Infrared continuous zoom lens with temperature self-adapting structure

Abstract

The application relates to the technical field of zoom lenses, and particularly discloses an infrared continuous zoom lens with a temperature self-adaptive structure, which comprises an objective lens end fixing piece, a zoom assembly assembly fixing piece and an ocular end fixing piece which are coaxially connected, the inner cavity of the zoom assembly assembly fixing piece is provided with a zoom mechanism and a compensation mechanism, and the outer side is provided with an adjusting driving piece; the zoom mechanism comprises a zoom sliding base, a radial guide bushing and a cam guide pin piece; and the zoom sliding base is slidably arranged in the radial guide bushing. The infrared continuous zoom lens with the temperature self-adaptive structure realizes self-adaptive compensation of a cam transmission gap by means of elastic pieces and thermal expansion materials, and is matched with double-expansion-coefficient buffer pads to eliminate a guide radial gap, does not need active temperature control, has a low-power-consumption miniaturized structure, and the zoom compensation mechanism is synchronously adapted, so that the infrared continuous zoom lens has the advantages of no empty return, no jamming and stagnation in a wide temperature range, no light axis deviation, stable imaging in a full focal length section, improved lens reliability and application range.

Description

Technical Field

[0001] This invention relates to the field of infrared zoom lens technology, specifically to an infrared continuous zoom lens with a temperature adaptive structure. Background Technology

[0002] Infrared continuous zoom lenses can continuously adjust the focal length without changing the distance between the object and the image, taking into account both large field of view search and observation and small field of view detail identification. They are widely used in security monitoring, vehicle night vision, industrial temperature measurement and national defense optoelectronic detection and other fields. As application scenarios continue to expand, infrared lenses often need to operate in a wide temperature range of -40℃ to 60℃. Temperature changes will have a significant impact on the imaging performance and mechanical motion accuracy of the optical system. For example, Chinese Patent CN109116530B discloses a short-wave infrared optical athermalized continuous zoom lens. The optical system of the lens includes a front fixed group A with positive optical power, a zoom group B with negative optical power, a compensation group C with positive optical power, an aperture D, and a rear fixed group E with positive optical power. The front fixed group A includes a first cemented group in which a positive meniscus lens A-1, a negative meniscus lens A-2, and a positive meniscus lens A-3 are closely bonded. The zoom group B includes a second cemented group in which a biconcave lens B-1, a positive meniscus lens B-2, and a biconcave lens B-3 are closely bonded. The compensation group C includes a third cemented group in which a biconvex lens C-1, a negative meniscus lens C-2, and a positive meniscus lens C-3 are closely bonded. The rear fixed group E includes a positive meniscus lens E-1, a negative meniscus lens E-2, and a biconvex lens E-3. The lens of this invention achieves the fastest zoom, resulting in a small lead path, short total optical length, compact system size, wide operating temperature range, and no need for frequent refocusing.

[0003] Based on practical use of infrared zoom lenses, some drawbacks have been found in their application, such as: 1. Infrared optical materials have a thermal refractive index effect. Combined with the thermal expansion and contraction characteristics of optical elements and lens structures, temperature changes can cause focal length drift, image plane shift and optical axis eccentricity, resulting in decreased image clarity and difficulty in maintaining stable optical performance. 2. Continuous zoom lenses rely on a cam guide pin mechanism to drive the lens group movement. There are fit gaps between the guide pin and the cam groove, and between the guide bushing and the inner wall of the lens barrel. At high temperatures, the expansion of the components can easily lead to increased gaps, transmission backlash, and decreased positioning accuracy. At low temperatures, the contraction of the components can easily lead to excessively tight fits, movement stagnation, or even mechanism jamming, which seriously affects the stability of zoom. 3. Existing active temperature control solutions maintain a constant lens temperature by using built-in heating and cooling components. Although the compensation effect is stable, it significantly increases the system size, power consumption and manufacturing cost, making it unsuitable for miniaturized, low-power portable and automotive applications.

