JP2000321394A - Radiation proof camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation proof camera dispensing with a camera case by structuring the camera itself as waterproof, and increasing the life of the entire camera by protecting a CCD from fast neutron. SOLUTION: A CCD 130 is shielded with a front cover side fast neutron shield material 101a at the front, a camera side fast neutron shield material 107a at the rear, lens case side fast neutron shield materials 102a to 102d, and body case side fast neutron shield materials 104a to 104d on the sides. This constitution eliminates fast neutron from directly irradiating on the CCD 130, thereby increasing the life of the CCD 130.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation resistant camera, and more particularly to a radiation resistant camera having improved heat resistance, radiation resistance, and maintainability.

[0002]

2. Description of the Related Art FIG. 7 shows, for example, Japanese Patent Application No. 9-357315.
FIG. 8 is an exploded perspective view of the radiation resistant camera described in FIG. In the figure, reference numeral 1 denotes a radiation hardened camera;
Is the upper cover, 11 is the upper thumbscrew, 12 is the handle,
Reference numeral 13 denotes an upper shielding case made of lead or the like for shielding γ-rays, and 14 denotes an insertion hole through which the upper thumb screw 11 is inserted. Reference numeral 20 denotes a front panel, reference numeral 21 denotes a solid-state imaging device (hereinafter abbreviated as CCD), reference numeral 22 denotes a focus adjustment ring, reference numeral 23 denotes a lens mounting portion for mounting a lens (not shown), and reference numeral 24 denotes the front panel 20. This is a front mounting screw to be mounted on the frame 50.

[0003] Also, 30 is a rear panel, 31 is a rear thumbscrew, 32 is a connector, 40 is a lower cover, 41 is a screw hole to be screwed with the upper thumbscrew 11, and 42 is a gamma ray composed of lead or the like. This is a lower shielding case that shields the frame, and is provided with a frame passage recess 43, a front cable passage recess 44, a rear cable passage recess 45, and a side shield recess 46. Reference numeral 50 denotes a frame; 60, a board on which electronic components are mounted; 61, a front cable connected to the CCD 21;
Is a rear cable connected to the connector 32, 70 is a heat dissipation sheet made of, for example, silicon or the like, 80 is a copper plate, 81
Denotes a board mounting screw.

Next, the assembling operation of the radiation resistant camera 1 will be described. First, the substrate 60, the heat radiation sheet 70 and the copper plate 80
Is mounted on the frame 50 with the board mounting screws 81. In this case, the substrate 60, the heat radiation sheet 70, and the copper plate 80 are bonded to each other. Next, the front panel 20 is attached to the front mounting screw 24.
To the frame 50. Next, the rear panel 3
0 is attached to the frame 50 by the rear thumbscrew 31. Next, the front cable 61 is connected to the CCD 21.
Next, the rear cable 62 is connected to the connector 32 provided on the rear panel 30.

Next, a front panel 20, a rear panel 30,
The frame 50 to which the substrate 60, the heat dissipation sheet 70, and the copper plate 80 are attached is disposed on the lower cover 40. In this case, the frame 50 is recessed through the frame 43, the front cable 61 is recessed through the front cable 44, and the rear cable 62 is recessed.
Is arranged in the rear cable recess 45 and the substrate 60
Into the side shielding recess 46. Next, the upper cover 1
The upper cover 10 and the lower cover 40 are fixed together with the upper thumb screw 11 while the lower cover 40 is joined to the lower cover 40, and the assembling operation is completed.

With the above configuration, the radiation resistant camera 1 shown in FIG. 7 has the following effects. (1) When assembling the radiation-resistant camera 1, the substrate 60 is dropped into the side shielding recess 45 of the lower shielding case 42, so that the entire side surface of the substrate 60 is covered by the lower shielding case 42. The upper part of the substrate 60 is covered by the upper shielding case 13, and the lower part of the substrate 60 is covered by the lower shielding case 42. As a result, even if the radiation resistant camera 1 is moved up, down, left, and right by a camera platform (not shown), γ-rays do not directly irradiate the substrate 60, and electronic components mounted on the substrate 60 are damaged by γ-rays. , The life of the radiation resistant camera 1 as a whole is improved.

