Non-driven adaptive lens based on double-ring support

Abstract

The invention discloses a non-driven adaptive lens based on double-ring support, and relates to the technical field of optical lenses, the non-driven adaptive lens comprises an outer lens cone, an inner lens cone, a lens group and an elastic member, one end of the outer lens cone is provided with an outer support ring; the inner lens cone is inserted into the outer lens cone, and an inner supporting ring is arranged at the end, facing the outer supporting ring, of the inner lens cone. The lens group is arranged in the inner lens cone and abuts against the inner supporting ring; the elastic piece is arranged between the outer supporting ring and the inner supporting ring and is in a compressed state; the material thermal expansion coefficient of the outer supporting ring is larger than that of the inner supporting ring. According to the non-driven adaptive lens based on the double-ring support, high imaging reliability can be kept in an extreme environment.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and particularly relates to a drive-free adaptive lens based on a double-ring support. Background Art

[0002] The existing optical lenses have insufficient thermal stability. In an environment with large temperature changes, for example, a temperature fluctuation from -20°C to 60°C can cause the displacement of the lens group to reach ±0.1 mm. Some lenses are provided with voice coil motors or piezoelectric ceramics to drive the movement and adjustment of the lens group to overcome the displacement of the lens group caused by temperature changes. Whether it is a voice coil motor solution or a piezoelectric ceramic drive solution, it is extremely easy to fail in extreme environments with high radiation and strong electromagnetic interference. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, the present invention provides a drive-free adaptive lens based on a double-ring support, which can maintain high imaging reliability in extreme environments.

[0004] The drive-free adaptive lens based on a double-ring support according to an embodiment of the present invention includes an outer lens barrel, and an outer support ring is provided at one end of the outer lens barrel; An inner lens barrel is inserted into the outer lens barrel, and an inner support ring is provided at one end of the inner lens barrel facing the outer support ring; A lens group is arranged on the inner lens barrel, and the lens group abuts against the inner support ring; An elastic member is arranged between the outer support ring and the inner support ring, and the elastic member is in a compressed state; Wherein, the thermal expansion coefficient of the material of the outer support ring is greater than the thermal expansion coefficient of the material of the inner support ring.

[0005] The drive-free adaptive lens based on a double-ring support according to an embodiment of the present invention has at least the following beneficial effects: there is an elastic member between the inner support ring and the outer support ring, and there is a floating space. During the process of the environmental temperature rising, the lens group expands due to heat and has a stress in the direction of the outer support ring; the inner support ring and the outer support ring expand synchronously due to heat. Since the thermal expansion coefficient of the material of the outer support ring is greater than the thermal expansion coefficient of the material of the inner support ring, the deformation amount of the outer support ring is greater than the deformation amount of the inner support ring. At the same time, the relative positions of the outer lens barrel and the inner lens barrel are fixed, and the outer support ring deforms towards the inner support ring to further compress the elastic member. The stress is transmitted to the inner support ring and the lens group through the elastic member. The stress applied by the outer support ring to the lens group is opposite to the stress generated by the heat expansion of the lens group, which has the effect of suppressing the expansion and movement of the lens group; the above structure can also adaptively adjust the lens group in extreme environments with high radiation and strong electromagnetic interference, and maintain high imaging reliability in extreme environments.

[0006] According to some embodiments of the present invention, a ring-shaped limiting platform is provided at one end of the endoscope barrel away from the inner support ring. The inner support ring is detachably connected to the endoscope barrel. One end of the lens group abuts against the limiting platform, and the other end of the lens group abuts against the inner support ring.

[0007] According to some embodiments of the present invention, a connecting thread is provided between the inner support ring and the endoscope barrel.

[0008] According to some embodiments of the present invention, the lens group includes a plurality of coaxially arranged lenses. The endoscope barrel is inserted with a plurality of positioning rings. The positioning rings are located between two adjacent lenses, and the lenses abut against the positioning rings.

[0009] According to some embodiments of the present invention, at least three supporting portions are provided on the end face of the positioning ring. The plurality of supporting portions are evenly distributed circumferentially around the positioning ring. Along the axial direction of the positioning ring, the surface of the supporting portion protrudes outward from the end face of the positioning ring.

