Zoom lens

Abstract

The application discloses a zoom lens, which comprises a first fixed lens group, a first variable magnification lens group, a second variable magnification lens group, a focusing lens group and a second fixed lens group arranged along an optical axis from an object plane to an image plane in sequence, wherein the first fixed lens group has positive focal power, the first variable magnification lens group has negative focal power, the second variable magnification lens group has positive focal power, the focusing lens group has positive focal power, and the second fixed lens group has negative focal power. The zoom lens provided by the embodiment of the application adopts a five-group element structure, uses 16 lenses, sets the number of lenses in each lens group, and further limits the focal power matching of the lenses, so that a zoom lens with a large target surface, a large magnification, a large aperture, small distortion and small volume is realized, and the zoom lens can meet more extensive use requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to a zoom lens. Background Art

[0002] In the security field, zoom lenses have been widely used due to their advantages such as long shooting distance, continuous and rapid magnification change, and the ability to achieve good shooting effects in different usage scenarios. With the development of technology, cameras are gradually moving towards miniaturization and sophistication, which also puts more stringent requirements on mainstream zoom lenses.

[0003] At present, in order to achieve a wider range of applications, 1 / 1.8" photosensitive chips have gradually become the mainstream chips on the market. However, traditional zoom lenses usually use 1 / 2.7" chips, which are difficult to use in a wide range of environments. Traditional zoom lenses also have problems such as small aperture, small magnification, and large distortion. Summary of the Invention

[0004] The present invention provides a zoom lens to realize a zoom lens with a large target surface, a large magnification, a large aperture and small distortion.

[0005] The present invention provides a zoom lens, comprising a first fixed lens group, a first magnification lens group, a second magnification lens group, a focus lens group, and a second fixed lens group, which are arranged in sequence along an optical axis from an object plane to an image plane.

[0006] The first fixed lens group and the second fixed lens group are fixedly arranged, and the first magnification changer group, the second magnification changer group and the focus lens group are movable along the optical axis direction;

[0007] The first fixed lens group has positive optical power, the first variator group has negative optical power, the second variator group has positive optical power, the focus lens group has positive optical power, and the second fixed lens group has negative optical power;

[0008] The first fixed lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object plane to the image plane; the first lens has negative optical power, the second lens has positive optical power, the third lens has positive optical power, and the fourth lens has positive optical power;

[0009] The first zoom lens group includes a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object plane to the image plane; the fifth lens has negative optical power, the sixth lens has negative optical power, and the seventh lens has positive optical power;

[0010] The second zoom lens group includes an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object plane to the image plane; the eighth lens has positive refractive power, the ninth lens has positive refractive power, the tenth lens has positive refractive power, the eleventh lens has negative refractive power, and the twelfth lens has positive refractive power;

[0011] The focusing lens group includes a thirteenth lens and a fourteenth lens arranged in sequence from the object plane to the image plane; the thirteenth lens has positive refractive power, and the fourteenth lens has negative refractive power;

[0012] The second fixed lens group includes a fifteenth lens and a sixteenth lens arranged in sequence from the object plane to the image plane; the fifteenth lens has positive refractive power, and the sixteenth lens has negative refractive power.

[0013] Optionally, the focal length of the first fixed lens group is FG1, the focal length of the first variator group is FG2, the focal length of the second variator group is FG3, the focal length of the focus lens group is FG4, the focal length of the second fixed lens group is FG5, and the focal length of the zoom lens at the wide-angle end is FW, wherein:

[0014] 4.694≤FG1 / FW≤8.151;

[0015] -1.547≤FG2 / FW≤-0.974;

[0016] 2.529≤FG3 / FW≤4.201;

[0017] 3.044≤FG4 / FW≤5.357;

[0018] -43.192≤FG5 / FW≤-4.032.

[0019] Optionally, the first lens and the second lens form a first cemented lens group;

[0020] The tenth lens and the eleventh lens form a second cemented lens group;

[0021] The thirteenth lens and the fourteenth lens form a third cemented lens group.

[0022] Optionally, the first lens and the second lens form a first cemented lens group;

[0023] The focal length of the first lens is F1, and the focal length of the first cemented lens group is F101, wherein 0.428≤|F1 / F101|≤0.628.

[0024] Optionally, the first lens and the second lens form a first cemented lens group;

[0025] The focal length of the first cemented lens group is F101, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT;

[0026] Among them, 14.625≤|F101 / (FT / FW)|≤21.419.

[0027] Optionally, the sixth lens, the twelfth lens, and the sixteenth lens are all glass aspherical lenses;

[0028] The refractive index of the sixth lens is Nd1, and the Abbe number is Vd1; the refractive index of the twelfth lens is Nd2, and the Abbe number is Vd2; the refractive index of the sixteenth lens is Nd3, and the Abbe number is Vd3;

[0029] in:

[0030] 1.45≤Nd1≤1.56;54.00≤Vd1≤96.00;

[0031] 1.45≤Nd2≤1.55;34.00≤Vd2≤95.00;

[0032] 1.78≤Nd3≤1.86;20.00≤Vd3≤95.00.

[0033] Optionally, the total optical length of the zoom lens is TTL, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT;

[0034] Among them, 10.506≤TTL / FW≤18.454, 0.792≤TTL / FT≤0.999.

[0035] Optionally, the maximum movable distance of the first zoom lens group is D2, the maximum movable distance of the second zoom lens group is D3, the maximum movable distance of the focus lens group is D4, and the total optical length of the zoom lens is TTL; wherein, 0.256≤D2 / TTL≤0.272, 0.042≤D3 / TTL≤0.082, and 0.037≤D4 / TTL≤0.056.

[0036] Optionally, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT;

[0037] Among them, 13.055≤FT / FW≤19.723.

[0038] Optionally, the focal length of the zoom lens at the wide-angle end is FW, and the optical distortion of the zoom lens at the wide-angle end is DIS1; the focal length of the zoom lens at the telephoto end is FT, and the optical distortion of the zoom lens at the telephoto end is DIS2;

[0039] Among them, 0.356≤|FW / DIS1|≤1.875, 14.167≤|FT / DIS2|≤113.535.

[0040] The zoom lens provided in an embodiment of the present invention adopts a five-element structure and uses 16 lenses. By adjusting the number of lenses in the five lens groups and further limiting the optical power combination of the five lens groups and the 16 lenses, the zoom lens has a total optical length (TTL) of TTL ≤ 100mm and a focal length (F) of 6mm ≤ F ≤ 110mm on a 1 / 1.8" target surface. Furthermore, in the 436nm to 656nm wavelength band, the zoom lens can achieve a magnification of nearly 20x, an F / # of 1.5, and distortion of less than 10%. This achieves a zoom lens with a large target surface, high magnification, large aperture, low distortion, and a compact size, meeting a wider range of application requirements.

