Airborne infrared continuous zoom lens and method of assembling the same

Abstract

The application discloses an airborne infrared continuous zoom lens and an assembling method thereof, and relates to the technical field of zoom lenses.The airborne infrared continuous zoom lens comprises an optical-mechanical platform, an optical system, a zoom assembly and a focusing group; the optical system is arranged in the optical-mechanical platform and is drivenly connected with the zoom driving assembly and the focusing driving assembly; the optical system comprises, in sequence from an object end to an image end, a front fixed group of lenses, a zoom group of lenses, a first compensation group of lenses, a second compensation group of lenses, a first focusing lens and a second focusing lens; the front fixed group of lenses is made of Ge material; the zoom group of lenses is made of Ge material; the first compensation group of lenses is made of Si material; the second compensation group of lenses is made of Si material; the first focusing lens is made of Ge material; and the second focusing lens is made of Ge material. The lens has the performances of high imaging quality, high spatial resolution, compact structure, short zooming and compensation stroke, long detection distance, light weight, vibration resistance and impact resistance.

Description

Technical Field

[0001] This application relates to the field of zoom lens technology, and in particular to an airborne infrared continuous zoom lens and its assembly method. Background Technology

[0002] With the continuous development and maturation of drone technology, drones have been widely used in industrial applications such as aerial photography, remote sensing and mapping, forest fire prevention, power line inspection, search and rescue, etc. To achieve these functions, it is often necessary to install infrared continuous zoom lenses on drones for observation and search. Existing infrared continuous zoom lenses mounted on drones are heavy and bulky. Adding such lenses results in excessive weight and burden on the drone; currently, the main solution is to increase the size of the drone body to accommodate them.

[0003] However, increasing the size of the drone reduces its flight controllability, and the flight maneuverability of the drone affects the clarity of the acquired images. Drones cannot be made lightweight or miniaturized.

[0004] For example, CN201820533811.1 discloses a fire emergency evacuation drone. This structure uses a projection lamp and an infrared zoom camera mounted side by side on the bottom of the drone body to obtain real-time information on the location of trapped personnel in a fire environment. However, the lens used is a commonly used lens in this field, resulting in a large overall structure of the device, and the lens cannot achieve continuous zoom.

[0005] The information disclosed in the background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] This application provides an airborne infrared continuous zoom lens and its assembly method. The lens features smooth transmission, compact structure, easy assembly, high optical axis consistency and air gap accuracy, and high imaging quality, high spatial resolution, compact structure, short zoom and compensation stroke, long detection distance, light weight, and resistance to vibration and shock.

[0007] This application provides an airborne infrared continuous zoom lens, including: an optical-mechanical platform, an optical system, a zoom drive assembly, and a focus drive assembly; the optical system, the zoom drive assembly, and the focus drive assembly are housed within the optical-mechanical platform. The optical system includes the following components connected sequentially from the object end to the eye end: a front fixed lens group, a zoom lens group, a first compensation lens group, a second compensation lens group, a first focusing lens, and a second focusing lens. The zoom lens group, the first compensation lens group, and the second compensation lens group are respectively driven and connected to the zoom drive assembly; The first focusing lens and the second focusing lens are respectively driven and connected to the focusing drive assembly; The front fixed lens group is made of Ge material; the zoom lens group is made of Ge material; the first compensation lens group is made of Si material; the second compensation lens group is made of Si material; the first focusing lens is made of Ge material; and the second focusing lens is made of Ge material.

[0008] Preferably, a first air gap of 5-25mm is provided between the front fixed lens group and the zoom lens group; a second air gap of 1-20mm is provided between the zoom lens group and the first compensation lens group; a third air gap of 1-5mm is provided between the first compensation lens group and the second compensation lens group; a fourth air gap of 4-18mm is provided between the second compensation lens group and the first focusing lens; a fifth air gap of 10mm is provided between the first focusing lens and the second focusing lens group; and a sixth air gap of 5-8mm is provided between the second focusing lens and the rear end.

[0009] Preferably, the maximum axial movement of the first focusing lens and the second focusing lens is 5-8 mm.

