JP2013167530A - Line sensor and image pickup apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To capture an image of a measuring object without being affected by variation in a receiving element by using one receiving element for receiving thermal noise in a line sensor for receiving the thermal noise in a microwave band radiated from the measuring object such as a human body.SOLUTION: An inner tube 30 formed with a plurality of through-holes 32a-32H in a central axis direction is stored in an outer tube 20. The outer tube 20 is formed with slits 22A-22H along a spiral circulating around the central axis. The outer tube 20 is rotated about the central axis by a motor 14, the slits are sequentially overlapped with the through-holes for every prescribed rotation angle, and thermal noise radiated from the measuring object enters the inner tube 30 at positions facing each through-hole. One opening end of the inner tube 30 is closed, so that the thermal noise entering from each through-hole is radiated from the other opening, and the thermal noise is received by a receiving element 40. Consequently, the thermal noise for one line obtained via each through-hole can be measured as a pixel value.

Description

  The present invention relates to a line sensor that receives thermal noise in a microwave band radiated from a measurement object, and an imaging apparatus using the line sensor.

  Conventionally, by receiving thermal noise (preferably thermal noise in the millimeter wave band (30 GHz to 0.3 THz)) of the microwave band (0.3 GHz to 3 THz) radiated from the measurement target such as the human body, the measurement target It has been proposed to detect articles (weapons, smuggled goods, etc.) hidden in the measurement object from the captured images (see, for example, Patent Documents 1 and 2).

  Further, in this type of imaging apparatus, the thermal noise radiated from the measurement target is collected via a radio wave lens, thereby forming an image of the measurement target at a predetermined imaging position, and each part of the image Is detected via the receiving element.

  Since this receiving element needs to detect the reception level of radio waves with extremely high frequencies such as millimeter waves with high accuracy, the receiving element has a low noise amplifier that amplifies the received signal in addition to the receiving unit (antenna). Provided.

  Therefore, in this type of imaging apparatus, there is a problem in that if an imaging element in which a receiving element is arranged for each pixel of a captured image is used to image a measurement target, the cost increases. There is also a problem that it is difficult to two-dimensionally arrange the receiving elements incorporating the amplifiers at intervals at which images can be taken.

  For this reason, in this type of imaging apparatus, a line sensor in which receiving elements are arranged in one direction is usually used as an imaging element.

JP 2008-241352 A JP 2010-281737 A

  By the way, the line sensor is configured by arranging a large number of receiving elements in one direction, although the number of receiving elements can be reduced and the configuration can be simplified and the cost can be reduced as compared with the two-dimensional sensor. .

For this reason, there is a problem in that it is impossible to image the measurement object satisfactorily when there is a variation in characteristics among a plurality of receiving elements constituting the line sensor.
In order to reduce such variations in characteristics, it is sufficient to review the manufacturing process and inspection / adjustment process of the receiving element and use only the receiving element that provides the desired characteristics. There is a problem of increasing the cost of the sensor.

  The present invention has been made in view of these problems, and in a line sensor that receives thermal noise in a microwave band radiated from a measurement target such as a human body, the receiving element for receiving thermal noise is combined into one. An object of the present invention is to enable imaging of a measurement object without being affected by variations in receiving elements.

The invention according to claim 1, which has been made to achieve the object,
A line sensor that receives microwave band thermal noise radiated from a measurement object,
An inner cylinder formed in a bottomed cylindrical shape with one open end closed with a conductive material that blocks the passage of radio waves,
A plurality of through holes formed in the side wall of the inner cylinder at regular intervals in the direction of the central axis of the inner cylinder, and taking in thermal noise of the microwave band into the inner cylinder;
A conductive material that blocks the passage of radio waves, the inner cylinder can be stored so that the central axis coincides with the inner cylinder, and has an inner diameter that can rotate around the inner cylinder around the central axis An outer cylinder formed into a hollow cylinder,
It is formed on the side wall of the outer cylinder along a spiral turning around the central axis, and when the inner cylinder is housed in the outer cylinder and the outer cylinder is rotated around the central axis, One or more slits that sequentially overlap each through hole of the inner cylinder at every predetermined rotation angle of the outer cylinder, and guide the thermal noise of the microwave band to each through hole in turn,
By rotating the outer cylinder around the inner cylinder in a state where the inner cylinder is housed in the outer cylinder, the thermal noise of the microwave band is transferred from the slit to the inner cylinder through the through holes. Rotational drive means for incidence;
A receiving element that is disposed on the non-blocked opening side of the inner cylinder, is incident through each through-hole, and sequentially receives the thermal noise of the microwave band radiated from the opening;
The rotational driving means is rotated at a predetermined rotational speed, and the reception level of the thermal noise obtained via the receiving element is measured at every predetermined rotational angle of the outer cylinder where the slit and the through hole overlap. Control means to
It is provided with.

The invention according to claim 2 is the line sensor according to claim 1,
The outer cylinder is formed of a resin material capable of transmitting radio waves, and is rotatably accommodated around the central axis, and the inner cylinder, the rotation driving means, the receiving element, and the control means are positioned and accommodated. A resin case,
A display unit provided in the resin case;
The control means determines whether or not the reception level of the thermal noise obtained via the receiving element is greater than or equal to a preset threshold at every predetermined rotation angle of the outer cylinder, and the determination result Is displayed on the display unit.

