Dual ring support based drive-free adaptive lens

Abstract

This invention discloses a driverless adaptive lens based on dual-ring support, relating to the field of optical lens technology. It includes an outer lens barrel, an inner lens barrel, a lens group, and an elastic element. One end of the outer lens barrel has an outer support ring; the inner lens barrel is inserted into the outer lens barrel, and the end of the inner lens barrel facing the outer support ring has an inner support ring; the lens group is disposed in the inner lens barrel, and the lens group abuts against the inner support ring; the elastic element is disposed between the outer and inner support rings, and the elastic element is in a compressed state; wherein, the coefficient of thermal expansion of the material of the outer support ring is greater than that of the material of the inner support ring. The driverless adaptive lens based on dual-ring support of this invention can maintain high imaging reliability in extreme environments.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and in particular to a driveless adaptive lens based on double-ring support. Background Technology

[0002] Existing optical lenses suffer from insufficient thermal stability. In environments with large temperature variations, such as temperature fluctuations from -20°C to 60°C, lens assembly displacement can reach ±0.1mm. Some lenses incorporate voice coil motors or piezoelectric ceramics to drive the lens assembly movement and adjust it, overcoming lens assembly displacement caused by temperature changes. However, both voice coil motor and piezoelectric ceramic-driven solutions are highly susceptible to failure in extreme environments with high radiation and strong electromagnetic interference. Summary of the Invention

[0003] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention proposes a driveless adaptive lens based on double-ring support, which can maintain high imaging reliability in extreme environments.

[0004] According to an embodiment of the present invention, a driveless adaptive lens based on double-ring support includes an outer lens barrel, one end of which is provided with an outer support ring; An endoscope tube is inserted into an outer endoscope tube, and an inner support ring is provided at one end of the endoscope tube facing the outer support ring; A lens assembly is disposed in the endoscope tube and abuts against the inner support ring; An elastic element is provided between the outer support ring and the inner support ring, and the elastic element is in a compressed state; The outer support ring has a greater coefficient of thermal expansion than the inner support ring.

[0005] The driveless adaptive lens based on double-ring support according to embodiments of the present invention has at least the following beneficial effects: an elastic element is provided between the inner support ring and the outer support ring, creating a floating space. During the process of increasing ambient temperature, the lens assembly expands due to heat, generating stress towards the outer support ring. The inner and outer support rings expand synchronously due to heat. Because the thermal expansion coefficient of the outer support ring is greater than that of the inner support ring, the deformation of the outer support ring is greater than that of the inner support ring. At the same time, the relative positions of the outer and inner lens barrels are fixed. The deformation of the outer support ring towards the inner support ring further compresses the elastic element. The stress is transmitted to the inner support ring and the lens assembly through the elastic element. The stress applied by the outer support ring to the lens assembly is opposite in direction to the stress generated by the thermal expansion of the lens assembly, thus suppressing the expansion and movement of the lens assembly. The above structure can also adaptively adjust the lens assembly even in extreme environments with high radiation and strong electromagnetic interference, maintaining high imaging reliability in extreme environments.

[0006] According to some embodiments of the present invention, an annular limiting platform is provided at one end of the endoscope tube away from the inner support ring, the inner support ring is detachably connected to the endoscope tube, one end of the lens assembly abuts against the limiting platform, and the other end of the lens assembly abuts against the inner support ring.

[0007] According to some embodiments of the present invention, the inner support ring and the endoscope tube are provided with connecting threads.

[0008] According to some embodiments of the present invention, the lens assembly includes a plurality of coaxially arranged lenses, and the endoscope tube is fitted with a plurality of positioning rings, the positioning rings being located between two adjacent lenses, and the lenses abutting against the positioning rings.

[0009] According to some embodiments of the present invention, the end face of the positioning ring is provided with at least three support portions, and the plurality of support portions are evenly distributed around the circumference of the positioning ring. Along the axial direction of the positioning ring, the surface of the support 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 stage is also filled with liquid metal. The liquid metal is solid when it is within a first temperature threshold range, and liquid when it is within a second temperature threshold range. The lens operates within the first temperature threshold range.