[0004] Therefore, we propose an infrared continuous zoom lens with a temperature-adaptive structure to address the problems mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide an infrared continuous zoom lens with a temperature adaptive structure to solve the problems mentioned in the background art, such as imaging shift and cam drive and guide pair gap changes caused by thermal expansion and contraction when the existing infrared zoom lens operates in a wide temperature range, high cost and power consumption of active temperature control, and the inability of ordinary passive compensation to compensate only locally and eliminate zoom back, jamming and optical axis eccentricity defects under high and low temperatures.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an infrared continuous zoom lens with a temperature adaptive structure, comprising a coaxially connected objective lens end fixing component, a zoom component assembly fixing component, and an eyepiece end fixing component. The inner cavity of the zoom component assembly fixing component is provided with a zoom mechanism and a compensation mechanism, and the outer side is provided with an adjustment drive component. The zoom mechanism includes a zoom slide, a radial guide bushing, and a cam guide pin. The zoom slide is slidably disposed inside the radial guide bushing. The side wall of the radial guide bushing is provided with a guide vertical groove, and the side wall of the zoom component assembly fixing component is provided with a zoom curved groove. The cam guide pin assembly includes a guide pin spindle, a tapered bushing, an elastic element, and a thermal expansion material block. The inner end of the guide pin spindle is inserted into a guide pin mounting blind hole opened on the side of the variable magnification slide. The elastic element is connected between the guide pin mounting blind hole and the guide pin spindle. A tapered bushing is sleeved on the outer side of the guide pin spindle. The thermal expansion material block is installed at the bottom of the guide pin mounting blind hole.

[0007] Furthermore: a central retaining ring is integrally provided in the middle of the guide pin spindle, and an end protrusion ring is integrally provided at the outer end. The tapered bushing is coaxially sleeved on the outside of the guide pin spindle, with its inner end abutting against the central retaining ring. The outer surface of the tapered bushing has a tapered inclined structure that is narrow on the outside and wide on the inside.

[0008] Furthermore: the elastic element is coaxially sleeved on the outside of the guide pin spindle, and the two ends of the elastic element respectively abut against the inner end face of the end protrusion ring and the port side wall of the guide pin mounting blind hole.

[0009] Furthermore, both the upper and lower ends of the outer side of the variable-amplification slide are fixed with fitting washers, and the outer circular surface of the fitting washers slides and fits against the inner wall of the radial guide bushing.

[0010] Furthermore, the outer side of the radial guide bushing is provided with an adaptive fitting element, and the outer surface of the adaptive fitting element is fitted with the inner wall of the zoom component assembly fastener.

[0011] Furthermore: the adaptive fitting component includes a fixed ring, a first fitting buffer pad and a second fitting buffer pad. The fixed ring is coaxially fixed to the outer wall of the radial guide bushing. The first fitting buffer pad and the second fitting buffer pad are stacked on the inner side of the fixed ring, and the two are made of materials with different coefficients of thermal expansion.

[0012] Furthermore: the compensation mechanism includes a compensation slide, a compensation group guide bushing, and a compensation curve groove. The compensation slide is slidably disposed inside the compensation group guide bushing, and the compensation curve groove is formed on the upper side wall of the variable magnification component assembly fixture.

[0013] Furthermore: the side wall of the compensation group guide bushing is provided with a guide vertical groove, and the cam guide pin passes through the compensation curve groove and the guide vertical groove, with its inner end connected to the side wall of the compensation slide.

