JPH022760B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention provides a method for cooling an infrared detector mounted on an artificial satellite to prevent outgas from adhering to the infrared incident window of the detector, which would inhibit the function of the detector. It concerns the plate structure.

(b) Technical background Infrared detectors for infrared cameras mounted on recent resource exploration satellites use photon-type detection elements made of multicomponent semiconductors such as HgCdTe. Although these have high sensitivity and fast response speed, if the optical path of infrared rays is obstructed by outgas, the high-level observation reliability of the detector will be immediately lost. Therefore, there is a strong demand for the development of a radiation cooler that does not allow outgas, which is a factor that obstructs the optical path of the infrared rays, to adhere to the infrared ray entrance window of the detector and has an excellent cooling function.

(c) Problems with the conventional technology Figure 1 is a diagram for explaining the configuration of a radiation cooler and the conventional cooling plate structure, where a is a side sectional view and b is the conventional cooling plate structure around an infrared detector. FIG. In the figure, 1 is the satellite body, 2 is the satellite side, 3 is the earth, 4 is infrared, 5 is mirror, 6 is infrared detector, 7 is infrared incidence window of the detector, 8 is detector fixing plate, 9 is cooling plate, 9' is the heat radiation surface, 10
1 is a gas intake hole, 11 is a gas discharge hole, 15 is a reflection plate, 16 is a shield plate, 20 is an outgas, 21
2 indicates a heat insulating material, and 25 indicates a screw.

As shown in FIG. 1, the radiation cooler 40 is mounted on one side 2 of the satellite main body 1, and directs infrared rays 4 from the earth 3, which is an object, through a mirror 5 provided on the satellite main body 1, to the vertical direction of the earth. An infrared detector 6 that receives light in the direction of arrow X perpendicular to the line and a detector fixing plate 8
A cooling plate 9 and the outer space 50, with the surface on which the detector 6 is attached by screws 25 facing the satellite main body 1 side, and the opposite surface facing the outer space 50 side as a heat dissipation surface 9'. For example, it includes a shield plate 16 that shields the first earth radiation 25 incident in the direction of the arrow F, and a reflector plate 15 that reflects the second earth radiation 30 incident in the direction of the arrow G and radiates it in the direction of the arrow G'. It consists of The cooling plate 9 contains outgas 20 generated from the heat insulating material 21 filled in the space formed by the satellite body 1, the shield plate 16 of the radiation cooler 40, the reflector plate 15, and the satellite side surface 2. A gas suction hole 10 and a gas discharge hole 11 for releasing gas to the outer space 50 side.
The outgas 20 in the direction of arrow A first contacts the infrared incident window 7 of the detector 6, and then is released from the direction of arrow A' through the gas suction holes 10 provided above and below the cooling plate 9. It is structured so that it is ejected from the hole 11 in the direction of arrow B, that is, toward the outer space 50 side. However, in this structure, the radiation path of the outgas 20, which is synthesized from the gas intruding from the satellite main body 1 side where the standard temperature is maintained at 20°C (293°) and the gas generated from the insulation material 21, is complicated and has a long distance. Since the temperature is long, a large amount of the outgas 20 adheres to the infrared entrance window 7 of the infrared detector 6, which is in a vacuum and ultra-low temperature (100°) environment, causing a freezing phenomenon and interfering with the infrared rays 4 entering the detector 6. As a result, the transmittance deteriorates and the observation reliability of the detector 6 is reduced.

(d) Purpose of the Invention The present invention has been made to correct the above-mentioned conventional drawbacks, and is to provide an outgas that inhibits outgas from adhering to the infrared incidence window of the infrared detector, which impairs the reliability of the infrared detector. The purpose of this invention is to provide a radiation cooler having a bypass structure.

(e) Structure of the Invention According to the present invention, the object is to provide an infrared detector which is mounted on an artificial satellite and receives infrared rays emitted from an object, and an infrared detector with the surface on which the detector is attached facing the satellite side. An outgas bypass structure is attached to the cooling plate of the radiation cooler comprising a cooling plate facing toward the outer space side with the opposite surface as a heat dissipation surface, the outgas bypass structure leading to the outer space side through the periphery of the detector on the satellite side. This is achieved by providing a radiant cooler characterized by:

(f) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a perspective view showing a cooling plate structure around an infrared detector according to the present invention. In this figure, the same parts as in the previous figure are given the same reference numerals.
Reference numeral 8 indicates a notch provided in the detector fixing plate, and reference numeral 19 indicates a bypass hole. Note that the present invention is an infrared detector 6.
Since this is related to improvements in the structure of the fixing plate 8 and the mounting part of the detector 6 on the cooling plate 9, we will focus our explanation on these and omit the explanation of the overall structure that overlaps with that in Figure 1 as appropriate. do.

As shown in FIG. 2, in the radiation cooler of the present invention, a notch 18 is provided in the detector fixing plate 8 for fixing the infrared detector 6 to the cooling plate 9, and a notch 18 is provided in the detector fixing plate 8 of the cooling plate 9. A feature is that a rectangular opening is formed at the bottom so that a partial bypass hole 19 corresponding to the notch 18 is formed when the fixing plate is attached.
Due to this feature, that is, the bypass hole 19 that passes through the circumference of the detector to the outer space side, the outgas 20 in the direction of arrow A takes a detour route shown by arrow A' to the gas suction hole 10 provided in the cooling plate 9. Therefore, the infrared rays go straight in the direction of arrow A'' without any stagnation in the vicinity of the infrared entrance window 7, and are smoothly discharged from the gas discharge hole 11 in the direction of arrow B through the bypass hole 19. The outgas 20 that adheres to the infrared ray entrance window 7 of the detector 6 and freezes and obstructs the transmission of the infrared rays 4 is significantly reduced, and the reliability of infrared observation of the detector 6 is guaranteed over a long period of time.

(g) Effects of the Invention As explained in detail above, the radiation cooler of the present invention removes outgas that adheres to the infrared incidence window of the infrared detector and freezes and obstructs the function of the detector at the detector mounting portion of the cooling plate. This has a great effect in that it can be discharged accurately by the bypass structure provided around the periphery.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the configuration of a radiation cooler and a conventional cooling plate structure, and FIG. 2 is a diagram for explaining the cooling plate structure of the present invention. In the drawing, 1 is the satellite body, 2 is the satellite side, and 3
is the earth, 4 is the infrared rays, 5 is the mirror, 6 is the infrared detector, 7 is the infrared incidence window, 8 is the detector fixing plate, 9
10 is a cooling plate, 10 is a gas intake hole, 11 is a gas discharge hole, 15 is a reflection plate, 16 is a shield plate, 18 is a notch provided in the detector fixing plate, 19 is a bypass hole, 2
0 is an outgas, 21 is a heat insulating material, 25 is a first earth radiation, 30 is a second earth radiation, 47 is a radiation cooling equipped with an infrared detector 6, a cooling plate 9, a reflector 15, a shield plate 16, and a heat insulating material 21. 50 represents outer space.

Claims (1)

[Claims] 1. An infrared detector mounted on an artificial satellite that receives infrared rays emitted from a target, and a cooling plate with the surface on which the detector is attached facing the satellite and the opposite surface facing the outer space side as a heat dissipation surface. 1. A radiation cooler comprising: an outgas bypass structure connected to the cooling plate of the radiation cooler, which communicates to the outer space side through a peripheral portion of the detector on the satellite side.