[0011] According to some embodiments of the present invention, both the outer endoscope tube and the inner endoscope tube have multiple through holes in their tube walls, and the multiple through holes form a honeycomb dot matrix structure.

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

[0013] According to some embodiments of the present invention, the retaining ring and the outer lens barrel are provided with connecting threads.

[0014] According to some embodiments of the present invention, the elastic element is a ring-shaped wave spring.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1This is a cross-sectional structural diagram of a driveless adaptive lens based on double-ring support according to an embodiment of the present invention; Figure 2 This is a partially enlarged schematic diagram of the undriven adaptive lens based on double-ring support according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the positioning ring structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the unfolded structure of the outer tube wall of an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of an elastic element according to an embodiment of the present invention.

[0017] Icon labels: Outer tube 100, outer support ring 110, retaining ring 120, inner tube 200, inner support ring 210, limiting stage 220, lens group 300, lens 310, elastic element 400, positioning ring 500, support part 510. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to 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 invention.

[0020] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0021] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0022] In an optical lens, a lens group contains multiple lenses, which are arranged in a designed order, and the spacing between adjacent lenses must be controlled within a designed range. At the same time, the position of the entire lens group within the lens barrel is relatively fixed to achieve optimal imaging results.

[0023] As described in the background section, in environments with large temperature variations, the displacement of the lens group can lead to a deterioration in the image quality of the lens. Although the lens group can be actively moved for adjustment, active driving becomes unreliable in extreme environments. For example, environments with high radiation or strong electromagnetic interference can affect the control of active driving and prevent the desired adjustments from being made.

[0024] Reference Figure 1 As shown, an embodiment of the present invention, a driveless adaptive lens based on double-ring support, includes an outer lens barrel 100, an inner lens barrel 200, a lens group 300, and an elastic element 400.

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

[0026] An elastic element 400 is provided between the inner support ring 210 and the outer support ring 110. The elastic element 400 can deform under force and has a floating space. During the process of rising ambient temperature, the lens assembly 300 expands due to heat and moves towards the floating space to release stress. That is, the lens assembly 300 has stress in the direction of the outer support ring 110.

[0027] As the ambient temperature rises, the inner support ring 210 and the outer support ring 110 expand synchronously due to heat. Because the coefficient of thermal expansion of the material of the outer support ring 110 is greater than that of the inner support ring 210, the deformation of the outer support ring 110 is greater than that of the inner support ring 210. Simultaneously, 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 element 400. The stress is transmitted to the inner support ring 210 and the lens assembly 300 through the elastic element 400. The stress applied to the lens assembly 300 by the outer support ring 110 is opposite in direction to the stress generated by the thermal expansion of the lens assembly 300, thus suppressing the expansion and movement of the lens assembly 300. This structure can adaptively adjust the lens assembly 300 even in extreme environments with high radiation and strong electromagnetic interference, maintaining high imaging reliability in extreme environments.

[0028] In some embodiments, the inner support ring 210 may be made of Invar steel, which has a coefficient of thermal expansion of 1.2 × 10⁻⁶. -6 / ℃, the outer support ring 110 can be made of titanium alloy Ti-6Al-4V, whose coefficient of thermal expansion is 8.6×10.-6 / ℃. When tested within a temperature range of -40℃ to 85℃, the displacement of lens group 300 is < ±0.05mm. Positive displacement of lens group 300 refers to the distance moved by lens group 300 as it expands in an environment with increasing temperature; negative displacement refers to the distance moved by lens group 300 as it contracts in an environment with decreasing temperature.

[0029] Reference Figure 5 As shown, further, in some embodiments, the elastic element 400 may be a ring-shaped wave spring with a thickness of 0.1 mm and an elastic modulus of 200 GPa.

[0030] Reference Figure 2 As shown, it can be understood that the end of the endoscope tube 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 endoscope tube 200. One end of the lens assembly 300 abuts against the limiting platform 220, and the other end of the lens assembly 300 abuts against the inner support ring 210.