[0014] Furthermore: an adaptive fitting element is provided on the outer side of the compensation group guide bushing, and a fitting washer is provided between the compensation slide and the compensation group guide bushing.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: the infrared continuous zoom lens with temperature adaptive structure relies on elastic elements and thermal expansion materials to achieve adaptive compensation of cam transmission clearance, and is equipped with a double expansion coefficient buffer pad to eliminate guide radial clearance. It does not require active temperature control, has a low power consumption and is miniaturized, and the zoom compensation mechanism is synchronously adapted. It has a wide temperature range without backlash or jamming, suppresses optical axis offset, and provides stable imaging across the entire focal length, thereby improving the reliability and applicability of the lens. 1. This invention incorporates a combination structure of an elastic element and a thermally expanding material block within the cam guide pin component. At room temperature, the preload of the elastic element pushes the guide pin spindle to tightly fit the tapered bushing against the groove wall, eliminating machining and assembly gaps. At high temperatures, the thermally expanding material block expands, further pushing the guide pin outward to offset the gap increase caused by the expansion of the metal components. This maintains a gapless fit between the cam transmission pair throughout the entire process, solving the problems of zooming back and decreased positioning accuracy caused by dynamic gap changes at high and low temperatures in traditional structures. This significantly improves the stability of zooming motion and the accuracy of position control. 2. The present invention provides an adaptive fitting component on the outside of the guide bushing, which is composed of two types of buffer pads with different thermal expansion coefficients. In high temperature environment, the buffer pad with high thermal expansion coefficient fills the radial gap, while in low temperature environment, the buffer pad with low thermal expansion coefficient maintains effective support. Through the complementary difference in thermal expansion characteristics, the guide bushing and the inner wall of the lens barrel are kept in close contact and coaxial positioning throughout the process, avoiding radial wobble of the bushing and optical axis offset caused by temperature fluctuations, and greatly improving the temperature stability of the optical system. 3. The compensation mechanism of this invention adopts a guiding structure and a temperature adaptive structure that are completely consistent with the zoom mechanism. Both have the same motion accuracy and temperature response characteristics. During zooming, the displacement synchronization of the zoom lens and the compensation lens is high and the matching accuracy is good, which can accurately compensate for the image plane shift caused by zooming. At the same time, with the cooperation of two-dimensional mechanical gap temperature compensation, the image plane drift caused by temperature is effectively suppressed, ensuring that the lens can maintain a clear and stable imaging effect in a wide temperature range and the entire focal length range. 4. This invention relies entirely on the pre-tensioning of elastic elements and the thermal expansion characteristics of materials to achieve temperature adaptive compensation. It does not require built-in active temperature control components such as heating and cooling, nor does it require additional power supply and control circuits. While greatly improving environmental adaptability, it effectively controls the system size, weight and power consumption, making it suitable for various miniaturized and low-power application scenarios such as vehicle night vision, portable detection, and security monitoring. It overcomes the shortcomings of active temperature control solutions, such as high cost, large size and high power consumption. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a top view of the overall structure of the lens of the present invention; Figure 2 This is a schematic diagram of the overall lens structure of the present invention viewed from below; Figure 3 This is a schematic diagram of the cross-sectional structure of the lens of the present invention; Figure 4 This is an exploded structural diagram of the variable magnification assembly fixing component, radial guide bushing, and variable magnification slide of the present invention. Figure 5 This is a schematic diagram of the overall structure of the adaptive bonding component of the present invention; Figure 6 This is an exploded structural diagram of the cam guide pin component of the present invention; Figure 7 For the present invention Figure 3 Enlarged schematic diagram of the cam guide pin assembly at point A; Figure 8 This is a schematic diagram of the overall assembly structure of the compensation slide of the present invention.

[0017] In the figure: 1. Objective lens end fixture; 2. Magnification assembly fixture; 3. Eyepiece end fixture; 4. Magnification slide; 41. Guide pin mounting blind hole; 5. Compensation slide; 6. Radial guide bushing; 7. Adaptive fitting component; 701. Fixing ring; 702. First fitting buffer pad; 703. Second fitting buffer pad; 8. Fitting washer; 9. Cam guide pin component; 901. Guide pin spindle; 902. Conical bushing; 903. End convex ring; 904. Middle retaining ring; 905. Elastic component; 906. Thermal expansion material block; 10. Guide vertical groove; 11. Magnification curve groove; 12. Adjustment drive component; 13. Compensation group guide bushing; 14. Compensation curve groove. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] Please see Figures 1-8 The present invention provides the following technical solution: an infrared continuous zoom lens with a temperature adaptive structure, comprising: I. Overall lens barrel and fixed optical structure The infrared continuous zoom lens is arranged coaxially from the object side to the image side along the optical axis, consisting of an objective lens end fixing component 1, a zoom assembly fixing component 2, and an eyepiece end fixing component 3. These three components are fixedly connected to form the main lens barrel. The objective lens end fixing component 1 has a rigid objective lens fixing lens group installed inside. The zoom assembly fixing component 2 has an intermediate lens group installed inside. The eyepiece end fixing component 3 has a rigid eyepiece fixing lens group installed inside. Each fixing lens group is arranged coaxially with the lens barrel.

[0020] In specific application scenarios, during assembly, each fixed lens group is first pressed and bonded to the corresponding reference surface of the inner cavity of the fixing component. Then, the objective lens end fixing component 1, the zoom component assembly fixing component 2, and the eyepiece end fixing component 3 are sequentially coaxially connected along the optical axis and positioned by the end face stop to form a complete lens barrel body. During operation, all fixed lens groups maintain a constant axial position, providing a fixed refraction and focusing reference for the optical path. All moving optical components are adjusted axially based on this coaxial reference.

