Method for assembling and adjusting coaxial three-mirror optical system

Abstract

The invention relates to the field of optical instruments, and discloses a method for adjusting a coaxial three-mirror optical system, which comprises the following steps of: performing comprehensive simulation analysis on a primary mirror system and a secondary mirror system by adopting optical design software, outputting simulation data, and calculating required adjusting parameters and accurately adjusting a secondary mirror by comparing the difference between the simulation data and actual test data. After the primary and secondary mirror system is installed and adjusted, the third mirror and the folding mirror are combined through a mechanical installation piece and installed behind the light path of the primary and secondary mirror system, and it is ensured that the light paths of the primary and secondary mirror system, the third mirror and the folding mirror can be correctly connected. And finally, testing the coaxial three-mirror optical system, and if the test result is qualified, completing the installation and adjustment work of the coaxial three-mirror optical system. According to the installation and adjustment method of the coaxial three-mirror optical system, installation and adjustment of the secondary mirror are optimized, and the problem that the installation and adjustment difficulty is large due to the fact that the secondary mirror has a certain eccentric angle is effectively solved.

Description

Technical Field

[0001] The invention relates to the field of optical instruments, and in particular to an assembly and adjustment method for a coaxial three-mirror optical system. Background Art

[0002] The coaxial three-mirror optical system is a special optical system with the characteristics of compact structure, high light transmission efficiency and excellent imaging quality. The system is designed based on the principle of light reflection. The light passes through the primary mirror, secondary mirror and tertiary mirror in sequence, and finally guides the light to the same axis to achieve image formation and transmission.

[0003] In a traditional coaxial three-mirror optical system, the optical axes of the primary mirror, secondary mirror, and tertiary mirror are usually kept precisely coaxial. However, in order to enhance the aberration correction capability of the system's rear-end optical path, the secondary mirror in some coaxial three-mirror optical systems is designed to have a slight eccentricity, which causes the optical axes of the primary and secondary mirrors to no longer completely coincide, and because the tolerance range of the secondary mirror is extremely small, even a slight deviation will significantly affect the system performance. Therefore, the precise position and angle adjustment of the secondary mirror is crucial to ensure high-quality imaging; unfortunately, existing adjustment technologies cannot solve the problem of difficulty in adjustment caused by a certain eccentric angle of the secondary mirror. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a method for assembling and adjusting a coaxial three-mirror optical system, which uses optical design software to perform a comprehensive simulation analysis of the primary and secondary mirror systems, pre-evaluates the imaging quality defects that may be caused by the secondary mirror eccentricity, constructs the primary and secondary mirror systems based on the optical design results, and calculates the required adjustment parameters by comparing the differences between the simulation data and the actual test data to accurately adjust the secondary mirror; effectively solves the problem of image quality degradation caused by the secondary mirror eccentricity, and significantly reduces the difficulty of assembling the coaxial three-mirror optical system.

[0005] The present invention provides a method for assembling and adjusting a coaxial three-mirror optical system, wherein the coaxial three-mirror optical system comprises: a primary mirror assembly, a primary-secondary mirror connecting bracket, a secondary mirror, three mirrors and a folding mirror assembly; the method for assembling and adjusting the coaxial three-mirror optical system comprises:

[0006] Fix the primary mirror assembly on the fixture, and connect the primary mirror assembly to one end of the primary-secondary mirror connecting bracket;

[0007] Use optical design software to simulate and analyze the primary and secondary mirror systems to obtain the primary image plane light path simulation data;

[0008] The secondary mirror is mounted and adjusted at the other end of the primary-secondary mirror connection bracket, and an optical test is performed on the secondary mirror to obtain primary image plane optical path data;

[0009] According to the primary image plane light path simulation data and the primary image plane light path data, the adjustment data is obtained, and the secondary mirror is installed and adjusted according to the adjustment data to complete the construction of the primary and secondary mirror system;

[0010] Install the folding mirror assembly on the rear side of the main mirror assembly;

[0011] Install the three mirrors at the interface of the folding mirror assembly, connect the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror, and complete the construction of the coaxial three-mirror optical system;

[0012] The coaxial three-mirror optical system is tested to obtain a test result. If the test result meets the preset qualified conditions, the installation and adjustment of the coaxial three-mirror optical system is completed.

[0013] Optionally, in a first implementation of the present invention, the main mirror assembly includes a main mirror and a main mirror back plate; fixing the main mirror assembly on a tooling and connecting the main mirror assembly to one end of a primary-secondary mirror connecting bracket includes: installing the main mirror back plate on the tooling; connecting the main mirror to the main mirror back plate so that the optical axis of the main mirror coincides with the mechanical axis of the back plate to complete the assembly of the main mirror assembly; connecting the main mirror assembly to one end of the primary-secondary mirror connecting bracket.

[0014] Optionally, in a second implementation of the present invention, the use of optical design software to simulate and analyze the primary and secondary mirror systems to obtain primary image plane light path simulation data includes: obtaining primary mirror parameters and secondary mirror parameters; and using optical design software to optically simulate the primary and secondary mirror systems according to the primary mirror parameters and secondary mirror parameters to obtain primary image plane light path simulation data.