[0010] Preferably, the optical engine platform includes: a first mounting end plate, a second mounting end plate, and multiple connecting rods; the multiple connecting rods are connected at intervals to the periphery of the opposite surfaces of the first mounting end plate and the second mounting end plate; the space enclosed by the first mounting end plate, the second mounting end plate, and the multiple connecting rods accommodates a zoom group, a first compensation group, a second compensation group, and a focusing group and their driving components; the front fixed lens group is mounted in the end face of the first mounting end plate.

[0011] Preferably, the connecting rod includes: a first connecting rod, a second connecting rod, a third connecting rod, a fourth connecting rod, a first protective rod, and a second protective rod; the zoom group, the first compensation group, the second compensation group, and the focusing group are accommodated within the space enclosed by the first connecting rod, the second connecting rod, the third connecting rod, the fourth connecting rod, the first mounting end plate, and the second mounting end plate; The drive assembly is installed within the space enclosed by the first protective rod, the second protective rod, the first mounting end plate, and the second mounting end plate.

[0012] Preferably, it includes: a zoom lens frame, a first compensation lens frame, and a second compensation lens frame; The zoom lens group is glued to the zoom lens frame and is driven to connect to the zoom drive assembly through the zoom lens frame; The first compensation lens group is bonded to the first compensation frame and is driven to the zoom drive assembly through the first compensation frame. The second compensation lens group is bonded to the second compensation frame and is driven to the zoom drive assembly through the second compensation frame.

[0013] Preferably, the bonding areas of the variable magnification lens group to the frame, the bonding areas of the first compensation lens group to the frame, and the bonding areas of the second compensation lens group to the frame are all set according to the calculation results of the following formula: In the above formula, W represents the weight of the eyeglass frame. Acceleration under harsh conditions; is the safety factor; J is the tensile or shear strength of the adhesive.

[0014] Preferably, the zoom drive assembly includes: a cam rod and a zoom motor; the cam rod and the zoom motor are driven together; the cam rod is provided with a zoom guide groove and a first compensation guide groove and a second compensation guide groove separately at circumferential angles; a guide rod is provided on one side of the zoom lens frame, and the guide rod moves along the zoom guide groove; a guide rod is provided on one side of the first compensation lens frame, and the guide rod moves along the first compensation guide groove; a guide rod is provided on one side of the second compensation lens frame, and the guide rod moves along the first compensation guide groove to form the second compensation guide groove.

[0015] Preferably, the zoom drive assembly includes: a linear guide rail and a slider; the slider is slidably disposed along the linear guide rail; one side of the zoom lens frame is connected to the slider; one side of the first compensation lens frame is connected to the slider; one side of the second compensation lens frame is connected to the slider; the zoom drive assembly includes: a first spring group, a second spring group, and a third spring group; a connecting block is disposed on one side of the zoom lens frame, the connecting block is sleeved on the guide rod of the first spring group, and the two ends of the springs of the first spring group are elastically connected to the connecting block and the optical engine platform, respectively; A connecting block is provided on one side of the first compensation lens frame. The connecting block is sleeved on the guide rod of the second spring group. The two ends of the springs of the second spring group are elastically connected to the connecting block and the optical engine platform, respectively. A connecting block is provided on one side of the second compensation frame. The connecting block is sleeved on the guide rod of the third spring group. The two ends of the spring of the third spring group are elastically connected to the connecting block and the optical engine platform, respectively.

[0016] Another aspect of this application provides an airborne infrared continuous zoom lens assembly method as described above, comprising the following steps: an optical system is respectively installed in a zoom drive assembly and a focus drive assembly; the zoom drive assembly and the focus drive assembly are installed in an optomechanical platform.

[0017] The beneficial effects that this application can produce include: 1) The airborne infrared continuous zoom lens provided in this application has a smooth transmission, compact structure, easy assembly, high optical axis consistency and air gap accuracy, high imaging quality and high spatial resolution performance, compact structure, short zoom and compensation stroke, long detection distance, and is also lightweight and resistant to vibration and shock, and has good application prospects.

[0018] 2) The airborne infrared continuous zoom lens provided in this application achieves high imaging quality, compact structure, and short zoom compensation travel. This lens structure effectively improves the stability of the lens frame movement and its resistance to vibration and shock during use, while also facilitating the adjustment of the air gap in the optical system.

