Zoom lens

Abstract

The invention discloses a zoom lens. A focusing lens group with negative focal power, a diaphragm and a zoom lens group with positive focal power are sequentially arranged from an object space to an image space along an optical axis; the focusing lens group consists of a first lens with negative focal power, a second lens with negative focal power and a third lens with positive focal power; the zoom lens group consists of a fourth lens with positive focal power, a fifth lens with positive focal power, a sixth lens with negative focal power, a seventh lens with positive focal power, an eighth lens with negative focal power and a ninth lens with positive focal power; in the zoom lens, the number of lens groups with focal power is two; the focusing lens group and the zoom lens group are movably arranged along the direction of the optical axis; when the focusing lens group and the zoom lens group cooperatively move along the direction of the optical axis, switching of the zoom lens between the wide-angle end and the long-focus end is realized. By adopting the technical scheme, the zoom lens has the advantages of large aperture, infrared high and low temperature confocal property, high definition, small size and the like.

Description

Technical Field

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

[0002] In recent years, the demand for lenses in the surveillance market has become increasingly diversified. In the security field, zoom lenses have been widely used due to their advantages such as long shooting distance and wide shooting angle.

[0003] With technological advancements, cameras are increasingly moving towards miniaturization and refinement, which places stricter demands on mainstream zoom lenses. Therefore, achieving advantages such as large aperture, infrared high / low temperature confocal focusing, high resolution, and small size in zoom lenses has become a pressing technical challenge. Summary of the Invention

[0004] This invention provides a zoom lens that has advantages such as large aperture, infrared high and low temperature confocal focus, high definition, and small size.

[0005] According to one aspect of the present invention, a zoom lens is provided, comprising: Along the optical axis, from the object side to the image side, a focusing lens group with negative optical power, an aperture, and a zoom lens group with positive optical power are arranged in sequence. The focusing lens group consists of a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power; The zoom lens group consists of a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with negative optical power, a seventh lens with positive optical power, an eighth lens with negative optical power, and a ninth lens with positive optical power. The zoom lens has two lens groups with optical power. The focusing lens group and the zoom lens group are moved along the direction of the optical axis; when the focusing lens group and the zoom lens group move together along the direction of the optical axis, the zoom lens can switch between the wide-angle end and the telephoto end.

[0006] Optionally, 1.17 ≤ |F2 / F1| ≤ 1.21; Wherein, F1 is the optical power of the focusing lens group; F2 is the optical power of the zoom lens group.

[0007] Optionally, 0.870≤F1m / F1≤0.910; 0.800≤F2m / F2≤1.200; Wherein, F1m represents the maximum optical power of a single lens in the focusing lens group, F2m represents the maximum optical power of a single lens in the zoom lens group, F1 is the optical power of the focusing lens group, and F2 is the optical power of the zoom lens group.

[0008] Optionally, in the focusing lens group, The object-side surface of the first lens is convex, and the image-side surface of the first lens is concave. The object-side surface of the second lens is concave, and the image-side surface of the second lens is also concave. The object-side surface of the third lens is convex, and the image-side surface of the third lens is convex. In the zoom lens group, The object-side surface of the fourth lens is convex, and the image-side surface of the fourth lens is convex. The object-side surface of the fifth lens is convex, and the image-side surface of the fifth lens is concave. The object-side surface of the sixth lens is concave, and the image-side surface of the sixth lens is also concave. The object-side surface of the seventh lens is convex, and the image-side surface of the seventh lens is convex. The object-side surface of the eighth lens is concave, and the image-side surface of the eighth lens is convex. The object-side surface of the ninth lens is convex, and the image-side surface of the ninth lens is concave.

[0009] Optionally, the second lens, the third lens, the fifth lens, the eighth lens, and the ninth lens are all plastic aspherical lenses; The fourth lens is a glass aspherical lens.

[0010] Optionally, 1.437 ≤ nd4 ≤ 1.640; Wherein, nd4 is the refractive index of the fourth lens.

[0011] Optionally, the sixth lens and the seventh lens form a cemented lens group; 0.008≤F67 / F2≤0.140; Wherein, F67 represents the optical power of the cemented lens group composed of the sixth lens and the seventh lens, and F2 is the optical power of the zoom lens group.

[0012] Optionally, 3.380 ≤ L / FW ≤ 3.620; Wherein, L represents the maximum distance from the center of the aperture stop to the side surface of the first lens during zooming, and FW represents the focal length of the zoom lens at the wide-angle end.

[0013] Optional, FT / FW ≤ 2.400; Wherein, FW represents the focal length of the zoom lens at the wide-angle end, and FT represents the focal length of the zoom lens at the telephoto end.

[0014] Optionally, 0.105≤S1 / TTL≤0.116, 0.150≤S2 / TTL≤0.160; Wherein, S1 represents the maximum distance that the focusing lens group can move, S2 represents the maximum distance that the zoom lens group can move, and TTL represents the distance from the vertex of the object side of the first lens to the image plane when the zoom lens is at the wide-angle end.

