High-temperature-adaptability combined optical path turning lens assembly

Abstract

The utility model relates to the technical field of optical lenses, in particular to a high-temperature-adaptability combined optical path turning lens assembly, which comprises an L-shaped lens barrel, a transverse lens group, a reflector group and a longitudinal lens group, the transverse lens group, the reflector group and the longitudinal lens group are located in the L-shaped lens barrel, and the optical axis direction of the transverse lens group and the optical axis direction of the longitudinal lens group are perpendicular and intersect at the reflector group. According to the utility model, 90-degree light path reflex of the lens assembly with the multi-lens structure is realized through the reflector group, and the propagation direction of light rays is changed; and meanwhile, the lens assembly and the reflection assembly mostly adopt flexible design, so that the influence of thermal expansion and cold contraction of the structural member on the lens is reduced, and overlarge stress is avoided.

Description

TECHNICAL FIELD

[0001] The utility model belongs to optical lens technical field, especially relate to a high temperature adaptability combination formula light path foldover lens subassembly. BACKGROUND

[0002] Lens is a kind of commonly used optical element, is widely used in optical instruments and equipment, is made of transparent material, such as glass, plastic and crystal, a kind of optical element, lens subassembly refers to the combination according to certain positional relationship by multiple lenses, the effect of lens subassembly is determined by optical properties and design features, usually can change the propagation direction of light, diverge or converge light, also can change wavefront shape etc., based on the effect of the above lens subassembly, can play different efficacy in optical precision instruments and equipment.

[0003] Lens subassembly as an important optical element, through reasonable design and combination can realize focal length control, field adjustment, chromatic aberration correction and wavefront control etc., for realizing high-quality imaging, accurate measurement and optical signal processing has important significance.

[0004] At present, most lens subassembly in this field is straight cylinder structure, that is, the light path propagation direction is a straight line, does not occur foldover, such as correction mirror, compensator etc., no reference light path foldover type lens subassembly can be found, at the same time, most lens subassembly is fitted and adjusted by the way of secondary processing of centering machine to ensure that its eccentricity, tilt and spacing meet the requirements, resulting in the increase of product processing cycle and cost, and the environment of lens subassembly applied in space remote sensing optics is relatively stable, generally applied in the laboratory with temperature control, or on the space camera with certain thermal control environment, so the influence of temperature change on the performance index of the whole assembly can be ignored when designing the above lens subassembly structure scheme, the optical athermalization design method of lens subassembly developed in recent years aims to eliminate the influence of temperature change on the performance index of the whole machine by considering factors such as lens parameters, support structure thermal deformation and lens surface shape change, but this method only focuses on the whole lens subassembly system, and does not fully consider the interaction between single lens and spacer and lens seat caused by temperature change, that is, when the environmental temperature changes in a certain range, the single lens is affected by the thermal expansion and contraction of the spacer, lens seat and threaded compression ring, which will cause the lens surface shape to change, and this design method does not consider this, therefore, this method also has certain limitations. UTILITY MODEL CONTENTS

[0005] In view of the above, the present utility model aims to provide a high-temperature adaptable combined optical path folding lens assembly, which uses a reflector group to realize a 90° optical path folding of the multi-lens structure lens assembly, changing the direction of light propagation; at the same time, most of the lens assembly and reflector assembly adopt a flexible design, thereby reducing the impact of thermal expansion and contraction of structural components on the lens and avoiding excessive stress.

[0006] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0007] A high-temperature adaptable combined optical path folding lens assembly includes an L-shaped lens barrel, and a lateral lens group, a reflector group, and a longitudinal lens group with flexible structures. The lateral lens group, reflector group, and longitudinal lens group are located within the L-shaped lens barrel, and the optical axis of the lateral lens group is perpendicular to and intersects with the optical axis of the longitudinal lens group at the reflector group. The lateral lens group includes a first lens group, a second lens group, a third lens group, and a fourth lens group; the first lens group is located away from the reflector group, and the fourth lens group is located close to the reflector group. The longitudinal lens group includes a fifth lens group, a sixth lens group, and a seventh lens group; the fifth lens group is located close to the reflector group, and the seventh lens group is located away from the reflector group.

[0008] Furthermore, the L-shaped lens tube includes a transverse lens tube and a longitudinal lens tube; wherein, the longitudinal lens tube is a hollow cylindrical structure, and the longitudinal lens group is installed inside the longitudinal lens tube; the transverse lens tube is an integral structure, including a mirror mounting part and a transverse lens mounting part; the transverse lens mounting part is a hollow cylindrical structure, and the transverse lens group is installed inside the transverse lens mounting part; the mirror mounting part is provided with a first connecting surface, a second connecting surface and a third connecting surface, the transverse lens mounting part is connected to the first connecting surface, the longitudinal lens tube is connected to the second connecting surface, the mirror group is connected to the third connecting surface, and the first connecting surface is perpendicular to the second connecting surface.