The invention according to claim 3
A radio wave lens that forms an image of the measurement object by transmitting the thermal noise of the microwave band emitted from the measurement object;
A reflector that reflects the thermal noise of the microwave band emitted from the measurement object toward the radio wave lens;
Scanning means for changing a center line of a measurement object imaged by the radio wave lens in a predetermined scanning direction by rotating the reflecting plate around a rotation axis penetrating the reflecting plate in a plate surface direction;
A line sensor that is disposed so as to face the center line of the measurement object imaged by the radio wave lens, and that receives thermal noise of the center line;
Image data generating means for sequentially acquiring thermal noise for one line from the line sensor in synchronization with rotation of the reflecting plate by the scanning means, and generating image data of the measurement object from the received level of the received thermal noise When,
An imaging device comprising:
The line sensor according to claim 1 is provided as the line sensor.

The line sensor according to claim 1 includes a bottomed cylindrical inner cylinder and an outer cylinder that accommodates the inner cylinder and is rotatable about the central axis of the inner cylinder.
Further, a through hole is formed in the side wall of the inner cylinder at a certain interval in the central axis direction, and one or more slits are formed in the side wall of the outer cylinder along a spiral turning around the central axis. Is formed.

  In addition, when the inner cylinder is housed inside the outer cylinder and the outer cylinder is rotated about the central axis, the slit overlaps with each through hole of the inner cylinder in order for each predetermined rotation angle of the outer cylinder. It is formed so as to guide the thermal noise of the wave band to each through hole in turn.

  Further, the outer cylinder is provided with a rotation driving means for rotating the outer cylinder around the inner cylinder in a state in which the inner cylinder is accommodated in the outer cylinder. A receiving element is provided for receiving the thermal noise of the microwave band incident on the inside and radiated from the opening.

  Then, the control means rotates the rotation driving means at a predetermined rotation speed and measures the reception level of the thermal noise obtained through the receiving element at every predetermined rotation angle of the outer cylinder where the slit and the through hole overlap. To do.

  Therefore, according to the line sensor of the present invention, if the through-hole drilled in the side wall of the inner cylinder is arranged so as to face the measurement target such as a human body, the radiation is emitted from the position facing the measurement target through-hole. The thermal noise in the microwave band is incident on the inner cylinder in order along the arrangement direction of the through holes, and the signal level is sequentially measured by one receiving element.

  Therefore, according to the line sensor of the present invention, the measurement object is scanned in one direction along the central axis of the inner cylinder and the outer cylinder, and the signal level of the thermal noise radiated from each position on the scanning line is measured. It will be possible.

  Therefore, from the measurement result, for example, if there is a part whose signal level is lower than other parts, it can be detected that an object that blocks the thermal noise radiated from the measurement target exists in that part.

  Therefore, the line sensor of the present invention can be used as a line sensor for detecting articles (weapons, smuggled goods, etc.) hidden in the measurement object as described in Patent Documents 1 and 2 mentioned above. It becomes.

  As described above, the line sensor of the present invention can measure the signal level of the thermal noise radiated from a plurality of locations on the scanning line by using one receiving means, so that it is lower than the conventional line sensor described above. It can be realized at a cost.

  Further, unlike the conventional line sensor, the measurement result of the thermal noise does not vary due to variations in the characteristics of a plurality of receiving means, so if the measurement target is imaged using the line sensor of the present invention, A good captured image can be obtained without being affected by variations in the characteristics of the receiving means.

Next, according to the line sensor of the second aspect, the respective parts are accommodated in the resin case, and the outer cylinder is accommodated in the resin case so as to be rotatable around the central axis.
The resin case is provided with a display unit, and the control means determines whether or not the reception level of the thermal noise obtained via the receiving element for each predetermined rotation angle of the outer cylinder is greater than or equal to a preset threshold value. And the determination result is displayed on the display unit.

  Therefore, according to the line sensor of the present invention, if the user holds the resin case in his / her hand and arranges the through-hole to face the object to be measured, the reception level is higher than the threshold (or lower than the threshold) on the display unit. Thus, the part where the thermal noise is radiated from the measurement target (or the part where the thermal noise is blocked) is displayed.

  Therefore, by using the line sensor of the present invention, the user can easily inspect whether or not an object (for example, a dangerous object such as a weapon or a contraband) is hidden in the measurement object. Will be able to.

  In addition, if the line sensor is moved in a direction orthogonal to the arrangement direction of the through holes in a state where the through holes are directed to the measurement target, the surface of the measurement target can be scanned two-dimensionally, From the display result, it can be detected more accurately that the article is hidden in the measurement target.

  On the other hand, according to the imaging device of claim 3, the reflector reflects the thermal noise of the microwave band emitted from the measurement object toward the radio wave lens, and the microwave lens transmits the thermal noise. Then, an image of the measurement object is formed.

