JP2023007063A - Imaging apparatus - Google Patents

Abstract

To provide an imaging apparatus that achieves appropriate heat radiation from an infrared emitting diode and can prevent a reduction in waterproof performance due to creep deformation of a resin housing.SOLUTION: An imaging apparatus has: a housing that includes a cover part and a base part and is formed of resin; a camera part that is accommodated inside the housing; a circuit board that is fixed to the base part and has an infrared emitting diode mounted on a surface facing the cover part; a heat radiation member that is arranged between the circuit board and the base part and radiates heat from the infrared emitting diode; and a sealing member that is arranged on an outer periphery of the housing while being pressed by the cover part and the base part. The infrared emitting diode is arranged closer to the sealing member in a space between the camera part and the sealing member. The heat radiation member is not in contact with an inner peripheral wall of the housing. A first heat insulating space is formed between the heat radiation member and the base part to overlap the infrared emitting diode when seen from the cover part.SELECTED DRAWING: Figure 2

Description

The present invention relates to an imaging device.

Conventionally, a network camera having a waterproof structure has been proposed in order to suppress the intrusion of water such as rain. Also, a network camera equipped with an infrared light emitting diode (IR LED) has been proposed in order to record good images even in a dark environment (see Patent Document 1). As the temperature of the IR LED increases, the irradiation efficiency of the IR LED decreases, so the network camera equipped with the IR LED must have a heat dissipation structure.

Japanese Patent No. 4273498

In recent years, network cameras are required to use resin housings made of resin in order to reduce weight and cost. In the image pickup apparatus of Patent Document 1, in order to have a waterproof structure while using a resin housing, for example, a gasket or the like may be arranged on the outer periphery of the housing. However, in the imaging device of Patent Document 1, the board on which the IR LED is mounted is in direct contact with the housing, and the IR LED is arranged at a position close to the outer periphery of the housing. As a result, when a certain amount of stress is applied to the area where the reaction force of the gasket is applied at a certain temperature, creep deformation occurs in which the deformation of the area where the stress is applied increases with the passage of time. There is a possibility that the amount of pressure will decrease. As a result, the sealing performance of the gasket may deteriorate, making it impossible to guarantee the waterproof performance. Moreover, if the substrate is arranged so as not to come into direct contact with the housing, the heat of the IR LED cannot be sufficiently dissipated, and the irradiation efficiency of the IR LED may decrease.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image pickup device that can appropriately dissipate heat from an infrared light emitting diode and can suppress deterioration in waterproof performance due to creep deformation of a resin housing.

An imaging device as one aspect of the present invention includes a cover portion and a base portion, a housing formed of resin, a camera portion housed in the housing, and a surface on the side of the cover portion fixed to the base portion. a circuit board on which infrared light emitting diodes are mounted, a heat dissipating member disposed between the circuit board and the base for dissipating heat from the infrared light emitting diodes, and a housing pressed against the cover and the base The infrared light emitting diode is arranged on the side closer to the sealing member in the space between the camera section and the sealing member, and the heat dissipation member is arranged inside the housing. A first heat insulating space is formed between the heat radiating member and the base portion so as not to contact the peripheral wall and overlap the infrared light emitting diode when viewed from the cover portion side.

According to the present invention, it is possible to provide an imaging device that can appropriately dissipate heat from an infrared light emitting diode and can suppress deterioration in waterproof performance due to creep deformation of a resin housing.

1 is an overall view of a network camera that is an example of an imaging device according to an embodiment of the present invention; FIG. 1 is a cross-sectional view of a network camera; FIG. 1 is an exploded sectional view of a network camera; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same reference numerals are given to the same members, and overlapping descriptions are omitted.

FIG. 1 is an overall view of a network camera 100, which is an example of an imaging device according to an embodiment of the present invention. The network camera 100 has a housing 130 and a lens protection member 140, and is capable of capturing and recording images.

Housing 130 includes cover portion 110 and base portion 120 . Each of the cover portion 110 and the base portion 120 can be made by molding a resin such as polycarbonate. The base portion 120 is fixed to a wall or a vehicle with screws or the like through installation holes. The cover part 110 and the base part 120 each have a fastening part 150 and are fastened to each other with screws or the like. Although the housing 130 is composed of two parts in this embodiment, it may be composed of three or more parts. Also, the cover part 110 and the base part 120 may be fixed using claw fitting or adhesion.