[0010] According to some embodiments of the present invention, the gap between the lens and the positioning ring is filled with liquid metal, and the gap between the lens and the limiting platform is also filled with liquid metal. The liquid metal is in a solid state within the range of the first temperature threshold and in a liquid state within the range of the second temperature threshold. Among them, the lens operates within the range of the first temperature threshold.

[0011] According to some embodiments of the present invention, a plurality of through holes are provided on the barrel walls of the outer endoscope barrel and the inner endoscope barrel, and the plurality of through holes form a honeycomb lattice structure.

[0012] According to some embodiments of the present invention, a retaining ring is provided at one end of the outer endoscope barrel away from the outer support ring. The retaining ring is detachably connected to the outer endoscope barrel, and the retaining ring abuts against the end of the inner endoscope barrel.

[0013] According to some embodiments of the present invention, a connecting thread is provided between the retaining ring and the outer endoscope barrel.

[0014] According to some embodiments of the present invention, the elastic member is an annular corrugated spring.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0016] The following further describes the present invention with reference to the drawings and embodiments, where: Figure 1Schematic cross-sectional structure diagram of a driverless adaptive lens based on a double-ring support according to an embodiment of the present invention; Figure 2 Schematic enlarged partial structure diagram of a driverless adaptive lens based on a double-ring support according to an embodiment of the present invention; Figure 3 Schematic structure diagram of a positioning ring according to an embodiment of the present invention; Figure 4 Schematic structure diagram of the unfolded barrel wall of an outer lens barrel according to an embodiment of the present invention; Figure 5 Schematic structure diagram of an elastic member according to an embodiment of the present invention.

[0017] Reference numerals in the drawings: Outer lens barrel 100, outer support ring 110, retaining ring 120, inner lens barrel 200, inner support ring 210, limiting platform 220, lens group 300, lens 310, elastic member 400, positioning ring 500, support portion 510. Detailed implementation manners

[0018] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0019] In the description of the present invention, it should be understood that the orientation descriptions such as up and down refer to the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0020] In the description of the present invention, "a plurality of" means more than two. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0021] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", and "connected" should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0022] In an optical lens, a lens group includes a plurality of lenses. The lenses are arranged in a designed order, and the interval between adjacent lenses also needs to be controlled within a designed numerical range. At the same time, the position of the entire lens group in the lens barrel is also relatively fixed to obtain the best imaging effect.

[0023] As described in the background art, in an environment with large temperature variations, the displacement of the lens group will cause the imaging effect of the lens to deteriorate. Although the lens group can be actively driven to move for adjustment, in extreme environments, active driving will become unreliable. For example, in environments with high radiation and strong electromagnetic interference, the control of active driving will be affected and the expected adjustment cannot be performed.

[0024] Refer to Figure 1 As shown, a drive-free adaptive lens based on a double-ring support according to an embodiment of the present invention includes an outer lens barrel 100, an inner lens barrel 200, a lens group 300, and an elastic member 400.

[0025] One end of the outer lens barrel 100 is provided with an outer support ring 110; the inner lens barrel 200 is inserted into the outer lens barrel 100, and one end of the inner lens barrel 200 facing the outer support ring 110 is provided with an inner support ring 210; the lens group 300 is disposed in the inner lens barrel 200, and the lens group 300 abuts against the inner support ring 210; the elastic member 400 is disposed between the outer support ring 110 and the inner support ring 210, and the elastic member 400 is in a compressed state; wherein, the thermal expansion coefficient of the material of the outer support ring 110 is greater than the thermal expansion coefficient of the material of the inner support ring 210.

[0026] An elastic member 400 is provided between the inner support ring 210 and the outer support ring 110. The elastic member 400 can be deformed by force and there is a floating space. During the process of increasing ambient temperature, the lens group 300 expands due to heat and will move towards the floating space to release stress, that is, the lens group 300 has a stress in the direction towards the outer support ring 110.

[0027] When the ambient temperature rises, the inner support ring 210 and the outer support ring 110 are heated and expand synchronously. Since the thermal expansion coefficient of the material of the outer support ring 110 is greater than the thermal expansion coefficient of the material of the inner support ring 210, the deformation amount of the outer support ring 110 is greater than the deformation amount of the inner support ring 210. At the same time, the relative positions of the outer lens barrel 100 and the inner lens barrel 200 are fixed. The outer support ring 110 deforms towards the inner support ring 210 to further compress the elastic member 400, and the stress is transmitted to the inner support ring 210 and the lens group 300 through the elastic member 400. The stress applied by the outer support ring 110 to the lens group 300 is opposite to the stress generated by the thermal expansion of the lens group 300, and has the effect of suppressing the expansion and movement of the lens group 300. The above structure can also adaptively adjust the lens group 300 in extreme environments with high radiation and strong electromagnetic interference, and maintain high imaging reliability in extreme environments.