  In addition, the reflecting plate is rotated around a rotation axis that penetrates the reflecting plate in the plate surface direction by the scanning unit, and the rotation causes the center line of the measurement target imaged by the radio wave lens to be in a predetermined scanning direction. Change.

  A line sensor is arranged for the measurement target image formed by the radio wave lens so as to face the center line of the image, and the line sensor sequentially changes by scanning by the scanning means. Thermal noise for one line to be measured is measured by a line sensor.

  Pixel data for one line (thermal noise reception level) obtained by this line sensor is sequentially taken in by the image data generation means in synchronization with the rotation of the reflection plate by the scanning means. Then, the image data generation means generates image data to be measured from the received reception level of the thermal noise.

  As described above, in the imaging apparatus of the present invention, the measurement target is scanned in one direction by rotating the reflecting plate, and one line of pixel data (thermal noise reception level) that changes due to the scanning is displayed on the line. By measuring with a sensor, an image to be measured is taken.

And in this invention, the line sensor of this invention (Claim 1) is utilized as a line sensor used for the imaging.
Therefore, according to the image pickup apparatus of the present invention, the cost can be reduced compared to the conventional image pickup apparatus described above, and a two-dimensional image can be picked up by only one receiving means. It is possible to eliminate characteristic variation and capture a clear two-dimensional image.

1 shows a configuration of a handy scanner according to the first embodiment, in which (a) is a side view thereof, (b) is a cross-sectional view viewed from the same direction as (a), and (c) is a cross-sectional view taken along line II shown in (b). FIG. It is a side view showing the structure of an outer cylinder and an inner cylinder. It is a block diagram showing the circuit structure of the handy scanner of 1st Embodiment. It is a flowchart showing the control processing implemented with the control circuit of 1st Embodiment. It is explanatory drawing explaining the usage method and example of a display of the handy scanner of 1st Embodiment. It is a schematic block diagram showing the structure of the whole inspection system of 2nd Embodiment. It is a block diagram showing the structure of the imaging device of 2nd Embodiment. It is a flowchart showing the imaging process implemented in the control circuit of 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
The handy scanner 2 of this embodiment has a function as a line sensor of the present invention (Claims 1 and 2), and is used to manually check whether passengers do not conceal dangerous goods at airports or the like. Is.

  As shown in FIG. 1A, a handy scanner 2 includes a rod-shaped main body 4 for receiving millimeter-wave band thermal noise radiated from a measurement object such as a human body, and one longitudinal end of the main body 4. And a grip portion 6 that is extended to the side and is held by the user.

The external appearances of the main body 4 and the grip 6 are cylindrical, and the grip 6 has a smaller diameter than the main body 4.
A large number (eight in this embodiment) of LEDs 8A to 8H are provided on the side surface of the main body 4 along the longitudinal direction (center axis direction) of the main body 4 at substantially equal intervals. These LEDs 8 </ b> A to 8 </ b> H are provided in the main body unit 4 for displaying a portion where the thermal noise in the millimeter wave band radiated from the measurement target cannot be received when the main body unit 4 is arranged along the measurement target. The display substrate 44 is assembled (see FIG. 1C, FIG. 3, etc.).

  Next, as shown in FIGS. 1B and 1C, the main body 4 has various types of resin described below in a resin case 10 formed in a hollow cylindrical shape with a synthetic resin capable of transmitting radio waves. The grip portion 6 is formed integrally with the resin case 10.

  That is, in the resin case 10, an outer cylinder 20 that is formed into a cylindrical shape with a conductive material (specifically, metal) that blocks the passage of radio waves and in which an inner cylinder 30 with a small diameter is accommodated is accommodated. Has been.

  The inner diameter of the outer cylinder 20 is slightly larger than the outer diameter of the inner cylinder 30 so that the outer cylinder 20 can rotate around the inner cylinder 30 accommodated in the center. The outer cylinder 20 is fixed in the resin case 10 via bearings 12A and 12B provided at both ends in the longitudinal direction.

  The bearings 12A and 12B are well-known roller bearings in which four rollers 13 are distributed around the central axis, and the outer cylinder 20 is fixed in the resin case 10 via the bearings 12A and 12B. Within the resin case 10, it can rotate around the central axis.

  In the resin case 10, a motor 14 for rotating the outer cylinder 20 around the central axis is provided with a synthetic resin fixing member 18 on one end side in the longitudinal direction of the outer cylinder 20 (left end side in FIG. 1). Is fixed through.

The motor 14 is provided with an encoder 16 for detecting the rotation angle of the motor 14 (and thus the outer cylinder 20).
On the other hand, as shown in FIG. 2, the inner cylinder 30 is closed at the one end side in the central axis direction (the left end side in FIGS. 1 and 2) on the motor 14 side in the resin case 10 and is closed at the other end side (FIG. 1). 2 is provided on the peripheral edge of the opening (on the right end side).

  The diameter of the flange 34 is larger than the outer diameter of the outer cylinder 20, and when the inner cylinder 30 is stored in the outer cylinder 20, the opening end of the outer cylinder 20 is brought into contact with the flange 34, The relative positions of the outer cylinder 20 and the inner cylinder 30 in the central axis direction are positioned.