[0009] Furthermore, the first lens group includes lenses with a linear expansion coefficient of 21.7 × 10⁻⁶. -6 The first and second lenses are provided at a temperature of / ℃, and a first aluminum alloy lens mount is provided. The first aluminum alloy lens mount is a hollow columnar structure. The outer side of the first aluminum alloy lens mount is tightly connected to the transverse lens mounting part. The inner wall of the first aluminum alloy lens mount is provided with a first lens mounting groove and a first lens mounting stage. The first lens is placed in the first lens mounting groove and is pressed and secured by an aluminum alloy pressure ring. The second lens is placed on the first lens mounting stage, and a spacer is placed between the first lens and the second lens to separate the first lens and the second lens. At least three stress-free adhesive grooves are provided on the side wall of the first aluminum alloy lens mount and located in the first lens mounting groove. The stress-free adhesive grooves are filled with RTV adhesive and are used to fill the first aluminum alloy lens mount with RTV adhesive.

[0010] Furthermore, the second lens group includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The third lens and the first titanium alloy lens mount are at a temperature of / ℃. The first titanium alloy lens mount is an integral structure, including an inner ring, a stage, and an outer ring. The inner ring is coaxially placed inside the outer ring, and the stage connects the inner and outer rings. The outer side of the outer ring is tightly connected to the transverse lens mounting part, and the outer ring is connected to the first aluminum alloy lens mount. A flexible groove along the circumference of the stage is formed on the stage. A second lens mounting groove is provided on the inner wall of the inner ring, and the third lens is placed in the second lens mounting groove and secured by a titanium alloy retaining ring. At least three stress-free adhesive grooves are formed in the second lens mounting groove, and RTV adhesive is filled in the stress-free adhesive grooves. The stress-free adhesive grooves are used to fill the first titanium alloy lens mount with RTV adhesive.

[0011] Furthermore, the third lens group includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The fourth lens and the second titanium alloy lens mount are at a temperature of / ℃. The second titanium alloy lens mount is an integral structure, including an inner ring and a stage. The outer side of the stage is tightly connected to the transverse lens mounting part, and a flexible groove along the circumferential direction of the stage is formed on the stage. The inner ring is placed inside the stage, and a third lens mounting groove is provided on the inner wall of the inner ring. The fourth lens is placed in the third lens mounting groove and secured by a titanium alloy retaining ring. At least three stress-free adhesive grooves are formed in the third lens mounting groove. The stress-free adhesive grooves are filled with RTV adhesive and are used to fill the second titanium alloy lens mount with RTV adhesive.

[0012] Furthermore, the fourth lens group includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The fifth lens and the third titanium alloy lens mount are at a temperature of / ℃. The third titanium alloy lens mount is an integral structure, including an inner ring and a stage. A spacer is provided between the third lens mount stage and the second titanium alloy lens mount, and the outer side of the third lens mount stage is in close contact with the transverse lens mounting part. A flexible groove along the circumference of the third lens mount stage is provided on the third lens mount stage. The inner ring of the third lens mount is placed inside the third lens mount stage, and a fourth lens mounting groove is provided on the inner wall of the inner ring of the third lens mount. The fifth lens is placed in the fourth lens mounting groove and is pressed and secured by a titanium alloy pressure ring.

[0013] Furthermore, the reflector assembly includes a 45° reflector, a flexible backplate, adjustment shims, and a rear backplate; wherein, the flexible backplate includes a reflector mounting platform and flexible joints; the 45° reflector is bonded to the reflector mounting platform with epoxy adhesive; there are no fewer than two flexible joints and they are flexibly connected to the reflector mounting platform; all flexible joints are mounted on the rear backplate with screws; the rear backplate is connected to the third connection surface through adjustment shims.

[0014] Furthermore, the fifth lens group includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The sixth lens and the fourth titanium alloy lens mount are at a temperature of / ℃. The fourth titanium alloy lens mount is a hollow cylindrical structure. The outer side of the fourth titanium alloy lens mount is in close contact with the longitudinal lens tube. A fifth lens mounting groove is provided on the inner wall of the fourth titanium alloy lens mount, and the sixth lens is placed in the fifth lens mounting groove. At least three stress-free adhesive grooves are opened in the fifth lens mounting groove. The stress-free adhesive grooves are filled with RTV adhesive and are used to fill the fourth titanium alloy lens mount with RTV adhesive.

