JP2022053272A - Imaging apparatus - Google Patents

Abstract

To provide an imaging apparatus that is power-saving, has good workability for parts replacement, and improved mechanical reliability.SOLUTION: An imaging apparatus includes a housing with an aperture, a protective transparent plate that is placed in the aperture of the housing, a camera unit that is located inside the housing and takes a picture of a subject through the protective transparent plate, a heater unit with a heat-generating member, and a heater holder that secures the protective transparent plate and the heater unit to the housing. The heater unit is held in the heater holder by a snap-fit.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image pickup device for monitoring or the like.

Currently, surveillance cameras are used in various places regardless of the installation location. For example, there is a box-shaped surveillance camera for outside the vehicle that is installed outside the vehicle of a bus or railroad vehicle and is used for monitoring passengers.
And some surveillance cameras for outside the vehicle are equipped with a heater to melt the ice and snow adhering to the protective window of the camera.

In addition, since the protective window (protective transparent plate) of a surveillance camera for outside the vehicle may be cracked or damaged by flying objects such as stones, it is required that the protective window can be easily replaced.
Patent Document 1 discloses a heater structure of a translucent member attached to a camera housing.

Japanese Unexamined Patent Publication No. 2013-145218

However, in the heater structure disclosed in Patent Document 1 described above, the heater, which is a heating element, is directly fixed to the frame. Therefore, when the coefficient of thermal expansion of the material of the heater and the material of the frame are different, when the heater operates, a load due to thermal expansion is applied to the fixed portion between the heater and the frame.

FIG. 8 is a cross-sectional view showing a heater structure of a conventional surveillance camera. The upper view of FIG. 8 is a cross-sectional view, and the lower view of FIG. 8 is a schematic view showing a disassembled state when the protective transparent plate is replaced. The front cover 206 is fixed to the upper cover 101 by a screw or the like (not shown). The waterproof rubber 111, the heater 112, and the protective transparent plate 103 are sandwiched and held between the front cover 206 and the upper cover 101.

When the front cover 206 was removed when replacing parts such as the protective transparent plate 103, the protective transparent plate 103, the waterproof rubber 111, and the heater 112 were separated into pieces, which made the replacement work complicated. Further, since the heater 112 is in direct contact with the upper cover 101 made of aluminum die casting or the like, the heat generated by the heater 112 is transferred to the upper cover 101, and the protective transparent plate 103 cannot be efficiently heated. rice field.
The present invention has been made to solve the above-mentioned problems of the conventional example, and the object of the present invention is power saving, good workability of parts replacement, and improved mechanical reliability. The purpose is to provide an image pickup device.

In the image pickup device
A housing with an opening and
A protective transparent plate arranged in the opening of the housing,
A camera unit that is arranged inside the housing and shoots a subject through the protective transparent plate, and
A heater unit with a heat generating member and
It has a protective transparent plate and a heater holder for fixing the heater unit to the housing.
The heater unit is configured to be held by the heater holder by a snap fit.

According to the present invention, it is possible to provide an image pickup device that saves power, has good workability for parts replacement, and has improved mechanical reliability.

It is a perspective view of the surveillance camera 100 such as a network camera in an Example. It is sectional drawing of the surveillance camera 100 in an Example. It is an exploded sectional view of the surveillance camera 100 in an Example. It is an exploded perspective view of the surveillance camera 100 in an Example. It is a perspective view of the heater holder 115 of the surveillance camera in an Example. It is sectional drawing around the heater holder unit 116 in an Example. It is an exploded schematic diagram at the time of exchanging a part such as a protective transparent plate 103 in an Example. It is sectional drawing which showed the heater structure of the conventional surveillance camera.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings with reference to examples. In each figure, the same member or element is given the same reference number, and duplicate explanations are omitted or simplified.
Further, in the embodiment, an example applied to a surveillance camera such as a network camera as an image pickup device will be described. However, the imaging device includes a digital still camera, a digital movie camera, a smartphone with a camera, a tablet computer with a camera, an electronic device having an imaging function such as a drone camera, and the like.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, FIGS. 1-7.
FIG. 1 is a perspective view of a surveillance camera 100 such as a network camera in the embodiment.
The surveillance camera 100 is a box-shaped surveillance camera installed outside the vehicle. The upper cover 101 and the lower cover 102 constitute a housing of the surveillance camera 100, and are made of, for example, aluminum die-cast. The protective transparent plate 103 is made of, for example, transparent or translucent glass. An opening is formed in the upper cover 101 of the housing, and a protective transparent plate 103 is arranged in the opening. A camera unit 104, which will be described later, is arranged inside the protective transparent plate 103.

