Zoom lens and monitoring device

Abstract

The utility model discloses a zoom lens and a monitoring device, and relates to the technical field of optical systems, the zoom lens is provided with an object side and an image side which are oppositely arranged along the optical axis direction, and the zoom lens comprises a first lens group to a seventh lens group which are sequentially arranged from the object side to the image side; the first lens group, the third lens group, the fifth lens group and the seventh lens group have positive focal power, and the second lens group, the fourth lens group and the sixth lens group have negative focal power; wherein the second lens group, the fourth lens group and the fifth lens group are movably arranged along the extension direction of the optical axis for zooming, and the sixth lens group is movably arranged along the direction of the optical axis for focusing; therefore, the focal length of the zoom lens can be adjusted in a range larger than or equal to 4.4 mm and smaller than or equal to 169.4 mm, and the aperture number of the zoom lens can be adjusted in a range larger than or equal to 1.68 and smaller than or equal to 4.95. According to the utility model, the multiple movable lens groups are arranged to adjust the multiplying power and the definition of the zoom lens.

Description

Technical Field

[0001] The utility model relates to the technical field of optical systems, in particular to a zoom lens and monitoring equipment. Background Art

[0002] In the security field, zoom lenses have been widely used due to their advantages such as long shooting distance and large shooting angle. With the development of technology, the application of 4K cameras has gradually become popular in the security field. High pixels, large magnification, small size, large angle and small distortion have become requirements for the new generation of security zoom lenses.

[0003] The mainstream high-quality surveillance system zoom lenses on the market currently have problems such as low clarity, small magnification, large size, and large distortion. In addition, the target size of the mainstream photosensitive chip on the market is 1 / 2.8″, and the resolution is mostly 4M, 20 times to 30 times, which is increasingly unable to meet market demand. The demand for high-magnification ultra-high-definition 4K resolution is getting higher and higher, but there are few types of large-magnification and 4K high-definition lenses on the market that can match the 1 / 2.8″ photosensitive chip and cannot meet market demand. Utility Model Content

[0004] The main purpose of the utility model is to provide a zoom lens and a monitoring device, and in particular to provide a zoom lens with high pixel and large magnification.

[0005] To achieve the above-mentioned purpose, the utility model provides a zoom lens, the zoom lens has an object side and an image side which are arranged opposite to each other along the optical axis direction, the zoom lens comprises a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a sixth lens group and a seventh lens group which are arranged in sequence from the object side to the image side; the first lens group, the third lens group, the fifth lens group and the seventh lens group have positive focal power, and the second lens group, the fourth lens group and the sixth lens group have negative focal power; wherein the second lens group, the fourth lens group and the fifth lens group are movably arranged along the extension direction of the optical axis for zooming, and the sixth lens group is movably arranged along the optical axis direction for focusing; so that the focal length of the zoom lens is adjustable within a range of greater than or equal to 4.4 mm and less than or equal to 169.4 mm, and the aperture number of the zoom lens is adjustable within a range of greater than or equal to 1.68 and less than or equal to 4.95.

[0006] In one embodiment, the zoom lens is in a wide-angle state, with a focal length F, F=4.4 mm;

[0007] The focal length of the first lens group is f1, 0.048≤F / f1≤0.066;

[0008] The focal length of the second lens group is f2, -0.738≤F / f2≤-0.546;

[0009] The focal length of the third lens group is f3, 0.340≤F / f3≤0.460;

[0010] The focal length of the fourth lens group is f4, -0.500≤F / f4≤-0.369;

[0011] The focal length of the fifth lens group is f5, 0.286≤F / f5≤0.387;

[0012] The focal length of the sixth lens group is f6, -0.421≤F / f6≤-0.311;

[0013] The focal length of the seventh lens group is f7, 0.207≤F / f7≤0.280.

