JP2004069576A - X-ray physical examination system for security - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray inspection apparatus for obtaining a clear X-ray image during travel, without damming the flow of people at a safety gate and without making them aware of the inspection apparatus. <P>SOLUTION: The X-ray physical examination system comprises an inspection passage 1 where people pass by singly; an X-ray photographic apparatus, consisting of an X-ray source 2 and an X-ray detector 3 that are arranged so that an X-ray transmission image can be obtained, when people 4 pass a specific position 5 in an inspection passage; and a speed sensor 9 for measuring the traveling speed of people to the position ahead of the specific photographing position 5, thus measuring the traveling speed of a subject 4 by the speed sensor 9, avoiding the intensity of the X-ray source 2 based on the traveling speed for reducing exposure and performing X-ray photographing, and detecting the object that the subject is wearing, based on an outputted image signal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a security gate installed at an entrance or exit of an airport or a building to prevent dangerous goods such as explosives, knives and firearms, drugs and the like from being brought into the cabin, and to prevent carry-in of prohibited goods that cannot be cleared. More particularly, the present invention relates to an X-ray inspection system that performs X-ray imaging while a person is moving.
[0002]
[Prior art]
Conventionally, in order to prevent hijacking and terrorism at departure airports, the contents of carry-on baggage are photographed with X-rays and inspected based on the shape of the stored items. Passengers are passed through gates equipped with metal detectors to detect large metal products worn on them, so that knives and firearms, which are weapons, are not brought into the plane.
On the other hand, at the arrival airport, suspicious persons are searched for suspicious objects by examining the contents of their carry-on luggage, interrogating, and performing physical examinations in order to prevent bringing drugs and other embargoed goods to the country.
However, depending on the mechanical device, it is not possible to detect non-metallic dangerous goods or small weapons worn by passengers. Neither can it detect drugs or the like hidden inside the body or soles.
[0003]
If there is a terrorist attack on a passenger aircraft, the damage will be enormous. There may be situations where it is necessary to prevent carry-on.
Conventionally, a suspicious individual has been subjected to a physical examination by X-ray photography using an X-ray device, and has banned items such as weapons and drugs worn on the body.
[0004]
As such an X-ray physical examination apparatus, there is a Compass Body Scanner (trade name) manufactured by MMC International Co. of the Netherlands. This product scans a one-dimensional sensor and superimposes it into a two-dimensional image while a subject moves horizontally while moving on a movable table that travels horizontally while irradiating a vertical slit-shaped X-ray beam. . The officer observes the combined plane image and notifies when an object is detected.
In addition, Security 1000 (trade name) manufactured by Rapiscan Security Products Co. of the United States scans the whole body with a pencil-shaped X-ray beam while standing a subject in front of a measurement surface, and scatters X light on the subject. The presence of an object hidden under clothes is detected by detecting the line.
[0005]
In these conventional X-ray physical examination devices, since a flow of a person is blocked and a specific test is performed, the test takes time and the flow is congested. In addition, the subject becomes in a psychological state as a suspect and has a feeling of resistance as if human rights were violated. In addition, since the subject is bothersomely guided to the inspection device, there is a margin for hiding or abandoning prohibited items or weapons at the opportunity.
[0006]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide an X-ray inspection that can obtain a clear X-ray image while moving without stopping the flow of people at the security gate and without being conscious of the inspection device. Is to provide a system.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the security X-ray physical examination system of the present invention is arranged so as to acquire an X-ray transmission image when a person passes through an examination passage through which a person passes one by one and a predetermined position of the examination passage. An X-ray imaging apparatus including a selected X-ray source and an X-ray detector, and a speed sensor for measuring a moving speed of a person at a position before a predetermined position used for imaging, and movement of a subject to be inspected by the speed sensor. Measuring the speed, adjusting the irradiation condition of the X-ray source based on the moving speed, performing X-ray imaging, and detecting an object worn by the subject based on the output image signal. .
[0008]
The X-ray physical examination system of the present invention allows passengers and immigrant to undergo a physical examination by X-ray transmission while passing through the gate. Since the inspection is completed during the inspection, the inspection can be performed efficiently and without causing any unpleasant feeling. In addition, since it is X-ray photography, it is possible to search for hidden prohibited items such as non-metallic weapons and drugs that do not respond to the metal detector.
