Property Inspection Device

Abstract

To provide a possessed object inspection device which can improve a detection ratio of a possessed object by reducing oversight of a small possessed object.SOLUTION: A possessed object inspection device is in a passive method which forms an image by receiving a black body radiation 2 radiated from an object and inspects a possessed object. The possessed object inspection device divides the black body radiation by a half mirror 4, collects the divided black body radiations by light collection mirrors 5, 8 in different sizes to input the black body radiations to corresponding detectors 11, 13, and performs synthesis processing on detected images in different pixel sizes to inspect a possessed object. By performing synthesis imaging processing in which the images in the different pixel sizes (resolutions) are combined, the device can reduce oversight of a small possessed object and improve a detection ratio of a dangerous object such as a cutter, a firearm and an explosive.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a passive possession inspection device that receives and images blackbody radiation (thermal noise) emitted from an object to inspect possessions. [Background technology]

[0002] The technology of receiving blackbody radiation emitted from an object and imaging it is used in astronomical observations, etc. Also, products that apply blackbody radiation images to body scanners for security purposes are known. For example, Patent Document 1 describes a passive type millimeter wave imaging device and an imaging image display device that capture an image of a subject by receiving thermal noise in the millimeter wave band emitted from the subject human body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-21954 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, passive type devices such as those described in Patent Document 1 have a trade-off problem between reception intensity and pixel size (resolution). That is, the intensity of the received blackbody radiation is proportional to the size of the polygon mirror and the light-collecting mirror, but the pixel size is also proportional to the size of the mirror, so there is a trade-off between reception intensity and resolution. Moreover, when scanning with a polygon mirror, the pixel size also changes depending on the vertical angle, so the reception intensity and resolution differ and the captured image becomes non-uniform.

[0005] This poses the problem that small items may be overlooked during baggage inspections, and the detection rate for items may be reduced.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a possession inspection device that can reduce the oversight of small possessions and improve the detection rate of possessions. [Means for solving the problem]

[0007] A personal belongings inspection device according to one embodiment of the present invention is a passive type personal belongings inspection device that receives blackbody radiation emitted from an object, images it, and inspects personal belongings, and is characterized in that the blackbody radiation is divided by a half mirror, and the divided blackbody radiation is focused by focusing mirrors of different sizes and input into corresponding detectors, and the detected images with different pixel sizes are synthesized and processed to inspect the personal belongings. Effect of the Invention

[0008] According to the possession inspection device of the present invention, images with different pixel sizes are received simultaneously through a half mirror, and these images with different pixel sizes are combined to perform a composite image processing, thereby reducing the oversight of small possessions and improving the possession detection rate. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a possession inspection device according to an embodiment of the present invention; [Diagram 2] 2 is a perspective view for explaining a configuration example in which the possession inspection device in FIG. 1 is of a walk-through type. FIG. [Diagram 3] FIG. 3 is a plan view of FIG. 2 seen from above. [Figure 4] 4 is a diagram showing an image captured when the possession inspection device shown in FIGS. 1 to 3 detects the intrusion of a human body. FIG. [Diagram 5] 4 is a flowchart for explaining the operation of the possession inspection device shown in FIGS. 1 to 3. [Figure 6] 6 is a flowchart for explaining the operation following FIG. 5. [Figure 7] FIG. 4 is a diagram for explaining a pixel arrangement of a first collector mirror. [Figure 8] 13 is a diagram for explaining a pixel arrangement of a second collector mirror. FIG. [Figure 9] 10 is a diagram for explaining a pixel arrangement in which a first collector mirror and a second collector mirror are combined. FIG. [Figure 10] 4A to 4C are diagrams showing a detected image and a composite image in the possession inspection device shown in FIGS. 1 to 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 shows a schematic configuration of a possession inspection device according to an embodiment of the present invention. This possession inspection device detects blackbody radiation 2 emitted from a human body 1, which is a subject, by scanning it with a polygon mirror 3 rotating at high speed. The blackbody radiation 2 reflected by the polygon mirror 3 is reflected and transmitted by a half mirror 4. The transmitted blackbody radiation 2 is guided by a first collecting mirror 5 to a first antenna (horn antenna) 6 and received there. Meanwhile, the reflected blackbody radiation 2 is guided via a mirror (third mirror) 7 and a second collecting mirror 8 to a second antenna (horn antenna) 9 and received there.

