JP2002277954A - Camera housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera housing which simplifies a dehumidifying device and reduces its cost and power consumption and so on by removing humidity in the camera housing by a Peltier module and defogging front glass or preventing it from getting fogged and also eliminates the need for a special heater by using the Peltier module for the heat insulation in the camera housing. SOLUTION: The dehumidifying device equipped with the Peltier module 40 and a heat radiation plate 42 is installed in the camera housing 14. The Peltier module 40 is turned on and off according to the detection signal of a temperature sensor 30 or a dewing sensor 32 installed on the front glass 18 to defog the front glass 18 or prevent it from getting fogged. further, the Peltier module 40 is turned on and off according to the detection signal of a temperature sensor 30 detecting the temperature in the camera housing 14 to keep the air in the camera housing 14 at proper temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera housing, and more particularly to a camera housing having a dehumidifying function for removing or preventing fogging of a front glass of the camera housing.

[0002]

2. Description of the Related Art A camera head used outdoors or the like generally stores a television camera in a box-shaped camera housing to protect the television camera from rain and dust. A transparent front glass is provided on the front of the camera housing facing the taking lens of the camera housed inside, and from this front glass the external scene can be taken with the internal TV camera. I have.

Incidentally, a temperature difference between the temperature inside the camera housing and the temperature of the outside air is apt to occur due to self-heating of the camera or the like, and the front glass of the camera housing may be fogged. Conventionally, in order to prevent such fogging, a heater is attached around the front glass, a wire heater is embedded inside the front glass,
Measures have been taken such as coating a conductive film for preventing fogging on the surface of the front glass.

[0004] However, the method of mounting the heater around the front glass has a disadvantage that the fogging at the periphery of the front glass can be removed in a short time, but it takes time to remove the fogging at the center. Further, the method of embedding the wire heater inside the front glass has a disadvantage that the wire heater is reflected when the photographing angle of view of the camera is wide. Furthermore, in the method of coating a conductive film on the surface of the front glass, the conductive film deteriorates the spectral characteristics, and the mirror of the conductive film acts to reflect the solar light when the front surface is exposed to sunlight. There is also a disadvantage that the image on the front of the lens is reflected in the image and that it is expensive.

Therefore, Japanese Patent Application Laid-Open No. Hei 8-205007 discloses that a fin (heat exchanger) is provided inside a camera housing, a fan for circulating air in the camera housing is provided, and the fan circulates and passes through the fin. Dehumidifies the air by condensing the moisture of the air onto the fins. An apparatus has been proposed which removes or prevents fogging of the front glass by blowing dehumidified air or air further heated by a heater onto the front glass.

[0006]

However, the apparatus described in the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-205007 has a problem that the apparatus becomes large and power consumption is large.

The present invention has been made in view of such circumstances, and provides a camera housing capable of removing or preventing fogging of a front glass by enabling dehumidification in the camera housing by a simple device. The purpose is to:

[0008]

According to one aspect of the present invention, there is provided a camera housing in which a camera is housed and a front glass is attached to a front end of the camera facing a taking lens. Wherein the moisture in the camera housing is dehumidified by dehumidifying means using an electronic cooling element to remove or prevent fogging of the front glass.

The invention described in claim 2 is the first invention.
The invention according to claim 1, further comprising a temperature detecting unit that detects a temperature of the front glass, a dew detecting unit that detects dew condensation on the front glass, or a humidity detecting unit that detects humidity in the camera housing, wherein the temperature detection is performed. The on / off of the electronic cooling element is automatically switched according to the level of the temperature detected by the means, the presence or absence of condensation detected by the dew condensation detecting means, or the level of humidity detected by the humidity detecting means. And

[0010] Further, the invention according to claim 3 is based on claim 1.
Alternatively, in the invention according to claim 2, the electronic cooling element in the dehumidifying means is also used for keeping the inside of the camera housing warm.

According to the present invention, the moisture inside the camera housing is removed by the electronic cooling element, and the fogging of the front glass is removed or prevented. Therefore, the dehumidifier can be simplified, downsized, and reduced in cost. And power consumption can be reduced. Also, by using the electric cooling element to keep the inside of the camera housing warm,
A special heater such as a conventional nichrome wire heater or an infrared lamp as in the related art is not required, and prevention of fogging of the front glass and heat retention in the camera housing can be realized with a simple and inexpensive device and with low power consumption.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a camera housing according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an external view showing an embodiment of a camera platform provided with a camera housing to which the present invention is applied. The camera platform 10 shown in FIG. 1 includes a camera housing 14 that houses a television camera (hereinafter simply referred to as a camera) (not shown), and a camera platform body 16 that pans and tilts the camera together with the camera housing 14.

