Secondary mirror supporting structure and common-aperture optical system installation method using same

Abstract

The invention relates to the technical field of optical-mechanical structures, in particular to a secondary mirror supporting structure and a common-aperture optical system mounting method applying the same, and the secondary mirror supporting structure comprises a secondary mirror bracket, a secondary mirror frame and a flexible hinge; on one hand, through the epoxy glue injection hole and the silicone rubber injection hole, the stability of the angle posture of the secondary mirror can be improved in a manner of jointly fixing the secondary mirror by using epoxy glue and silicone rubber; on the other hand, the flexible hinge is used for elastically supporting the secondary mirror, stress caused by difference of thermal expansion coefficients of the secondary mirror and the secondary mirror frame can be absorbed, the stability of the angle posture of the secondary mirror is further improved, and actual experiment requirements are met.

Description

Technical Field

[0001] The present invention relates to the technical field of opto-mechanical structures, and particularly to a secondary mirror support structure and a method for installing a common-aperture optical system using this structure. Background Art

[0002] With the continuous development of the requirements for recording actual scene images of various targets, attitude perception, radiation characteristic measurement, etc., the functions of optoelectronic imaging systems are becoming increasingly diverse and their performance is becoming increasingly improved; the previous single-spectrum optical systems cannot meet the requirements for observing multiple targets, and multi-spectrum common-aperture optical systems are increasingly widely used.

[0003] Its characteristic is that the optical paths of different bands share the primary mirror and the secondary mirror. As one of the core components of the shared optical path, the secondary mirror has increasingly high requirements for attitude stability to ensure tracking and measurement accuracy; the secondary mirror has changed from a simple reflection element in the past to a beam splitting element with both reflection and transmission functions, and both its front and back surfaces are working surfaces, and it can only be supported by the outer circumference.

[0004] Although the Chinese invention patent with the publication number CN110531482B provides a flexible and high-precision focusing mechanism for a secondary mirror assembly, which clamps and supports the secondary mirror through a secondary mirror base, since the secondary mirror still needs to work normally within a wide temperature range, the existing secondary mirror support structure cannot meet the stable and reliable support requirements of the secondary mirror.

[0005] At the same time, due to the use of multiple optical paths in the common-aperture optical system, the secondary mirror will be blocked and interfered with other optical paths during the installation and adjustment process, affecting the installation efficiency and reliability, and further reducing the operation reliability, and cannot meet the actual operation requirements. Summary of the Invention

[0006] The purpose of the present invention is to provide a secondary mirror support structure and a method for installing a common-aperture optical system using this structure to solve the problems existing in the above-mentioned prior art.

[0007] The solution of the present invention to the above technical problems: A secondary mirror support structure includes a secondary mirror frame, a secondary mirror ring and a flexible hinge; An optical path hole is provided on the secondary mirror frame, a secondary mirror mounting hole and a hinge mounting hole are provided on the secondary mirror ring, the hinge mounting hole is provided along the radial direction of the secondary mirror ring, the secondary mirror ring is connected to the secondary mirror frame, the optical path hole is coaxially arranged with the secondary mirror mounting hole, the fixed end of the flexible hinge is connected to the secondary mirror ring, and the flexible end of the flexible hinge passes through the inner wall of the secondary mirror mounting hole along the hinge mounting hole for supporting the secondary mirror arranged in the secondary mirror mounting hole; Epoxy glue injection holes are provided on the circumferential end surface of the flexible hinge, and silicone rubber injection holes are provided on the secondary mirror frame. The epoxy glue injection holes and the silicone rubber injection holes are both provided along the radial direction of the secondary mirror frame, and the epoxy glue injection holes and the silicone rubber injection holes are both communicated with the secondary mirror mounting holes.

[0008] Further defined, the flexible hinge includes a hinge fixing block and a flexible connecting block; The top of the hinge fixing block is connected to the secondary mirror frame, the bottom of the hinge fixing block is located in the hinge mounting hole, one end of the flexible connecting block is connected to the bottom of the hinge fixing block, the other end of the flexible connecting block is arranged along the length direction of the hinge fixing block, and the bottom of the flexible connecting block passes through the hinge mounting hole and extends into the secondary mirror mounting hole; an arc surface matching the circumferential end surface of the secondary mirror is provided at the bottom of the flexible connecting block; The epoxy glue injection hole extends from the top end of the hinge fixing block to the bottom surface of the flexible connecting block.

[0009] Further defined, the number of the epoxy glue injection holes and the number of the silicone rubber injection holes are both multiple, and the multiple epoxy glue injection holes and the multiple silicone rubber injection holes are both arranged in a circumferential array around the axis of the secondary mirror mounting hole, and the axes of the epoxy glue injection holes and the axes of the silicone rubber injection holes both pass through the center of gravity of the secondary mirror.

[0010] Further defined, the secondary mirror support structure further includes a secondary mirror retaining ring and a light shield; A retaining ring mounting groove is provided in the secondary mirror mounting hole, the secondary mirror retaining ring is arranged in the retaining ring mounting groove, and the inner diameter of the secondary mirror retaining ring is smaller than the inner diameter of the secondary mirror mounting hole; The light shield is arranged on the outer side of the secondary mirror frame and is detachably connected to the secondary mirror frame, and the secondary mirror retaining ring is close to the corresponding end surface of the light shield.

[0011] Further defined, a first mirror frame connecting block and a second mirror frame connecting block are provided on the circumferential end surface of the secondary mirror frame, a mirror frame connecting hole is provided on the first mirror frame connecting block, a mirror frame connecting hole and a connection positioning hole are provided on the second mirror frame connecting block, the number of the first mirror frame connecting blocks and the number of the second mirror frame connecting blocks are both at least two, and the first mirror frame connecting blocks and the second mirror frame connecting blocks are arranged in an array.