[0011] The first collector mirror 5 and the second collector mirror 8 are different in size, and for example, the dimensional ratio between the first collector mirror 5 and the second collector mirror 8 is two times (area ratio is four times) so that the pixel size difference is about two times. Since the resolution is determined by the size of the collector mirror, the reception intensity of the blackbody radiation 2 received by the first antenna 6 is stronger than that of the blackbody radiation 2 received by the second antenna 9, but the resolution is lower. In contrast, the reception intensity of the blackbody radiation 2 received by the second antenna 9 is weaker than that of the blackbody radiation 2 received by the first antenna 6, but the resolution is higher.

[0012] The rotation speed of the polygon mirror 3 is determined according to the pixel density of the mirror 7. Furthermore, the distribution ratio of the half mirror 4 is not limited to 5:5, but is determined in consideration of the area ratio of the first and second collector mirrors 5 and 8, and is set to be the same as the area ratio of the first and second collector mirrors 5 and 8, for example.

[0013] The blackbody radiation 2 received by the first antenna 6 is amplified by the amplifier 10, and then input to the detector 11 for detection. Similarly, the blackbody radiation 2 received by the second antenna 9 is amplified by the amplifier 12, and then input to the detector 13 for detection. The detection results by these detectors 11 and 13 are input to a processing unit 14, which synthesizes images with different pixel sizes. Based on the results of this synthesis process, when the processing unit 14 detects a dangerous object such as a blade, a firearm, or an explosive, it notifies a host device of the processing result.

[0014] Alternatively, the composite processed image is displayed on the display device 15, and when an inspector detects a dangerous object such as a knife, firearm, or explosive from the processing results or the displayed image, an alarm device 16 or the like is activated to alert those in the vicinity.

[0015] The image sampling rate in the processing unit 14 should be adjusted to the specifications for image synthesis combining each pixel. Also, the resolution can be improved by performing the image processing for each mirror (first and second collecting mirrors 5 and 8). In addition, the detection accuracy can be improved by using the synthesized image combining the pixels acquired by each mirror for judgment.

[0016] Fig. 2 shows an example of the configuration of the possession inspection device in Fig. 1 when it is configured as a walk-through type. Fig. 3 is a plan view of Fig. 2 as seen from above. Sensor units 21-1 to 21-4 are arranged on the left and right in front of and the left and right in the rear of a passage 20 indicated by an arrow in Figs. 2 and 3, respectively, to detect blackbody radiation 2 from a human body 1 walking along the passage 20 in the direction of the arrow, and to inspect possessions based on the detected blackbody radiation 2. These sensor units 21-1 to 21-4 are composed of upper units 21-1a to 21-4a and lower units 21-1b to 21-4b, respectively.

[0017] Sensor unit 21-1 arranged on the left front side of human body 1 detects the left half of the front side of human body 1 when human body 1 is positioned between sensor units 21-1 to 21-4, and sensor unit 21-2 arranged on the right front side of human body 1 detects the right half of the front side of human body 1. On the other hand, sensor unit 21-3 arranged on the left rear side of human body 1 detects the left half of the back side of human body 1 when human body 1 is positioned between sensor units 21-1 to 21-4, and sensor unit 21-4 arranged on the right rear side of human body 1 detects the left half of the back side of human body 1. Then, the blackbody radiation 2 detected by the above-mentioned sensor units 21-1 to 21-4 is processed into a composite image, and possessions are inspected.

[0018] 4 shows an image when the entry of a human body 1 is detected by the possession inspection device of Fig. 1 to Fig. 3, and is an image of vertical line scanning by two upper and lower units. The left front half of the image is captured by sensor unit 21-1 (upper sensor 21-1a and lower sensor 21-1b), and the right front half of the image is captured by sensor unit 21-2 (upper sensor 21-2a and lower sensor 21-2b). Similarly, on the rear side (not shown), the left rear half of the image is captured by sensor unit 21-3 (upper sensor 21-3a and lower sensor 21-3b), and the right rear half of the image is captured by sensor unit 21-4 (upper sensor 21-4a and lower sensor 21-4b).