[0041] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A schematic structural diagram of a zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0044] Figure 2 A schematic structural diagram of a zoom lens at the telephoto end provided by an embodiment of the present invention;

[0045] Figure 3 A schematic structural diagram of another zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0046] Figure 4 A schematic structural diagram of another zoom lens at the telephoto end provided by an embodiment of the present invention;

[0047] Figure 5 A schematic structural diagram of another zoom lens at the wide-angle end provided by an embodiment of the present invention;

[0048] Figure 6 A schematic structural diagram of another zoom lens at the telephoto end provided by an embodiment of the present invention;

[0049] Figure 7 This is a field curvature distortion diagram of the zoom lens provided in Example 1 of the present invention at the wide-angle end;

[0050] Figure 8 This is a field curvature distortion diagram of the zoom lens provided in Example 1 of the present invention at the telephoto end;

[0051] Figure 9 This is a ray fan diagram of the zoom lens provided in the first embodiment of the present invention at the wide-angle end;

[0052] Figure 10 A ray fan diagram of the zoom lens at the telephoto end provided by the first embodiment of the present invention;

[0053] Figure 11 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 1 of the present invention at the wide-angle end;

[0054] Figure 12 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 1 of the present invention at the telephoto end;

[0055] Figure 13 This is a diagram of field curvature distortion at the wide-angle end of the zoom lens provided in the second embodiment of the present invention;

[0056] Figure 14 This is a diagram of field curvature distortion at the telephoto end of the zoom lens provided in the second embodiment of the present invention;

[0057] Figure 15 This is a ray fan diagram of the zoom lens provided in the second embodiment of the present invention at the wide-angle end;

[0058] Figure 16 A ray fan diagram of the zoom lens at the telephoto end provided by the second embodiment of the present invention;

[0059] Figure 17 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 2 of the present invention at the wide-angle end;

[0060] Figure 18 A diagram of vertical axial chromatic aberration of the zoom lens provided in the second embodiment of the present invention at the telephoto end;

[0061] Figure 19 This is a diagram of field curvature distortion at the wide-angle end of the zoom lens provided in Example 3 of the present invention;

[0062] Figure 20 This is a diagram of field curvature distortion at the telephoto end of the zoom lens provided in the third embodiment of the present invention;

[0063] Figure 21 This is a ray fan diagram of the zoom lens at the wide-angle end provided by the third embodiment of the present invention;

[0064] Figure 22 This is a ray fan diagram of the zoom lens at the telephoto end provided by the third embodiment of the present invention;

[0065] Figure 23 A diagram of vertical axial chromatic aberration of the zoom lens provided in Example 3 of the present invention at the wide-angle end;

[0066] Figure 24 This is a diagram of vertical axis chromatic aberration of the zoom lens provided in Example 3 of the present invention at the telephoto end. DETAILED DESCRIPTION

[0067] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0068] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0069] Figure 1 This is a schematic structural diagram of a zoom lens at the wide-angle end provided by an embodiment of the present invention. Figure 2 A schematic structural diagram of a zoom lens at the telephoto end provided by an embodiment of the present invention; Figure 3 This is a schematic structural diagram of another zoom lens at the wide-angle end provided by an embodiment of the present invention. Figure 4 A schematic structural diagram of another zoom lens at the telephoto end provided by an embodiment of the present invention; Figure 5 A schematic structural diagram of another zoom lens at the wide-angle end provided by an embodiment of the present invention is shown. Figure 6 A structural diagram of another zoom lens at the telephoto end provided by an embodiment of the present invention; Figures 1-6As shown, the zoom lens provided by the embodiment of the present invention includes a first fixed lens group G1, a first magnification lens group G2, a second magnification lens group G3, a focus lens group G4 and a second fixed lens group G5 arranged in sequence along the optical axis from the object plane to the image plane.

[0070] The first fixed lens group G1 and the second fixed lens group G5 are fixed, and the first magnification lens group G2, the second magnification lens group G3 and the focus lens group G4 are movable along the optical axis.

[0071] The first fixed lens group G1 has positive refractive power, the first variator group G2 has negative refractive power, the second variator group G3 has positive refractive power, the focus lens group G4 has positive refractive power, and the second fixed lens group G5 has negative refractive power.

[0072] The first fixed lens group G1 includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4, arranged in order from the object plane to the image plane; the first lens L1 has negative refractive power, the second lens L2 has positive refractive power, the third lens L3 has positive refractive power, and the fourth lens L4 has positive refractive power.

[0073] The first zoom lens group G2 includes a fifth lens L5, a sixth lens L6, and a seventh lens L7 arranged in sequence from the object plane to the image plane; the fifth lens L5 has negative refractive power, the sixth lens L6 has negative refractive power, and the seventh lens L7 has positive refractive power.

[0074] The second zoom lens group G3 includes an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, and a twelfth lens L12, arranged in order from the object plane to the image plane. The eighth lens L8 has positive refractive power, the ninth lens L9 has positive refractive power, the tenth lens L10 has positive refractive power, the eleventh lens L11 has negative refractive power, and the twelfth lens L12 has positive refractive power.

[0075] The focusing lens group G4 includes a thirteenth lens L13 and a fourteenth lens L14 arranged in sequence from the object plane to the image plane. The thirteenth lens L13 has positive refractive power, and the fourteenth lens L14 has negative refractive power.

[0076] The second fixed lens group G5 includes a fifteenth lens L15 and a sixteenth lens L16 arranged in sequence from the object plane to the image plane; the fifteenth lens L15 has positive refractive power, and the sixteenth lens L16 has negative refractive power.

[0077] Specifically, such as Figures 1-6As shown, the zoom lens provided by the embodiment of the present application sequentially arranges, along the optical axis from the object side to the image side, a first fixed lens group G1 with positive optical power, a first variable lens group G2 with negative optical power, a second variable lens group G3 with positive optical power, a focusing lens group G4 with positive optical power, and a second fixed lens group G5 with negative optical power.

[0078] The first fixed lens group G1, the first variable lens group G2, the second variable lens group G3, the focusing lens group G4, and the second fixed lens group G5 can be arranged in one lens barrel (not shown in the figure), but are not limited thereto.

[0079] Further, the first fixed lens group G1 and the second fixed lens group G5 can be fixed in position in the lens barrel, so that the first fixed lens group G1 and the second fixed lens group G5 are immovable relative to the image plane.

[0080] The first variable lens group G2, the second variable lens group G3, and the focusing lens group G4 can reciprocally move along the optical axis in the lens barrel, wherein moving the first variable lens group G2 and the second variable lens group G3 can serve to zoom, and moving the focusing lens group G4 can serve to focus; by changing the positions of the first variable lens group G2, the second variable lens group G3, and the focusing lens group G4 along the optical axis, the zoom lens can switch between the wide-angle end and the telephoto end.

[0081] In the process of zooming by changing the positions of the first variable lens group G2, the second variable lens group G3, and the focusing lens group G4 along the optical axis, the zoom lens is at the wide-angle end when the focal length is the shortest, and is at the telephoto end when the focal length is the longest; at the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical powers.

[0082] Specifically, the optical power is equal to the difference between the image-side beam convergence degree and the object-side beam convergence degree, and represents the ability of an optical system to bend light rays. The greater the absolute value of the optical power, the stronger the ability to bend light rays, and the smaller the absolute value of the optical power, the weaker the ability to bend light rays. When the optical power is positive, the refraction of light rays is convergent; when the optical power is negative, the refraction of light rays is divergent. The optical power can be used to represent a certain refractive surface of a lens (i.e., one surface of the lens), can be used to represent a certain lens, or can be used to represent a system (i.e., a lens group) formed by multiple lenses.

