Integrated supporting system for coaxial two-reflection low-temperature infrared optical system

Abstract

The invention relates to the technical field of low-temperature infrared cameras, in particular to an integrated supporting system for a coaxial two-reflector low-temperature infrared optical system, which comprises a primary mirror unit, a secondary mirror unit and a connecting unit. And the connecting unit is used for connecting the primary mirror unit and the secondary mirror unit and limiting the relative position between the primary mirror unit and the secondary mirror unit. The back of the primary mirror unit is not shielded, refrigeration equipment can be conveniently installed on the back of the primary mirror, the temperature uniformity of the primary mirror is improved, and the surface shape precision of the primary mirror is guaranteed. The primary mirror adopts a flexible peripheral supporting structure, so that the size in the optical axis direction can be remarkably shortened, the compactness and the structural temperature adaptability of the telescope structure are improved, and the influence of assembly stress on the surface type is reduced. In the primary mirror unit, the annular primary mirror supporting module is connected with the telescope barrel and serves as a primary mirror support, and the structure utilization rate is improved. A flexible structure is also adopted at a telescope mounting interface, so that external thermal stress transfer is remarkably inhibited, and the imaging quality and long-term stability are effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature infrared cameras, in particular to an integrated support system for a coaxial two-mirror low-temperature infrared optical system. Background Art

[0002] With the widespread application of high-sensitivity infrared detection technology in deep space exploration, meteorological monitoring, and commercial remote sensing, infrared imaging systems are developing towards high resolution, low noise, lightweight, and compact structures. To improve the detection sensitivity of infrared systems, reducing the operating temperature of optical lenses has become a key approach. However, in low-temperature environments, thermal stress and assembly stress in traditional infrared optical systems often lead to problems such as positional offset of the primary and secondary mirrors and structural deformation, which in turn degrades imaging performance. Coaxial twin-mirror telescopes are widely used in low-temperature infrared systems due to their symmetrical structure, coaxial optical axes, high imaging quality, and compact system.

[0003] At present, the Chinese invention patent application disclosure (publication number: CN116699927B) discloses a remote sensing camera with an integrated silicon carbide primary mirror and substrate. In order to solve the installation and alignment accuracy of the primary mirror and avoid the internal stress introduced by the integration of the primary mirror, the primary mirror and the back plate adopt an integrated silicon carbide molding scheme. Due to the existence of the back plate, the overall structure of the system is redundant and it is difficult to compress the optical path length, which limits the compactness and lightweight design space of the telescope structure. In addition, the space behind the primary mirror is closed, which is not conducive to the installation of active refrigeration devices such as cold screens or cold chains on the back of the primary mirror. It is difficult to ensure the uniformity of the mirror temperature distribution and the thermal stability of the system under low temperature conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated support system for a coaxial two-mirror low-temperature infrared optical system, which mainly solves the technical problems of the above-mentioned existing technologies, such as structural redundancy, high quality, difficulty in cooling the back of the primary mirror, poor temperature adaptability, large assembly stress affecting the mirror surface shape, and structure unsuitable for batch processing of low-temperature infrared telescopes.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide an integrated support system for a coaxial two-mirror low-temperature infrared optical system, characterized in that it includes a primary mirror unit, a secondary mirror unit and a connecting unit; the connecting unit is located between the primary mirror unit and the secondary mirror unit, connects the primary mirror unit and the secondary mirror unit, and limits the relative position between the primary mirror unit and the secondary mirror unit; the back of the primary mirror unit is unobstructed.

[0006] Furthermore, the main mirror unit includes a main mirror and a main mirror support module; the main mirror support module is arranged around the main mirror, forms a flexible connection with the main mirror in a peripheral support manner and fixes the main mirror, thereby exposing the back structure of the main mirror; the main mirror support module is fixed to the connecting unit.

[0007] Furthermore, a plurality of radial circular holes are provided on the main mirror; metal bushings are glued in the radial circular holes; the flexible jack module is provided at the position of the main mirror support module corresponding to the radial circular holes; the flexible jack module forms elastic deformation ability in the required direction by opening narrow slots on the support structure, thereby forming a flexible connection while ensuring the support strength; the metal bushing cooperates with the flexible jack module to flexibly fix the main mirror on the main mirror support module; the plurality of radial circular holes and the plurality of flexible jack modules are evenly distributed along the circumference of the main mirror or the main mirror support module.