[0019] 3) The airborne infrared continuous zoom lens provided in this application improves the uniformity of force on the zoom lens group by setting corresponding spring components for each zoom lens group, and enhances the stability of the zoom lens group movement in the optical axis direction. This is beneficial for obtaining clear images during UAV flight or hovering, improving image clarity, and at the same time improving the lens's resistance to impact and vibration to ensure the air gap between optical elements.

[0020] 4) The airborne infrared continuous zoom lens provided in this application uses an integrated optical-mechanical platform, which effectively reduces the overall weight of the lens and makes the structure compact. Compared with existing infrared continuous zoom lenses, the overall volume is reduced by 23% and the weight is reduced by 31%.

[0021] 5) The airborne infrared continuous zoom lens provided in this application, with its slider and linear guide rail in the lens structure, ensures air gap between lenses, achieving excellent image quality across the entire focal length range during drone-borne cruise. The use of adhesive bonding between the lens and the frame enables stress-free assembly, allowing the optical system to be adjusted to its optimal operating state, effectively improving image clarity and target positioning accuracy when mounted on a drone. Attached Figure Description

[0022] Figure 1 A schematic diagram of the optical system for the airborne infrared continuous zoom lens provided in this application; Figure 2 A schematic diagram of the axial side of the airborne infrared continuous zoom lens provided in this application; Figure 3 Right side view of the airborne infrared continuous zoom lens provided in this application; Figure 4 for Figure 3 A schematic diagram of the AA-direction cross-section structure; Figure 5 for Figure 3 Schematic diagram of the BB-direction cross-section structure; Figure 6 A schematic diagram of the optical-mechanical platform provided in the application; Figure 7 A three-dimensional structural diagram of the airborne infrared continuous zoom lens provided in this application; Figure 8 This is a three-dimensional structural diagram of the camshaft provided in this application; Figure 9An image showing the imaging effect of a lens with a focal length of 15mm in at least one embodiment provided in this application; Figure 10 An image showing the imaging effect when the lens focal length reaches 90mm in at least one embodiment provided in this application.

[0023] Legend: 1. Objective lens retaining ring; 2. Optical engine platform; 21. Motor mounting hole; 22. Lens mounting hole; 23. Connecting rod; 24. Mounting end plate; 3. Circuit board; 4. Zoom lens frame; 5. First compensation lens frame; 6. Second compensation lens frame; 7. Focusing assembly; 10. Focusing motor; 11. Zoom motor; 12. Slider; 13. Linear guide rail; 15. Cam rod; 16. Bearing; 18. First spring assembly; 19. Second spring assembly; 20. Third spring assembly; 211. First connecting rod; 212. Second connecting rod; 213. Third connecting rod; 214. Fourth connecting rod; 221. First retaining ring; 222. Second protective rod; 241. First mounting end plate; 242. Second mounting end plate; 151. Magnification guide groove; 152. First compensation guide groove; 153. Second compensation guide groove; 301. Front fixed lens group; 302. First air gap; 303. Magnification lens group; 304. Second air gap; 305. First compensation lens group; 306. Third air gap; 307. Second compensation lens group; 308. Fourth air gap; 309. First focusing lens; 310. Fifth air gap; 311. Second focusing lens; 312. Sixth air gap. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0026] Technical means not detailed in this application and not used to solve the technical problems of this application are all set according to common general knowledge in the field, and multiple common general knowledge setting methods can be implemented.

[0027] See Figures 1-9The airborne infrared continuous zoom lens provided in this application includes: an optical-mechanical platform 2, an optical system, a zoom drive assembly, and a focus drive assembly; the optical system is disposed in the optical-mechanical platform 2 and is driven and connected to the zoom drive assembly and the focus drive assembly respectively. The optical system provided in this application has the following lens materials arranged along the light incident direction from the object end to the eye end: front fixed group lens 301, zoom group lens 303, first compensation group lens 305, second compensation group lens 307, first focusing lens 309, and second focusing lens 311.

[0028] The front fixed lens group 301 is made of Ge material; the zoom lens group 303 is made of Ge material; the first compensation lens group 305 is made of Si material; the second compensation lens group 307 is made of Si material; the first focusing lens 309 is made of Ge material; and the second focusing lens 311 is made of Ge material.