[0083] In an embodiment of the present invention, the optical focal length of the first fixed lens group G1 is positive, which can converge the light to a certain extent; the optical focal length of the first magnification lens group G2 is negative, so that after the light is initially converged by the first fixed lens group G1, it is appropriately diverged by the first magnification lens group G2 to adjust the light path, ensure that the light can enter the subsequent structure, and better control the degree of light contraction in the subsequent structure to adapt to different focal length requirements.

[0084] Furthermore, the first fixed lens group G1, the first zoom lens group G2, the second zoom lens group G3, the focusing lens group G4 and the second fixed lens group G5 adopt a positive-negative-positive-positive-negative optical focal length combination, so that light can be reasonably converged and diverged when passing through each lens group, ensuring that the light will not be excessively deflected and will pass smoothly through the entire lens system. This arrangement can not only achieve a longer focal length, but also maintain good imaging quality at different focal lengths.

[0085] Continue to refer Figures 1-6 The number of lenses with optical focal length in the first fixed lens group G1 can be 4, wherein the first fixed lens group G1 can be composed of a first lens L1 with negative optical focal length, a second lens L2 with positive optical focal length, a third lens L3 with positive optical focal length, and a fourth lens L4 with positive optical focal length.

[0086] The number of lenses with optical power in the first zoom lens group G2 can be 3, wherein the first zoom lens group G2 can be composed of a fifth lens L5 with negative optical power, a sixth lens L6 with negative optical power, and a seventh lens L7 with positive optical power.

[0087] The number of lenses with optical focal length in the second zoom lens group G3 can be 5, wherein the second zoom lens group G3 can be composed of an eighth lens L8 with positive optical focal length, a ninth lens L9 with positive optical focal length, a tenth lens L10 with positive optical focal length, an eleventh lens L11 with negative optical focal length, and a twelfth lens L12 with positive optical focal length.

[0088] Among them, the second zoom lens group G3 can help correct chromatic aberration and other aberrations more finely by using a larger number of lenses (5 lenses), thereby improving image quality.

[0089] The number of lenses with optical power in the focus lens group G4 may be two, wherein the focus lens group G4 may be composed of a thirteenth lens L13 with positive optical power and a fourteenth lens L14 with negative optical power.

[0090] Focus lens group G4 utilizes a smaller number of lenses (two lenses), which helps improve focusing performance and sensitivity. For example, using only two lenses makes focus lens group G4 lighter, reducing its inertia and enabling it to move quickly and accurately to the correct position. This improves focus response speed, sensitivity, and accuracy.

[0091] At the same time, the focus lens group G4 helps reduce the manufacturing cost and complexity of the zoom lens by using a smaller number of lenses.

[0092] The number of lenses with optical power in the second fixed lens group G5 may be two, wherein the second fixed lens group G5 may consist of a fifteenth lens L15 with positive optical power and a sixteenth lens L16 with negative optical power.

[0093] In an embodiment of the present invention, a five-element structure is adopted, using 16 lenses. By adjusting the number of lenses in the five lens groups and further limiting the optical power combination of the five lens groups and the 16 lenses, the zoom lens is able to meet the following conditions: TTL ≤ 100mm, focal length F ≤ 6mm ≤ F ≤ 110mm, and magnification of nearly 20x, F / # 1.5, and distortion of less than 10% in the 436nm to 656nm wavelength band. This realizes a zoom lens with a large target surface, high magnification, large aperture, low distortion, and compact size, which can meet a wider range of application requirements.

[0094] As a feasible implementation method, continue to refer to Figures 1-6 In the first fixed lens group G1, the object-side surface of the first lens L1 is convex; the object-side surface of the second lens L2 is convex, and the image-side surface is concave; the object-side surface of the third lens L3 is convex, and the image-side surface is concave; the object-side surface of the fourth lens L4 is convex, and the image-side surface is concave.

[0095] In the first zoom lens group G2, the fifth lens L5 has a convex object-side surface and a concave image-side surface; the sixth lens L6 has a concave object-side surface and a concave image-side surface; and the seventh lens L7 has a convex object-side surface and a convex image-side surface.

[0096] In the second zoom lens group G3, the object-side surface of the eighth lens L8 is convex, and the image-side surface is convex; the object-side surface of the ninth lens L9 is convex, and the image-side surface is concave; the object-side surface of the tenth lens L10 is convex; the object-side surface of the eleventh lens L11 is convex, and the image-side surface is concave; and the object-side surface of the twelfth lens L12 is convex, and the image-side surface is concave.

[0097] In the focusing lens group G4 , the object-side surface of the thirteenth lens L13 is convex; the object-side surface of the fourteenth lens L14 is concave, and the image-side surface is convex.

[0098] In the second fixed lens group G5 , the object-side surface and the image-side surface of the fifteenth lens L15 are convex; the object-side surface and the image-side surface of the sixteenth lens L16 are concave.

[0099] Among them, the surface shape of the lens affects the propagation direction of light and determines how the light bends when passing through the lens, which in turn affects the maximum aperture and light transmittance of the lens, as well as the quality and characteristics of the imaging.

[0100] In this embodiment, by rationally matching the surface shapes of the various lenses, the optical power requirements of each lens are met, achieving the desired optical performance indicators (such as a large target area, large magnification, large aperture, low distortion, and small size), while further reducing the overall optical length of the entire zoom lens, thereby achieving a miniaturized lens design. Furthermore, while ensuring a large aperture, the path of light passing through the entire zoom lens is smoother, reducing unnecessary reflections and absorption. This helps improve light throughput and image quality while achieving a long focal length.

[0101] Continue to refer Figures 1-6 As a feasible implementation manner, the zoom lens further includes an aperture STO, which is located in the optical path between the seventh lens L7 and the eighth lens L8.

[0102] Among them, the aperture STO is set in the optical path between the seventh lens L7 and the eighth lens L8, so that the aperture STO can be closer to the front end of the zoom lens, so that the aperture STO can control the distribution of light entering the subsequent lenses to optimize aberrations such as astigmatism and coma, so that high-order aberrations are well controlled at the front end of the zoom lens, ensuring that the image height is increased and the target surface is expanded at the rear end of the zoom lens while also having good imaging quality, thereby meeting the usage requirements in more situations.

[0103] Continue to refer Figures 1-6 As a feasible implementation, the zoom lens may further include a flat glass P, which is located on the image-side surface of the sixteenth lens L16. The flat glass P can protect the photosensitive chip, thereby ensuring the imaging effect of the zoom lens. The photosensitive chip is used to convert the light signal collected by the zoom lens into an electrical signal, which can then be processed into a digital image or video through a series of processing steps.

[0104] Continue to refer Figures 1-6As a feasible implementation, the focal length of the first fixed lens group G1 is FG1, the focal length of the first variator group G2 is FG2, the focal length of the second variator group G3 is FG3, the focal length of the focus lens group G4 is FG4, the focal length of the second fixed lens group G5 is FG5, and the focal length of the zoom lens at the wide-angle end is FW, wherein 4.694≤FG1 / FW≤8.151; -1.547≤FG2 / FW≤-0.974; 2.529≤FG3 / FW≤4.201; 3.044≤FG4 / FW≤5.357; and -43.192≤FG5 / FW≤-4.032.