[0008] Furthermore, a telescope barrel mounting module is provided on the primary mirror supporting module for fixing the primary mirror unit in the telescope barrel; the telescope barrel mounting module connects and fixes the primary mirror unit to the telescope barrel using a flexible connection.

[0009] Furthermore, the telescope tube mounting module includes multiple flexible mounting interfaces; the flexible mounting interfaces form elastic deformation capabilities in the required direction by setting flexible grooves or thin-walled areas on the supporting structure, thereby forming a flexible connection while ensuring support strength; the multiple flexible mounting interfaces are evenly distributed along the circumference of the primary mirror support module.

[0010] Furthermore, the secondary mirror unit includes a secondary mirror, a secondary mirror chamber and a secondary mirror support module; the secondary mirror chamber fixes the secondary mirror in a peripheral support manner; the secondary mirror chamber is further fixed on the secondary mirror support module; and the secondary mirror support module is fixed on the connecting unit.

[0011] Furthermore, a plurality of first fixing plates are arranged around the secondary mirror chamber; a second fixing plate matching the first fixing block is arranged at a corresponding position on the secondary mirror support module; a transfer block is used to connect the corresponding first fixing block and the second fixing plate, thereby completing the connection and fixation between the secondary mirror chamber and the secondary mirror support module; a plurality of first fixing blocks and a plurality of second fixing plates are evenly distributed along the circumference of the secondary mirror support module.

[0012] Furthermore, the connecting unit is a load-bearing cylindrical structure or a truss structure; one end of the load-bearing cylindrical structure or the truss structure is fixed to the primary mirror unit, and the other end is fixed to the secondary mirror unit.

[0013] Furthermore, the truss structure includes a plurality of hollow rods, both ends of which are respectively connected to the primary mirror unit and the secondary mirror unit; the plurality of hollow rods are evenly distributed along the circumference of the primary mirror unit and the secondary mirror unit.

[0014] Furthermore, the load-bearing cylindrical structure is in the shape of a thin-walled frustum; the diameter of the upper plane of the frustum is larger than that of the secondary mirror unit, and is fixedly connected to the secondary mirror unit through multiple support rods; the support rods are evenly distributed along the circumferential direction of the upper plane of the frustum; the diameter of the lower plane of the frustum matches that of the primary mirror unit, and is directly fixed to the primary mirror unit.

[0015] In view of the above technical features, the integrated support system for a coaxial dual-mirror low-temperature infrared optical system of the present invention has the following significant advantages over the prior art:

[0016] 1. This invention is used in an integrated support system for a coaxial dual-mirror low-temperature infrared optical system. The primary mirror utilizes a peripheral support structure, which significantly reduces its optical axis dimensions compared to a back support structure, improving the compactness of the telescope structure. Under gravity and temperature fluctuations, the primary mirror maintains surface error within a range of better than λ / 50 (RMS), significantly reducing deformation caused by assembly and thermal stresses and significantly improving surface stability. Furthermore, the peripheral support structure is flexible, improving the structural temperature adaptability and reducing the impact of assembly stress on the surface shape.

[0017] 2. This invention is used in an integrated support system for a coaxial dual-mirror cryogenic infrared optical system. The annular support at the primary mirror end serves as both an integral component of the telescope barrel structure and a support for the primary mirror, improving structural utilization and reducing telescope weight by approximately 25% compared to conventional designs. The annular structure above and below the telescope barrel also enhances its overall rigidity.

[0018] 3. This invention is used in an integrated support system for a coaxial dual-mirror low-temperature infrared optical system. The primary mirror's annular peripheral support structure fully exposes and frees up space behind the mirror, facilitating the installation of a cold shield or cold chain to achieve both radiative and conductive cooling of the mirror. This improves the mirror's temperature uniformity and ensures the mirror's surface accuracy. After integrating the cold shield into the mirror's back space, the mirror's temperature uniformity is improved to within ±0.5K, effectively reducing surface distortion caused by thermal gradients.

