Optical lens system

Abstract

This invention discloses an optical lens system comprising multiple lens groups forming an optical axis. Each lens group includes a telescope lens group, a scanning galvanometer, an aperture stop, a front objective lens group, a rear objective lens group, and an image plane, arranged sequentially from the object side to the image side. The optical lens system operates in two bands: a conventional visible light continuous zoom band of 486–656 nm and a fog-penetrating band of 850–950 nm, enabling observation even in foggy conditions during the day. The zoom ratio Γ of the optical lens system is set to a range of 1 < Γ ≤ 5, and the F-number is set to 4.0, achieving a pixel size of 3.5 μm and a corresponding optical field of view coverage from 1.92° × 1.08° to 9.6° × 5.41°. This addresses the problem of out-of-focus image points in existing optical lens systems, which prevents clear imaging in poor visibility conditions.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and more particularly to optical lens systems. Background Technology

[0002] With the rapid development of modern technology, visible light zoom optical systems are increasingly used to adapt to target detection and monitoring in various fields such as land, sea, and air. They can quickly aim and clearly image targets at different positions and distances, and have become an integral part of modern weaponry. Equipped with a rotating gimbal, these systems perform 360° circumferential scanning or scanning within a specific angular range to quickly detect targets. After target detection, the system switches to a staring tracking mode. This gives the visible light zoom optical system both search and tracking modes, greatly improving its ability to detect threatening targets.

[0003] Existing technology centers generally lack the ability to scan and search for targets without a large field of view, possessing only staring tracking capabilities. Furthermore, the addition of a scanning galvanometer in the converging optical path of the objective lens group causes defocusing of off-axis field-of-view images, making it difficult to guarantee image quality and increasing design complexity. Due to limitations in the operating wavelength, existing zoom optical systems can only operate in good visibility conditions; in adverse environments with severe smoke, fog, or haze, clear imaging is impossible. Moreover, to reduce the design complexity of zoom lenses, large F-numbers (F≥5) are generally used, resulting in reduced system resolution; or variable F-number designs reduce the consistency of resolution across different focal lengths, leading to performance deviations when transitioning from short focal lengths to long focal lengths. Summary of the Invention

[0004] The main objective of this invention is to propose an optical lens system that addresses the problem of out-of-focus image points in existing optical lens systems, which prevents clear imaging in poor visibility conditions.

[0005] To achieve the above objectives, the present invention proposes an optical lens system, wherein the optical lens system comprises multiple lens groups forming an optical axis. The multiple lens groups include a telescope lens group, a scanning galvanometer, an aperture stop, a front objective lens group, a rear objective lens group, and an image plane. The telescope lens group, the scanning galvanometer, the front objective lens group, the rear objective lens group, and the image plane are arranged sequentially from the object side to the image side. The aperture stop coincides with the exit pupil of the telescope lens group and is located at the scanning galvanometer.

[0006] The optical lens system is configured to operate in two bands: 486–656 nm and 850–950 nm. The zoom ratio Γ of the optical lens system is configured to range from 1 to 5. The F-number of the optical lens system is configured to be 4.0.

[0007] Optionally, the telescope system lens group includes a front fixed lens group, a zoom lens group, a compensation lens group, and a rear fixed lens group arranged sequentially from the object side to the image side. The zoom lens group and the compensation lens group can be movably arranged along the extension direction of the optical axis so that the focal length f of the optical lens system can be continuously zoomed between 40mm and 200mm.

[0008] Optionally, the front fixed lens group includes a first lens, a second lens, and a third lens arranged sequentially from the object side to the image side, wherein the first lens and the second lens are cemented together to form a first cemented lens;

[0009] The zoom lens group includes a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side. The fourth lens has a positive optical power, and the fifth lens and the sixth lens are cemented together to form a second cemented lens with a negative optical power.

[0010] The compensation lens group includes a seventh lens, an eighth lens, and a ninth lens arranged sequentially from the object side to the image side. The optical power of the seventh lens is negative, the optical power of the eighth lens is positive, and the optical power of the ninth lens is positive.

[0011] The rear fixed lens group includes a tenth lens, an eleventh lens, and a twelfth lens arranged sequentially from the object side to the image side. The tenth lens and the eleventh lens are cemented together to form a third cemented lens with negative optical power, and the twelfth lens has positive optical power.

[0012] Optionally, the first lens is a convex-concave lens, with the concave surface of the first lens facing away from the object; the second lens is a biconvex lens; and the third lens is a convex-concave lens, with the concave surface of the third lens facing away from the object.