The cover portion 110 includes a window (window portion) 160 for irradiating light (IR light) from an infrared light emitting diode (IR LED). The window 160 is integrally molded with the cover portion 110 and is made of black transparent polycarbonate or the like, for example. The window 160 may be adhesively fixed to the cover portion 110, or may be screwed together with the waterproof member. The inside of the housing of the window 160 has a lens shape and can collect or diffuse the IR light. By irradiating with IR light, it is possible to take pictures even in a dark environment such as at night. The window 160 is located approximately in the middle of the fastening portion 150 . Thereby, the irradiation range of the IR LED can be widened. Window 160 is tinted to a color that blocks visible light and transmits IR light. As a result, the parts inside the housing cannot be seen from the outside. The wavelength of IR light is approximately 750 nm to 950 nm.

The lens protection member 140 has a hemispherical shape and protects the lens and other parts accommodated inside the housing from impact and dust. The lens protection member 140 is fixed to the cover portion 110 by ultrasonic welding or the like. Since the network camera 100 takes an image through the lens protection member 140, the lens protection member 140 is treated as an optical component, and transparency and dimensional accuracy are important. The lens protection member 140 is made of transparent polycarbonate or the like, for example.

FIG. 2 is a cross-sectional view of the network camera 100. As shown in FIG. A gasket (sealing member) 180, a camera section 200, a circuit board 300, an IR LED 320, a heat radiation member 340, and a holding member 360 are housed inside the housing. The gasket 180 is made of, for example, silicon rubber or the like, and is arranged on the outer periphery of the housing while being pressed against the boundary between the cover portion 110 and the base portion 120 . Here, the outer circumference includes not only the strictly outer circumference but also the substantial outer circumference (substantially the outer circumference). The gasket 180 has a substantially rhombic shape and is configured to reduce reaction force when pressed. By pressing the gasket 180, the adhesion of the gasket 180 to the housing 130 is enhanced, and the sealing performance is exhibited. This is the same as the O-ring sealing structure. The lens protection member 140, the window 160, and the gasket 180 form a sealed structure for the housing 130, which can prevent water and dust from entering the housing 130. FIG. The shape of the gasket 180 may be another shape such as an X shape or an elliptical shape that has less reaction force. Also, as the gasket 180, a waterproof sealing material or foam may be used.

The camera section 200 is arranged substantially at the center of the housing, and includes a lens 210 , a lens holder 230 , an imaging board 240 , a lens cover 250 and a camera holder 260 . The lens 210 is threadedly held by a lens holder 230 and is movable in the optical axis direction to adjust the focus. The imaging board 240 includes an imaging element and is fixed to the lens holder 230 by adhesion or the like. An imaging device is one of heat-generating components. If the temperature of the image pickup device becomes too high, noise will occur in the image. Therefore, it is necessary to radiate the heat of the imaging device to the lens cover 250 and the like, and to adopt a structure that does not receive heat from another heat source such as a substrate. For example, a method of insulating by forming a wall that blocks the movement of heat is conceivable. The lens holder 230 is gripped and fixed to the lens cover 250 . The lens cover 250 is made by, for example, metal die-casting or resin molding such as polycarbonate, is held so as to be covered by the camera holder 260 and the base section 120, and is configured to be capable of tilting and rotating. An opening is formed in front of the lens cover 250 for photographing an image, and a hole through which the wire 270 and the like are passed is formed in the rear of the lens cover 250 . The camera holder 260 is made by molding a resin such as polycarbonate, and is continuously open from a substantially horizontal position to a substantially vertical position, which is the shooting range. Also, the camera holder 260 regulates the range of tilting operation of the lens cover 250 .

The holding member 360 is made by molding a resin such as polycarbonate, holds the camera section 200 through the camera holder 260 so as to be pan-rotatable, and is fixed to the base section 120 using screws or the like. The pan rotation axis is substantially perpendicular to the installation surface. The holding member 360 is open so as not to block irradiation of IR light from the IR LED 320 . Moreover, the holding member 360 includes a rib 364 surrounding the IR LED 320 . Ribs 364 prevent IR light from IR LEDs 320 from passing through the interior of housing 130 and entering lens 210 . In addition, the rib 364 prevents the air warmed by the IR LED 320 from moving toward the camera section 200 , making it difficult for heat to be conducted to the camera section 200 .

