Infrared camera extinction array assembly based on 120K deep hypothermia space and light shield

Abstract

The invention relates to an extinction array assembly and a light shield based on a 120K deep hypothermia space infrared camera, the extinction array assembly comprises an extinction array plate and a heat conduction layer, the extinction array plate comprises an extinction sheet and a substrate, and the heat conduction layer comprises indium foil and silicone grease. The lens hood comprises an extinction array assembly, a lens hood body, cold finger interfaces, cold finger clamps and a spherical hinge assembly. The lens hood of the deep hypothermia space infrared camera is in contact with a lens cold finger through the two cold finger interfaces. The working temperature of 120 K of the light shield is guaranteed, and four extinction array assemblies are fixedly connected with the inner surface of the light shield. The infrared radiation in the extinction array is primarily absorbed through the indium foil; the heat-conducting silicone grease is used for further absorption, the heat absorption function is achieved, the heat-conducting silicone grease and the light shield body jointly achieve absorption of infrared radiation in four directions, and accurate heat insulation is conducted through a spherical hinge structure and a fixing point.

Description

Technical Field

[0001] The invention belongs to the field of optical-mechanical structures of space optical remote sensors, and relates to an extinction array component and a light shield based on a 120K deep cryogenic space infrared camera. Background Art

[0002] As the resolution of remote sensing satellites increases, the demand for satellite imaging quality is getting higher and higher. The infrared radiation generated by the peripheral components of the onboard field of view (communication antennas, solar panels, thrust engines, etc.) has an increasingly significant impact on the imaging quality. Stray light suppression has become a necessary measure to ensure imaging quality. The sunshade and extinction array device are the core key components of modern optical systems. Their body temperature range and stray light suppression capabilities determine whether the performance indicators of the entire optical system can meet the design indicators.

[0003] In order to avoid too many invalid pixels in the imaging quality under the influence of stray light, it is often necessary to add extinction structures (such as extinction honeycombs, extinction black paint, etc.) to the sunshade. However, on components with close distance and strong diffuse reflection, such as other payloads on the satellite, too many on-board components may generate too much stray light, which will lead to the reduction of imaging quality of the optical path system. In order to improve the traditional extinction system (combination of extinction honeycombs and extinction black paint) that has poor ability to suppress stray light of on-board components, it is necessary to develop a new high-performance extinction device to meet the technical requirements of comprehensively controlling stray light and maximum field of view under the influence of stray light under different incident angles. The traditional extinction methods can be mainly divided into two types: extinction honeycombs and extinction black paint. The principle is to absorb stray light and then convert it into infrared radiation. This type of extinction method is related to the spectrum band, and the radiation generated in the infrared detection spectrum band may be too large; when the radiation of the sunshade itself far exceeds the refrigeration capacity, the imaging quality of the deep cryogenic space infrared camera will deteriorate as the temperature of the sunshade rises. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the insufficient ability of existing deep cryogenic space infrared camera hood extinction technology, especially the infrared stray light suppression capability of on-board components, and propose an extinction array assembly and hood based on a 120K deep cryogenic space infrared camera, which is conducive to meeting the shading requirements of complex environment applications such as solar stray light, earth stray light, and on-board component stray light, and the overall structure is simple and the utilization rate is high.

[0005] The solution of the present invention is:

[0006] A 120K deep cryogenic space infrared camera extinction array assembly, comprising an extinction array board and a heat-conducting layer, wherein the extinction array board comprises an extinction sheet and a substrate, and the heat-conducting layer comprises indium foil and silicone grease;

[0007] A plurality of matting sheets are arranged in parallel on the upper surface of a substrate at equal intervals, a layer of silicone grease is coated on the lower surface of the substrate, and an indium foil is attached to the lower surface of the silicone grease;

[0008] After the extinction array component is formed, the whole is treated with a chemical gold plating process, the solar absorption ratio is 0.3±0.05, and the infrared emissivity is ≤0.1.

[0009] Preferably, the height and spacing of the matte sheets are determined according to the angle requirement of the secondary diffuse reflection light.

[0010] Preferably, it comprises a light shield body, a cold finger interface, a cold finger clamp, a ball joint assembly and the light extinction array assembly according to claim 1;

[0011] Taking the symmetry axis of the light shield as a reference, cold finger interfaces are symmetrically installed on the left and right sides of the light shield body, and the cold finger interfaces are used to connect cold fingers;

[0012] Ball hinge assemblies are symmetrically installed on the left and right sides of the sunshade body, and the ball hinge assemblies are used to be fixedly connected to the sunshade support frame;

[0013] Cold finger clamps are symmetrically installed on the left and right sides of the hood body to fix the cold finger belt;

[0014] The inner wall of the light shield body is provided with extinction array components around the circumference, and the indium foil of the extinction array components is in close contact with the inner wall surface of the light shield body;

[0015] The surface of the light shield body is processed by chemical gold plating after being machined and formed.