[0012] A method for installing a common-aperture optical system using the above secondary mirror support structure, characterized by comprising the following steps: S1. Level the main box body; S2. Install the primary mirror assembly and the secondary mirror support structure in the main box body respectively and determine the installation position of the secondary mirror support structure in the main box body; S3. Remove the secondary mirror frame connected to the secondary mirror, install a mid-wave infrared mirror box under the main box body, and complete the mid-wave infrared optical path piercing using a theodolite; S4. Use the theodolite to complete the visible light path penetration and connect the secondary mirror frame to the secondary mirror frame.

[0013] It is further defined that the step S specifically includes: S2.1. Place a plane reflector in front of the main box and a laser interferometer in the back of the main box. S2.2. Install the primary mirror assembly and secondary mirror support structure separately within the main housing. Mount the secondary mirror on the secondary mirror frame, placing the primary mirror assembly toward the rear of the main housing and the secondary mirror support structure toward the front of the main housing. S2.3. Adjust the laser interferometer and the plane mirror so that the laser interferometer measures the wave aberration at the primary image plane; S2.4. Adjust the installation position and angle of the secondary mirror support structure and the main housing so that the wavefront aberration at the primary image plane meets the set specifications. S2.5. Determine the installation position of the secondary mirror frame in the main box and remove the plane mirror and laser interferometer.

[0014] It is further defined that the specific steps of installing the secondary mirror on the secondary mirror frame are: Insert the secondary mirror into the secondary mirror mounting hole so that the bottom of the flexible hinge contacts the peripheral end surface of the secondary mirror; Use the secondary mirror pressure ring to insert into the pressure ring installation groove to limit the secondary mirror; Injecting epoxy glue through the epoxy glue injection hole to form a plurality of epoxy glue spots on the peripheral end surface of the secondary mirror; After the epoxy glue spots are cured, the surface shape of the secondary mirror is checked to see if it is qualified. If it is unqualified, the epoxy glue spots are removed and the epoxy glue is re-injected through the epoxy glue injection hole. If it is qualified, silicone rubber is injected through the silicone rubber injection hole to form multiple silicone rubber spots on the peripheral end surface of the secondary mirror. After the silicone rubber spots are cured, check whether the surface shape of the secondary mirror is qualified. If not, remove the silicone rubber spots and re-inject the silicone rubber through the silicone rubber injection hole; if qualified, connect the light shield to the secondary mirror frame.

[0015] It is further defined that the step S specifically includes: S3.1. Remove the secondary mirror frame connected to the secondary mirror holder, and remove the laser interferometer and plane mirror. S3.2. Install the primary mirror crosshair reticle on the back of the primary mirror assembly. Install the first-wave infrared folding mirror assembly on the main housing. Place the first theodolite behind the main housing, with the first-wave infrared folding mirror assembly facing the secondary mirror mount and the first theodolite facing the primary mirror crosshair reticle. S3.3. Install a medium-wave infrared mirror box below the main box; S3.4. Install the second mid-wave infrared anastigmat component and the mid-wave infrared lens group bracket in the mid-wave infrared camera box, set up the second theodolite behind the mid-wave infrared camera box, and install the crosshair reticle of the mid-wave infrared lens group on the mid-wave infrared lens group bracket, so that the second mid-wave infrared anastigmat component faces the first mid-wave infrared anastigmat component; S3.5. Use the first theodolite to aim at the crosshair reticle of the primary mirror, so that the reflected image of the crosshair of the crosshair reticle of the primary mirror coincides with the crosshair of the field center of the first theodolite; S3.6. By adjusting the height of the crosshair reticle of the mid-wave infrared lens group, make the reflected image of the crosshair of the crosshair reticle of the mid-wave infrared lens group coincide with the crosshair of the field center of the first theodolite.

[0016] Further defined, the step S specifically includes: S4.1. Remove the crosshair reticle of the mid-wave infrared lens group and the crosshair reticle of the primary mirror; S4.2. Adjust the second theodolite to make the second theodolite self-align with the first theodolite, and remove the first theodolite; S4.3. Install the first visible light anastigmat component in the main box body, so that the first visible light anastigmat component faces the back of the primary mirror component; S4.4. Install the first visible light lens group support and the second visible light lens group bracket on the top of the main box body, so that the first visible light lens group support and the second visible light lens group bracket are respectively located on the opposite sides of the primary mirror component; S4.5. Install the crosshair reticle of the first visible light lens group and the second visible light anastigmat component on the first visible light lens group support, and install the crosshair reticle of the second visible light lens group on the second visible light lens group bracket, so that both the crosshair reticle of the first visible light lens group and the crosshair reticle of the second visible light lens group are opposite to the second visible light anastigmat component; S4.6. Adjust the first visible light lens group support and the second visible light lens group bracket respectively, so that the reflected image of the crosshair of the crosshair reticle of the first visible light lens group and the reflected image of the crosshair of the crosshair reticle of the second visible light lens group both coincide with the crosshair of the field center of the second theodolite, and determine the installation positions of the first visible light lens group support and the second visible light lens group bracket; S4.7. Determine the installation positions of the secondary mirror frame and the secondary mirror holder by the cooperation of the positioning pin and the connecting positioning hole; connect the secondary mirror frame installed with the secondary mirror and the light shield to the secondary mirror holder through the mirror holder connecting hole.

[0017] The beneficial effects of the present invention are as follows: 1. On the one hand, through the epoxy glue injection holes and silicone rubber injection holes of the present invention, by using the combined fixation of epoxy glue and silicone rubber for the secondary mirror, the stability of the angular attitude of the secondary mirror can be improved. On the other hand, by using flexible hinges to elastically support the secondary mirror, the stress caused by the difference in the coefficient of thermal expansion between the secondary mirror and the secondary mirror frame can be absorbed, further improving the stability of the angular attitude of the secondary mirror to meet the actual experimental requirements.