[0031] With the aforementioned structure, the endoscope tube 200 can be pre-disassembled. The lens assembly 300 is then inserted into the endoscope tube 200 from the end where the inner support ring 210 is installed, until the lens assembly 300 abuts against the limiting stage 220. Then, the inner support ring 210 is installed, ensuring it also abuts against the lens assembly 300. The lens assembly 300 is held and positioned by both the inner support ring 210 and the limiting stage 220, achieving a fixed fixation effect.

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

[0033] It is understood that the lens assembly 300 includes multiple coaxially arranged lenses 310, and the endoscope tube 200 is fitted with several 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 according to a designed interval to achieve the designed imaging effect. The interval between the lenses 310 is maintained using a positioning ring 500. Specifically, in some embodiments, the first lens 310 is placed in the endoscope tube 200 and abuts against the limiting stage 220 of the endoscope tube 200. Then, a positioning ring 500 is placed axially, abutting against the first lens 310. A second lens 310 is then placed, abutting against the positioning ring 500. The interval between the first and second lenses 310 is the same as the axial length of the positioning ring 500.

[0035] Understandably, in order to reduce the mechanical stress transmission between the positioning ring 500 and the lens 310, the end face of the positioning ring 500 is provided with at least three support portions 510. The multiple support portions 510 are evenly distributed around the circumference of the positioning ring 500, and along the axial direction of the positioning ring 500, the surface of the support portion 510 protrudes outward from the end face of the positioning ring 500.

[0036] In the above structure, the contact area between the lens 310 and the positioning ring 500 exists only on the surface of the support portion 510, which can control the contact area to less than 1 mm. 2 Within the range. Preferably, refer to Figure 3 As shown, the number of support parts 510 is set to three, forming a three-point support structure. Furthermore, the material of the support parts 510 can be carbon fiber T1100G. The three-point support structure also helps to reduce the radiation (10) 6 The damage effect of Gy on the lens is reduced to <0.02%.

[0037] It is 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 stage 220 is also filled with liquid metal. The liquid metal is solid when it is within the range of the first temperature threshold, and liquid metal is liquid when it is within the range of the second temperature threshold. The lens 310 operates within the range of the first temperature threshold.

[0038] During the filling process, the liquid metal is heated to a liquid state. After filling the gaps between lens 310 and limiting stage 220, and between lens 310 and positioning ring 500, the liquid metal needs to be cooled to solidify, further securing lens 310. It's important to understand that the second temperature threshold range is greater than the first temperature threshold range, and lens 310 operates within the first temperature threshold range. This means that even if the temperature rises in the working environment, the liquid metal will not re-liquidate. The liquid metal provides circumferential and axial fixation for lens 310, acting as a connecting layer. Using liquid metal to connect lens 310 minimizes the structural stress exerted on lens 310 by the connecting layer. Stress on lens 310 causes slight deformation, which affects its imaging performance.

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

[0040] Reference Figure 4 As shown, it can be understood that the walls of both the outer tube 100 and the inner tube 200 are provided with multiple through holes, which form a honeycomb dot matrix structure.

[0041] Conventional lens barrel structures have a natural frequency <500Hz. Vibrations above 50Hz can easily induce 310 resonance in the lens elements, leading to a decrease in image quality of >30%, indicating poor vibration resistance. By creating multiple through-holes in the walls of the outer lens barrel 100 and inner lens barrel 200 to form a honeycomb lattice structure, the natural frequencies of both the outer and inner lens barrels can be increased. In some embodiments, the titanium alloy honeycomb lattice structure of the lens barrel raises the natural frequency to 1200Hz, with a vibration attenuation rate >95% after testing. Furthermore, the surface of the outer lens barrel 100 can be coated with a 200nm thick chromium carbide coating, providing better hardness (e.g., up to 25GPa) and improved corrosion resistance by approximately 10 times.

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

[0043] In the outer scope 100 with the above structure, the retaining ring 120 is first removed, and the inner scope 200 is inserted into the outer scope 100 from the end of the outer scope 100 connected to the retaining ring 120, with the inner support ring 210 facing the outer support ring 110 on the inner scope 200. Then, the retaining ring 120 is installed back into the outer scope 100, so that the retaining ring 120 abuts against the end of the inner scope 200.

