Explosion proof camera

Abstract

To provide an exploration proof camera capable of taking a high quality image.SOLUTION: An explosion proof camera 1 includes: a camera 7 having a light guide part 71 for guiding imaging light to an imaging part located inside; an outer peripheral part arranged on an outer periphery of the light guide part; and an explosion proof container 2 for housing the camera 7 and the outer peripheral part. The explosion proof container 2 includes a light transmittance cover part 41 for covering the light guide part 71 and the outer peripheral part. The outer peripheral part is arranged facing an inner surface of the cover part 41 and has a reflection suppressing color with an L* value of 0 to 60 in the L*a*b* color chart system specified in JIS Z8781-4:2013.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an explosion-proof camera.

Background Art

[0002] As a conventional technique, there is, for example, an explosion-proof camera described in Patent Document 1. This explosion-proof camera includes a television camera, a pan-tilt that supports the television camera and changes its orientation, a glass case that houses the television camera and the pan-tilt to block outside air and is made of transparent tempered glass, and a pedestal provided below the glass case. Note that the television camera has a camera lens.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the explosion-proof camera described in Patent Document 1, shooting is performed through the glass case. Therefore, when the light hitting the television camera or the pan-tilt is reflected from the glass case and enters the camera lens, the television camera or the pan-tilt is reflected in the video captured by the television camera. Therefore, the explosion-proof camera described in Patent Document 1 has a problem that the quality of the captured video is lowered due to the reflection.

[0005] Therefore, an object of the present invention is to provide an explosion-proof camera that can capture images beautifully.

Means for Solving the Problems

[0006] The present invention a camera including a light guide unit that guides imaging light to an imaging unit located inside; an outer peripheral portion disposed on the outer periphery of the light guide unit; An explosion-proof container for housing the camera and the outer peripheral portion, comprising: an explosion-proof container having a light transmissivity and including a cover portion that covers the light guide portion and the outer peripheral portion. The outer peripheral portion is disposed to face the inner surface of the cover portion, and has a reflection suppression color with an L* value of 0 to 60 in the L*a*b* color system defined in JIS Z8781-4:2013. It is an explosion-proof camera characterized by this.

[0007] According to the above configuration, by suppressing the light that enters the explosion-proof container from the cover portion from being reflected from the outer peripheral portion, it is possible to prevent the outer peripheral portion from being reflected in the video captured by the imaging portion.

[0008] In the present invention, The outer peripheral portion may be a covering member that covers the peripheral portion disposed around the light guide portion from the side facing the inner surface of the cover portion.

[0009] According to the above configuration, by covering the peripheral portion with the covering member, it is possible to prevent the peripheral portion from being reflected in the video captured by the imaging portion. Therefore, in an explosion-proof camera unitized to have the peripheral portion, it is possible to prevent the quality of the video from deteriorating due to simple processing.

[0010] Also, in the present invention, The covering member may be configured such that the L* value of the entire area is the same on the surface facing the inner surface of the cover portion.

[0011] According to the above configuration, since the reflectance of light can be made constant over the entire area of the covering member, it is possible to more stably prevent the outer peripheral portion from being reflected in the video captured by the imaging portion.

[0012] Also, in the present invention, The covering member may be constituted by a resin film.

[0013] According to the above configuration, it is easy to match the shape and size of the peripheral part, and it is possible to simply prevent the peripheral part from being reflected in the video captured by the imaging unit.

[0014] Also, in the present invention, the camera may be fixed in orientation with respect to the explosion-proof container and capable of photographing in all directions.

[0015] According to the above configuration, since the camera is fixed in orientation and capable of photographing in all directions, for example, it is possible to photograph in a wide range without providing a mechanism for moving the camera in the pan direction or the tilt direction, and also to reduce the cause that may lead to an explosion inside the explosion-proof container (i.e., the generation of sparks due to the movement of the camera).

[0016] Also, in the present invention, the explosion-proof container includes a cylindrical container body and a lid for closing the container body, the lid includes the cover portion and is configured to be removable with respect to the container body, the camera may be attached to the lid.

[0017] According to the above configuration, even if the lid is removed from the container body, the positional relationship between the camera and the cover portion does not change. Therefore, each time the lid is removed from the container body, the labor of adjusting the optical axis between the camera and the cover portion can be eliminated.

[0018] Also, in the present invention, the container body and the lid may be connected via a hinge.

[0019] According to the above configuration, for example, when performing maintenance inside the explosion-proof camera installed at a high place, it is not necessary for the operator to hold the lid removed from the container body by hand, so the workability can be improved.

