CT (Computed Tomography) security check device

Abstract

The utility model discloses a CT security check device, and belongs to the technical field of CT imaging. According to the utility model, the problem that the application range of the traditional CT equipment in the security check field is limited in the prior art is solved. The device comprises a radiation source, a detector assembly and a support frame. The support frame forms a scanning channel through which a detected object can pass; the detector assembly comprises a plurality of detector crystals which are continuously arranged, the plurality of detector crystals are arranged along a basic line, the basic line is a connecting line formed by sequentially connecting a line segment BD, an inferior arc DE and a line segment EC, and the line segment BD and the line segment EC are line segments on a maximum inscribed square with the rotation center as the circle center and the distance between the radiation source and the rotation center as the radius circle. The arc DE is an arc on the maximum inscribed circle of the maximum inscribed square, the line segment BD and the line segment EC are tangent to the arc DE, and the maximum inscribed circle coincides with the cross section circle of the scanning channel. Under the condition that an original scanning channel is not changed and the occupied area of the device is not increased, the application range of the CT device in the security check field is expanded.

Description

Technical Field

[0001] The utility model relates to the technical field of CT imaging, in particular to a CT security inspection device. Background Art

[0002] Among X-ray-based explosive inspection technologies, X-ray computed tomography imaging technology (referred to as "CT technology") is highly valued in the field of security inspection due to its unique advantages in precise inspection.

[0003] Based on the accuracy of CT equipment, CT equipment is used to replace the existing conventional security inspection machine to improve the accuracy of dangerous objects in luggage. Without changing the original scanning channel, the installation of CT equipment has the following problems:

[0004] 1. When the detectors are arranged continuously on the same circle with the radiation source target as the center, the distance between the radiation source and each detector is the same, and the spatial resolution of the center and edge of the same tomographic image is similar. However, the size of the traditional CT equipment is limited by the size of the original scanning channel. When the original scanning channel is not changed, compared with conventional security inspection machines, the installed CT equipment is wider and occupies a larger area, resulting in a reduction in the application scope of traditional CT equipment in the security inspection field.

[0005] 2. When the detectors are arranged continuously on the same circle with the center of the original scanning channel as the center, the radiation source and the detector are set opposite to each other, and the distance between the radiation source and the edge detector is very different from the distance between the radiation source and the center detector, resulting in a large difference in the spatial resolution between the center and the edge of the same tomographic image, making it impossible to achieve accurate scanning. Although the problem of spatial resolution difference can be solved by adding subsequent algorithms, it leads to increased workload and cost, thereby limiting the application scope of traditional CT equipment in the security inspection field. Utility Model Content

[0006] In view of the above analysis, the utility model aims to provide a CT security inspection device to solve the problem that the application scope of traditional CT equipment in the security inspection field is limited due to the huge difference between the distance between the radiation source and the edge detector and the distance between the radiation source and the center detector, the large footprint and high cost of the CT equipment after installation, which exists in the process of replacing conventional security inspection machines.

[0007] The purpose of this utility model is mainly achieved through the following technical solutions:

[0008] The utility model provides a CT security inspection device, comprising a ray source, a detector assembly and a supporting frame;

[0009] The support frame forms a scanning channel through which the object to be detected can pass;

[0010] The rotation center of the ray source when rotating around the scanning channel coincides with the central axis of the scanning channel;

[0011] A circle with the rotation center as the center and the distance between the ray source and the rotation center as the radius is set as the first circle;

[0012] The largest inscribed square of the first circle is set to be the first square, the inscribed points of the first square and the first circle are point A, point B, point C and point H, line segment AH>line segment AB, and line segment AB=line segment AC;

[0013] Set the largest inscribed circle of the first square to be the second circle, the inscribed points of the first square and the second circle to be points D, E, F and G, line segment AD = line segment AE and line segment AD > line segment AB;

[0014] Set the line connecting line segment BD, minor arc DE and line segment EC in sequence as the base line;

[0015] The cross-sectional shape of the scanning channel is a circle, and the circle coincides with the second circle;

[0016] The ray source is set at point A and is arranged opposite to the detector assembly;

[0017] The detector assembly includes a plurality of detector crystals arranged in series, wherein the plurality of detector crystals are arranged along a base line and are located between point B and point C.