[0019] 4. This invention is used in an integrated support system for a coaxial dual-mirror low-temperature infrared optical system. The telescope mounting interface also utilizes a flexible structure, which helps reduce the impact of thermal stress generated by external structural deformation on the primary mirror. The flexible interface significantly suppresses the transmission of external thermal stress under temperature fluctuations, effectively ensuring the system's imaging quality and long-term stability in complex service environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment of the integrated support system for a coaxial dual-mirror low-temperature infrared optical system of the present invention;

[0021] Figure 2 This is a schematic diagram of the connection structure between the primary mirror and the primary mirror support module in the primary mirror unit in a preferred embodiment of the integrated support system for a coaxial dual-mirror low-temperature infrared optical system of the present invention;

[0022] Figure 3 This is a schematic structural diagram of a telescope tube mounting module in a primary mirror unit in a preferred embodiment of the integrated support system for a coaxial dual-mirror low-temperature infrared optical system according to the present invention;

[0023] Figure 4 yes Figure 3 A partial enlarged view of the flexible mounting interface;

[0024] Figure 5 This is a structural schematic diagram of a secondary mirror unit in a preferred embodiment of the integrated support system for a coaxial dual-mirror low-temperature infrared optical system of the present invention;

[0025] Figure 6 This is another preferred embodiment of the integrated support system for a coaxial dual-reflector low-temperature infrared optical system of the present invention, in which a connection diagram of the connection unit is realized by using a load-bearing cylindrical structure.

[0026] In the figure: 100-primary mirror unit, 200-secondary mirror unit, 300-connecting unit;

[0027] 101-primary mirror, 102-primary mirror support module, 103-metal bushing, 104-flexible jack module, 105-flexible mounting interface;

[0028] 201 - secondary mirror, 202 - secondary mirror chamber, 203 - secondary mirror support module, 204 - adapter block, 205 - first fixing plate, 206 - second fixing plate;

[0029] 301-Hollow rod, 302-Support rod. DETAILED DESCRIPTION

[0030] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0031] See also Figures 1 to 6The present invention discloses an integrated support system for a coaxial dual-mirror cryogenic infrared optical system. As shown in the figure, a preferred embodiment comprises a primary mirror unit 100, a secondary mirror unit 200, and a connecting unit 300. The connecting unit 300 is located between the primary and secondary mirror units 100 and 200, securing the two units together to form a single unit.

[0032] The main mirror unit 100 includes a main mirror 101 and a main mirror support module 102. The main mirror 101 is an optical device in the infrared optical system, and in this embodiment, it is a circular reflector. The main mirror support module 102 is annular, and its inner diameter is slightly larger than the diameter of the main mirror 101. The main mirror support module 102 is arranged around the main mirror 101, surrounding the main mirror 101 from the outside, so that the back of the main mirror 101 is unobstructed. There is a flexible connection between the main mirror 101 and the main mirror support module 102. The main mirror support module 102 fixes the main mirror 101 through the flexible connection in a peripheral support manner, so that the back structure of the main mirror 101 is fully exposed, which is convenient for installing cooling equipment.

[0033] Specifically, the primary mirror 101 is provided with multiple radial circular holes, preferably three to four, evenly distributed along the outer circumference of the primary mirror 101. Metal bushings 103 are cemented into these radial holes; the length of the bushings 103 is greater than the depth of the holes. This allows one end of the metal bushing 103 to protrude from the primary mirror 101, forming a protrusion. In this embodiment, a total of four metal bushings 103 are provided to connect the primary mirror 101 to the primary mirror support module 102.