Advantages of the Invention

[0020] As described above, according to the present invention, by preventing the outer peripheral portion from being reflected in the video captured by the imaging unit, it is possible to prevent the quality of the video from deteriorating, and thus the video can be captured beautifully.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Embodiments for Carrying Out the Invention

[0022] Hereinafter, an embodiment of the present invention will be described. In the following description, the height direction of the explosion-proof camera 1 is referred to as the "height direction H", and in the "vertical" and "horizontal" defined for convenience, the vertical width direction is referred to as the "vertical direction D", and the horizontal width direction is referred to as the "horizontal direction W". Among the height direction H, the upper side (specifically, the upper side in FIG. 3 and the left side in FIG. 4) is referred to as one side of the height direction H, and the lower side (specifically, the lower side in FIG. 3 and the right side in FIG. 4) is referred to as the other side of the height direction H.

[0023] The explosion-proof camera 1 is an explosion-proof electrical apparatus installed in places where there is an explosive atmosphere such as flammable gas or vapor. The explosion-proof camera 1 of the present embodiment has a structure (i.e., a pressure-resistant explosion-proof structure) that can withstand the increase in pressure when an explosion occurs inside the explosion-proof camera 1 and prevent ignition of the explosive atmosphere outside the explosion-proof camera 1. As shown in FIGS. 1 and 2, the explosion-proof camera 1 includes an explosion-proof container 2 and internal equipment 5.

[0024] The explosion-proof container 2 is for housing the internal equipment 5 described later. The explosion-proof container 2 includes a container body 3 and a lid body 4.

[0025] The container body 3 is a box body having an opening 3a (see FIG. 4) for housing the internal equipment 5. The container body 3 of the present embodiment is a casting formed of metal (specifically, an aluminum alloy). The container body 3 includes a bottom plate 30 extending in the vertical direction D and the horizontal direction W, and a side wall 31 extending from the periphery of the bottom plate 30 to one side in the height direction H. In the present embodiment, the bottom plate 30 is configured in a circular plate shape, and the side wall 31 is configured in a cylindrical shape. Therefore, the container body 3 of the present embodiment is a cylindrical (specifically, a bottomed cylindrical) round box having an opening 3a on one side in the height direction H.

[0026] As shown in FIGS. 1, 3, and 4, a flange portion 310 extending to the outside of the container body 3 is formed on the side wall 31. This flange portion 310 is configured in an annular shape (circular annular shape in the present embodiment). Further, the flange portion 310 is provided on one side (one end in the present embodiment) of the side wall 31 in the height direction H. A plurality of bolt insertion holes (not numbered) for inserting bolts in the height direction H are formed in the flange portion 310 of the present embodiment. The bolt insertion holes are arranged at equal intervals around the height direction H.

[0027] As shown in FIG. 4, one end of the side wall 31 and the flange portion 310 in the height direction H is a flat surface. Incidentally, one end of the side wall 31 and the flange portion 310 in the height direction H is a joint surface when the container body 3 and the lid body 4 are joined. And the total length of the side wall 31 and the flange portion 310 in the inner and outer directions of the explosion-proof container 2 is set to prevent the flame in the explosion-proof container 2 from escaping to the outside and igniting the explosive atmosphere existing outside through the joint surface between the container body 3 and the lid body 4. Note that a waterproof packing 3P is embedded over the entire circumference at one end of the side wall 31 in the height direction H.

[0028] Also, as shown in FIGS. 3 and 4, a cable insertion hole 311 through which a cable connected to the internal device 5 housed in the explosion-proof container 2 is inserted is formed in the side wall 31. This cable insertion hole 311 is configured to be able to insert a cable gland having explosion-proof performance. In the present embodiment, three cable insertion holes 311 are formed in the side wall 31. In FIG. 3, only one cable insertion hole 311 is numbered. The cable insertion hole 311 is disposed on the other side of the flange portion 310 in the height direction H. Further, the cable insertion hole 311 is disposed on the other side (the lower side in FIG. 4) in the vertical direction D.

[0029] As shown in FIG. 1, the lid body 4 is for closing the opening 3a of the container body 3. The lid body 4 includes a lid main body portion 40 in which a through hole 4a (see FIGS. 2 and 4) penetrating in the height direction H is formed, and a cover portion 41 for closing the through hole 4a. Further, as shown in FIG. 4, the lid body 4 of the present embodiment includes a pressing member 42 that presses the cover portion 41 against the lid main body portion 40 from the inside of the explosion-proof container 2, and a packing 43 that closes the gap between the lid main body portion 40, the cover portion 41, and the pressing member 42.