In addition, the flange 34 is used to fix the inner cylinder 30 in the resin case 10 so as not to rotate by being fixed in the resin case 10.
Next, like the outer cylinder 20, the inner cylinder 30 is formed in a bottomed cylinder shape with one open end closed by a conductive material (specifically, metal) that blocks the passage of radio waves. .

  As shown in FIGS. 2 and 3, a plurality of (eight in this embodiment) through-holes 32 </ b> A to 32 </ b> A are formed on the side wall of the inner cylinder 30 at a constant interval in the central axis direction of the inner cylinder 30. 32H is drilled.

  The interval between the through holes 32A to 32H is the same as the interval between the LEDs 8A to 8H. In the state where the inner cylinder 30 is housed in the resin case 10 together with the outer cylinder 20, the through holes 32A are arranged in the central axis direction of the resin case 10. The positions of .about.32H and the LEDs 8A to 8H coincide with each other.

The inner cylinder 30 configured in this manner is used as a so-called waveguide that radiates millimeter-wave band thermal noise incident from the through holes 32A to 32H from the opening on the flange 34 side.
In the inner cylinder 30, a radio wave absorber 36 is provided at the bottom which is one of the closed open ends (see FIG. 2).

  This radio wave absorber 36 prevents millimeter-wave band thermal noise incident from the through holes 32 </ b> A to 32 </ b> H from being reflected at the bottom and radiating thermal noise having different phases from the opening on the flange 34 side. Is.

Next, as shown in FIG. 2, a plurality of (eight in the present embodiment) slits 22 </ b> A to 22 </ b> H are formed on the side wall of the outer cylinder 20 along a spiral that turns around the central axis of the outer cylinder 20. ing.
The intervals in the central axis direction of the slits 22A to 22H are set so as to coincide with the through holes 32A to 32H of the inner cylinder 30, and the positions of the slits 22A to 22H in the circumferential direction of the outer cylinder 20 are It is set for each angle (in this embodiment, every 45 °) obtained by dividing the entire circumference of the outer cylinder 20 by the number of slits 22A to 22H.

  That is, each of the slits 22A to 22H accommodates the inner cylinder 30 in the outer cylinder 20 and rotates the outer cylinder 20 around the central axis at every predetermined rotation angle (in this embodiment). , 0 °, 45 °, 90 °, 135 °, 180 °, 225 °, 270 °, and 315 °), the slits 22A to 22H are formed so as to overlap the through holes 32A to 32H in order. Yes.

  As a result, when the inner cylinder 30 is housed in the outer cylinder 20 and the outer cylinder 20 is rotated about the central axis, thermal noise in the microwave band is transmitted from the slits 22A to 22H to the through-hole 32A in synchronization with the rotation. It will inject into the inner cylinder 30 in order through -32H.

  The thermal noise incident in order from the through holes 32A to 32H is guided to the flange 34 side in the inner cylinder 30 and radiated from the opening on the flange 34 side. A receiving element 40 for receiving noise is disposed (see FIGS. 1B and 3).

  The receiving element 40 is a unit in which a receiving unit (antenna) that receives thermal noise in the millimeter wave band and a low noise amplifier that amplifies the received signal are integrated, and the rear end side is made of a synthetic resin. It is fixed in the resin case 10 via a fixing member 19.

Next, the received signal from the receiving element 40 is input to a control board 42 disposed outside the side wall of the outer cylinder 20 in the resin case 10 as shown in FIGS. .
As shown in FIG. 3, the control board 42 detects a received signal from the receiving element 40 and outputs a detection voltage corresponding to the signal level, and a drive circuit for driving the motor 14. 48 and the motor 14 (and thus the outer cylinder 20) are rotated via the drive circuit 48 and the detection voltage is taken in from the processing circuit 46, so that the main body 4 (in other words, the outer cylinder 20 and the inner cylinder 30). A control circuit 50 that measures the signal level of the received signal for one line along the central axis is mounted.

  The control circuit 50 is configured by a known microcomputer including a CPU, a ROM, a RAM, and the like. By turning on the LEDs 8A to 8H provided on the display substrate 44 in accordance with the measurement result, the control circuit 50 corresponds to one line. The position where the thermal noise from the measurement object cannot be received on the scanning line is displayed.

Hereinafter, the control process executed by the control circuit 50 will be described with reference to the flowchart shown in FIG.
This control process is performed when the user grips the grip 6 and turns on the power switch (not shown) of the handy scanner 2 to supply power to the control circuit 50. This process is repeatedly executed when the CPU executes a control program stored in the ROM.

  As shown in FIG. 4, when the control process is started, first, in S110 (S represents a step), the rotational position of the motor 14 (and thus the outer cylinder 20) detected by the encoder 16 is predetermined. The motor 14 is driven via the drive circuit 48 so as to be the origin position (for example, a position where the rotation angle of the outer cylinder 20 is an intermediate angle from 315 ° to 0 ° and no thermal noise is incident on the receiving element 40); The initialization process (initialization) is executed.