[0015] The technical solution of this invention adopts a dual-group structure that simplifies zoom functionality and reduces the number of lenses, resulting in a smaller zoom lens size. This allows it to be compatible with mainstream 1 / 2.7″ sensors, meeting the needs of a wider range of applications. Simultaneously, it provides better correction for aberrations, chromatic aberration, and sensitivity, achieving full-band confocal focusing in the 436nm-850nm wavelength range with a larger aperture and higher image quality, making the zoom lens suitable for more application scenarios. Furthermore, the zoom lens uses only nine lenses, allowing for better control of material and coating costs, thereby reducing lens costs. Using the aforementioned optical power combination, the flexibility of the zoom lens at different magnifications is balanced, achieving an optimal solution in performance and parameter balance to meet the requirements of more applications while controlling costs, thus satisfying market demands.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a zoom lens at the wide-angle end according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a zoom lens at the telephoto end according to an embodiment of the present invention; Figure 3 yes Figure 1 The diagram showing the chromatic aberration at the wide-angle end of the zoom lens; Figures 4 to 9 yes Figure 1 The fan-shaped pattern at the wide-angle end of the zoom lens is shown. Figure 10 yes Figure 1 The diagram shows the axial aberration at the wide-angle end of the zoom lens. Figure 11 yes Figure 2 The diagram showing the vertical chromatic aberration at the telephoto end of the zoom lens; Figures 12 to 17 yes Figure 2 The image shows the light field diagram at the telephoto end of the zoom lens. Figure 18 yes Figure 2 The diagram shows the axial aberration at the telephoto end of the zoom lens. Figure 19 This is a schematic diagram of another zoom lens at the wide-angle end provided in an embodiment of the present invention; Figure 20 This is a schematic diagram of another zoom lens at the telephoto end provided in an embodiment of the present invention; Figure 21 yes Figure 19 The diagram showing the chromatic aberration at the wide-angle end of the zoom lens; Figures 22 to 27 yes Figure 19 The fan-shaped pattern at the wide-angle end of the zoom lens is shown. Figure 28 yes Figure 19 The diagram shows the axial aberration at the wide-angle end of the zoom lens. Figure 29 yes Figure 20 The diagram showing the vertical chromatic aberration at the telephoto end of the zoom lens; Figures 30 to 35 yes Figure 20 The image shows the light field diagram at the telephoto end of the zoom lens. Figure 36 yes Figure 20 The diagram shows the axial aberration at the telephoto end of the zoom lens. Figure 37 This is a schematic diagram of the structure of another zoom lens at the wide-angle end provided in an embodiment of the present invention; Figure 38 This is a schematic diagram of the structure of another zoom lens at the telephoto end provided in an embodiment of the present invention; Figure 39 yes Figure 37 The diagram showing the chromatic aberration at the wide-angle end of the zoom lens; Figures 40 to 45 yes Figure 37 The fan-shaped pattern at the wide-angle end of the zoom lens is shown. Figure 46 yes Figure 37 The diagram shows the axial aberration at the wide-angle end of the zoom lens. Figure 47 yes Figure 38 The diagram showing the vertical chromatic aberration at the telephoto end of the zoom lens; Figures 48 to 53 yes Figure 38 The image shows the light field diagram at the telephoto end of the zoom lens. Figure 54 yes Figure 38 The diagram shows the axial aberration at the telephoto end of the zoom lens. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be fully described below with reference to the accompanying drawings of the embodiments of this invention through specific implementation methods. Obviously, the described embodiments are only some, not all, embodiments of this invention. Various modifications and variations can be made to this invention without departing from the spirit or scope of this invention, which will be obvious to those skilled in the art. Therefore, this invention is intended to cover modifications and variations of this invention that fall within the scope of the corresponding claims (the claimed technical solutions) and their equivalents.

[0020] Furthermore, the terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as "an," "one," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "including" or "comprising" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. In addition, descriptions of "same" or "equal" in the embodiments of this disclosure do not mean that two objects are completely equal in size or shape; they are allowed to be approximately the same or approximately equal within a certain error range.

[0021] It should be noted that the implementation methods provided in the embodiments of the present invention can be combined with each other without contradiction.

[0022] Figure 1 This is a schematic diagram of the structure of a zoom lens at the wide-angle end according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a zoom lens at the telephoto end according to an embodiment of the present invention. (Refer to...) Figure 1 and Figure 2The zoom lens includes a focusing lens group G1 with negative optical power, an aperture stop STO, and a zoom lens group G2 with positive optical power, arranged sequentially from the object side to the image side along the optical axis. The focusing lens group G1 consists of a first lens L1 with negative optical power, a second lens L2 with negative optical power, and a third lens L3 with positive optical power. The zoom lens group G2 consists of a fourth lens L4 with positive optical power, a fifth lens L5 with positive optical power, a sixth lens L6 with negative optical power, and a zoom lens group G2 with positive optical power. The zoom lens consists of a seventh lens L7 with positive optical power, an eighth lens L8 with negative optical power, and a ninth lens L9 with positive optical power. Within the zoom lens, there are two lens groups with optical power: a focusing lens group G1 and a zoom lens group G2. The focusing lens group G1 and the zoom lens group G2 are moved along the optical axis. When the focusing lens group G1 and the zoom lens group G2 move together along the optical axis, the zoom lens switches between wide-angle and telephoto ends.

[0023] The focusing lens group G1, the aperture stop STO, and the zoom lens group G2 can be set in one lens barrel. Figure 1 and Figure 2 Within the lens barrel (not shown), the focusing lens group G1 and the zoom lens group G2 can reciprocate along the optical axis. Through the coordinated movement of these two groups, the focal length of the zoom lens can continuously change from short to long focal length, ensuring high image quality at all focal points. The aperture stop STO of the zoom lens is located between the positive optical power third lens L3 and the positive optical power fourth lens L4. By changing the positions of the focusing lens group G1 and the zoom lens group G2 on the optical axis, the zoom lens can be switched between wide-angle and telephoto ends at any time.

[0024] It is understandable that during the zoom process achieved by moving the focusing lens group G1 and the zoom lens group G2, the zoom lens is at its widest focal length (i.e., at the wide-angle end) and at its longest focal length (i.e., at the telephoto end). At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical powers, as well as different lengths or shapes.

[0025] In this embodiment of the invention, setting a negative optical power focusing lens group G1 before the aperture stop STO of the zoom lens ensures a larger light aperture after light passes through, increasing the aperture number of the optical system. This ensures clear imaging of both near and far objects simultaneously, and clear imaging even in low-light environments, meeting the needs of use under different conditions. The focusing lens group G1, in conjunction with the fourth lens L4 in the zoom lens group G2, allows light to pass smoothly through the aperture stop STO, avoiding stray light such as reflections at the STO position. It also adjusts the aberrations of the zoom lens to a certain extent, ensuring aberration balance and stable high and low temperature performance. The fifth lens L5, sixth lens L6, and seventh lens L7 in the zoom lens group G2 correct aberrations at the rear of the zoom lens, and together with the focusing lens group G1 in front of the aperture stop STO, stabilize the imaging quality of the optical system.