[0030] As shown in FIG. 4, the lid main body 40 of the present embodiment includes a standing wall portion 400, an outer flange portion 401 extending outward from the standing wall portion 400, and an inner flange portion 402 extending inward. The standing wall portion 400 is a member configured in an annular shape. The inner diameter of the standing wall portion 400 is the same as the inner diameter of the container body 3. On the other hand, the standing wall portion 400 is shorter than the side wall 31 in the height direction H. Therefore, the lid 4 of the present embodiment is shorter than the container body 3 in the height direction H. Further, the standing wall portion 400 has the same thickness as the side wall 31 in the direction between the inside and outside of the explosion-proof container 2.

[0031] As shown in FIG. 2, the outer flange portion 401 is configured in an annular shape (specifically, a circular ring shape) extending over the entire circumference of the standing wall portion 400. The outer flange portion 401 is formed at the other end of the standing wall portion 400 in the height direction H. Bolt insertion holes for inserting bolts in the height direction H are arranged at equal intervals around the height direction H in the outer flange portion 401. The outer diameter of the outer flange portion 401 is configured to be substantially the same as the outer diameter of the flange portion 310. Therefore, the inner diameter and the outer diameter of the lid 4 are substantially the same as the inner diameter and the outer diameter of the container body 3, respectively. Here, in the direction between the inside and outside of the explosion-proof container 2, the total length of the standing wall portion 400 and the outer flange portion 401 is the same as the total length of the side wall 31 and the flange portion 310. Therefore, the total length of the standing wall portion 400 and the outer flange portion 401 is set to prevent the flame inside the explosion-proof container 2 from escaping to the outside and igniting the explosive atmosphere existing outside through the joint surface between the container body 3 and the lid 4.

[0032] Further, the other end of the standing wall portion 400 and the outer flange portion 401 in the height direction H is formed as a flat surface. And the other end of the standing wall portion 400 and the outer flange portion 401 in the height direction H is the joint surface when joining the container body 3 and the lid 4. Therefore, one end of the side wall 31 and the flange portion 310 in the height direction H and the other end of the standing wall portion 400 and the outer flange portion 401 in the height direction H are configured to reduce the gap between the joint surfaces when joining the container body 3 and the lid 4 in order to prevent the flame inside the explosion-proof container 2 from escaping to the outside through the gap between the container body 3 and the lid 4.

[0033] The inner flange portion 402 is formed at one end of the vertical wall portion 400 in the height direction H. As shown in FIG. 2, the inner flange portion 402 is configured in an annular shape. Therefore, a through hole 4a is formed in the lid main body portion 40 by the inner flange portion 402. Note that this through hole 4a is a round hole. Further, as shown in FIG. 4, in the inner flange portion 402 of the present embodiment, the inner surface is a tapered surface that inclines radially inward as it advances to one side in the height direction H. Therefore, the through hole 4a is configured such that the length orthogonal to the height direction H is the longest at the other end in the height direction H, and the length orthogonal to the height direction H becomes shorter as it advances to one side in the height direction H.

[0034] The cover portion 41 is made of a translucent material (specifically, glass). The cover portion 41 has a strength capable of withstanding the impact caused by an explosion occurring inside the explosion-proof container 2. For example, the strength of the cover portion 41 is confirmed by a steel ball drop test. The cover portion 41 has a thickness such that it has a strength capable of withstanding the impact caused by an explosion. Therefore, the cover portion 41 is more likely to cause primary reflection and secondary reflection compared to, for example, glass having a thickness that does not have a strength capable of withstanding the impact caused by an explosion. As shown in FIG. 2, the cover portion 41 of the present embodiment is configured in a circular shape when viewed from the front. Further, as shown in FIGS. 3 and 4, the cover portion 41 of the present embodiment is configured in a dome shape. Therefore, the cover portion 41 is configured such that the length orthogonal to the height direction H is the longest at the other end in the height direction H, and the length orthogonal to the height direction H becomes shorter as it advances to one side in the height direction H.

[0035] In the cover portion 41 of the present embodiment, the length orthogonal to the height direction H at one end in the height direction H is shorter than the length orthogonal to the height direction H at the other end in the height direction H of the through hole 4a. Therefore, the cover portion 41 is configured to be insertable into the through hole 4a from the other side in the height direction H. Further, in the cover portion 41 of the present embodiment, the length orthogonal to the height direction H at one end in the height direction H is shorter than the length orthogonal to the height direction H at one end in the height direction H of the through hole 4a, and the length in the height direction H is longer than the length in the height direction H of the inner flange portion 402. And in the cover portion 41 of the present embodiment, the length orthogonal to the height direction H at the other end in the height direction H is longer than the length orthogonal to the height direction H at one end in the height direction H of the through hole 4a. Therefore, as shown in FIGS. 3 and 4, the cover portion 41 of the present embodiment is inserted into the through hole 4a in a state where at least one end in the height direction H is disposed on one side in the height direction H with respect to the lid main body portion 40.