[0014] In one embodiment, the first lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side, the focal length of the first lens is f11, -1.283≤f1 / f11≤-0.948; the focal length of the second lens is f12, 0.858≤f1 / f12≤1.160; the focal length of the third lens is f13, 0.718≤f1 / f13≤0.971; the focal length of the fourth lens is f14, 0.884≤f1 / f14≤1.197;

[0015] The second lens group includes a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side, the focal length of the fifth lens is f21, 0.533≤f2 / f21≤0.722; the focal length of the sixth lens is f22, 0.516≤f2 / f22≤0.698; the focal length of the seventh lens is f23, -0.381≤f2 / f23≤-0.282;

[0016] The third lens group includes an eighth lens, the focal length of the eighth lens is f31, 0.833≤f3 / f31≤1.250;

[0017] The fourth lens group includes a ninth lens, the focal length of the ninth lens is f41, 0.833≤f4 / f41≤1.250;

[0018] The fifth lens group includes a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object side to the image side, the focal length of the tenth lens is f51, 0.871≤f5 / f51≤1.179; the focal length of the eleventh lens is f52, -1.289≤f5 / f52≤-0.952; the focal length of the twelfth lens is f53, 0.934≤f5 / f53≤1.263;

[0019] The sixth lens group includes a thirteenth lens, the focal length of the thirteenth lens is f61, 0.833≤f6 / f61≤1.250;

[0020] The seventh lens group includes a fourteenth lens, and the focal length of the fourteenth lens is f71, 0.833≤f7 / f71≤1.250.

[0021] In one embodiment, the first lens, the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, the eleventh lens, and the twelfth lens are all configured as spherical lenses;

[0022] The fifth lens, the eighth lens, the ninth lens, the tenth lens, the thirteenth lens, and the fourteenth lens are all configured as aspherical lenses.

[0023] In one implementation, the first lens is cemented to the second lens, the sixth lens is cemented to the seventh lens, and the eleventh lens is cemented to the twelfth lens.

[0024] In one embodiment, the Abbe number of the first lens is V1, 32.00≤V1≤32.64;

[0025] The Abbe number of the second lens is V2, 93.57≤V2≤95.47;

[0026] The Abbe number of the third lens is V3, 80.79≤V3≤82.43;

[0027] The Abbe number of the fourth lens is V4, 67.66≤V4≤69.02;

[0028] The Abbe number of the fifth lens is V5, 49.02≤V5≤50.02;

[0029] The Abbe number of the sixth lens is V6, 51.80≤V6≤52.84;

[0030] The Abbe number of the seventh lens is V7, 17.76≤V7≤18.12;

[0031] The Abbe number of the eighth lens is V8, 70.96≤V8≤72.40;

[0032] The Abbe number of the ninth lens is V9, 66.35≤V9≤67.69;

[0033] The Abbe number of the tenth lens is V10, 80.74≤V10≤82.38;

[0034] The Abbe number of the eleventh lens is V11, 42.30≤V11≤43.16;

[0035] The Abbe number of the twelfth lens is V12, 94.15≤V12≤96.05;

[0036] The Abbe number of the thirteenth lens is V13, 49.01≤V13≤50.00;

[0037] The Abbe number of the fourteenth lens is V14, 80.74≤V14≤82.38.

[0038] In one embodiment, the refractive index of the first lens is N1, 1.9481≤N1≤1.9520;

[0039] The refractive index of the second lens is N2, 1.4386≤N2≤1.4414;

[0040] The refractive index of the third lens is N3, 1.4985≤N3≤1.5015;

[0041] The refractive index of the fourth lens is N4, 1.5884≤N4≤1.5916;

[0042] The refractive index of the fifth lens is N5, 1.7682≤N5≤1.7718;

[0043] The refractive index of the sixth lens is N6, 1.7483≤N6≤1.7518;

[0044] The refractive index of the seventh lens is N7, 1.9481≤N7≤1.9520;

[0045] The refractive index of the eighth lens is N8, 1.5485≤N8≤1.5516;

[0046] The refractive index of the ninth lens is N9, 1.5884≤N9≤1.5916;

[0047] The refractive index of the tenth lens is N10, 1.4985≤N10≤1.5015;

[0048] The refractive index of the eleventh lens is N11, 1.8282≤N11≤1.8318;

[0049] The refractive index of the twelfth lens is N12, 1.4386≤N12≤1.4414;

[0050] The refractive index of the thirteenth lens is N13, 1.7682≤N13≤1.7718;

[0051] The refractive index of the fourteenth lens is N14, 1.4985≤N14≤1.5015.

[0052] In one embodiment, the total optical length of the zoom lens is TTL, TTL≤96mm;

[0053] The movable stroke of the second lens group in the optical axis direction is A1, A1≥28.1mm and 0.255≤A1 / TTL≤0.331;

[0054] The movable stroke of the fourth lens group in the optical axis direction is A2, A2≥4.7mm and 0.042≤A2 / TTL≤0.055;

[0055] The movable stroke of the fifth lens group in the optical axis direction is A3, A3≥8.3mm and 0.075≤A3 / TTL≤0.098;

[0056] The movable stroke of the sixth lens group in the optical axis direction is A4, A4≥12.1mm and 0.109≤A4 / TTL≤0.142.

