A 120K deep cryogenic space infrared camera extinction array assembly and light shield

Abstract

The present invention relates to an extinction array assembly and light shield for a 120K deep-cryogenic space infrared camera. The extinction array assembly includes an extinction array plate and a thermal conductive layer. The extinction array plate includes an extinction sheet and a substrate. The thermal conductive layer includes indium foil and silicone grease. The light shield includes an extinction array assembly, a light shield body, a cold finger interface, a cold finger clamp, and a ball joint assembly. The deep-cryogenic space infrared camera light shield is brought into contact with the lens cold finger via two cold finger interfaces. The light shield maintains an operating temperature of 120K by connecting and fixing the extinction array assembly to the inner surface of the light shield at four locations. Infrared radiation from the extinction array is initially absorbed by the indium foil. Further absorption is achieved by thermal conductive silicone grease, achieving a heat absorption function. Together with the light shield body, the assembly absorbs infrared radiation in four directions. Precise thermal insulation is achieved via a ball joint structure and fixed points.

Description

Technical Field

[0001] The present 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 remote sensing satellite resolution continues to improve, the demand for higher-quality imaging is growing. The infrared radiation generated by components surrounding the onboard field of view (communication antennas, solar panels, thrust engines, and other components) is increasingly impacting image quality. Stray light suppression has become essential to ensure image quality. Light shields and extinction arrays are key components of modern optical systems. Their temperature range and ability to suppress stray light determine whether the overall optical system's performance meets design specifications.

[0003] To prevent excessive invalid pixels from being generated by stray light, the sunshade often requires the addition of extinction structures (such as extinction honeycombs or black paint). However, for closely spaced, highly diffusely reflective components, such as those onboard other payloads, excessive stray light can result, leading to reduced imaging quality in the optical system. To address the shortcomings of traditional extinction systems (combinations of extinction honeycombs and black paint), which have limited ability to suppress stray light from onboard components, it is necessary to develop new, high-performance extinction devices that can comprehensively control stray light and maximize the field of view under varying incident angles. Traditional extinction approaches can be categorized as extinction honeycombs and black paint. Both absorb stray light and convert it into infrared radiation. These extinction methods are spectral-dependent, and the resulting radiation may be excessive in the infrared detection band. When the sunshade's inherent radiation far exceeds the cooling capacity, the image quality of a deep-cryogenic space infrared camera deteriorates as the sunshade's temperature 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 light shield extinction technology, especially the infrared stray light suppression capability of on-board components, and propose an extinction array assembly and light shield 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. 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 plate and a heat-conducting layer, wherein the extinction array plate 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 entire component is treated with a chemical gold plating process, with a solar absorption ratio of 0.3±0.05 and an infrared emissivity of ≤0.1.

[0009] Preferably, the height and spacing of the matte sheets are determined according to the angle requirements 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 belts;

[0014] The inner wall of the light shield body is provided with extinction array components all around the body, 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 light shield 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 an 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) To improve the insufficient ability of the traditional extinction system (combination of extinction honeycomb and extinction black paint) to suppress stray light from onboard components, the present invention adopts an extinction array assembly, which has a simple structure and high space utilization. Combined with the gold plating process, the emissivity is improved. The light shield is provided with a cold finger interface, a ball joint assembly, and a cold finger clamp, thereby enhancing the high thermal conductivity, strong mechanical properties, and high machinability 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 low temperature space infrared camera hood at a rated temperature of 120K can achieve the stray light suppression capability 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 This is a schematic diagram of the assembly of the 120K deep cryogenic space infrared camera light shield of the present invention;

[0025] Figure 2 Schematic diagram of the internal structure of the extinction array assembly of the present invention;

[0026] Figure 3 This is a schematic structural diagram 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- matting array assembly, 2- light shield body, 3- cold finger clamp, 4- cold finger interface, 5- ball joint assembly, 6- base plate, 7- matting sheet. DETAILED DESCRIPTION

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

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

[0031] The matte array panel comprises matte sheets 7 and a substrate 6. The matte sheets 7 are arranged parallel to the upper surface of the substrate 6 at a height and spacing determined according to the angle of the secondary diffusely reflected light. The number of matte sheets 7 can be adjusted based on the required diffusely reflected light angle. The lower surface of the substrate 6 is coated with a layer of silicone grease, and the lower surface of the silicone grease is covered with indium foil. The silicone grease is 5-10 μm thick, and the indium foil is 1-2 mm thick. The matte array assembly 1 is treated with a chemical gold plating process to form a gold film on the surface. The solar absorption ratio is 0.3±0.05, and the infrared emissivity is ≤0.1.