[0013] The fourth lens is a convex-concave lens, with its concave surface facing away from the object; the fifth lens is a biconcave lens; and the sixth lens is a convex-concave lens, with its concave surface facing away from the object.

[0014] The seventh lens is a convex-concave lens, with the concave surface of the seventh lens facing away from the object; the eighth lens is a biconvex lens; and the ninth lens is a biconvex lens.

[0015] The tenth lens is a biconcave lens, the eleventh lens is a convex-concave lens with its concave surface facing away from the object, and the twelfth lens is a concave-convex lens with its concave surface facing the object.

[0016] Optionally, the first lens is made of HZLAF92 glass, and the second lens is made of HFK61 glass.

[0017] The seventh lens, the eighth lens, and the ninth lens are made of HFK61 type glass.

[0018] Optionally, the front objective lens group is movably disposed along the extension direction of the optical axis. The front objective lens group includes a thirteenth lens, a fourteenth lens, a fifteenth lens, and a sixteenth lens arranged sequentially from the object side to the image side. The thirteenth lens has a positive optical power. The fourteenth lens and the fifteenth lens are cemented together to form a fourth cemented lens with a negative optical power. The sixteenth lens has a positive optical power.

[0019] Optionally, the thirteenth lens is a biconvex lens, the fourteenth lens is a biconvex lens, the fifteenth lens is a biconcave lens, and the sixteenth lens is a concave-convex lens, with the concave surface of the sixteenth lens facing the object; and / or,

[0020] The fourteenth lens is made of fluorine crown glass, and the fifteenth lens is made of heavy lanthanum flint glass.

[0021] Optionally, the rear objective lens group includes a seventeenth lens and an eighteenth lens arranged sequentially from the object side to the image side, wherein the optical power of the seventeenth lens is positive and the optical power of the eighteenth lens is negative;

[0022] The seventeenth lens is made of HZLAF69 glass, and the eighteenth lens is made of HZF88 glass.

[0023] Optionally, the optical lens system further includes a reflector disposed between the front group of the objective lens and the rear group of the objective lens;

[0024] The reflector is disposed corresponding to the scanning galvanometer so that the light beam incident from the object side is transmitted through the lens group of the telescope system and projected onto the scanning galvanometer. The scanning galvanometer then reflects the light beam through the front lens group of the objective lens and projects it onto the reflector. The reflector reflects the light beam through the front lens group of the objective lens so that the light beam reflected from the reflector to the image side is parallel to and opposite to the propagation path of the light beam incident from the object side through the lens group of the telescope system.

[0025] Optionally, the optical lens further includes a filter disposed on the rear group of the objective lens near the image side. The filter can be configured as a visible light filter or an infrared filter. When the operating wavelength of the optical lens system is set to 486–656 nm, the filter is configured as a visible light filter.

[0026] When the operating wavelength of the optical lens system is set to 850–950 nm, the filter is set to a near-infrared filter.

[0027] In the technical solution provided by this invention, the optical lens system includes a telescope lens group, a scanning galvanometer, an aperture stop, a front objective lens group, a rear objective lens group, and an image plane. The telescope lens group converts incident light into a parallel beam and projects it onto the scanning galvanometer. The scanning galvanometer deflects the light path and has a fixed state and a reciprocating scanning state, enabling the optical lens system to have a staring tracking mode and a circumferential scanning search mode. In the staring tracking mode, the telescope lens group achieves continuous zoom. In the circumferential scanning search mode, the image plane is focused and paired with a 1920*1080 detector array, achieving two working wavelengths of 486–656 nm and 850–950 nm for the optical lens system. The zoom ratio Γ of the optical lens system is set to a range of 1 < Γ ≤ 5. The aperture stop coincides with the exit pupil of the telescope lens group and is also aligned with the position of the scanning galvanometer, reducing the size of the scanning galvanometer, improving scanning efficiency, and reducing off-axis aberrations. The F-number of the optical lens system is set to 4.0, which enables a pixel size of 3.5µm, in order to solve the problem of out-of-focus image points in existing optical lens systems, which cannot produce clear images in poor visibility conditions. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of an embodiment of the optical lens system corresponding to a short focal length system provided by the present invention.

[0030] Figure 2 This is a schematic diagram of a structural embodiment of the optical lens system corresponding to the central focal system provided by the present invention;

[0031] Figure 3 This is a schematic diagram of an embodiment of the optical lens system corresponding to a telephoto system provided by the present invention.