[0009]
However, since it is required to avoid X-ray exposure as much as possible, it is preferable to suppress the irradiation dose of the X-ray source to a minimum size necessary for X-ray imaging. In the X-ray physical examination system of the present invention, the speed at which the subject passes through the gate can be measured, and the appropriate X-ray intensity can be adjusted for each subject. In order to obtain a blur-free image for those who move at high speed, it is necessary to use strong X-rays in a short time, but for those who pass slowly, instead of increasing the exposure time, the X-ray intensity must be increased. Can be set lower.
[0010]
The speed sensor illuminates from one side of the inspection passage, and on the other side, a large number of fiber ends are arranged in a straight line to detect the position of incident light, and a large number of photoelectric switches are arranged in a row. By using a sensor or an area sensor, the moving speed of the person can be calculated by measuring the distance that the tip of the shadow advances as the person moves. In addition, even if one image sensor is used, the moving speed of a person can be similarly calculated. Further, the moving speed of a person may be directly measured using a speed gun.
[0011]
Further, a body thickness sensor for measuring the thickness of the subject's body may be provided in the examination passage, and the irradiation condition of the X-ray source may be adjusted based on the measurement result. Fat people need to irradiate strong X-rays in order to obtain X-ray transmission images, but thin people and children do not need to irradiate strong X-rays. It is preferable to avoid applying unnecessary strong X-rays as much as possible.
The body thickness can be obtained from the shadow of the body and the width of the shadow. Therefore, like the speed sensor, the body thickness sensor illuminates from one side of the inspection passage, and a fiber sensor, photoelectric switch row, area sensor, etc. are arranged on the other side, or one image sensor is used. It can be composed of those arranged.
[0012]
Furthermore, a surveillance camera may be installed in the examination passage to acquire an image of the subject's face or whole body, and record it in the database in association with the X-ray image signal. It can be used to identify and arrange suspects if they do not know during an X-ray physical examination but later become suspicious.
A human sensor for detecting the presence of a subject at a predetermined position as an X-ray imaging place may be provided, and the X-ray imaging apparatus may be operated based on a detection signal of the human sensor to perform X-ray imaging. When the X-ray imaging is automated using such a sensor, the inspection efficiency is greatly improved, and the flow of the passing passengers and immigrant can be smoothly controlled.
[0013]
As a human sensor, a contact-type switch may be provided in a passage so that a passing person can operate it by hand or foot. A board interlocking with the switch may be laid at a position where a person on the aisle always steps on the switch, and the switch may be activated by stepping on the board, or an observer may operate the switch. Such a contact switch has an extremely simple structure and can be obtained at a low cost.
Further, a load switch for detecting a weight may be used. Even a simple foot switch can detect the presence of a person to be inspected. Also, using a device capable of measuring the weight, adjusting the X-ray generator based on the measured weight of the subject, setting the optimum X-ray intensity to obtain a clearer image Good.
Furthermore, the presence of a person can also be detected by a temperature sensor. Further, a contact sensor may be arranged on the floor of the passage so as to generate a detection signal when a person comes thereon.
Also, a sensor of a type that detects the presence or absence of a person by capturing a reflected beam using a light beam such as an ultrasonic wave or an infrared ray can be used.
[0014]
The X-ray source and the X-ray detector may be arranged on the sides of the examination passage, respectively, so that a straight line connecting the two passes through the X-ray imaging position and intersects at an angle in the traveling direction of the examination passage. Further, they may be arranged below the ceiling and the floor of the inspection passage, respectively.
By irradiating the subject's body obliquely with X-rays, X-ray exposure can be suppressed and a clear X-ray image can be obtained. It is preferable that the X-ray source and the X-ray detector are stored in a position that is invisible to the subject's eyes.