[0026] It should be noted that optical power is equal to the difference between the image-side convergence and the object-side convergence, and its value is the reciprocal of the focal length. It characterizes the ability of an optical system to deflect light rays. The larger the absolute value of optical power, the stronger the bending ability of light rays; the smaller the absolute value of optical power, the weaker the bending ability of light rays. When the optical power is positive, the refraction of light rays is converging; when the optical power is negative, the refraction of light rays is diverging. Optical power can be used to characterize a single refractive surface of a lens (i.e., one surface of the lens), a single lens, or a system formed by multiple lenses (i.e., a lens group).

[0027] In this embodiment of the invention, by setting a first lens L1 with negative optical power, a second lens L2 with negative optical power, and a third lens L3 with positive optical power in the focusing lens group G1, the focusing lens group G1 has negative optical power. By setting a fourth lens L4 with positive optical power, a fifth lens L5 with positive optical power, a sixth lens L6 with negative optical power, a seventh lens L7 with positive optical power, an eighth lens L8 with negative optical power, and a ninth lens L9 with positive optical power in the zoom lens group G2, the zoom lens group G2 has positive optical power. This allows the optical powers of the focusing lens group G1 and the zoom lens group G2 to complement each other, ensuring that the zoom lens can have a large aperture and a long focal length. At the same time, after light enters through the focusing lens group G1, it can smoothly pass through the zoom lens group G2, which helps to reduce aberrations and chromatic aberrations in the zoom lens and ensures that the zoom lens has high image quality.

[0028] Furthermore, an aperture stop STO is placed between the focusing lens group G1 and the zoom lens group G2. The aperture stop STO can adjust the propagation direction of the light beam, which helps to improve image quality. By placing the aperture stop STO between the focusing lens group G1 and the zoom lens group G2, the advanced aberrations of the zoom lens can be controlled at the front end, ensuring that the rear end of the zoom lens has a high image height. This expands the imaging target area while improving image quality, making the zoom lens suitable for different application scenarios.

[0029] For example, continue to refer to Figure 1 and Figure 2 Along the direction from the object plane to the image plane, a planar glass lens CG is also provided. The planar glass lens CG is located on the image-side surface of the ninth lens L9. The planar glass lens CG protects the photosensitive chip in the imaging sensor, which converts the light signals collected by the zoom lens into electrical signals, thereby ensuring the imaging effect of the zoom lens. It should be noted that... Figure 1 and Figure 2 The structural diagrams corresponding to the subsequent embodiments only exemplarily show the structure of the zoom lens at the wide-angle end and the telephoto end, but are not limited thereto. In other optional embodiments, the zoom lens at the wide-angle end and the telephoto end can also have other structures. The embodiments of the present invention do not limit the shape of the zoom lens, such as spherical or aspherical.

[0030] In summary, the zoom lens provided by this invention adopts a dual-group structure that simplifies zoom functionality and reduces the number of lenses, resulting in a smaller lens size. This allows it to be compatible with mainstream 1 / 2.7″ sensors, meeting the needs of a wider range of applications. Simultaneously, it offers good correction for aberrations, chromatic aberration, and sensitivity, achieving full-band confocal focusing in the 436nm-850nm wavelength range with a larger aperture and higher image quality, making it suitable for more application scenarios. Furthermore, the zoom lens uses only nine lenses, allowing for better control of material and coating costs, thus reducing lens cost. The aforementioned optical power combination balances the flexibility of the zoom lens at different magnifications, achieving an optimal solution in performance and parameter balance to meet diverse usage requirements while controlling costs, thus satisfying market demands.

[0031] Optionally, 1.17 ≤ |F2 / F1| ≤ 1.21; where F1 is the optical power of the focusing lens group G1 and F2 is the optical power of the zoom lens group G2. By matching the signs and ratio ranges of the optical power of the focusing lens group G1 and the zoom lens group G2, a reasonable match of optical power can be achieved, solving the image plane drift problem during the zooming process of short-to-long zoom lenses.

[0032] Optionally, 0.870≤F1m / F1≤0.910; 0.800≤F2m / F2≤1.200; where F1m represents the maximum optical power of a single lens in the focusing lens group G1, F2m represents the maximum optical power of a single lens in the zoom lens group G2, F1 is the optical power of the focusing lens group G1, and F2 is the optical power of the zoom lens group G2.

[0033] By allocating the optical power of the lenses in the focusing lens group G1 and the zoom lens group G2, a division of labor can be achieved, with the primary lens dominating refractive power and the auxiliary lenses focusing on correction. This improves the targeting and efficiency of aberration correction and enhances image quality. In addition, this allocation method can greatly simplify the group structure, adapt to the overall length of the lens, reduce assembly difficulty, and meet the design requirements of lightweighting. Thus, it can simultaneously meet the requirements of low cost and high reliability.

[0034] Optionally, in the focusing lens group G1, the object-side surface of the first lens L1 is convex, and the image-side surface of the first lens L1 is concave; the object-side surface of the second lens L2 is concave, and the image-side surface of the second lens L2 is concave; the object-side surface of the third lens L3 is convex, and the image-side surface of the third lens L3 is convex; in the zoom lens group G2, the object-side surface of the fourth lens L4 is convex, and the image-side surface of the fourth lens L4 is convex; the object-side surface of the fifth lens L5 is convex, and the image-side surface of the fifth lens L5 is concave; the object-side surface of the sixth lens L6 is concave, and the image-side surface of the sixth lens L6 is concave; the object-side surface of the seventh lens L7 is convex, and the image-side surface of the seventh lens L7 is convex; the object-side surface of the eighth lens L8 is concave, and the image-side surface of the eighth lens L8 is convex; the object-side surface of the ninth lens L9 is convex, and the image-side surface of the ninth lens L9 is concave. This configuration allows light from the object side to pass smoothly through the lenses within the zoom lens after entering it, thereby effectively reducing optical distortion and improving image quality.

[0035] Based on the above embodiments, the eighth lens L8 and the ninth lens L9 have inversion, which can more accurately control the light and match the 1 / 2.7″ chip. At the same time, it is also beneficial to further correct aberrations and achieve better imaging quality.