[0032] Figure 4 for Figure 1 The transfer function curve of the short focal length system at f40mm in the figure;

[0033] Figure 5 for Figure 2 The transfer function curve of the f120mm coke system in the middle coke;

[0034] Figure 6 for Figure 3 The transfer function curve of the f / 200mm telephoto system in the image;

[0035] Figure 7 for Figure 2 The optical fog penetration transfer function curve corresponding to the f120mm focal length system in the middle focal length system;

[0036] Figure 8 for Figure 3 The optical fog-penetrating transfer function curve corresponding to the telephoto system at f / 200mm;

[0037] Figure 9 The transfer function curve of the optical lens system provided by this invention corresponds to the f60mm scanning edge.

[0038] Explanation of icon numbers:

[0039] label name label name 1 Front fixed lens group 42 Eleventh Lens 11 First lens 43 The Twelfth Lens 12 Second lens 5 Scanning galvanometer 13 Third lens 6 Front group of objective lens 2 Zoom lens group 61 The Thirteenth Lens 21 Fourth lens 62 Fourteenth Lens 22 Fifth lens 63 The Fifteenth Lens 23 Sixth lens 64 The Sixteenth Lens 3 Compensating lens group 3 7 reflector 31 Seventh Lens 8 Rear objective group 32 Eighth lens 81 The Seventeenth Lens 33 Ninth Lens 82 Eighteenth Lens 4 Rear fixed lens group 9 Filter 41 Tenth Lens 10 Image

[0040] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention 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 the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0043] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0044] Search and track systems are passive detection systems capable of 360° azimuth scanning. Upon target detection, they provide azimuth and elevation information and continuously track the target at a high frame rate. They offer advantages such as all-weather operation, high sensitivity, and long detection range, making them promising for applications in defense and security fields. Traditional search and track systems rely on push-broom motion of linear detectors to achieve omnidirectional scanning imaging. However, their integration time is limited by the scan rate, typically taking tens of microseconds per pixel, resulting in low output signal strength and a high signal-to-noise ratio. Currently reported area-array scanning optical systems lack large-area, high-magnification, continuously variable-magnification area-array scanning capabilities. In practical applications, their resolution variation is limited during 360° azimuth scanning and staring tracking, especially limiting their ability to continuously track distant targets.

[0045] To address the above problems, the present invention provides an optical lens system. Figures 1 to 9 This is a specific embodiment of the optical lens system provided by the present invention.

[0046] Please see Figures 1 to 9 The optical lens system comprises multiple lens groups forming an optical axis. Each lens group includes a telescope lens group, a scanning galvanometer 5, an aperture stop, a front objective lens group 6, a rear objective lens group 8, and an image plane 10. These elements are arranged sequentially from the object side to the image side. The aperture stop coincides with the exit pupil of the telescope lens group and is located at the scanning galvanometer 5. The operating wavelength of the optical lens system is set to two bands: 486–656 nm and 850–950 nm. The magnification ratio Γ of the optical lens system is set to a range of 1 < Γ ≤ 5, and the F-number of the optical lens system is set to 4.0.

[0047] In the technical solution provided by this invention, the optical lens system includes a telescope lens group, a scanning galvanometer 5, an aperture stop, a front objective lens group 6, a rear objective lens group 8, and an image plane 10. The telescope lens group converts incident light into a parallel beam and projects it onto the scanning galvanometer 5. The scanning galvanometer 5 refracts the light path and has a fixed state and a reciprocating scanning state, enabling the optical lens system to have a staring tracking mode and a circumferential scanning search mode. In the staring tracking mode, the telescope lens group achieves continuous zoom. In the circumferential scanning search mode, the image plane 10 is in focus and is paired with a 1920*1080 detector array to achieve two working wavelengths of 486–656 nm and 850–950 nm for the optical lens system. The aperture stop coincides with the exit pupil of the telescope lens group and is also aligned with the position of the scanning galvanometer 5, reducing the size of the scanning galvanometer 5, improving scanning efficiency, and reducing off-axis aberrations. The zoom ratio Γ of the optical lens system is set to a range of 1 < Γ ≤ 5, the F number of the optical lens system is set to 4.0, the achievable pixel size is 3.5 μm, and the corresponding optical field of view coverage ranges from 1.92° × 1.08° to 9.6° × 5.41°, in order to solve the problem of out-of-focus image points in the off-axis field of view of existing optical lens systems, which cannot produce clear images in poor visibility conditions.