(2) The maintenance work of the radiation resistant camera 1 according to the present invention is performed by a frame 50 (hereinafter, abbreviated as an assembled frame) to which the front panel 20, the rear panel 30, the substrate 60, the heat radiating sheet 70, and the copper plate 80 are attached in advance. ) Is exchanged. In other words, at the place where the radiation resistant camera 1 is installed, the maintenance worker can turn the upper thumb screw 11 by hand to remove the upper cover 10 and replace the assembled frame, thereby completing the maintenance work, thereby shortening the work time. Further, the maintenance work is facilitated without requiring any tools for the maintenance work. Incidentally, the weight of the assembled frame is about 1 kg, so that much labor is not required for transportation. Also, the substrate 6
0, since the heat dissipation sheet 70 and the copper plate 80 are arranged below the frame 50, the structure becomes easier to assemble.

(3) The CCD 21 can withstand about three times as much gamma-ray exposure as the electronic components mounted on the substrate 60. In addition, since the assembled frame including the CCD 21 and the substrate 60 is replaced at the time of maintenance, the life of the CCD 21 may be substantially the same as that of the substrate 60. Focusing on this point, the radiation resistant camera 1 according to the present invention adjusts the thickness of the upper shielding case 13 and the lower shielding case 42 so that the degree of deterioration of electronic components mounted on the substrate 60 due to gamma rays is the same as that of the CCD 21. Set to. Thereby, the thickness of the upper shielding case 13 and the lower shielding case 42 does not need to be unnecessarily large, so that the entire radiation-resistant camera 1 can be reduced in size.

[0009]

The conventional radiation hardened camera has the above configuration, and has the following problems. (1) Generally, a radiation-resistant camera is installed in a place where water is sprayed by a sprinkler (not shown) or the like when an accident occurs. Therefore, when installing the radiation resistant camera 1 shown in FIG. 7, it is necessary to store the radiation resistant camera 1 in a waterproof camera case (not shown). For this reason, an installation space for the camera case is required, and there has been a problem that even if the radiation resistant camera 1 itself is reduced in size, the overall size cannot be reduced.

(2) When performing maintenance work on the radiation-resistant camera 1 stored in the camera case, the radiation-proof camera 1 must be removed from the camera case, so that the overall maintenance work is not easy. There were challenges.

(3) When the radiation resistant camera 1 shown in FIG. 7 is installed in an area where high-speed neutrons are irradiated, the substrate 60
There is a problem that the life of the CCD 21 is shorter than the life of the CCD 21. The reason is that the pixels (not shown) of the CCD 21 are damaged by fast neutrons, and the output image is difficult to see. The substrate 60 is not easily damaged by fast neutrons.

A first object of the present invention is to provide a radiation-tolerant camera which does not require a camera case by making the camera itself a waterproof structure. It is. A second object of the present invention is to provide a radiation-tolerant camera in which the CCD is protected from fast neutrons and the life of the entire camera is improved.

[0013]

According to the present invention, there is provided a radiation resistant camera comprising: a CCD substrate on which a CCD is mounted;
A lens disposed in front of the D substrate, a cylindrical lens case surrounding the lens, a lens case side high-speed neutron shielding material provided around the lens case, and a lens disposed on the front of the lens case; A front cover joined to a case, a front cover-side high-speed neutron shielding material provided opposite to the CCD substrate of the front cover, and the CC
A camera unit having a substrate including an electronic component connected to the D substrate, a cylindrical main body case covering the camera unit and joining to the lens case, and provided integrally with the camera unit and joined to the body case. A rear cover, a body case-side high-speed neutron shielding material provided around the inside of the body case facing the CCD substrate, and a camera unit-side high-speed neutron shielding material provided behind the CCD board of the camera unit It is provided with.

Further, the radiation-tolerant camera according to the following invention is characterized in that the high-speed neutron shielding material on the lens case side, the high-speed neutron shielding material on the front cover, the high-speed neutron shielding material on the main body case, and the high-speed neutron shielding material on the camera unit side have a high hydrogen atom density. Using a member having a high height.