[0105] Among them, by further limiting the focal length of each lens group, a reasonable combination of the optical power of each lens can be achieved, allowing light to pass through the zoom lens more smoothly, thereby correcting the high-level aberrations of the zoom lens to a greater extent. While achieving a longer focal length, it can also maintain good image quality at different focal lengths.

[0106] Continue to refer Figures 1-6 As a feasible implementation manner, the first lens L1 and the second lens L2 form a first cemented lens group g1; the tenth lens L10 and the eleventh lens L11 form a second cemented lens group g2; the thirteenth lens L13 and the fourteenth lens L14 form a third cemented lens group g3.

[0107] Among them, such as Figures 1-6 As shown, cementing the first lens L1 and the second lens L2, the tenth lens L10 and the eleventh lens L11, and the tenth lens L10 and the eleventh lens L11 can minimize or eliminate chromatic aberration, ensuring that the chromatic aberration of the zoom lens is fully corrected. At the same time, the air gaps between the first lens L1 and the second lens L2, the tenth lens L10 and the eleventh lens L11, and the tenth lens L10 and the eleventh lens L11 can be effectively reduced, further shortening the overall optical length of the lens.

[0108] Furthermore, cementing the first lens L1 and the second lens L2, the tenth lens L10 and the eleventh lens L11, and the tenth lens L10 and the eleventh lens L11 can reduce air interfaces, thereby reducing reflection losses. Furthermore, the number of assembly components between the first lens L1 and the second lens L2, the tenth lens L10 and the eleventh lens L11, and the tenth lens L10 and the eleventh lens L11 can be reduced, thereby simplifying the assembly process during lens manufacturing and reducing costs. Furthermore, the impact of lens tolerances such as tilt and deflection generated during the assembly process on the zoom lens can be reduced, thereby improving the stability of the zoom lens.

[0109] Continue to refer Figures 1-6As a feasible implementation, the first lens L1 and the second lens L2 form a first cemented lens group g1; the focal length of the first lens L1 is F1, and the focal length of the first cemented lens group g1 is F101, wherein 0.428≤|F1 / F101|≤0.628.

[0110] Specifically, the first lens L1 and the second lens L2 are cemented together to form a first cemented lens group g1 with positive refractive power, which can better correct chromatic aberration while ensuring that light can enter the subsequent structure.

[0111] Furthermore, when light passes through the first cemented lens group g1, if the focal length of the first lens L1 is too long, the light will become too scattered before entering the subsequent lenses, resulting in a decrease in imaging quality.

[0112] In this embodiment, the focal length F101 of the first cemented lens group g1 and the focal length F1 of the first lens L1 are set to satisfy 0.428≤|F1 / F101|≤0.628, ensuring that the focal length of the first lens L1 is moderate. This allows the object-side light to be more smoothly introduced into the imaging system, reduces the abrupt changes in the light in the subsequent lens groups, and thus enables correction of higher-order aberrations to a greater extent.

[0113] Continue to refer Figures 1-6 As a feasible implementation, the first lens L1 and the second lens L2 form a first cemented lens group g1; the focal length of the first cemented lens group g1 is F101, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT, wherein 14.625≤|F101 / (FT / FW)|≤21.419.

[0114] Specifically, the first lens L1 and the second lens L2 are cemented together to form a first cemented lens group g1 with positive refractive power, which can better correct chromatic aberration while ensuring that light can enter the subsequent structure.

[0115] Furthermore, the focal length F101 of the first cemented lens group g1, the focal length FW of the zoom lens at the wide-angle end, and the focal length FT of the zoom lens at the telephoto end satisfy 14.625≤|F101 / (FT / FW)|≤21.419, wherein FT / FW can be understood as the zoom ratio. By limiting the ratio range between the focal length F101 of the first cemented lens group g1 and the zoom ratio FT / FW, it can be ensured that the zoom lens can achieve a higher magnification between the wide-angle end and the telephoto end (for example, the magnification can reach 20 times or more). At the same time, the light can be distributed more widely when reaching the photosensitive chip (target surface), which is beneficial to expanding the target surface size of the zoom lens.

[0116] As a feasible embodiment, the sixth lens L6, the twelfth lens L12, and the sixteenth lens L16 are all glass aspherical lenses. The refractive index of the sixth lens L6 is Nd1, and the Abbe number is Vd1; the refractive index of the twelfth lens L12 is Nd2, and the Abbe number is Vd2; the refractive index of the sixteenth lens L16 is Nd3, and the Abbe number is Vd3. Here, 1.45 ≤ Nd1 ≤ 1.56; 54.00 ≤ Vd1 ≤ 96.00; 1.45 ≤ Nd2 ≤ 1.55; 34.00 ≤ Vd2 ≤ 95.00; 1.78 ≤ Nd3 ≤ 1.86; and 20.00 ≤ Vd3 ≤ 95.00.

[0117] Specifically, the zoom lens provided by the embodiment of the present invention includes at least three glass aspherical lenses, which can correct the geometric aberrations of the zoom lens, such as spherical aberration, coma and astigmatism, to improve the imaging quality of the entire zoom lens.

[0118] Among them, at least one glass aspheric lens can be set in the first zoom lens group G2, the second zoom lens group G3 and the second fixed lens group G5, so that the spherical aberration and higher-order aberrations of the above lens groups can be better corrected, thereby improving the clarity and sharpness of the image, especially under high magnification conditions.

[0119] In this embodiment of the present invention, the sixth lens element L6, the twelfth lens element L12, and the sixteenth lens element L16 are configured as glass aspheric lenses, thereby achieving a more uniform distribution of the glass aspheric lenses within the zoom lens. The sixth lens element L6 can help correct aberrations generated during the zooming process, the twelfth lens element L12 can further correct aberrations, improving image quality, and the sixteenth lens element L16 can further correct any residual aberrations before final imaging. This effectively corrects aberrations throughout the entire zoom range, ensuring excellent image quality at all focal lengths. Furthermore, the uniform distribution of the aspheric lenses can better coordinate the optical performance of the entire lens system, reduce local aberration accumulation, and improve overall image quality.

[0120] Furthermore, the refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium. It is mainly used to describe the material's ability to refract light. Different materials have different refractive indices.

[0121] The Abbe number is an index used to represent the dispersion ability of a transparent medium. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the milder the dispersion of the medium, the larger the Abbe number.

[0122] In this embodiment, by reasonably limiting the refractive indices and Abbe numbers of the sixth lens element L6, the twelfth lens element L12, and the sixteenth lens element L16, spherical aberration and higher-order aberrations can be corrected to a greater extent, which is beneficial for eliminating distortion in the telephoto end image and maintaining the geometric shape of the image.

[0123] At the same time, since the above-mentioned aspherical lens has good aberration correction capability, it is also beneficial to reduce the total number of lenses required in the zoom lens, thereby simplifying the lens design, reducing weight, and compressing the size of the lens.