[0015] Optionally, in a third implementation of the present invention, the secondary mirror is installed at the other end of the primary-secondary mirror connecting bracket, and the secondary mirror is optically tested to obtain primary image plane light path data, including: installing the secondary mirror at the other end of the primary-secondary mirror connecting bracket, adjusting the primary mirror assembly and the secondary mirror to form a primary-secondary mirror system; and optically testing the primary-secondary mirror system to obtain primary image plane light path data.

[0016] Optionally, in a fourth implementation of the present invention, the adjustment data is obtained according to the primary image plane optical path simulation data and the primary image plane optical path data, and the secondary mirror is adjusted according to the adjustment data to complete the construction of the primary-secondary mirror system, which includes: comparing and analyzing the primary image plane optical path simulation data and the primary image plane optical path data to obtain difference data; analyzing the difference data using optical software to obtain adjustment data; and adjusting the secondary mirror according to the adjustment data to complete the optical path construction of the primary-secondary mirror system.

[0017] Optionally, in a fifth implementation of the present invention, the folding mirror assembly includes an L mirror, a reflective mirror and a mechanical mounting part; installing the folding mirror assembly on the main mirror back panel assembly includes: installing the L mirror on the L mirror position of the mechanical mounting part, installing the reflective mirror on the reflective mirror position of the mechanical mounting part, to complete the combination of the folding mirror assembly; installing the folding mirror assembly on the rear side of the main mirror assembly.

[0018] Optionally, in a sixth implementation of the present invention, the three mirrors are installed at the interface of the folding mirror assembly, and the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror are connected to complete the construction of the coaxial three-mirror optical system, including: installing the three mirrors at the interface of the folding mirror assembly; using optical design software to perform optical simulation on the three mirrors to obtain secondary image plane optical path simulation data; performing optical testing on the three mirrors to obtain secondary image plane optical path data; comparing the secondary image plane optical path simulation data with the secondary image plane optical path data to obtain three-mirror difference data; using optical software to analyze the three-mirror difference data to obtain three-mirror adjustment data; using the three-mirror adjustment data to adjust the three mirrors, and connecting the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror to complete the construction of the coaxial three-mirror optical system.

[0019] Optionally, in a seventh implementation of the present invention, the coaxial three-mirror optical system further includes a reference cubic prism and a prism seat. The three mirrors are installed at the interface of the folding mirror assembly, and the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror are connected. After completing the construction of the coaxial three-mirror optical system, the method includes: assembling the reference cubic prism on the side of the primary mirror assembly through the prism seat; repairing the prism seat, adjusting the position and posture of the prism seat, so that the three mutually perpendicular planes in the reference cubic prism are respectively parallel to the optical axis, horizontal axis and vertical axis of the primary mirror assembly; and using the reference cubic prism to mark the optical axis of the coaxial three-mirror optical system to obtain a marked coaxial three-mirror optical system.

[0020] Optionally, in an eighth implementation of the present invention, the coaxial three-mirror optical system further includes a focal plane assembly; after the optical axis of the coaxial three-mirror optical system is marked using a reference cubic prism to obtain the marked coaxial three-mirror optical system, the method further includes: installing the focal plane assembly at the focus of the optical path at the rear end of the folding mirror assembly; and performing imaging adjustment on the coaxial three-mirror optical system using the focal plane assembly to obtain the coaxial three-mirror optical system after imaging adjustment.

[0021] Optionally, in a ninth implementation of the present invention, the coaxial three-mirror optical system is tested to obtain a test result, and if the test result meets a preset qualification condition, the installation and adjustment of the coaxial three-mirror optical system is completed, including: testing the imaging quality of the coaxial three-mirror optical system to obtain a test result; if the test result meets a preset qualification condition, the installation and adjustment of the coaxial three-mirror optical system is completed.

[0022] In the technical solution of the present invention, optical design software is used to perform comprehensive simulation analysis on the primary and secondary mirror systems and output simulation data. By comparing the difference between the simulation data and the actual test data, the required adjustment parameters are calculated and the secondary mirror is accurately adjusted. After the primary and secondary mirror systems are installed, the three mirrors are combined with the folding mirror through mechanical mounting parts and installed after the optical path of the primary and secondary mirror systems to ensure that the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror can be correctly connected; finally, the coaxial three-mirror optical system is tested, and if the test result is qualified, the installation work of the coaxial three-mirror optical system is completed. The installation method of the coaxial three-mirror optical system provided by the present invention optimizes the installation of the secondary mirror and effectively solves the problem of difficulty in installation due to the secondary mirror having a certain eccentric angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 1 ;

[0025] Figure 2 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 2 ;

[0026] Figure 3 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 3 ;

[0027] Figure 4 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 4 ;

[0028] Figure 5 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 5 ;

[0029] Figure 6 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 6 ;

[0030] Figure 7 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 7 ;

[0031] Figure 8 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 8 ;

[0032] Fig. 9 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 9 ;

[0033] Fig.10 Process of the method for assembling and adjusting the coaxial three-mirror optical system provided by the embodiment of the present invention Figure 10 ;

[0034] Fig.11 A schematic diagram of the optical path of a coaxial three-mirror optical system provided in an embodiment of the present invention.