[0048] It should be noted that in existing technologies, the 3.0–5.0 μm wavelength band is generally designed to primarily reflect the radiation characteristics of objects, resulting in poor detail reproduction of scene targets and affecting the user's identification and judgment of targets and scenes. In this embodiment, however, the 486–656 nm wavelength band is a conventional visible light continuous zoom band. The optical lens system in this band can reflect the reflective characteristics of objects, providing better detail reproduction and conforming to the visual habits of the human eye. The near-infrared band of 850–950 nm is a fog-penetrating band. Adding a fog-penetrating band ensures that the optical system can achieve clear imaging even in low-visibility environments (such as smoke, fog, haze, etc.), enabling the optical lens system to achieve observation even in foggy conditions during the day.

[0049] It should also be noted that the different zoom ratio ranges for short and long focal lengths are due to limitations in size, imaging range, and near-field blind spots. Shorter focal lengths allow for closer object detection and have smaller near-field blind spots; longer focal lengths allow for farther object detection, but also result in larger size. In existing technologies, the near-field distance range is set to 10 meters to infinity, thus resulting in a relatively large size. However, in this embodiment, with a size of 252mm × 130mm × 83mm, the optical lens system can achieve an imaging object distance range of 1 meter to infinity while maintaining a smaller size, thus providing a wider working range.

[0050] Furthermore, in this embodiment, the F-number of the optical lens system is set to 4.0, the imaging plane 10 is not out of focus, and the image quality is clear. This avoids the reduction in resolution consistency across focal lengths caused by using a variable F-number, which would result in deviations in imaging performance from the short focal length to the long focal length.

[0051] It should be specifically noted that the scanning galvanometer 5 is located in the parallel optical path of the telescope system and coincides with the position of the aperture stop, i.e., the exit pupil position of the telescope system. Generally, the scanning galvanometer 5 has two working modes: one is the staring tracking mode: when the scanning galvanometer 5 is in the locked state, i.e., at a 45° angle with the optical axis, and the optical path is turned 90°, the system only performs continuous zoom tracking imaging. The other is the circular scan search mode: the motor drives the galvanometer to scan back and forth from the zero point along the effective scanning half angle α.

[0052] Specifically, in this embodiment, the telescope system lens group includes a front fixed lens group 1, a zoom lens group 2, a compensation lens group 3, and a rear fixed lens group 4 arranged sequentially from the object side to the image side. Both the zoom lens group 2 and the compensation lens group 3 can be movable along the extension direction of the optical axis, allowing the focal length f of the optical lens system to be continuously zoomed between 40mm and 200mm. Because the zoom lens group 2 can achieve a focal length change by moving within the optical path, but this zoom group causes a shift in the image plane 10, it is necessary to compensate by setting the compensation lens group 3 to perform a non-linear motion according to a certain curve. This ensures that the position of the image plane 10 does not change during the zoom process, thus maintaining a clear image.

[0053] During the movement of the zoom lens group 2 and the compensation lens group 3, the optical lens system has a first typical working state for achieving short focal length, a second typical working state for achieving medium focal length, and a third typical working state for achieving long focal length.

[0054] The description will be based on a position of the optical lens system in its first typical operating state; please refer to [link to relevant documentation]. Figure 1 and Figure 4 The zoom lens group 2 moves closer to the front fixed lens group 1. The distance between the center of the surface of the fourth lens 21 and the third lens 13 in the zoom lens group 2 is 3 mm on the optical axis. The compensation lens group 3 moves closer to the rear fixed lens group 4. The distance between the center of the surface of the ninth lens 33 and the tenth lens 41 is 3.5 mm on the optical axis. The distance between the center of the surface of the sixth lens 23 and the seventh lens 31 is 141.3 mm on the optical axis. The focal length of the optical lens system is adjusted to 40 mm.

[0055] The description is based on a position of the optical lens system in the second typical operating state; please refer to [link / reference]. Figure 2 and Figure 5 The zoom lens group 2 gradually moves away from the front fixed lens group 1. The distance between the center of the surfaces of the fourth lens 21 and the third lens 13 in the zoom lens group 2 is 84.8 mm on the optical axis. The compensation lens group 3 moves away from the rear fixed lens group 4. The distance between the center of the surfaces of the ninth lens 33 and the tenth lens 41 is 22 mm on the optical axis. The distance between the center of the surfaces of the sixth lens 23 and the seventh lens 31 is 41 mm on the optical axis. The focal length of the optical lens system is adjusted to 120 mm.

