JP2008219610A - Image sensor cooled camera - Google Patents

Abstract

An imaging element cooling camera that prevents condensation on the surface of an imaging element in an imaging element cooling camera.
An image sensor in which a first housing part and a second housing part form a sealed space via an O-ring, and a cooling element cools an image sensor arranged in the sealed space. In the cooling camera 100, a first sealed chamber A formed on the surface side of the image sensor, a second sealed chamber B formed around the first sealed chamber, the first sealed chamber, and the second sealed chamber 100. First electromagnetic valves 18a and 18b for controlling ventilation with the sealed chamber, second electromagnetic valves 18c and 18c for controlling ventilation between the second sealed chamber and the outside, and from the first sealed chamber to the second sealed chamber. An image sensor cooled camera 100 including fans 21a and 21b for forcibly exhausting air.
[Selection] Figure 1

Description

  The present invention relates to an image sensor cooled camera capable of cooling an image sensor.

Conventionally, a cooling camera with a simple cooling structure that cools an image sensor has a structure in which a housing divided before and after the cooling camera is sealed through an O-ring to prevent intrusion of outside air and cool the image sensor. The thing of the structure which prevents the dew condensation on the image pick-up element surface and a cooling camera inside is known (for example, refer patent document 1).
JP-A-9-162379

  However, in the structure of the conventional cooling camera, a minute ventilation hole is formed in the O-ring due to expansion / contraction due to temperature change of the O-ring itself, and it is difficult to completely prevent water vapor from entering the sealed chamber. Water vapor that has entered the interior of the room condenses on the low temperature part of the Peltier element. The condensed water vapor evaporates again in the sealed chamber when the cooling camera is used and the cooling operation is stopped, and when the Peltier device starts to operate again to cool the image sensor again, the sealed chamber is sealed. There is a problem that the water vapor in the room is condensed on the surface of the imaging device cooled by the Peltier device.

  In order to solve the above-described problem, the present invention provides a first housing part and a second housing part that form a sealed space via an O-ring, and cools an image sensor disposed in the sealed space with a cooling element. In the image sensor cooling type camera, a first sealed chamber formed on the surface side of the image sensor, a second sealed chamber formed around the first sealed chamber, the first sealed chamber, and the second sealed chamber. A first solenoid valve that controls ventilation between the chamber, a second solenoid valve that controls ventilation between the second sealed chamber and the outside, and a fan that forcibly exhausts air in the second sealed chamber from the first sealed chamber; An image sensor cooling camera is provided.

  According to the present invention, in the image sensor cooling type camera, when the cooling operation of the camera is finished, water vapor in the sealed chamber is quickly exhausted, and when the cooling operation is started again, condensation on the surface of the image sensor is prevented. It is possible to provide an imaging element cooling type camera capable of performing

  An image sensor cooling camera according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional configuration diagram of an imaging element cooling camera according to an embodiment. FIG. 2 is an explanatory diagram of a dehumidified state of the first sealed chamber of the image sensor cooling camera according to the embodiment. FIG. 3 is an explanatory diagram of an exhausted state of sealed indoor air of the image sensor cooling camera according to the embodiment. FIG. 4 is a cross-sectional view of an image sensor cooling camera according to a modification of the present embodiment. In addition, the code | symbol which shows a member is mainly attached | subjected and demonstrated to FIG. 1, and description of another figure is abbreviate | omitted.

  In FIG. 1, an image sensor cooling type camera 100 (hereinafter simply referred to as a cooling camera) according to the present embodiment includes a first housing part 11a and a second housing part 11b fixed via an O-ring 24. 100 casings 11 are configured. The housing 11 is formed in a rectangular shape or a cylindrical shape.

  A camera mount 12 is fixed to the upper portion of the first housing portion 11a (upper side in FIG. 1) by a fixing member (not shown). A second optical filter 15 (for example, a parallel plate glass) is disposed between the camera mount 12 and the first housing portion 11a to prevent intrusion of outside air from the camera mount 12 side.

  An imaging element substrate 14 on which the imaging element 25 is supported is fixed to the first housing part 11a with a screw 30 below the first housing part 11a (lower side in FIG. 1). An opening is formed at the position of the image pickup element 25 on the image pickup element substrate 14, and the Peltier element 13 for cooling the image pickup element is in thermal contact with the back surface of the image pickup element 25 through the opening. The other surface of the Peltier element 13 is in thermal contact with the inner surface of the bottom radiator 22 of the second housing portion 11b.