[0035] In the attached drawings: 1-primary mirror; 2-secondary mirror; 3-tertiary mirror; 4-first sub-reflecting mirror; 5-second sub-reflecting mirror; 6-reflecting mirror. DETAILED DESCRIPTION

[0036] The present invention provides a method for assembling and adjusting a coaxial three-mirror optical system. In the technical solution of the present invention, optical design software is used to perform comprehensive simulation analysis on the primary and secondary mirror systems and output simulation data. By comparing the difference between the simulation data and the actual test data, the required adjustment parameters are calculated and the secondary mirror is accurately adjusted. After the primary and secondary mirror systems are assembled and adjusted, the three mirrors are combined with the folding mirror through mechanical mounting parts and installed after the optical path of the primary and secondary mirror systems to ensure that the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror can be correctly connected; finally, the coaxial three-mirror optical system is tested. If the test result is qualified, the assembly and adjustment of the coaxial three-mirror optical system is completed. The method for assembling and adjusting a coaxial three-mirror optical system provided by the present invention optimizes the assembly and adjustment of the secondary mirror and effectively solves the problem of difficulty in assembly and adjustment caused by a certain eccentric angle of the secondary mirror.

[0037] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] For ease of understanding, the specific process of the embodiment of the present invention is described below. Figure 1 An embodiment of the method for assembling and adjusting the coaxial three-mirror optical system in the embodiment of the present invention includes:

[0039] The coaxial three-mirror optical system comprises: a primary mirror assembly, a primary-secondary mirror connecting bracket, a secondary mirror, a three-mirror and a folding mirror assembly;

[0040] In one embodiment, the primary mirror assembly is the front end of the coaxial three-mirror optical system, responsible for collecting light from distant objects and initially focusing it; the primary and secondary mirror connection bracket is used to accurately adjust and fix the position and angle of the secondary mirror to ensure that the secondary mirror can accurately receive the light reflected by the primary mirror and reflect it again; the secondary mirror is located near the focus of the primary mirror, and reflects the light reflected by the primary mirror again to form a primary image plane; the three mirrors are used to reduce the residual aberration introduced by the first two levels of reflection and guide the light to the final focal plane; in this embodiment, in order to reduce the overall size of the system and adjust the light path, a folding mirror assembly is introduced, and the folding mirror assembly is used to change the propagation direction of the light without significantly affecting the focusing characteristics of the light beam; in this embodiment, a mechanical mounting part is set to integrate the folding mirror assembly and the three mirrors into a mechanical structure; in this embodiment, the external light will first irradiate the primary mirror, and then be reflected by the primary mirror to the secondary mirror; the light emitted by the secondary mirror first enters the folding mirror assembly, and then is reflected by the folding mirror assembly to the three mirrors, and then reflected from the three mirrors back to the folding mirror assembly; finally, the light is emitted after multiple reflections in the folding mirror assembly.

[0041] The method for assembling and adjusting the coaxial three-mirror optical system comprises:

[0042] 101. Fix the primary mirror assembly on the fixture, and connect the primary mirror assembly to one end of the primary-secondary mirror connecting bracket;

[0043] In this embodiment, the installation of the primary mirror assembly is the starting point for the adjustment of the entire coaxial three-mirror optical system. First, the primary mirror assembly is firmly fixed on a special tooling; the tooling needs to be designed to be stable enough to ensure that the position of the primary mirror assembly does not change during the subsequent adjustment process; then, one end of the primary-secondary mirror connecting bracket is connected to the primary mirror assembly to prepare for the subsequent installation of the secondary mirror.

[0044] 102. Use optical design software to simulate and analyze the primary and secondary mirror systems to obtain the primary image plane light path simulation data;

[0045] In this embodiment, the advanced optical design software CODEV is used to perform a comprehensive simulation analysis of the primary and secondary mirror systems. By inputting the geometric parameters of the primary and secondary mirrors (such as curvature radius, thickness, material, etc.) and the overall layout of the system, the software can simulate the primary image plane light path simulation data of the primary and secondary mirror systems. The Zenike coefficient of the image plane can be analyzed based on the primary image plane light path data, and the Zenike coefficient is used for the subsequent adjustment of the secondary mirror.

[0046] 103. Install and adjust the secondary mirror at the other end of the primary-secondary mirror connection bracket, and perform an optical test on the secondary mirror to obtain primary image plane optical path data;

[0047] In this embodiment, the secondary mirror is first accurately adjusted at the other end of the primary-secondary mirror connecting bracket. After the adjustment is completed, an optical testing device (such as an interferometer) is used to perform an optical test on the secondary mirror, collect the first image plane interference pattern, and obtain the actual primary image plane optical path data. The actual Zenike coefficient can be analyzed through the primary image plane optical path data.

