JP5851701B2 - Camera device for monitoring under radiation environment - Google Patents

Description

  The present invention relates to a surveillance camera device that captures an image for the purpose of checking the situation in a space in a radioactive environment or for security purposes, and in particular, is attached to a wall that blocks radiation and shields the room in a radiation environment that is shielded by the wall from the outside The present invention relates to a camera device for monitoring under a radiation environment suitable for monitoring.

  In the use of nuclear power, fuel is made of plutonium and used as part of the fuel in conventional thermal neutron reactors. This is also an important issue in the transfer process. Currently, this confirmation recording system is implemented by an optical monitoring system constructed by IAEA (World Atomic Energy Agency). The state is photographed by a dedicated radiation-resistant camera and converted into a video signal, which is then sent to a monitoring and recording device for storage.

An example of a conventional camera device for monitoring under a radiation environment used for this purpose is shown in FIG.
A space in a radioactive environment such as a warehouse in which high-level radioactive waste or the like is stored is partitioned by a radiation shielding wall 30. A cylindrical protective case 1 is embedded in the shielding wall 30 so as to penetrate the radiation shielding wall 30.

  The front end surface of the protective case 1 is covered with a radiation resistant glass 5 attached with a mounting bolt 6. The radiation resistant glass 5 is a transparent glass plate that blocks radiation and transmits light. Two cameras 2 and 3 are fixed to the camera support 4 at the tip of the protective case 1 covered with the radiation-resistant glass 5, and these cameras 2 and 3 shield the radiation through the radiation-resistant glass 5. A subject to be photographed existing in the inner space covered with the wall 30 is photographed.

  Shields 7 and 8 are provided behind the cameras 2 and 3 in the protective case 1 to shield radiation. The shields 7 and 8 are provided with multiple layers of different materials depending on the characteristics with respect to the radiation to be shielded, and the radiation gradually attenuates from the front end portion to the rear end portion of the protective case 1. In the protective case 1, a γ-ray detector 9 and a neutron beam detector 10 are incorporated, and radiation attenuated by the shields 7 and 8 is monitored.

  The lead wires connected to the cameras 2 and 3 are connected to the connector 11 provided at the rear end of the protective case 1 while avoiding the streaming phenomenon of radiation by being wired spirally inside the protective case 1. It is connected. Further, the cameras 2 and 3 are connected to the cable wiring 14 via the connector 12 connected to the connector 11, and the video signal captured by the cameras 2 and 3 is connected to the monitoring recording device (not shown) by the cable wiring 14. Sent and stored.

  In such a conventional camera device for monitoring in a radiation environment, the cameras 2 and 3 that use an analog imaging tube having high resistance to radiation are used, and a lens with a narrow viewing angle is attached accordingly. It has been. For the purpose of shooting a wider range with a lens having a narrow viewing angle, at present, two or more cameras 2 and 3 are installed in different directions for shooting.

  However, in the conventional camera device using the cameras 2 and 3 using a lens with a narrow viewing angle, for example, as shown in FIG. 6, a plurality of cameras having different directions with respect to an area s requiring monitoring. Even if you shoot with 2 or 3, there is a limit to the field of view that can be covered. In addition, since the image pickup tube is an analog type, the resolution of the photographed image is low and color photography cannot be performed, so that it is difficult to distinguish a fine image. The captured video signal is transmitted through an output cable through a shield of the apparatus, but there is a possibility that a radiation leakage phenomenon may occur in the vicinity of a pipe or the like due to a streaming phenomenon of radiation.

  Moreover, since the cameras 2 and 3 to be used are special structures with radiation resistance, an expensive camera is required. Nevertheless, since the cameras 2 and 3 are always installed in a high-level radiation environment, the radioactive deterioration has progressed, and the camera needs to be replaced and repaired at a regular inspection once a year. However, since the cameras 2 and 3 are attached to the portions ahead of the shields 7 and 8 in the protective case 1, it is extremely difficult to replace the cameras 2 and 3 without exposure to radiation.