[0029] A first air gap 302 of 5-25mm is provided between the front fixed lens group 301 and the zoom lens group 303; a second air gap 304 of 1-20mm is provided between the zoom lens group 303 and the first compensation lens group 305; a third air gap 306 of 1-5mm is provided between the first compensation lens group 305 and the second compensation lens group 307; a fourth air gap 308 of 4-18mm is provided between the second compensation lens group 307 and the first focusing lens 309; a fifth air gap 310 of 10mm is provided between the first focusing lens 309 and the second focusing lens 311; and a sixth air gap 312 is provided between the rear end of the second focusing lens 311 and the imaging end. The specific location of the rear end of the second focusing lens 311 is shown in [reference needed]. Figure 1 As shown, a sixth air gap 312 of 5-8mm is provided between the rear end of the second focusing lens 311 and the imaging end.

[0030] The optical system obtained by combining the above lenses achieves the following optical properties: (1) Focal length: f=15~260mm, zoom ratio up to 17 times; (2) Field of view range: 30.22°×24.09°~2.2°×1.9°; (3) Relative aperture: 7.8 mm; (4) Detector compatibility: Compatible with cooled mid-wave infrared detectors with a target area of ​​640*512 and a pixel size of 15μm; (5) Operating temperature: -40℃~+60℃; (6) Applicable spectral range: 3μm~5μm.

[0031] This optical system fully considers the impact of temperature changes on the system. By rationally selecting lens materials, it effectively ensures stable imaging performance during long-term flight, avoiding the degradation of image quality caused by increased incident light intensity at higher altitudes. Simultaneously, multiple lenses made of Ge material correct chromatic aberration, preventing image quality deterioration due to prolonged use. This optical system, while maintaining imaging quality, helps reduce overall weight. It effectively balances system aberrations, resulting in a simpler optical system structure and better image quality.

[0032] The optical platform 2 includes: a front fixed group, a zoom group, a first compensation group, a second compensation group, and a focusing group, which are connected sequentially from the object end to the eye end along the incident direction of light.

[0033] The front fixation group includes: objective lens retaining ring 1 and front fixation group lens 301; the front fixation group lens 301 is housed in the end face of the optical engine platform 2, and the objective lens retaining ring 1 is pressed against the front end of the front fixation group lens 301.

[0034] The zoom group includes: a zoom lens 303, a zoom frame 4, and a zoom retaining ring. The zoom frame 4 is housed in the middle of the optical engine platform 2. The zoom lens 303 is installed inside the zoom frame 4 and bonded to the zoom frame 4. The zoom retaining ring is pressed onto the end face to secure the zoom lens 303. The side wall of the first compensation frame 5 is connected to the first spring assembly 18 via a connecting block. The first spring assembly 18 is housed inside the optical engine platform 2. In one specific embodiment, the adhesive material between the zoom lens 303 and the zoom frame 4 is optical epoxy.

[0035] The first compensation group includes: a first compensation group lens 305, a first compensation frame 5, and a first compensation group retaining ring. The first compensation group lens 305 is accommodated in the end face groove of the first compensation frame 5 and bonded to the first compensation frame 5. The first compensation group retaining ring is pressed onto the outer end face of the first compensation group lens 305, and the first compensation group retaining ring is snapped into the first compensation frame 5 to achieve fixed installation of the first compensation group lens 305 within the first compensation frame 5. A connecting block is provided on the outer side wall of the first compensation frame 5 to slide and connect with the optical engine platform 2. In a specific embodiment, the adhesive material for the first compensation group lens 305 and the first compensation frame 5 is optical epoxy.

[0036] The second compensation group includes: a second compensation group lens 307, a second compensation frame 6, and a second compensation group retaining ring. The second compensation group lens 307 is accommodated within a groove on the end face of the second compensation frame 6 and bonded to the second compensation frame 6. The second compensation group retaining ring is pressed onto the outer end face of the second compensation group lens 307 and snapped into the second compensation frame 6, thus achieving the installation and fixation of the second compensation group lens 307 within the second compensation frame 6. In one specific embodiment, the second compensation group lens 307 and the second compensation frame 6 are bonded together with optical epoxy adhesive.