[0015]
The entrance of the inspection passage is provided with an entrance obstacle that blocks the passage of people, and a human sensor is provided to detect the presence of a person in the inspection passage.The entrance obstacle is detected only when the human sensor does not detect the presence of a person. You may comprise so that a person may enter a test | inspection passage by taking away an object. Since it is difficult to make a correct decision when a plurality of persons simultaneously hang on the examination apparatus, it is preferable to make sure that each person is always in the examination path at all times so that a reliable decision can be made. Note that a rotating bar, an opening / closing door, a rotating door, or the like can be used as the entrance obstacle.
[0016]
The X-ray detector may include a one-dimensional X-ray sensor to perform imaging by moving relative to an object, or a method to include a two-dimensional X-ray sensor to collectively image the object. It may be.
The one-dimensional X-ray sensor includes a combination of a scintillator and a photodiode, a semiconductor detector, an ion chamber, and the like. The two-dimensional X-ray sensor includes a flat panel detector, an imaging plate, an image intensifier, and the like.
[0017]
Equipped with an exit obstacle at the exit of the inspection passage and a door to the side of the detailed inspection site, if the inspection proves that no suspicious objects are being carried, the exit is automatically opened and the gate is passed If suspicious things are detected, they can be taken to another room for arrest or further scrutiny.
Note that a conveyor may be provided in the examination passage so that the subject is transported by the conveyor. When the conveyor is used, the subject passes through the position of the X-ray inspection apparatus at an appropriate speed, and thus can be sequentially subjected to the X-ray physical examination under the appropriately suppressed X-ray exposure.
In the X-ray physical examination system of the present invention, it is preferable to provide a door having an X-ray shielding ability formed of a material containing iron or lead at the entrance.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to examples.
FIG. 1 is a plan view showing a first embodiment of a security X-ray physical examination system according to the present invention, and FIG. 2 is a plan view showing a second embodiment.
[0019]
Embodiment 1
The first embodiment is an X-ray physical examination apparatus which is installed at an airport for inspecting passengers and immigrant, and has a two-dimensional X-ray sensor arranged in a straight path. A person is radiographed while walking through a passage.
An X-ray source 2 and an X-ray detector 3 are provided with an inspection passage 1 interposed therebetween. The subject 4 walks through the examination passage 1. An imaging position 5 is set in the middle of the examination passage 1, and the X-rays emitted from the X-ray source 2 pass through the subject 4 obliquely passing through the imaging position 5 from the X-ray detector 3. To form an X-ray transmission image. The output of the X-ray detector 3 is supplied to the X-ray inspection control device 6.
[0020]
When the X-ray detector 3 uses a two-dimensional X-ray sensor such as a flat panel detector, an imaging plate, and an image intensifier, the X-ray source 2 is configured as shown in FIG. A beam having a two-dimensional spread is used. The X-ray source 2 and the X-ray detector 3 are arranged so that the X-ray beam passes obliquely through the body of the subject. This is because X-ray exposure can be reduced as much as possible by irradiating in the direction in which the body thickness is as thin as possible.
[0021]
The X-ray inspection control device 6 controls the X-ray source 2 and the X-ray detector 3 in addition to processing and imaging the output of the X-ray detector 3.
The X-ray inspection control device 6 causes the image display device 7 to display an X-ray transmission image. In addition, foreign matter can be automatically detected by image processing using pattern recognition or the like, and the detection result can be displayed so as to be superimposed on the X-ray transmission image. The attendant can observe the X-ray transmission image displayed on the image display device 7 and refer to the automatic detection result to find clothes of the subject 4 and suspicious objects hidden in the body.
[0022]
In the X-ray physical examination apparatus of the present embodiment, a speed sensor 9 and a body thickness sensor 10 are installed before the imaging position 5, and a human sensor 8 is installed at the imaging position 5. Further, an entrance opening / closing door 11 may be provided at the entrance of the inspection passage 1. The entrance opening / closing door 11 is a door that is opened only when there is no person in the inspection passage 1 in order to perform inspection one by one. Further, the inspection passage 1 may be provided with a monitoring camera 12 for monitoring the subject 4 and taking pictures of the face and body.
[0023]
Further, an exit opening / closing door 13 is provided at an exit of the inspection passage 1, and a door 14 leading to a room where a detailed inspection is performed is provided on a side surface of the inspection passage 1 so as to be inconspicuous. If there is no problem as a result of the physical examination, the exit door 13 is opened, and the subject 4 can enter the gate. However, if any problems are found as a result of the examination, the exit door 13 is locked. Instead, the side door 14 opens to guide the subject 4 to the detailed inspection site, where the examiner will be inspected.