[0015] Furthermore, the sixth lens group includes lenses with a linear expansion coefficient of 21.7 × 10⁻⁶. -6 The seventh and eighth lenses at / ℃, and the second aluminum alloy lens mount; wherein, the second aluminum alloy lens mount is a hollow columnar structure, the bottom of the second aluminum alloy lens mount is connected to the fourth titanium alloy lens mount, and the outer side of the second aluminum alloy lens mount is tightly connected to the longitudinal lens tube; the inner wall of the second aluminum alloy lens mount is provided with a sixth lens mounting groove and a second lens mounting stage; the seventh lens is placed on the second lens mounting stage; the eighth lens is placed in the sixth lens mounting groove and is pressed and secured by an aluminum alloy pressure ring, and a spacer is placed between the seventh and eighth lenses to separate the seventh and eighth lenses; on the side wall of the second aluminum alloy lens mount, at least 3 stress-free glue grooves are opened in the sixth lens mounting groove, and the stress-free glue grooves are filled with RTV glue, the stress-free glue grooves are used to fill the second aluminum alloy lens mount with RTV glue.

[0016] Furthermore, the seventh lens group includes lenses with a linear expansion coefficient of 21.7 × 10⁻⁶. -6 The ninth lens at / ℃, and the third aluminum alloy lens mount; wherein, the third aluminum alloy lens mount is a hollow columnar structure, the outer side of the third aluminum alloy lens mount is in close contact with the longitudinal lens tube, and the bottom of the third aluminum alloy lens mount is connected to the second aluminum alloy lens mount; a seventh lens mounting groove is provided on the inner wall of the third aluminum alloy lens mount, and the ninth lens is placed in the seventh lens mounting groove.

[0017] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0018] (1) The high temperature adaptable combined optical path folding lens assembly of this utility model aims to achieve optical path folding. The optical path is folded by the reflector group, which further changes the propagation direction of the optical path. At the same time, most of the lens group and the reflector group adopt a flexible structure design to reduce the influence of thermal expansion and contraction of structural components on the lens and avoid excessive stress.

[0019] (2) The high temperature adaptable combined optical path folding lens assembly of this utility model has a stress-free glue groove designed inside the flexible lens mount. By applying RTV glue to bond the lens and the flexible lens mount together, the lens assembly can improve its ability to resist thermal and vibration environments.

[0020] (3) The high temperature adaptable combined optical path folding lens assembly of this utility model determines the material of the corresponding lens mount according to the linear expansion coefficient of different lenses, and strives to match the lens and lens mount from the perspective of linear expansion coefficient to improve the temperature adaptability of the lens assembly. Attached Figure Description

[0021] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0022] Figure 1 This is a cross-sectional view of the high-temperature adaptable combined optical path folding lens assembly described in this embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the external structure of the high-temperature adaptable combined optical path folding lens assembly described in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the optical path of the high-temperature adaptable combined optical path folding lens assembly described in this embodiment of the present invention;

[0025] Figure 4 This is a bottom view of the horizontal lens tube structure described in an embodiment of the present invention;

[0026] Figure 5 This is a cross-sectional view of the first aluminum alloy mirror mount according to an embodiment of the present invention;

[0027] Figure 6 This is a cross-sectional view of the first titanium alloy mirror mount according to an embodiment of the present invention;

[0028] Figure 7 This is a cross-sectional view of the second titanium alloy mirror mount according to an embodiment of the present invention;

[0029] Figure 8This is a cross-sectional view of the third titanium alloy mirror mount according to an embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram of the structure of the flexible backplate described in an embodiment of the present invention;

[0031] Figure 10 This is a cross-sectional view of the fourth titanium alloy mirror mount according to an embodiment of the present invention;

[0032] Figure 11 This is a cross-sectional view of the second aluminum alloy mirror mount according to an embodiment of the present invention;

[0033] Figure 12 This is a cross-sectional view of the third aluminum alloy mirror mount according to an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. L-shaped lens barrel; 11. Horizontal lens barrel; 111. Horizontal lens mounting part; 112. Reflector mounting part; 12. Vertical lens barrel; 2. Horizontal lens group;

[0036] 21. First lens group; 211. First lens; 212. Second lens; 213. First aluminum alloy lens mount; 214. First lens mounting slot; 215. First lens mounting stage;

[0037] 22. Second lens group; 221. Third lens; 222. First titanium alloy lens mount; 223. Inner ring of the first lens mount; 224. First lens mount stage; 225. Outer ring of the first lens mount; 226. Second lens mounting slot;

[0038] 23. Third lens group; 231. Fourth lens; 232. Second titanium alloy lens mount; 233. Inner ring of the second lens mount; 234. Second lens mount stage; 235. Third lens mounting slot;

[0039] 24. Fourth lens group; 241. Fifth lens; 242. Third titanium alloy lens mount; 243. Inner ring of the third lens mount; 244. Third lens mount stage; 245. Fourth lens mounting slot; 3. Reflector group;