[0057] In one embodiment, the zoom lens further includes:

[0058] an aperture, the aperture being disposed between the second lens group and the third lens group; and

[0059] An imaging plane, located on the image side of the seventh lens group;

[0060] Wherein, the distance from the aperture to the imaging surface is L, and 0.448≤L / TTL≤0.538.

[0061] The utility model also proposes a monitoring device, which includes a zoom lens, wherein the zoom lens has an object side and an image side which are relatively arranged along the optical axis direction, and the zoom lens includes a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a sixth lens group, and a seventh lens group which are arranged in sequence from the object side to the image side; the first lens group, the third lens group, the fifth lens group, and the seventh lens group have positive optical focal length, and the second lens group, the fourth lens group, and the sixth lens group have negative optical focal length; wherein the second lens group, the fourth lens group, and the fifth lens group are movably arranged along the extension direction of the optical axis for zooming, and the sixth lens group is movably arranged along the optical axis direction for focusing; so that the focal length of the zoom lens is adjustable within a range of greater than or equal to 4.4 mm and less than or equal to 169.4 mm, and the aperture number of the zoom lens is adjustable within a range of greater than or equal to 1.68 and less than or equal to 4.95.

[0062] The technical solution of the utility model is to adjust the magnification and clarity of the zoom lens by arranging a plurality of movable lens groups. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0064] Figure 1 A schematic structural diagram of an embodiment of a zoom lens provided by the utility model in a wide-angle state;

[0065] Figure 2 A schematic structural diagram of an embodiment of a zoom lens provided by the utility model in a telephoto state;

[0066] Figure 3 for Figure 1 Through-focus MTF graph of a medium zoom lens at 140lp / mm at wide angle;

[0067] Figure 4 for Figure 1 MTF-Field diagram of a medium zoom lens at wide angle;

[0068] Figure 5 for Figure 1 The through-focus MTF graph of a medium zoom lens at 180lp / mm at wide angle;

[0069] Figure 6 for Figure 1 Field curvature-distortion diagram of a medium zoom lens at wide angle;

[0070] Figure 7 for Figure 1 Light fan diagram of a medium zoom lens at wide angle;

[0071] Figure 8 for Figure 1 Axial aberration diagram of a medium zoom lens at wide angle;

[0072] Fig. 9 for Figure 1 Vertical axis chromatic aberration diagram of the medium zoom lens at wide angle;

[0073] Fig.10 for Figure 2 The through-focus MTF graph of a medium zoom lens at 140lp / mm at telephoto.

[0074] Fig.11 for Figure 2 MTF-Field diagram of a medium zoom lens in telephoto state;

[0075] Fig.12 for Figure 2 The through-focus MTF diagram of a medium zoom lens at 180lp / mm in telephoto mode.

[0076] Fig.13 for Figure 2 Field curvature-distortion diagram of a medium zoom lens at telephoto position;

[0077] Fig.14 for Figure 2 Light fan diagram of a medium zoom lens in telephoto mode;

[0078] Fig.15 for Figure 2 Axial aberration diagram of a medium zoom lens at telephoto position;

[0079] Fig.16 for Figure 2 Vertical axis chromatic aberration diagram of a medium zoom lens in telephoto position.

[0080] Description of Figure Numbers:

[0081] 100. zoom lens; 1. first lens group; 11. first lens; 12. second lens; 13. third lens; 14. fourth lens; 2. second lens group; 21. fifth lens; 22. sixth lens; 23. seventh lens; 3. third lens group; 31. eighth lens; 4. fourth lens group; 41. ninth lens; 5. fifth lens group; 51. tenth lens; 52. eleventh lens; 53. twelfth lens; 6. sixth lens group; 61. thirteenth lens; 7. seventh lens group; 71. fourteenth lens; 8. aperture; 9. imaging surface; 10. filter.