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

[0033] There are two cold finger interfaces 4, located on the left and right sides of the light shield body 2, secured by screws. There are six ball hinge assemblies 5, one set of three on each side of the light shield body 2, secured by screws. Mounting holes are provided on the exterior and interior walls of the light shield body 2, away from the light opening. The exterior mounting holes are used to secure the cold finger interfaces 4, cold finger clamps 3, and ball hinge assemblies 5, while the interior mounting holes are used to secure the extinction array assembly 1. The extinction array assembly 1 comprises four groups, located on the interior side of the light shield body 2 and arranged circumferentially along its inner wall. The cold finger interfaces are used to connect the cold fingers; the ball hinge assemblies are used to securely connect to the light shield support frame; and the cold finger clamps are used to secure the cold finger belts. The light shield body 2 is machined and then chemically gold-plated. The diameter of each mounting hole is 3 mm. The effective light aperture of the light shield is ≥ 200 mm × 200 mm.

[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 an 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. It can achieve the stray light suppression capability of the three spectral bands of short-wave infrared, medium-wave infrared and long-wave infrared; it uses the extinction array component 1 as the core component for eliminating stray light, has a simple overall structure and high space utilization; at a rated operating temperature of 120K Under normal operating conditions, the extinction array can reflect stray light outside the sunshade, thereby achieving the requirement of stray light suppression without increasing the radiation of the sunshade itself. Under rated operating temperature conditions, the indium foil, thermal grease, and other materials inside the sunshade promote heat transfer. In addition, to prevent the support structure from transferring heat to the sunshade body, the ball hinge assembly 5 effectively reduces heat transfer through the small contact area between the ball and the hinge, while also effectively supporting the sunshade. A limit structure is designed for the sunshade to ensure that the sunshade operates within the normal range. The cold finger interface 4 and cold finger clamp 3 effectively ensure the transmission and fixation of the cold source.

[0035] like Figure 4 As shown, the ball hinge assembly consists of an insulation pad, a ball stud, a hinge plate, a clamp, and a screw. The ball hinge assembly is used to be fixedly connected to the sun hood support frame; one end of the ball stud is fixed to the sun hood body by a screw, and an insulation pad is provided between the ball stud and the sun hood body. The other end of the ball stud is connected to the clamp through the hinge plate, and the clamp is also clamped on the sun hood support frame.

[0036] The principle of the invention is as follows: the deep-cryogenic space infrared camera hood is connected to the lens cold finger through two cold finger interfaces; the operating temperature of the hood is guaranteed to be 120K, and the extinction array components are connected and fixed to the inner surface of the hood through four locations; the infrared radiation in the extinction array is initially absorbed by indium foil; further absorption is achieved through thermal conductive silicone grease to achieve the heat absorption function, and together with the hood body, it provides infrared radiation absorption in four directions, and precise heat insulation is achieved through the ball joint structure and the 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 entire component is treated with a chemical gold plating process, with a solar absorption ratio of 0.3±0.05 and an infrared emissivity of ≤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 belts; The inner wall of the light shield body is provided with extinction array components all around the body, 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 lens hood according to claim 3, characterized in that: There are six ball joint assemblies in total, with three being installed on each of the left and right sides of the light shield body.

5. The 120K deep cryogenic space infrared camera lens hood 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 hinge assembly mounting hole, and the inner wall of the light shield body is processed with an extinction array assembly mounting hole in an area away from the light opening.

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

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

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