[0037] In one specific embodiment, the bonding areas of the zoom lens group 303, the zoom frame 4, the first compensation lens group 305, the first compensation frame 5, the second compensation lens group 307, and the second compensation frame 6 are set according to the calculation results of the following formula: In the above formula, W represents the weight of the eyeglass frame. Acceleration under harsh conditions; J represents the safety factor; J is the tensile or shear strength of the adhesive. The minimum bonding area calculated using the previous formula is the minimum bonding area. Setting the bonding area accordingly can reduce the adverse effects of bonding on optical imaging performance. The resulting optical system is suitable for use on UAVs, preventing lens movement within the lens frame and improving the lens's resistance to impact, thereby ensuring imaging quality during flight.

[0038] The size of the adhesive groove is designed according to the minimum bonding area. Adhesive is injected into the adhesive groove, which on the one hand achieves radial constraint on the optical lens and provides reliability; on the other hand, since the lens and the frame are in a clearance fit, the adhesive between the two greatly improves the vibration and shock resistance of the infrared continuous zoom lens.

[0039] The focusing group is located inside the second eyepiece of the optical platform.

[0040] The following describes the connection method between the zoom group, the first compensation group, the second compensation group, and the optical engine platform 2: The output shaft of the variable motor 11 is provided with a motor gear that meshes with a gear provided on the cam rod 15. The gear assembly can be set in a manner commonly used in the art, which will not be described in detail here.

[0041] The cam rod 15 has a zoom guide groove 151, a first compensation guide groove 152, and a second compensation guide groove 153 arranged circumferentially on its surface. Guide rods are installed on the outer sides of the lens frames of the zoom group, the first compensation group, and the second compensation group. Bearings 16 are fitted onto these guide rods. The guide rods of each group are inserted into their corresponding grooves, and the bearings 16 are accommodated within their respective grooves. The bearings 16 on the zoom group are driven to connect with the zoom guide groove 151 located on the front side of the cam rod 15. The bearings 16 on the first compensation group are driven to connect with the first compensation guide groove 152 located in the middle of the cam rod 15. The bearings 16 on the second compensation group are driven to connect with the second compensation guide groove 153 located on the rear side of the cam rod 15. Since the connection method between the cam rod 15 and each bearing 16 is set in a manner commonly used in the art, and the setting method of each bearing 16 is the same, they are not numbered and described separately here.

[0042] During the rotation of the cam rod 15, when the zoom group, the second compensation group or the third compensation group moves to the extreme positions at both ends, the extreme positions of the movement are controlled by the circuit board 3 set on the optical-mechanical platform 2.

[0043] After the zoom motor 11 is driven and connected to the cam rod 15, the cam rod 15 rotates and drives the zoom group connected to the cam rod 15. The first compensation group and the second compensation group move back and forth in the optical engine platform 2 along the optical axis.

[0044] The linear guide rail 13 is set inside the optical engine platform 2, and the slider 12 is slidably set on the linear guide rail 13. The lens frames of the zoom group, the second compensation group or the third compensation group are respectively connected to the slider 12.

[0045] In one specific embodiment, the outer sides of the zoom lens frame 4, the first compensation lens frame 5, and the second compensation lens frame 6 are respectively connected to the slider 12.

[0046] After the focusing motor 10 drives the cam rod 15 to rotate, the cam rod 15 drives the zoom group, the first compensation group, and the second compensation group to move along the optical axis on the optomechanical platform 2. The guide force provided by the slider 12 and the linear guide rail 13 can achieve smooth movement with low friction, resulting in stable zoom, high rigidity, impact resistance, and high axial and radial positioning accuracy. It is especially suitable for image acquisition in UAV flight environments.

[0047] The focusing motor 10 is housed within the optical engine platform 2, with one end of the focusing motor 10 mounted in the motor mounting hole 21 of the optical engine platform 2 via a mounting bracket. The zoom motor 11 is mounted on the underside of the optical engine platform 2 via a mounting bracket.

