanning of the same area of the object under inspection. This reduces the risk of undersampling, reduces the amount of data, and eases the difficulty of subsequent image processing.

[0067] In the aforementioned embodiments, the positional relationship between the n ray sources 11 can be varied. For example, in some embodiments, the n ray sources 11 are located on the same plane perpendicular to the relative movement direction of the object under test and the flying spot scanning device 1. In this case, each ray source 11 is at the same position in the relative movement direction of the object under test and the flying spot scanning device 1. For another example, see Figure 4-Figure 5 In some embodiments, n radiation sources 11 are sequentially arranged along the relative moving direction of the object under test and the flying spot scanning device 1. In this case, the radiation sources 11 are staggered in the relative moving direction of the object under test and the flying spot scanning device 1.

[0068] It will be understood that the relative movement direction of the object under test and the flying spot scanning device 1 refers to the relative movement direction of the object under test and the flying spot scanning device 1 along the length of the inspection channel. The relative movement of the object under test and the flying spot scanning device 1 can be achieved by moving one of the object under test and the flying spot scanning device 1 while the other remains stationary, or by moving both the object under test and the flying spot scanning device 1 at different speeds. When the object under test moves, it can move by its own power or by being driven by an external towing mechanism. For example, in some embodiments, the object under test is a vehicle. In this case, the object under test can move by its own movement. In this case, the relative movement direction of the object under test and the flying spot scanning device 1 is the direction of travel of the vehicle.

[0069] See also Figure 6-Figure 8 In the aforementioned embodiments, each ray source 11 may emit only one beam within the angular range of the corresponding sector box 14, or may emit multiple (i.e., at least two) beams. When each ray source 11 emits multiple beams within the angular range of the corresponding sector box 14, efficiency and accuracy are improved.

[0070] It should be noted that, in each embodiment of the present application, the form of the detector 2 is not limited. It can include only a backscatter detector 21 to perform backscatter flying spot scanning, or it can include only a transmission detector (not shown) to perform transmission flying spot scanning, or it can also include both the backscatter detector 21 and the transmission detector to perform backscatter flying spot scanning and transmission flying spot scanning.

[0071] Next, combine Figure 4-Figure 9 The embodiments shown are used to further introduce the present application.

[0072] First, let’s introduce Figure 4-Figure 7 The embodiment shown.

[0073] In this embodiment, the radiographic inspection system includes at least one inspection device, which is arranged on at least one side of an inspection channel (not shown) and includes a detector 2 and a flying spot scanning device 1 including a flying spot device 12 to perform flying spot scanning on the object to be inspected at at least one viewing angle.

[0074] Specifically, in this embodiment, the X-ray inspection system includes multiple inspection devices, which are arranged on different sides of the inspection channel and include a detector 2 and a flying spot scanning device 1 having a flying spot device 12 to perform flying spot scanning on the object to be inspected at multiple viewing angles.

[0075] More specifically, in this embodiment, the detector 2 of each inspection device includes a backscatter detector 21 , and the flying spot scanning device 1 and the backscatter detector 21 of the same inspection device perform backscatter flying spot scanning on the inspection object at one side of the inspection object.

[0076] During operation, the inspection device does not move along the length of the inspection channel, but the object to be inspected (such as a vehicle) moves along the length of the inspection channel. In this way, the object to be inspected and the flying spot scanning device 1 move relative to each other, and the relative movement direction of the object to be inspected and the flying spot scanning device 1 is the length of the inspection channel.

[0077] In this embodiment, the structures of the inspection devices are the same.

[0078] Figure 4-Figure 6 The structure of each inspection device in this embodiment is shown.

[0079] like Figure 4-Figure 6 As shown, in this embodiment, each inspection device includes a flying spot scanning device 1 and two backscatter detectors 21. The two backscatter detectors 21 are arranged on opposite sides of the flying spot scanning device 1 and are used to receive backscattered radiation emitted from the flying spot scanning device 1 to the inspected object (e.g., a vehicle) and reflected from the inspected object. The flying spot scanning device 1 includes a flying spot device 12 and two (i.e., n = 2) radiation sources 11. The flying spot device 12 includes a flywheel 13 and two sector boxes 14. The edge of the flywheel 13 is provided with two sets of beam holes 15.

[0080] The two ray sources 11 are both pulse X-ray machines, and are arranged side by side with an interval between them along the length direction of the inspection channel (ie, the relative movement direction of the inspection object and the flying spot scanning device 1 ).

[0081] The flywheel 13 is rotatably arranged and includes a wheel disc and a rim arranged around the outer circumference of the wheel disc.