[0040] 31. 45° reflector; 32. Flexible backplate; 321. Reflector mounting platform; 322. Flexible joint; 33. Adjustment shim; 34. Rear backplate; 4. Longitudinal lens group;

[0041] 41. Fifth lens group; 411. Sixth lens; 412. Fourth titanium alloy lens mount; 413. Fifth lens mounting slot;

[0042] 42. Sixth lens group; 421. Seventh lens; 422. Eighth lens; Second aluminum alloy lens mount 423; 424. Sixth lens mounting slot; 425. Second lens mounting stage;

[0043] 43. Seventh lens group; 431. Ninth lens; 432. Third aluminum alloy lens mount; 433. Seventh lens mounting slot; 5. Aluminum alloy pressure ring; 6. Spacer; 7. Stress-free adhesive groove; 8. Flexible groove; 9. Titanium alloy pressure ring. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and do not constitute a limitation thereof.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0046] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0047] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0048] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0049] likeFigures 1 to 3 As shown, the high-temperature adaptable combined optical path folding lens assembly described in this embodiment of the present invention includes an L-shaped lens tube 1, and a transverse lens group 2, a reflector group 3, and a longitudinal lens group 4 with flexible structures.

[0050] The L-shaped lens tube includes a horizontal lens tube 11 and a vertical lens tube 12. The horizontal lens tube 11 is an integral structure, as shown in the figure. Figure 4 The system includes a lateral lens mounting section 111 and a reflector mounting section 112. The lateral lens mounting section 111 is a hollow cylindrical structure, and the lateral lens group 2 is mounted inside it. The reflector mounting section 112 has a first connecting surface, a second connecting surface, and a third connecting surface, with the first connecting surface perpendicular to the second connecting surface. The lateral lens mounting section 111 is connected to the first connecting surface. The longitudinal lens tube 12 is a hollow cylindrical structure, and the longitudinal lens group 4 is mounted inside it. The longitudinal lens tube 12 is connected to the second connecting surface via four M3x8 screws. The reflector group 3 is connected to the third connecting surface. At this point, the optical axis of the lateral lens group 2 is perpendicular to and intersects with the optical axis of the longitudinal lens group 4 at the reflector group 3, thereby causing the reflector group 3 to refract the light rays from the lateral lens group 2 and the longitudinal lens group 4 by 90°.

[0051] Furthermore, the lateral lens group 2 includes a first lens group 21, a second lens group 22, a third lens group 23, and a fourth lens group 24, with the first lens group 21 being farther away from the mirror group 3 and the fourth lens group 24 being closer to the mirror group 3.

[0052] The first lens group 21 includes lenses with a linear expansion coefficient of 21.7 × 10⁻⁶. -6 The first lens 211 and the second lens 212, and the first aluminum alloy lens mount 213, are located at a temperature of / ℃. Figure 1 and Figure 5 As shown, the first aluminum alloy lens mount 213 is a hollow columnar structure. The outer side of the first aluminum alloy lens mount 213 is tightly connected to the transverse lens mounting part 111 of the transverse lens tube 11. The inner wall of the first aluminum alloy lens mount 213 is provided with a first lens mounting groove 214 and a first lens mounting stage 215. The first lens 211 is placed in the first lens mounting groove 214 and is pressed and secured by an aluminum alloy pressure ring 5. The second lens 212 is placed on the first lens mounting stage 215, and a spacer 6 is placed between the first lens 211 and the second lens 212 to separate the first lens 211 and the second lens 212. On the side wall of the first aluminum alloy lens mount 213, and located in the first lens mounting groove 214, there are no fewer than three stress-free adhesive grooves 7. RTV adhesive (vulcanized silicone rubber) for fixing the second lens 212 is injected into the stress-free adhesive grooves 7 on the outer radial side of the first aluminum alloy lens mount 213.

[0053] The second lens group 22 includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The third lens 221 and the first titanium alloy mount 222 are at a temperature of / ℃. For example... Figure 1 and Figure 6 As shown, the first titanium alloy lens mount 222 is an integral structure, including a first inner lens mount ring 223, a first lens mount stage 224, and a first outer lens mount ring 225. The first inner lens mount ring 223 is coaxially placed inside the first outer lens mount ring 225, and the first lens mount stage 224 connects the first inner lens mount ring 223 and the first outer lens mount ring 225. The outer side of the first outer lens mount ring 225 is in close contact with the transverse lens mounting portion 111 of the transverse lens tube 11, and the first outer lens mount ring 225 is in contact with the first aluminum alloy lens mount 213. A flexible groove 8 is formed on the first lens mount stage 224 along the circumferential direction of the first lens mount stage 224. A second lens mounting groove 226 is provided on the inner wall of the first inner lens mount ring 223, and a third lens 221 is placed in the second lens mounting groove 226 and pressed into place by a titanium alloy retaining ring 9. No fewer than three stress-free adhesive grooves 7 are provided in the second lens mounting groove 226, and RTV adhesive for fixing the third lens 221 is injected into the stress-free adhesive grooves 7 on the outer radial side of the first titanium alloy lens mount 222.