[0124] As a feasible implementation manner, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 are all glass spherical lenses.

[0125] The lens is a spherical lens, which helps to reduce costs and is easy to manufacture.

[0126] Furthermore, all lenses in the zoom lens are made of glass lenses, wherein glass lenses have higher transmittance, which can reduce the loss of light energy, so that the photosensitive chip receives more light energy, which is conducive to better imaging effects in dark environments.

[0127] At the same time, glass lenses have the advantages of high hardness, strong wear resistance, long service life and are not easily deformed by temperature, which can make the performance of zoom lenses more stable.

[0128] As a feasible implementation, the total optical length of the zoom lens is TTL, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT, wherein 10.506≤TTL / FW≤18.454, and 0.792≤TTL / FT≤0.999.

[0129] The total length TTL of the zoom lens refers to the distance from the optical axis center of the object-side surface of the first lens L1 to the image plane.

[0130] In this embodiment, by controlling the ratio of the total optical length TTL of the zoom lens to the focal length FW of the zoom lens at the wide-angle end, and the ratio of the total optical length TTL of the zoom lens to the focal length FT of the zoom lens at the telephoto end within the above-mentioned ranges, a compact design of the zoom lens can be achieved while maintaining a high magnification, thereby making the total optical length of the zoom lens smaller, which is conducive to achieving a miniaturized design of the zoom lens.

[0131] As a feasible implementation, the maximum movable distance of the first zoom lens group G2 is D2, the maximum movable distance of the second zoom lens group G3 is D3, the maximum movable distance of the focus lens group G4 is D4, and the total optical length of the zoom lens is TTL, wherein 0.256≤D2 / TTL≤0.272, 0.042≤D3 / TTL≤0.082, and 0.037≤D4 / TTL≤0.056.

[0132] Among them, the maximum movable distance D2 of the first magnification lens group G2 and the total optical length TTL of the zoom lens satisfy 0.256≤D2 / TTL≤0.272, ensuring that the first magnification lens group G2 can move effectively during the zooming process to achieve the zoom function from wide angle to telephoto. At the same time, the movement of the first magnification lens group G2 will not occupy too much of the total lens length, thereby helping to reduce the size of the lens.

[0133] The maximum movable distance D3 of the second zoom lens group G3 and the total optical length TTL of the zoom lens satisfy 0.042≤D3 / TTL≤0.082, ensuring that the second zoom lens group G3 can move effectively during the zooming process to further adjust the light path and achieve a high magnification ratio. At the same time, the movement of the second zoom lens group G3 will not occupy too much of the total lens length, thereby helping to reduce the lens size.

[0134] The maximum movable distance D4 of the focus lens group G4 and the total optical length TTL of the zoom lens satisfy 0.037≤D4 / TTL≤0.056, ensuring that the focus lens group G4 can move effectively during the focusing process to achieve fast and accurate focusing. At the same time, the movement of the focus lens group G4 does not occupy too much of the total lens length, thereby helping to reduce the lens size.

[0135] Among them, by reasonably setting the maximum movable distance of the first zoom lens group G2 and the second zoom lens group G3, the zoom lens can ensure a fast response during the zooming process, so that the zoom lens can quickly adjust the focal length during the zooming process and achieve rapid switching from wide angle to telephoto.

[0136] At the same time, by reasonably setting the maximum movable distance of the focus lens group G4, the zoom lens can ensure a quick response during the focusing process, so that the zoom lens can quickly adjust the focus during the focusing process, thereby achieving fast and accurate focusing.

[0137] In summary, in this embodiment, by limiting the maximum movable distances of the first variator lens group G2, the second variator lens group G3, and the focus lens group G4, a fast-response zoom-focus function is achieved for the zoom lens, ensuring rapid adjustment during both zooming and focusing. This also makes the zoom lens more compact, reducing its overall size.

[0138] As a feasible implementation, the focal length of the zoom lens at the wide-angle end is FW, and the focal length of the zoom lens at the telephoto end is FT, wherein 13.055≤FT / FW≤19.723.

[0139] Among them, by reasonably limiting the ratio between the focal length FW of the zoom lens at the wide-angle end and the focal length FT at the telephoto end, the zoom lens can achieve a magnification ratio close to 20 times, and while ensuring a large magnification ratio and a large target area, the distortion can be controlled within a reasonably small range, thereby better magnifying the details of the required imaging picture and maintaining a good imaging effect.

[0140] As a feasible implementation method, the focal length of the zoom lens at the wide-angle end is FW, and the optical distortion of the zoom lens at the wide-angle end is DIS1; the focal length of the zoom lens at the telephoto end is FT, and the optical distortion of the zoom lens at the telephoto end is DIS2; wherein, 0.356≤|FW / DIS1|≤1.875, 14.167≤|FT / DIS2|≤113.535.

[0141] Among them, by reasonably limiting the ratio between the focal length of the zoom lens at the wide-angle end and the telephoto end and the corresponding distortion, it is possible to ensure that while achieving a high magnification ratio and a large target area, the distortion is controlled within a reasonable range, thereby better magnifying the details of the required imaging picture and maintaining a good imaging effect.

[0142] Specific embodiments of the zoom lens applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0143] Example 1

[0144] like Figure 1 and Figure 2 As shown, the zoom lens provided by the first embodiment of the present invention includes a first fixed lens group G1, a first magnification lens group G2, a second magnification lens group G3, a focus lens group G4 and a second fixed lens group G5 arranged in sequence along the optical axis from the object plane to the image plane.

[0145] The first fixed lens group G1 includes the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, arranged in sequence from the object plane to the image plane. The first variator group G2 includes the fifth lens L5, the sixth lens L6, and the seventh lens L7, arranged in sequence from the object plane to the image plane. The second variator group G3 includes the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, and the twelfth lens L12, arranged in sequence from the object plane to the image plane. The focusing lens group G4 includes the thirteenth lens L13 and the fourteenth lens L14, arranged in sequence from the object plane to the image plane. The second fixed lens group G5 includes the fifteenth lens L15 and the sixteenth lens L16, arranged in sequence from the object plane to the image plane.

[0146] The aperture STO is located in the optical path between the seventh lens L7 and the eighth lens L8, and the filter P is located on the image-side surface of the sixteenth lens L16.

[0147] Table 1 details the specific optical and physical parameters of each lens in the zoom lens provided in Example 1 of the present invention in a feasible implementation manner. The zoom lens in Table 1 corresponds to Figure 1 and Figure 2 Zoom lens shown.

[0148] Table 1 Design values ​​of optical physical parameters of zoom lens

[0149]

[0150]

[0151] The surface numbers in Table 1 are numbered according to the order of the surfaces of each lens, where "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature of the lens surface, a positive value represents that the surface is curved toward the image side, and a negative value represents that the surface is curved toward the object side, "INF" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the refractive index (Nd) represents the light deflection ability of the material between the current surface and the next surface, and a blank space represents that the current position is air with a refractive index of 1; the Abbe number (Vd) represents the dispersion characteristics of the material between the current surface and the next surface, and a blank space represents that the current position is air; the half-aperture represents the half-height of the light on the surface of each lens.