[0048] The focusing assembly includes: a first focusing lens 309, a second focusing lens 311, a focusing guide tube, and a focusing lens frame. The focusing lens frames are arranged in pairs within the first and second ends of the focusing guide tube and are threadedly connected to the inner wall of the focusing guide tube. The first focusing lens 309 and the second focusing lens 311 are respectively housed within the focusing lens frames. Rotation of the focusing guide tube causes the focusing lens frames to move the first focusing lens 309 and the second focusing lens 311 back and forth. The focusing guide tube is installed within the lens mounting hole 22 on the end face of the optical engine platform 2. Two circumferentially extending, 90° straight inclined grooves, known as focusing slots, are provided on the inner wall of the focusing guide tube; these slots are arranged in an envelope pattern. Guide pins are symmetrically arranged on the outer wall of each focusing lens frame; these guide pins engage with the focusing slots and move along them.

[0049] A gear on the drive shaft of the focusing motor 10 meshes with a drive gear on the outer wall of one end of the focusing guide cylinder, causing the focusing guide cylinder to rotate. The focusing lens frames at both ends of the focusing guide cylinder move axially back and forth within the focusing guide cylinder as it rotates, achieving focusing. When the focusing guide cylinder rotates to its extreme positions at both ends, the circuit board 3 identifies and controls these extreme positions.

[0050] When the focusing motor 10 drives the focusing cylinder to rotate, the focusing cylinder transmits the motion to the focusing lens frame through the guide pin. Under the action of the guide straight groove, the focusing lens frame converts the rotational motion of the focusing cylinder into the parallel movement of the focusing cylinder along the optical axis, thereby achieving focusing.

[0051] The automatic stop of the zoom motor 11 at the telephoto and short focal length endpoints is controlled by circuit board 3, and the automatic stop of the focusing motor 10 at the forward and backward focusing endpoints is also controlled by circuit board 3. Circuit board 3 is located on the top surface of the optical engine platform 2 and is electrically connected to each control motor.

[0052] When the airborne infrared continuous zoom lens provided in this application is in use, light sequentially passes through the front fixed group lens 301, the zoom group lens 303, the first compensation group lens 305, the second compensation group lens 307, the first focusing lens 309, and the second focusing lens 311 to form an image. The zoom motor 11 drives the cam rod 15 to rotate, and then drives the zoom group, the first compensation group, and the second compensation group to move along the zoom groove on the surface of the cam rod 15 through each bearing 16, so as to realize the back-and-forth movement of the first compensation group and the second compensation group, accurately adjust the air gaps between each lens, and realize zoom.

[0053] This lens combines zoom and focus while reducing overall weight and size, achieving motorized zoom.

[0054] In one specific embodiment, the system includes: a first spring group 18, a second spring group 19, and a third spring group 20. All three spring groups are housed within the optical engine platform 2. The zoom lens frame 4 of the zoom group is connected to the first spring group 18 via a connecting block. The first compensation lens frame 5 of the first compensation group is connected to the second spring group 19 via a connecting block. The second compensation lens frame 6 of the second compensation group is connected to the third spring group 20 via a connecting block. Each of the first spring group 18, second spring group 19, and third spring group 20 is a combination of a guide rod and a spring. One end of the guide rod is connected to the optical engine platform 2, and the other end is connected to the corresponding lens frame. The spring is compressed between the corresponding lens frame and the optical engine platform 2.

[0055] During the zoom process, multiple sets of springs are set up to buffer the movement of the zoom group, the first compensation group, and the second compensation group lenses, effectively ensuring the air gap between each lens in the optical system and improving image clarity.

[0056] In one specific embodiment, to reduce overall weight, the optical engine platform 2 includes: a first mounting end plate 241, a second mounting end plate 242, and multiple connecting rods 23. The multiple connecting rods 23 are spaced apart between the first mounting end plate 241 and the second mounting end plate 242, and are respectively connected to the periphery of the first mounting end plate 241 and the second mounting end plate 242. The space enclosed by the first mounting end plate 241, the second mounting end plate 242, and the multiple connecting rods 23 houses a zoom group, a first compensation group, a second compensation group, and a focusing group, as well as their driving components. The front fixed lens group 301 is mounted within the end face of the first mounting end plate 241.

