A passive millimeter-wave / terahertz human body security inspection system

Abstract

This invention provides a passive millimeter-wave / terahertz human body security inspection system, which solves the problem that existing systems are not conducive to directly detecting the side of the human body. It includes a millimeter-wave / terahertz security scanner for detecting the front or back of the person being inspected. A reflector is respectively installed on both outer sides of the area formed between the front side of the scanner's viewing window and the person being inspected, with the mirror surfaces of the two reflectors facing each other. The two reflectors can reflect the millimeter-wave / terahertz waves emitted from the side of the person being inspected into the field of view of the scanner. Therefore, the detector in the scanner can directly detect and collect the millimeter-wave / terahertz waves emitted from the side of the human body and achieve imaging detection of the side of the human body.

Description

Technical Field

[0001] This invention relates to the field of security inspection technology, and in particular to the field of passive terahertz security inspection technology, specifically a passive millimeter-wave / terahertz human body security inspection system. Background Technology

[0002] Passive millimeter-wave / terahertz human body security inspection systems utilize the terahertz imaging principle to detect and collect terahertz waves or millimeter waves of specific wavelengths naturally emitted by the human body for imaging and detection. Due to its advantages such as zero radiation, no stopping, non-contact, good privacy protection, high security inspection efficiency, good imaging effect, and ability to detect a wide variety of prohibited items, it has been gradually promoted and applied in places with large crowds, such as police checkpoints, subway stations, airports, train stations, docks, ports, and high-speed rail lines.

[0003] Since millimeter waves / terahertz waves cannot penetrate the human body, existing millimeter wave / terahertz security scanners can only detect individuals positioned within their field of view (see [link to image]). Figure 1 In practical applications, to achieve simultaneous detection of the front and back of the person being tested, a millimeter-wave / terahertz security scanner is typically placed in front of and behind the person as they move (see...). Figure 2 However, existing passive millimeter-wave / terahertz human body security inspection systems cannot detect the sides of the person being inspected. Therefore, they often need to be used in conjunction with metal detectors or X-ray detectors to conduct all-round inspections, which leads to low security inspection efficiency. Although theoretically, deploying corresponding millimeter-wave / terahertz security detectors on the sides of the person being inspected can also achieve side detection, this would greatly increase the inspection cost and require more stringent deployment site requirements, making it unsuitable for large-scale promotion and application. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a passive millimeter-wave / terahertz human body security inspection system, which solves the problem that existing systems are not conducive to directly detecting the sides of the human body.

[0005] The technical solution is a passive millimeter-wave / terahertz human body security inspection system, which includes a millimeter-wave / terahertz security inspection instrument for detecting the front or back of the person being tested. The system is characterized in that a reflector is respectively set on the two outer sides of the area formed between the front side of the window of the millimeter-wave / terahertz security inspection instrument and the person being tested, and the mirror surfaces of the two reflectors are arranged facing each other.

[0006] Furthermore, let point A be the center point of the viewing window of the millimeter-wave / terahertz security scanner. Let the ray extending from point A along the straight line directly in front of the center of the field of view of the millimeter-wave / terahertz security scanner be the center line. The two reflectors are symmetrically arranged about the center line.

[0007] Furthermore, the angle α formed between the line connecting the center points O1 and O2 of the two reflectors and the center line is less than half of the field of view of the millimeter-wave / terahertz security scanner.

[0008] Furthermore, taking the lines connecting the centers O1 and O2 of the two reflectors to point A as the incident rays O1A and O2A respectively, then the two outgoing rays satisfying the specular reflection theorem intersect the center line at point C. The distance between point A and point C should be within the imaging distance range of the millimeter-wave / terahertz security inspection instrument.

[0009] Furthermore, two millimeter-wave / terahertz security scanners are provided, with their viewing windows facing each other. A detection channel is formed in the area between the two millimeter-wave / terahertz security scanners. The reflectors are respectively installed on the front side of the viewing window of each millimeter-wave / terahertz security scanner and on the two outer sides of the detection channel.

[0010] The beneficial effects of this invention are as follows: Two mirrors with facing surfaces are respectively installed on both sides of the area formed between the window of the millimeter-wave / terahertz security scanner and the person being tested. These mirrors reflect the millimeter-wave / terahertz waves emitted from the side of the person being tested into the field of view of the security scanner. Thus, the detector in the security scanner can directly detect and collect the millimeter-wave / terahertz waves emitted from the side of the human body and achieve imaging detection of the side of the human body. Therefore, even with an increase in the number of millimeter-wave / terahertz security scanners, imaging detection of the side of the human body can be achieved, avoiding the need for traditional methods that require the use of metal detectors or X-ray detectors for comprehensive inspection. This ensures security inspection efficiency and accuracy. Furthermore, the system layout does not have stringent site requirements, making it easier for large-scale promotion and application. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of an existing human body detection system using a single millimeter-wave / terahertz security scanner.