The circuit board 300 is fixed to the base portion 120 using screws or the like, and has overall control functions of the network camera 100, such as control of the IR LED 320, power supply, camera control, and network connection. An opening is formed in the center of the circuit board 300, and the camera section 200 is arranged in the opening. The circuit board 300 and the imaging board 240 are electrically connected by a wire 270 or the like. Note that the circuit board 300 and the imaging board 240 may be electrically connected by a flexible board, a flat cable, a thin coaxial cable, or the like. The camera unit 200 converts the light received through the lens protection member 140 and the lens 210 into an electric signal by the imaging element and transmits the electric signal to the circuit board 300 . The circuit board 300 records the received video data and distributes it over the network. The IR LED 320 is mounted on the upper surface of the circuit board 300 and arranged on the side closer to the gasket 180 in the space between the camera section 200 and the gasket 180 . Thereby, the IR LED 320 can be brought as close to the cover part 110 and the window 160 as possible, and the irradiation angle can be kept wide. Also, by keeping the IR LED 320 away from the camera section 200, the mutual thermal influence can be reduced.

The heat dissipation member 340 is made of a metal plate with high thermal conductivity such as aluminum, and is arranged between the circuit board 300 and the base portion 120 . Note that the heat dissipation member 340 may be made using another metal material such as copper, or may be made using a thermal diffusion member such as a graphite sheet. The heat dissipation member 340 has an extension part 344 close to the lower surface of the circuit board 300 to dissipate the heat of the IR LEDs 320 from the lower surface side of the circuit board 300 . The heat transfer member 370 is sandwiched between the extending portion 344 and the circuit board 300 , making it easier to transfer heat from the IR LEDs 320 to the heat dissipation member 340 . Note that the extending portion 344 may function as a contact portion that contacts the circuit board 300 without providing the heat transfer member 370 . A heat insulating portion (first heat insulating space) 380 is formed between the extending portion 344 and the base portion 120 so as to overlap the IR LED 320 when viewed from the cover portion 110 side. The heat radiating member 340 is in contact with the base portion 120 at a position away from the gasket 180 on the central side of the heat insulating portion 380 . Furthermore, the heat dissipation member 340 is not in contact with the inner peripheral wall 121 of the base portion 120 .

A plurality of (two in this embodiment) IR LEDs 320 are housed inside the housing. The two IR LEDs 320 are arranged substantially point-symmetrically around the pan rotation axis of the camera unit 200 (at equal intervals along the rotation direction around the pan rotation axis). Therefore, the irradiation range of the IR LED 320 covers all directions around the network camera 100 . Accordingly, in a dark shooting environment, the camera unit 200 can shoot regardless of the pan rotation position. In addition, a plurality of (two in this embodiment) heat dissipating members 340 are housed inside the housing. The two heat dissipating members 340 are arranged substantially point-symmetrically around the pan rotation axis of the camera unit 200 (at equal intervals along the rotation direction around the pan rotation axis), and dissipate the heat of the corresponding IR LEDs 320. . In this embodiment, the number of IR LEDs 320 and heat dissipation members 340 is two, but may be three or more.

FIG. 3 is an exploded cross-sectional view of the network camera 100. As shown in FIG. Heat dissipation of the IR LED 320 will be described below. First, heat dissipation by heat conduction will be described. Heat generated by the IR LEDs 320 when irradiated with IR light is directly transferred to the circuit board 300 . Then, the heat is transmitted from the lower surface side of the circuit board 300 to the extending portion 344 of the heat radiating member 340 via the heat transfer member 370 . Since the heat radiating member 340 has a high thermal conductivity, the heat transferred to the extended portion 344 is diffused in the planar direction of the heat radiating member 340 . Since the heat dissipating member 340 is fixed to the base portion 120 at a place avoiding the heat insulating portion 380, the heat transmitted to the heat dissipating member 340 is transferred to the housing 130 from a place other than the heat insulating portion 380, and is radiated to the outside of the housing 130. be done.

Next, heat radiation by thermal convection will be described. On the upper surface side of the circuit board 300, the air heated by the IR LEDs 320 convects in the LED space (second heat insulating space) 390 surrounded by the ribs 364 and the circuit board 300, and radiates heat from the window 160 to the outside of the housing. be done. Since the rib 364 prevents heat convection on the camera section 200 side, the camera section 200 and the IR LED 320 are less likely to be affected by heat. Also, on the lower surface side of the circuit board 300 , the air in the heat insulating portion 380 is warmed by the heat transmitted from the IR LED 320 to the extending portion 344 . However, since a solid generally has a higher thermal conductivity than a gas, much of the heat of the IR LED 320 is diffused in the planar direction of the heat dissipation member 340 through the heat conduction path described above. Thereby, it is possible to prevent the air in the heat insulating portion 380 from becoming too high. Further, the base portion 120 is formed with a wall 122 that blocks the thermal insulation portion 380 and the camera portion 200 in order to prevent the air directly warmed from the lower surface of the circuit board 300 from moving toward the camera portion 200 side. Furthermore, the heat insulating portion 380 and the LED space 390 are formed so as to overlap each other on the projection plane viewed from above the housing (when viewed from the cover portion 110 side). Thereby, the heat of the IR LED 320 can be concentrated on the extending portion 344, and the heat can be quickly diffused by the heat conduction of the heat radiation member 340 which is solid.