[0034] Correspondingly, flexible jack modules 104 are provided on the main mirror support module 102 at positions corresponding to the radial circular holes on the main mirror 101, so that the flexible jack modules 104 are evenly distributed along the inner circumference of the main mirror support module 102. The metal bushing 103 extending from the main mirror 101 cooperates with the flexible jack module 104 and is inserted into the flexible jack module 104, thereby forming a flexible fixation between the main mirror 101 and the main mirror support module 102. The flexible jack module 104 is a hollow metal triangular structure with a plurality of U-shaped or C-shaped slits provided on the ribs on both sides. The slits are formed by wire cutting or micromachining. The cutting depth, width and distribution angle of the slits are designed and adjusted according to the required flexibility range. The slit structure enables the flexible jack module 104 to have a certain elastic deformation ability in the radial direction when subjected to force, thereby achieving the structural characteristics of rigid support and flexible buffering.

[0035] The primary mirror support module 102 is also provided with a telescope barrel mounting module, which secures the primary mirror unit 100, along with the secondary mirror unit 200 connected to it via the connection unit 300, within the telescope barrel. The telescope barrel mounting module comprises a plurality of flexible mounting interfaces 105, evenly distributed along the outer circumference of the primary mirror support module 102. These flexible mounting interfaces 105 form a flexible connection between the telescope barrel and the primary mirror unit 100. Specifically, to accommodate micro-deformation of the telescope barrel under low-temperature conditions, the flexible mounting interfaces 105 are provided with flexible grooves or thin-walled areas. These allow for limited elastic deformation in the radial or axial directions without compromising connection strength, thereby providing vibration reduction and stress relief. These flexible grooves or thin-walled areas are formed using a wire cutting process. In this embodiment, four flexible mounting interfaces 105 are provided, evenly distributed along the circumference of the primary mirror support module 102, ensuring uniform structural stress, symmetrical assembly, and a reasonable thermal field distribution.

[0036] The secondary mirror unit 200 includes a secondary mirror 201, a secondary mirror chamber 202, and a secondary mirror support module 203. In the secondary mirror unit 200, the secondary mirror 201 is an optical device in the infrared optical system. In this embodiment, it is a circular reflector with a diameter smaller than the primary mirror 101. On the outer edge of the secondary mirror 201 is an annular secondary mirror chamber 202, whose inner diameter is slightly larger than the diameter of the secondary mirror 201. The secondary mirror chamber 202 is fixed to the outside of the secondary mirror 201 in a peripheral support manner. The secondary mirror support module 203 also has an annular structure, and its outer diameter matches the outer diameter of the secondary mirror chamber 202. The secondary mirror chamber 202 and the secondary mirror support module 203 are installed against each other. Specifically, a plurality of first fixing plates 205 are evenly arranged on the outer circumference of the secondary mirror chamber 202. Correspondingly, a matching second fixing plate 206 is set at a corresponding position on the secondary mirror support module 203. That is, the second fixing plates 206 are evenly arranged along the outer circumference of the secondary mirror support module 203, and the first fixing plates 205 and the second fixing plates 206 are aligned. Bolts are used to secure the ends of the adapter block 204 to the first fixing block and the second fixing plates 206, respectively. Thus, the first fixing plates 205 and the second fixing plates 206 securely connect the secondary mirror chamber 202 and the secondary mirror support module 203. In this embodiment, four sets of first fixing plates 205 and second fixing plates 206 are provided, connected and secured using four adapter blocks 204.

[0037] The connecting unit 300 is located between the primary mirror unit 100 and the secondary mirror unit 200. It is responsible for connecting and fixing the primary mirror unit 100 and the secondary mirror unit 200, thereby limiting the relative position between the primary mirror unit 100 and the secondary mirror unit 200 and ensuring the stability of the optical structure. One end of the connecting unit 300 is fixed to the primary mirror support module 102, and the other end is fixed to the secondary mirror support module 203. Its structure is a load-bearing cylindrical structure or a truss structure. In this embodiment, a truss structure is adopted, consisting of four hollow rods 301. The two ends of the hollow rods 301 are respectively connected to the primary mirror support module 102 and the secondary mirror support module 203. These hollow rods 301 are evenly distributed along the circumference of the primary mirror support module 102 and the secondary mirror support module 203, thereby forming a stable support structure.