[0018] 2. The present invention uses the detachable connection method between the secondary mirror frame and the secondary mirror holder. First, connect the secondary mirror holder to the secondary mirror frame to complete the installation of the secondary mirror and determine the installation position. Then, use a theodolite to complete the through - hole of the mid - wave infrared optical path and the visible optical path by adjusting the optical path in the main box body and the mid - wave infrared mirror box, thereby reducing the eccentricity error and angular error of each optical path element. At the same time, through the cooperation of the connection positioning holes and positioning pins, the secondary mirror frame with the secondary mirror installed is accurately installed, meeting the wave aberration requirements and improving the operation efficiency. Brief Description of the Drawings

[0019] Figure 1 Schematic diagram of the secondary mirror support structure of the present invention; Figure 2 Cross - sectional view of the secondary mirror support structure of the present invention; Figure 3 Schematic diagram of the secondary mirror frame structure of the present invention; Figure 4 For Figure 2 Enlarged schematic diagram of part A in Figure 5 Schematic diagram of the flexible hinge structure of the present invention; Figure 6 Installation and adjustment optical path diagram of the primary mirror assembly and the secondary mirror support structure of the present invention; Figure 7 Mid - wave infrared optical path through - hole process optical path diagram of the present invention; Figure 8 Visible optical path through - hole process optical path diagram of the present invention; Figure 9 Cross - sectional view of the common - aperture optical system of the present invention; In the figure, 100 - secondary mirror support structure; 111 - optical path hole; 110 - secondary mirror frame; 120 - secondary mirror housing; 121 - secondary mirror mounting hole; 122 - hinge mounting hole; 123 - silicone rubber injection hole; 124 - first mirror frame connection block; 125 - second mirror frame connection block; 126 - mirror frame connection hole; 127 - connection positioning hole; 128 - hinge connection block; 129 - light shield connection block; 130 - secondary mirror; 140 - secondary mirror retaining ring; 150 - light shield; 200 - flexible hinge; 210 - hinge fixing block; 220 - flexible connection block; 221 - arc surface; 230 - epoxy glue injection hole; 300 - main housing; 301 - secondary mirror group gasket; 310 - plane mirror; 311 - laser interferometer; 320 - primary mirror assembly; 321 - primary mirror; 322 - primary mirror support; 323 - primary mirror crosshair reticle; 330 - first wave infrared coudé mirror assembly; 331 - first theodolite; 340 - first visible light coudé mirror assembly; 350 - first visible light lens group support; 351 - first visible light lens group crosshair reticle; 352 - first visible light lens group support gasket; 353 - first visible light lens group; 360 - second visible light coudé mirror assembly; 370 - second visible light lens group support; 371 - second visible light lens group crosshair reticle; 372 - second visible light lens group support gasket; 373 - second visible light lens group; 400 - mid - wave infrared mirror box; 410 - second mid - wave infrared coudé mirror assembly; 411 - second theodolite; 420 - mid - wave infrared lens group support; 421 - mid - wave infrared lens group crosshair reticle; 422 - mid - wave infrared lens group support gasket; 423 - mid - wave infrared lens group. Detailed implementation mode

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Embodiment 1 Reference Figure 1 , the present invention provides a secondary mirror support structure, including a secondary mirror frame 110, a secondary mirror housing 120 and a flexible hinge 200; the secondary mirror housing 120 is connected to the secondary mirror 130 through the flexible hinge 200.

[0022] Specifically, for the convenience of connection, the secondary mirror frame 110 preferably has a mirror frame connection block provided on the circumferential end face of the secondary mirror frame 110, and a mirror frame connection hole 126 is opened on the mirror frame connection block.

[0023] Reference Figure 2, wherein, a circular optical path hole 111 is formed on the secondary mirror frame 110. Preferably, the optical path hole 111 is coaxially arranged with the secondary mirror frame 110. A secondary mirror mounting hole 121 matching the outer contour of the secondary mirror 130 is formed on the secondary mirror frame 120. Preferably, the secondary mirror mounting hole 121 is coaxially arranged with the secondary mirror frame 120; the secondary mirror frame 120 is connected to the secondary mirror frame 110, preferably a detachable connection. Optionally, the optical path hole 111 is sleeved outside one end face of the secondary mirror frame 120, so that the secondary mirror mounting hole 121 is coaxially arranged with the optical path hole 111.

[0024] Preferably, first mirror frame connection blocks 124 are arranged on the circumferential end face of the secondary mirror frame 120. The side end face of the first mirror frame connection block 124 faces the secondary mirror frame 110. A mirror frame connection hole 126 is formed on the first mirror frame connection block 124. Optionally, the secondary mirror frame 120 and the secondary mirror frame 110 can be connected by bolts; at this time, the number of the first mirror frame connection blocks 124 can be selected as four, and the four first mirror frame connection blocks 124 are arranged at equal intervals around the center of the secondary mirror frame 120 in a circumferential direction.

[0025] Reference Figure 3 , in order to facilitate the convenient and reliable detachable connection between the secondary mirror frame 120 and the secondary mirror frame 110, preferably, connection positioning holes 127 are further formed on some of the first mirror frame connection blocks 124, which is convenient for accurately and quickly positioning and connecting between the secondary mirror frame 110 and the secondary mirror frame 120 through positioning pins; the first mirror frame connection blocks 124 provided with the connection positioning holes 127 are used as the second mirror frame connection blocks 125. At this time, the number of the first mirror frame connection blocks 124 and the number of the second mirror frame connection blocks 125 can both be selected as two. Preferably, the first mirror frame connection blocks 124 and the second mirror frame connection blocks 125 are arranged at intervals in the circumferential direction.