JP 2008-76370 A JP 2003-163941 A JP 2003-131136 A Japanese Patent Laid-Open No. 11-191855

  The present invention can suppress radiation deterioration of a camera in view of the problems in the conventional camera device for monitoring in a radiation environment in which a camera using an imaging tube as described above is arranged at the tip of a protective case. Can use a solid-state image sensor such as a CCD image sensor (Charge Coupled Device Image Sensor) or a CMOS image sensor (Complementary Metal Oxide Semiconductor Image Sensor), and use a lens with a wide viewing angle as a lens. In this way, a wide area can be photographed.

  In the present invention, in order to achieve the above object, only the lens 15 is disposed in front of the shields 7 and 8 in the protective case 1 embedded through the radiation shielding wall 30, and the camera 17 has the same protective case. 1 is arranged behind the shields 7 and 8 in 1. The lens 15 and the camera 17 were optically connected via the relay lens 16. Thereby, radiation deterioration of the camera 17 can be suppressed, a solid-state image sensor such as a CCD image sensor or a CMOS image sensor can be used as the image sensor of the camera 17, and a lens with a wide viewing angle can be used as the lens 15. It was.

  That is, the camera device for monitoring in a radiation environment according to the present invention includes a lens 15, a camera 17 that captures an image through the lens 15, and a lens 15 that connects the image through the lens 15 to the imaging elements of the cameras 17 and 18. It has a long relay lens 16 that optically connects the image sensor of the camera 17.

Furthermore, using such a camera device for monitoring in a radiation environment, this is housed in a protective case 1 installed so as to penetrate the radiation shielding wall 30, and is shielded by radiation resistant glass 5 that blocks radiation and transmits light. A lens 15 is arranged toward the imaging area through only the radiation-resistant glass 5 at the tip of the covered protective case 1, and shields 7 and 8 for shielding radiation are provided behind the lens 15 in the protective case 1. The cameras 17 and 18 are mounted on the relay lens 16 via the prism box 19 so that the cameras 17 and 18 are disposed at positions shifted from the optical axis of the relay lens 16 and behind the shields 7 and 8 in the protective case 1. The relay lens 16 is provided so as to penetrate the shields 7 and 8 in the protective case 1.

  As the lens 15, a wide-angle lens with a short focal distance, a shortest shooting distance, a wide viewing angle, and a large depth of field, specifically, a super-wide-angle lens such as a fish-eye lens is used. Thereby, it is possible to photograph a wide range. The light that has entered through the lens 15, which is a wide-angle lens, is refracted and guided backward through the relay lens 16, and optically designed so that the focal point is far behind the focal length of the lens 15. Specifically, it is optically designed so that the image sensor built in the camera 17 is in focus.

  Only the lens 15 is disposed in front of the shields 7 and 8 in the protective case 1, and the relay lens 16 is provided so as to penetrate the shields 7 and 8 in the protective case 1. Since it arrange | positions behind the shields 7 and 8 in the inside, the camera 17 can be arrange | positioned in the area where the radiation was fully attenuated by the shields 7 and 8. Therefore, as the camera 17, a camera using a solid-state image sensor such as a CCD image sensor or a CMOS image sensor can be used.

  The camera 17 can be provided so as to be directly optically connected to the rear end side of the relay lens 16, but is preferably disposed at a position shifted from the optical axis of the relay lens 16 via the prism box 19. By doing so, the camera 17 can be disposed at a position shielded by the shields 7 and 8 from the front end side of the protective case 1, and the influence of the radiation on the camera 17 can be further reduced.

  In addition to directly attaching the camera 17 to the prism box 19, the camera 17 can be attached via a zoom adapter 20 that can change the photographing magnification. Thereby, images with different magnifications can be taken by the camera 17. For example, a wide range can be photographed as a whole or a narrow range can be enlarged.