By dissipating heat from the IR LEDs 320 with the above-described configuration, heat from the IR LEDs 320 is less likely to be transmitted to the vicinity of the IR LEDs 320 of the base portion 120 and the camera portion 200 .

In this embodiment, the gasket 180 is arranged in a pressed state in order to secure the waterproof performance of the housing. Therefore, the reaction force of the gasket 180 acts on the cover portion 110 and the base portion 120 in a direction in which they open each other. Since the base portion 120 has a plate-like shape compared to the cover portion 110, it has low rigidity and is easily deformed. Further, the position A of the base portion 120 near where the IR LED 320 is arranged is distant from the fastening portion 150 and thus easily deformed. If the position A where the reaction force of the base portion 120 acts is heated, creep deformation may occur. When the base portion 120 deforms, the pressing amount of the gasket 180 decreases. As a result, the sealing performance of the gasket 180 may deteriorate, and the waterproof performance may not be ensured.

In the present embodiment, the heat dissipation member 340 and the heat insulating portion 380 make it difficult for heat to be conducted to the position A of the base portion 120 . That is, it is possible to suppress the occurrence of creep deformation because it is possible to suppress the increase in temperature that causes creep deformation.

As described above, according to the configuration of the present embodiment, it is possible to provide an imaging device that can appropriately dissipate heat from the infrared light emitting diode and suppress deterioration of waterproof performance due to creep deformation of the resin housing.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist.

100 network camera (imaging device)
110 cover portion 120 base portion 121 inner peripheral wall 130 housing 180 gasket (sealing member)
200 camera section 300 circuit board 320 infrared light emitting diode 340 heat dissipation member 380 heat insulation section (heat insulation space)

Claims (13)

a housing formed of resin, comprising a cover portion and a base portion;
a camera unit housed in the housing;
a circuit board fixed to the base portion and having infrared light emitting diodes mounted on the surface on the side of the cover portion;
a heat dissipation member disposed between the circuit board and the base portion for dissipating heat from the infrared light emitting diode;
a sealing member arranged on the outer periphery of the housing in a state of being pressed by the cover portion and the base portion;
The infrared light emitting diode is arranged on a side closer to the sealing member in a space between the camera section and the sealing member,
The heat dissipation member does not contact the inner peripheral wall of the housing,
An imaging apparatus according to claim 1, wherein a first heat insulating space is formed between the heat radiating member and the base portion so as to overlap the infrared light emitting diodes when viewed from the cover portion side. 2. The imaging apparatus according to claim 1, wherein the base section includes a wall that blocks the first heat insulating space and the camera section. 3. The imaging apparatus according to claim 1, further comprising a holding member arranged between the cover section and the circuit board for rotatably holding the camera section. 4. The image pickup apparatus according to claim 3, wherein said holding member has a rib that surrounds said infrared light emitting diode. 5. The imaging device according to claim 4, wherein the infrared light emitting diode is arranged inside a second heat insulating space surrounded by the rib and the circuit board. 6. The imaging apparatus according to claim 5, wherein the first heat insulating space and the second heat insulating space are formed so as to overlap when viewed from the cover portion side. The imaging apparatus according to any one of claims 1 to 6, wherein the heat dissipation member has a contact portion that contacts the circuit board. 7. The imaging apparatus according to claim 1, further comprising a heat transfer member sandwiched between the circuit board and the heat dissipation member. 9. The imaging apparatus according to claim 1, wherein the camera section is arranged in an opening formed in the center of the circuit board. 10. The imaging apparatus according to claim 1, wherein the number of said infrared light emitting diodes and said heat radiation members is plural. 11. The imaging apparatus according to claim 10, wherein the plurality of infrared light emitting diodes and the plurality of heat radiation members are arranged at regular intervals along the rotation direction about the pan rotation axis of the camera section. . The imaging apparatus according to any one of claims 1 to 11, wherein the heat radiating member is in contact with the base portion on the central side of the first heat insulating space. The imaging apparatus according to any one of claims 1 to 12, wherein the cover section includes a window section through which light from the infrared light emitting diode is transmitted.

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