[0026] Further explanation, hinge mounting holes 122 for mounting the flexible hinge 200 are formed on the circumferential end face of the secondary mirror frame 120. The hinge mounting holes 122 are formed along the radial direction of the secondary mirror frame 120. The hinge mounting holes 122 extend from the circumferential end face of the secondary mirror frame 120 to the inner wall of the secondary mirror frame 120, which is convenient for the bottom of the flexible hinge 200 to pass through the hinge mounting holes 122 and contact the circumferential end face of the secondary mirror 130.

[0027] The number of the hinge mounting holes 122 can be selected as multiple. The multiple hinge mounting holes 122 are arranged at equal intervals around the axis of the secondary mirror frame 120 in a circumferential direction. At the same time, the hinge mounting holes 122 are located between adjacent first mirror frame connection blocks 124 and second mirror frame connection blocks 125, which is convenient for disassembly and assembly.

[0028] Preferably, in order to facilitate the connection between the flexible hinge 200 and the secondary frame 120, a hinge connection block 128 is preferably provided on the circumferential end surface of the secondary frame 120. The hinge connection block 128 is close to the other end surface of the secondary frame 120, and the hinge connection block 128 is aligned with the hinge mounting hole 122. A connection hole is provided on the hinge connection block 128. Correspondingly, a matching connection hole is provided at the top of the flexible hinge 200, which is convenient for detachable connection with the flexible hinge 200 and ensures stable and reliable connection.

[0029] Furthermore, a silicone rubber injection hole 123 is also provided on the circumferential end surface of the secondary frame 120. The silicone rubber injection hole 123 is provided along the radial direction of the secondary frame 120, and the bottom of the silicone rubber injection hole 123 is communicated with the secondary mirror mounting hole 121. When the secondary mirror 130 is connected to the secondary mirror mounting hole 121, silicone rubber can be filled through the silicone rubber injection hole 123 at the position corresponding to the circumferential end surface of the secondary mirror 130, which is convenient for improving the attitude stability of the secondary mirror 130; the number of silicone rubber injection holes 123 can be selected as multiple, and the multiple silicone rubber injection holes 123 are arranged at equal intervals around the axis of the secondary frame 120. The number of silicone rubber injection holes 123 is preferably eight. At this time, silicone rubber injection holes 123 are provided on both opposite sides of the hinge mounting hole 122.

[0030] Reference Figure 4 and Figure 5 Furthermore, an epoxy resin injection hole 230 is provided on the flexible hinge 200. The epoxy resin injection hole 230 extends from the upper end surface of the flexible hinge 200 to the lower end surface of the flexible hinge 200, which is convenient for injecting epoxy resin through the epoxy resin injection hole 230 at the position corresponding to the circumferential side of the secondary mirror 130 during use, further providing the attitude stability of the secondary mirror 130.

[0031] Preferably, the axes of the epoxy resin injection hole 230 and the silicone rubber injection hole 123 both pass through the center of gravity of the secondary mirror 130, which is beneficial to ensuring the shape and stability of the secondary mirror surface 130; the combined fixing method using epoxy resin and silicone rubber can make the attitude stability of the secondary mirror angle 130 better than 5″, meeting the actual functional requirements.

[0032] Reference Figure 5 Furthermore, the flexible hinge 200 includes a hinge fixing block 210 and a flexible connection block 220.

[0033] The top of the hinge fixing block 210 is located above the hinge mounting hole 122 and is detachably connected to the hinge connection block 128, and the bottom of the hinge fixing block 210 is located in the hinge mounting hole 122; One end of the flexible connection block 220 is connected to the bottom of the hinge fixing block 210. The other end of the flexible connection block 220 is arranged along the length direction of the hinge fixing block 210. The bottom of the flexible connection block 220 passes through the hinge mounting hole 122 and extends into the secondary mirror mounting hole 121 for contacting the circumferential end face of the secondary mirror 130.

[0034] Preferably, in order to improve the connection reliability between the flexible connection block 220 and the secondary mirror 130, an arc surface 221 matching the circumferential end face of the secondary mirror 130 is arranged at the bottom of the flexible connection block 220, and the flexible hinge 200 is of an integral structure.

[0035] The flexible connection block 220 on the flexible hinge 200 can absorb the stress caused by the difference in thermal expansion coefficients between the secondary mirror 130 and the secondary mirror frame 120, and ensure that the surface shape of the secondary mirror 130 is not lower than λ / 40 (λ = 632.8 nm) under a temperature difference of ±40°C.

[0036] The epoxy glue injection hole 230 extends from the top end of the hinge fixing block 210 to the bottom surface of the flexible connection block 220. Since there is a gap between the flexible connection block 220 and the hinge fixing block 210, when injecting epoxy glue, an injection head is used to extend into the epoxy glue injection hole 230 for operation to ensure the accuracy and reliability of the glue injection amount and the glue injection position.

[0037] Reference Figure 1 、 Figure 2 and Figure 4 , further illustrate that the secondary mirror support structure further includes a secondary mirror retaining ring 140 and a light shield 150.

[0038] The light shield 150 is connected to the other end face of the secondary mirror frame 120, preferably a detachable connection. At this time, light shield connection blocks 129 can be arranged on the circumferential end face of the secondary mirror frame 120. The number of the light shield connection blocks 129 can be selected as four, and the four light shield connection blocks 129 are respectively arranged at the side ends of the corresponding hinge connection blocks 128.