In the radiation resistant camera according to the next invention, the thickness of the high-speed neutron shielding material on the lens case side, the high-speed neutron shielding material on the front cover side, the high-speed neutron shielding material on the main body case, and the thickness of the high-speed neutron shielding material on the camera unit side are reduced. Fast neutrons are CCD
Is set according to the angle of incidence on the surface.

In the radiation-tolerant camera according to the next invention, the thickness of the high-speed neutron shielding material on the front cover side and the thickness of the high-speed neutron shielding material on the camera unit side are reduced to a thickness that reduces the incident high-speed neutron dose by half.

In the radiation resistant camera according to the next invention, a member that transmits light is used as the high-speed neutron shielding material on the front cover side.

In the radiation resistant camera according to the next invention, the lens case and the front cover are joined by a catch clip.

In the radiation resistant camera according to the next invention, the main body case and the rear cover are joined by a catch clip.

Further, in the radiation resistant camera according to the next invention, a waterproof packing is arranged between the front cover and the lens case, between the lens case and the main body case, and between the main body case and the rear cover. Things.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a radiation hardened camera according to the present invention. FIG. 1A is a side view, FIG. 1B is a front view, and FIG. 1C is a rear view.
FIG. 2 is an exploded perspective view of the radiation resistant camera shown in FIG. In the figure, reference numeral 100 denotes a radiation hardened camera,
01 is a front cover, 101a is a front cover-side high-speed neutron shielding material (hereinafter, abbreviated as a cover-side neutron shielding material), 102
Is a lens case.

Reference numerals 102a to 102d denote high-speed neutron shielding materials on the lens case side (hereinafter abbreviated as lens-side neutron shielding materials), 103 a cover-side catch clip, 103a a cover-side catch clip receiver, 104 a main body case,
105 is a main body side catch clip, 105a is a main body side catch clip receiver, 106 is a lens, 107 is a camera unit, 108 is a camera control connector, 109 is a video signal output connector, 110 is a handle, and 111 is a camera unit 10.
7 is a rear cover attached to the rear cover 7.

FIG. 3 is a cross-sectional view of the radiation resistant camera shown in FIG. 1, FIG. 4 is a view taken along the line AA of FIG. 3, and FIG.
FIG. In the figure, reference numerals 104a to 104d denote a main body case side high-speed neutron shielding material (hereinafter abbreviated as a main body side neutron shielding material), 107a denotes a camera part side high speed neutron shielding material (hereinafter abbreviated as a camera part side neutron shielding material) 120a. γ-ray shielding material, 120b is a rear γ-ray shielding material, 121a is an upper γ-ray shielding material, 121b is a lower γ-ray shielding material, 122 is a space portion, 123a is an upper shielding material support frame, 123b
Is a lower shield supporting frame.

Reference numeral 130 denotes a CCD, 131 denotes a CCD board, 132 denotes a first cable, 133 denotes a board, and 134 denotes a second cable. Further, 140 to 142 are waterproof packings, 143 is a support stand, and 144 is a guide rail.
The heat radiation sheet 70 and the copper plate 80 shown in FIG. 8 are inserted between the front γ-ray shielding member 120a and the substrate 133 to improve the heat radiation efficiency. The CCD substrate 131 has a CCD 130 that is susceptible to fast neutrons, and the substrate 133 has electronic components (not shown) that are susceptible to γ-rays.

The cover-side neutron shielding member 101a, the lens-side neutron shielding members 102a to 102d, the body-side neutron shielding members 104a to 104d, and the camera-unit-side neutron shielding member 107a are made of acrylic having a high hydrogen atom density and transmitting light. Are used to enable imaging by the CCD 130. FIG. 6 is an explanatory diagram showing the shielding characteristics of acrylic against fast neutrons. The horizontal axis indicates the acrylic thickness, and the vertical axis indicates the fast neutron dose.

High-density lead is used for the front γ-ray shielding material 120a, the rear γ-ray shielding material 120b, the upper γ-ray shielding material 121a, and the lower γ-ray shielding material 121b. Also,
The first cable 132 connects the CCD board 131 and the board 133, and the second cable 134 connects the board 133 to the camera control connector 108 or the video signal output connector 109.
And connect.