FIG. 2 is a cross-sectional view of the surveillance camera 100 in the embodiment. FIG. 3 is an exploded cross-sectional view of the surveillance camera 100 in the embodiment. FIG. 4 is an exploded perspective view of the surveillance camera 100 in the embodiment.
In FIG. 4, the upper cover 101 shows only a part of the parts. FIG. 5 is a perspective view of the heater holder 115 of the surveillance camera in the embodiment.

A camera unit 104 is arranged inside the housing, and a subject is photographed via the protective transparent plate 103. The camera unit 104 includes a photographing optical system and an image sensor, and by forming a subject image on the image sensor, the subject image is photoelectrically converted to generate a video signal. That is, the camera unit 104 is composed of a lens barrel, various lenses held in the lens barrel, an image sensor such as a CMOS sensor, and the like. The video signal generated by the camera unit 104 is transmitted to the main board 105 by a cable (not shown) or the like.

The main board 105 is an electric board, and various electric components (not shown) are mounted on the main board 105. The main board 105 processes the signal output from the image sensor in the camera unit 104, and further performs compression coding processing. The main board 105 wirelessly distributes a video signal subjected to compression coding processing to an external camera control device such as a user terminal via a network, for example.

The waterproof rubber 111 is arranged between the upper cover 101 of the housing and the protective transparent plate 103, and is a waterproof member that prevents rainwater or the like from entering the inside of the housing. The waterproof rubber 111 is made of, for example, silicon rubber. The thermal conductivity of silicon rubber is about 0.2 W / m · K, which is lower than that of metals such as aluminum. The heater 112 as a heat generating member is a heat generating member. The heater 112 is an FPC type heater, and the heater pattern is arranged in a meandering manner. The heater 112 is electrically connected to the main board 105 by a cable (not shown) or the like.

The sheet metal 113 is, for example, an aluminum sheet metal, and is a heat diffusion member in which the heat generated by the heater 112 is diffused so as to be constant on the surface of the heater 112. The heater unit 114 has a heater 112 and a sheet metal 113. The heater 112 is fixed to the sheet metal 113 by a double-sided tape (not shown) or the like.

The heater holder 115 is made of, for example, plastic. The thermal conductivity of plastic is about 0.2 W / m · K, which is lower than that of metals such as aluminum. As shown in FIG. 5, a first convex portion 118 in contact with the heater unit 114 is formed on the bottom surface of the heater holder 115. A second convex portion 119 is formed on the inside of the side surface of the heater holder 115. A hook claw 117 is formed on the inside of the side surface of the heater holder 115.
The waterproof rubber 111, the heater 112, the sheet metal 113, and the heater holder 115 have a hollow shape whose central portion is rectangular or circular so as not to interfere with the shooting of the camera unit 104.

When the heater unit 114 is assembled to the heater holder 115, the side wall portion of the heater holder 115 on which the hook claw 117 is formed is elastically deformed. The heater unit 114 is temporarily held by a snap fit between the hook claw 117 of the heater holder 115 and the first convex portion 118.

At this time, the sheet metal 113 is arranged between the heater 112 and the heater holder 115. The heater holder unit 116 is composed of a heater unit 114 and a heater holder 115. The heater holder 115 is fixed to the upper cover 101 with a screw (not shown) or the like with the protective transparent plate 103 and the heater unit 114 sandwiched between them. In this state, the heater 112 as the heat generating member is arranged between the protective transparent plate 103 and the sheet metal 113 as the heat diffusion plate.

The heater unit 114 and the bottom surface side of the heater holder 115 are in contact with each other by a first convex portion 118 of the heater holder 115. An air layer is formed in the portion other than the first convex portion 118. Air has a thermal conductivity of 0.02 W / m · K, has a lower thermal conductivity than the heater holder 115 made of plastic, and has a high heat insulating effect.

On the other hand, the side surface side of the heater holder 115 and the heater unit 114 are in contact with each other at the second convex portion 119. The heater holder 115 and the protective transparent plate 103 are in contact with each other at the second convex portion 119.
An air layer is formed between the heater holder 115 and the heater unit 114, and between the heater holder 115 and the protective transparent plate 103 except for the second convex portion 119. The air layer has a lower thermal conductivity and a higher heat insulating effect than the heater holder made of plastic. The second convex portion 119 also functions as a position regulating portion that regulates the positions of the protective transparent plate 103 and the heater unit 114.

The protective transparent plate 103 is surrounded by a waterproof rubber 111 made of silicon rubber and a heater holder 115 made of plastic, and an air layer is further formed between the heater unit 114 and the heater holder 115. Therefore, the heat generated in the heater unit 114 can efficiently heat the protective transparent plate 103. Therefore, the surveillance camera 100 can heat the protective transparent plate 103 to the target temperature in a shorter time with less power consumption.