[0038] In other embodiments, a load-bearing cylindrical structure may also be employed. In this load-bearing cylindrical structure, a thin-walled truncated cone-shaped cylindrical structure connects the primary mirror support module 102 and the secondary mirror support module 203. The diameter of the upper surface of the truncated cone is larger than the outer diameter of the secondary mirror support module 203. It is connected and fixed to the secondary mirror support module 203 by four support rods 302 evenly distributed along the circumference and at 90-degree angles. The diameter of the lower surface of the truncated cone matches that of the primary mirror support module 102 and is directly fixed to the primary mirror support module 102.

[0039] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An integrated support system for a coaxial two-mirror low-temperature infrared optical system, characterized in that: The invention comprises a primary mirror unit, a secondary mirror unit and a connecting unit; the connecting unit is located between the primary mirror unit and the secondary mirror unit, connects the primary mirror unit and the secondary mirror unit, and limits the relative position between the primary mirror unit and the secondary mirror unit; the back of the primary mirror unit is unobstructed.

2. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 1, characterized in that: The main mirror unit includes a main mirror and a main mirror support module; the main mirror support module is arranged around the main mirror, forms a flexible connection with the main mirror in a peripheral support manner and fixes the main mirror, thereby exposing the back structure of the main mirror; the main mirror support module is fixed to the connecting unit.

3. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 2, characterized in that: A plurality of radial circular holes are provided on the main mirror; metal bushings are glued in the radial circular holes; the flexible jack module is provided at the position of the main mirror support module corresponding to the radial circular holes; the flexible jack module is elastically deformed in a required direction by opening narrow slots on the support structure, thereby forming a flexible connection while ensuring the support strength; the metal bushing cooperates with the flexible jack module to flexibly fix the main mirror on the main mirror support module; the plurality of radial circular holes and the plurality of flexible jack modules are evenly distributed along the circumference of the main mirror or the main mirror support module.

4. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 2, characterized in that: A telescope barrel mounting module is further provided on the primary mirror supporting module for fixing the primary mirror unit in the telescope barrel; the telescope barrel mounting module connects and fixes the primary mirror unit to the telescope barrel using a flexible connection.

5. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 4, characterized in that: The telescope tube mounting module includes multiple flexible mounting interfaces; the flexible mounting interfaces form elastic deformation capabilities in the required direction by setting flexible grooves or thin-walled areas on the support structure, thereby forming a flexible connection while ensuring support strength; the multiple flexible mounting interfaces are evenly distributed along the circumference of the primary mirror support module.

6. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 1, characterized in that: The secondary mirror unit includes a secondary mirror, a secondary mirror chamber and a secondary mirror support module; the secondary mirror chamber fixes the secondary mirror in a peripheral support manner; the secondary mirror chamber is further fixed on the secondary mirror support module; and the secondary mirror support module is fixed on the connecting unit.

7. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 6, characterized in that: A plurality of first fixing plates are arranged around the secondary mirror chamber; a second fixing plate matching the first fixing block is arranged at a corresponding position on the secondary mirror support module; a transfer block is used to connect the corresponding first fixing block and the second fixing plate, thereby completing the connection and fixation between the secondary mirror chamber and the secondary mirror support module; a plurality of first fixing blocks and a plurality of second fixing plates are evenly distributed along the circumference of the secondary mirror support module.

8. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 1, characterized in that: The connecting unit is a load-bearing cylindrical structure or a truss structure; one end of the load-bearing cylindrical structure or the truss structure is fixed to the primary mirror unit, and the other end is fixed to the secondary mirror unit.

9. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 8, characterized in that: The truss structure includes a plurality of hollow rods, both ends of which are connected to the primary mirror unit and the secondary mirror unit respectively; the plurality of hollow rods are evenly distributed along the circumference of the primary mirror unit and the secondary mirror unit.

10. The integrated support system for a coaxial two-mirror low-temperature infrared optical system according to claim 8, characterized in that: The load-bearing cylindrical structure is in the shape of a thin-walled truncated cone; the diameter of the upper plane of the truncated cone is larger than that of the secondary mirror unit, and is fixedly connected to the secondary mirror unit through multiple support rods; the support rods are evenly distributed along the circumferential direction of the upper plane of the truncated cone; the diameter of the lower plane of the truncated cone matches that of the primary mirror unit, and is directly fixed to the primary mirror unit.

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