Next, the assembling operation of the radiation resistant camera 100 shown in FIG. 1 will be described. First, the lens case 102 to which the lens-side neutron shielding members 102a to 102d are attached in advance, and the body-side neutron shielding members 104a to 104
d, upper γ-ray shielding material 121a, lower γ-ray shielding material 121b
And body case 1 to which guide rail 144 is attached
04 are joined by inserting a waterproof packing 141 between them and screwing them.

Next, the cover-side neutron shielding material 101a
Front cover 101 with lens attached and lens case 10
2 are joined by the catch clip 103 on the cover side with the waterproof packing 140 inserted therebetween. Next, the modularized camera unit 107 and the rear cover 111 are joined by screws or the like, and the rear cover 111 and the main body case 104 are further joined by inserting the waterproof packing 142 therebetween and the main body side catch clip 105. To complete the assembling operation.

With the above configuration, the radiation resistant camera 100 shown in FIG. 1 has the following effects. (1) Cover-side neutron shielding material 101a, lens-side neutron shielding materials 102a to 102d, body-side neutron shielding material 104
a to 104d, the camera unit side neutron shielding material 107a shields the CCD 130 from high-speed neutrons.
The life of D130 is improved. Here, the shielding characteristics of acrylic against fast neutrons shown in FIG.
The thickness of the neutron shielding material was determined in consideration of the design dimension of 00 and the direction of incidence of the fast neutrons on the CCD 130.

According to FIG. 6, the thickness required for halving the fast neutron dose is 30 to 50 mm. If the fast neutron dose can be reduced by half, the damage rate of CCD pixels will be reduced by half.
Thereby, the thickness of the cover-side neutron shielding material 101a and the camera-side neutron shielding material 107a facing the CCD 130 was set to 40 mm, and the thickness of the main body-side neutron shielding materials 104a to 104d orthogonal to the CCD 130 was set to 30 mm. .

The thickness of the lens-side neutron shielding members 102a to 102d which are inclined with respect to the CCD 130 is as follows.
The thickness was set to 20 mm in consideration of an increase in the thickness of fast neutrons when the neutrons were incident in the CCD direction. Accordingly, the thickness of the lens-side neutron shielding members 102a to 102d can be reduced, so that the entire radiation-resistant camera 100 can be reduced in size and weight.

(2) By making the substrate 133 inserted into the camera unit 107 perpendicular to the camera unit 107, the depth of the camera unit 107 can be shortened, and the whole radiation resistant camera 100 can be reduced in size. Can be. Further, the ends of the upper γ-ray shielding material 121a and the lower γ-ray shielding material 121b were deleted as shown in FIG. Accordingly, the upper γ-ray shielding member 121a and the lower γ-ray shielding member 121b become lighter, and the entire radiation-resistant camera 100 can be reduced in weight.

(3) As shown in (1) and (2), a shielding material for high-speed neutrons is used for the CCD 130, and a shielding material corresponding to a γ-ray is used for the substrate 133. By arranging them individually, the radiation hardened camera 100 as a whole is made thinner. Note that the lens-side neutron shielding materials 102a to 102a
2d, the body-side neutron shielding members 104a to 104d and the camera-side neutron shielding member 107a may be a polymer material such as polycarbonate or water as long as they have a high hydrogen atom density capable of shielding fast neutrons, and may transmit light. It doesn't matter what you do.

(4) Front cover 101 and lens case 1
02, between the lens case 102 and the body case 104, and between the body case 104 and the rear cover 111, waterproof packings 140 to 142 are provided to make the radiation-resistant camera 100 itself waterproof. As a result, it is not necessary to separately provide a camera case (not shown) for waterproofing, so that the installation space can be reduced, and it is not necessary to take out the camera from the camera case as in the conventional example. The performance is improved.

(5) The front cover 101 and the lens case 102 are joined by a catch clip 103 on the cover side. Also, the main body case 104 and the rear cover 111
And are joined by a main body side catch clip 105. For this reason, the front cover 101 and the rear cover 111 can be easily removed from the main body case 104 without tools, thereby improving maintainability. Further, for example, the maintenance work at the installation location of the radiation resistant camera 100 is performed by the rear cover 111.
Replacement of the camera unit 107 including the
If only the replacement is performed, the maintenance work time of the worker (not shown) at the installation location of the radiation resistant camera 100 can be reduced.