[0036] Further, as shown in FIG. 4, in the present embodiment, in order to ensure the waterproof property between the inner flange portion 402 and the cover portion 41, a packing 4P is provided between the inner surface of the inner flange portion 402 and the cover portion 41. This packing 4P is provided over the entire circumference. Further, the inner surface of the inner flange portion 402 and the cover portion 41 (specifically, the other end in the height direction H) are fixed by an adhesive (not numbered). Note that the inner surface of the inner flange portion 402 and the cover portion 41 are fixed so as to withstand the impact due to the explosion in the explosion-proof container 2.

[0037] As shown in FIG. 4, the pressing member 42 is for pressing and fixing the cover portion 41 inserted into the through hole 4a from the other side in the height direction H. The pressing member 42 of the present embodiment is configured in an annular shape (specifically, a circular ring shape). The inner diameter of the pressing member 42 is smaller than the inner diameter at the other end of the inner flange portion 402 in the height direction H and the outer diameter at the other end of the cover portion 41 in the height direction H. Further, the outer diameter of the pressing member 42 is smaller than the inner diameter of the standing wall portion 400. The pressing member 42 is disposed on the other side in the height direction H with respect to the inner flange portion 402 and the cover portion 41. In the present embodiment, the pressing member 42 is attached from the other side in the height direction H to the other ends of the inner flange portion 402 and the cover portion 41 in the height direction H. Specifically, the pressing member 42 is fixed to the inner flange portion 402 by screwing.

[0038] The packing 43 is disposed between the lid main body portion 40 and the cover portion 41 and the pressing member 42 in the height direction H. Therefore, the packing 43 is also in an annular shape (specifically, a circular ring shape) in which the inner diameter is smaller than the inner diameter at the other end of the inner flange portion 402 in the height direction H and the outer diameter at the other end of the cover portion 41 in the height direction H, and the outer diameter is smaller than the inner diameter of the standing wall portion 400, similar to the pressing member 42. By attaching the pressing member 42 to the inner flange portion 402 from the other side in the height direction H, the packing 43 is sandwiched between the lid main body portion 40 and the cover portion 41 and the pressing member 42, and seals the gap between the lid main body portion 40 and the cover portion 41 and the pressing member 42. Further, in the present embodiment, by attaching the pressing member 42 to the inner flange portion 402 from the other side in the height direction H, the cover portion 41 is fixed from the other side in the height direction H by the pressing member 42 and the packing 43.

[0039] In the height direction H, the other ends of the standing wall portion 400 and the outer flange portion 401 in the height direction H are brought into contact with one end of the side wall 31 and the flange portion 310 in the height direction H, and a bolt is inserted into the bolt insertion hole of the outer flange portion 401 and the bolt insertion hole of the flange portion 310, whereby the lid body 4 is attached in a state of being fixed to the container body 3. Thereby, the explosion-proof container 2 is configured. As shown in FIG. 2, the explosion-proof container 2 of the present embodiment is circular in a front view.

[0040] When the lid 4 closes the opening 3a of the container body 3, an internal space (not numbered) is formed inside the explosion-proof container 2. The internal space includes a container space 2a formed by the container body 3 and a lid space 2b formed by the lid 4. Further, the lid space 2b includes a main body space 2c formed by the lid main body portion 40 and a cover space 2d formed by the dome-shaped cover portion 41.

[0041] Here, as shown in FIGS. 2 and 3, in this embodiment, the outer flange portion 401 and the flange portion 310 are connected via a hinge h. Therefore, the lid 4 is configured to be removable from the container body 3. Specifically, the bolt is removed from the bolt insertion hole and the bolt insertion hole, and the lid 4 connected to the container body 3 via the hinge h is rotated about the hinge h in the vertical direction D. Thereby, the opening 3a of the container body 3 can be opened.

[0042] The internal device 5 is housed inside the explosion-proof container 2. The internal device 5 includes a device main body (not numbered) and a device fixing portion 6. As shown in FIGS. 1 to 4, the device main body of this embodiment includes a camera 7 and a covering member 8. Further, as shown in FIG. 4, the device main body of this embodiment further includes a lightning surge 9 in addition to the above.