[0082] Two sector boxes 14 are positioned radially inward of the wheel rim and are non-rotatable, allowing the flywheel 13 and the two sector boxes 14 to rotate relative to each other. Each sector box 14 has a collimating slit (not shown) located on its radial outer edge for radiation to pass through. The collimating slit is arc-shaped, and its circumferential angle represents the beam output angle of the sector box 14. Furthermore, in this embodiment, the two sector boxes 14 are spaced apart along the length of the inspection channel, corresponding one-to-one with the two radiation sources 11 along the length of the inspection channel. At the same time, the two sector boxes 14 are arranged in the preset angle area of the flywheel 13 and are adjacent to each other in the circumferential direction of the flywheel 13 (that is, the sector boxes 14 are completely staggered in the circumferential direction, and there is no circumferential gap between the two circumferentially adjacent sector boxes 14), just covering the entire preset angle area of the flywheel 13, and the light output angle of each sector box 14 is half of the preset angle (that is, 1 / n). For example, if the preset angle area is the light output angle area of the sector box 14 when the flying spot scanning device 1 includes only one ray source 11 (that is, when the flying spot scanning device 1 adopts a single light source design), the corresponding preset angle is 120°, then the light output angles of the two sector boxes 14 in this embodiment are both 60°.

[0083] Both sets of beam holes 15 are located on the rim of the flywheel 13. As the flywheel 13 rotates, each beam hole 15 in each set rotates through the beam-emitting angle region of its corresponding sector box 14, allowing X-rays to pass through and form a pencil beam. Furthermore, the two sets of beam holes 15 are spaced apart along the length of the inspection channel, corresponding one-to-one with the two radiation sources 11 along the length of the inspection channel. Each set of beam holes 15 includes multiple beam holes 15, and the beam holes 15 in the same set are evenly spaced and arranged on the same circumference. The number of beam holes 15 in each group of beam holes 15 is greater than the number of beam holes 15 when the flying spot scanning device 1 includes only one radiation source 11. Specifically, the number of beam holes 15 in each group of beam holes 15 is twice (i.e., n times) the number of beam holes 15 when the flying spot scanning device 1 includes only one radiation source 11. For example, if the number of beam holes 15 when the flying spot scanning device 1 includes only one radiation source 11 is 3, then in this embodiment, the number of beam holes 15 in each group of beam holes 15 is 6. Each beam hole 15 is circular.

[0084] Based on the above configuration, the inspection device constitutes a dual-ray source flying spot scanning device, and its two ray sources 11 are both pulse ray sources and share a set of flying spot devices 12 and backscatter detectors 21 .

[0085] During the work process, Figure 7 As shown, the two ray sources 11 of the inspection device emit beams in turn, and each ray source 11 evenly emits m beams (m exist Figure 7In the figure, m light beams uniformly emitted by one ray source 11 within the light-emitting angle of its corresponding sector box 14 are marked as 1-1, 1-2, ... 1-m, and m light beams uniformly emitted by another ray source 11 within the light-emitting angle of its corresponding sector box 14 are marked as 2-1, 2-2, ... 2-m). The backscatter detector 21 collects the reflected photon signals generated by the pencil beam emitted by each ray source 11 and incident on the object to be inspected in turn, and through data processing, the data of the same vertical plane of each ray source 11 within the light-emitting angle of its respective sector box 14 are pieced together.

[0086] Depend on Figure 6 and Figure 7 It can be seen that compared with the single-ray source flying spot scanning device in the related art, the dual-ray source flying spot scanning device of this embodiment can increase the scanning speed and reduce the beam column spacing (making the column spacing become 1 / 2 of the original) without increasing the flywheel rotation speed, while keeping the overall light output angle of the flying spot device 12 unchanged (120° in the case of a single light source and still 120° in the case of multiple light sources) and without reducing the scanning range, thereby reducing the risk of undersampling, lowering the technical difficulty and reducing the safety risk.

[0087] Moreover, since both ray sources 11 are pulsed ray sources, the two ray sources 11 can be conveniently controlled to emit beams in sequence, so that the rays emitted by the two ray sources 11 are emitted in sequence from the flying spot device 12, reducing mutual interference between the photons emitted by the two ray sources 11.

[0088] At the same time, since the two ray sources 11 share a set of flying spot devices 12 and backscatter detectors 21, the structure is simpler, the cost is lower, and less space is occupied.

[0089] It can be seen that the radiographic inspection system of this embodiment can safely and effectively reduce the undersampling risk in the flying spot scanning process based on a relatively simple structure and low cost.