[0039] To improve the installation reliability of the secondary mirror 130, preferably, a retaining ring installation groove is formed on the secondary mirror mounting hole 121, the retaining ring installation groove is close to the light shield 150, the inner diameter of the retaining ring installation groove is larger than the inner diameter of the secondary mirror mounting hole 121. When the circumferential end face of the secondary mirror 130 is matched with the secondary mirror mounting hole 121, the retaining ring installation groove is located outside the circumferential end face of the secondary mirror 130. At this time, the secondary mirror retaining ring 140 is matched with the retaining ring installation groove to squeeze the corresponding end face position of the secondary mirror 130 to limit the axial displacement of the secondary mirror 130 in the secondary mirror mounting hole 121.

[0040] Embodiment 2 Based on the secondary mirror support structure provided in Embodiment 1, this embodiment provides a method for installing a common aperture optical system using the secondary mirror support structure, including the following steps: S1. Level the main housing 300. S2. Install the primary mirror assembly 320 and the secondary mirror support structure 100 in the main housing 300 respectively and determine the installation position of the secondary mirror support structure 100 in the main housing 300. S3. Remove the secondary mirror frame 120 connected to the secondary mirror holder 110, install the mid-wave infrared mirror box 400 under the main housing 300, and complete the mid-wave infrared optical path passing through with a theodolite. S4. Complete the visible optical path passing through with a theodolite and connect the secondary mirror frame 120 to the secondary mirror holder 110.

[0041] Among them, the main housing 300 is usually placed on an air-bearing platform for leveling.

[0042] Further explanation, refer to Figure 6 , step S2 includes: S2.1. Place a plane mirror 310 in front of the main housing 300 and place a laser interferometer 311 behind the main housing 300.

[0043] S2.2. Install the primary mirror assembly 320 and the secondary mirror support structure 100 in the main housing 300 respectively, install the secondary mirror 130 on the secondary mirror frame 120, make the primary mirror assembly 320 close to the rear of the main housing 300, and make the secondary mirror support structure 100 close to the front of the main housing 300.

[0044] Specifically, the primary mirror assembly 320 includes a primary mirror 321 and a primary mirror support 322. The primary mirror support 322 is connected to the inside of the main housing 300, and the primary mirror support 322 is sleeved outside the primary mirror 321 and connected to the primary mirror 321.

[0045] The primary mirror 321 faces the secondary mirror support structure 100. The secondary mirror support structure 100 is connected to the inside of the main housing 300 through the secondary mirror holder 110. A connecting plate is provided inside the main housing 300, and a box inner hole is opened on the connecting plate. The secondary mirror holder 110 is connected to the connecting plate through the secondary mirror group gasket 301. The installation position of the secondary mirror holder 110 inside the main housing 300 is adjusted by adjusting the thickness of the secondary mirror group gasket 301.

[0046] S2.3. Adjust the laser interferometer 311 and the plane mirror 310 so that the laser interferometer 311 measures the wavefront aberration at the primary image plane.

[0047] Specifically, by repeatedly adjusting the pose of the laser interferometer 311 and the pose of the plane mirror 310, the laser interferometer 311 measures the wavefront aberration at the primary image plane.

[0048] S2.4. Adjust the installation position and installation angle of the secondary mirror support structure 100 and the main housing 300 so that the wavefront aberration at the primary image plane meets the set index.

[0049] Specifically, an adjustment gap is reserved between the secondary mirror frame 110 and the inner hole of the box body. The adjustment gap is, for example, 1 mm. By adjusting the position of the secondary mirror frame 110 and trimming the thickness of the secondary mirror group gasket 301, the wave aberration at the primary image plane meets the optical index requirements.

[0050] S2.5. Determine the installation position of the secondary mirror frame 110 in the main box body 300, and remove the plane mirror 310 and the laser interferometer 311.

[0051] Specifically, the secondary mirror frame 110 is firmly connected to the connecting plate through the mirror frame connecting block, and further determine the installation positions of the secondary mirror frame 120 and the secondary mirror 130 inside it.

[0052] Further explanation, the specific steps for installing the secondary mirror 130 on the secondary mirror frame 120 are as follows: Embed the secondary mirror 130 into the secondary mirror installation hole 121, and make the bottom of the flexible hinge 200 contact with the peripheral end face of the secondary mirror 130.

[0053] Use the secondary mirror retaining ring 140 to embed into the retaining ring installation groove for limiting the secondary mirror 130; Inject epoxy glue through the epoxy glue injection hole 230 to form four epoxy glue spots on the peripheral end face of the secondary mirror 130.

[0054] After the epoxy glue spots are cured, check whether the surface shape of the secondary mirror 130 is qualified. If it is not qualified, remove the epoxy glue spots and re-inject the epoxy glue through the epoxy glue injection hole 230; if it is qualified, inject silicone rubber through the silicone rubber injection hole 123 to form eight silicone rubber spots on the peripheral end face of the secondary mirror 130.

[0055] After the silicone rubber spots are cured, check whether the surface shape of the secondary mirror 130 is qualified. If it is not qualified, remove the silicone rubber spots and re-inject the silicone rubber through the silicone rubber injection hole 123; if it is qualified, connect the light shield 150 to the secondary mirror frame 120.

[0056] Further explanation, refer to Figure 7 , step S3 specifically includes: S3.1. Remove the secondary mirror frame 120 connected to the secondary mirror frame 110, and remove the laser interferometer 311 and the plane mirror 310.

[0057] Remove the secondary mirror frame 120, remove the positioning pins, and keep the connection between the secondary mirror frame 110 and the connecting plate.

[0058] S3.2. Install the main mirror crosshair reticle 323 on the back of the main mirror assembly 320, install the first wave infrared coudé mirror assembly 330 on the main housing 300, and place the first theodolite 331 behind the main housing 300, so that the first wave infrared coudé mirror assembly 330 faces the secondary mirror bracket 110 and the first theodolite 331 faces the main mirror crosshair reticle 323.

[0059] Install the main mirror crosshair reticle 323 behind the main mirror assembly 320. The normal direction passing through the center of the crosshairs of the main mirror crosshair reticle 323 represents the optical axis of the main mirror 321.