  In subsequent S120, a calibration process is performed to adjust the circuit characteristics (eg, detection characteristics) of the processing circuit 46 so that the detection voltage input via the processing circuit 46 has a predetermined initial value.

  Next, in S <b> 130, scanning of the measurement target is started in which the motor 14 (and thus the outer cylinder 20) is rotated at a constant speed via the drive circuit 48 and the reception signal from the reception element 40 is captured.

  When scanning is started in this way, the process proceeds to S140, and the processing circuit 46 is set for each rotation angle range in which the through holes 32A to 32H of the inner cylinder 30 and the slits 22A to 22H of the outer cylinder 20 partially overlap. The reception signal level reading process of reading the signal level of the reception signal from the reception element 40 is executed.

  Next, in S150, it is determined whether or not the received signal level reading process in S140 has been performed for all the angle ranges where the through holes 32A to 32H of the inner cylinder 30 and the slits 22A to 22H of the outer cylinder 20 overlap. to decide.

  If reading has not been completed in the entire angle range, the process proceeds to S140. If reading has been completed in the entire angle range, in S160, the motor 14 (and thus the outer cylinder 20) is driven ( That is, scanning is stopped, and the process proceeds to S170.

  In S170, the signal level of the received signal read for each angle range in which the through holes 32A to 32H of the inner cylinder 30 and the slits 22A to 22H of the outer cylinder 20 overlap in S140, and the level change (differential value of the signal level) Based on the above, it is determined whether or not the millimeter-wave band thermal noise radiated from the measurement object is normally received by the receiving element 40 for each angle range.

  In subsequent S180, based on the determination processing result in S170, the thermal noise in the millimeter wave band is received within the angular range in which the through holes 32A to 32H of the inner cylinder 30 and the slits 22A to 22H of the outer cylinder 20 overlap. It is determined whether or not there is an unreceived area that is not received by the element 40.

  If it is determined in S180 that there is no unreceived area, the control process is temporarily terminated. Conversely, if it is determined in S180 that there is an unreceived area, it is provided on the display substrate 44. After the LEDs at the positions corresponding to the unreceived areas among the LEDs 8A to 8H are turned on, the control process is temporarily terminated.

Note that after the control process ends, the process proceeds to S110 again. As a result, the control process is repeatedly executed at regular intervals.
As described above, according to the handy scanner 2 of the present embodiment, the outer cylinder 20 is rotated around the inner cylinder 30 via the motor 14 so that the outer cylinder 20 is rotated at every predetermined rotation angle (this embodiment). Then, every 45 °), in order from the through holes 32A formed in the side wall of the inner cylinder 30 to the through holes 32B, 32C,. The signal level of the thermal noise is measured in order using the receiving element 40.

  Therefore, according to the handy scanner 2 of the present embodiment, as shown in FIG. 5A, the through holes 32A to 32H drilled in the side wall of the inner cylinder 30 are arranged so as to face the inspection subject 52. If the control circuit 50 is caused to execute the control process, it is possible to measure the radiation level of the thermal noise at the position facing the through holes 32A to 32H of the person 52 to be inspected.

  Moreover, if there is a position where the thermal noise cannot be received at a position facing the through holes 32A to 32H of the person to be inspected 52, an LED corresponding to the position is turned on. For this reason, the user of the handy scanner 2 simply inspects at the airport or the like that the passenger who is the inspection target 52 conceals an article (dangerous material) that blocks the passage of millimeter-wave thermal noise. be able to.

  Further, the handy scanner 2 of the present embodiment is a line sensor that receives thermal noise radiated from a measurement target on a linear scanning line along the central axis direction of the inner cylinder 30 and the outer cylinder 20. Each time the cylinder 20 makes one rotation, the measurement result of the thermal noise is displayed via the LEDs 8A to 8H.

  Therefore, in the handy scanner 2 of the present embodiment, as shown in FIG. 5A, the user holds the grip 6 and holds the inner cylinder 30 and the outer cylinder 20 along the body of the person 52 to be inspected. If the handy scanner 2 is moved in the manual scanning direction perpendicular to the central axis of the center axis, the measurement result is displayed every rotation of the outer cylinder 20 along the manual scanning direction.

  And since the display of the measurement result changes as illustrated in FIG. 5B, for example, when the person 52 to be inspected conceals the article, the user determines the position of the LED to be lit and the lighting thereof. The shape of the article can be recognized from the change in the number, and from the shape, it can be determined whether or not the article hidden by the person to be inspected 52 is a dangerous article.

  Further, as described above, the handy scanner 2 of the present embodiment can realize the function as a line sensor with only one receiving element 40, so that it is extremely low in cost as compared with the above-described conventional line sensor. realizable.

  In addition, by using a plurality of receiving elements as in the case of a conventional line sensor, it is not affected by variations in characteristics between receiving elements, so that it is possible to accurately measure the thermal noise for one measurement target line. The position and shape of the article can be accurately recognized from the measurement result.