[0021] The above technical solution was adopted to build the main mechanical frame of the lens and the fixed optical path base, ensuring the coaxiality of the installation of each moving component, and providing a unified structural benchmark for subsequent zoom and temperature adaptive functions.

[0022] II. Variable magnification mechanism guide assembly structure The zoom mechanism is provided in the lower inner cavity of the zoom component assembly fixture 2. The zoom mechanism includes a zoom slide 4, a radial guide bushing 6, a fitting washer 8, a guide vertical groove 10, and a zoom curved groove 11. The zoom slide 4 is coaxially arranged in the lower inner cavity of the zoom component assembly fixture 2, and a zoom lens assembly is rigidly installed inside it. The radial guide bushing 6 is coaxially sleeved on the outside of the zoom slide 4. Fitting washers 8 are fixed at both the upper and lower ends of the outside of the zoom slide 4. The outer circular surface of the fitting washer 8 slides and fits against the inner wall of the radial guide bushing 6. The side wall of the radial guide bushing 6 is provided with a guide vertical groove 10 extending axially. The lower side wall of the zoom component assembly fixture 2 is provided with a zoom curved groove 11 corresponding to the position of the guide vertical groove 10.

[0023] In specific application scenarios, during assembly, the fitting gasket 8 is first assembled and glued to the outer circular steps at the upper and lower ends of the zoom slide 4. Then, the entire zoom slide 4 is pushed axially into the inner cavity of the radial guide bushing 6, so that the outer circular surface of the fitting gasket 8 is in close contact with the inner wall surface of the radial guide bushing 6. During the zooming motion, when the zoom slide 4 moves axially under the action of the cam transmission force, the fitting gasket 8 slides and supports along the inner wall of the radial guide bushing 6. The guide vertical groove 10 and the cam guide pin 9 cooperate to restrict the circumferential rotation of the zoom slide 4, so that it can only make linear reciprocating motion along the optical axis.

[0024] The above technical solution is adopted: by the double-layer cooperation of radial guide bushing 6 and fitting washer 8, the guiding accuracy and cooperation stability of the axial movement of variable magnification slide 4 are improved, the risk of sliding jamming is reduced, and the straightness of variable magnification movement is guaranteed.

[0025] III. Temperature Adaptive Gap Compensation Structure for Cam Guide Pins The cam guide pin 9 is radially perforated by a variable magnification curved groove 11 and a guide vertical groove 10. Its inner end is installed inside a guide pin mounting blind hole 41 on the side wall of the variable magnification slide block 4. The cam guide pin 9 consists of a guide pin main shaft 901, a tapered bushing 902, an end convex ring 903, a middle retaining ring 904, an elastic element 905, and a thermally expanding material block 906. The guide pin main shaft 901 has a central retaining ring 904 integrally formed in the middle and an end convex ring 903 integrally formed at its outer end. The tapered bushing 902... 2. The guide pin is coaxially sleeved on the outside of the guide pin spindle 901. Its outer surface has a tapered inclined structure that is narrow on the outside and wide on the inside. The inner end of the guide pin spindle 901 is inserted into the guide pin mounting blind hole 41. A thermal expansion material block 906 is fixed at the bottom of the blind hole and abuts against the inner end face of the guide pin spindle 901. The elastic element 905 is coaxially sleeved on the outside of the guide pin spindle 901. Its two ends abut against the inner end face of the end protrusion ring 903 and the port side wall of the guide pin mounting blind hole 41, respectively. The elastic element 905 is in a pre-compressed state under normal conditions.

[0026] In specific application scenarios, during assembly, the thermal expansion material block 906 is first placed into the bottom of the guide pin mounting blind hole 41 and bonded in place. Then, the elastic element 905 and the tapered bushing 902 are sequentially mounted on the guide pin spindle 901, with the inner end of the tapered bushing 902 abutting against the central retaining ring 904. Subsequently, the inner end of the guide pin spindle 901 is inserted into the guide pin mounting blind hole 41, and the elastic element 905 is compressed to the preset preload to complete the positioning. The elastic element 905 can be a cylindrical compression spring, an elastic rubber washer, a disc-shaped spring, or a wave-shaped elastic washer. When working at room temperature, the rebound thrust of the elastic element 905 acts on the end convex ring 903, driving the guide pin spindle 901 to push out radially, so that the conical surface of the conical bushing 902 is in close contact with the groove wall of the variable-amplification curve groove 11 and the guide vertical groove 10, eliminating the fit gap caused by machining and assembly. When working in a high-temperature environment, the thermal expansion material block 906 expands in volume due to heat, and squeezes the inner end face of the guide pin spindle 901 radially outward, offsetting the gap increase caused by the thermal expansion of the metal groove, and maintaining the tight fit between the conical bushing 902 and the groove wall.