[0054] The third lens group 23 includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The fourth lens 231 and the second titanium alloy mount 232 at / ℃. For example... Figure 1 and Figure 7 As shown, the second titanium alloy lens mount 232 is an integral structure, including a second lens mount inner ring 233 and a second lens mount stage 234. The outer side of the second lens mount stage 234 is tightly connected to the transverse lens mounting portion 111 of the transverse lens tube 11, and a flexible groove 8 along the circumferential direction of the second lens mount stage 234 is formed on the second lens mount stage 234. The second lens mount inner ring 233 is placed inside the second lens mount stage 234, and a third lens mounting groove 235 is provided on the inner wall of the second lens mount inner ring 233. The fourth lens 231 is placed in the third lens mounting groove 235 and is pressed and secured by a titanium alloy pressure ring 9. At least three stress-free adhesive grooves 7 are formed in the third lens mounting groove 235, and RTV adhesive for fixing the fourth lens 231 is injected into the stress-free adhesive grooves 7 on the outer radial side of the second titanium alloy lens mount 232.

[0055] The fourth lens group 24 includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The fifth lens 241 and the third titanium alloy mount 242 are at / ℃. For example... Figure 1 and Figure 8As shown, the third titanium alloy lens mount 242 is an integral structure, including a third lens mount inner ring 243 and a third lens mount stage 244. A spacer 6 is provided between the third lens mount stage 244 and the second titanium alloy lens mount 232, and the outer side of the third lens mount stage 244 is in close contact with the transverse lens mounting part 111 of the transverse lens tube 11. A flexible groove 8 is formed on the third lens mount stage 244 along the circumferential direction of the third lens mount stage 244. The third lens mount inner ring 243 is placed inside the third lens mount stage 244, and a fourth lens mounting groove 245 is provided on the inner wall of the third lens mount inner ring 243. The fifth lens 241 is placed in the fourth lens mounting groove 245 and is pressed and secured by a titanium alloy pressure ring 9.

[0056] The mirror assembly 3 includes a 45° mirror 31, a flexible backplate 32, an adjustment shim 33, and a rear backplate 34. The flexible backplate 32 has the following structure: Figure 1 and Figure 9 As shown, the system includes a mirror mounting platform 321 and flexible joints 322. A 45° mirror 31 is bonded to the mirror mounting platform 321 with epoxy adhesive. There are at least two flexible joints 322, which are flexibly connected to the mirror mounting platform 321. All flexible joints 322 are mounted on the back plate 34 with screws. The back plate 34 is connected to the third connecting surface of the mirror mounting part 112 through adjusting shims 33.

[0057] Specifically, in this embodiment of the invention, there are two flexible joints 322. Each flexible joint 322 is mounted on the back plate 34 using two M3x8 screws. That is, the flexible back plate 32 is mounted on the back plate 34 using four M3x8 screws. Then, four M3x14 screws are used to connect the back plate 34, the adjustment shim 33, and the flexible back plate 32 through and onto the third connecting surface of the reflector mounting part 112. When it is necessary to adjust the spatial position and angle of the 45° reflector 31, only the adjustment shim 10 needs to be processed or ground accordingly. The flexible back plate 32 is an integral structure, and the 45° reflector 31 is preferably bonded to the reflector mounting platform 321 using a two-component epoxy adhesive. The flexible back plate 32 provided in this embodiment of the invention can effectively reduce the impact of temperature changes and vibration on the 45° reflector 31.

[0058] The longitudinal lens group 4 includes a fifth lens group 41, a sixth lens group 42, and a seventh lens group 43. The fifth lens group 41 is closer to the mirror group 3, and the seventh lens group is farther away from the mirror group 43.

[0059] The fifth lens group 41 includes lenses with a linear expansion coefficient of 7.8 × 10⁻⁶. -6 The sixth lens 411 and the fourth titanium alloy lens mount 412 are located at / ℃. The structure of the fourth titanium alloy lens mount 412 is as follows: Figure 1 and Figure 10As shown, the fourth titanium alloy lens mount 412 is a hollow columnar structure. The outer side of the fourth titanium alloy lens mount 412 is in close contact with the longitudinal lens tube 12, and a fifth lens mounting groove 413 is provided on the inner wall of the fourth titanium alloy lens mount 412. The sixth lens 411 is placed in the fifth lens mounting groove. At least three stress-free adhesive grooves 7 are opened in the fifth lens mounting groove. RTV adhesive for fixing the sixth lens 411 is injected into the stress-free adhesive grooves 7 on the outer radial side of the fourth titanium alloy lens mount 412.