  An opening is formed in the first housing portion 11a on the imaging surface side of the image sensor 25, and light incident from the camera mount 12 side is imaged by the image sensor 25.

  A packing 23 is disposed in a non-imaging region on the surface cover glass of the image sensor 25, and the packing 23 is pressed against the first housing portion 11a to block air flow.

  A first optical filter 16 (for example, an infrared cut filter) is fixed with a screw 33 via a packing 31 above the space on the surface cover glass side of the image sensor 25.

  A first sealed chamber A is formed by the surface cover glass of the image sensor 25 and the first optical filter 16. Further, the second sealed chamber B is formed in the space formed by the first housing part 11a, the second optical filter 15, and the first optical filter 16 in the space formed by the first housing part 11a and the second housing part 11b. A third sealed chamber C is formed.

  Openings 34, 34 communicating with the second sealed chamber B are formed on the side wall of the first sealed chamber A of the first housing portion 11 a, and dustproof filters 17 b, 17 b are provided on the second sealed chamber side of the openings 34, 34. Solenoid valves 18a and 18a are arranged via O-rings 19a and 19a. The electromagnetic valves 18a and 18a control the air flow between the first sealed chamber A and the second sealed chamber B.

  The second sealed chamber B and the third sealed chamber C are coupled to each other through openings 36 and 36 through dust-proof filters 17a and 17a, and air circulation between the second sealed chamber B and the third sealed chamber C is ensured. This prevents dust and the like from entering the second sealed chamber B into the third sealed chamber C.

  Openings 37 and 37 for introducing outside air are formed on the camera mount 12 mounting side of the first housing portion 11a, and O-rings 19c and 19c are provided on the second sealed chamber B side of the openings 37 and 37, respectively. Solenoid valves 18c and 18c are provided.

  Further, openings 38, 38 for discharging air from the second sealed chamber B are formed in the vicinity of the radiator 22 of the second housing portion 11b, and on the second sealed chamber B side of the openings 38, 38, Solenoid valves 18b and 18b are provided via O-rings 19b and 19b.

  Fans 21a and 21b are provided on the side surface of the second housing 11b in the vicinity of the radiator 22. Note that the radiator 22 has a sufficient heat radiation effect without sending air by the fans 21a and 21b.

  Further, Peltier elements 20a and 20b for dehumidification are disposed in the vicinity of the Peltier element 13 that cools the imaging element 25 disposed inside the second sealed chamber B of the radiator 22.

  The cooling camera 100 is formed as described above.

  Next, the cooling operation of the cooling camera 100 will be described.

(Operation before starting image sensor cooling)
In this cooling type camera 100, before starting the cooling of the image sensor 25 by the Peltier device 13, a pre-operation for preventing condensation on the surface of the image sensor 25 is performed.

  As shown in FIG. 2, the pre-operation is performed by closing the electromagnetic valves 18b, 18b, 18c, and 18c and blocking the inflow of outside air, then opening the electromagnetic valves 18a and 18a, and the first sealed chamber A and the second sealed chamber. B air circulation is secured. Thereafter, the dehumidifying Peltier elements 20a and 20b are operated and cooled, and the dehumidifying Peltier elements 20a and 20b are supplied with water vapor from the first sealed chamber A, the second sealed chamber B, and the third sealed chamber C, respectively. Dew condensation is performed on 20a and 20b to dehumidify and dry the space from the first sealed chamber A to the third sealed chamber C.

  After the first sealed chamber A to the third sealed chamber C are sufficiently dehumidified and dried, the solenoid valves 18a and 18a are closed to block the air flow between the first sealed chamber A and the second sealed chamber B.

(Image sensor cooling, shooting operation)
Thereafter, as shown in FIG. 1, the Peltier element 13 that is in thermal contact with the image sensor 25 is operated with all the solenoid valves 18 a, 18 a, 18 b, 18 b, 18 c, and 18 c closed, and the image sensor 25 , The thermal noise of the image sensor 25 is reduced, and image acquisition by the image sensor 25 is executed.