[0027] The above technical solution is adopted: through the dual action of the elastic element 905 and the thermal expansion material block 906, the matching gap between the cam groove and the guide pin is automatically compensated within a wide temperature range, eliminating backlash and jamming during the zooming process, and improving the stability and positioning accuracy of the zooming motion under high and low temperature environments.

[0028] IV. Synchronous Transmission Structure of Compensation Mechanism The upper inner cavity of the zoom component assembly fixture 2 is equipped with a compensation mechanism, which includes a compensation slide 5, a compensation group guide bushing 13, a fitting washer 8, a guide vertical groove 10, a compensation curve groove 14, and a cam guide pin 9. The compensation slide 5 is coaxially arranged and the compensation lens group is rigidly installed inside. The compensation group guide bushing 13 is coaxially sleeved on the outside of the compensation slide 5, and a fitting washer 8 is also provided between the two. The side wall of the compensation group guide bushing 13 has a guide vertical groove 10. The upper side wall of the zoom component assembly fixture 2 has a compensation curve groove 14. The cam guide pin 9 passes through the compensation curve groove 14 and the guide vertical groove 10 in a radial direction and is then fixed to the side wall of the compensation slide 5. Its installation and matching method is completely consistent with the zoom mechanism. An adjustment drive 12 is installed on the outside of the zoom component assembly fixture 2. The adjustment drive 12 is connected to the zoom mechanism and the compensation mechanism.

[0029] In specific application scenarios, during assembly, the compensation slide 5, compensation group guide bushing 13, fitting washer 8, and cam guide pin 9 are assembled in the same order as the zoom mechanism. After assembly, they are inserted into the corresponding positions in the upper inner cavity of the zoom component assembly fixing part 2. During zooming, the drive component 12 is adjusted to output rotational torque, which simultaneously drives the upper and lower cam guide pins 9 to slide along the trajectory of zoom curve groove 11 and compensation curve groove 14, respectively. This causes the zoom slide 4 and compensation slide 5 to make synchronous axial displacement according to the preset cam curve law. The compensation slide 5 drives the compensation lens group to move accordingly, compensating for the image plane offset generated during zooming in real time.

[0030] The above technical solution ensures that the compensation mechanism and the zoom mechanism have consistent guiding accuracy and temperature adaptive characteristics, guaranteeing the synchronization and coordination accuracy of zoom and compensation movements, and ensuring stable imaging quality across the entire focal length and temperature range.

[0031] V. Temperature-Adaptive Fitting Structure for Guide Bushings Among them, the radial guide bushing 6 and the compensation group guide bushing 13 are provided with adaptive fitting parts 7 on the outer sides of the upper and lower ends. The adaptive fitting parts 7 are composed of a fixed ring 701, a first fitting buffer pad 702, and a second fitting buffer pad 703. The fixed ring 701 is coaxially fixed to the outer wall of the bushing. The first fitting buffer pad 702 and the second fitting buffer pad 703 are both annular, stacked and overlapped between the fixed ring 701. The outer circular surfaces of both are tightly fitted to the inner wall of the zoom component assembly fixing part 2. The first fitting buffer pad 702 and the second fitting buffer pad 703 are made of materials with different coefficients of thermal expansion.

[0032] In specific application scenarios, during assembly, the adaptive fitting component 7 is bonded and fixed to the upper and lower outer wall steps of the radial guide bushing 6 and the compensation group guide bushing 13 respectively by the fixing ring 701. After the bushing is inserted into the inner cavity of the zoom component assembly fixing component 2, the first fitting buffer pad 702 and the second fitting buffer pad 703 are both bonded to the inner wall of the lens barrel under slight pressure. When the temperature changes during operation, the buffer pad with a high thermal expansion coefficient has a greater thermal expansion in the high temperature environment, and the radial thickness increases, filling the radial gap between the bushing and the lens barrel caused by the difference in metal thermal expansion. In the low temperature environment, the buffer pad with a low thermal expansion coefficient has a smaller shrinkage, maintaining an effective support thickness and offsetting the gap caused by metal shrinkage, thus maintaining a tight fit and radial support between the bushing and the inner wall of the lens barrel throughout the process.