[0060] The sixth lens group 42 includes lenses with a linear expansion coefficient of 21.7 × 10⁻⁶. -6 The seventh lens 421 and the eighth lens 422 are at a temperature of / ℃, and the second aluminum alloy lens mount 423 is also present. The structure of the second aluminum alloy lens mount 423 is as follows: Figure 1 and Figure 11 As shown, the second aluminum alloy lens mount 423 is a hollow columnar structure. The bottom of the second aluminum alloy lens mount 423 is connected to the fourth titanium alloy lens mount 412, and the outer side of the second aluminum alloy lens mount 423 is tightly connected to the longitudinal lens tube 12. The inner wall of the second aluminum alloy lens mount 423 is provided with a sixth lens mounting groove 424 and a second lens mounting stage 425. The seventh lens 421 is placed on the second lens mounting stage 425; the eighth lens 422 is placed in the sixth lens mounting groove 424 and is pressed and secured by an aluminum alloy pressure ring 5. A spacer 6 is placed between the seventh lens 421 and the eighth lens 422 to separate them. On the side wall of the second aluminum alloy lens mount 423, at least three stress-free adhesive grooves 7 are opened in the sixth lens mounting groove 424. RTV adhesive for fixing the eighth lens 422 is injected into the stress-free adhesive grooves 7 on the outer radial side of the second aluminum alloy lens mount 423.

[0061] The seventh lens group 43 includes lenses with a linear expansion coefficient of 21.7 × 10⁻⁶. -6 The ninth lens 431 at / ℃, and the third aluminum alloy lens mount 432. The structure of the third aluminum alloy lens mount 432 is as follows: Figure 1 and Figure 12 As shown, the third aluminum alloy lens mount 432 is a hollow columnar structure. The outer side of the third aluminum alloy lens mount 432 is in close contact with the longitudinal lens tube 12, and the bottom of the third aluminum alloy lens mount 432 is connected to the second aluminum alloy lens mount 423. A seventh lens mounting groove 433 is provided on the inner wall of the third aluminum alloy lens mount 432, and the ninth lens 431 is placed in the seventh lens mounting groove 433.

[0062] In the embodiments of this utility model, each lens mount has four stress-free adhesive grooves 7, evenly distributed along the lens mount. Both the aluminum alloy retaining ring 5 and the titanium alloy retaining ring 9 are threaded retaining rings, meaning that the aluminum alloy retaining ring 5 and the titanium alloy retaining ring 9 secure the corresponding lens to the corresponding lens mount via threads. To ensure a heat-free optical design, the lens assembly structure provided in this utility model embodiment is preferably made of 6061 aluminum alloy. Furthermore, the linear expansion coefficients of the third lens 221, fourth lens 231, fifth lens 241, and sixth lens 411 preferably used in this utility model embodiment are all 7.8 × 10⁻⁶. -6 / ℃, these lenses have a small coefficient of linear expansion, and compared to the coefficient of linear expansion of titanium alloy (8.6×10). -6 Since the coefficients of thermal expansion (°C) are similar, the mounts for the third lens 221, fourth lens 231, fifth lens 241, and sixth lens 411 are all made of titanium alloy. Furthermore, to match the linear expansion coefficients of the flexible backplate 32 and the 45° reflecting mirror 31, the material of the flexible backplate 32 is preferably Invar. After determining the materials for the above components, the remaining materials for the high-temperature adaptable combined optical path folding lens assembly described in this embodiment are all aluminum alloy. The selection of these materials improves the temperature adaptability of the lens assembly. Simultaneously, in this embodiment, stress-free adhesive grooves 7 for filling RTV adhesive are provided in the corresponding mounts, and the corresponding mounts are fixed using RTV adhesive, thereby ensuring that no radial stress is generated between the mount and the outer diameter of the corresponding lens when the temperature environment of the lens assembly changes.

[0063] Specifically, the assembly and adjustment process of the high-temperature adaptable combined optical path folding lens assembly described in this embodiment of the invention is as follows:

[0064] First, after installing the transverse lens group 2 in the transverse lens mounting part 111 of the transverse lens tube 11 and the longitudinal lens group 4 in the longitudinal lens tube 12 according to the above connection relationship, the longitudinal lens tube 12 is connected to the second connecting surface of the reflector mounting part 112 using four M3x8 screws, thus completing the installation and positioning of the transverse lens group 2 and the longitudinal lens group 4.