The heater unit 114 is temporarily held by the heater holder 115 by a snap fit and is not completely fixed.
If the heater unit 114 is fixed to the heater holder 115 with a screw or the like, thermal stress is applied to each component due to the difference in the coefficient of thermal expansion between the aluminum sheet metal 113 and the plastic heater holder 115.

Since the heater holder 115 is made of plastic, there is a risk of creep deformation due to thermal stress. Further, when the heater 112 is fixed with a screw or the like, the screw loosens due to a change in temperature due to ON / OFF of the heater 112.
On the other hand, in this embodiment, since the parts are temporarily held by the snap fit, the possibility of deformation or breakage of the parts due to thermal stress and loosening of the screws can be reduced, and the reliability of the parts can be improved.

FIG. 6 is a cross-sectional view of the periphery of the heater holder unit 116 in the embodiment.
As shown in FIG. 4, the sheet metal 113 is formed with an opening 156, and the heater holder 115 is formed with a recess 157. The temperature sensor 153 is arranged in the opening 156, and the temperature sensor substrate 151 and the elastic member 154 are arranged in the recess 157.

A heat conductive member 155 is filled between the opening 156 and the temperature sensor 153. The heat conductive member 155 is, for example, heat conductive grease or RTV (Room Temperature Vulcanization) silicone rubber. The elastic member 154 urges the temperature sensor substrate 151 toward the sheet metal 113 side of the heater unit 114.

Since the opening 156 of the sheet metal 113 is surrounded by the sheet metal 113, the temperature sensor 153 can measure the temperature of the heater unit 114 more accurately. The plate thickness of the sheet metal 113 and the component height of the temperature sensor 153 are substantially the same, but the plate thickness of the sheet metal 113 is slightly larger. As described above, in the embodiment, the temperature sensor 153 is arranged with respect to the sheet metal 113 as the heat diffusion plate, the difference between the temperature of the heater unit 114 and the temperature measured by the temperature sensor 153 is reduced, and the temperature is measured more accurately. do. As a result, more appropriate heater control according to the temperature change of the heater unit 114 and the temperature change of the external environment becomes possible.

FIG. 7 is an exploded schematic diagram when parts such as the protective transparent plate 103 in the embodiment are replaced. When the heater holder unit 116 is removed from the upper cover 101, it is divided into an upper cover 101, a waterproof rubber 111, a protective transparent plate 103, and a heater holder unit 116. The waterproof rubber 111 may be fixed to the upper cover 101 with an adhesive or the like. Since the heater unit 114 is temporarily held by the heater holder 115 by a snap fit, the heater holder unit 116 is not separated into the heater unit 114 and the heater holder 115 even if they are disassembled. Therefore, workability at the time of replacing the protective transparent plate 103 is improved.

As described above, according to the configuration of the present embodiment, it is possible to provide a heater structure of a surveillance camera having high thermal efficiency, high mechanical reliability of parts, and high interchangeability of the protective transparent plate 103.
Although the present invention has been described in detail based on the preferred embodiments thereof, the present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention. It is not excluded from the scope of the invention.

100 Surveillance camera 101 Top cover 102 Bottom cover 103 Protective transparent plate 104 Camera unit 111 Waterproof rubber 112 Heater 113 Sheet metal 114 Heater unit 115 Heater holder 117 Hook claw 118 First convex part

Claims (9)

A housing with an opening and
A protective transparent plate arranged in the opening of the housing,
A camera unit that is arranged inside the housing and shoots a subject through the protective transparent plate, and
A heater unit with a heat generating member and
It has a protective transparent plate and a heater holder for fixing the heater unit to the housing.
An imaging device characterized in that the heater unit is configured to be held by the heater holder by a snap fit. The image pickup apparatus according to claim 1, further comprising a waterproof member arranged between the housing and the protective transparent plate. The imaging device according to claim 1 or 2, wherein the heater unit has a heat diffusion plate. The image pickup apparatus according to claim 3, wherein the heat generating member is arranged between the protective transparent plate and the heat diffusion plate. The image pickup apparatus according to claim 3 or 4, wherein a temperature sensor is arranged with respect to the heat diffusion plate. The imaging device according to any one of claims 1 to 5, wherein the heater holder is made of plastic. The image pickup apparatus according to any one of claims 1 to 6, wherein an air layer is formed between the heater unit and the protective transparent plate. The image pickup apparatus according to any one of claims 1 to 7, wherein a first convex portion in contact with the heater unit is provided on the bottom surface of the heater holder. The image pickup apparatus according to any one of claims 1 to 8, wherein a second convex portion for restricting the positions of the heater unit and the protective transparent plate is provided on the side surface of the heater holder.

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