  In addition, a mount 26 is provided in the prism box 19 via a slide mechanism 24 that can move in the XY direction (two-dimensional direction), and the optical axis of the camera 17 is relative to the optical axis of the relay lens 16 or the prism box 19. It can also be provided so that it can move. This makes it possible to change the shooting position when shooting in a narrow range.

  In addition to providing only one camera 17, 18 in the prism box 19, a prism prism is built in the prism box 19, and a plurality of cameras 17, 18 can be attached to the prism box 19 so that the split light enters the plurality of cameras 17, 18. I can do it. Thereby, for example, the entire image that can be photographed by the lens 15 and a part of the enlarged image can be simultaneously viewed by the separate cameras 17 and 18.

As described above, in the camera device for monitoring under a radiation environment according to the present invention, the radiation reaching the lens 15 can be blocked by the radiation resistant glass 5 that blocks radiation. On the other hand, by placing the camera 17 in an environment where the influence of radiation is small with the shields 7 and 8, a camera 17 using a solid-state imaging device such as a CCD image sensor or a CMOS image sensor can be used. High color images can be obtained.

  Since the camera 17 side can be placed in an environment where the influence of radiation is small, replacement of the camera 17, addition of the number of cameras 17, and use of attachments such as a zoom adapter 20 and an XY movable mount 26 associated therewith Therefore, it is possible to cope with shooting for various purposes. In particular, since the focal length is short as the lens 15, a wide range can be photographed by using a wide-angle lens having a short photographing minimum distance, a wide viewing angle, and a deep depth of field. In addition, by using the above-described attachment, it is possible to arbitrarily enlarge a part of a photographing part in a wide photographing area and move the photographing part.

It is a vertical side view which shows one Example of the camera apparatus for monitoring in a radiation environment. It is the side view which abbreviate | omitted one part of the relay lens, and partially showed the part of the prism box in one Example of the optical part of the camera apparatus for monitoring in a radiation environment. It is a schematic perspective view which shows typically the imaging | photography area in one Example of the camera apparatus for monitoring in a radiation environment. It is the perspective view which abbreviate | omitted and showed the other Example of the optical part of the camera apparatus for monitoring in a radiation environment from a part of relay lens. It is a vertical side view which shows the prior art example of the camera apparatus for monitoring in a radiation environment. It is a schematic perspective view which shows typically the imaging | photography area in the prior art example of the camera apparatus for monitoring in a radiation environment.

In the present invention, in order to achieve the above object, only the lens 15 is arranged in front of the shields 7 and 8 in the protective case 1, and the camera 17 is located behind the shields 7 and 8 in the protective case 1. The lens 15 and the camera 17 were optically connected via the relay lens 16.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  FIG. 1 shows an embodiment of a camera device for monitoring under a radiation environment of the present invention. The optical part of the camera device for monitoring in a radiation environment is a cylinder provided through a radiation shielding wall 30 for partitioning a space in the radiation environment, as in the conventional camera device for monitoring in a radiation environment described above with reference to FIG. It is incorporated in a protective case 1 of the shape. Portions in common with the conventional camera device for monitoring in a radiation environment described above with reference to FIG.

In the same manner as the conventional camera device for monitoring in a radiation environment described above with reference to FIG. 5, a space in a radioactive environment such as a warehouse in which high-level radioactive waste or the like is stored is partitioned by a radiation shielding wall 30. A cylindrical protective case 1 is embedded so as to penetrate the shielding wall 30.
The front end surface of the protective case 1 is covered with a radiation resistant glass 5 attached with a mounting bolt 6. The radiation resistant glass 5 is a transparent glass plate that blocks radiation and transmits light. A lens 15 as a wide-angle lens, more specifically, a fisheye lens, which is a super-wide-angle lens, is disposed at the tip of the protective case 1 covered with the radiation-resistant glass 5. The lens 15 is provided toward the imaging area only through the radiation resistant glass 5.