[0152] Table 2 shows the values ​​of the zoom intervals of the zoom lens in Table 1 at the wide-angle end and the telephoto end.

[0153] Table 2 Design values ​​of zoom intervals of zoom lenses

[0154] Wide-angle end Telephoto end Zoom interval 1 -25.567 -0.793 Zoom interval 2 25.567 0.793 Zoom interval 3 5.400 -0.389 Zoom interval 4 -5.400 0.389 Zoom interval 5 -5.068 -1.429 Zoom interval 6 5.068 1.429

[0155] wherein the zoom interval in Table 2 is the interval value of the zoom lens at the wide-angle end and the telephoto end.

[0156] In the present embodiment, the aspheric conic coefficients of the aspheric lenses in the zoom lens can be defined by the following aspheric formula, but are not limited to the following representation:

[0157]

[0158] wherein z is the axial height of the aspheric Z direction; r is the height of the aspheric; c is the curvature of the fitting sphere, which is the reciprocal of the radius of curvature in value; k is the fitting conic coefficient; A-G are the 4th order, 6th order, 8th order, 10th order, 12th order, 14th order and 16th order term coefficients of the aspheric polynomial.

[0159] For example, Table 3 details the aspheric conic coefficients of each lens in Embodiment I in a possible implementation.

[0160] Table 3: Design values of the aspheric conic coefficients of each lens in the zoom lens

[0161]

[0162] The K value in Table 3 represents the numerical value of the best fitting conic coefficient of the aspheric.

[0163] The zoom lens of Embodiment I can achieve the following technical indexes:

[0164] Table 4: Technical indexes of the zoom lens

[0165]

[0166] Figure 7 The field curvature distortion chart of the zoom lens provided by Embodiment I at the wide-angle end, Figure 8 The field curvature distortion chart of the zoom lens provided by Embodiment I at the telephoto end. In the left coordinate system in the figure, the horizontal coordinate represents the size of the field curvature, with the unit of mm; the vertical coordinate represents the normalized image height without unit. In the right coordinate system in the figure, the horizontal coordinate represents the size of the distortion (F-Tan(Theta)), with the unit of %; the vertical coordinate represents the normalized image height without unit. From the figure, it can be seen that Figure 7 and Figure 8 It can be seen that the field curvature of the zoom lens provided by the present embodiment at the wide-angle end and the telephoto end is effectively controlled, i.e. the difference between the central image quality and the peripheral image quality is small during imaging. At the same time, the distortion of the zoom lens at the wide-angle end and the telephoto end is within ±10%, so the distortion of the zoom lens provided by the present embodiment at the wide-angle end and the telephoto end is well corrected, and the imaging distortion is small.

[0167] Figure 9 The ray fan diagram of the zoom lens provided by the embodiment one of the present application at the wide-angle end, Figure 10 The ray fan diagram of the zoom lens provided by the embodiment one of the present application at the long-focus end, wherein the ray fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal coordinate in the diagram is the beam aperture, and the vertical coordinate is the sagittal aberration. The most ideal curve is a straight line coinciding with the horizontal coordinate, indicating that all rays converge to the same point on the image plane. The corresponding interval on the vertical coordinate of the curve is the maximum dispersion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the sagittal chromatic aberration. From Figure 9 and Figure 10 It can be seen that the zoom lens is close to the horizontal coordinate at each field of view and each wavelength, indicating that the sagittal aberration of each wavelength is well corrected. At the same time, the curves of each wavelength are not obviously dispersed, indicating that the chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is also well corrected, thereby ensuring that the zoom lens can meet the high-resolution imaging requirements.

[0168] Figure 11 The sagittal chromatic aberration diagram of the zoom lens provided by the embodiment one of the present application at the wide-angle end, Figure 12 The sagittal chromatic aberration diagram of the zoom lens provided by the embodiment one of the present application at the long-focus end, wherein the vertical direction represents the normalization of the field of view, and 0 represents on the optical axis; the main wavelength uses 546nm, and the horizontal direction represents the offset amount relative to the main wavelength, with the unit of micrometers (μm), Figure 11 and Figure 12 The maximum field of view in the diagram is 4.6mm. From Figure 11 and Figure 12 It can be seen that the sagittal chromatic aberration of different wavelengths is controlled within a good range, indicating that the sagittal chromatic aberration of the zoom lens at the wide-angle end and the long-focus end is well controlled, and can meet the wide-spectrum application requirements.

[0169] Embodiment two

[0170] As shown in Figure 3 and Figure 4 The zoom lens provided by the embodiment two of the present application comprises, in order along the optical axis from the object plane to the image plane, a first fixed lens group G1, a first variable magnification lens group G2, a second variable magnification lens group G3, a focusing lens group G4, and a second fixed lens group G5.

[0171] The first fixed lens group G1 includes the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, arranged in sequence from the object plane to the image plane. The first variator group G2 includes the fifth lens L5, the sixth lens L6, and the seventh lens L7, arranged in sequence from the object plane to the image plane. The second variator group G3 includes the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, and the twelfth lens L12, arranged in sequence from the object plane to the image plane. The focusing lens group G4 includes the thirteenth lens L13 and the fourteenth lens L14, arranged in sequence from the object plane to the image plane. The second fixed lens group G5 includes the fifteenth lens L15 and the sixteenth lens L16, arranged in sequence from the object plane to the image plane.

[0172] The aperture STO is located in the optical path between the seventh lens L7 and the eighth lens L8, and the filter P is located on the image-side surface of the sixteenth lens L16.

[0173] Table 5 details the specific optical and physical parameters of each lens in the zoom lens provided in Example 2 of the present invention in a feasible implementation manner. The zoom lens in Table 5 corresponds to Figure 3 and Figure 4 Zoom lens shown.

[0174] Table 5 Design values ​​of optical physical parameters of zoom lens

[0175]

[0176]

[0177] The surface numbers in Table 5 are numbered according to the order of the surfaces of each lens, where "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature of the lens surface, a positive value represents that the surface is curved toward the image side, and a negative value represents that the surface is curved toward the object side, "INF" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the refractive index (Nd) represents the light deflection ability of the material between the current surface and the next surface, and a blank space represents that the current position is air with a refractive index of 1; the Abbe number (Vd) represents the dispersion characteristics of the material between the current surface and the next surface, and a blank space represents that the current position is air; the half-aperture represents the half-height of the light on the surface of each lens.

[0178] Table 6 shows the values ​​of the zoom intervals of the zoom lens in Table 5 at the wide-angle end and the telephoto end.

[0179] Table 6 Design values ​​of zoom intervals of zoom lenses

[0180] Wide-angle end Telephoto end Zoom interval 1 -25.941 -0.739 Zoom interval 2 25.941 0.739 Zoom interval 3 5.806 -0.708 Zoom interval 4 -5.806 0.708 Zoom interval 5 -4.985 -1.321 Zoom interval 6 4.985 1.321

[0181] The zoom intervals in Table 6 are the different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0182] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0183]

[0184] Among them, z is the axial sagittal height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted sphere, which is the inverse of the curvature radius; k is the fitting cone coefficient; AG is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspheric polynomial.