[0060] Install the first wave infrared coudé mirror assembly 330 inside the main housing 300. The first wave infrared coudé mirror assembly 330 is connected to the connecting plate, and the connecting plate is located between the first wave infrared coudé mirror assembly 330 and the secondary mirror bracket 110.

[0061] S3.3. Set the mid-wave infrared mirror box 400 below the main housing 300.

[0062] S3.4. Install the second mid-wave infrared coudé mirror assembly 410 and the mid-wave infrared lens group bracket 420 in the mid-wave infrared mirror box 400. Set the second theodolite 411 behind the mid-wave infrared mirror box 400, and install the mid-wave infrared lens group crosshair reticle 421 on the mid-wave infrared lens group bracket 420, so that the second mid-wave infrared coudé mirror assembly 410 faces the first wave infrared coudé mirror assembly 330.

[0063] Specifically, the second mid-wave infrared coudé mirror assembly 410 is installed inside the mid-wave infrared mirror box 400, near the front of the mid-wave infrared mirror box 400, and the second mid-wave infrared coudé mirror assembly 410 faces the first wave infrared coudé mirror assembly 330 above it.

[0064] The mid-wave infrared lens group bracket 420 is installed at the bottom inside the mid-wave infrared mirror box 400 through the mid-wave infrared lens group bracket gasket 422. The mid-wave infrared lens group crosshair reticle 421 is installed on the mid-wave infrared lens group bracket 420, and the mid-wave infrared lens group bracket 420 is located between the second mid-wave infrared coudé mirror assembly 410 and the second theodolite 411.

[0065] S3.5. Use the first theodolite 331 to aim at the main mirror crosshair reticle 323, so that the reflected image of the crosshairs of the main mirror crosshair reticle 323 coincides with the center crosshair of the field of view of the first theodolite 331.

[0066] Specifically, set up the first theodolite 331. The first theodolite 331 aims at the reticle of the main mirror 323, so that the reflected image of the reticle of the main mirror reticle 323 coincides with the crosshair at the center of the field of view of the first theodolite 331. At this time, the optical axis of the first theodolite 331 is the subsequent through-hole reference.

[0067] S3.6. By adjusting the height of the reticle of the mid-wave infrared lens group 421, make the reflected image of the reticle of the mid-wave infrared lens group reticle 421 coincide with the crosshair at the center of the field of view of the first theodolite 331.

[0068] Specifically, by trimming the thickness of the gasket 422 of the mid-wave infrared lens group bracket 420, make the reflected image of the reticle of the mid-wave infrared lens group reticle 421 coincide with the crosshair at the center of the field of view of the first theodolite 331, and determine the installation position of the mid-wave infrared lens group bracket 420 in the mid-wave infrared mirror box 400. For example, fix it with screws, and the mid-wave infrared optical path through-hole is completed.

[0069] Further explanation, refer to Figure 8 , step S4 specifically includes: S4.1. Remove the reticle of the mid-wave infrared lens group 421 and the reticle of the main mirror 323; S4.2. Adjust the second theodolite 411 to make the second theodolite 411 self-align with the first theodolite 331, and remove the first theodolite 331.

[0070] Specifically, after removing the reticle of the mid-wave infrared lens group 421 and the reticle of the main mirror 323, it is convenient for the second theodolite 411 to self-align with the first theodolite 331, so that the optical axis of the second theodolite 411 is used as the subsequent through-hole reference.

[0071] S4.3. Install the first visible light coudé mirror assembly 340 in the main box 300, so that the first visible light coudé mirror assembly 340 faces the back of the main mirror assembly 320.

[0072] S4.4. Install the first visible light lens group support 350 and the second visible light lens group bracket 370 on the top of the main box 300, so that the first visible light lens group support 350 and the second visible light lens group bracket 370 are respectively located on the opposite sides of the main mirror assembly 320.

[0073] Specifically, the first visible light lens group support 350 and the second visible light lens group support 370 are installed on the top outside of the main box body 300. The first visible light lens group support 350 is connected to the main box body 300 through the first visible light lens group support gasket 352, and the second visible light lens group support 370 is connected to the main box body 300 through the second visible light lens group support gasket 372, so that the first visible light lens group support 350 and the second visible light lens group support 370 are located on the left and right sides of the main mirror assembly 320.

[0074] S4.5. Install the first visible light lens group reticle 351 and the second visible light anastigmat 360 on the first visible light lens group support 350, and install the second visible light lens group reticle 371 on the second visible light lens group support 370, so that both the first visible light lens group reticle 351 and the second visible light lens group reticle 371 face the second visible light anastigmat 360.

[0075] Specifically, the first visible light lens group reticle 351 is horizontally connected to the first visible light lens group support 350, and the second visible light anastigmat 360 is installed above the first visible light lens group reticle 351; the second visible light lens group reticle 371 is installed on the second visible light lens group support 370, and the second visible light lens group reticle 371 is vertically arranged on one side of the second visible light anastigmat 360.

[0076] S4.6. Adjust the first visible light lens group support 350 and the second visible light lens group support 370 respectively, so that the crosshair reflection images of the first visible light lens group reticle 351 and the second visible light lens group reticle 371 both coincide with the crosshair of the field center of the second theodolite 411, and determine the installation positions of the first visible light lens group support 350 and the second visible light lens group support 370.

[0077] Specifically, by trimming the thicknesses of the first visible light lens group support gasket 352 and the second visible light lens group support gasket 372, make the crosshair reflection images of the first visible light lens group reticle 351 and the second visible light lens group reticle 371 both coincide with the crosshair of the field center of the second theodolite 411, and determine the installation positions of the first visible light lens group support 350 and the second visible light lens group support 370 on the top of the main box body 300, and the visible light path passing through the center is completed.