[0043] The camera 7 is, for example, a general-purpose surveillance camera (specifically, a network camera). This camera 7 includes a camera housing 70 that is a container and imaging means (not numbered) provided in the camera housing 70.

[0044] The camera housing 70 of this embodiment is configured in a cylindrical shape. The diameter of the camera housing 70 is shorter than the inner diameter at the other end in the height direction H of the cover portion 41, the inner diameters of the pressing member 42, and the packing 43. Therefore, as shown in FIG. 4, the camera housing 70 of this embodiment can be inserted into the cover portion 41, the pressing member 42, and the packing 43. Further, one end portion of the camera housing 70 in the height direction H is tapered such that it becomes longer in a direction orthogonal to the height direction H as it advances to the other side in the height direction H. On the other hand, a cable connection portion for connecting a cable (for example, a LAN cable) is provided at the other end portion of the camera housing 70 in the height direction H.

[0045] The photographing means is for performing photographing in the camera 7. This photographing means is an imaging unit located inside the camera housing 70, and includes a photographing unit (not numbered) having an image sensor built in the camera housing 70, and a light guide unit 71 that guides imaging light to the imaging unit. Note that the angle of view of the photographing unit of this embodiment is 186° in the vertical direction D and 186° in the horizontal direction W. Therefore, the camera 7 of this embodiment is an omnidirectional camera 7 (so-called "fisheye camera") that can photograph the entire range of directions (specifically, 360° around the optical axis).

[0046] The light guide unit 71 is made of a material that transmits light (for example, a resin such as polycarbonate). The light guide unit 71 is provided at one end portion of the camera housing 70 in the height direction H. This light guide unit 71 is disposed at the center of the vertical direction D and the horizontal direction W of the camera housing 70. Therefore, the light guide unit 71 is disposed at one end of the camera housing 70 in the height direction H. As shown in FIGS. 2 and 3, the light guide unit 71 of this embodiment is configured to be circular in a front view and dome-shaped in a side view.

[0047] Here, among one end portion of the camera housing 70 in the height direction H, the periphery of the light guide portion 71 is configured as a peripheral portion (not numbered) disposed around the light guide portion 71. This peripheral portion has an L* value of at least 70 or more in the L*a*b* color system defined in JIS Z8781-4:2013. Therefore, in the present embodiment, when shooting is performed through the cover portion 41 in a state where only the camera 7 is housed in the explosion-proof container 2 without taking measures against reflection, as shown in FIG. 5C, the peripheral portion is reflected on the inner surface of the cover portion 41, and the reflected peripheral portion appears in the image. Thus, the image captured by the camera 7 is whitened by the reflected peripheral portion.

[0048] By the way, in the present embodiment, the photographing means has an L* value smaller than the L* value of the peripheral portion in the L*a*b* color system defined in JIS Z8781-4:2013. Therefore, in FIG. 5C, the difference in L* value (in other words, the brightness difference) between the peripheral portion and the photographing means appears in the image captured by the camera 7. Specifically, as shown in FIG. 5C, a circular region (i.e., the reflected light guide portion 71 and its shape) where the subject is clearly imaged is disposed at the center of the image, and an annular region with a whitish color (i.e., the reflected peripheral portion) is disposed around it.

[0049] That is, when no measures against reflection are taken, the image captured by the camera 7 has a lower quality because the image is whitened by the reflected peripheral portion. Therefore, in the present embodiment, as a measure against reflection, the peripheral portion is covered with the covering member 8.

[0050] The covering member 8 is configured to cover the entire area of the peripheral portion. This covering member 8 covers the peripheral portion from the side facing the inner surface of the cover portion 41 (in this embodiment, one side in the height direction H). As shown in FIGS. 2 and 3, the covering member 8 of this embodiment is configured in a circular shape with a hole having the same size as the light guide portion 71 formed at the center in a front view, and is configured in a tapered shape with a larger diameter as it progresses from one side to the other side in the height direction H. Further, the covering member 8 has a reflection suppressing color with an L* value of 0 to 60 (preferably, an L* value of 0 to 20) in the L*a*b* color system defined in JIS Z8781-4:2013. Specifically, as an example, the covering member 8 has an L* value of 50. Also, the covering member 8 of this embodiment has a* and b* values of 0. That is, the covering member 8 of this embodiment is a dark color such as black or dark gray. Therefore, the covering member 8 of this embodiment is achromatic and has no chroma. Specifically, the surface on one side in the height direction H of the covering member 8 is black. In addition, the covering member 8 of this embodiment is configured such that the L* values of the entire area are the same. Furthermore, the covering member 8 is formed of a resin film. Note that the covering member 8 is an outer peripheral portion disposed on the outer periphery of the light guide portion 71.