[0016] Preferably, there are six ball joint assemblies in total, with three installed on each of the left and right sides of the sunshade body.

[0017] Preferably, the outer surface of the light shield body is provided with a cold finger interface, a cold finger clamp, and a ball joint assembly mounting hole, and the inner wall of the light shield body is processed with a light extinction array assembly mounting hole in an area away from the light opening.

[0018] Preferably, the diameters of the cold finger interface mounting hole, the cold finger clamp mounting hole, the ball joint assembly mounting hole, and the extinction array assembly mounting hole are 3 to 5 mm.

[0019] Preferably, the light shield body is made of aluminum alloy.

[0020] Preferably, the effective light aperture of the light shield is ≥200 mm×200 mm.

[0021] The beneficial effects of the present invention compared with the prior art are:

[0022] (1) In order to improve the insufficient ability of the traditional extinction system (combination of extinction honeycomb and extinction black paint) to suppress stray light of on-board components, the present invention adopts an extinction array assembly, which has a simple structure and high space utilization. The gold plating process is combined to improve the emissivity, and a cold finger interface, a ball joint assembly, and a cold finger clamp are left on the light shield, thereby enhancing the high thermal conductivity, strong mechanical properties, and high machining performance of the deep low temperature space infrared camera light shield, improving the service life of the light shield, and expanding the application field of the light shield.

[0023] (2) The deep cryogenic space infrared camera hood at a rated temperature of 120K can achieve the ability to suppress stray light in the three spectral bands of short-wave infrared, medium-wave infrared and long-wave infrared; this product can be used to eliminate stray light of equipment and is suitable for remote sensing optical fields such as stray light suppression of large-aperture optical remote sensing cameras. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the assembly of the 120K deep cryogenic space infrared camera light shield of the present invention;

[0025] Figure 2 It is a schematic diagram of the internal structure of the extinction array assembly of the present invention;

[0026] Figure 3 It is a schematic diagram of the structure of the sunshade body of the present invention;

[0027] Figure 4 is a schematic diagram of a ball joint assembly of the present invention;

[0028] The reference numerals in the figure are: 1- matt array assembly, 2- light shield body, 3- cold finger clamp, 4- cold finger interface, 5- ball joint assembly, 6- base plate, 7- matt sheet. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] like Figure 1-3 As shown, the present invention is based on a 120K deep cryogenic space infrared camera extinction array assembly 1 in which an extinction array plate and a heat-conducting layer are provided, and the heat-conducting layer is composed of indium foil and silicone grease.

[0031] The extinction array plate includes an extinction sheet 7 and a substrate 6. The height and spacing of the extinction sheets 7 are set according to the angle requirements of the secondary diffuse reflection light, and are arranged in parallel on the upper surface of the substrate 6. The number of the extinction sheets 7 can be adjusted according to the angle requirements of the diffuse reflection light. A layer of silicone grease is coated on the lower surface of the substrate 6, and an indium foil is attached to the lower surface of the silicone grease. The thickness of the silicone grease is 5-10μm, and the thickness of the indium foil is 1-2mm. The extinction array component 1 is processed by chemical gold plating process, and a layer of gold film is formed on the surface, with a solar absorption ratio of 0.3±0.05 and an infrared emissivity of ≤0.1.

[0032] The deep cryogenic space infrared camera hood includes a light extinction array component 1, a hood body 2, a cold finger interface 4, a cold finger clamp 3 and a ball joint component 5, and the light extinction array component 1, the cold finger interface 4, the cold finger clamp 3 and the ball joint component 5 are respectively connected to the hood body 2.

[0033] There are two cold finger interfaces 4, located on the left and right sides of the light shield body 2, and fastened by screws. There are six ball joint assemblies 5, one group on each side of the light shield body 2, three in each group, fastened by screws. The outer and inner wall areas of the light shield body 2 away from the light opening are provided with mounting holes, the outer mounting holes are used to fix the cold finger interfaces 4, the cold finger clamps 3 and the ball joint assemblies 5, and the inner wall mounting holes are used to fix the extinction array assembly 1. The extinction array assembly 1 includes four groups, which are located on the inner side of the light shield body 2 and arranged circumferentially along the inner wall of the light shield body 2. The cold finger interface is used to connect the cold finger; the ball joint assembly is used to be fixedly connected to the light shield support frame; the cold finger clamp is used to fix the cold finger belt. The light shield body 2 is processed by mechanical processing and then treated with chemical gold plating. The diameter of each mounting hole is 3mm. The effective light aperture of the light shield is ≥200mm×200mm.