[0036] Optionally, the second lens L2, the third lens L3, the fifth lens L5, the eighth lens L8, and the ninth lens L9 are all plastic aspherical lenses; the fourth lens L4 is a glass aspherical lens.

[0037] In this way, the aspherical lens used in the focusing lens group G1 and the aspherical lens used in the zoom lens group G2 can correct the advanced chromatic aberration and aberration of the lens, control the aberration balance of the focusing lens group G1 and the zoom lens group G2, ensure that the structure after the light enters the aperture stop STO will not produce serious aberrations, and improve the imaging quality of the optical system.

[0038] Aspherical lenses possess excellent capabilities for controlling higher aberrations in optical systems. The use of an aspherical lens in the fourth lens L4 further reduces higher aberrations after light passes through the aperture stop STO, improving the imaging quality of the optical system. Furthermore, glass lenses are temperature-insensitive; using a glass aspherical lens in the fourth lens L4 allows for more consistent performance of the zoom lens under different temperature conditions, exhibiting stable performance at both high and low temperatures. The introduction of glass aspherical lenses also significantly corrects chromatic aberration and higher aberrations in the lens, offering a wider range of choices compared to plastic aspherical lenses, allowing for more diverse structural options and enhancing the lens's market competitiveness. The glass aspherical lens can be made of various types of glass known to those skilled in the art; this will not be elaborated further in this embodiment.

[0039] In an optional embodiment, the first lens L1, the sixth lens L6, and the seventh lens L7 are all glass spherical lenses. The lower proportion of glass lenses used in the zoom lens allows for a smaller overall size and also helps reduce the cost.

[0040] Based on the above embodiment, 1.437≤nd4≤1.640; where nd4 is the refractive index of the fourth lens L4.

[0041] Specifically, the fourth lens L4 is a glass aspherical lens, which combines the high and low temperature stability of glass lenses with the aberration correction capability of plastic lenses. After light passes through the aperture STO, it first passes through the fourth lens L4, which can prevent excessive and difficult-to-eliminate advanced aberrations and chromatic aberrations from appearing at the end of the lens. By setting the refractive index of the fourth lens L4 within the above range, it is beneficial to ensure the high and low temperature performance of the lens while improving the lens image quality, so as to meet the needs of use in complex environments.

[0042] Optionally, the sixth lens L6 and the seventh lens L7 form a cemented lens group with a power of 0.008 ≤ F67 / F2 ≤ 0.140; where F67 represents the optical power of the cemented lens group formed by the sixth lens L6 and the seventh lens L7, and F2 is the optical power of the zoom lens group G2.

[0043] Specifically, using a cemented lens after the STO aperture can reduce chromatic aberration by leveraging the complementary chromatic aberration of the positive and negative optical power surfaces of the cemented lens. Simultaneously, the remaining chromatic aberration is used to balance chromatic aberration caused by other components of the zoom lens. This allows for the full correction of various aberrations in the zoom lens, improving imaging performance. Under a compact structure, it can increase resolution, optimize optical performance such as distortion, and reduce light loss caused by inter-lens reflections, thereby improving illumination and ultimately enhancing image quality and sharpness. Furthermore, by cementing the sixth lens (L6) and the seventh lens (L7), the air gap between them can be effectively reduced, further decreasing the overall lens length.

[0044] For example, during zooming, lenses covering a wide spectral range are prone to axial chromatic aberration and magnification chromatic aberration. Cemented lenses effectively compensate for these two types of chromatic aberration. By combining the positive and negative powers of the glass lenses, chromatic aberration can be efficiently suppressed, avoiding image problems such as color cast during zooming. In addition, compared to using a single lens element, cemented lenses can integrate multiple lenses into a single lens unit, reducing the overall length of the lens while ensuring lens centering and consistency. Aspherical lenses can effectively improve the monochromatic aberration of a lens. When combined with cemented lenses, they can achieve goals such as full-spectrum, full-zoom-range chromatic aberration correction, extremely compact size, stable zooming, and controllable cost, meeting the needs of use in various complex environments.

[0045] Optionally, 3.380 ≤ L / FW ≤ 3.620; where L represents the maximum distance from the center of the aperture stop STO to the object-side surface of the first lens L1 during zooming, and FW represents the focal length of the zoom lens at the wide-angle end. This minimizes the risk of abrupt aberrations in the zoom lens, compressing the overall lens length while maintaining performance, ensuring consistency across the entire zoom range. This allows it to meet the all-weather requirements of security applications, including "wide-angle panoramic monitoring and telephoto detail recognition," and fulfills usage needs in various complex environments.

[0046] Optionally, FT / FW ≤ 2.400; where FW represents the focal length of the zoom lens at the wide-angle end, and FT represents the focal length of the zoom lens at the telephoto end. By controlling the ratio of the focal length at the wide-angle end to that at the telephoto end, the zoom range and focal length range of the zoom lens can be controlled to meet the usage needs under more conditions.

[0047] Optionally, 0.105≤S1 / TTL≤0.116, 0.150≤S2 / TTL≤0.160; where S1 represents the maximum distance that the focusing lens group G1 can move, S2 represents the maximum distance that the zoom lens group G2 can move, and TTL represents the distance from the vertex of the object side of the first lens L1 to the image plane when the zoom lens is at the wide-angle end.

[0048] Specifically, S1 represents the distance between the closest and farthest positions of the focusing lens group G1 and the image plane during its movement, and S2 represents the distance between the closest and farthest positions of the zoom lens group G2 and the image plane during its movement. TTL represents the total length of the optical system at the wide-angle end of the zoom lens, which is the longest during the entire zoom process. By controlling the movement range of the focusing lens group G1 and the zoom lens group G2, the complete coverage of the preset zoom range can be ensured, the spatial constraints of adapting to short total length conditions can be met, and image plane shift during zooming can be suppressed, the load and error of the drive mechanism can be reduced, and the image clarity in all scenes can be guaranteed. This achieves optimal system-level performance and can adapt to the clear imaging requirements of the security field across "all focal lengths, all scenes, and all environments," meeting the usage needs in different complex environments.