  Shields 7 and 8 are provided behind the lens 15 in the protective case 1 to shield the radiation, and are blocked so that the radiation does not reach the rear part of the protective case 1. . The shields 7 and 8 are provided with multiple layers of different materials depending on the characteristics with respect to the radiation to be shielded, and the radiation gradually attenuates from the front end portion to the rear end portion of the protective case 1. In the protective case 1, a γ-ray detector 9 and a neutron beam detector 10 are built in, and radiation in the protective case 1 is monitored. Among these, in particular, the neutron beam detector 10 is disposed in an area ahead of the shields 7 and 8 of the protective case 1 in the environment where the influence of radiation on which the lens 15 is disposed is large. The line level can be measured.

  The lens 15 is provided at the tip of a relay lens 16 in which a plurality of lenses and a plurality of groups of lenses are housed in a long cylindrical body. The long relay lens 16 penetrates the shields 7 and 8, and the rear end of the relay lens 16 is disposed on the rear end side of the protective case 1. The rear end of the protective case 1 where the rear end of the relay lens 16 is disposed is an area where the radiation on the front end side of the protective case 1 is shielded by the shields 7 and 8 and the influence of the radiation is small.

  A camera 17 is attached to the rear end of the relay lens 16 arranged in an area where the influence of the radiation is small. The light incident through the lens 15, which is a wide-angle lens, is refracted and guided backward through the relay lens 16, and optically designed so that the focal point is far behind the focal length of the lens 15. Specifically, it is optically designed so that the image sensor built in the camera 17 is in focus.

  Although the camera 17 can be provided so as to be directly optically connected to the rear end side of the relay lens 16, the camera 17 is disposed at a position shifted from the optical axis of the relay lens 16 via an attachment such as a prism box 19. By doing so, the camera 17 can be disposed at a position shielded by the shields 7 and 8 from the front end side of the protective case 1, and the influence of the radiation on the camera 17 can be further reduced.

  The lead wire connected to the camera 17 is connected to a connector 11 provided at the rear end of the protective case 1. Further, the camera 17 is connected to the cable wiring 14 through the connector 12 connected to the connector 11, and the video signal captured by the camera 17 is transmitted to the monitoring recording device (not shown) via the cable wiring 14 and stored. Is done.

  FIG. 2 shows an optical system from the lens 15 shown in FIG. 1 to the camera 17 via the relay lens 16. It is a figure of the state taken out from the protective case. In this example, the camera 17 is shown attached to the rear end side of the relay lens 16 via a prism box 19 as an attachment. Further, a zoom adapter 20 is inserted between the prism box 19 and the camera 17 as an attachment. Thereby, images with different magnifications can be taken by the camera 17. For example, a wide range can be photographed as a whole or a narrow range can be enlarged.

  As shown in FIG. 2, the cylinder of the relay lens 16 is a multiple cylinder, one of which is fixed to the fixed ring of the lens 15 and the other one is fixed to the movable ring for adjusting the focal length of the lens 15. Has been. The cylinder fixed to the movable ring is connected to a focus adjusting screw 23 provided on the back surface of the prism box 19 through a rotation mechanism built in the prism box 19. By rotating the focus adjusting screw 23, the movable ring for adjusting the focal length of the lens 15 is rotated, and focusing can be performed.

  Further, the prism box 19 is provided with a mount 26 via a slide mechanism 24 that can move in the XY direction (two-dimensional direction), and a camera 17 or a zoom adapter 20 as an attachment is attached to the mount 26. The slide mechanism 24 rotates the X-direction adjusting screw 21 to move the mount 26 in the front-rear direction in FIG. 2, so that the optical axis of the camera 17 is relative to the optical axis of the relay lens 16 or the prism box 19. It can move in the X direction, that is, the front-rear direction in FIG. Further, by rotating the Y direction adjusting screw 22 of the slide mechanism 24, the mount 26 is moved in the vertical direction in FIG. 2, and the optical axis of the camera 17 is set in the Y direction with respect to the optical axis of the relay lens 16 or the prism box 19. That is, it can move in the vertical direction in FIG. This makes it possible to change the shooting position when shooting in a narrow range.