[0033] The above technical solution utilizes the differential thermal expansion characteristics of the two materials to offset the changes in the fit gap between the bushing and the lens barrel over a wide temperature range, suppressing the radial runout of the bushing and the eccentricity of the optical axis caused by temperature changes, thereby further improving the temperature adaptability and optical stability of the lens.

[0034] VI. Working Principle of Continuous Zoom Drive Among them: the adjustment drive component 12 outputs rotational driving force, which drives the cam guide pin 9 of the zoom mechanism and the compensation mechanism to move circumferentially along the zoom curve groove 11 and the compensation curve groove 14 respectively. Under the axial limiting action of the guide vertical groove 10, the cam guide pin 9 converts the circumferential motion into axial displacement, and synchronously drives the zoom slide 4 and the compensation slide 5 to move linearly along the optical axis.

[0035] In specific application scenarios, during zoom operation, the external control signal drives the adjustment drive component 12 to rotate. The adjustment drive component 12 drives the cam transmission ring on the outside of the lens barrel to rotate circumferentially. The cam guide pin 9 is constrained by the curve trajectory of the zoom curve groove 11 and the compensation curve groove 14. While moving circumferentially along the groove with the transmission ring, the circumferential rotational motion is decomposed into axial linear displacement under the circumferential limiting action of the guide vertical groove 10. The cam guide pin 9 synchronously drives the zoom slide 4 and the compensation slide 5 to move back and forth along the optical axis, continuously changing the axial distance between each lens group, realizing continuous stepless zoom from the wide-angle end to the telephoto end. At the same time, the compensation lens group synchronously shifts to correct the image plane position, maintaining clear imaging throughout the zoom range.

[0036] The above technical solution converts rotational motion into precise axial linear motion through a cam transmission mechanism, achieving continuous and smooth zoom adjustment and ensuring the stability and continuity of image quality during zooming.

[0037] VII. Wide Temperature Range Adaptive Overall Working Mechanism Specifically: Under normal temperature conditions, the preload of the elastic element 905 maintains the fit between the cam guide pin 9 and the groove wall, and the two layers of buffer pads of the adaptive fitting element 7 provide radial support. Under high temperature conditions, the thermal expansion material block 906 expands and pushes the guide pin spindle 901 outward. The buffer pad with a high thermal expansion coefficient in the adaptive fitting element 7 supplements the radial gap. Under low temperature conditions, the elastic element 905 continuously provides preload, and the buffer pad with a low thermal expansion coefficient in the adaptive fitting element 7 maintains radial support.

[0038] In specific application scenarios, when the lens operates in a normal temperature environment, the elastic element 905 provides the basic preload of the cam drive pair, eliminating transmission backlash. The two layers of buffer pads of the adaptive fitting element 7 jointly provide radial support for the guide pair, ensuring smooth zoom movement without jamming. When the lens operates in a high temperature environment, the metal components expand due to heat, causing the fit clearance to increase. At this time, the thermal expansion material block 906 expands due to heat to supplement the preload of the cam pair, and the high thermal expansion coefficient buffer pad expands synchronously to supplement the radial clearance of the guide pair, avoiding loosening of the fit and optical axis misalignment caused by high temperature expansion. When the lens operates in a low temperature environment, the metal components shrink, which can easily lead to excessive tightness or jamming. At this time, the elastic element 905 continuously maintains the preload of the cam pair, and the low thermal expansion coefficient buffer pad maintains effective support and reasonable fit clearance of the guide pair, avoiding movement jamming caused by low temperature contraction. Throughout the entire temperature range, the adaptive structure of the cam guide pin and the adaptive structure of the bushing fit work together to ensure the zoom movement accuracy and optical coaxiality throughout the entire process.

[0039] By adopting the above technical solution, the lens can achieve gapless transmission and high-precision guidance over a wide temperature range, avoiding problems such as motion backlash, jamming, and optical axis misalignment in high and low temperature environments, and significantly improving the environmental adaptability and operational reliability of the infrared zoom lens.