[0090] Next, we will introduce Figure 8 The embodiment shown.

[0091] To simplify the description, only the following Figure 8 The embodiment shown is similar to the above Figure 4-Figure 7 The differences between the illustrated embodiments.

[0092] like Figure 8 As shown, this embodiment is similar to the above Figure 4-Figure 7 The main difference of the embodiment shown is that in this embodiment, the inspection device no longer includes only two radiation sources 11, but includes more radiation sources 11, that is, the inspection device includes at least three radiation sources 11, that is, the number n of radiation sources 11 in the inspection device is In this case, the light emission angle of the sector box 14 corresponding to each ray source 11 is 1 / n of that when a single ray source is used, and the number of beam holes 15 corresponding to each sector box 14 is n times that of a single ray source. During operation, each ray source 11 emits a beam in sequence. When the flywheel speed and the scanning speed (i.e., the relative movement speed between the object under inspection and the flying spot scanning device 1) are the same, the beam column spacing is 1 / n of the original. Therefore, the beam column spacing can be effectively reduced, thereby reducing the risk of missed scanning.

[0093] Next, we will introduce Figure 9 The embodiment shown.

[0094] To simplify the description, only the following Figure 9 The embodiment shown is similar to the above Figure 4-Figure 7 The differences between the illustrated embodiments.

[0095] like Figure 9 As shown, this embodiment is similar to the above Figure 4-Figure 7 The main difference between the illustrated embodiments is that the two groups of beam holes 15 are no longer arranged on the same flywheel 13, but are arranged on two different flywheels 13, and the two radiation sources 11 no longer share a set of backscatter detectors 21, but each uses a set of backscatter detectors 21. At this time, the inspection device no longer includes only one pair of backscatter detectors 21, but includes two pairs of backscatter detectors 21, and the flying spot device 12 of the inspection device no longer includes only one flywheel 13, but includes two flywheels 13.

[0096] The above description is merely an exemplary embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A flying spot scanning device (1), characterized in that: include: n ray sources (11), n ; and A flying spot device (12) comprises a flywheel (13), n sector boxes (14) and n groups of beam holes (15), wherein the n sector boxes (14) and the n groups of beam holes (15) correspond one-to-one to the n ray sources (11), the light emission angles of the n sector boxes (14) are all located within a preset angle region of the flywheel (13) and are staggered in the circumferential direction of the flywheel (13), the light emission angles of the n sector boxes (14) cover the entire preset angle region, the number of beam holes (15) in each group of beam holes (15) is equal to 360° / the light emission angle of the corresponding sector box (14), and the rays emitted by the n ray sources (11) are sequentially emitted from the flying spot device (12).

2. The flying spot scanning device (1) according to claim 1, characterized in that The light emission angles of the fan-shaped boxes (14) are the same or different.

3. The flying spot scanning device (1) according to claim 2, characterized in that The light output angle of each fan-shaped box (14) is 1 / n of the preset angle.

4. The flying spot scanning device (1) according to claim 1, characterized in that The n ray sources (11) are located on the same plane perpendicular to the relative movement direction of the object to be inspected and the flying spot scanning device (1); or, the n ray sources (11) are arranged in sequence along the relative movement direction of the object to be inspected and the flying spot scanning device (1).

5. The flying spot scanning device (1) according to claim 1, characterized in that The ray source (11) emits beams continuously or discontinuously.

6. The flying spot scanning device (1) according to claim 5, characterized in that The ray source (11) emits pulsed beams.

7. The flying spot scanning device (1) according to any one of claims 1 to 6, characterized in that: The n ray sources (11) emit beams in sequence.

8. The flying spot scanning device (1) according to any one of claims 1 to 6, characterized in that: The n groups of beam holes (15) are arranged on the same flywheel (13), or the n groups of beam holes (15) are arranged on different flywheels (13).

9. The flying spot scanning device (1) according to any one of claims 1 to 6, characterized in that: The n ray sources (11) are n X-ray machines, or the n ray sources (11) are n target points on the same X-ray machine.

10. The flying spot scanning device (1) according to any one of claims 1 to 6, characterized in that: Each of the ray sources (11) emits a plurality of beams within the light emission angle range of the corresponding fan-shaped box (14).

11. A radiographic inspection system comprising a detector (2), characterized in that: It also includes a flying spot scanning device (1) as claimed in any one of claims 1 to 10, wherein the flying spot scanning device (1) cooperates with the detector (2) to perform flying spot scanning on the object to be inspected.

12. The radiographic inspection system according to claim 11, wherein: The detector (2) includes a backscatter detector (21) and / or a transmission detector.

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