[0048] 104. According to the primary image plane light path simulation data and the primary image plane light path data, adjustment data is obtained, and the secondary mirror is installed and adjusted according to the adjustment data to complete the construction of the primary and secondary mirror system;

[0049] In this embodiment, by comparing the simulation data with the actual data, the adjustment amount of the secondary mirror can be calculated. These adjustment data usually include the translation and rotation direction and movement amount of the secondary mirror; according to these adjustment data, the secondary mirror is finely adjusted again, and the secondary mirror adjustment pad is ground to adjust the position of the secondary mirror until the actual test data is highly consistent with the simulation data, and the adjustment of the secondary mirror is completed, thereby completing the construction of the primary and secondary mirror system. This step is a key step to ensure the imaging quality of the system.

[0050] 105. Install the folding mirror assembly on the rear side of the main mirror assembly;

[0051] In this embodiment, after the adjustment of the primary and secondary mirror systems is completed, the folding mirror assembly is installed on the rear side of the primary mirror assembly; in this embodiment, the folding mirror assembly includes a reflecting mirror and two sub-reflecting mirrors, wherein the two sub-reflecting mirrors are combined into an L mirror, and both the L mirror and the reflecting mirror are fixed in a mechanical mounting part and are placed on the rear side of the primary mirror assembly to receive the light emitted by the secondary mirror; the installation of the folding mirror assembly needs to ensure that the propagation path of the light is consistent with expectations and does not introduce additional aberrations.

[0052] 106. Install the three mirrors at the interface of the folding mirror assembly, connect the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror, and complete the construction of the coaxial three-mirror optical system;

[0053] In this embodiment, the three mirrors are installed at the interface of the folding mirror assembly, and the light emitted by the secondary mirror first enters the folding mirror assembly, and then is reflected by the folding mirror assembly to the three mirrors, and then reflected from the three mirrors back to the folding mirror assembly; finally, the light is emitted after multiple reflections in the folding mirror assembly; the function of the three mirrors is to further correct the residual aberration introduced by the first two levels of reflection; by precisely adjusting the position and angle of the three mirrors, it can be ensured that the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror are correctly connected, thereby completing the overall construction of the coaxial three-mirror optical system.

[0054] 107. Testing the coaxial three-mirror optical system to obtain a test result. If the test result meets a preset qualified condition, the assembly and adjustment of the coaxial three-mirror optical system is completed;

[0055] In this embodiment, the last step of the installation of the coaxial three-mirror optical system is to test the entire coaxial three-mirror optical system; the test content includes but is not limited to imaging quality (such as resolution, contrast, etc.), aberration correction effect, focal length accuracy, etc.; the test can be carried out using dedicated optical testing equipment (such as interferometer, imager, etc.); if the test results meet the design requirements, it indicates that the installation of the coaxial three-mirror optical system has been completed.

[0056] In an embodiment of the present invention, the primary mirror assembly is first installed and fixed, and then the optical design software is used to perform a comprehensive simulation analysis on the primary and secondary mirror systems and output simulation data, and by comparing the difference between the simulation data and the actual test data, the required adjustment parameters are calculated and the secondary mirror is accurately adjusted. After the primary and secondary mirror systems are installed, the three mirrors are combined with the folding mirror through mechanical mounting parts and installed after the optical path of the primary and secondary mirror systems, ensuring that the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror can be correctly connected; finally, the coaxial three-mirror optical system is tested, and if the test result is qualified, the installation and adjustment of the coaxial three-mirror optical system is completed; the installation and adjustment method of the coaxial three-mirror optical system provided by the present invention optimizes the installation and adjustment of the secondary mirror, and effectively solves the problem of difficulty in installation and adjustment caused by a certain eccentric angle of the secondary mirror.

[0057] See also Figure 2 The second embodiment of the method for assembling and adjusting the coaxial three-mirror optical system in the embodiment of the present invention comprises:

[0058] The primary mirror assembly also includes a primary mirror and a primary mirror back plate;

[0059] In this embodiment, the primary mirror is located at the front end of the coaxial three-mirror optical system, and is used to reflect the external light for the first time. The back plate is the supporting structure of the primary mirror, and is used to connect the primary mirror with other components in the coaxial three-mirror optical system; the flexible joint is used to connect the primary mirror and the back plate, and is also responsible for fine-tuning the primary mirror; the flexible joint and the back plate are usually pre-combined into a primary mirror back plate.

[0060] 201. Install the primary mirror back plate on the tooling;

[0061] In this embodiment, the primary mirror back plate is firstly accurately placed on a predetermined fixture position. The fixture is an auxiliary structure for adjusting the coaxial three-mirror optical system, which is used to install and position the primary mirror back plate, and it ensures the stability and accuracy of the primary mirror back plate during installation.