[0018] Furthermore, the opening angle of the ray source is greater than or equal to 90°.

[0019] Furthermore, when the number of detector assemblies is an even number, the detector assemblies are symmetrically arranged with the base line as the axis of symmetry.

[0020] Furthermore, the number of detector components is an odd number greater than or equal to 3.

[0021] Furthermore, a line connecting a midpoint of the ray receiving surface of the detector crystal and the ray source is perpendicular to the ray receiving surface.

[0022] Furthermore, the shape of the rays emitted by the ray source is a fan-shaped beam.

[0023] Furthermore, the shape of the rays emitted by the ray source is a cone beam.

[0024] Furthermore, a rotating mechanism is also included.

[0025] Furthermore, the ray source and the detector assembly are fixedly connected to the rotating mechanism.

[0026] Furthermore, the focus of the ray source coincides with point A.

[0027] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0028] 1. The CT security inspection device of the utility model arranges the detector crystals arranged continuously on the detector assembly along the arc of the scanning channel, and also arranges them along two symmetrically arranged line segments tangent to and connected to the arc, so as to reduce the difference between the distance between the radiation source and the edge detector crystals and the distance between the radiation source and the center detector crystals, thereby reducing the difference in spatial resolution between the center and the edge of the same tomographic image obtained, and finally improving the inspection accuracy of the CT equipment without changing the original scanning channel and increasing the floor space of the device, and expanding the application scope of the CT device in the field of security inspection.

[0029] 2. In the CT security inspection device of the present invention, the distances between the ray source and each detector are nearly equal, which reduces the workload of subsequent algorithms and reduces costs.

[0030] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by implementing the present invention. The purpose and other advantages of the present invention can be achieved and obtained through the contents particularly pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components.

[0032] Figure 1 This is a structural schematic diagram of a CT security inspection device of the utility model;

[0033] Figure 2 for Figure 1 A schematic diagram of the structure after the ray source, detector assembly and rotating mechanism are connected;

[0034] Figure 3 is a schematic diagram of the structure of the detector assembly;

[0035] Figure 4 for Figure 1 Schematic diagram of the arrangement of the medium-ray source and detector components;

[0036] Figure 5 A schematic diagram of the spatial positions of the detector components and the base line when the detector components are arranged in a group;

[0037] Figure 6 is a schematic diagram of the spatial positions of the two sets of detector assemblies and the base line when two sets of detector assemblies are provided;

[0038] Figure 7is a schematic diagram of the spatial positions of three groups of detector assemblies and a base line when three groups of detector assemblies are provided;

[0039] Reference numerals:

[0040] 100-ray source, 200-detector assembly, 300-rotating mechanism, 400-base, 500-conveyor belt, 600-conveyor belt bracket;

[0041] 201-detector crystal, 202-fixed base;

[0042] a-rotation center, b-first circle, c-first square, d-second circle, e-base line. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0044] Example 1

[0045] A specific embodiment of the utility model is as follows Figure 1 and Figure 4 As shown, a CT security inspection device is disclosed, including a ray source 100, a detector assembly 200 and a support frame; the support frame forms a scanning channel through which the detected object can pass; the rotation center of the ray source 100 when rotating around the scanning channel coincides with the central axis of the scanning channel; a circle with the rotation center as the center and the distance between the ray source 100 and the rotation center as the radius is set as a first circle b; the largest inscribed square of the first circle b is set as a first square c, the inscribed points of the first square c and the first circle b are point A, point B, point C and point H, line segment AH>line segment AB, and line segment AB=line segment AC; The maximum inscribed circle of the first square c is set as the second circle d, the inscribed points of the first square c and the second circle d are point D, point E, point F and point G, line segment AD = line segment AE and line segment AD > line segment AB; the line connecting line segment BD, minor arc DE and line segment EC in sequence is set as the base line e; the cross-sectional shape of the scanning channel is a circle, and the circle coincides with the second circle d; the ray source 100 is set at point A and is arranged opposite to the detector assembly 200; each detector assembly 200 includes a plurality of detector crystals arranged in succession, and the plurality of detector crystals are arranged along the base line e and are located between point B and point C.