The camera housing 14 is cantilevered by a tilt shaft (not shown) extending from the camera platform main body 16, and the tilt shaft is driven to rotate by a tilt motor built in the camera platform main body 16. As a result, the internal camera is tilted together with the camera housing 14. The pan head body 16 is supported by a pan shaft 19 fixed on a mounting table (not shown). The pan head body 16 is driven to rotate by a built-in pan motor around the pan shaft 19 to thereby provide a camera housing. The camera inside pans with 14.

A transparent front glass 18 is provided on the front surface of the camera housing 14.
The camera housed in the camera can take a picture outside the camera housing 14 through the front glass 18. Further, a dehumidifier for removing and preventing fogging of the front glass 18 is mounted on the camera housing 14 as described later.

The camera platform 10 is connected to the camera platform controller 12 via a communication line such as a dedicated line or a public line, and a user operates an operation member (not shown) of the camera platform controller 12 to thereby control the camera platform 10. , The on / off of the dehumidifying device of the camera housing 14, and the like.

Next, the dehumidifying device mounted on the camera housing 14 will be described. FIG. 2 is an internal layout diagram showing the inside of the camera housing 14 from above. As shown in FIG. 1, the camera housing 14 is entirely covered with a box-shaped casing 20, and a front glass 18 is provided on a front surface of the camera housing 14. Inside the camera housing 14, a camera body 22 is provided.
A camera including a camera lens 22 mounted on the camera body 22 is housed, and the camera is installed such that the front side of the camera lens 24 faces the front glass 18.

Inside the camera housing 14, a dehumidifier 26 utilizing an electronic cooling element is installed. In order to control the on / off of the dehumidifier 26, the front glass 1
A temperature sensor 30 for detecting the temperature of the
A dew condensation sensor 32 for detecting the dew condensation (cloudiness) of the camera housing 1 is installed on the periphery of the front glass 18.
A temperature sensor 34 for measuring the inside air temperature in 4 and a humidity sensor 36 for measuring the internal humidity are installed at predetermined positions.

FIG. 3 is an enlarged view of the dehumidifier 26. As shown in FIG. As shown in the figure, the dehumidifier 26 includes a Peltier module 40 and a heat sink 42. The Peltier module 40, as generally known,
And a N-type semiconductor connection pair (electro-cooling element) are electrically connected in series to form a unit. The element arrangement section 4 between two insulating heat transfer plates (ceramics or the like) 40A, 40B
At 0C, P-type and N-type semiconductor elements are alternately and electrically connected in series in a π shape or an inverted π shape. When the dehumidifier 26 is turned on, the Peltier module 40
DC current is supplied from the positive and negative electric wires 44A and 44B. Thus, one heat transfer plate 40A serves as a cooling surface (heat absorbing surface), and the other heat transfer plate 40B serves as a heat dissipation surface. At least the heat transfer plate 40A serving as a heat absorbing surface is the camera housing 1
4 is exposed in the air. On the other hand, the heat transfer plate 4 serving as a heat dissipation surface
A heat radiating plate 42 is bonded to OB with a heat conductive double-sided tape or the like so that the heat radiated from the heat conductive plate 40B is easily radiated into the air.

According to the dehumidifier 26 configured as described above, the dehumidifier 26 is turned on (hereinafter, the Peltier module 4).
0 is turned on), the heat transfer plate 40A of the Peltier module 40 is cooled, and the camera housing 1 is turned on.
The moisture in 4 is condensed on heat transfer plate 40A. As a result, the moisture in the air in the camera housing 14 is removed, and when the front glass 18 is clouded (condensed), the clouding is removed, and when it is not clouded, the clouding is prevented. .

When the Peltier module 40 is turned on, heat is released as a whole, so that the dehumidifier 26 can function not only as a dehumidifier but also as a heater. For example, in cold weather or the like, the air in the camera housing 14 can be kept warm and heated by turning on the Peltier module 40 to guarantee the operation of the camera.