[0044] It is understood that, preferably, the retaining ring 120 and the outer endoscope barrel 100 are provided with connecting threads. By adjusting the tightening torque of the retaining ring 120, the compressive force between the inner endoscope barrel 200 and the elastic element 400 can be adjusted.

[0045] Conventional lenses lack compensation structures or rely solely on springs to compensate for and suppress the thermal expansion displacement of the lens group 300. This displacement exceeds ±0.1mm, altering the lens's image quality and reducing its reliability. In some embodiments of this invention, the inner support ring 210 is made of Invar steel, with a coefficient of thermal expansion of 1.2 × 10⁻⁶. -6 / ℃, the outer support ring 110 is made of titanium alloy with a coefficient of thermal expansion of 8.6×10. -6 / ℃, a wave spring with a thickness of 0.1mm and an elastic modulus of 200GPa is provided between the outer support ring 110 and the inner support ring 210. When tested in a temperature range of -40℃ to 85℃, the displacement of the lens group 300 is <±0.05mm.

[0046] Conventional lenses use a solid aluminum alloy lens barrel with a natural frequency <500Hz and a vibration attenuation rate <60%. In some embodiments of the present invention, the outer lens barrel 100 is made of titanium alloy, and the inner lens barrel 200 is made of Invar steel. Both the outer lens barrel 100 and the inner lens barrel 200 are provided with multiple through holes to form a honeycomb dot matrix structure, and the natural frequency of the lens can reach 1200Hz, with a 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. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A driverless adaptive lens based on double-ring support, characterized in that, include: An outer lens tube (100) is provided with an outer support ring (110) at one end of the outer lens tube (100). An endoscope tube (200) is inserted into an outer endoscope tube (100), and an inner support ring (210) is provided at one end of the endoscope tube (200) facing the outer support ring (110). Lens assembly (300), the lens assembly (300) is disposed in the endoscope tube (200), and the lens assembly (300) abuts against the inner support ring (210); An elastic element (400) is disposed between the outer support ring (110) and the inner support ring (210), and the elastic element (400) is in a compressed state; The outer support ring (110) has a greater coefficient of thermal expansion than the inner support ring (210).

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

3. The driverless adaptive lens based on double-ring support according to claim 2, characterized in that, The inner support ring (210) and the endoscope tube (200) are provided with connecting threads.

4. The driverless adaptive lens based on double-ring support according to claim 2, characterized in that, The lens assembly (300) includes a plurality of coaxially arranged lenses (310), and the endoscope tube (200) is fitted with a plurality 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 driverless adaptive lens based on double-ring support according to claim 4, characterized in that, The end face of the positioning ring (500) is provided with at least three support portions (510), and the plurality of support portions (510) are evenly distributed around the circumference of the positioning ring (500). Along the axial direction of the positioning ring (500), the surface of the support portion (510) protrudes outward from the end face of the positioning ring (500).

6. The driverless adaptive lens based on 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 stage (220) is also filled with liquid metal. The liquid metal is solid when it is within a first temperature threshold range, and liquid when it is within a second temperature threshold range. The lens (310) operates within the first temperature threshold range.

7. The driverless adaptive lens based on double-ring support according to claim 1, characterized in that, The outer endoscope tube (100) and the inner endoscope tube (200) are both provided with multiple through holes in their tube walls, and the multiple through holes form a honeycomb dot matrix structure.

8. The driverless adaptive lens based on double-ring support according to claim 1, characterized in that, The outer end of the endpiece tube (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 endpiece tube (100), and the retaining ring (120) abuts against the end of the inner endpiece tube (200).

9. The driverless adaptive lens based on double-ring support according to claim 8, characterized in that, The retaining ring (120) and the outer lens barrel (100) are provided with connecting threads.

10. The driverless adaptive lens based on double-ring support according to claim 1, characterized in that, The elastic element (400) is a ring-shaped wave spring.

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