[0046] In this embodiment, the CT security inspection device arranges the detector crystals arranged continuously on the detector assembly along the arc of the scanning channel, and also arranges them along two symmetrical straight lines tangent to the arc, so as to reduce the difference in distance between the radiation source and the edge detector crystals and the distance between the radiation source and the center detector crystal, thereby reducing the difference in spatial resolution between the center and the edge of the same tomographic image obtained, and ultimately achieving improvement in the inspection accuracy of the CT equipment without changing the original scanning channel and increasing the footprint of the device, thereby expanding the application scope of the CT device in the security inspection field.

[0047] In this embodiment, without changing the original scanning channel or increasing the floor space of the device, the difference between the distance between the ray source and the edge detector crystal and the distance between the ray source and the center detector crystal is reduced, that is, the spacing between the ray source and each detector in the CT security inspection device of this embodiment is almost equal, which reduces the difference in the P value of the ray received by the edge detector crystal and the center detector crystal, reduces the workload of the subsequent algorithm, and reduces the cost.

[0048] In this embodiment, the detector crystals in the CT security inspection device are arranged continuously and use the same control board and acquisition module, which facilitates the rapid scanning of the CT security inspection device. At the same time, because the same control board and acquisition module are used, the overall cost of the CT security inspection device is reduced.

[0049] In this embodiment, the detector crystals are of the same specifications, which reduces the processing cost and the installation and maintenance cost of the detector crystals.

[0050] Furthermore, in this embodiment, the opening angle of the ray source 100 is greater than or equal to 90°, so as to ensure that the ray beam emitted by the ray source 100 can cover the ray receiving surfaces of all detector crystals on the detector assembly 200. At the same time, because the opening angle of the ray source 100 is greater than or equal to 90°, the difficulty of developing the ray source is reduced, thereby reducing the cost.

[0051] In this embodiment, the focus of the radiation source 100 coincides with point A, so that the distances between the focus of the radiation source and the radiation receiving surfaces on each detector crystal are closer to being equal.

[0052] Further, the detector assembly 200 is provided in at least one group.

[0053] In this embodiment, when the detector assembly 200 is provided in a group, as shown in FIG. Figure 5 As shown, the center line of the multiple detector crystals on each detector assembly 200 after being arranged continuously coincides with the base line e. At this time, in order to save costs and avoid waste of resources, the shape of the ray beam emitted by the ray source 100 is set to be a fan beam.

[0054] In this embodiment, when the number of detector assemblies 200 is even, the detector assemblies 200 are symmetrically arranged along the direction of the central axis of the scanning channel with the base line e as the symmetry axis, and the detector crystals on the detector assemblies 200 are arranged along the base line e and located between point B and point C. For example, when two groups of detector assemblies 200 are provided, they are a first detector assembly and a second detector assembly with the same structure, such as Figure 6 As shown, the first detector assembly and the second detector assembly are symmetrically arranged along the direction of the central axis of the scanning channel with the base line e as the center line. Considering that the rays emitted by the ray source 100 can cover all the detector crystals on the two detector assemblies, the shape of the ray beam emitted by the ray source 100 is set to be a cone beam.

[0055] In this embodiment, when the number of detector components 200 is an odd number greater than or equal to 3; the multiple detector crystals arranged continuously on one of the detector components are arranged along the base line e and are located between point B and point C; the remaining detector components are arranged symmetrically along the direction of the central axis of the scanning channel with the base line as the symmetry axis, and all the detector components are arranged side by side. For example, when the detector components 200 are arranged in three groups, they are the first detector component, the second detector component and the third detector component with the same structure, such as Figure 7 As shown, multiple detector crystals on the first detector assembly are arranged along the base line and located between point B and point C, and the second detector assembly and the third detector assembly are symmetrically arranged along the direction of the central axis of the scanning channel with the base line e as the symmetry axis. Considering that the rays emitted by the ray source 100 can cover all the detector crystals on the three detector assemblies 200, the shape of the ray beam emitted by the ray source 100 is set to be a cone beam.

[0056] Furthermore, the line connecting the midpoint of the ray receiving surface of the detector crystal and the ray source 100 is perpendicular to the ray receiving surface, so as to ensure that the rays emitted by the ray source 100 can vertically enter each detector crystal after penetrating the object to be detected, so that the distance between the ray source 100 and each detector crystal is as similar as possible, thereby ensuring the spatial resolution of the image.