[0057] In one specific embodiment, the connecting rod 23 includes: a first connecting rod 211, a second connecting rod 212, a third connecting rod 213, a fourth connecting rod 214, a first protective rod 221, and a second protective rod 222; the area enclosed by the first connecting rod 211, the second connecting rod 212, the third connecting rod 213, the fourth connecting rod 214, the first mounting end plate 241, and the second mounting end plate 242 accommodates and sets up a zoom group, a first compensation group, a second compensation group, and a focusing group; the first protective rod 221 and the second protective rod 222 are symmetrically arranged on the lower part of the optical engine platform 2, and the cam rod 15 and the linear guide rail 13 are installed below the first protective rod 221 and the second protective rod 222.

[0058] In one specific embodiment, the focusing assembly is disposed on the end face of the mounting plate 24 of the eye end; the mounting plate 24 has a lens mounting hole 22 and a motor mounting hole 21 spaced apart; the focusing assembly is installed in the lens mounting hole 22.

[0059] In one specific embodiment, the optomechanical platform 2 adopts an integrated structure. By using topology optimization and size optimization, the traditional cam cylinder structure is simplified. The integrated optomechanical platform 2 frame has good structural consistency, high weight reduction rate, and good mechanical and thermal stability. It solves the technical problems of poor mechanical performance, low weight reduction rate, and difficulty in ensuring thermal stability of combined structures. The overall weight reduction rate is high, the mechanical and thermal stability is good, and the assembly process is good. It is easy to assemble, adjust and test, and it is convenient to adjust the air gap in the optical system.

[0060] In one specific embodiment, the frames are all designed to be lightweight. By using topology optimization and size optimization, the traditional optical-mechanical platform 2 structure is simplified, greatly reducing volume and weight, and making it easy to assemble, adjust and test.

[0061] To achieve the effect of being lightweight and high-strength, all components are made of magnesium-aluminum alloy.

[0062] Another aspect of this application provides an airborne infrared continuous zoom lens assembly method as described above, comprising the following steps: the optical system is respectively installed in the zoom drive assembly and the focus drive assembly; the zoom drive assembly and the focus drive assembly are installed in the optomechanical platform 2.

[0063] When the lens provided in this application is mounted on a drone, the imaging effect at a focal length of 15mm is shown in the image. Figure 9 After zooming, the image quality at a focal length of 90mm is as follows: Figure 10 As shown in the comparison, the lens provided in this application can reliably zoom during drone flight, with good imaging effect. Weighing the lens reveals that its overall weight is only 200g. Compared to existing continuous zoom lenses, the lens provided in this application has a smaller overall size and lower weight, effectively reducing overall mass and volume.

[0064] Although this application 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 this application should be included within the protection scope of this application.

Claims

1. An airborne infrared continuous zoom lens, characterized in that, include: Optical platform (2), optical system, zoom drive assembly and focus drive assembly; The optical system, zoom drive assembly, and focus drive assembly are housed within the optomechanical platform (2); The optical system includes the following components connected in sequence from the object end to the eye end: front fixed lens group (301), zoom lens group (303), first compensation lens group (305), second compensation lens group (307), first focusing lens (309), and second focusing lens (311). The zoom lens group (303), the first compensation lens group (305), and the second compensation lens group (307) are respectively driven and connected to the zoom drive assembly; The first focusing lens (309) and the second focusing lens (311) are respectively driven and connected to the focusing drive assembly; The front fixed lens group (301) is made of Ge material; the zoom lens group (303) is made of Ge material; the first compensation lens group (305) is made of Si material; the second compensation lens group (307) is made of Si material; the first focusing lens (309) is made of Ge material; and the second focusing lens (311) is made of Ge material. A first air gap (302) of 5-25mm is provided between the front fixed lens group (301) and the zoom lens group (303); a second air gap (304) of 1-20mm is provided between the zoom lens group (303) and the first compensation lens group (305); a third air gap (306) of 1-5mm is provided between the first compensation lens group (305) and the second compensation lens group (307); a fourth air gap (308) of 4-18mm is provided between the second compensation lens group (307) and the first focusing lens (309); a fifth air gap (310) of 10mm is provided between the first focusing lens (309) and the second focusing lens (311); and a sixth air gap (312) of 5-8mm is provided between the rear end of the second focusing lens (311) and the imaging end. The maximum axial movement of the first focusing lens (309) and the second focusing lens (311) is 5-8 mm.