[0051] In this embodiment, the covering member 8 is attached only to the peripheral portion of the camera housing 70 and is not attached to the side surface of the cylindrical camera housing 70.

[0052] One side in the height direction H of the camera 7 is disposed in the cover space 2d. Specifically, the light guide portion 71, the peripheral portion, and the covering member 8 are disposed in the cover space 2d. And the light guide portion 71, the peripheral portion, and the covering member 8 face the inner surface of the cover portion 41. Therefore, the orientation of the camera 7 is fixed with respect to the explosion-proof container 2. Incidentally, since the light guide portion 71 and the peripheral portion face the inner surface of the cover portion 41, as shown in FIG. 5C, the shape of the reflected light guide portion 71 and the peripheral portion are reflected in the video taken by the imaging means. As shown in FIG. 3, at least a part of the light guide portion 71 and the covering member 8 is disposed on one side of the lid main body portion 40 in the height direction H.

[0053] The equipment fixing part 6 is for fixing the internal equipment 5 inside the explosion-proof container 2. As shown in FIG. 4, the equipment fixing part 6 of the present embodiment includes an equipment mounting plate 60 for mounting the internal equipment 5, and a mounting connection part 61 for mounting the equipment mounting plate 60 inside the explosion-proof container 2.

[0054] The equipment mounting plate 60 has a thickness in the height direction H and is a plate-shaped member extending in a direction orthogonal to the height direction H. The equipment mounting plate 60 of the present embodiment has lengths in the longitudinal direction D and the transverse direction W shorter than the inner diameter of the explosion-proof container 2. Therefore, the equipment mounting plate 60 can be accommodated inside the explosion-proof container 2. Also, a camera 7 is mounted on one side of the equipment mounting plate 60 in the height direction H, and a lightning surge 9 is mounted on the other side of the equipment mounting plate 60 in the height direction H. Furthermore, the equipment mounting plate 60 is arranged in the container space 2a. Thus, the lightning surge 9 is arranged in the container space 2a. Note that the equipment mounting plate 60 of the present embodiment is configured to be longer than the camera 7 in the direction orthogonal to the height direction H. In addition, an insertion hole through which a cable is inserted is formed in the equipment mounting plate 60 for connecting a cable to the cable connection part of the camera 7 mounted on the equipment mounting plate 60. Thus, by connecting the lightning surge 9 and the camera 7 (specifically, the cable connection part) with a cable through the insertion hole and connecting the cable inserted into the explosion-proof container 2 through the cable insertion hole 311 to the lightning surge 9, the cable inserted into the explosion-proof container 2 can be connected to the camera 7 via the lightning surge 9.

[0055] The mounting connection part 61 is for connecting the equipment mounting plate 60 to the pressing member 42 in the height direction H. In the present embodiment, a plurality of mounting connection parts 61 are arranged at a predetermined interval around the height direction H. Here, as described above, the camera 7 is mounted on the equipment mounting plate 60, the pressing member 42 is fixed to the inner flange part 402, and the mounting connection part 61 connects the equipment mounting plate 60 and the pressing member 42 in the height direction H. Thus, the camera 7 is mounted on the lid body 4 via the equipment fixing part 6.

[0056] As described above, according to the present embodiment, by covering the peripheral portion with the covering member 8, it is possible to prevent the reflected peripheral portion from being reflected in the video captured by the camera 7. Here, the covering member 8 has a reflection suppressing color with an L* value of 0 to 60 in the L*a*b* color system defined in JIS Z8781-4:2013. Therefore, it is possible to suppress the light that enters the cover space 2d from the cover portion 41 from being reflected by the covering member 8 which is the outer peripheral portion. Thus, it is possible to prevent the video captured by the camera 7 from becoming whitish. Therefore, as shown in FIG. 5A, it is possible to capture a beautiful video.

[0057] Also, as shown in FIG. 5A, in the present embodiment, by covering the peripheral portion with the covering member 8, it is possible to prevent the difference in L* value (in other words, the brightness difference) between the peripheral portion and the imaging means from appearing in the video captured by the camera 7. That is, it is possible to prevent the shape of the light guide portion 71 from appearing in the video captured by the camera 7.