[0028] In some embodiments, the inner support ring 210 can be made of Invar, and its thermal expansion coefficient is 1.2×10 -6 / °C, and the outer support ring 110 can be made of titanium alloy Ti-6Al-4V, and its thermal expansion coefficient is 8.6×10-6 / °C. The displacement of the lens group 300 is tested within the temperature range of -40°C to 85°C, and the displacement of the lens group 300 < ±0.05 mm. Among them, when the displacement of the lens group 300 is positive, it refers to the distance that the lens group 300 moves due to expansion in an environment with increasing temperature; when the displacement of the lens group 300 is negative, it refers to the distance that the lens group 300 moves due to contraction in an environment with decreasing temperature.

[0029] Referring to Figure 5 As shown, further, in some embodiments, the elastic member 400 can be an annular wave spring, the thickness of the wave spring can be 0.1 mm, and it has an elastic modulus of 200 GPa.

[0030] Referring to Figure 2 As shown, it can be understood that an annular limiting platform 220 is provided at one end of the endoscope barrel 200 away from the inner support ring 210. The inner support ring 210 is detachably connected to the endoscope barrel 200. One end of the lens group 300 abuts against the limiting platform 220, and the other end of the lens group 300 abuts against the inner support ring 210.

[0031] With the above structure of the endoscope barrel 200, the inner support ring 210 can be disassembled first, and the lens group 300 is inserted into the endoscope barrel 200 from the end of the endoscope barrel 200 for installing the inner support ring 210 until the lens group 300 abuts against the limiting platform 220, and then the inner support ring 210 is installed and the inner support ring 210 also abuts against the lens group 300. The lens group 300 is clamped and positioned by the inner support ring 210 and the limiting platform 220 together, achieving a fixing effect.

[0032] Preferably, in some embodiments, a connecting thread is provided between the inner support ring 210 and the endoscope barrel 200. The abutting stress of the inner support ring 210 on the lens group 300 can be adjusted by changing the tightening torque between the inner support ring 210 and the endoscope barrel 200.

[0033] It can be understood that the lens group 300 includes a plurality of coaxially arranged lenses 310. The endoscope barrel 200 is inserted with a number of positioning rings 500. The positioning rings 500 are located between two adjacent lenses 310, and the lenses 310 abut against the positioning rings 500.

[0034] In the lens group 300, multiple lenses 310 need to be arranged at the designed interval distances to achieve the designed imaging effect. The interval distances between the lenses 310 need to be maintained using the positioning ring 500. Specifically, in some embodiments, the first lens 310 is placed in the endoscope barrel 200, and the first lens 310 abuts against the limiting platform 220 of the endoscope barrel 200. Then, a positioning ring 500 is axially placed, and the positioning ring 500 abuts against the first lens 310. The second lens 310 is continuously placed, and the second lens 310 abuts against the positioning ring 500. Among them, the interval distance between the first lens 310 and the second lens 310 is the same as the axial length of the positioning ring 500.

[0035] It can be understood that, in order to reduce the mechanical stress transfer between the positioning ring 500 and the lens 310, at least three supporting portions 510 are provided on the end face of the positioning ring 500. The multiple supporting portions 510 are evenly distributed circumferentially around the positioning ring 500. Along the axial direction of the positioning ring 500, the surface of the supporting portion 510 protrudes outward from the end face of the positioning ring 500.

[0036] In the above structure, the contact part between the lens 310 and the positioning ring 500 only exists on the surface of the supporting portion 510, and the contact area can be controlled to be less than 1 mm 2 within the range. Preferably, as shown in Figure 3 , the number of the supporting portions 510 is set to three, forming a three-point support structure. At the same time, the material of the supporting portion 510 can use carbon fiber T1100G. Adopting the three-point support structure can also reduce the damage effect of radiation (10 6 Gy) on the lens to <0.02%.

