JPH04349099A - Radiative cooling device - Google Patents

Abstract

PURPOSE:To allow a radiative cooler to respond both to a structure, in which inert gas flows uncontrolled, and a simple structure to contain inert gas sealedly by constructing the periphery of an infrared sensor in an airtight structure, filling inside of this airtight structure with inert gas or a dried gas at any appropriate timing, and sealing the place with blind caps through O-ring packing. CONSTITUTION:A radiative cooler as per invention is to cool an infrared sensor 11. The periphery of the infrared sensor 11 is made in airtight structure using O-rings 17-25, and inside of the airtight structure is filled with an inert gas or dried gas at any appropriate timing, wherein the airtightness is maintained by sealing the area with blind caps 14A, 14B through O-ring packing 26. Thereby dry gas can be kept for a long period of time certainly to purge the moisture, the infrared sensor be produced from deterioration on the ground, and consumption of the inert gas or dried gas be lessened.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a radiation cooler, and is particularly used for cooling infrared detectors mounted on artificial satellites, and is used to prevent a decrease in the detection sensitivity of infrared detectors during tests of the ground environment before launch. This invention relates to an improved radiant cooler.

0002

2. Description of the Related Art Photon detectors for Hg, Cd, Te, etc. are used in infrared detectors for infrared cameras mounted on recent earth resource exploration satellites.

Conventionally, this type of detector element suffers from performance deterioration due to humidity in the air. Furthermore, since the adhesion of contaminants during performance confirmation tests on the ground can lead to a decrease in sensitivity, an inert gas (such as dry nitrogen gas) is flowed in one direction to cover the area around the infrared detector in the radiant cooler. The structure was designed to prevent the infrared detector from coming into direct contact with air or contaminants by using a so-called dripping system.

[0004] There is also a method of placing the infrared detector in a sealed glass container and sealing it in a vacuum, but this method is difficult because glass is susceptible to vibration and impact during launch and there is a possibility of cracking due to heat shrinkage, etc. It wasn't used.

[0005]

Problems to be Solved by the Invention In the conventional radiation cooler described above, the structure in which inert gas is dripped has the following drawbacks.

(1) If the period until launch is long, a large amount of inert gas is required.

(2) In system tests and the like performed after installation in an artificial satellite, the flow-through work is significantly restricted.

(3) Unevenness occurs in the flow of the inert gas, making it impossible to cover it uniformly.

The object of the present invention is to provide a radiation cooler that can accommodate both the inert gas dripping structure for infrared detector unit tests and the simple structure for sealing inert gas in the final system test. It is about providing.

0010

[Means for Solving the Problems] The radiation cooler of the present invention includes:
In a radiation cooler that cools an infrared detector etc. mounted on an artificial satellite, the area around the infrared detector is made into an airtight structure,
After filling the inside of the airtight structure with inert gas or dry gas at any time, it is sealed with a blind cap via an O-ring packing to maintain confidentiality.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of one embodiment of the present invention. In the embodiment of FIG. 1, the parts added to the structure of the conventional example are two exhaust ports 13A, 13B, removable blind caps 14A, 14B, and internal spaces 27A, 27B formed with a double structure. In order to achieve complete airtightness, O-ring packings 17 to 26 are provided at 10 locations to create a hermetic state. Furthermore, by removing the blind caps 14A and 14B, the inert gas can be made to flow in one direction from the exhaust port 13A to the exhaust port 13B during a unit test.

Next, the structure and operation of this embodiment will be explained. The infrared detector 11 is mounted on a cooling plate 5 supported by an insulating ring 4. The cooling plate 5 is attached to the intermediate cooling plate 3, and the intermediate cooling plate 3 is attached to the heat insulating ring 4. In addition, the heat insulating ring 6 is connected to the exhaust ports 13A and 13B.
is fixed on the base plate 7 to which is attached. A method for cooling the infrared detector 11 to an operating temperature of about 100K is to connect the heat conduction plate 1 to a cooling source of about 90K,
It is cooled by heat conduction. Furthermore, in order to reduce radiant heat leakage in the 100K temperature portion, an intermediate cooling plate 3 of about 160K is provided between the heat insulating ring 6 and the normal temperature stage. Similar to the cooling plate 5, the intermediate cooling plate 3 is cooled to a predetermined temperature (approximately 160K) by connecting the heat conduction plate 2 to an external cooling source. In this state, if there is air containing moisture inside, the surface of the infrared detector 11 will be 100K, 1
Dew condensation occurs on the 60K surface and the performance of the infrared detector 11 deteriorates. The infrared rays 10 pass through the germanium lens 8, are detected by the infrared detector 11, and the signals are outputted to the outside via the flexible printed circuit board 12. The flexible flint substrate 12 is integrally molded into a sandwich with a donut-shaped airtight ring 15 to maintain airtightness. O-ring packings 17 to 26 are inserted into the mounting surface of each component, and exhaust ports 13A and 13 are inserted into the end surface of the base plate 7.
If B is provided at two locations and dry gas is injected from one side and the other is left open, the interior will be filled with dry gas and the aforementioned dew condensation can be removed. And both exhaust ports 13
If you insert the O-ring packing 26 into the inlets of A and 13B and attach the blind caps 14A and 14B, the inside will be as follows.
A state filled with dry gas is maintained. The internal pressure is the same as the external atmospheric pressure, and the pressure difference prevents dry gas from permeating through the O-ring packing 26.

[0014]

As explained above, the present invention has a structure in which the area around the infrared detector is made airtight, and the inside of the airtight structure can be filled with inert gas or dry gas at any time during the final system test to maintain the airtightness. Therefore, it has the following effects.

(1) It is possible to keep dry gas reliably for a long period of time and wipe out moisture, and there is no deterioration of the infrared detector on the ground.

(2) The consumption of inert gas or drying gas is small, making it economical.

(3) It becomes easier to integrate into artificial satellites,
Moreover, it is possible to eliminate the work process of pouring inert gas into the internal space after assembly.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a radiation cooler according to an embodiment of the present invention.

[Explanation of symbols]

1 Heat conduction plate 2 Heat conduction plate 3 Intermediate cooling plate 4 Heat insulation ring 5 Cooling plate 6 Heat insulation ring 7 Space plate 8 Germanium lens 9 Germanium lens 10 Infrared ray 11 Infrared detector 12 Flexible printed circuit board 13A, 13B
Exhaust port 14 Blind cap 15
Airtight ring 16 Filters 17 to 26 O-ring packing 27 Internal space 28 Mounting plate

Claims (2)

[Claims] 1. A radiation cooler for cooling an infrared detector etc. mounted on an artificial satellite, wherein the area around the infrared detector is made into an airtight structure, and an inert gas or dry gas is added to the inside of the airtight structure at any time. A radiation cooler characterized in that after being filled with gas, it is sealed with a blind cap via an O-ring packing to maintain confidentiality. 2. Inert gas or dry air is injected from one of two predetermined locations of the airtight structure and discharged from the other.
2. The radiant cooler according to claim 1, further comprising a structure in which the blind cap is attached to the inlet of the exhaust port to seal it.