  FIG. 3 schematically shows an imaging area of the camera device for monitoring in a radiation environment. Area A is the maximum shooting area when the magnification of the zoom adapter 20 is minimized. By using a wide-angle lens, particularly a fish-eye lens, which is a super-wide-angle lens, as the lens 15, this shootable maximum area A can ensure a considerable range. Area B is the minimum shooting area when the magnification of the zoom adapter 20 is maximized. As described above, by enlarging the magnification of the zoom adapter 20, it is possible to magnify and capture a specific portion in the shootable maximum area A. Then, by rotating the X direction adjusting screw 21 and the Y direction adjusting screw 22 to move the optical axis of the mount 26, that is, the camera 17 attached thereto, the position of the area B is moved in the XY direction. I can do it. That is, it is possible to take a picture while moving the position of the area B in which a specific part in the area A is enlarged.

  In addition to providing only one camera 17 in the prism box 19, as shown in FIG. 4, as shown in FIG. 4, the prism box 19 has a built-in spectroscopic prism so that the split light enters the plural cameras 17 and 18. Multiple can be attached to. In particular, in the embodiment shown in FIG. 4, the cameras 17 and 18 are mounted on the mount 26 (see FIG. 2) of the prism box 19 via the zoom adapters 20 and 20 that can change the photographing magnification, respectively. Further, the mount 26 on which the zoom adapters 20 and 20 are mounted is mounted on the slide mechanism 24 (see FIG. 2) that is movable in the XY direction described above and includes the X-direction adjusting screw 21 and the Y-direction adjusting screw 22.

  Thus, for example, one camera 17 can capture a wide range of images that can be captured by the lens 15, and the other camera 18 can capture an enlarged image of any part of the range. Of course, the shooting position of the latter enlarged image can be arbitrarily changed by moving the optical axes of the cameras 17 and 18 in the XY directions by the slide mechanism 24.

  The present invention is for the purpose of monitoring operating conditions and security of stored items in a radiation environment where people cannot enter without protective clothing, such as inside a building equipped with a nuclear reactor or inside a warehouse storing radioactive waste. It can be used as a camera device for monitoring.

DESCRIPTION OF SYMBOLS 1 Protective case 7 Shield 8 Shield 15 Lens 16 Relay lens 17 Camera 18 Camera 19 Prism box 20 Zoom adapter 24 Slide mechanism 30 Radiation shielding wall

Claims (3)

A camera device used to monitor a space in a radiation environment from the outside, which is a lens (15) serving as an objective lens for an object to be monitored, and two cameras (17) that capture an image through the lens (15) ), (18) and the imaging device of the cameras (17) , (18) are optically coupled to the imaging device of the cameras (17) , (18) through the lens (15). A long relay lens (16) connected to the inside of a protective case (1) installed so as to penetrate a radiation shielding wall (30) that shields between a space in a radiation environment and the outside thereof A lens (15) is placed through the radiation-resistant glass (5) only at the tip of the protective case (1) covered with radiation-resistant glass (5) that shields radiation and transmits light. Protective cable Shields (7) and (8) for shielding radiation are provided behind the lens (15) in the lens (1), and the cameras (17) and (18) are connected to the relay lens (19) via the prism box (19). 16), the relay lens (16) is disposed at a position deviated from the optical axis, and is disposed behind the shields (7) and (8) in the protective case (1). A camera device for monitoring in a radiation environment, characterized in that a lens (16) is provided so as to penetrate the shielding bodies (7) and (8) in a protective case (1). The radiation environment monitoring according to claim 1, wherein the cameras (17) and (18) are mounted on the prism box (19) via a zoom adapter (20) capable of changing a photographing magnification, respectively. Camera device. A mount (26) is provided on the prism box (19) via a slide mechanism (24) movable in the XY direction (two-dimensional direction), and the cameras (17) and (18) are mounted on the mount. The camera device for monitoring in a radiation environment according to claim 1 or 2.

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