[0065] Next, the 45° reflector 31 is bonded to the reflector mounting platform 321 with two-component epoxy adhesive, and each flexible joint 322 is mounted on the back panel 34 with two M3x8 screws. This completes the mounting of the 45° reflector 31 onto the back panel 34 via the flexible back panel 32.

[0066] Then, the position of the 45° reflector 31 is determined by optical testing to ensure that the optical axis of the transverse lens group 2 is perpendicular to the optical axis of the longitudinal lens group 4 and intersects on the surface of the 45° reflector 31. Then, the adjustment shim 33 is adjusted and processed according to the position of the 45° reflector 31. Finally, four M3x14 screws are used to install the adjustment shim 33 and the back plate 34 on the third connecting surface of the reflector mounting part 112.

[0067] Finally, aluminum alloy retaining rings 5 ​​are used to press the first aluminum alloy lens mount 213 and the third aluminum alloy lens mount 432 into the transverse lens barrel 11 and the longitudinal lens barrel 12, respectively. This completes the assembly and adjustment of the high-temperature adaptable combined optical path folding lens assembly described in this embodiment of the invention.

[0068] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A high temperature adaptive combined light path folding lens assembly, characterized by: The L-shaped lens barrel and the transverse lens group, the mirror group and the longitudinal lens group with flexible structure; wherein the transverse lens group, the mirror group and the longitudinal lens group are located in the L-shaped lens barrel, and the optical axis direction of the transverse lens group and the optical axis direction of the longitudinal lens group are perpendicular and intersect at the mirror group; wherein the transverse lens group comprises a first lens group, a second lens group, a third lens group and a fourth lens group; the first lens group is away from the mirror group, and the fourth lens group is close to the mirror group; the longitudinal lens group comprises a fifth lens group, a sixth lens group and a seventh lens group, the fifth lens group is close to the mirror group, and the seventh lens group is away from the mirror group.

2. The high temperature tolerant combined light path folding lens assembly of claim 1, wherein: The L-shaped lens barrel comprises a transverse lens barrel and a longitudinal lens barrel; wherein the longitudinal lens barrel is a hollow columnar structure, and the longitudinal lens group is installed inside the longitudinal lens barrel; the transverse lens barrel is an integral structure, comprising a mirror mounting part and a transverse lens mounting part; the transverse lens mounting part is a hollow columnar structure, and the transverse lens group is installed inside the transverse lens mounting part; the mirror mounting part is provided with a first connecting surface, a second connecting surface and a third connecting surface, the transverse lens mounting part is connected with the first connecting surface, the longitudinal lens barrel is connected with the second connecting surface, the mirror group is connected with the third connecting surface, and the first connecting surface is perpendicular to the second connecting surface.

3. The high temperature tolerant combined light path folding lens assembly of claim 2, wherein: The first lens group comprises a first lens and a second lens with a linear expansion coefficient of 21.7*10 -6 / ℃, and a first aluminum alloy mirror seat; wherein the first aluminum alloy mirror seat is a hollow columnar structure, the outer side of the first aluminum alloy mirror seat is tightly matched with the transverse lens mounting part, the inner wall of the first aluminum alloy mirror seat is provided with a first lens mounting groove and a first lens mounting table; the first lens is placed in the first lens mounting groove and is fixed by an aluminum alloy pressing ring; the second lens is placed on the first lens mounting table, and a spacer ring for spacing the first lens and the second lens is placed between the first lens and the second lens; on the side wall of the first aluminum alloy mirror seat and in the first lens mounting groove, not less than three stress-free glue grooves are opened, which are used to fill RTV glue into the first aluminum alloy mirror seat.

4. The high temperature tolerant combined light path folding lens assembly of claim 3, wherein: The second lens group comprises a third lens with a linear expansion coefficient of 7.8*10 -6 / ℃ and a first titanium alloy lens seat; wherein the first titanium alloy lens seat is an integral structure, comprising a first lens seat inner ring, a first lens seat table and a first lens seat outer ring; wherein the first lens seat inner ring is coaxially arranged inside the first lens seat outer ring, and the first lens seat table connects between the first lens seat inner ring and the first lens seat outer ring; the outer side of the first lens seat outer ring is closely connected with the transverse lens mounting part, and the first lens seat outer ring is connected with a first aluminum alloy lens seat; a flexible groove along the circumferential direction of the first lens seat table is formed on the first lens seat table; the inner wall of the first lens seat inner ring is provided with a second lens mounting groove, the third lens is placed in the second lens mounting groove and is pressed and fixed by a titanium alloy pressing ring; not less than three stress-free glue grooves are formed in the second lens mounting groove, and the stress-free glue grooves are used to fill RTV glue into the first titanium alloy lens seat.