[0019] In FIG. 4(a), the detection ranges of sensor units 21-1 and 21-2 are indicated by dashed lines, and the upper and lower parts of these detection ranges are detected by upper units 21-1a and 21-2a and lower units 21-1b and 21-2b.

[0020] In Fig. 4(b), the resolution of the image in Fig. 4(a) is represented by circles (indicated by dashed lines) 22 with different diameters in the vertical direction, with smaller diameter circles having higher resolution and larger diameter circles having lower resolution. When the human body 1 faces forward, the blackbody radiation 2 is incident on the polygon mirror 3 at an angle of 45° in each of the sensor units 21-1a, 21-2a, 21-1b, and 21-2b, so that the size of the circle 22 becomes smaller (the resolution becomes higher), and when the angle becomes steeper, the size of the circle 22 becomes larger (the resolution becomes lower). Therefore, the resolution of the center portion of each of the sensor units 21-1a, 21-2a, 21-1b, and 21-2b becomes higher and the resolution of both ends becomes lower.

[0021] 5 and 6 are flow charts for explaining the operation of the possession inspection device shown in Fig. 1 to Fig. 3. When a person passes between the sensor units 21-3 and 21-4, the intrusion of the human body 1 is detected (step S1), and the polygon mirror 3 is rotated (step S2). In steps S3 to S8, the mirror angle of the polygon mirror 3 is set sequentially from the upper limit to the lower limit, and the detection level of the first collecting mirror 5 (large mirror) and the detection level of the second collecting mirror 8 (small mirror) are obtained.

[0022] That is, in step S3, the mirror angle of the polygon mirror 3 is set to the upper limit, and the blackbody radiation 2 collected by the first collector mirror 5 is detected by the detector 11 and acquired by the processing unit 14, while the blackbody radiation 2 collected by the second collector mirror 8 is detected by the detector 13 and acquired by the processing unit 14. In step S4, the mirror angle of the polygon mirror 3 is set to "upper limit -1", and the blackbody radiation 2 collected by the first collector mirror 5 is detected by the detector 11 and acquired by the processing unit 14, while the blackbody radiation 2 collected by the second collector mirror 8 is detected by the detector 13 and acquired by the processing unit 14. In step S5, the mirror angle of the polygon mirror 3 is set to "upper limit -2", and the blackbody radiation 2 collected by the first collector mirror 5 is detected by the detector 11 and acquired by the processing unit 14, while the blackbody radiation 2 collected by the second collector mirror 8 is detected by the detector 13 and acquired by the processing unit 14.

[0023] Thereafter, the mirror angle of the polygon mirror 3 is similarly sequentially decreased from the upper limit, and the blackbody radiation 2 collected by the first collector mirror 5 is detected by the detector 11 and acquired by the processing unit 14, while the blackbody radiation 2 collected by the second collector mirror 8 is detected by the detector 13 and acquired by the processing unit 14 (step S6). In step S7, the mirror angle of the polygon mirror 3 is set to "lower limit - 1", and the blackbody radiation 2 collected by the first collector mirror 5 is detected by the detector 11 and acquired by the processing unit 14, while the blackbody radiation 2 collected by the second collector mirror 8 is detected by the detector 13 and acquired by the processing unit 14. Furthermore, in step S8, the mirror angle of the polygon mirror 3 is set to the “lower limit”, the blackbody radiation 2 collected by the first collector mirror 5 is detected by the detector 11 and acquired by the processing unit 14, and the blackbody radiation 2 collected by the second collector mirror 8 is detected by the detector 13 and acquired by the processing unit 14.

[0024] In the next step S9, the detection results from the upper limit to the lower limit are stored in the current time sequence of the image array of the first collector mirror 5. The image array of the first collector mirror 5 stored in this step S9 is shown in Fig. 7. The processing unit 14 stores the "current time t", "t-1" a predetermined time ago, "t-2" a further predetermined time ago, ..., and stores detection results obtained thereafter at "t+1" a predetermined time after the "current time t", "t+2" a further predetermined time after that, ...