[0058] Further, the covering member 8 of the present embodiment has an L* value of 0 to 60. Here, in the case of the covering member 8 with an L* value of 80 which is a comparative example shown in FIG. 5B, the reflected covering member 8 is reflected in the video captured by the camera 7. On the other hand, as shown in FIG. 5A, when the L* value of the covering member 8 is 0 to 60 (specifically, the L* value is 50), it is possible to prevent the reflected covering member 8 from being reflected in the video captured by the camera 7.

[0059] Also, in the present embodiment, since it is possible to take measures against reflection by covering the peripheral portion with the covering member 8, for example, it is possible to take measures against reflection at a lower cost than performing an antireflection process on the inner surface of the cover portion 41.

[0060] In addition, in the present embodiment, in the inner and outer directions of the explosion-proof container 2, the total length of the side wall 31 and the flange portion 310 and the total length of the standing wall portion 400 and the outer flange portion 401 are set to prevent the flame inside the explosion-proof container 2 from escaping to the outside and igniting the explosive atmosphere existing outside through the joint surface between the container body 3 and the lid body 4. Therefore, when an explosion occurs inside the explosion-proof container 2, it is possible to prevent ignition of the explosive atmosphere existing outside the explosion-proof container 2 (that is, flame escape) through the gaps between the side wall 31 and the flange portion 310 and between the standing wall portion 400 and the outer flange portion 401. Furthermore, the total length of the side wall 31 and the flange portion 310 and the total length of the standing wall portion 400 and the outer flange portion 401 can lower the temperature until heat is transferred to the outside of the explosion-proof container 2 through the joint surface between the container body 3 and the lid body 4.

[0061] In addition, in the present embodiment, one end of the side wall 31 and the flange portion 310 in the height direction H and the other end of the standing wall portion 400 and the outer flange portion 401 in the height direction H are configured to reduce the gap between the joint surfaces when joining the container body 3 and the lid body 4 in order to prevent the flame inside the explosion-proof container 2 from escaping to the outside through the gap between the container body 3 and the lid body 4. Therefore, it is possible to further prevent flame escape from occurring.

[0062] In addition, in the present embodiment, the container body 3 and the lid body 4 are fixed by bolts. Therefore, the container body 3 and the lid body 4 can be fixed more firmly. Further, since the bolt insertion holes and the bolt insertion through-holes are arranged at equal intervals around the height direction H, it is possible to prevent the fixing between the container body 3 and the lid body 4 from being weakened as a whole and to surely ensure the airtightness with the outside. In particular, in the entire area around the height direction H, the gap between one end of the side wall 31 and the flange portion 310 in the height direction H and the other end of the standing wall portion 400 and the outer flange portion 401 in the height direction H can be reduced.

[0063] In addition, in the present embodiment, since the outer flange portion 401 and the flange portion 310 are connected via the hinge h, the lid body 4 is configured to be detachable from the container body 3. Therefore, when performing maintenance inside the explosion-proof camera 1, it is not necessary for the operator to hold the lid body 4 removed from the container body 3 by hand, so that the workability can be improved.

[0064] In addition, a lightning surge 9 is attached to the other side in the height direction H of the equipment mounting plate 60 of the present embodiment. Therefore, when the lid body 4 is removed from the container body 3 via the hinge h, the lightning surge 9 is disposed on the side closer to the operator (for example, one side in the height direction H). Therefore, in a state where the lid body 4 is removed from the container body 3, it is easy to perform wiring work on the lightning surge 9. That is, it is easy to connect the cable inserted into the explosion-proof container 2 through the cable insertion hole 311 to the lightning surge 9.

[0065] In addition, in the present embodiment, the covering member 8 is formed of a resin film. Therefore, it is possible to hardly cause a pressure bias in the explosion-proof container 2. For example, when an explosion occurs in the container space 2a due to the lightning surge 9 disposed in the container space 2a, it is possible to prevent the pressure in the explosion-proof container 2 from becoming even higher (that is, pressure buildup occurs) due to a secondary explosion caused by this explosion.

[0066] Note that the present invention is not limited to the above embodiment, and can be appropriately changed without changing the gist of the invention.

[0067] In the above embodiment, the camera 7 was configured as an omnidirectional camera. However, the present invention is not limited to this, and the camera 7 may be one having a narrower viewing angle than an omnidirectional camera and a fixed orientation (so-called fixed-point camera). Further, the camera 7 may be configured to be capable of panning, tilting, and zooming.

[0068] Further, the camera 7 may be configured to incorporate a microphone and perform recording in conjunction with shooting. Here, for example, when a microphone hole is formed at one end of the camera housing 70, the covering member 8 is disposed around the periphery so as to secure the microphone hole.