[0049] This invention provides a two-element zoom lens that uses only nine lenses to achieve full-band confocal focusing under a 1 / 2.7″ target surface and in the 436nm-850nm wavelength range. It also features a larger aperture and higher image quality, making it suitable for a wider range of usage needs.

[0050] In one exemplary embodiment, Table 1 details a feasible implementation. Figure 1 and Figure 2 The specific parameters of the zoom lens shown are as follows.

[0051] Table 1. Parameter Design of a Zoom Lens Table 2 shows the design parameters of a zoom lens corresponding to Table 1, including lens surface type, radius of curvature, thickness, and materials.

[0052] Table 2. Design of optical physical parameters for zoom lenses. In Table 2, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens. The radius of curvature represents the curvature of the corresponding lens surface in mm. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface in mm. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the ability of the material between the current surface and the next surface to disperse light. A blank space indicates that the current position is air and the Abbe number is 1.

[0053] Table 3 shows the design parameters for the zoom interval at the wide-angle and telephoto ends of a zoom lens corresponding to Table 2.

[0054] Table 3. A zoom interval design for the wide-angle and telephoto ends of zoom lenses. Table 4 shows the aspheric coefficient values ​​used in the current embodiment.

[0055] Table 4 Aspherical coefficients of a zoom lens The k values ​​in Table 4 represent the numerical values ​​of the best-fit conic coefficients for the aspheric surface. The conic coefficients of the aspheric surface can be defined using the following aspheric formula, but are not limited to the following representations: ; Where z is the axial sagitta of the aspherical surface in the Z direction, that is, the axial distance from the vertex of the surface at a position perpendicular to the optical axis and at a height of r along the optical axis; r is the height of the aspherical surface; c is the curvature of the fitted sphere, that is, the curvature at the vertex of the aspherical surface, which is numerically the reciprocal of the radius of curvature; k is the fitted conic coefficient. , , , , , These are the aspherical coefficients of the 4th, 6th, 8th, 10th, 12th, and 14th orders of the aspherical polynomial, respectively. The terms are combined to form higher-order terms of the corresponding aspherical surface, where i is a positive even number.

[0056] Based on the above parameter design, Table 5 shows the lens parameters of the zoom lens implemented in this embodiment.

[0057] Table 5 Lens parameters of a zoom lens Figure 3 yes Figure 1 The diagram shown is a transverse chromatic aberration image at the wide-angle end of the zoom lens. Figure 3 The diagram shows the transverse chromatic aberration curves for wavelengths of 436nm, 486nm, 546nm, 587nm, and 656nm. The vertical direction represents the field of view, with 0 indicating the optical axis. The vertex in the transverse direction represents the maximum image height. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 3 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the wide-angle end, which can meet the application requirements under normal conditions.

[0058] Figures 4 to 9 yes Figure 1 The aperture fan diagram at the wide-angle end of the zoom lens shown is as follows: Figures 4 to 9 As shown, the horizontal axis represents the normalized beam aperture, and the vertical axis represents the transverse aberration. The fan plot is one of the most commonly used evaluation methods in modern optical design. Ideally, each curve completely coincides with the horizontal axis; at this point, all rays in the field of view are focused at the same point on the image plane. The interval corresponding to the vertical axis of the curve represents the maximum dispersion range of the beam on the ideal image plane. The fan plot can reflect not only monochromatic aberrations of different wavelengths but also the magnitude of transverse chromatic aberration. Figures 4 to 9 It can be seen that, at the wide-angle end, all wavelengths of the zoom lens closely approximate the horizontal axis, indicating that the transverse aberration of each wavelength is well corrected. Simultaneously, the curves for each wavelength show no significant dispersion, indicating that the zoom lens also effectively corrects chromatic aberration, achieving high-resolution imaging and meeting the usage requirements of zoom lenses. Figure 4 yes Figure 1 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end when the object plane is 0.00 degrees. Figure 5 yes Figure 1 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 17.96 degrees. Figure 6 yes Figure 1 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 30.38 degrees. Figure 7 yes Figure 1 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 51.07 degrees. Figure 8 yes Figure 1 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane of 69.00 degrees. Figure 9 yes Figure 1 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 76.47 degrees. Figures 4 to 9 Curves for light with wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm are shown, with a maximum scaling of ±100.000 μm.

[0059] Figure 10 yes Figure 1 The diagram shown depicts the axial aberrations at the wide-angle end of a zoom lens. Figure 10 The diagram shows axial aberration curves for wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm. The vertical direction represents the normalized aperture, with 0 indicating the optical axis. The vertex in the perpendicular direction represents the maximum pupil radius, which is 1.2480 mm. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 4It can be seen that the axial aberrations of different wavelengths are controlled within a reasonable range throughout the normalized aperture. There is no obvious color difference between visible light and infrared light, and a clear image can be formed across the entire wavelength range.

[0060] Figure 11 yes Figure 2 The diagram shown is a transverse chromatic aberration image at the telephoto end of the zoom lens. Figure 11 The diagram shows the transverse chromatic aberration curves for wavelengths of 436nm, 486nm, 546nm, 587nm, and 656nm. The vertical direction represents the field of view, with 0 indicating the optical axis. The vertex in the transverse direction represents the maximum image height. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 11 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the telephoto end, which can meet the application requirements under normal conditions.

[0061] Figures 12 to 17 yes Figure 2 The aperture fan diagram shown is from the telephoto end of the zoom lens. Figures 12 to 17 It can be seen that, at the telephoto end, all wavelengths of the zoom lens closely approximate the horizontal axis in each field of view, indicating that the transverse aberration of each wavelength is well corrected. Simultaneously, the curves for each wavelength do not show significant dispersion, indicating that the zoom lens also effectively corrects chromatic aberration, achieving high-resolution imaging and meeting the usage requirements of zoom lenses. Among these, Figure 12 yes Figure 2 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with the object plane at 0.00 degrees. Figure 13 yes Figure 2 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 7.62 degrees. Figure 14 yes Figure 2 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 12.69 degrees. Figure 15 yes Figure 2 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 20.31 degrees. Figure 16 yes Figure 2 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 25.40 degrees. Figure 17 yes Figure 2 The image shown is a fan-shaped pattern of the zoom lens at its telephoto end with an object plane angle of 26.92 degrees. Figures 12 to 17 Curves for light with wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm are shown, with a maximum scaling of ±100.000 μm.