5. The high temperature tolerant combined light path folding lens assembly of claim 4, wherein: The third lens group comprises a fourth lens with a linear expansion coefficient of 7.8*10 -6 / ℃ and a second titanium alloy mirror seat; wherein the second titanium alloy mirror seat is an integral structure, comprising a second mirror seat inner ring and a second mirror seat base; the outer side of the second mirror seat base is closely connected with the transverse lens mounting part, and a flexible groove along the circumferential direction of the second mirror seat base is formed on the second mirror seat base; the second mirror seat inner ring is placed inside the second mirror seat base, and a third lens mounting groove is arranged on the inner wall of the second mirror seat inner ring; the fourth lens is placed in the third lens mounting groove and is pressed and fixed by a titanium alloy pressing ring; not less than three stress-free glue grooves are formed in the third lens mounting groove; the stress-free glue grooves are used to fill RTV glue into the second titanium alloy mirror seat.

6. The high temperature tolerant combined light path folding lens assembly of claim 5, wherein: The fourth lens group comprises a fifth lens with a linear expansion coefficient of 7.8*10 -6 / ℃ and a third titanium alloy lens seat; wherein the third titanium alloy lens seat is an integral structure, comprising a third lens seat inner ring and a third lens seat base; a spacer ring is arranged between the third lens seat base and the second titanium alloy lens seat, and the outer side of the third lens seat base is closely connected with the transverse lens mounting portion; a flexible groove along the circumferential direction of the third lens seat base is formed on the third lens seat base; the third lens seat inner ring is arranged inside the third lens seat base, and a fourth lens mounting groove is arranged on the inner wall of the third lens seat inner ring; the fifth lens is arranged in the fourth lens mounting groove and is pressed and fixed by a titanium alloy pressing ring.

7. The high temperature tolerant combined light path folding lens assembly of claim 6, wherein: The mirror group comprises a 45° mirror, a flexible back plate, an adjustment gasket and a rear back plate; wherein the flexible back plate comprises a mirror mounting table and a flexible joint; the 45° mirror is bonded with the mirror mounting table through epoxy glue; the number of the flexible joint is not less than two and is flexibly connected with the mirror mounting table; all the flexible joints are installed on the rear back plate through screws; the rear back plate is connected with the third connecting surface through the adjustment gasket.

8. The high temperature tolerant combined light path folding lens assembly of claim 2, wherein: The fifth lens group includes a sixth lens with a linear expansion coefficient of 7.8*10 -6 / ℃ and a fourth titanium alloy lens seat; wherein the fourth titanium alloy lens seat is a hollow columnar structure, the outer side of the fourth titanium alloy lens seat is in close contact with the longitudinal lens barrel, a fifth lens mounting groove is arranged on the inner wall of the fourth titanium alloy lens seat, and the sixth lens is placed in the fifth lens mounting groove; not less than three stress-free glue grooves are opened in the fifth lens mounting groove; and the stress-free glue grooves are filled with RTV glue, and the stress-free glue grooves are used to fill the fourth titanium alloy lens seat with RTV glue.

9. The high temperature tolerant combined light path folding lens assembly of claim 8, wherein: The sixth lens group comprises a seventh lens and an eighth lens with a linear expansion coefficient of 21.7*10 -6 / ℃, and a second aluminum alloy mirror seat; wherein the second aluminum alloy mirror seat is a hollow columnar structure, the bottom of the second aluminum alloy mirror seat is connected with the fourth titanium alloy mirror seat, and the outer side of the second aluminum alloy mirror seat is closely connected with the longitudinal lens barrel; the inner wall of the second aluminum alloy mirror seat is provided with a sixth lens mounting groove and a second lens mounting table; the seventh lens is placed on the second lens mounting table; the eighth lens is placed in the sixth lens mounting groove and is pressed by an aluminum alloy pressing ring, and a spacer ring for spacing the seventh lens and the eighth lens is placed between the seventh lens and the eighth lens; on the side wall of the second aluminum alloy mirror seat, not less than three stress-free glue grooves are opened in the sixth lens mounting groove, and the stress-free glue grooves are filled with RTV glue, and the stress-free glue grooves are used for filling RTV glue into the second aluminum alloy mirror seat.

10. The high temperature tolerant combined light path folding lens assembly of claim 9, wherein: The seventh lens group comprises a ninth lens with a linear expansion coefficient of 21.7*10 -6 / ℃, and a third aluminum alloy lens seat; wherein the third aluminum alloy lens seat is a hollow columnar structure, the outer side of the third aluminum alloy lens seat is in close contact with the longitudinal lens barrel, and the bottom of the third aluminum alloy lens seat is connected with the second aluminum alloy lens seat; a seventh lens mounting groove is arranged on the inner wall of the third aluminum alloy lens seat, and the ninth lens is placed in the seventh lens mounting groove.

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