[0024]
The speed sensor 9 may measure the traveling speed of the shadow of the subject. For example, one side of the inspection passage 1 is illuminated with visible light, infrared light, or the like, and an optical sensor provided on the opposite side measures the traveling speed of the shadow. As the optical sensor, a fiber sensor that detects the position of incident light by arranging a large number of fiber ends in a straight line, a sensor in which a large number of photoelectric switches are arranged in a row, an area sensor, or the like can be used. Further, the moving speed of a person may be directly measured using a speed gun. Alternatively, one image sensor can be used to calculate the speed at which the person is traveling.
[0025]
Further, the body thickness sensor 10 measures the thickness of the human body, and may obtain the width of the silhouette at a certain moment, or, if the traveling speed is known, measures the transit time of the human body. May be. The detection unit can also be used as a body thickness sensor by diverting an optical sensor or an image sensor in the speed sensor and processing the measurement result so as to be suitable for thickness measurement. Of course, an independent detection unit may be installed and used as the body thickness sensor.
[0026]
The human sensor 8 has a contact type switch installed in the passage so that a passing person can operate it with his / her hand or foot. A plate interlocking with the switch is laid at a position where a person on the passage always steps on. The switch may be activated when depressed, or the switch may be operated by an observer. A human sensor constituted by a contact-type switch having such a simple structure can be manufactured at extremely low cost.
Further, a load switch for detecting a weight may be used. Even a simple foot switch can detect the presence of a person to be inspected. When using a device that can measure weight, adjust the X-ray generator based on the measured weight of the subject and set the optimal X-ray intensity to obtain a clearer image Can be.
[0027]
Further, the presence of a person can be detected by a temperature sensor using infrared rays or the like. Further, a contact sensor may be arranged on the floor of the passage so as to generate a detection signal when a person comes thereon.
Also, a sensor of a type that detects the presence or absence of a person by capturing a reflected beam using a light beam such as an ultrasonic wave or an infrared ray can be used.
[0028]
In the X-ray physical examination apparatus according to the present embodiment, when the subject 4 enters the examination passage 1 and walks through the place where the speed sensor 9 and the body thickness sensor 10 are installed, the speed sensor 9 The body thickness sensor 10 measures the speed of passing through the body 5 and measures the body thickness of the subject 4. These detection results are supplied to the X-ray inspection controller 6, and the X-ray inspection controller 6 adjusts the intensity of the X-ray source 2 and the sensitivity of the X-ray detector 3.
For a person walking at a low speed, the same clear X-ray transmission image can be obtained without the X-ray intensity required for a person walking at a high speed. X-ray exposure is reduced.
[0029]
In addition, a fat person or a person with a good physique has a large body thickness, and strong X-rays are required to transmit X-rays, whereas a thin person or a child has a short distance to transmit. Therefore, a transmitted image can be obtained with weak X-rays. The X-ray source 2 is adjusted to minimize X-ray exposure according to the physique of the person.
The human sensor 8 detects that the subject 4 has come to the imaging position 5 and gives an instruction signal to the X-ray inspection controller 6, which activates the X-ray source 2 and the X-ray detector 4. Then, an X-ray image is captured while the subject 4 passes through the imaging position 5. A foreign object is detected from the transmission image appearing in the X-ray image, and it is determined whether or not the object is a suspicious object such as a dangerous substance or a drug. When it is sufficient to detect a certain foreign matter, the foreign matter can be automatically detected by image processing using a pattern recognition method or the like. If there is no problem in the judgment result, the subject is allowed to enter through the exit opening / closing door 13, and if there is a problem, the side door 14 is opened and the subject 4 is guided to the detailed examination site to perform a detailed physical examination.
[0030]
The acquired X-ray images are stored in a database so that they can be reexamined later.
It is preferable that the video of the subject 4 acquired by the monitoring camera 12 be stored in the database in a state where it can correspond to the X-ray image. If an X-ray image is re-examined and a suspicious person is detected, if it is possible to make arrangements based on the stored images, the suspicious person can be found relatively easily even in a large airport, before it becomes important. To increase the possibility of avoiding danger.