[0062] 202. Connect the primary mirror to the primary mirror back plate so that the optical axis of the primary mirror coincides with the mechanical axis of the back plate, thereby completing the assembly of the primary mirror assembly;

[0063] In this embodiment, the flexible joint is used to connect the main mirror to the main mirror back plate; the flexible joint has a certain elasticity and adjustability. By adjusting the preload force and position of the flexible joint, the tilt and rotation of the main mirror can be accurately controlled, thereby ensuring that the optical axis of the main mirror and the mechanical axis of the back plate are completely coincident.

[0064] 203. Connect the primary mirror assembly to one end of the primary-secondary mirror connecting bracket;

[0065] In this embodiment, the primary-secondary mirror connecting bracket is an important element in the optical system for supporting and connecting the primary mirror and the secondary mirror, and its two ends are respectively connected to the primary mirror and the secondary mirror.

[0066] See also Figure 3 A third embodiment of the method for assembling and adjusting a coaxial three-mirror optical system according to the present invention includes:

[0067] 301. Obtain primary mirror parameters and secondary mirror parameters;

[0068] In this embodiment, firstly, detailed parameters of the primary mirror and the secondary mirror need to be collected and obtained, including but not limited to the curvature radius, focal length, aperture, material refractive index, thickness, and surface treatment of the mirror surface.

[0069] 302. According to the primary mirror parameters and the secondary mirror parameters, optical simulation is performed on the primary and secondary mirror systems using optical design software to obtain primary image plane light path simulation data;

[0070] In this embodiment, after obtaining the parameters of the primary mirror and the secondary mirror, the optical design software (such as CodeV) can be used to perform optical simulation on the primary and secondary mirror system; this process usually includes the steps of establishing an optical model, inputting lens parameters, setting the light source and detector, etc.; the optical design software simulates the primary image plane light path of the primary and secondary mirror system, obtains the primary image plane light path simulation data, and thus analyzes the Zenike coefficient of its image plane.

[0071] See also Figure 4 A fourth embodiment of the method for assembling and adjusting a coaxial three-mirror optical system according to the present invention includes:

[0072] 401. Install the secondary mirror at the other end of the primary-secondary mirror connecting bracket, and adjust the primary mirror assembly and the secondary mirror to form a primary-secondary mirror system;

[0073] In this embodiment, the secondary mirror is installed to the other end of the primary-secondary mirror connecting bracket through the secondary mirror adjustment pad, and the relative position and angle of the primary mirror assembly and the secondary mirror are adjusted to ensure that the position and angle of the secondary mirror match the design requirements, thereby preliminarily forming a primary-secondary mirror system that meets the design requirements.

[0074] 402. Perform optical testing on the primary and secondary mirror systems to obtain primary image plane optical path data;

[0075] In this embodiment, after the primary and secondary mirror systems are constructed, an interferometer is used to perform an optical test on them, and a first image plane interference pattern is collected to obtain primary image plane optical path data.

[0076] See also Figure 5 A fifth embodiment of the method for assembling and adjusting a coaxial three-mirror optical system according to the present invention includes:

[0077] 501. Compare and analyze the primary image plane light path simulation data and the primary image plane light path data to obtain difference data;

[0078] In this embodiment, the primary image plane light path simulation data obtained by optical design software is compared and analyzed with the primary image plane light path data obtained by actual testing to obtain difference data, which reflects the deviation between the actual system and the designed system.

[0079] 502. Analyze the difference data using optical software to obtain adjustment data;

[0080] In this embodiment, after obtaining the difference data, it is necessary to use optical software to analyze these data and calculate the corresponding adjustment data. The adjustment data includes the translation and rotation direction and movement amount of the secondary mirror. The adjustment data is used to provide a basis for subsequent installation and adjustment work.

[0081] 503. Adjust the secondary mirror according to the adjustment data to complete the optical path construction of the primary and secondary mirror system;

[0082] In this embodiment, the secondary mirror is fine-tuned according to the adjustment data, usually by grinding the secondary mirror adjustment pad to adjust the angle and translation distance of the secondary mirror; during the adjustment process, its optical data is monitored in real time to ensure that a primary-secondary mirror system that meets the design requirements can be obtained in the end.

[0083] See also Figure 6 The sixth embodiment of the method for assembling and adjusting the coaxial three-mirror optical system in the embodiment of the present invention comprises:

[0084] The folding mirror assembly includes an L-mirror, a reflector, and mechanical mountings;

[0085] In this embodiment, the folding mirror assembly is composed of an L mirror, a reflector and a mechanical mounting part, wherein the L mirror includes a first sub-reflector and a second sub-reflector spliced ​​together on two sides; the L mirror and the reflector are respectively installed on two workstations of the mechanical mounting part, and the light incident on the folding mirror assembly will be reflected between the L mirror and the reflector; when installing the folding mirror assembly, the angle tolerance of the mechanical mounting surface needs to be strictly controlled.