[0037] It can be understood that the gap between the lens 310 and the positioning ring 500 is filled with liquid metal, and the gap between the lens 310 and the limiting platform 220 is also filled with liquid metal. The liquid metal is in a solid state within the range of the first temperature threshold and in a liquid state within the range of the second temperature threshold. Among them, the lens 310 operates within the range of the first temperature threshold.

[0038] During the filling process, the liquid metal is in a liquid state after being heated up. After filling the liquid metal into the gaps between the lens 310 and the limit platform 220, and between the lens 310 and the positioning ring 500, it is necessary to cool down and wait for the liquid metal to turn into a solid state to further fix the lens 310. It should be understood that the range of the second temperature threshold is larger than that of the first temperature threshold, and the lens 310 of the lens operates within the range of the first temperature threshold. That is, in the working environment of the lens, even if the temperature rises, it will not cause the liquid metal to turn into a liquid state again. The liquid metal can achieve a circumferential fixing effect on the lens 310 and also has an axial fixing effect, that is, the liquid metal serves as a connecting layer. Using the liquid metal to connect the lens 310 can minimize the structural stress generated by the connecting layer on the lens 310 as much as possible. When the lens 310 is subjected to stress, it will produce a small deformation, and the deformation will affect the imaging effect of the lens 310.

[0039] It should be understood that, in some embodiments, the liquid metal specifically uses a gallium-indium-zinc alloy and can remain in a solid state at 150 °C. Further, a 10-μm silicon carbide coating can be applied before filling the liquid metal, and after filling the liquid metal, a 10-μm silicon carbide coating can be continuously applied on the surface of the liquid metal, which can effectively prevent the melting and flowing of the liquid metal. Silicon carbide has a high melting point (2700 °C) and a low coefficient of thermal expansion (4.0×10 -6 / °C). It should be understood that the filling thickness of the liquid metal is controlled at 2 μm.

[0040] Refer to Figure 4 As shown, it can be understood that multiple through holes are provided on the barrel walls of the outer barrel 100 and the inner barrel 200, and the multiple through holes form a honeycomb lattice structure.

[0041] For a conventional barrel structure, its natural frequency <500 Hz. When the lens vibrates at >50 Hz, it is easy to cause resonance of the lens 310, which will lead to a decrease in imaging quality, and the decrease amplitude >30%. That is, the conventional barrel structure has poor seismic performance. By respectively providing multiple through holes on the barrel walls of the outer barrel 100 and the inner barrel 200 to form a honeycomb lattice structure, the natural frequencies of the outer barrel 100 and the inner barrel 200 can be increased. In some embodiments, for a barrel with a titanium alloy honeycomb lattice structure, its natural frequency is increased to 1200 Hz. After testing, the vibration attenuation rate >95%. Further, a 200-nm-thick chromium carbide coating can be plated on the surface of the outer barrel 100, which has better hardness, for example, the hardness can reach 25 GPa, and at the same time, the corrosion resistance is improved, and the corrosion resistance is increased by about 10 times.

[0042] It can be understood that a retaining ring 120 is provided at one end of the outer barrel 100 away from the outer support ring 110. The retaining ring 120 is detachably connected to the outer barrel 100, and the retaining ring 120 abuts against the end of the inner barrel 200.

[0043] For the outer lens barrel 100 with the above structure, first remove the retaining ring 120, insert the inner lens barrel 200 into the outer lens barrel 100 from the end of the outer lens barrel 100 where the retaining ring 120 is connected, and the inner support ring 210 on the inner lens barrel 200 faces the outer support ring 110. Then install the retaining ring 120 back onto the outer lens barrel 100 so that the retaining ring 120 abuts against the end of the inner lens barrel 200.

[0044] It can be understood that, preferably, there is a connecting thread between the retaining ring 120 and the outer lens barrel 100. By adjusting the tightening torque of the retaining ring 120, the extrusion force between the inner lens barrel 200 and the elastic member 400 can be adjusted.