[0057] Furthermore, the CT security inspection device of this embodiment further includes a rotating mechanism 300, such as Figure 1 and Figure 2 As shown, the radiation source 100 and the detector assembly 200 are fixedly connected to the rotating mechanism 300.

[0058] In this embodiment, considering the fixing of the rotating mechanism 300, as shown in FIG. Figure 1 As shown, the CT security inspection device of this embodiment also includes a base 400.

[0059] Furthermore, if Figure 3As shown, the detector assembly 200 includes a detector crystal 201 and a fixed base 202, the fixed base 202 is fixed on the rotating mechanism 300, and the detector crystals 201 are continuously arranged on the fixed base 202, wherein, preferably, the shape of the fixed base 202 in the length direction is the same as the base line e.

[0060] Furthermore, the CT security inspection device of this embodiment further includes a conveying device 500 , which runs through the scanning channel and is used to transport the object to be inspected through the scanning area of ​​the radiation source 100 .

[0061] In this embodiment, a conveying device support frame 600 is used to support the conveying device 500 .

[0062] Furthermore, the CT security inspection device of this embodiment also includes a motion control device, a radiation source control device, a data acquisition control device and a main control computer; the motion control device is connected to the conveying device and the rotating mechanism respectively, and is used to control the movement speed and movement direction of the conveying device, and is also used to control the rotation of the rotating mechanism. The radiation source control device is connected to the radiation source 100, and is used to control the start-up of the radiation source 100 and the shape of the radiation emitted. The data acquisition control device is connected to the detector assembly 200, and is used to collect data from the detector assembly 200. The main control computer is used to receive and analyze the data collected by the data acquisition control device.

[0063] The above are only preferred specific implementation methods of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims

1. A CT security inspection device, characterized in that: It comprises a radiation source (100), a detector assembly (200) and a supporting frame; The support frame forms a scanning channel through which the detected object can pass; The rotation center of the ray source (100) when rotating around the scanning channel coincides with the central axis of the scanning channel; Setting a circle with the rotation center as the center and the distance between the ray source (100) and the rotation center as the radius as a first circle; The largest inscribed square of the first circle is set to be the first square, the inscribed points of the first square and the first circle are point A, point B, point C and point H, line segment AH>line segment AB, and line segment AB=line segment AC; The maximum inscribed circle of the first square is set to be the second circle, the inscribed points of the first square and the second circle are point D, point E, point F and point G, line segment AD=line segment AE and line segment AD>line segment AB; Set the line connecting line segment BD, minor arc DE and line segment EC in sequence as the base line; The cross-sectional shape of the scanning channel is a circle, and the circle coincides with the second circle; The ray source (100) is arranged at point A and is arranged opposite to the detector assembly (200); The detector assembly (200) comprises a plurality of detector crystals (201) arranged in series, wherein the plurality of detector crystals (201) are arranged along the base line and are located between point B and point C.

2. The CT security inspection device according to claim 1, characterized in that: The opening angle of the ray source (100) is greater than or equal to 90°.

3. The CT security inspection device according to claim 1, characterized in that: When the number of the detector assemblies (200) is an even number, the detector assemblies (200) are symmetrically arranged with the base line as the axis of symmetry.

4. The CT security inspection device according to claim 1, characterized in that: The number of the detector assemblies (200) is an odd number greater than or equal to 3.

5. The CT security inspection device according to claim 1, characterized in that: A line connecting the midpoint of the ray receiving surface of the detector crystal (201) and the ray source is perpendicular to the ray receiving surface.

6. The CT security inspection device according to claim 1, characterized in that: The shape of the rays emitted by the ray source (100) is a fan-shaped beam.

7. The CT security inspection device according to claim 1, characterized in that: The shape of the rays emitted by the ray source (100) is a cone beam.

8. The CT security inspection device according to claim 1, characterized in that: Also included is a rotating mechanism (300).

9. The CT security inspection device according to claim 8, characterized in that: The ray source (100) and the detector assembly (200) are fixedly connected to the rotating mechanism (300).

10. The CT security inspection device according to claim 1, characterized in that: The focus of the ray source (100) coincides with point A.

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