It is to be noted that a camera housing generally known as a camera housing has a completely sealed inside from the outside air (sealed type) and a housing capable of intentionally introducing the outside air into the inside (outside air introduction type). However, in any case, it is effective to remove or prevent the dew condensation on the front glass 18 only by causing the moisture of the air in the camera housing 14 to condense on the heat absorbing surface of the Peltier module 40. Also,
In addition to simply causing the moisture absorption in the air to condense on the heat absorbing surface of the Peltier module 40, the condensed water droplets may be discharged to the outside of the camera housing 14. For example,
As shown in FIG. 4, the heat transfer plate 40 of the Peltier module 40
The dehumidifying device 26 is installed in the camera housing 14 so that A (heat absorbing surface) is in the vertical direction, and water droplets condensed on the heat transfer plate 40A are dropped. And the heat transfer plate 40A
A drain pipe 60 that receives water drops dropped from the camera housing 14 and discharges it to the outside of the camera housing 14 has a predetermined length (length that can correspond to the size of the Peltier module 40) in the depth direction of the paper formed on the casing 20 of the camera housing 14. It is inserted and arranged in the slit-shaped hole 62.

FIG. 5 shows the ON / OFF state of the Peltier module 40.
It is a control block diagram which performs an off control. In the figure, the CPU 50 controls on / off of the Peltier module 40 by turning on / off the supply of current to the Peltier module 40 by the driver 52. CPU5
0 is provided with a mode setting command selected by the user from the camera platform controller 12 (see FIG. 1), and this command controls on / off control of the Peltier module 40 between the manual mode and the auto mode. Is switched to. In the case of the manual mode, the user selects ON or OFF of the Peltier module 40 by a predetermined switch of the camera platform controller 12. Based on this selection, the pan head controller 12
A command is given to the PU 50, and the CPU 50 turns the Peltier module 40 on or off according to the command. On the other hand, in the case of the auto mode, the CPU 50
Based on the temperature signal from the temperature sensor 30 shown in FIG. 2, the condensation signal from the condensation sensor 32, the temperature signal from the temperature sensor 34, and the humidity signal from the humidity sensor 36,
On / off of the Peltier module 40 is automatically controlled.

That is, the CPU 50 detects the temperature of the front glass 18 based on the temperature signal from the temperature sensor 30 and detects the dew condensation on the front glass 18 based on the condensation signal from the dew sensor 32. Further, the humidity inside the camera housing 14 is detected based on the humidity signal from the humidity sensor 36. As a result, the Peltier module 40 is turned on when there is a possibility that dew condensation may occur on the front glass 18 or when dew condensation has already occurred. On the other hand, after turning on the Peltier module 40, if the dew condensation on the front glass 18 has been eliminated or if there is no longer any possibility of dew condensation, the Peltier module 40 is turned off.

The CPU 50 detects the temperature inside the camera housing 14 based on the temperature signal from the temperature sensor 34. Accordingly, when it is determined that the temperature inside the camera housing 14 needs to be increased (maintained at a certain temperature or higher) in order to secure or maintain the allowable operating temperature of the camera, the Peltier module 40 is turned on. On the other hand, if it is determined that it is not necessary to keep the inside air temperature in the camera housing 14 after turning on the Peltier module 40, the Peltier module 40 is turned off.

FIG. 6 shows the CPU 5 in the auto mode.
9 is a flowchart illustrating an example of a processing procedure of No. 0. First, the CPU 50 determines whether or not condensation has occurred on the front glass 18 based on the condensation signal acquired from the condensation sensor 32 (step S10). If YES is determined, the Peltier is removed to remove the condensation. Module 40
Is turned on (if it is already on, the on state is continued. The same applies hereinafter) (step S18). On the other hand, if the determination is NO, it is next determined whether or not the temperature of the front glass 18 is equal to or lower than a certain temperature based on the temperature signal acquired from the temperature sensor 30 (step S12). If the determination is YES, the Peltier module 40 is turned on to prevent condensation on the front glass 18 (step S1).
8). On the other hand, if the determination is NO, the camera housing 1 is then turned on by the temperature signal acquired from the temperature sensor 34.
Then, it is determined whether or not the inside air temperature in Step 4 is equal to or lower than a predetermined temperature (Step S14). If the determination is YES, the Peltier module 40 is turned on to secure or maintain the allowable operating temperature of the camera (step S18). On the other hand, NO
If it is determined that the humidity in the camera housing 14 is equal to or higher than a certain level, it is determined based on the humidity signal acquired from the humidity sensor 36 (step S15). if,
If the determination is YES, the Peltier module 40 is turned on to prevent condensation on the front glass 18 (step S18). On the other hand, if NO is determined, the above steps S10, S12, S14,
Since all the determinations in step S15 are NO, the Peltier module 40 is turned off (step S1).
6). The above-described determination processing (steps S10 to S15) and the on / off processing of the Peltier module 40 (steps S16 and S18) are repeatedly executed, and the on / off of the Peltier module 40 is automatically controlled according to the situation. I do. Step S12, step S1
In the determinations of step 4 and step S15, the temperature and humidity serving as determination criteria for switching the Peltier module 40 from off to on and for switching it from on to off may not be the same.