[0045] Conventional lenses do not have a compensation structure or only use a spring to compensate and suppress the thermal expansion displacement of the lens group 300, and its displacement > ±0.1 mm, the imaging quality of the lens changes, and the imaging reliability is poor. In some embodiments of the present invention, the inner support ring 210 is made of Invar, with a thermal expansion coefficient of 1.2×10 -6 / °C, the outer support ring 110 is made of titanium alloy, with a thermal expansion coefficient of 8.6×10 -6 / °C. There is a wave spring between the outer support ring 110 and the inner support ring 210, with a thickness of 0.1 mm and an elastic modulus of 200 GPa. When tested in the temperature range of -40°C to 85°C, the displacement of the lens group 300 < ±0.05 mm.

[0046] Conventional lenses use an aluminum alloy lens barrel with a solid structure, with a natural frequency < 500 Hz and a vibration attenuation rate < 60%. In some embodiments of the present invention, the outer lens barrel 100 is made of titanium alloy material, the inner lens barrel 200 is made of Invar material, and both the outer lens barrel 100 and the inner lens barrel 200 are provided with a plurality of through holes to form a honeycomb lattice structure. The natural frequency of the lens can reach 1200 Hz, and the vibration attenuation rate > 95%.

[0047] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made without departing from the spirit of the present invention within the knowledge of those of ordinary skill in the art.

Claims

1. An undriven adaptive lens based on a double-ring support, characterized in that, Comprising: An outer lens barrel (100), one end of the outer lens barrel (100) is provided with an outer support ring (110); An inner lens barrel (200), the inner lens barrel (200) is inserted into the outer lens barrel (100), and one end of the inner lens barrel (200) facing the outer support ring (110) is provided with an inner support ring (210); A lens group (300), the lens group (300) is arranged in the inner lens barrel (200), and the lens group (300) abuts against the inner support ring (210); An elastic member (400), the elastic member (400) is arranged between the outer support ring (110) and the inner support ring (210), and the elastic member (400) is in a compressed state; Wherein, the material of the outer support ring (110) has a larger coefficient of thermal expansion than the material of the inner support ring (210).

2. The driverless adaptive lens based on a double-ring support according to claim 1, wherein One end of the inner lens barrel (200) away from the inner support ring (210) is provided with an annular limiting platform (220), the inner support ring (210) is detachably connected to the inner lens barrel (200), one end of the lens group (300) abuts against the limiting platform (220), and the other end of the lens group (300) abuts against the inner support ring (210).

3. The driverless adaptive lens based on a double-ring support according to claim 2, wherein A connecting thread is provided between the inner support ring (210) and the inner lens barrel (200).

4. The non-driven adaptive lens based on a double-ring support according to claim 2, wherein The lens group (300) includes a plurality of coaxially arranged lenses (310), the inner lens barrel (200) is inserted with a number of positioning rings (500), the positioning rings (500) are located between two adjacent lenses (310), and the lenses (310) abut against the positioning rings (500).

5. The non-driven adaptive lens based on a double-ring support according to claim 4, characterized in that, The end face of the positioning ring (500) is provided with at least three supporting parts (510), and the plurality of supporting parts (510) are evenly distributed around the circumferential direction of the positioning ring (500). Along the axial direction of the positioning ring (500), the surface of the supporting part (510) protrudes outward from the end face of the positioning ring (500).

6. The non-driven adaptive lens based on a double-ring support according to claim 4, characterized in that The gap between the lens (310) and the positioning ring (500) is filled with liquid metal, and the gap between the lens (310) and the limiting platform (220) is also filled with liquid metal. The liquid metal is in a solid state within the range of the first temperature threshold and in a liquid state within the range of the second temperature threshold. Wherein, the lens (310) operates within the range of the first temperature threshold.

7. The driverless adaptive lens based on a double-ring support according to claim 1, wherein The barrel walls of the outer lens barrel (100) and the inner lens barrel (200) are both provided with a plurality of through holes, and the plurality of through holes form a honeycomb lattice structure.

8. The driverless adaptive lens based on a double-ring support according to claim 1, characterized in that One end of the outer lens barrel (100) away from the outer support ring (110) is provided with a retaining ring (120), the retaining ring (120) is detachably connected to the outer lens barrel (100), and the retaining ring (120) abuts against the end of the inner lens barrel (200).

9. The non-driven adaptive lens based on a double-ring support according to claim 8, characterized in that, A connecting thread is provided between the retaining ring (120) and the outer lens barrel (100).

10. The driverless adaptive lens based on a double-ring support according to claim 1, wherein The elastic member (400) is an annular corrugated spring.

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