[0031]
In the X-ray physical examination apparatus of the present embodiment, the subject 4 finishes the X-ray physical examination while walking and passing through the examination passage 1, so that the security examination can be efficiently executed without obstructing the flow of people. Airport and airplane safety can be ensured. In addition, since the X-ray imaging apparatus is installed in an inconspicuous state, the subject will be examined without any discomfort.
In the present embodiment, the X-ray source 2 and the X-ray detector 3 can be arranged below the floor of the examination passage 1 and above the ceiling, respectively.
[0032]
Further, a one-dimensional X-ray sensor such as a combination of a scintillator and a photodiode, a semiconductor detector, an ion chamber, or the like is used for the X-ray detector 3, and the X-ray source 2 has a vertically plate-shaped slit. Beams may be used. In such a combination, an X-ray transmission image of the whole body of the subject 4 can be obtained by collecting and synthesizing X-ray transmission image information while the subject 4 walks and crosses the X-ray slit beam.
Needless to say, the entrance opening / closing door 11 and the exit opening / closing door 13 may be a rotating bar, a swing door, a rotating door, or the like.
[0033]
Embodiment 2
The second embodiment shown in FIG. 2 is different from the first embodiment shown in FIG. 1 in that a belt conveyor on which a person rides and moves on an examination passage, that is, a so-called moving sidewalk is installed, and a slit-shaped X-ray source is provided. This is a security X-ray physical examination system that differs only in that an X-ray beam is used and a one-dimensional X-ray sensor is used as an X-ray detector. Note that the same reference numerals are given to the same elements as those in FIG. 1 to simplify the description.
[0034]
In the present embodiment, a belt conveyor 15 is laid in the inspection passage 1, and the subject 4 passes through the photographing position at a constant speed just by staying still on the conveyor 15. However, since there are people walking on the conveyor 15, the actual speed is measured using the speed sensor 9 to adjust the X-ray source 16.
Further, an X-ray source 16 for generating a slit beam having a plate shape in the vertical direction and an X-ray detector 17 in which a one-dimensional X-ray sensor is set in the vertical direction are used to generate an X-ray beam emitted from the X-ray source 16. The X-ray detector 17 is disposed so as to pass through the subject 4 obliquely from the front while passing through the imaging position 5 and enter the X-ray detector 17.
[0035]
In the X-ray physical examination apparatus according to the present embodiment, the subject 4 enters the examination passage 1, rides on the conveyor 15, passes in front of the speed sensor 9, and estimates the speed at which the subject 4 passes the imaging position 5. The thickness of the body of the subject 4 is measured by passing through the front of the thickness sensor 10, and the results are supplied to the X-ray inspection controller 6 to adjust the intensity of the X-ray source 2 and the sensitivity of the X-ray detector 3. .
With these adjustments, the output of the X-ray source 16 is reduced as much as possible to reduce the X-ray exposure of the subject 4.
[0036]
When the subject 4 reaches the imaging position 5, the human sensor 8 detects this and activates the X-ray source 16 and the X-ray detector 17 in the X-ray inspection control device 6 while the subject 4 passes through the imaging position 5. An X-ray image is taken.
A foreign object is detected from the transmission image appearing in the X-ray image, and when a suspicious object such as a dangerous substance or a drug is detected, the side door 14 is opened and the subject 4 is guided to the detailed inspection site to perform a detailed physical examination. . When no abnormality is detected, the lock of the exit opening / closing door 13 is released so that the user can go outside.
Other functions are the same as those described in FIG.
[0037]
【The invention's effect】
As described above, the security X-ray physical examination system of the present invention can efficiently acquire a clear X-ray image while a person is moving without being conscious of the examination apparatus, so that the airport and immigration control can be performed. By installing the equipment at a location and having all members, not just the suspects, undergo physical examinations, it is possible to reliably prevent dangerous goods from being brought on board or prohibited items from being brought into Japan.
[Brief description of the drawings]
FIG. 1 is a plan view of a security X-ray physical examination apparatus according to a first embodiment of the present invention.