[0086] 601. Install the L mirror on the L mirror station of the mechanical mounting part, and install the reflector on the reflector station of the mechanical mounting part to complete the assembly of the folding mirror assembly;

[0087] In this embodiment, it is first necessary to accurately install the L mirror on the L mirror position of the mechanical mounting part, and install the reflector on the reflector position of the mechanical mounting part, ensuring that the position and angle of the L mirror and the reflector meet the design requirements. Through this step, the combination of the folding mirror assembly is completed.

[0088] 602. Install the folding mirror assembly on the rear side of the main mirror assembly;

[0089] In this embodiment, after the folding mirror assembly is assembled, it is installed on the rear side of the main mirror assembly, and the mechanical mounting parts are combined with the main mirror back plate, so that the folding mirror assembly can be fixed on the rear side of the main mirror assembly; because the three mirrors need to be installed at the interface of the folding mirror assembly, the folding mirror assembly needs to be installed first.

[0090] See also Figure 7 The seventh embodiment of the method for assembling and adjusting the coaxial three-mirror optical system in the embodiment of the present invention comprises:

[0091] 701. Install the three mirrors at the interface of the folding mirror assembly;

[0092] In this embodiment, the folding mirror assembly interface refers to the three-mirror station on the mechanical mounting part, and the three mirrors are installed at the folding mirror assembly interface through the three-mirror adjustment pad; Fig.11 After the three mirrors are installed at the interface of the folding mirror assembly, the movement path of the light emitted from the secondary mirror and injected into the folding mirror assembly can be specifically as follows: the secondary mirror emits the light, which is reflected by the first sub-reflector to the three mirrors, and the three mirrors reflect the light back to the first sub-reflector, and the first sub-reflector reflects the light to the reflector, and the reflector reflects the light to the second sub-reflector, and the second sub-reflector finally reflects the light out of the folding mirror assembly; the light is reflected 5 times between the folding mirror assembly and the three mirrors and finally emitted.

[0093] 702. Use optical design software to perform optical simulation on the three mirrors to obtain secondary image plane light path simulation data;

[0094] In this embodiment, after the three mirrors are installed in place, it is necessary to use optical design software to perform optical simulation on them, predict the impact of the three mirrors on the optical path, and obtain simulation data of the secondary image plane optical path.

[0095] 703. Perform optical testing on the three mirrors to obtain secondary image plane optical path data;

[0096] In this embodiment, actual optical testing is performed on the three mirrors, and the second image plane interference pattern is collected to obtain secondary image plane optical path data.

[0097] 704. Compare the secondary image plane light path simulation data with the secondary image plane light path data to obtain three-mirror difference data;

[0098] In this embodiment, the primary image plane light path simulation data obtained by optical design software is compared and analyzed with the primary image plane light path data obtained by actual testing to obtain three-mirror difference data.

[0099] 705. Analyze the difference data of the three mirrors by using optical software to obtain the adjustment data of the three mirrors;

[0100] In this embodiment, after obtaining the difference data, it is necessary to use optical software to analyze these data and calculate the corresponding three-mirror adjustment data. The adjustment data may include the position adjustment amount, angle adjustment amount, etc. of the three mirrors.

[0101] 706. Use the three-mirror adjustment data to adjust the three mirrors, connect the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror, and complete the construction of the coaxial three-mirror optical system;

[0102] In this embodiment, the three-mirror adjustment pad is repaired according to the three-mirror adjustment data so that the full-field wave aberration RMS value of the coaxial three-mirror remote sensing optical system is better than 1 / 11λ (λ=532.8nm); it should be noted that since the sensitivity of the three mirrors is too low, it is necessary to fine-tune the secondary mirror to assist in the adjustment of the three mirrors; after the three mirrors are adjusted, the optical paths between the primary and secondary mirror systems, the three mirrors and the folding mirror are accurately connected to complete the construction of the coaxial three-mirror optical system.

[0103] See also Figure 8 The eighth embodiment of the method for assembling and adjusting the coaxial three-mirror optical system in the embodiment of the present invention comprises:

[0104] The coaxial three-mirror optical system also includes a reference cubic prism and a prism seat;

[0105] In this embodiment, the reference cubic prism has three mutually perpendicular planes, which play a key positioning and calibration role in the installation process. The reference cubic prism is used to determine the optical axis, horizontal axis and vertical axis of the optical system, thereby ensuring the accuracy and stability of the entire system; the prism seat is used to fix and support the reference cubic prism. By repairing the prism seat, the position and angle of the reference cubic prism can be further adjusted to meet the design requirements of the optical system; it should be noted that in the invention scheme, since the primary mirror, secondary mirror and third mirror are not on the same optical axis, the reference cubic prism is not used to assist the installation of the three mirrors, but the reference cubic prism is used to mark the optical axis. The marked optical axis can be used as a reference for subsequent maintenance and inspection of the system.

[0106] 801. Preliminarily assemble the reference cubic prism on the side of the primary mirror assembly through the prism seat;

[0107] In this embodiment, the prism seat is mounted on the side of the primary mirror back plate, and then the reference cubic prism is placed in the prism seat and ensured to be initially fixed.