[0012] Figure 2 This is a schematic diagram illustrating the current method of using two millimeter-wave / terahertz security scanners to detect human bodies.

[0013] Figure 3 This is a schematic diagram of the layout of a passive millimeter-wave / terahertz human body security inspection system according to the present invention;

[0014] Figure 4 This is a schematic diagram of another embodiment of the present invention.

[0015] Attached label: 10-millimeter wave / terahertz security scanner, 20-person being inspected, 30a-reflector, 30b-reflector, 40-centerline, 50-detection channel. Detailed Implementation

[0016] See Figure 3 This invention discloses a passive millimeter-wave / terahertz human body security inspection system, comprising a millimeter-wave / terahertz security scanner 10 for detecting the front or back of a person being inspected. Two reflectors, 30a and 30b respectively, are respectively arranged on the outer sides of the area formed between the front side of the viewing window of the millimeter-wave / terahertz security scanner 10 and the person being inspected. The mirror surfaces of the two reflectors 30a and 30b are arranged facing each other. The center point of the viewing window of the millimeter-wave / terahertz security scanner 10 is denoted as point A. A ray extending straight forward from point A along the center of the field of view of the millimeter-wave / terahertz security scanner is designated as the centerline 40. The reflectors 30a and 30b are symmetrically arranged about the centerline 40, that is, the center O1 of the mirror surface of reflector 30a and the center O2 of the mirror surface of reflector 30b are symmetrically arranged about the centerline 40. The connecting line should be perpendicular to the center line 40. Furthermore, the angle α formed between the line connecting the center points O1 and O2 of the two reflectors 30a and 30b and the center line 40 should be less than half the field of view of the millimeter-wave / terahertz security scanner. Simultaneously, taking the lines connecting the center points O1 and O2 of the two reflectors 30a and 30b to point A as the incident rays O1A and O2A, respectively, the two outgoing rays satisfying the specular reflection theorem intersect the center line at point C. The distance between point A and point C should be within the imaging distance range of the millimeter-wave / terahertz security scanner. This configuration ensures that the millimeter-wave / terahertz waves emitted from the side of the person being inspected are effectively reflected by the reflectors 30a and 30b on both sides and enter the millimeter-wave / terahertz security scanner 10, thereby ensuring the side imaging effect and guaranteeing the accuracy of the security check.

[0017] The present invention also provides another embodiment, which involves simultaneously setting up two millimeter-wave / terahertz security scanners, namely 10a and 10b, see [link to embodiment]. Figure 4The viewing windows of two millimeter-wave / terahertz security scanners 10a and 10b are set facing each other, forming a detection channel 50 between the two scanners. Reflectors 30a and 30b are respectively installed in front of the viewing window of each scanner and on both sides of the detection channel 50. When a person walks in the detection channel 50, the two scanners 10a and 10b image the front and back of the person, respectively. The two sets of reflectors on both sides of the detection channel 50 can reflect the millimeter-wave / terahertz waves emitted from the side of the person into the field of view of the scanner. Thus, the detector in the scanner can directly detect and collect the millimeter-wave / terahertz waves emitted from the side of the person and achieve imaging detection of the side of the person, further improving the detection accuracy.

[0018] The specific implementation of the present invention has been described in detail above, but the content is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made in accordance with the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A passive millimeter wave / terahertz human body security inspection system comprising a millimeter wave / terahertz security inspection device for detecting a front or back of a person under inspection, characterized in that: Two mirrors are respectively arranged outside the area formed between the front side of the window of the millimeter wave / terahertz security inspection apparatus and the person to be detected, and the mirror surfaces of the two mirrors are arranged opposite to each other; A center point A of the window of the millimeter wave / terahertz security inspection apparatus is recorded, a center line is formed by a ray extending along a straight line in front of the center of the field of view of the millimeter wave / terahertz security inspection apparatus and passing through the point A, and the two mirrors are arranged axially symmetrically with respect to the center line; The two outgoing light rays satisfying the mirror reflection theorem intersect the center line at a point C, and the distance between the point A and the point C should be within the imaging distance range of the millimeter wave / terahertz security inspection apparatus.

2. The passive millimeter wave / terahertz human body screening system according to claim 1, wherein: The millimeter wave / terahertz security inspection apparatus is provided with two units, the windows of the two units are arranged opposite to each other, a detection channel is formed between the two units, and a mirror is arranged outside the detection channel on the front side of the window of each unit.

Images