[0056] The description is based on a position of the optical lens system in the third typical operating state; please refer to [link / reference]. Figure 3 and Figure 6 The zoom lens group 2 moves further away from the front fixed lens group 1. The distance between the center of the surfaces of the fourth lens 21 and the third lens 13 in the zoom lens group 2 is 105.4 mm on the optical axis. The compensation lens group 3 moves further away from the rear fixed lens group 4 and closer to the zoom lens group 2. The distance between the center of the surfaces of the ninth lens 33 and the tenth lens 41 is 38.93 mm on the optical axis. The distance between the center of the surfaces of the sixth lens 23 and the seventh lens 31 is 3.5 mm on the optical axis. The focal length of the optical lens system is adjusted to 200 mm.

[0057] according to Figure 4 The diagram below illustrates the optical modulation transfer function for a 40mm short focal length lens. Figure 5 The diagram below illustrates the optical modulation transfer function for a 120mm mid-focal length. Figure 6 The optical modulation transfer function diagram for a 200mm telephoto lens clearly shows that at 100lp / mm, the MTF for each focal length within 0.8 Fields reaches above 0.2, indicating good image quality.

[0058] Please see Figure 7 and Figure 8 , Figures 7-8 This is the optical modulation transfer function (MTF) diagram for fog-penetrating medium and long focal lengths. In the fog-penetrating segment, the radiation characteristics of the scene target need to be considered, and the high-frequency target details cannot be reflected. Therefore, in the fog-penetrating segment at 80 lp / mm, the MTF within 0.8 Field for each focal length reaches above 0.1, which has good image quality.

[0059] The effective scanning half-angle α of the scanning galvanometer 5 is determined by the magnification M of the telescope system corresponding to a scanning focal length of 60mm, the turntable rotation speed ω, and the detector integration time t. The compensation angle for the motion blur produced by the scanning galvanometer 5 on the image plane 10 after the turntable rotation can be set to tanα = Mtan(ωt / 2).

[0060] The area array perimeter scan search system includes the following steps:

[0061] Step 1: Design of the lens group of the telescope system: Based on the platform rotation speed, determine the minimum field of view increase ΔωFOV = ωt for the telescope system that meets the requirements of retrace compensation without vignetting or light blocking, where ω is the platform rotation speed and t is the integration time of the optical system's array detector; the total field of view of the telescope system is obtained as ωFOV = ωmax + ΔωFOV, where ωmax is the maximum field of view required when there is no scanning in the optical system.

[0062] Step 2: Based on the entrance pupil diameter and structural size limitations of the lens group of the telescope system, determine the telescope system magnification M with the smallest size of the scanning galvanometer 5 in the telescope system;

[0063] Step 3: Based on the magnification of the telescope system M = f0' / fe', and combined with the F-number of the system, determine the focal lengths of the objective lens group f01' to f02' and the focal length of the eyepiece group fe';

[0064] Step 4: Strictly match the exit pupil position of the telescope system lens group with the entrance pupil position of the objective lens front group 6, and place the scanning galvanometer 5 at the telescope exit pupil position;

[0065] Step 5: Match and optimize the lens group and the front objective lens group 6 of the telescope system to obtain the area array scanning optical system.

[0066] In this embodiment, the optical lens system can perform area scanning at a focal length of 60mm, with the platform search speed set to 90° / s and the detector integration time set to 10ms.

[0067] Please see Figure 9 , Figure 9 This is the optical modulation transfer function (MTF) diagram for scanning search at a focal length of 60mm. This focal length is used for panoramic scanning search, requiring rapid scanning to locate the target. The field of view must cover the rotation angle of the turntable. Therefore, when the swing direction of the scanning galvanometer 5 is opposite to the rotation direction of the turntable, it ensures no image shift during rotation and maintains a clear image at all times. Figure 9 The MTF (Mean Transmission Scale) is above 0.5 within 0.8 Field at the position with the largest field of view, which indicates that the system has a clear imaging effect during the scanning process.