2. The airborne infrared continuous zoom lens according to claim 1, characterized in that, The optical platform (2) includes: a first mounting end plate (241), a second mounting end plate (242), and multiple connecting rods (23); the multiple connecting rods (23) are connected at intervals to the periphery of the opposite surfaces of the first mounting end plate (241) and the second mounting end plate (242); the space enclosed by the first mounting end plate (241), the second mounting end plate (242), and the multiple connecting rods (23) accommodates a zoom group, a first compensation group, a second compensation group, and a focusing group and their driving components; the front fixed lens group (301) is installed in the end face of the first mounting end plate (241).

3. The airborne infrared continuous zoom lens according to claim 2, characterized in that, The connecting rod (23) includes: a first connecting rod (211), a second connecting rod (212), a third connecting rod (213), a fourth connecting rod (214), a first protective rod (221), and a second protective rod (222); the zoom group, the first compensation group, the second compensation group, and the focusing group are housed within the space enclosed by the first connecting rod (211), the second connecting rod (212), the third connecting rod (213), the fourth connecting rod (214), the first mounting end plate (241), and the second mounting end plate (242); The drive assembly is installed in the space enclosed by the first protective rod (221), the second protective rod (222), the first mounting end plate (241), and the second mounting end plate (242).

4. The airborne infrared continuous zoom lens according to claim 1, characterized in that, include: Variable magnification frame (4), first compensation frame (5), second compensation frame (6); The zoom lens group (303) is glued to the zoom lens frame (4) and is driven to the zoom drive assembly through the zoom lens frame (4); The first compensation lens (305) is bonded to the first compensation frame (5) and is driven to the zoom drive assembly through the first compensation frame (5); The second compensation lens (307) is bonded to the second compensation frame (6) and is driven to the zoom drive assembly through the second compensation frame (6).

5. The airborne infrared continuous zoom lens according to claim 4, characterized in that, The bonding area between the variable magnification lens group (303) and the frame, the bonding area between the first compensation lens group (305) and the frame, and the bonding area between the second compensation lens group (307) and the frame are all set according to the calculation results of the following formula: In the above formula, W is the weight of the frame, α g Acceleration under harsh conditions; f s is the safety factor; J is the tensile or shear strength of the binder.

6. The airborne infrared continuous zoom lens according to claim 4, characterized in that, The zoom drive assembly includes: a cam rod (15) and a zoom motor (11); the cam rod (15) and the zoom motor (11) are driven together; the cam rod is provided with a zoom guide groove (151) and a first compensation guide groove (152) and a second compensation guide groove (153) at circumferential angles; a guide rod is provided on one side of the zoom lens frame (4), and the guide rod moves along the zoom guide groove (151); a guide rod is provided on one side of the first compensation lens frame (5), and the guide rod moves along the first compensation guide groove (152); a guide rod is provided on one side of the second compensation lens frame (6), and the guide rod moves along the second compensation guide groove (153).

7. The airborne infrared continuous zoom lens according to claim 6, characterized in that, The zoom drive assembly includes: a linear guide rail (13) and a slider (12); the slider (12) is slidably positioned along the linear guide rail (13); one side of the zoom lens frame (4) is connected to the slider (12); one side of the first compensation lens frame (5) is connected to the slider (12); one side of the second compensation lens frame (6) is connected to the slider (12); The zoom drive assembly includes: a first spring group (18), a second spring group (19), and a third spring group (20); a connecting block is provided on one side of the zoom lens frame (4), the connecting block is sleeved on the guide rod of the first spring group (18), and the two ends of the springs of the first spring group (18) are elastically connected to the connecting block and the optical engine platform (2) respectively; A connecting block is provided on one side of the first compensating frame (5). The connecting block is sleeved on the guide rod of the second spring group (19). The two ends of the springs of the second spring group (19) are elastically connected to the connecting block and the optical platform (2) respectively. A connecting block is provided on one side of the second compensating frame (6). The connecting block is sleeved on the guide rod of the third spring group (20). The two ends of the springs of the third spring group (20) are elastically connected to the connecting block and the optical platform (2) respectively.

8. A method for assembling an airborne infrared continuous zoom lens as described in any one of claims 1 to 7, characterized in that, Includes the following steps: The optical systems are respectively installed in the zoom drive assembly and the focus drive assembly; The zoom drive assembly and the focus drive assembly are installed in the optical engine platform (2).

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