In the present embodiment, the drive circuit 48 provided on the motor 14 and the control board 42 corresponds to the rotation driving means of the present invention, and the LEDs 8A to 8H provided on the display board 44 are the display unit of the present invention. The control circuit 50 provided on the control board 42 corresponds to the control means of the present invention.
[Second Embodiment]
Next, as a second embodiment of the present invention, a description will be given of an imaging system that incorporates the function as a line sensor in the handy scanner 2 of the first embodiment into the imaging device 60 and images the subject 52 to be inspected.

  As shown in FIG. 6, the imaging system according to the present embodiment includes an imaging device 60 that captures the inspection subject 52 by receiving millimeter-wave band thermal noise from the inspection subject 52 in the inspection target region, and the inspection target. It is comprised from the shielding board 54 provided in the opposite side to the imaging device 60 across the area | region.

The shielding plate 54 is for blocking unnecessary thermal noise that enters from the rear side of the person to be inspected 52 when viewed from the imaging device 60, and is made of a metal plate.
In addition, as shown in FIG. 7, the imaging device 60 takes in millimeter-wave band thermal noise radiated from the person being inspected 52 through the radio wave transmitting unit 62, and reflects the reflecting plate 64, the lens 66, and the reflecting plate. It is configured to guide the line sensor 70 through 68.

  Here, the lens 66 is disposed in the imaging device 60 so that the central axis is in the vertical direction, and the reflection plate 64 and the reflection plate 68 are disposed above and below the lens 66 with the lens 66 interposed therebetween. .

The reflecting plate 64 is for reflecting the millimeter-wave band thermal noise radiated from the subject and entering the imaging device 60 via the radio wave transmitting unit 62 toward the lens 66.
From left and right side edges of the reflecting plate 64, support shafts 72 are rotatably provided around the rotating shaft in the horizontal direction along the plate surface of the reflecting plate 64 so as to support the reflecting plate 64 in a rotatable manner. ing. The support shaft 72 is rotatably fixed to the inner wall of the case of the imaging device 60.

Further, the upper end portion of the back surface of the reflecting plate 64 (the surface opposite to the radio wave transmitting portion 62) is connected to a disc 76 provided on the rotating shaft 75 of the motor 74 via a link 78.
This is because the reflection plate 64 is rotated around a rotation axis formed by the support shaft 72 within a predetermined angle range by the rotation of the motor 74 (and thus the disc 76).

  Then, by rotating the reflecting plate 64 in this manner, the inspection subject 52 is scanned in the vertical direction, and the lens 66 is inspected with an arbitrary horizontal line in the vertical direction as a center line. The image of the subject 52 is incident.

  Note that the case of the imaging device 60 is formed in a rectangular box shape with a metal material capable of shielding radio waves except for the radio wave transmission part 62, and millimeter waves incident on the case are formed on the inner wall surface of the case. A radio wave absorber is provided so as not to be reflected and diffused by the inner wall surface of the case.

Next, the lens 66 forms an image of the person 52 to be inspected at the position where the lower reflection plate 68 is disposed by transmitting the millimeter-wave band thermal noise that has entered through the reflection plate 64. .
The reflection plate 68 is for reflecting the thermal noise transmitted through the lens 66 in the vertical direction at the position where the subject image is formed by the lens 66 toward the line sensor 70 in the horizontal direction.

  Then, as described above, the image of the person 52 to be inspected that is incident on the lens 66 through the reflector 64 and is imaged at the position of the reflector 68 through the lens 66 is vertical by the rotation of the reflector 64. Since the image is scanned in the direction, an image (that is, thermal noise) for one line corresponding to each scanning position in the vertical direction is incident on the line sensor 70.

  Therefore, in synchronization with the rotation of the reflecting plate 64 (in other words, vertical scanning), the thermal noise for one line measured by the line sensor 70 is sequentially taken in, so that a two-dimensional image of the person to be inspected 52 is obtained. Can be imaged.

  Next, the line sensor 70 of the present embodiment is a motor that rotates the outer cylinder 20 around the outer cylinder 20 and the inner cylinder 30 and the inner cylinder 30 in the same manner as the line sensor constituting the handy scanner 2 of the first embodiment. 14, an encoder 16, and a receiving element 40 that receives millimeter-wave band thermal noise radiated from the flange 34 side opening of the inner cylinder 30.

  Note that the number of slits 22 and through holes 32 formed in the outer cylinder 20 and the inner cylinder 30 is larger than that in the first embodiment, thereby reducing the horizontal resolution of a two-dimensional image that can be captured. It is high.

  In the line sensor 70, the central axis of the inner cylinder 30 is in the horizontal direction parallel to the reflecting surface of the reflecting plate 68, and each through hole 32 formed in the inner tube 30 faces the reflecting surface of the reflecting plate 68. Is arranged.

  Similarly to the handy scanner 2 of the first embodiment, the line sensor 70 is connected to a processing circuit 46 for detecting a received signal from the receiving element 40 and a driving circuit 48 for driving the motor 14. The processing circuit 46 and the drive circuit 48 are connected to the control circuit 90 in the imaging device 60 together with the encoder 16 in the line sensor 70.

  The control circuit 90 is configured by a known microcomputer including a CPU, ROM, RAM, and the like. The control circuit 90 includes an encoder 80 that is provided on the support shaft 72 of the reflecting plate 64 and detects the rotational position of the reflecting plate 64, a driving circuit 82 that drives the motor 74 to rotate, and an outside of the imaging device 60. A display device 84 for displaying a captured image provided in is also connected.