[0068] More specifically, in this embodiment, the front fixed lens group 1 includes a first lens 11, a second lens 12, and a third lens 13 arranged sequentially from the object side to the image side. The first lens 11 and the second lens 12 are cemented together to form a first cemented lens. The first lens 11 is made of HZLAF92 glass, and the second lens 12 is made of HFK61 glass to eliminate chromatic aberration in the optical lens system. The zoom lens group 2 includes a fourth lens 21, a fifth lens 22, and a sixth lens 23 arranged sequentially from the object side to the image side. The fourth lens 21 has a positive optical power, and the fifth lens 22 and the sixth lens 23 are cemented together to form a second cemented lens with a negative optical power. By setting the fourth lens 21 with a positive optical power and the second cemented lens with a negative optical power, spherical aberration and astigmatism are effectively compensated. The compensation lens group 3 includes a seventh lens 31, an eighth lens 32, and a ninth lens 33 arranged sequentially from the object side to the image side. The seventh lens 31, the eighth lens 32, and the ninth lens 33 are made of HFK61 type glass. The seventh lens 31 has a negative optical power, the eighth lens 32 has a positive optical power, and the ninth lens 33 has a positive optical power. This reasonable combination of positive and negative lenses cancels out spherical aberration and coma. The rear fixed lens group 4 includes a tenth lens 41, an eleventh lens 42, and a twelfth lens 43 arranged sequentially from the object side to the image side. The tenth lens 41 and the eleventh lens 42 are cemented together to form a third cemented lens with a negative optical power. The twelfth lens 43 has a positive optical power. The tenth lens 41 and the eleventh lens 42 are made of lanthanum crown glass and heavy flint glass. The third cemented lens effectively eliminates dispersion and second-order spectral density. At the same time, combined with the twelfth lens 43 with a positive optical power, it can effectively correct spherical aberration, astigmatism, and distortion. In this way, by rationally allocating the optical power of the lenses and adjusting the glass shape and material combination, chromatic aberration, dispersion and secondary spectrum can be effectively eliminated, so that spherical aberration, coma and astigmatism on each lens can compensate and cancel each other out, so as to achieve a clear imaging effect.

[0069] More specifically, in this embodiment, the first lens 11 is a convex-concave lens, with its concave surface facing away from the object; the second lens 12 is a biconvex lens; the third lens 13 is a convex-concave lens, with its concave surface facing away from the object; the fourth lens 21 is a convex-concave lens, with its concave surface facing away from the object; the fifth lens 22 is a biconvex lens; the sixth lens 23 is a convex-concave lens, with its concave surface facing away from the object; the seventh lens 31 is a convex-concave lens, with its concave surface facing away from the object; the eighth lens 32 is a biconvex lens; the ninth lens 33 is a biconvex lens; the tenth lens 41 is a biconvex lens; the eleventh lens 42 is a convex-concave lens, with its concave surface facing away from the object; and the twelfth lens 43 is a concave-convex lens, with its concave surface facing the object. The telescope system lens group consists of the front fixed lens group 1, the zoom lens group 2, the compensation lens group 3, and the rear fixed lens group 4 to complete the zoom function. The output light of the telescope system lens group is parallel light. That is, the aperture stop of the entire system is placed after the rear fixed lens group 4, which is at the exit pupil position of the telescope system. Placing the scanning galvanometer 5 at this position can ensure that the galvanometer has a small aperture and light weight, and that the motor drives the galvanometer to swing at a high speed, thereby improving the scanning speed of the galvanometer and reducing the impact of off-axis aberrations on image quality during back-and-forth swinging.

[0070] Specifically, in this embodiment, the front objective lens group 6 is movably arranged along the extension direction of the optical axis. The front objective lens group 6 includes a thirteenth lens 61, a fourteenth lens 62, a fifteenth lens 63, and a sixteenth lens 64 arranged sequentially from the object side to the image side. The thirteenth lens 61 has a positive optical power. The fourteenth lens 62 and the fifteenth lens 63 are cemented together to form a fourth cemented lens with a negative optical power. The sixteenth lens 64 has a positive optical power.

[0071] More specifically, in this embodiment, the thirteenth lens 61 is a biconvex lens, the fourteenth lens 62 is a biconvex lens, the fifteenth lens 63 is a biconcave lens, and the sixteenth lens 64 is a concave-convex lens. The concave surface of the sixteenth lens 64 faces the object side. The fourteenth lens 62 is made of fluorine crown glass, and the fifteenth lens 63 is made of heavy lanthanum flint glass. This arrangement has a positive effect on eliminating aberrations such as spherical aberration, coma, and chromatic aberration. Furthermore, the front objective lens group 6 is movably arranged along the extension direction of the optical axis, enabling clear imaging at a close object distance of 1m, reducing near-distance blind spots and imaging at high and low temperatures (-40℃ to +60℃), while also minimizing the impact of temperature changes on image quality.

[0072] Specifically, the rear objective lens group 8 includes a seventeenth lens 81 and an eighteenth lens 82 arranged sequentially from the object side to the image side. The seventeenth lens 81 has a positive optical power, and the eighteenth lens 82 has a negative optical power. The seventeenth lens 81 is made of HZLAF69 glass, and the eighteenth lens 82 is made of HZF88 glass. This is used to eliminate residual astigmatism, field distortion, and aberrations caused by the preceding lenses.