FIG. 2 is a plan view of a security X-ray physical examination apparatus according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inspection passage 2, 16 X-ray source 3, 17 X-ray detector 4 Subject 5 Imaging position 6 X-ray inspection control device 7 Image display device 8 Human sensor 9 Speed sensor 10 Body thickness sensor 11 Entrance door 12 Surveillance camera 13 Exit Door 14 Side door 15 Belt conveyor

Claims (14)

An examination passage through which a person passes one by one, and an X-ray imaging apparatus including an X-ray source and an X-ray detector arranged to acquire an X-ray transmission image when a person passes a predetermined position of the examination passage, A speed sensor for measuring a moving speed of a person at a position before the predetermined position in the examination passage, measuring a moving speed of a subject to be inspected by the speed sensor, and determining the X-ray source based on the moving speed. An X-ray physical examination system for detecting an object worn by the subject based on an image signal output by performing X-ray imaging by adjusting the irradiation condition of the subject. The speed sensor illuminates from one side of the inspection passage, and on the other side, a large number of fiber ends are arranged in a line to detect the position of incident light, and a large number of photoelectric switches are arranged in rows. The security X-ray physical examination system according to claim 1, wherein the system is one of a sensor and an area sensor, or one of an image sensor and a speed gun. 2. The apparatus according to claim 1, further comprising a body thickness sensor for measuring a thickness of the body of the subject in the examination passage, and adjusting an irradiation condition of the X-ray source based on a measurement result of the body thickness sensor. Or the security X-ray physical examination system according to 2. The body thickness sensor illuminates from one side of the inspection passage, and on the other side, a number of fiber ends are arranged in a line to detect the position of incident light, and a number of photoelectric switches are arranged in a row. 2. The security X-ray physical examination system according to claim 1, wherein the sensor is one of an image sensor and an area sensor, or an image sensor. Further, a surveillance camera is installed in the examination passage, an image of the face or the whole body of the subject is acquired, and the acquired image is recorded in a database in association with the acquired image signal of the X-ray image. 5. The security X-ray physical examination system according to any one of items 1 to 4. A human sensor for detecting the presence of a subject at the predetermined position is provided, and the X-ray imaging apparatus is operated based on a detection signal of the human sensor to perform X-ray imaging. An X-ray physical examination system for security according to claim 1. The human sensor may be a contact switch driven by hands or feet, a load switch for detecting weight, a temperature sensor switch for detecting body temperature, a contact sensor, an ultrasonic sensor, or an infrared sensor. The X-ray inspection apparatus according to claim 6. The X-ray source and the X-ray detector are each arranged on a side portion of the inspection passage so that a straight line connecting the two passes through the predetermined position and intersects at an angle with the traveling direction of the inspection passage. The security X-ray physical examination system according to claim 1. The X-ray source and the X-ray detector are arranged under a ceiling and a floor of the inspection passage, respectively, such that a straight line connecting the two passes through the predetermined position and intersects at an angle in a traveling direction of the inspection passage. The security X-ray physical examination system according to claim 1. When the entrance of the inspection passage is provided with an entrance obstacle that blocks the passage of a person, and further provided with a human sensor that detects the presence of a person in the inspection passage, when the human sensor does not detect the presence of a person The security X-ray physical examination system according to any one of claims 1 to 9, wherein a person is allowed to enter the passage by passing through the entrance obstacle only. The security X-ray according to any one of claims 1 to 10, wherein the X-ray detector includes a one-dimensional X-ray sensor and performs imaging by moving relatively to an object. Physical examination system. The security X-ray physical examination system according to any one of claims 1 to 10, wherein the X-ray detector includes a two-dimensional X-ray sensor to collectively photograph an object. An exit obstacle is provided at the exit of the inspection passage, and a door is provided on a side portion that leads to a detailed inspection site. 13. The subject according to claim 1, wherein when the suspicious object is found, a door to the detailed inspection site is opened to guide the subject to the detailed inspection site. Security X-ray physical examination system. The security X-ray physical examination system according to any one of claims 1 to 13, wherein a conveyor is provided in the examination passage so that the subject is transported by the conveyor.

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