[0078] S4.7. Determine the installation positions of the secondary mirror frame 120 and the secondary mirror support 110 through the cooperation of the positioning pin and the connecting positioning hole 127; connect the secondary mirror frame 120 installed with the secondary mirror 130 and the light shield 150 to the secondary mirror support 110 through the mirror support connection hole 126.

[0079] Reference Figure 9 After the optical path passes through the center, remove the second theodolite 411, and remove the crosshair reticle 371 of the second visible light lens group and the crosshair reticle 351 of the first visible light lens group. Subsequently, according to the usage requirements, select to install the mid-wave infrared lens group 423 on the mid-wave infrared lens group bracket 420, install the first visible light lens group 353 on the first visible light lens group support 350, and install the second visible light lens group 373 on the second visible light lens group bracket 370.

[0080] The eccentric error of each optical path component can be no more than 0.02 mm and the angular error can be no more than 10〞 by using the theodolite self-collimation method to pass through the center; the secondary mirror 130 is reset by the positioning pin, and on the premise of ensuring the realization of the self-collimation process, it still meets the system wave aberration requirements.

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the present invention; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present invention.

Claims

1. A secondary mirror support structure, characterized in that, It includes a secondary mirror frame (110), a secondary mirror lens frame (120) and a flexible hinge (200); An optical path hole (111) is provided on the secondary mirror frame (110), a secondary mirror mounting hole (121) and a hinge mounting hole (122) are provided on the secondary mirror lens frame (120), the hinge mounting hole (122) is provided along the radial direction of the secondary mirror lens frame (120), the secondary mirror lens frame (120) is connected to the secondary mirror frame (110), the optical path hole (111) and the secondary mirror mounting hole (121) are coaxially arranged, the fixed end of the flexible hinge (200) is connected to the secondary mirror lens frame (120), and the flexible end of the flexible hinge (200) passes through the inner wall of the secondary mirror mounting hole (121) along the hinge mounting hole (122) for supporting a secondary mirror (130) arranged in the secondary mirror mounting hole (121); An epoxy glue injection hole (230) is provided on the circumferential end face of the flexible hinge (200), a silicone rubber injection hole (123) is provided on the secondary mirror lens frame (120), both the epoxy glue injection hole (230) and the silicone rubber injection hole (123) are provided along the radial direction of the secondary mirror lens frame (120), and both the epoxy glue injection hole (230) and the silicone rubber injection hole (123) are communicated with the secondary mirror mounting hole (121).

2. The secondary mirror support structure according to claim 1, characterized in that, The flexible hinge (200) includes a hinge fixing block (210) and a flexible connecting block (220); The top of the hinge fixing block (210) is connected to the secondary mirror lens frame (120), the bottom of the hinge fixing block (210) is located in the hinge mounting hole (122), one end of the flexible connecting block (220) is connected to the bottom of the hinge fixing block (210), the other end of the flexible connecting block (220) is arranged along the length direction of the hinge fixing block (210), and the bottom of the flexible connecting block (220) passes through the hinge mounting hole (122) and extends into the secondary mirror mounting hole (121); an arc surface (221) matching the circumferential end face of the secondary mirror (130) is provided at the bottom of the flexible connecting block (220); The epoxy glue injection hole (230) extends from the top end of the hinge fixing block (210) to the bottom surface of the flexible connecting block (220).

3. The secondary mirror support structure according to claim 1, wherein The number of the epoxy glue injection holes (230) and the number of the silicone rubber injection holes (123) are both multiple, and the multiple epoxy glue injection holes (230) and the multiple silicone rubber injection holes (123) are both arranged in a circumferential array around the axis of the secondary mirror mounting hole (121), and the axes of the epoxy glue injection holes (230) and the axes of the silicone rubber injection holes (123) both pass through the center of gravity of the secondary mirror (130).

4. The secondary mirror support structure according to claim 3, characterized in that, The secondary mirror support structure further includes a secondary mirror retaining ring (140) and a light shield (150); A retaining ring mounting groove is provided in the secondary mirror mounting hole (121), the secondary mirror retaining ring (140) is arranged in the retaining ring mounting groove, and the inner diameter of the secondary mirror retaining ring (140) is smaller than the inner diameter of the secondary mirror mounting hole (121); The light shield (150) is arranged on the outer side of the secondary mirror lens frame (120) and is detachably connected to the secondary mirror lens frame (120), and the secondary mirror retaining ring (140) is close to the corresponding end face of the light shield (150).

5. The secondary mirror support structure according to claim 4, characterized in that, On the circumferential side end face of the secondary frame (120), a first frame connecting block (124) and a second frame connecting block (125) are provided. A frame connecting hole (126) is formed on the first frame connecting block (124), and a frame connecting hole (126) and a connecting positioning hole (127) are formed on the second frame connecting block (125). The number of the first frame connecting blocks (124) and the number of the second frame connecting blocks (125) are both at least two, and the first frame connecting blocks (124) and the second frame connecting blocks (125) are arranged in an array.

6. A method for installing a common-aperture optical system using the secondary mirror support structure according to claim 5, characterized in that, It includes the following steps: S1. Level the main box body (300); S2. Install the main mirror assembly (320) and the secondary mirror support structure (100) in the main box body (300) respectively and determine the installation position of the secondary mirror support structure (100) in the main box body (300); S3. Remove the secondary frame (120) connected to the secondary mirror frame (110), install the mid-wave infrared mirror box (400) below the main box body (300), and complete the mid-wave infrared optical path passing through with a theodolite; S4. Complete the visible optical path passing through with a theodolite and connect the secondary frame (120) to the secondary mirror frame (110).

7. The method for installing a common-aperture optical system of the secondary mirror support structure according to claim 6, wherein The step S2 specifically includes: S2.