[0069] In the above embodiment, the outer flange portion 401 and the flange portion 310 are connected via the hinge h, so that the lid 4 is configured to be removable from the container body 3. However, the present invention is not limited to this, and for example, the lid 4 and the container body 3 may be attached by screwing.

[0070] In the above embodiment, the case where the explosion-proof container 2 is circular in a front view has been described. However, the present invention is not limited to this, and for example, the explosion-proof container 2 may be angular in a front view.

[0071] Further, the cover portion 41 of the above embodiment was configured in a dome shape. However, the present invention is not limited to this, and for example, the cover portion 41 may have a flat plate shape extending in the vertical direction D and the horizontal direction W.

[0072] In the above embodiment, the case where the explosion-proof container 2 has a pressure-resistant explosion-proof structure has been described. However, the present invention is not limited to this, and the explosion-proof container 2 may have another type of explosion-proof structure (for example, an internal pressure explosion-proof structure, a safety increased explosion-proof structure) instead of or in addition to the pressure-resistant explosion-proof structure.

[0073] In the above embodiment, the case where the covering member 8 is made of a resin film has been described. However, the present invention is not limited to this, and for example, the covering member 8 may be made of a cloth material or a paper material.

[0074] In the above embodiment, reflection was prevented by covering the peripheral portion with the covering member 8. Therefore, the covering member 8 was the outer peripheral portion. However, the present invention is not limited to this, and for example, reflection may be prevented by painting the peripheral portion with a reflection suppressing color having an L* value of 0 to 60 in the L*a*b* color system defined in JIS Z8781-4:2013. In this case, the peripheral portion is the outer peripheral portion, and the covering member 8 may not be provided.

[0075] Also, for the covering member 8 of the above embodiment, the a* value and the b* value were 0. That is, the covering member 8 of the above embodiment was a dark color such as black or dark gray. However, not limited thereto, the covering member 8 may have at least one or more of the a* value and the b* value. That is, the covering member 8 may be a chromatic color.

[0076] Also, the case where the covering member 8 of the above embodiment is configured such that the L* values in the entire area are the same has been described. However, not limited thereto, the L* values may be different at each point on the surface of the covering member 8 facing the inner surface of the cover portion 41. Therefore, for example, the covering member 8 may be configured such that the L* value decreases as it approaches the center from the outer edge.

Explanation of Reference Numerals

[0077] 1: Explosion-proof camera, 2: Explosion-proof container, 2a: Container space, 2b: Cover space, 2c: Main body space, 2d: Cover space, 3: Container main body, 30: Bottom plate, 31: Side wall, 310: Flange portion, 311: Cable insertion hole, 3a: Opening, 3P: Packing, 4: Cover, 40: Cover main body portion, 400: Standing wall portion, 401: Outer flange portion, 402: Inner flange portion, 41: Cover portion, 42: Pressing member, 43: Packing, 4a: Through hole, 4P: Packing, 5: Internal equipment, 6: Equipment fixing portion, 60: Equipment mounting plate, 61: Mounting connection portion, 7: Camera, 70: Camera housing, 71: Light guide portion, 8: Covering member, 9: Lightning surge, h: Hinge, H: Height direction, D: Longitudinal direction, W: Lateral direction

Claims

1. A camera including a light guide unit that guides imaging light to an imaging unit located inside; An outer peripheral part disposed on the outer periphery of the light guide unit; An explosion-proof container that houses the camera and the outer peripheral part, the explosion-proof container including a cover part that has light transmissibility and covers the light guide unit and the outer peripheral part; and The outer peripheral part is disposed to face the inner surface of the cover part, and has a reflection suppressing color having an L* value of 0 to 60 in the L*a*b* color system defined in JIS Z8781-4:2013. An explosion-proof camera characterized by this.

2. The explosion-proof camera according to claim 1, wherein the outer peripheral part is a covering member that covers a peripheral part disposed around the light guide unit from a side facing the inner surface of the cover part.

3. The explosion-proof camera according to claim 2, wherein the covering member is configured such that the L* value of the entire area is the same on the surface facing the inner surface of the cover part.

4. The explosion-proof camera according to claim 2 or 3, wherein the covering member is constituted by a resin film.

5. The explosion-proof camera according to claim 1, wherein the camera is fixed in orientation with respect to the explosion-proof container and can photograph in all directions.

6. The explosion-proof container includes a cylindrical container body and a lid that closes the container body, The lid includes the cover part and is configured to be removable with respect to the container body, The explosion-proof camera according to claim 1, wherein the camera is attached to the lid.

7. The explosion-proof camera according to claim 6, wherein the container body and the lid are connected via a hinge.

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