(Operation after shooting)
After the desired photographing by the cooling camera 100 is finished, as shown in FIG. 3, the operation of the Peltier element 13 and the dehumidifying Peltier elements 20a and 20b is stopped and the electromagnetic valves 18a, 18a, 18b, 18b, 18c, The air in the third sealed chamber C is forcibly exhausted from the first sealed chamber A by opening all 18c and further operating the fans 21a and 21b.

  At this time, air from the first sealed chamber A to the third sealed chamber C is exhausted from the openings 38 and 38 by the fans 21a and 21b, and outside air is introduced from the openings 37 and 37. By this exhaust, the moisture condensed on the Peltier element 13 and the dehumidifying Peltier elements 20a, 20b evaporates and is exhausted together with the air.

  As described above, the air is forcedly exhausted by the fans 21a and 21b while introducing the outside air from the openings 37 and 37, so that the air in the third sealed chamber C can be efficiently exhausted from the first sealed chamber A, and the Peltier element 13 and Moisture condensed on the dehumidifying Peltier elements 20a and 20b can be exhausted sufficiently.

  In order to prevent intrusion of dust and water vapor after sufficiently exhausting and replacing the air in the first sealed chamber A to the third sealed chamber C with outside air, all the solenoid valves 18a, 18a, 18b, 18b, 18c , 18c.

  As described above, in the cooling camera 100 according to the present embodiment, by repeating FIG. 2 → FIG. 1 → FIG. 3 (→ FIG. 2...), Condensation on the surface of the cover glass of the image sensor 25 during cooling is prevented. Thus, it is possible to obtain a good image in which the thermal noise of the image sensor 25 is suppressed. In addition, this makes it possible to draw out the maximum capacity of the cooling mechanism constituted by the Peltier element 13 and the radiator 22, and to cool the imaging element to a lower temperature without limiting the cooling temperature.

"Modification of the first embodiment"
FIG. 4 is a modification of the first embodiment. 1 to 3 are referred to by the reference numerals in FIG. 1 and the description thereof is omitted. In this modification, in order to increase the heat dissipation efficiency of the radiator 22, the fan 21a, 21b forcibly blows air to the radiator 22 to increase the heat dissipation efficiency.

  Outside air inlets 39, 39 are provided in the vicinity of the fans 21a, 21b of the second housing portion 11b, and electromagnetic valves 27a used for switching outside air introduction and forced ventilation from the first sealed chamber A to the third sealed chamber C, 27b is arranged via O-rings 26a and 26b. As shown in FIG. 3, when the air from the first sealed chamber A to the third sealed chamber C is forcibly exhausted by the fans 21a and 21b, the openings 39 and 39 are closed by the electromagnetic valves 27a and 27b. The air in the third sealed chamber C is exhausted efficiently.

  On the other hand, when the radiator 22 is cooled to increase the cooling efficiency of the Peltier element 13 and the dehumidifying Peltier elements 20a and 20b, the electromagnetic valves 27a and 27b are opened, and the outside air is supplied to the fan 21a through the outside air inlets 39 and 39. , 21b can be positively introduced and sprayed onto the radiator 22. As a result, the heat dissipation efficiency of the radiator 22 is improved, and the imaging element 25 can be better cooled by the Peltier element 13. Furthermore, it is not necessary to shift the cooling operation of the Peltier element 13 and the photographing timing of the image sensor 25 as in the prior art.

  As described above, according to the present embodiment, even if the O-ring 24 that is a sealed chamber forming component has deteriorated over time, the front side (the cover glass side) of the image sensor 25 that is important for photographing is incorporated. By having the second sealed chamber B and the third sealed chamber C formed so as to surround the outside of the one sealed chamber A, the environmental change of the first sealed chamber A can be mitigated.

  Further, the first sealed chamber A is in a dry state, and the second sealed chamber B is kept in a dry state by the operating dehumidifying Peltier elements 20a and 20b. In this way, obstruction factors such as condensation can be removed.

  Further, after the photographing is finished, all the electromagnetic valves 18a to 18c are opened to allow ventilation with the outside air, and the fan is operated to quickly exhaust the water vapor accumulated in the first sealed chamber A to the third sealed chamber C. it can. Then, the water vapor is not accumulated from the first sealed chamber A to the inside of the third sealed chamber C by returning to the first operation after the steam exhaust and photographing. According to this mechanism, the inside of the first sealed chamber A to the third sealed chamber C can be constantly kept dry, so that the image sensor 25 can be further cooled to a low temperature, and the darkness of the image sensor 25 can be reduced. Current noise can be reduced.