[0185] For example, Table 7 describes in detail the aspheric conic coefficients of each lens in the second embodiment in a feasible implementation manner.

[0186] Table 7 Design values ​​of aspheric cone coefficients of each lens in the zoom lens

[0187]

[0188] The K value in Table 7 represents the numerical value of the best-fit cone coefficient of the aspheric surface.

[0189] The zoom lens of the second embodiment can achieve the following technical indicators:

[0190] Table 8 Technical specifications of zoom lenses

[0191]

[0192] Figure 13 This is a diagram of field curvature distortion of the zoom lens provided in Example 2 of the present invention at the wide-angle end. Figure 14 This is a diagram of the field curvature distortion of the zoom lens provided in Example 2 of the present invention at the telephoto end. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, without a unit. In the coordinate system on the right side of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in %, and the vertical coordinate represents the normalized image height, without a unit. Figure 13 and Figure 14 It can be seen that the zoom lens provided by this embodiment effectively controls field curvature at both the wide-angle and telephoto ends. This means that the image quality difference between the center and periphery is minimal. Furthermore, the distortion of the zoom lens at both the wide-angle and telephoto ends is within the ±10% range. Therefore, the zoom lens provided by this embodiment effectively corrects distortion at both the wide-angle and telephoto ends, resulting in minimal imaging distortion.

[0193] Figure 15 This is a ray fan diagram of the zoom lens at the wide-angle end provided by the second embodiment of the present invention. Figure 16 The light fan diagram of the zoom lens at the telephoto end provided in the second embodiment of the present invention, wherein the light fan diagram is one of the most commonly used evaluation methods in modern optical design. In the diagram, the horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum diffusion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. By Figure 15 and Figure 16 It can be seen that the zoom lens is well aligned with the horizontal axis at all wavelengths in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion in the curves for each wavelength, indicating that the chromatic aberration of the zoom lens at the wide-angle and telephoto ends is also well corrected, thus ensuring that the zoom lens can meet high-resolution imaging requirements.

[0194] Figure 17 This is a diagram of vertical axis chromatic aberration of the zoom lens provided in Example 2 of the present invention at the wide-angle end. Figure 18 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 2 of the present invention at the telephoto end. The vertical direction represents the normalized field of view, with 0 indicating the optical axis. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength in micrometers (μm). Figure 17 and Figure 18 The maximum field of view is 4.5 mm. Figure 17 and Figure 18 It can be seen that the vertical chromatic aberration of different wavelengths is well controlled, indicating that the vertical chromatic aberration of this zoom lens at both the wide-angle and telephoto ends is well controlled, which can meet the needs of wide-spectrum applications.

[0195] Example 3

[0196] like Figure 5 and Figure 6 As shown, the zoom lens provided by the third embodiment of the present invention includes a first fixed lens group G1, a first magnification lens group G2, a second magnification lens group G3, a focus lens group G4 and a second fixed lens group G5 arranged in sequence along the optical axis from the object plane to the image plane.

[0197] The first fixed lens group G1 includes the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, arranged in sequence from the object plane to the image plane. The first variator group G2 includes the fifth lens L5, the sixth lens L6, and the seventh lens L7, arranged in sequence from the object plane to the image plane. The second variator group G3 includes the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, and the twelfth lens L12, arranged in sequence from the object plane to the image plane. The focusing lens group G4 includes the thirteenth lens L13 and the fourteenth lens L14, arranged in sequence from the object plane to the image plane. The second fixed lens group G5 includes the fifteenth lens L15 and the sixteenth lens L16, arranged in sequence from the object plane to the image plane.

[0198] The aperture STO is located in the optical path between the seventh lens L7 and the eighth lens L8, and the filter P is located on the image-side surface of the sixteenth lens L16.

[0199] Table 9 details the specific optical and physical parameters of each lens in the zoom lens provided in Example 3 of the present invention in a feasible implementation manner. The zoom lens in Table 9 corresponds to Figure 5 and Figure 6 Zoom lens shown.

[0200] Table 9 Design values ​​of optical physical parameters of zoom lens

[0201]

[0202]

[0203] The surface numbers in Table 9 are numbered according to the order of the surfaces of each lens, where "1" represents the object side surface of the first lens, "2" represents the image side surface of the first lens, and so on; "STO" represents the aperture of the zoom lens; the radius of curvature represents the degree of curvature of the lens surface, a positive value represents that the surface is curved toward the image side, and a negative value represents that the surface is curved toward the object side, "INF" indicates that the surface is flat and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the refractive index (Nd) represents the light deflection ability of the material between the current surface and the next surface, and a blank space represents that the current position is air with a refractive index of 1; the Abbe number (Vd) represents the dispersion characteristics of the material between the current surface and the next surface, and a blank space represents that the current position is air; the half-aperture represents the half-height of the light on the surface of each lens.

[0204] Table 10 shows the values ​​of the zoom intervals of the zoom lens in Table 9 at the wide-angle end and the telephoto end.

[0205] Table 10 Design values ​​of zoom intervals of zoom lenses

[0206]

[0207]

[0208] The zoom intervals in Table 10 are the different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0209] In this embodiment, the aspheric cone coefficient of the aspheric lens in the zoom lens can be defined by the following aspheric formula, but is not limited to the following expression method:

[0210]

[0211] Among them, z is the axial sagittal height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted sphere, which is the inverse of the curvature radius; k is the fitting cone coefficient; AG is the coefficient of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspheric polynomial.

[0212] For example, Table 11 describes in detail the aspheric conic coefficients of each lens in Example 3 in a feasible implementation manner.

[0213] Table 11 Design values ​​of aspheric cone coefficients of each lens in the zoom lens

[0214]

[0215] The K value in Table 11 represents the numerical value of the best-fit cone coefficient of the aspheric surface.

[0216] The zoom lens of the third embodiment can achieve the following technical indicators:

[0217] Table 12 Technical specifications of zoom lenses

[0218]

[0219]

[0220] Figure 19 This is a field curvature distortion diagram of the zoom lens provided in Example 3 of the present invention at the wide-angle end. Figure 20 This is a diagram of the field curvature distortion of the zoom lens provided in Example 3 of the present invention at the telephoto end. In the coordinate system on the left side of the figure, the horizontal coordinate represents the magnitude of the field curvature, in mm; the vertical coordinate represents the normalized image height, without a unit. In the coordinate system on the right side of the figure, the horizontal coordinate represents the magnitude of the distortion (F-Tan(Theta)), in %, and the vertical coordinate represents the normalized image height, without a unit. Figure 19 and Figure 20It can be seen that the zoom lens provided by this embodiment effectively controls field curvature at both the wide-angle and telephoto ends. This means that the image quality difference between the center and periphery is minimal. Furthermore, the distortion of the zoom lens at both the wide-angle and telephoto ends is within the ±10% range. Therefore, the zoom lens provided by this embodiment effectively corrects distortion at both the wide-angle and telephoto ends, resulting in minimal imaging distortion.