[0062] Figure 18 yes Figure 2 The diagram shown is an axial aberration map at the telephoto end of a zoom lens. Figure 18 The diagram shows axial aberration curves for wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm. The vertical direction represents the normalized aperture, with 0 indicating the optical axis. The vertex in the perpendicular direction represents the maximum pupil radius, which is 1.5993 mm. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 18 It can be seen that the axial aberrations of different wavelengths are controlled within a reasonable range throughout the normalized aperture. There is no obvious color difference between visible light and infrared light, and a clear image can be formed across the entire wavelength range.

[0063] In another exemplary embodiment, Figure 19 This is a schematic diagram of another zoom lens at the wide-angle end provided in an embodiment of the present invention. Figure 20 This is a schematic diagram of another zoom lens at the telephoto end provided in an embodiment of the present invention. Table 6 details another feasible implementation. Figure 19 and Figure 20 The specific parameters of the zoom lens shown are as follows.

[0064] Table 6. Another parameter design for zoom lenses Table 7 shows the design parameters of a zoom lens, including lens surface type, radius of curvature, thickness, and materials, corresponding to those in Table 6.

[0065] Table 7. Another optical physical parameter design for zoom lenses In Table 7, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens. The radius of curvature represents the curvature of the corresponding lens surface in mm. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface in mm. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the ability of the material between the current surface and the next surface to disperse light. A blank space indicates that the current position is air and the Abbe number is 1.

[0066] Table 8 shows the design parameters for the zoom interval at the wide-angle and telephoto ends of a zoom lens corresponding to Table 7.

[0067] Table 8. Alternative zoom interval design for the wide-angle and telephoto ends of zoom lenses. Table 9 shows the aspheric coefficient values ​​used in the current embodiment.

[0068] Table 9 Aspherical coefficients of another zoom lens The k values ​​in Table 9 represent the numerical values ​​of the best-fit conic coefficients for the aspheric surface. The conic coefficients of the aspheric surface can be defined using the following aspheric formula, but are not limited to the following representations: ; Where z is the axial sagitta of the aspherical surface in the Z direction, that is, the axial distance from the vertex of the surface at a position perpendicular to the optical axis and at a height of r along the optical axis; r is the height of the aspherical surface; c is the curvature of the fitted sphere, that is, the curvature at the vertex of the aspherical surface, which is numerically the reciprocal of the radius of curvature; k is the fitted conic coefficient. , , , , , These are the aspherical coefficients of the 4th, 6th, 8th, 10th, 12th, and 14th orders of the aspherical polynomial, respectively. The terms are combined to form higher-order terms of the corresponding aspherical surface, where i is a positive even number.

[0069] Based on the above parameter design, Table 10 shows the lens parameters of the zoom lens implemented in this embodiment.

[0070] Table 10 Lens parameters of another zoom lens Figure 21 yes Figure 19 The diagram shown is a transverse chromatic aberration image at the wide-angle end of the zoom lens. Figure 21 The diagram shows the transverse chromatic aberration curves for wavelengths of 436nm, 486nm, 546nm, 587nm, and 656nm. The vertical direction represents the field of view, with 0 indicating the optical axis. The vertex in the transverse direction represents the maximum image height. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 21 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the wide-angle end, which can meet the application requirements under normal conditions.

[0071] Figures 22 to 27 yes Figure 19 The aperture fan diagram shown is from the wide-angle end of the zoom lens. Figures 22 to 27It can be seen that, at the wide-angle end, all wavelengths of the zoom lens closely approximate the horizontal axis, indicating that the transverse aberration of each wavelength is well corrected. Simultaneously, the curves for each wavelength show no significant dispersion, indicating that the zoom lens also effectively corrects chromatic aberration, achieving high-resolution imaging and meeting the usage requirements of zoom lenses. Figure 22 yes Figure 19 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end when the object plane is 0.00 degrees. Figure 23 yes Figure 19 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 17.96 degrees. Figure 24 yes Figure 19 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 30.38 degrees. Figure 25 yes Figure 19 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 51.07 degrees. Figure 26 yes Figure 19 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane of 69.00 degrees. Figure 27 yes Figure 19 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 76.47 degrees. Figures 22 to 27 Curves for light with wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm are shown, with a maximum scaling of ±100.000 μm.

[0072] Figure 28 yes Figure 19 The diagram shown depicts the axial aberrations at the wide-angle end of a zoom lens. Figure 28 The diagram shows axial aberration curves for wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm. The vertical direction represents the normalized aperture, with 0 indicating the optical axis. The vertex in the perpendicular direction represents the maximum pupil radius, which is 1.2392 mm. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 28 It can be seen that the axial aberrations of different wavelengths are controlled within a reasonable range throughout the normalized aperture. There is no obvious color difference between visible light and infrared light, and a clear image can be formed across the entire wavelength range.

[0073] Figure 29 yes Figure 20 The diagram shown is a transverse chromatic aberration image at the telephoto end of the zoom lens. Figure 29The diagram shows the transverse chromatic aberration curves for wavelengths of 436nm, 486nm, 546nm, 587nm, and 656nm. The vertical direction represents the field of view, with 0 indicating the optical axis. The vertex in the transverse direction represents the maximum image height. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 29 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the telephoto end, which can meet the application requirements under normal conditions.