(6) Lens case 102 and main body case 1
It is provided separately from 04 and is joined by screwing. This is because the dimensions of the lens 106 used differ depending on the imaging conditions, and it is necessary to attach the lens case 102 that matches the dimensions of the lens 106. Thus, the lens case 102 that matches the lens 106 can be selected, and the versatility is improved.

(7) As can be seen from FIG. 3, the lens case 102 and the main body case 104 are vertically symmetric. Further, the guide rail 144 can be attached to the upper side. Thereby, the guide rail 144 is attached to the upper shielding member support frame 123a side, and the camera unit 10
7 is inserted upside down, the support base 143 faces upward. Accordingly, even if the support 143 is not provided on the upper shielding material support frame 123a side, the radiation resistant camera 100
Can be fixed on the upper side.

(8) Generally, the installation location of the radiation resistant camera 100 is a dangerous area, and it is not allowed to take out foreign substances from the radiation resistant camera 100 itself at the installation location. Also, for example, when the surface of the main body case 104 is painted and the paint comes off, the paint is also regarded as a foreign substance. For this reason, the front cover 101, the lens case 102, the main body case 104, and the frames used for the camera section 107 are made of a stainless steel that is resistant to rust, and are not coated. Accordingly, the radiation resistant camera 100 can be installed at the installation location.
Safety is improved because no foreign matter comes out of itself.

[0039]

According to the present invention, the radiation hardened camera
A CCD substrate mounted with a CCD, a lens disposed in front of the CCD substrate, a cylindrical lens case covering the lens, a lens case side high-speed neutron shielding material provided around the lens case, An electronic component in which a front cover disposed on the front of the case is joined to the lens case, a front cover-side high-speed neutron shielding material is provided to face the CCD substrate of the front cover, and a camera unit is connected to the CCD substrate. And a cylindrical main body case covers the camera section and is joined to the lens case.A rear cover integrally provided with the camera section is joined to the main body case, and the main body case side high speed is provided. A neutron shielding material is provided around the inside of the main body case opposite to the CCD substrate, and a camera-side high-speed neutron shielding material is provided behind the CCD substrate of the camera unit. Because provided, the lens case side fast neutron shielding material, the front cover side fast neutron shielding material,
Since the main body case side fast neutron shielding material and the camera unit side fast neutron shielding material surround the CCD and shield the fast neutrons, the life of the CCD is improved.

According to the next invention, the radiation-tolerant camera comprises a high-speed neutron shielding material on the lens case side, a high-speed neutron shielding material on the front cover, a high-speed neutron shielding material on the main body case, and a high-speed neutron shielding material on the camera unit side. Since a member having a high atomic density is used, there is an effect that neutrons can be reliably shielded.

According to the next invention, the radiation-tolerant camera has a thickness of the high-speed neutron shielding material on the lens case side, the high-speed neutron shielding material on the front cover side, the high-speed neutron shielding material on the main body case, and the high-speed neutron shielding material on the camera unit side. The fast neutron is CCD
Is set in accordance with the angle of incidence on the surface of the device, so that the thickness of the shielding member does not need to be increased unnecessarily, and the size of the entire device can be reduced.

According to the next invention, in the radiation resistant camera, the thickness of the front cover side high-speed neutron shielding material and the camera unit side high-speed neutron shielding material is set to a thickness that reduces the incident high-speed neutron dose by half. Since the fast neutron dose applied to the CCD is halved, the damage rate of the CCD pixels is halved,
D has an effect of improving the life.

According to the next invention, since the radiation-tolerant camera uses a member that transmits light as the high-speed neutron shielding material on the front cover side, there is an effect that imaging by a CCD becomes possible.

Further, according to the invention, since the lens case and the front cover are joined by the catch clip in the radiation resistant camera, the front cover can be replaced without using a tool, thereby improving the maintainability. There is.

Further, according to the next invention, in the radiation resistant camera, since the main body case and the rear cover are joined by the catch clip, the rear cover and the camera unit integrated with the rear cover can be replaced without using a tool. This has the effect of improving maintainability.