[0040] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Contents not described in detail in this specification belong to the prior art known to those skilled in the art. In addition, the directional terms such as up, down, left, right, front, and back in the text only represent their relative positions and not absolute positions.

[0041] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0042] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An infrared continuous zoom lens with a temperature adaptive structure, comprising a coaxially connected objective lens end fixing member (1), a zoom component assembly fixing member (2), and an eyepiece end fixing member (3), wherein the zoom component assembly fixing member (2) has a zoom mechanism and a compensation mechanism in its inner cavity and an adjustment drive member (12) on its outer side, characterized in that: The zoom mechanism includes a zoom slide (4), a radial guide bushing (6), and a cam guide pin (9). The zoom slide (4) is slidably disposed inside the radial guide bushing (6). A guide vertical groove (10) is provided on the side wall of the radial guide bushing (6). A zoom curved groove (11) is provided on the side wall of the zoom assembly fixing part (2). The cam guide pin component (9) includes a guide pin spindle (901), a tapered bushing (902), an elastic element (905), and a thermal expansion material block (906). The inner end of the guide pin spindle (901) is inserted into the guide pin mounting blind hole (41) opened on the side of the variable slide block (4). The elastic element (905) is connected between the guide pin mounting blind hole (41) and the guide pin spindle (901). The tapered bushing (902) is sleeved on the outer side of the guide pin spindle (901). The thermal expansion material block (906) is installed at the bottom of the guide pin mounting blind hole (41).

2. The infrared continuous zoom lens with temperature adaptive structure according to claim 1, characterized in that: The guide pin spindle (901) has a central retaining ring (904) integrally provided in the middle and an end protrusion ring (903) integrally provided at the outer end. The tapered bushing (902) is coaxially sleeved on the outside of the guide pin spindle (901), and its inner end abuts against the central retaining ring (904). The outer surface of the tapered bushing (902) has a tapered inclined structure that is narrow on the outside and wide on the inside.

3. The infrared continuous zoom lens with temperature adaptive structure according to claim 2, characterized in that: The elastic element (905) is coaxially sleeved on the outside of the guide pin spindle (901), and the two ends of the elastic element (905) respectively abut against the inner end face of the end protrusion ring (903) and the port side wall of the guide pin mounting blind hole (41).

4. The infrared continuous zoom lens with temperature adaptive structure according to claim 1, characterized in that: The variable sliding block (4) has fitting washers (8) fixed at both the upper and lower ends of its outer side. The outer circular surface of the fitting washers (8) slides against the inner wall of the radial guide bushing (6).

5. The infrared continuous zoom lens with temperature adaptive structure according to claim 1, characterized in that: An adaptive fitting element (7) is provided on the outer side of the radial guide bushing (6), and the outer side of the adaptive fitting element (7) is fitted with the inner wall of the zoom component assembly fastener (2).

6. The infrared continuous zoom lens with a temperature adaptive structure according to claim 5, characterized in that: The adaptive fitting component (7) includes a fixed ring (701), a first fitting buffer pad (702) and a second fitting buffer pad (703). The fixed ring (701) is coaxially fixed to the outer wall of the radial guide bushing (6). The first fitting buffer pad (702) and the second fitting buffer pad (703) are stacked on the inner side of the fixed ring (701) and are made of materials with different coefficients of thermal expansion.

7. The infrared continuous zoom lens with temperature adaptive structure according to claim 1, characterized in that: The compensation mechanism includes a compensation slide (5), a compensation group guide bushing (13), and a compensation curve groove (14). The compensation slide (5) is slidably disposed inside the compensation group guide bushing (13), and the compensation curve groove (14) is opened on the upper side wall of the variable magnification component assembly fixture (2).

8. The infrared continuous zoom lens with a temperature adaptive structure according to claim 7, characterized in that: The side wall of the compensation group guide bushing (13) is provided with a guide vertical groove (10), and the cam guide pin (9) passes through the compensation curve groove (14) and the guide vertical groove (10), with its inner end connected to the side wall of the compensation slide (5).

9. The infrared continuous zoom lens with a temperature adaptive structure according to claim 7, characterized in that: An adaptive fitting element (7) is provided on the outer side of the compensation group guide bushing (13), and a fitting washer (8) is provided between the compensation slide (5) and the compensation group guide bushing (13).

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