[0074] Figures 30 to 35 yes Figure 20 The aperture fan diagram shown is from the telephoto end of the zoom lens. Figures 30 to 35 It can be seen that, at the telephoto end, all wavelengths of the zoom lens closely approximate the horizontal axis in each field of view, indicating that the transverse aberration of each wavelength is well corrected. Simultaneously, the curves for each wavelength do not show significant dispersion, indicating that the zoom lens also effectively corrects chromatic aberration, achieving high-resolution imaging and meeting the usage requirements of zoom lenses. Among these, Figure 30 yes Figure 20 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with the object plane at 0.00 degrees. Figure 31 yes Figure 20 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 7.62 degrees. Figure 32 yes Figure 20 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 12.69 degrees. Figure 33 yes Figure 20 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 20.31 degrees. Figure 34 yes Figure 20 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 25.40 degrees. Figure 35 yes Figure 20 The image shown is a fan-shaped pattern of the zoom lens at its telephoto end with an object plane angle of 26.92 degrees. Figures 30 to 35 Curves for light with wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm are shown, with a maximum scaling of ±100.000 μm.

[0075] Figure 36 yes Figure 20 The diagram shown is an axial aberration map at the telephoto end of a zoom lens. Figure 36The diagram shows axial aberration curves for wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm. The vertical direction represents the normalized aperture, with 0 indicating the optical axis. The vertex in the perpendicular direction represents the maximum pupil radius, which is 1.6161 mm. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 36 It can be seen that the axial aberrations of different wavelengths are controlled within a reasonable range throughout the normalized aperture. There is no obvious color difference between visible light and infrared light, and a clear image can be formed across the entire wavelength range.

[0076] In yet another exemplary embodiment, Figure 37 This is a schematic diagram of another zoom lens at the wide-angle end provided in an embodiment of the present invention. Figure 38 This is a schematic diagram of another zoom lens at the telephoto end provided by an embodiment of the present invention. Table 11 details another feasible implementation method. Figure 37 and Figure 38 The specific parameters of the zoom lens shown are as follows.

[0077] Table 11 Another parameter design for zoom lenses Table 12 shows the design parameters of a zoom lens, including lens surface type, radius of curvature, thickness, and materials, corresponding to Table 11.

[0078] Table 12 Another optical physical parameter design for zoom lenses In Table 12, the surface numbers are assigned according to the surface sequence of each lens. For example, surface number 1 represents the object side of the first lens L1, surface number 2 represents the image side of the first lens L1, and so on. "STO" represents the aperture stop of the zoom lens. The radius of curvature represents the curvature of the corresponding lens surface in mm. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INF" indicates that the surface is flat and the radius of curvature is infinite. The thickness represents the axial distance between the current surface and the next surface in mm. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air and the refractive index is 1. The Abbe number represents the ability of the material between the current surface and the next surface to disperse light. A blank space indicates that the current position is air and the Abbe number is 1.

[0079] Table 13 shows the design parameters for the zoom interval at the wide-angle and telephoto ends of a zoom lens corresponding to Table 12.

[0080] Table 13: Another zoom interval design for the wide-angle and telephoto ends of zoom lenses. Table 14 shows the aspheric coefficient values ​​used in the current embodiment.

[0081] Table 14 Aspherical coefficients of another type of zoom lens The k values ​​in Table 14 represent the numerical values ​​of the best-fit conic coefficients for the aspheric surface. The conic coefficients of the aspheric surface can be defined using the following aspheric formula, but are not limited to the following representations: ; Where z is the axial sagitta of the aspherical surface in the Z direction, that is, the axial distance from the vertex of the surface at a position perpendicular to the optical axis and at a height of r along the optical axis; r is the height of the aspherical surface; c is the curvature of the fitted sphere, that is, the curvature at the vertex of the aspherical surface, which is numerically the reciprocal of the radius of curvature; k is the fitted conic coefficient. , , , , , These are the aspherical coefficients of the 4th, 6th, 8th, 10th, 12th, and 14th orders of the aspherical polynomial, respectively. The terms are combined to form higher-order terms of the corresponding aspherical surface, where i is a positive even number.

[0082] Based on the above parameter design, Table 15 shows the lens parameters of the zoom lens implemented in this embodiment.

[0083] Table 15 Lens parameters for another type of zoom lens Figure 39 yes Figure 37 The diagram shown is a transverse chromatic aberration image at the wide-angle end of the zoom lens. Figure 39 The diagram shows the transverse chromatic aberration curves for wavelengths of 436nm, 486nm, 546nm, 587nm, and 656nm. The vertical direction represents the field of view, with 0 indicating the optical axis. The vertex in the transverse direction represents the maximum image height. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 39 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the wide-angle end, which can meet the application requirements under normal conditions.

[0084] Figures 40 to 45 yes Figure 37 The aperture fan diagram shown is from the wide-angle end of the zoom lens. Figures 40 to 45It can be seen that, at the wide-angle end, all wavelengths of the zoom lens closely approximate the horizontal axis, indicating that the transverse aberration of each wavelength is well corrected. Simultaneously, the curves for each wavelength show no significant dispersion, indicating that the zoom lens also effectively corrects chromatic aberration, achieving high-resolution imaging and meeting the usage requirements of zoom lenses. Figure 40 yes Figure 37 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end when the object plane is 0.00 degrees. Figure 41 yes Figure 37 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 17.96 degrees. Figure 42 yes Figure 37 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 30.38 degrees. Figure 43 yes Figure 37 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 51.07 degrees. Figure 44 yes Figure 37 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane of 69.00 degrees. Figure 45 yes Figure 37 The image shown is a fan-shaped pattern of the zoom lens at the wide-angle end with an object plane angle of 76.47 degrees. Figures 40 to 45 Curves for light with wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm are shown, with a maximum scaling of ±100.000 μm.

[0085] Figure 46 yes Figure 37 The diagram shown depicts the axial aberrations at the wide-angle end of a zoom lens. Figure 46 The diagram shows axial aberration curves for wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm. The vertical direction represents the normalized aperture, with 0 indicating the optical axis. The vertex in the perpendicular direction represents the maximum pupil radius, which is 1.2878 mm. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 46 It can be seen that the axial aberrations of different wavelengths are controlled within a reasonable range throughout the normalized aperture. There is no obvious color difference between visible light and infrared light, and a clear image can be formed across the entire wavelength range.