[0025] At the "current time", images from the "upper limit" position of the large-sized first collector mirror 5 to the positions of "upper limit-1", "upper limit-2", "upper limit-3", "upper limit-4", ..., "lower limit-4", "lower limit-3", "lower limit-2", "lower limit-1", and "lower limit" are stored. At the time "t-1", images from the "upper limit" position of the first collector mirror 5 to the positions of "upper limit-1", "upper limit-2", "upper limit-3", "upper limit-4", ..., "lower limit-4", "lower limit-3", "lower limit-2", "lower limit-1", and "lower limit" are stored. At the time "t-2", images from the "upper limit" position of the first collector mirror 5 to the positions of "upper limit-1", "upper limit-2", "upper limit-3", "upper limit-4", ..., "lower limit-4", "lower limit-3", "lower limit-2", "lower limit-1", and "lower limit" are stored.

[0026] In step S10, the detection levels from the upper limit to the lower limit are similarly stored in the current time sequence of the image array of the second collector mirror 8. The image array of the second collector mirror 8 stored in step S10 is shown in Fig. 8. The processing unit 14 stores "t-1", a predetermined time before the "current time t", "t-2", a further predetermined time before that, ..., and stores detection results obtained thereafter in "t+1", a predetermined time after the "current time t", "t+2", a further predetermined time after that, ....

[0027] At the "current time", images from the "upper limit" position of the second collector mirror 8, which is smaller in size, to the positions "upper limit-1", "upper limit-2", "upper limit-3", "upper limit-4", ..., "lower limit-4", "lower limit-3", "lower limit-2", "lower limit-1", and "lower limit" are stored. At the time "t-1", images from the "upper limit" position of the second collector mirror 8 to the positions "upper limit-1", "upper limit-2", "upper limit-3", "upper limit-4", ..., "lower limit-4", "lower limit-3", "lower limit-2", "lower limit-1", and "lower limit" are stored. At the time "t-2", images from the "upper limit" position of the second collector mirror 8 to the positions "upper limit-1", "upper limit-2", "upper limit-3", "upper limit-4", ..., "lower limit-4", "lower limit-3", "lower limit-2", "lower limit-1", and "lower limit" are stored.

[0028] Thereafter, the detection levels of the second collector mirror 8 in the upper and lower parts and the first collector mirror 5 in the central part are stored in the current time column of the image array (step S11). The image array of the second collector mirror 8 stored in step S11 is shown in Fig. 9. The processing unit 14 stores "current time t", "t-1" a predetermined time ago, "t-2" a further predetermined time ago, ..., and stores detection results acquired thereafter at "t+1" a predetermined time after the "current time t", "t+2" a further predetermined time after, ....

[0029] At "current time", images from the "upper limit" position of the second collector mirror 8 to "upper limit -1", "upper limit -2", "upper limit -3", ... positions are stored. At the positions of "center +2", "center +1", "center", "center -1", and "center -2", images of the first collector mirror 5 are stored. At the positions of "lower limit -3", "lower limit -2", "lower limit -1", and "lower limit", images of the second collector mirror 8 are stored.

[0030] Furthermore, at time "t-1", images of the second collecting mirror 8 are stored at the positions "upper limit -1", "upper limit -2", "upper limit -3", ..., images of the first collecting mirror 5 are stored at the positions "center +2", "center +1", "center", "center -1", and "center -2", and images of the second collecting mirror 8 are stored at the positions "lower limit -3", "lower limit -2", "lower limit -1", and "lower limit".

[0031] Furthermore, at time "t-2", images of the second collecting mirror 8 are stored at positions "upper limit -1", "upper limit -2", "upper limit -3", ..., images of the first collecting mirror 5 are stored at positions "center +2", "center +1", "center", "center -1", and "center -2", and images of the second collecting mirror 8 are stored at positions "lower limit -3", "lower limit -2", "lower limit -1", and "lower limit".

[0032] Next, it is determined whether or not a person has passed between sensor units 21-1 and 21-2 (step S12), and if the advancement of human body 1 is detected, image processing (edge ​​detection), determination processing (presence or absence of possession), notification of the result to a higher-level device, and stopping of the polygon mirror are performed (step S13). The image processing may involve, for example, edge extraction using the intensity difference of the image, and rule-based processing to detect the presence or absence of the contour (edge) of the belongings present within the contour (edge) of the human body. Alternatively, the image may be processed using AI (deep learning, machine learning) to determine the presence or absence of belongings, and the type (e.g., a knife) of the belongings based on their characteristics. Furthermore, a combination of these processes may also be used. On the other hand, if the advancement of the human body 1 is not detected in step S12, the process returns to step S3 and the operations up to step S12 are repeated.