[0108] 802. Repair and polish the prism seat, adjust the position and posture of the prism seat, and make the three mutually perpendicular planes in the reference cubic prism parallel to the optical axis, horizontal axis and vertical axis of the primary mirror assembly respectively;

[0109] In this embodiment, an optical measuring instrument or a laser rangefinder is first used to detect the relative positions of the three planes of the reference cubic prism and the axis of the primary mirror assembly, and then the prism seat is appropriately repaired according to the measurement results until the three planes of the reference cubic prism are respectively parallel to the optical axis, the horizontal axis and the vertical axis of the primary mirror assembly.

[0110] 803. Mark the optical axis of the coaxial three-mirror optical system by using a reference cubic prism to obtain a marked coaxial three-mirror optical system;

[0111] In this embodiment, the main purpose of the optical axis mark is to mark the optical axes of each optical element in the coaxial three-mirror optical system; by observing or measuring the light reflected by the cubic prism, it is determined whether there is a deviation in the optical axis of the optical system; according to the observed deviation, each element in the optical system is adjusted, and the adjustment is completed to obtain a marked coaxial three-mirror optical system.

[0112] See also Fig. 9 The ninth embodiment of the method for assembling and adjusting the coaxial three-mirror optical system in the embodiment of the present invention includes:

[0113] The coaxial three-mirror optical system also includes a focal plane assembly;

[0114] In this embodiment, two focal plane reflectors are spliced ​​together to form a focal plane assembly, and the focal plane assembly is used to assist the imaging of the coaxial three-mirror optical system.

[0115] 901. Install the focal plane assembly at the optical path focus at the rear end of the folding mirror assembly;

[0116] In this embodiment, a measuring tool (such as an optical measuring instrument, a laser rangefinder, etc.) is first used to determine the focal position of the rear optical path of the folding mirror assembly, and then the focal plane assembly is installed at a predetermined position. In one embodiment, a CMOS module can be installed on the focal plane assembly, the CMOS module is electrically connected to the focal plane assembly, and corresponding image data is generated by the CMOS module to better observe the imaging of the coaxial three-mirror optical system.

[0117] 902. Perform imaging adjustment on the coaxial three-mirror optical system by using a focal plane assembly to obtain the coaxial three-mirror optical system after imaging adjustment;

[0118] In this embodiment, by adjusting the position or angle of the focal plane assembly, the light can be roughly focused on the expected image plane, thereby obtaining a coaxial three-mirror optical system after imaging adjustment.

[0119] See also Fig.10 The tenth embodiment of the method for assembling and adjusting the coaxial three-mirror optical system in the embodiment of the present invention comprises:

[0120] 1001. Test the imaging quality of the coaxial three-mirror optical system to obtain a test result;

[0121] In this embodiment, it is necessary to test the imaging quality of the coaxial three-mirror optical system, and the test includes: using a high-resolution tester or a standard resolution board to evaluate the resolution capability of the system, checking whether there is obvious barrel or pincushion distortion in the imaging, evaluating the chromatic aberration of the system at different wavelengths, measuring the contrast between light and dark parts in the image, and checking the focus of the image at different field of view angles.

[0122] 1002. If the test result meets the preset qualified conditions, the installation and adjustment of the coaxial three-mirror optical system is completed.

[0123] In this embodiment, if the test result shows that the imaging quality of the coaxial three-mirror optical system meets the preset qualified conditions, then it can be considered that the installation and adjustment of the coaxial three-mirror optical system has been completed.

[0124] Finally, it should be noted that the above description is only a preferred example of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for assembling a coaxial three-mirror optical system, characterized in that: The coaxial three-mirror optical system comprises: a primary mirror assembly, a primary-secondary mirror connecting bracket, a secondary mirror, a three-mirror and a folding mirror assembly; the assembly and adjustment method of the coaxial three-mirror optical system comprises: Fix the primary mirror assembly on the fixture, and connect the primary mirror assembly to one end of the primary-secondary mirror connecting bracket; Use optical design software to simulate and analyze the primary and secondary mirror systems to obtain the primary image plane light path simulation data; The secondary mirror is mounted and adjusted at the other end of the primary-secondary mirror connection bracket, and an optical test is performed on the secondary mirror to obtain primary image plane optical path data; According to the primary image plane light path simulation data and the primary image plane light path data, the adjustment data is obtained, and the secondary mirror is installed and adjusted according to the adjustment data to complete the construction of the primary and secondary mirror system; Install the folding mirror assembly on the rear side of the main mirror assembly; Install the three mirrors at the interface of the folding mirror assembly, connect the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror, and complete the construction of the coaxial three-mirror optical system; The coaxial three-mirror optical system is tested to obtain a test result. If the test result meets the preset qualified conditions, the installation and adjustment of the coaxial three-mirror optical system is completed.