[0073] Furthermore, since the optical lens system includes at least eighteen lenses, and the scanning galvanometer 5 reflects the light path, the optical lens system is relatively large. To reduce the size of the optical lens system, in this embodiment, the optical lens system also includes a reflecting mirror 7. The reflecting mirror 7 is disposed between the front objective lens group 6 and the rear objective lens group 8. The reflecting mirror 7 is correspondingly arranged with the scanning galvanometer 5 so that the light beam incident from the object side is transmitted through the lens group of the telescope system and projected onto the scanning galvanometer 5. Since the angle between the scanning galvanometer 5 and the incident light path is 45°, it can ultimately deflect the light beam by 90°. The scanning galvanometer 5 reflects the light beam, which is then projected onto the reflecting mirror 7 via the front objective lens group 6. The angle between the reflecting mirror 7 and the optical path is not specifically limited; it only needs to cooperate with the scanning galvanometer 5 to allow the light beam to be refracted. Preferably, the angle between the reflecting mirror 7 and the optical path is 45°, thus reversing the optical path by 90°. The reflecting mirror 7 reflects the light beam through the front objective lens group 6, ensuring that the light beam reflected from the reflecting mirror 7 to the image side is parallel and opposite to the propagation path of the light beam incident from the object side through the lens group of the telescope system. This reduces the overall system volume and the overall length of the optical lens system.

[0074] Furthermore, to reduce the impact of optical noise on image quality and also reduce the processing workload of the subsequent photoelectric conversion section, in this embodiment, the optical lens system further includes a filter 9 disposed near the image side of the rear group 8 of the objective lens. The filter 9 can be configured as a visible light filter or a near-infrared filter. In clear weather with high visibility, when the operating wavelength of the optical lens system is set to 486–656 nm, the filter 9 is configured as a visible light filter to filter out infrared light. During daytime weather conditions such as fog or haze, when the operating wavelength of the optical lens system is set to 850–950 nm, the filter 9 is configured as a near-infrared filter to filter out visible light, thus reducing the impact of optical noise on image quality.

[0075] Specifically, the image plane 10 can be understood as the surface of the photosensitive chip facing the object, that is, the surface of a camera element such as a CCD or CMOS. It can be understood that the light carrying the information of the object can pass through the front fixed lens group 1, the zoom lens group 2, the compensation lens group 3 and the rear fixed lens group 4, the scanning galvanometer 5, the front objective lens group 6, the reflecting mirror 7, the rear objective lens group 8 and the filter 9 in sequence and finally be imaged on the image plane 10.

[0076] It should be noted that, in one embodiment, the basic parameters of the optical lens system are shown in Table 1, where the radius of curvature and thickness are in millimeters (mm).

[0077] Table 1

[0078]

[0079]

[0080] In summary, by moving the zoom lens group 2 and the compensation lens group 3, and by scanning back and forth with the scanning galvanometer 5, scanning at a focal length of 60mm and continuous zoom staring tracking are achieved.

[0081] To ensure accurate image registration across the entire field of view during scanning at multiple focal lengths, thus guaranteeing clear and stable imaging.

[0082] The distortion caused by the swing of the scanning galvanometer 5 is controlled to be less than 1%, ensuring accurate image registration across the entire field of view during the scanning process at a focal length of 60mm, thus guaranteeing clear and stable imaging.

[0083] The optical lens system of this invention is a 40mm-200mm visible light continuous zoom area array scanning optical system, with operating wavelengths of 486-656nm and 850-950nm; the detector array is 1920×1080, with a pixel size of 3.5µm; the system F-number is 4. The focal length of the system is f1 = 40mm for short focal length and f2 = 200mm for long focal length, and the zoom ratio of the system is: Γ = f2 / f1 = 4; the corresponding optical field of view coverage ranges from 1.92°×1.08° to 9.6°×5.41°.