[0034] Aiming at the problem of insufficient infrared stray light suppression capability of space optical cameras, the present invention designs a 120K deep cryogenic space infrared camera light shield, which is composed of a light extinction array component 1, a light shield body 2, a cold finger interface 4, a cold finger clamp 3, a ball joint component 5, and other metal connecting parts, and can achieve the stray light suppression capability of three spectral bands: short-wave infrared, medium-wave infrared and long-wave infrared; it adopts the light extinction array component 1 as the stray light suppression core component, has a simple overall structure and high space utilization; at a rated working temperature of 120K Under the condition of 100°C, the extinction array can reflect stray light to the outside of the sunshade, so as to achieve the requirement of stray light suppression without increasing the radiation of the sunshade body; under the condition of rated working temperature, the indium foil, thermal conductive silicone grease and other materials inside it can promote heat transfer; in addition, to prevent the support structure from transferring heat to the sunshade body, the ball hinge assembly 5 can effectively reduce heat transfer through the small contact area between the ball and the hinge, and at the same time realize effective support for the sunshade. A limit structure is designed for the sunshade to ensure that the sunshade works within the normal range. The cold finger interface 4 and the cold finger clamp 3 can effectively ensure the transmission and fixation of the cold source.

[0035] like Figure 4 As shown, the ball joint assembly consists of a thermal insulation pad, a ball head column, a hinge plate, a clamp, and a screw. The ball joint assembly is used to be fixedly connected to the light shield support frame; one end of the ball head column is fixed to the light shield body by a screw, and a thermal insulation pad is arranged between the ball head column and the light shield body, and the other end of the ball head column is connected to the clamp through the hinge plate, and the clamp is also clamped on the light shield support frame.

[0036] The principle of the invention is as follows: the deep cryogenic space infrared camera hood is brought into contact with the lens cold finger through two cold finger interfaces; the hood is ensured to have an operating temperature of 120K, and is connected and fixed to the inner surface of the hood through four extinction array components; the infrared radiation in the extinction array is initially absorbed by indium foil; further absorbed by thermal conductive silicone grease to achieve the function of heat absorption, and together with the hood body, the infrared radiation absorption in four directions is achieved, and precise heat insulation is performed through a ball joint structure and fixed points.

[0037] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A 120K deep cryogenic space infrared camera extinction array assembly, characterized by: It includes a matte array plate and a heat-conducting layer, wherein the matte array plate includes a matte sheet and a substrate, and the heat-conducting layer includes indium foil and silicone grease; A plurality of matting sheets are arranged in parallel on the upper surface of a substrate at equal intervals, a layer of silicone grease is coated on the lower surface of the substrate, and an indium foil is attached to the lower surface of the silicone grease; After the extinction array component is formed, the whole is treated with a chemical gold plating process, the solar absorption ratio is 0.3±0.05, and the infrared emissivity is ≤0.

1.

2. The extinction array assembly based on a 120K deep cryogenic space infrared camera according to claim 1, characterized in that: Determine the height and spacing of the matte sheets according to the angle requirements of the secondary diffuse reflection light.

3. A 120K deep cryogenic space infrared camera hood, characterized by: It comprises a light shield body, a cold finger interface, a cold finger clamp, a ball joint assembly and the light extinction array assembly according to claim 1; Taking the symmetry axis of the light shield as a reference, cold finger interfaces are symmetrically installed on the left and right sides of the light shield body, and the cold finger interfaces are used to connect cold fingers; Ball hinge assemblies are symmetrically installed on the left and right sides of the sunshade body, and the ball hinge assemblies are used to be fixedly connected to the sunshade support frame; Cold finger clamps are symmetrically installed on the left and right sides of the hood body to fix the cold finger belt; The inner wall of the light shield body is provided with extinction array components around the circumference, and the indium foil of the extinction array components is in close contact with the inner wall surface of the light shield body; The surface of the light shield body is processed by chemical gold plating after being machined and formed.

4. The 120K deep cryogenic space infrared camera light shield according to claim 3, characterized in that: There are six ball joint assemblies in total, and three are installed on each of the left and right sides of the light shield body.

5. The 120K deep cryogenic space infrared camera light shield according to claim 3, characterized in that: The outer surface of the light shield body is provided with a cold finger interface, a cold finger clamp, and a ball joint assembly installation hole, and the inner wall of the light shield body is processed with a light extinction array assembly installation hole in an area away from the light opening.

6. The 120K deep cryogenic space infrared camera light shield according to claim 5, characterized in that: The diameters of the cold finger interface mounting holes, the cold finger clamp mounting holes, the ball joint assembly mounting holes, and the extinction array assembly mounting holes are 3 to 5 mm.

7. The 120K deep cryogenic space infrared camera light shield according to claim 3, characterized in that: The main material of the lens hood is aluminum alloy.

8. The 120K deep cryogenic space infrared camera light shield according to claim 3, characterized in that: The effective aperture of the sunshade is ≥200mm×200mm.

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