  The control circuit 90 controls the vertical scanning position of the person 52 to be inspected by the reflector 64 by rotating the motor 74 via the drive circuit 82, and at each vertical scanning position, the same as in the first embodiment. In addition, the line sensor 70 is driven via the drive circuit 48 to capture the thermal noise for one scanning line in the horizontal direction, thereby executing imaging processing for generating millimeter wave image data of the person 52 to be inspected.

Hereinafter, the imaging process executed by the control circuit 90 will be described with reference to the flowchart shown in FIG.
This imaging process is a process repeatedly executed in the control circuit 90 when the operation mode of the control circuit 90 is set to the imaging mode of the image.

  As shown in FIG. 8, when the imaging process is started, first, in S210, the motors 74 and 14 are driven via the drive circuits 82 and 48, so that the reflector 64 and the outer cylinder 20 are respectively encoders. Initialization processing (initialization) for positioning to a predetermined origin position detected at 80 and 16 is executed.

  Next, in S220, calibration processing is performed to adjust the circuit characteristics of the processing circuit 46 so that the detection voltage input through the processing circuit 46 becomes a predetermined initial value. In S230, the drive circuit 48 is turned on. Then, the motor 14 (and thus the outer cylinder 20) is rotated at a constant speed to take in the received signal from the receiving element 40, and horizontal scanning is started.

  When scanning is started in this way, the process proceeds to S240, and the reception signal level reading process is executed in the same procedure as in S140 of FIG. 4, and in the subsequent S250, the reception signal level of S240 is determined in the same manner as in S150 of FIG. It is determined whether or not the reading process has been executed for all angle ranges in which the through hole 32 of the inner cylinder 30 and the slit 22 of the outer cylinder 20 overlap.

  If the reading is not completed in the entire angle range, the process proceeds to S240. If the reading is completed in the entire angle range, the motor 14 of the line sensor 70 (and thus the outer cylinder 20 is extended) in S260. ) Driving (that is, scanning) is stopped, and the flow proceeds to S270.

  In S270, the signal level of the received signal read for each angle range in which the through hole 32 of the inner cylinder 30 and the slit 22 of the outer cylinder 20 overlap in S240 is used as the pixel value for one horizontal scan of the person to be inspected 52. It memorize | stores in memory (RAM etc.).

  In the subsequent S280, it is determined whether or not the reading processing of the pixel values for one horizontal scanning line in S230 to S270 has been executed for the entire vertical scanning range by the reflector 64, thereby determining the pixels for the entire vertical scanning range. Determine whether reading of values is complete.

  If it is determined in S280 that reading of the pixel values for the entire vertical scanning range is not completed, the process proceeds to S290, and the motor 74 is driven via the drive circuit 82, so that the reflector 64 is moved to a predetermined angle. And the vertical scanning position by the reflecting plate 64 is changed to the next scanning position.

Thereafter, the process proceeds to S230 again, and a series of processes (S230 to S270) for reading pixel values for one horizontal scanning line at the vertical scanning position are executed again.
On the other hand, if it is determined in S280 that the reading of the pixel values for the entire vertical scanning range has been completed, the process proceeds to S300, and one of the inspection subjects 52 is based on the read pixel values for the entire vertical scanning range. Image data (two-dimensional image data) for the screen is generated.

  In S310, the generated image data for one screen is output to the external display device 84 to display the captured image of the person 52 to be inspected on the display device 84, and the image data is stored in the external storage device. (Hard disk or the like; not shown) and the imaging process is temporarily terminated.

  As a result, the user of the imaging device 60 of the present embodiment can detect that the inspection target person 52 is in the inspection target area by looking at the captured image displayed on the display device 84, It is possible to detect hidden articles (dangerous goods).

  In the imaging system of the present embodiment, as the line sensor 70 incorporated in the imaging device 60, the outer cylinder 20 and the inner cylinder 30, and the outer cylinder 20 around the inner cylinder 30, as in the handy scanner 2 of the first embodiment. The rotating motor 14, the encoder 16, and a receiving element 40 that receives millimeter-wave band thermal noise radiated from the flange 34 side opening of the inner cylinder 30 are connected to the processing circuit 46 and the driving circuit 48. A line sensor is used.

  For this reason, according to the imaging device 60 of the present embodiment, the cost can be reduced as compared with the conventional imaging device, and variations in characteristics of each pixel of the captured image are eliminated, and a clear two-dimensional image is obtained. be able to.

  In this embodiment, the lens 66 corresponds to the radio wave lens of the present invention, the reflection plate 64 corresponds to the reflection plate of the present invention, and the motor 74, the encoder 80, and the drive circuit 82 include the scanning of the present invention. Corresponds to means.

The control circuit 90 has functions as the scanning unit and the image data generation unit of the present invention. In particular, among the imaging processes executed by the control circuit 90, the processes in S210 and S290 correspond to the scanning unit. The processes of S230 to S280, S300, and S310 correspond to image data generation means.
[Modification]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various aspect can be taken in the range which does not deviate from the summary of this invention.