[0084] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An optical lens system characterized in that, The optical lens system comprises a plurality of mirror groups, an optical axis is formed between the plurality of mirror groups, the plurality of mirror groups comprise a telescopic system lens group, a scanning galvanometer, an aperture diaphragm, a front objective lens group, a rear objective lens group and an image plane, and the telescopic system lens group, the scanning galvanometer, the front objective lens group, the rear objective lens group and the image plane are sequentially arranged from the object side to the image side, and the aperture diaphragm coincides with the exit pupil position of the telescopic system lens group and is located at the scanning galvanometer; The working waveband of the optical lens system is set to two wavebands of 486-656 nm and 850-950 nm, the range of the zoom ratio Γ of the optical lens system is set to 1 < Γ ≤ 5, and the F number of the optical lens system is set to 4.0; The telescopic system lens group is composed of a front fixed lens group, a zoom lens group, a compensation lens group and a rear fixed lens group sequentially arranged from the object side to the image side: The front fixed lens group is composed of a first lens, a second lens and a third lens sequentially arranged from the object side to the image side, and the first lens and the second lens are glued to form a first glued lens; The zoom lens group is composed of a fourth lens, a fifth lens and a sixth lens sequentially arranged from the object side to the image side, the fourth lens has a positive refractive power, and the fifth lens and the sixth lens are glued to form a second glued lens with a negative refractive power; The compensation lens group is composed of a seventh lens, an eighth lens and a ninth lens sequentially arranged from the object side to the image side, the seventh lens has a negative refractive power, the eighth lens has a positive refractive power, and the ninth lens has a positive refractive power; The rear fixed lens group is composed of a tenth lens, an eleventh lens and a twelfth lens sequentially arranged from the object side to the image side, the tenth lens and the eleventh lens are glued to form a third glued lens with a negative refractive power, and the twelfth lens has a positive refractive power; The zoom lens group and the compensation lens group are movably arranged along the extension direction of the optical axis, so that the focal length f of the optical lens system is set to be continuously variable between 40 mm and 200 mm.

2. The optical lens system of claim 1, wherein, The first lens is a convex-concave lens, the concave surface of the first lens faces away from the object side, the second lens is a double-convex lens, the third lens is a convex-concave lens, and the concave surface of the third lens faces away from the object side; The fourth lens is a convex-concave lens, the concave surface of the fourth lens faces away from the object side, the fifth lens is a double-concave lens, the sixth lens is a convex-concave lens, and the concave surface of the sixth lens faces away from the object side; The seventh lens is a convex-concave lens, the concave surface of the seventh lens faces away from the object side, the eighth lens is a double-convex lens, and the ninth lens is a double-convex lens; The tenth lens is a double-concave lens, the eleventh lens is a convex-concave lens, the concave surface of the eleventh lens faces away from the object side, the twelfth lens is a concave-convex lens, and the concave surface of the twelfth lens faces the object side.

3. The optical lens system of claim 1, wherein, The material of the first lens is HZLAF92 type glass, and the material of the second lens is HFK61 type glass. The material of the seventh lens, the eighth lens and the ninth lens is a glass of HFK61 model.

4. The optical lens system of claim 1, wherein, The objective lens front group is movably arranged along the extension direction of the optical axis, and is composed of a thirteenth lens, a fourteenth lens, a fifteenth lens and a sixteenth lens arranged from the object side to the image side in sequence.

5. The optical lens system of claim 4, wherein, The thirteenth lens is a double convex lens, the fourteenth lens is a double convex lens, the fifteenth lens is a double concave lens, and the sixteenth lens is a concave-convex lens, and the concave surface of the sixteenth lens is arranged towards the object side; and / or, The material of the fourteenth lens is fluorite glass, and the material of the fifteenth lens is heavy lanthanum flint glass.

6. The optical lens system of claim 1, wherein, The objective lens rear group is composed of a seventeenth lens and an eighteenth lens arranged from the object side to the image side in sequence, the seventeenth lens has positive refractive power, and the eighteenth lens has negative refractive power. The material of the seventeenth lens is a glass of HZLAF69 model, and the material of the eighteenth lens is a glass of HZF88 model.

7. The optical lens system of claim 1, wherein, The optical lens system further comprises a mirror arranged between the objective lens front group and the objective lens rear group; The mirror is arranged corresponding to the scanning galvanometer, so that the light beam incident from the object side is transmitted through the telescope lens group and then projected to the scanning galvanometer, the scanning galvanometer reflects the light beam to the objective lens front group through the objective lens front group, so that the light beam reflected from the mirror to the image side is parallel and opposite to the propagation path of the light beam incident from the object side through the telescope lens group.

8. The optical lens system of claim 1, wherein, The optical lens system further comprises a filter arranged near the image side of the objective lens rear group, and the filter can be set as a visible light filter or a near-infrared filter. When the working waveband of the optical lens system is set as 486-656nm, the filter is set as a visible light filter. When the working waveband of the optical lens system is set as 850-950nm, the filter is set as a near-infrared filter.

Images