  In addition, the first sealed chamber A to the third sealed chamber C can be ventilated with the outside air by opening and closing the electromagnetic valves 18a to 18c, and the exhaust of water vapor accumulated in the inside is accelerated. Further, by operating the exhaust fans 21a and 21b outside the electromagnetic valves 18c and 18c, the steam exhaust becomes faster. In addition, by operating the fans 21a and 21b to increase the heat dissipation efficiency of the radiator 22, the image sensor 25 can be cooled to a lower temperature.

  In addition, this mechanism keeps the dry state well and the image pickup device 25 reaches a low temperature, so that the performance of a cooled camera of the type in which the image pickup device 25 is vacuum-sealed can be made inexpensive.

  In the above-described embodiment, it is preferable to dispose a dustproof filter from the opening 37 to the opening 38 in order to prevent intrusion of dust or the like when introducing outside air.

  Further, the above-described embodiment is merely an example, and is not limited to the above-described configuration or shape, and can be appropriately modified and changed within the scope of the present invention.

It is a section schematic structure figure of an image sensor cooling type camera concerning an embodiment. Explanatory drawing of the dehumidification state of the 1st airtight chamber of the image pick-up element cooling type camera which concerns on embodiment. Explanatory drawing of the exhaust state of the sealed room air of the image pick-up element cooling type camera which concerns on embodiment. Sectional drawing of the modification of this Embodiment is shown.

Explanation of symbols

11a First housing 11b Second housing 12 Camera mount 13 Imaging element cooling Peltier element 14 Imaging element substrate 15 Second optical filter 16 First optical filter 17a, 17b Dustproof filter 18a, 18b, 18c, 27a, 27b Electromagnetic valve 19a , 19b, 19c, 26a, 26b O-rings 20a, 20b Dehumidifying Peltier elements 21a, 21b Exhaust fans 22 Radiators 23 Packing 25 Imaging elements 100 Imaging element cooling type camera

Claims (6)

In the imaging device cooling type camera in which the first housing portion and the second housing portion form a sealed space via an O-ring, and the imaging device disposed in the sealed space is cooled by a cooling device.
A first sealed chamber formed on the surface side of the image sensor;
A second sealed chamber formed around the first sealed chamber;
A first solenoid valve that controls ventilation between the first sealed chamber and the second sealed chamber;
A second solenoid valve for controlling ventilation between the second sealed chamber and the outside;
A fan for forcibly exhausting air in the second sealed chamber from the first sealed chamber;
An image pickup element cooling type camera comprising: The first solenoid valve is controlled so as to open a passage between the first sealed chamber and the second sealed chamber, and the second solenoid valve is closed so as to close a passage between the second sealed chamber and the outside. Dehumidification control processing to control and then actuate the cooling element to dehumidify the sealed space;
After the dehumidification control process, the cooling control process of closing the first electromagnetic valve and cooling the imaging element by the cooling element while maintaining the closing of the second electromagnetic valve;
After the cooling process, an imaging control process for operating and imaging the image sensor;
Control for performing forced exhaust control processing for opening the first electromagnetic valve and the second electromagnetic valve and operating the fan to introduce gas from the outside into the sealed space after the imaging control processing The imaging device cooling camera according to claim 1, further comprising a processing unit.   The imaging element cooling camera according to claim 1, further comprising a dehumidifying cooling element in the second sealed chamber. A third sealed chamber provided on the light incident side of the first sealed chamber is provided, and a dustproof filter is disposed in a vent hole between the first sealed chamber and the second sealed chamber. Item 4. The imaging element cooling camera according to any one of Items 1 to 3.   5. The image sensor cooled camera according to claim 1, wherein a dustproof filter is disposed in a vent hole between the second sealed chamber and the third sealed chamber. A third solenoid valve for controlling ventilation with the outside world;
The said 3rd solenoid valve is open | released when the said fan cools the heat radiator of the said cooling element and the said cold element for dehumidification, It introduce | transduces external air, It is any one of Claim 1 to 5 characterized by the above-mentioned. The imaging device cooling camera according to 1.

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