As described above, in the present embodiment, the temperature sensor 30 is used to remove or prevent fogging of the front glass 18.
Although the condensation sensor 32 and the humidity sensor 36 are provided, it is not always necessary to provide these three sensors. For example, only the temperature of the front glass 18 may be detected by the temperature sensor 30, and if there is a possibility that dew condensation may occur on the front glass 18, the Peltier module 40 may be turned on to surely prevent the front glass 18 from fogging. . Also,
The dew condensation sensor 32 may detect only the dew condensation on the front glass 18 and turn on the Peltier module 40 when the dew condensation occurs. Furthermore, only the humidity inside the camera housing 14 is detected by the humidity sensor 36, and when there is a possibility that dew condensation may occur on the front glass 18, the Peltier module 40 is turned on to surely prevent the front glass 18 from fogging. Good.

Further, in the present embodiment, the Peltier module 40 is used as a heater to secure or maintain the allowable operating temperature of the camera, but it is not always necessary to use it as a heater. Further, even when the Peltier module 40 is used as a heater, the temperature of the front glass 18 detected by the temperature sensor 30 can be used to maintain the temperature inside the camera housing 14 without installing the temperature sensor 34. It may be determined whether or not it is necessary to turn on. Conversely, the temperature sensor 3
Instead of 0, it may be determined whether or not the Peltier module 40 needs to be turned on in order to remove or prevent fogging of the front glass 18 based on the inside air temperature in the camera housing 14 detected by the temperature sensor 34. Good.

[0029]

As described above, according to the camera housing of the present invention, the moisture in the camera housing is removed by the electronic cooling element, and the fogging of the front glass is removed or prevented. Simplification, downsizing, and cost reduction can be achieved, and power consumption can be reduced. In addition, by using the electric cooling element also to keep the inside of the camera housing warm, a special heater such as a conventional nichrome wire heater or an infrared lamp becomes unnecessary, which prevents the front glass from fogging and prevents the inside of the camera housing from fogging. Can be realized with a simple and inexpensive device and low power consumption.

[Brief description of the drawings]

FIG. 1 is an external view showing an embodiment of a camera platform including a camera housing to which the present invention is applied.

FIG. 2 is an internal layout diagram showing the inside of the camera housing from above.

FIG. 3 is an enlarged view of the dehumidifier.

FIG. 4 is a diagram showing a configuration in a case where water removed by a dehumidifying device can be discharged to the outside of a camera housing.

FIG. 5 is a control block diagram for performing on / off control of a Peltier module.

FIG. 6 is a flowchart illustrating an example of a processing procedure of a CPU 50 in an auto mode.

[Explanation of symbols]

14 camera housing, 18 front glass, 22 camera body, 24 photographing lens, 26 dehumidifier, 30,
34: temperature sensor, 32: condensation sensor, 40: Peltier module, 40A, 40B: insulating heat transfer plate, 42: heat sink, 50: CPU

Claims (3)

[Claims] In a camera housing having a front glass attached to a front end of a camera facing a taking lens of a camera, moisture in the camera housing is dehumidified by dehumidifying means using an electronic cooling element. A camera housing characterized by removing or preventing fogging of a front glass. 2. A temperature detecting means for detecting a temperature of the front glass, a dew detecting means for detecting dew condensation on the front glass,
Or, provided with a humidity detecting means for detecting the humidity in the camera housing, the high and low of the temperature detected by the temperature detecting means, the presence or absence of condensation detected by the condensation detecting means, or,
2. The camera housing according to claim 1, wherein on / off of said electronic cooling element is automatically switched according to the level of humidity detected by said humidity detecting means. 3. The camera housing according to claim 1, wherein an electronic cooling element in said dehumidifying means is also used to keep the inside of said camera housing warm.