  For example, in the first embodiment, the measurement result is described as being notified to the user by turning on the LEDs 8A to 8H. However, the measurement result uses a display panel that can display two-dimensional information such as a liquid crystal display panel. Then, the user may be notified.

In addition, although the outer cylinder 20 has been described as being formed with a plurality of slits 22 along a spiral, one spiral slit may be formed.
In the second embodiment, the reflecting plate 64 is stopped at a predetermined scanning angle position, and then the outer cylinder 20 of the line sensor 70 is rotated to capture pixel values for one horizontal scanning line. Further, by synchronizing the rotation of the reflecting plate 64 and the rotation of the outer cylinder 20, the pixel values for all the vertical and horizontal scanning lines may be taken in continuously.

  Further, in each of the above embodiments, the line sensor has been described as receiving thermal noise in the millimeter wave band radiated from the inspecting person 52 as the measurement target, but thermal noise composed of microwaves other than the millimeter wave band. May be received.

  DESCRIPTION OF SYMBOLS 2 ... Handy scanner, 4 ... Main-body part, 6 ... Holding part, 8A-8H ... LED, 10 ... Resin case, 12A, 12B ... Bearing, 13 ... Roller, 14 ... Motor, 16 ... Encoder, 18, 19 ... Fixing member 20 ... outer cylinder, 22, 22A-22H ... slit, 30 ... inner cylinder, 32, 32A-32H ... through hole, 34 ... collar, 36 ... radio wave absorber, 40 ... receiving element, 42 ... control board, 44 DESCRIPTION OF SYMBOLS ... Display board, 46 ... Processing circuit, 48 ... Drive circuit, 50 ... Control circuit, 52 ... Inspection subject, 54 ... Shield plate, 60 ... Imaging device, 62 ... Radio wave transmission part, 64, 68 ... Reflection plate, 66 ... Lens, 70 ... Line sensor, 72 ... Support shaft, 74 ... Motor, 75 ... Rotating shaft, 76 ... Disk, 78 ... Link, 80 ... Encoder, 82 ... Drive circuit, 84 ... Display device, 90 ... Control circuit.

Claims (3)

A line sensor that receives microwave band thermal noise radiated from a measurement object,
An inner cylinder formed in a bottomed cylindrical shape with one open end closed with a conductive material that blocks the passage of radio waves,
A plurality of through holes formed in the side wall of the inner cylinder at regular intervals in the direction of the central axis of the inner cylinder, and taking in thermal noise of the microwave band into the inner cylinder;
A conductive material that blocks the passage of radio waves, the inner cylinder can be stored so that the central axis coincides with the inner cylinder, and has an inner diameter that can rotate around the inner cylinder around the central axis An outer cylinder formed into a hollow cylinder,
It is formed on the side wall of the outer cylinder along a spiral turning around the central axis, and when the inner cylinder is housed in the outer cylinder and the outer cylinder is rotated around the central axis, One or more slits that sequentially overlap each through hole of the inner cylinder at every predetermined rotation angle of the outer cylinder, and guide the thermal noise of the microwave band to each through hole in turn,
By rotating the outer cylinder around the inner cylinder in a state where the inner cylinder is housed in the outer cylinder, the thermal noise of the microwave band is transferred from the slit to the inner cylinder through the through holes. Rotational drive means for incidence;
A receiving element that is disposed on the non-blocked opening side of the inner cylinder, is incident through each through-hole, and sequentially receives the thermal noise of the microwave band radiated from the opening;
The rotational driving means is rotated at a predetermined rotational speed, and the reception level of the thermal noise obtained via the receiving element is measured at every predetermined rotational angle of the outer cylinder where the slit and the through hole overlap. Control means to
A line sensor comprising: The outer cylinder is formed of a resin material capable of transmitting radio waves, and is rotatably accommodated around the central axis, and the inner cylinder, the rotation driving means, the receiving element, and the control means are positioned and accommodated. A resin case,
A display unit provided in the resin case;
The control means determines whether or not the reception level of the thermal noise obtained via the receiving element is greater than or equal to a preset threshold at every predetermined rotation angle of the outer cylinder, and the determination result The line sensor according to claim 1, wherein: is displayed on the display unit. A radio wave lens that forms an image of the measurement object by transmitting the thermal noise of the microwave band emitted from the measurement object;
A reflector that reflects the thermal noise of the microwave band emitted from the measurement object toward the radio wave lens;
Scanning means for changing a center line of a measurement object imaged by the radio wave lens in a predetermined scanning direction by rotating the reflecting plate around a rotation axis penetrating the reflecting plate in a plate surface direction;
A line sensor that is disposed so as to face the center line of the measurement object imaged by the radio wave lens, and that receives thermal noise of the center line;
Image data generating means for sequentially acquiring thermal noise for one line from the line sensor in synchronization with rotation of the reflecting plate by the scanning means, and generating image data of the measurement object from the received level of the received thermal noise When,
An imaging device comprising:
An imaging apparatus comprising the line sensor according to claim 1 as the line sensor.

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