1. Place a plane mirror (310) in front of the main box body (300) and place a laser interferometer (311) behind the main box body (300); S2.

2. Install the main mirror assembly (320) and the secondary mirror support structure (100) in the main box body (300) respectively, install the secondary mirror (130) on the secondary frame (120), make the main mirror assembly (320) close to the rear of the main box body (300), and make the secondary mirror support structure (100) close to the front of the main box body (300); S2.

3. Adjust the laser interferometer (311) and the plane mirror (310) to make the laser interferometer (311) measure the wavefront aberration at the primary image plane; S2.

4. Adjust the installation position and installation angle of the secondary mirror support structure (100) and the main box body (300) to make the wavefront aberration at the primary image plane meet the set index; S2.

5. Determine the installation position of the secondary mirror frame (110) in the main box body (300), and remove the plane mirror (310) and the laser interferometer (311).

8. The method for installing a common-aperture optical system of a secondary mirror support structure according to claim 7, wherein The specific steps for installing the secondary mirror (130) on the secondary frame (120) are as follows: Embed the secondary mirror (130) into the secondary mirror installation hole (121) so that the bottom of the flexible hinge (200) contacts the circumferential side end face of the secondary mirror (130); Use the secondary mirror retaining ring (140) to be embedded into the retaining ring installation groove for limiting the secondary mirror (130); Inject epoxy glue through the epoxy glue injection hole (230) to form a plurality of epoxy glue spots on the circumferential side end face of the secondary mirror (130); After the epoxy glue spots are cured, detect whether the surface shape of the secondary mirror (130) is qualified. If it is unqualified, remove the epoxy glue spots and inject the epoxy glue through the epoxy glue injection hole (230) again; if it is qualified, inject silicone rubber through the silicone rubber injection hole (123) to form a plurality of silicone rubber spots on the circumferential side end face of the secondary mirror (130); After the silicone rubber glue spot is cured, check whether the surface shape of the secondary mirror (130) is qualified. If it is unqualified, remove the silicone rubber glue spot and inject silicone rubber again through the silicone rubber injection hole (123); if it is qualified, connect the light shield (150) to the secondary mirror frame (120).

9. The installation method of the common-aperture optical system of the secondary mirror support structure according to claim 8, characterized in that, The specific steps of step S3 include: S3.

1. Remove the secondary mirror frame (120) connected to the secondary mirror holder (110), and remove the laser interferometer (311) and the plane mirror (310). S3.

2. Install the main mirror crosshair reticle (323) on the back of the main mirror assembly (320), install the first wave infrared Cassegrain mirror assembly (330) on the main box body (300), and place the first theodolite (331) behind the main box body (300) so that the first wave infrared Cassegrain mirror assembly (330) faces the secondary mirror holder (110) and the first theodolite (331) faces the main mirror crosshair reticle (323). S3.

3. Set the mid-wave infrared mirror box (400) below the main box body (300). S3.

4. Install the second mid-wave infrared Cassegrain mirror assembly (410) and the mid-wave infrared lens group support (420) in the mid-wave infrared mirror box (400), set the second theodolite (411) behind the mid-wave infrared mirror box (400), and install the mid-wave infrared lens group crosshair reticle (421) on the mid-wave infrared lens group support (420) so that the second mid-wave infrared Cassegrain mirror assembly (410) faces the first wave infrared Cassegrain mirror assembly (330). S3.

5. Use the first theodolite (331) to aim at the main mirror crosshair reticle (323) so that the reflected image of the crosshair of the main mirror crosshair reticle (323) coincides with the central crosshair of the field of view of the first theodolite (331). S3.

6. By adjusting the height of the mid-wave infrared lens group crosshair reticle (421), make the reflected image of the crosshair of the mid-wave infrared lens group crosshair reticle (421) coincide with the central crosshair of the field of view of the first theodolite (331).

10. The method for installing a common-aperture optical system of the secondary mirror support structure according to claim 9, characterized in that, The specific steps of step S4 include: S4.

1. Remove the mid-wave infrared lens group crosshair reticle (421) and the main mirror crosshair reticle (323). S4.

2. Adjust the second theodolite (411) so that the second theodolite (411) is autocollimated with the first theodolite (331), and remove the first theodolite (331). S4.

3. Install the first visible light Cassegrain mirror assembly (340) in the main box body (300) so that the first visible light Cassegrain mirror assembly (340) faces the back of the main mirror assembly (320). S4.

4. Install the first visible light lens group support (350) and the second visible light lens group support (370) on the top of the main box body (300) so that the first visible light lens group support (350) and the second visible light lens group support (370) are respectively located on the opposite sides of the main mirror assembly (320). S4.

5. Install the first visible light lens group reticle (351) and the second visible light coudé mirror assembly (360) on the first visible light lens group support (350), and install the second visible light lens group reticle (371) on the second visible light lens group bracket (370), so that both the first visible light lens group reticle (351) and the second visible light lens group reticle (371) are opposite to the second visible light coudé mirror assembly (360); S4.

6. Adjust the first visible light lens group support (350) and the second visible light lens group bracket (370) respectively, so that the reflected image of the crosshair of the first visible light lens group reticle (351) and the reflected image of the crosshair of the second visible light lens group reticle (371) both coincide with the crosshair engraved line at the center of the field of view of the second theodolite (411), and determine the installation positions of the first visible light lens group support (350) and the second visible light lens group bracket (370); S4.

7. Determine the installation positions of the secondary frame (120) and the secondary mirror frame (110) by the cooperation of the positioning pin and the connecting positioning hole (127); connect the secondary frame (120) installed with the secondary mirror (130) and the light shield (150) to the secondary mirror frame (110) through the mirror frame connecting hole (126).

Images