[0086] Figure 47 yes Figure 38 The diagram shown is a transverse chromatic aberration image at the telephoto end of the zoom lens. Figure 47The diagram shows the transverse chromatic aberration curves for wavelengths of 436nm, 486nm, 546nm, 587nm, and 656nm. The vertical direction represents the field of view, with 0 indicating the optical axis. The vertex in the transverse direction represents the maximum image height. The dominant wavelength is 546nm, and the horizontal direction represents the offset relative to the dominant wavelength, in micrometers (μm). Figure 47 It can be seen that the chromatic aberration along the vertical axis is controlled within a small range for different wavelengths, indicating that the zoom lens has good control over the chromatic aberration along the vertical axis at the telephoto end, which can meet the application requirements under normal conditions.

[0087] Figures 48 to 53 yes Figure 38 The aperture fan diagram shown is from the telephoto end of the zoom lens. Figures 48 to 53 It can be seen that, at the telephoto end, all wavelengths of the zoom lens closely approximate the horizontal axis in each field of view, indicating that the transverse aberration of each wavelength is well corrected. Simultaneously, the curves for each wavelength do not show significant dispersion, indicating that the zoom lens also effectively corrects chromatic aberration, achieving high-resolution imaging and meeting the usage requirements of zoom lenses. Among these, Figure 48 yes Figure 38 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with the object plane at 0.00 degrees. Figure 49 yes Figure 38 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 7.62 degrees. Figure 50 yes Figure 38 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 12.69 degrees. Figure 51 yes Figure 38 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 20.31 degrees. Figure 52 yes Figure 38 The image shown is a fan-shaped pattern of the zoom lens at the telephoto end with an object plane angle of 25.40 degrees. Figure 53 yes Figure 38 The image shown is a fan-shaped pattern of the zoom lens at its telephoto end with an object plane angle of 26.92 degrees. Figures 48 to 53 Curves for light with wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm are shown, with a maximum scaling of ±100.000 μm.

[0088] Figure 54 yes Figure 38 The diagram shown is an axial aberration map at the telephoto end of a zoom lens. Figure 54The diagram shows axial aberration curves for wavelengths of 436 nm, 486 nm, 546 nm, 587 nm, 656 nm, and 850 nm. The vertical direction represents the normalized aperture, with 0 indicating the optical axis. The vertex in the perpendicular direction represents the maximum pupil radius, which is 1.6976 mm. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength, in millimeters (mm). Figure 54 It can be seen that the axial aberrations of different wavelengths are controlled within a reasonable range throughout the normalized aperture. There is no obvious color difference between visible light and infrared light, and a clear image can be formed across the entire wavelength range.

[0089] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A zoom lens, characterized in that, include: Along the optical axis, from the object side to the image side, a focusing lens group with negative optical power, an aperture, and a zoom lens group with positive optical power are arranged in sequence. The focusing lens group consists of a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power; The zoom lens group consists of a fourth lens with positive optical power, a fifth lens with positive optical power, a sixth lens with negative optical power, a seventh lens with positive optical power, an eighth lens with negative optical power, and a ninth lens with positive optical power. The zoom lens has two lens groups with optical power. The focusing lens group and the zoom lens group are moved along the direction of the optical axis; when the focusing lens group and the zoom lens group move together along the direction of the optical axis, the zoom lens can switch between the wide-angle end and the telephoto end.

2. The zoom lens according to claim 1, characterized in that, 1.17≤|F2 / F1|≤1.21; Wherein, F1 is the optical power of the focusing lens group; F2 is the optical power of the zoom lens group.

3. The zoom lens according to claim 1, characterized in that, 0.870≤F1m / F1≤0.910; 0.800≤F2m / F2≤1.200; Wherein, F1m represents the maximum optical power of a single lens in the focusing lens group, F2m represents the maximum optical power of a single lens in the zoom lens group, F1 is the optical power of the focusing lens group, and F2 is the optical power of the zoom lens group.

4. The zoom lens according to claim 1, characterized in that, In the focusing lens group, The object-side surface of the first lens is convex, and the image-side surface of the first lens is concave. The object-side surface of the second lens is concave, and the image-side surface of the second lens is also concave. The object-side surface of the third lens is convex, and the image-side surface of the third lens is convex. In the zoom lens group, The object-side surface of the fourth lens is convex, and the image-side surface of the fourth lens is convex. The object-side surface of the fifth lens is convex, and the image-side surface of the fifth lens is concave. The object-side surface of the sixth lens is concave, and the image-side surface of the sixth lens is also concave. The object-side surface of the seventh lens is convex, and the image-side surface of the seventh lens is convex. The object-side surface of the eighth lens is concave, and the image-side surface of the eighth lens is convex. The object-side surface of the ninth lens is convex, and the image-side surface of the ninth lens is concave.

5. The zoom lens according to claim 1, characterized in that, The second lens, the third lens, the fifth lens, the eighth lens, and the ninth lens are all plastic aspherical lenses; The fourth lens is a glass aspherical lens.

6. The zoom lens according to claim 5, characterized in that, 1.437≤nd4≤1.640; Wherein, nd4 is the refractive index of the fourth lens.

7. The zoom lens according to claim 1, characterized in that, The sixth lens and the seventh lens form a cemented lens group; 0.008≤F67 / F2≤0.140; Wherein, F67 represents the optical power of the cemented lens group composed of the sixth lens and the seventh lens, and F2 is the optical power of the zoom lens group.

8. The zoom lens according to claim 1, characterized in that, 3.380≤L / FW≤3.620; Wherein, L represents the maximum distance from the center of the aperture stop to the side surface of the first lens during zooming, and FW represents the focal length of the zoom lens at the wide-angle end.

9. The zoom lens according to claim 1, characterized in that, FT / FW ≤ 2.400; Wherein, FW represents the focal length of the zoom lens at the wide-angle end, and FT represents the focal length of the zoom lens at the telephoto end.

10. The zoom lens according to claim 1, characterized in that, 0.105≤S1 / TTL≤0.116, 0.150≤S2 / TTL≤0.160; Wherein, S1 represents the maximum distance that the focusing lens group can move, S2 represents the maximum distance that the zoom lens group can move, and TTL represents the distance from the vertex of the object side of the first lens to the image plane when the zoom lens is at the wide-angle end.

Images