[0033] FIG. 10 shows an image of the detection output in the possession inspection device shown in FIG. 1 to FIG. 3. FIG. 10(a) is an image based on the pixels of the first collector mirror 5, and FIG. 10(b) is an image based on the pixels of the second collector mirror 8. FIG. 10(c) shows a composite image of FIG. 10(a) and (b). By combining the image of the center part of the first collector mirror 5 and the pixels of the upper and lower parts of the second collector mirror 8, an image is obtained that combines an image 23b based on the pixels of the second collector mirror 8, an image 23a based on the pixels of the first collector mirror 5, and an image 23c based on the pixels of the second collector mirror 8, as shown in FIG. 10(c). As a result, an image is obtained in which pixels of relatively similar sizes (resolutions) are arranged.

[0034] As described above, by combining the first collector mirror 5, which has low resolution but strong reception intensity of the blackbody radiation 2, with the second collector mirror 8, which has weak reception intensity but high resolution, it is possible to simultaneously capture a low-resolution image with strong intensity of the blackbody radiation 2 and an image with weak intensity but high resolution. By combining these images, it is possible to synthesize an image with a relatively uniform pixel size. This results in an image of the blackbody radiation 2 with uniform intensity, which also leads to improved resolution.

[0035] According to the present invention, blackbody radiation is reflected by a polygon mirror, and then the reflected radiation passes through a half mirror to form a receiving system with different sized collecting mirrors, thereby obtaining images with different pixel sizes. By performing a composite image processing that combines images with different pixel sizes (resolutions), it is possible to reduce overlooking small possessions and improve the detection rate of dangerous objects such as knives, firearms, and explosives. Moreover, the number of parts can be reduced compared to providing a polygon mirror for each pixel size, which also leads to cost reduction.

[0036] The configurations and operation procedures described in the above embodiments are merely schematic illustrations to enable the present invention to be understood and practiced. Therefore, the present invention is not limited to the described embodiments, and may be modified in various forms without departing from the scope of the technical ideas set forth in the claims.

[0037] For example, the parts to be synthesized may be changed depending on the position or height of the person who is the subject. In other words, the detection rate of dangerous objects can be improved by increasing the resolution or reception strength of parts that are likely to conceal dangerous objects. [Explanation of symbols]

[0038] Reference Signs List 1...human body, 2...blackbody radiation, 3...polygon mirror, 4...half mirror, 5...first collecting mirror, 6...first antenna, 7...mirror (third mirror), 8...second collecting mirror, 9...second antenna, 10...amplifier, 11...detector, 12...amplifier, 13...detector, 14...processing unit, 20...passage, 21-1 to 21-4...sensor units, 21-1a to 21-4a...upper units, 21-1b to 21-4b...lower units, 22...circle (resolution), 23a, 23b, 23c...images

Claims

1. A passive-type possession inspection device that receives and images blackbody radiation emitted from an object and inspects possessions, This possession inspection device is characterized in that the blackbody radiation is divided by a half mirror, the divided blackbody radiation is collected by collecting mirrors of different sizes and input to corresponding detectors, and the detected images with different pixel sizes are synthesized and processed to inspect the possessions.

2. 2. The possession inspection device according to claim 1, wherein the blackbody radiation is scanned by a polygon mirror and directed to the half mirror.

3. The possession inspection device described in claim 2, further comprising a first collecting mirror to which blackbody radiation that has passed through the half mirror is input, and a second collecting mirror to which blackbody radiation that has been reflected by the half mirror is input, and the first collecting mirror and the second collecting mirror have different sizes.

4. 4. The possession inspection device according to claim 3, further comprising a third mirror that guides the blackbody radiation reflected by the half mirror to the second collecting mirror.

5. 5. The possession inspection device according to claim 4, wherein the rotation speed of the polygon mirror is set in accordance with the pixel density of the third mirror.

Images