2. The method for assembling and adjusting a coaxial three-mirror optical system according to claim 1, characterized in that: The main mirror assembly comprises a main mirror and a main mirror back plate; the method of fixing the main mirror assembly on the tooling and connecting the main mirror assembly to one end of the main-secondary mirror connecting bracket comprises: Install the primary mirror back plate on the tooling; Connect the primary mirror to the primary mirror back plate so that the optical axis of the primary mirror coincides with the mechanical axis of the back plate, thus completing the assembly of the primary mirror assembly; Connect the primary mirror assembly to one end of the primary-secondary mirror connecting bracket.

3. The method for assembling and adjusting the coaxial three-mirror optical system according to claim 1, characterized in that: The optical design software is used to simulate and analyze the primary and secondary mirror systems to obtain the primary image plane light path simulation data, including: Get the primary mirror parameters and the secondary mirror parameters; According to the parameters of the primary mirror and the secondary mirror, the optical design software is used to perform optical simulation on the primary and secondary mirror systems to obtain the primary image plane light path simulation data.

4. The method for assembling and adjusting the coaxial three-mirror optical system according to claim 1, characterized in that: The secondary mirror is mounted on the other end of the primary-secondary mirror connection bracket, and an optical test is performed on the secondary mirror to obtain primary image plane optical path data, including: The secondary mirror is mounted on the other end of the primary-secondary mirror connecting bracket, and the primary mirror assembly and the secondary mirror are adjusted to form a primary-secondary mirror system; Conduct optical tests on the primary and secondary mirror systems to obtain primary image plane optical path data.

5. The method for assembling and adjusting the coaxial three-mirror optical system according to claim 1, characterized in that: The method obtains adjustment data according to the primary image plane light path simulation data and the primary image plane light path data, and adjusts the secondary mirror according to the adjustment data to complete the construction of the primary and secondary mirror system, including: Compare and analyze the primary image plane light path simulation data and the primary image plane light path data to obtain difference data; The difference data are analyzed using optical software to obtain adjustment data; The secondary mirror is installed and adjusted according to the adjustment data to complete the optical path construction of the primary and secondary mirror system.

6. The method for assembling and adjusting the coaxial three-mirror optical system according to claim 1, characterized in that: The folding mirror assembly comprises an L mirror, a reflector and a mechanical mounting member; the folding mirror assembly is mounted on the rear side of the main mirror assembly, comprising: Install the L mirror on the L mirror station of the mechanical mounting part, and install the reflector on the reflector station of the mechanical mounting part to complete the assembly of the folding mirror assembly; Install the folding mirror assembly on the rear side of the main mirror assembly.

7. The method for assembling and adjusting a coaxial three-mirror optical system according to claim 1, characterized in that: The three mirrors are installed at the interface of the folding mirror assembly, and the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror are connected to complete the construction of the coaxial three-mirror optical system, including: installing the three mirrors at the interface of the folding mirror assembly; Use optical design software to perform optical simulation on the three mirrors to obtain the secondary image plane light path simulation data; perform optical testing on the three mirrors to obtain the secondary image plane light path data; Compare the secondary image plane light path simulation data with the secondary image plane light path data to obtain three-mirror difference data; Use optical software to analyze the difference data of the three mirrors and obtain the adjustment data of the three mirrors; The three mirrors are adjusted using the three-mirror adjustment data, and the optical paths of the primary and secondary mirror systems, three mirrors and the folding mirror are connected to complete the construction of the coaxial three-mirror optical system.

8. The method for assembling and adjusting a coaxial three-mirror optical system according to claim 1, characterized in that: The coaxial three-mirror optical system also includes a reference cubic prism and a prism seat; the three mirrors are installed at the interface of the folding mirror assembly, and the optical paths of the primary and secondary mirror systems, the three mirrors and the folding mirror are connected to complete the construction of the coaxial three-mirror optical system, including: Assemble the reference cubic prism on the side of the primary mirror assembly through a prism mount; The prism seat is repaired and the position and posture of the prism seat are adjusted so that the three mutually perpendicular planes in the reference cubic prism are respectively parallel to the optical axis, horizontal axis and vertical axis of the primary mirror assembly; the optical axis of the coaxial three-mirror optical system is marked using the reference cubic prism to obtain the marked coaxial three-mirror optical system.

9. The method for assembling and adjusting the coaxial three-mirror optical system according to claim 8, characterized in that: The coaxial three-mirror optical system further includes a focal plane assembly; after the optical axis of the coaxial three-mirror optical system is marked by using a reference cubic prism to obtain the marked coaxial three-mirror optical system, the method comprises: The focal plane assembly is installed at the focus of the optical path at the rear end of the folding mirror assembly; The coaxial three-mirror optical system is image-adjusted by using a focal plane assembly to obtain the coaxial three-mirror optical system after image adjustment.

10. The method for assembling and adjusting the coaxial three-mirror optical system according to claim 1, characterized in that: The coaxial three-mirror optical system is tested to obtain a test result. If the test result meets a preset qualified condition, the coaxial three-mirror optical system is assembled and adjusted, including: The imaging quality of the coaxial three-mirror optical system is tested and the test results are obtained; If the test results meet the preset qualified conditions, the installation and adjustment of the coaxial three-mirror optical system is completed.

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