[0221] Figure 21 This is a ray fan diagram of the zoom lens provided in the third embodiment of the present invention at the wide-angle end. Figure 22 The light fan diagram of the zoom lens at the telephoto end provided in the third embodiment of the present invention, wherein the light fan diagram is one of the most commonly used evaluation methods in modern optical design. In the diagram, the horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum diffusion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. By Figure 21 and Figure 22 It can be seen that the zoom lens is well aligned with the horizontal axis at all wavelengths in all fields of view, indicating that the vertical aberration of each wavelength is well corrected. At the same time, there is no obvious dispersion in the curves for each wavelength, indicating that the chromatic aberration of the zoom lens at the wide-angle and telephoto ends is also well corrected, thus ensuring that the zoom lens can meet high-resolution imaging requirements.

[0222] Figure 23 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 3 of the present invention at the wide-angle end. Figure 24 This is a diagram of vertical axial chromatic aberration of the zoom lens provided in Example 3 of the present invention at the telephoto end. The vertical direction represents the normalized field of view, with 0 indicating the optical axis. The dominant wavelength is 546 nm, and the horizontal direction represents the offset relative to the dominant wavelength in micrometers (μm). Figure 23 and Figure 24 The maximum field of view is 4.6 mm. Figure 23 and Figure 24 It can be seen that the vertical chromatic aberration of different wavelengths is well controlled, indicating that the vertical chromatic aberration of this zoom lens at both the wide-angle and telephoto ends is well controlled, which can meet the needs of wide-spectrum applications.

[0223] In order to more clearly illustrate the above embodiments, Table 13 details the specific optical and physical parameters of each lens in the zoom lens provided in Embodiments 1 to 3 of the present invention.

[0224] Table 13 Design values ​​of optical physical parameters of zoom lens

[0225] Example 1 Example 2 Example 3 FG1 / FW 6.569 6.999 5.846 FG2 / FW -1.314 -1.356 -1.165 FG3 / FW 3.448 3.644 3.086 FG4 / FW 4.222 4.586 3.815 FG5 / FW -21.129 -27.451 -11.710 |F1 / F101| 0.437 0.432 0.437 |F101 / (FT / FW)| 18.710 16.890 19.155 Nd1 1.55 1.56 1.55 Vd1 96.00 75.00 84.38 Nd2 1.50 1.49 1.50 Vd2 77.23 60.00 85.01 Nd3 1.83 1.80 1.86 Vd3 42.93 60.00 38.10 TTL / FW 14.554 15.805 13.156 TTL / FT 0.930 0.903 0.861 D2 / TTL 0.266 0.266 0.261 D3 / TTL 0.062 0.069 0.056 D4 / TTL 0.039 0.039 0.041 |FG2 / F5| 0.822 0.806 0.822 |FG2 / F6| 0.427 0.420 0.428 |FG2 / F7| 0.288 0.271 0.288 |FG3 / F8| 0.710 0.707 0.715 |FG3 / F9| 0.337 0.335 0.338 |FG3 / F10| 0.758 0.756 0.762 |FG3 / F11| 1.897 1.884 1.917 |FG3 / F12| 0.848 0.843 0.853 FT / FW 15.645 17.500 15.278 |FW / DIS1| 1.368 0.862 1.252 |FT / DIS1| 28.401 32.308 70.968

[0226] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A zoom lens, characterized in that: The lens comprises a first fixed lens group, a first magnification lens group, a second magnification lens group, a focus lens group and a second fixed lens group, which are arranged in sequence along the optical axis from the object plane to the image plane; The first fixed lens group and the second fixed lens group are fixedly arranged, and the first magnification changer group, the second magnification changer group and the focus lens group are movable along the optical axis direction; The first fixed lens group has positive optical power, the first variator group has negative optical power, the second variator group has positive optical power, the focus lens group has positive optical power, and the second fixed lens group has negative optical power; The first fixed lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object plane to the image plane; the first lens has negative optical power, the second lens has positive optical power, the third lens has positive optical power, and the fourth lens has positive optical power; The first zoom lens group includes a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object plane to the image plane; the fifth lens has negative optical power, the sixth lens has negative optical power, and the seventh lens has positive optical power; The second zoom lens group includes an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object plane to the image plane; the eighth lens has positive refractive power, the ninth lens has positive refractive power, the tenth lens has positive refractive power, the eleventh lens has negative refractive power, and the twelfth lens has positive refractive power; The focusing lens group includes a thirteenth lens and a fourteenth lens arranged in sequence from the object plane to the image plane; the thirteenth lens has positive refractive power, and the fourteenth lens has negative refractive power; The second fixed lens group includes a fifteenth lens and a sixteenth lens arranged in sequence from the object plane to the image plane; the fifteenth lens has positive refractive power, and the sixteenth lens has negative refractive power; The number of lenses with optical power in the zoom lens is 16; The focal length of the first fixed lens group is FG1, the focal length of the first variator group is FG2, the focal length of the second variator group is FG3, the focal length of the focus lens group is FG4, the focal length of the second fixed lens group is FG5, and the focal length of the zoom lens at the wide-angle end is FW, wherein: 4.694≤FG1 / FW≤8.151; -1.547≤FG2 / FW≤-0.974; 2.529≤FG3 / FW≤4.201; 3.044≤FG4 / FW≤5.357; -27.451≤FG5 / FW≤-11.710; The total optical length of the zoom lens is TTL, and the focal length of the zoom lens at the telephoto end is FT; Among them, 10.506≤TTL / FW≤18.454, 0.792≤TTL / FT≤0.

999.

2. The zoom lens according to claim 1, wherein: The first lens and the second lens form a first cemented lens group; The tenth lens and the eleventh lens form a second cemented lens group; The thirteenth lens and the fourteenth lens form a third cemented lens group.

3. The zoom lens according to claim 1, wherein: The first lens and the second lens form a first cemented lens group; The focal length of the first lens is F1, and the focal length of the first cemented lens group is F101, wherein 0.428≤|F1 / F101|≤0.

628.

4. The zoom lens according to claim 1, wherein: The first lens and the second lens form a first cemented lens group; The focal length of the first cemented lens group is F101; Among them, 14.625≤|F101 / (FT / FW)|≤21.

419.

5. The zoom lens according to claim 1, wherein: The sixth lens, the twelfth lens and the sixteenth lens are all glass aspherical lenses; The refractive index of the sixth lens is Nd1, and the Abbe number is Vd1; the refractive index of the twelfth lens is Nd2, and the Abbe number is Vd2; the refractive index of the sixteenth lens is Nd3, and the Abbe number is Vd3; wherein: 1.45≤Nd1≤1.56;54.00≤Vd1≤96.00; 1.45≤Nd2≤1.55;34.00≤Vd2≤95.00; 1.78≤Nd3≤1.86;20.00≤Vd3≤95.

00.

6. The zoom lens according to claim 1, wherein: The maximum movable distance of the first zoom lens group is D2, the maximum movable distance of the second zoom lens group is D3, and the maximum movable distance of the focus lens group is D4; wherein, 0.256≤D2 / TTL≤0.272, 0.042≤D3 / TTL≤0.082, and 0.037≤D4 / TTL≤0.

056.

7. The zoom lens according to claim 1, wherein: 13.055≤FT / FW≤19.723.

Images