Further, according to the next invention, the radiation resistant camera is provided with a waterproof packing between the front cover and the lens case, between the lens case and the main body case, and between the main body case and the rear cover. The arrangement has an effect that the entire device has a waterproof structure.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a radiation resistant camera according to Embodiment 1 of the present invention, FIG. 1 (a) is a side view, FIG. 1 (b) is a front view, and FIG. 1 (c) is a rear view. .

FIG. 2 is an exploded perspective view of the radiation resistant camera shown in FIG.

FIG. 3 is a sectional view of the radiation hardened camera shown in FIG. 1;

FIG. 4 is a diagram showing an arrow AA in FIG. 3;

FIG. 5 is a view taken along the line BB of FIG. 3;

FIG. 6 is an explanatory diagram showing the shielding properties of acrylic against fast neutrons, in which the horizontal axis indicates the thickness of acrylic and the vertical axis indicates the fast neutron dose.

FIG. 7 is a side view of a conventional radiation hardened camera.

8 is an exploded perspective view of the radiation resistant camera shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 radiation resistant camera 101 front cover 101 a front cover-side high-speed neutron shielding material 102 lens case 102 a to 102 d lens case-side high-speed neutron shielding material 103 cover-side catch clip 103 a cover-side catch clip receiver 104 main body case 104 a to 104 d main body case-side high-speed neutron Shielding material 105 Body side catch clip 105a Body side catch clip receiver 106 Lens 107 Camera unit 107a Camera unit side high-speed neutron shielding material 108 Camera control connector 109 Video signal output connector 110 Handle 111 Rear cover 120a Front γ-ray shielding material 120b Rear side γ-ray shielding material 121a Upper γ-ray shielding material 121b Lower γ-ray shielding material 122 Space 123a Upper shielding material supporting frame 123b Lower shielding material supporting frame 130 CD 131 CCD substrate 132 first cable 133 substrate 134 second cable 140-142 waterproof packing 143 support base 144 guide rail

Claims (8)

[Claims] 1. A CCD substrate having a CCD mounted thereon, a lens disposed in front of the CCD substrate, a cylindrical lens case surrounding the lens, and a lens case side high-speed neutron shield provided around the lens case. A front cover disposed on the front surface of the lens case and joined to the lens case; a front cover-side high-speed neutron shielding material provided to face the CCD substrate of the front cover; and a connection to the CCD substrate A camera unit having a substrate including electronic components to be formed, a cylindrical body case covering the camera unit and joining with the lens case, and a rear cover provided integrally with the camera unit and joining with the body case. A body case-side high-speed neutron shielding material provided around the inside of the body case facing the CCD substrate; Radiation-resistant camera comprising the camera unit side high-speed neutron shielding material provided at the rear of the substrate. 2. The high-speed neutron shielding material on the lens case side, the high-speed neutron shielding material on the front cover, the high-speed neutron shielding material on the main body case, and the high-speed neutron shielding material on the camera unit side are made of a member having a high hydrogen atom density. The radiation hardened camera according to claim 1. 3. The thickness of the high-speed neutron shielding material on the lens case side, the high-speed neutron shielding material on the front cover side, the high-speed neutron shielding material on the body case side, and the high-speed neutron shielding material on the camera unit side depend on the angle at which the high-speed neutrons enter the CCD. The radiation hardened camera according to any one of claims 1 to 3, wherein the radiation hardened camera is set. 4. The radiation-tolerant radiation according to claim 3, wherein the thickness of the front cover-side fast neutron shielding material and the camera unit-side fast neutron shielding material is set to a thickness that reduces the incident fast neutron dose by half. camera. 5. The radiation-resistant camera according to claim 1, wherein a member that transmits light is used as the high-speed neutron shielding material on the front cover side. 6. The radiation resistant camera according to claim 1, wherein the lens case and the front cover are joined by a catch clip. 7. The radiation resistant camera according to claim 1, wherein the main body case and the rear cover are joined with a catch clip. 8. A waterproof packing is provided between the front cover and the lens case, between the lens case and the main body case, and between the main body case and the rear cover. A radiation-resistant camera according to any one of claims 7 to 7.