[0082] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0083] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0084] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0085] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0086] The mainstream high-quality surveillance system zoom lenses on the market currently have problems such as low clarity, small magnification, large size, and large distortion. In addition, the target size of the mainstream photosensitive chip on the market is 1 / 2.8″, and the resolution is mostly 4M, 20 times to 30 times, which is increasingly unable to meet market demand. The demand for high-magnification ultra-high-definition 4K resolution is getting higher and higher, but there are few types of large-magnification and 4K high-definition lenses on the market that can match the 1 / 2.8″ photosensitive chip and cannot meet market demand.

[0087] The utility model provides a zoom lens.

[0088] See also Figure 1 In one embodiment of the utility model, the zoom lens 100 has an object side and an image side which are arranged opposite to each other along the optical axis direction, and the zoom lens 100 includes a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4, a fifth lens group 5, a sixth lens group 6, and a seventh lens group 7 which are arranged in sequence from the object side to the image side; the first lens group 1, the third lens group 3, the fifth lens group 5, and the seventh lens group 7 have positive focal power, and the second lens group 2, the fourth lens group 4, and the sixth lens group 6 have negative focal power; wherein the second lens group 2, the fourth lens group 4, and the fifth lens group 5 are movably arranged along the extension direction of the optical axis for zooming, and the sixth lens group 6 is movably arranged along the optical axis direction for focusing; so that the focal length of the zoom lens 100 is adjustable within a range of greater than or equal to 4.4 mm and less than or equal to 169.4 mm, and the aperture number of the zoom lens 100 is adjustable within a range of greater than or equal to 1.68 and less than or equal to 4.95.

[0089] The magnification of the zoom lens 100, that is, the degree of magnification or reduction of the image, is related to the focal length of the zoom lens 100. The shorter the focal length, the stronger the focusing ability of the zoom lens 100 on light, and the greater the magnification of the image. The magnification of the image is adjusted by changing the relative positions of the lens groups in the zoom lens 100. For example, in the zoom lens 100, by changing the position of the moving lens group, the continuous change of the focal length can be achieved, thereby achieving a zoom effect. Therefore, the technical solution of the utility model is through the object side and the image side that are relatively arranged along the optical axis direction. The zoom lens 100 includes a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4, a fifth lens group 5, a sixth lens group 6, and a seventh lens group 7 arranged in sequence from the object side to the image side, wherein the second lens group 2, the fourth lens group 4 and the fifth lens group 5 are movably arranged along the extension direction of the optical axis to achieve the zoom of the zoom lens 100. The clarity of the zoom lens 100 is affected by many factors, including the quality of the lens groups, the relative positions between the lens groups, and the overall design of the zoom lens 100. The focusing system of the zoom lens 100 can make the image clear by moving the lens groups so that the image is presented on the imaging surface 9. In order to achieve this function, the sixth lens group 6 is movably arranged along the optical axis direction to achieve the focusing of the zoom lens 100. In the zoom lens 100, the movement of the lens group is the key to achieving focal length change. When the focal length of the zoom lens 100 becomes shorter, the range of the captured picture becomes wider; and when the focal length of the zoom lens 100 becomes longer, the range of the captured picture becomes narrower, but the details are clearer. Therefore, the zoom lens 100 has two extreme states, namely the wide-angle state (such as Figure 1 As shown), telephoto state (as shown Figure 2 As shown). As well as the intermediate state adjusted between these two states, the position of the corresponding lens group can be adjusted according to the on-site requirements. In the zoom lens 100, the optical focal length of multiple lens groups is set to negative or positive in order to achieve specific optical effects and correct aberrations. In the design of the zoom lens 100, the optical focal length of the lens group is alternately set to negative and positive to achieve better optical performance, ensuring that the light can enter the subsequent structure through the focusing lens group at a larger angle, ensuring the wide-angle characteristics of the zoom lens 100. Therefore, the first lens group 1, the third lens group 3, the fifth lens group 5, and the seventh lens group 7 are set to lens groups with positive optical focal length; the second lens group 2, the fourth lens group 4, and the sixth lens group 6 are set to lens groups with negative optical focal length.

[0090] For specific implementation, the focal length of the zoom lens 100 is adjustable within a range of greater than or equal to 4.4 mm and less than or equal to 169.4 mm. For an optical lens, different maximum aperture values ​​are provided at different focal lengths, and the range of aperture values ​​will also change. It is also necessary to make the aperture number of the zoom lens 100 adjustable within a range of greater than or equal to 1.68 and less than or equal to 4.95.

[0091] In a specific embodiment, each lens group must meet the following requirements: the zoom lens is in a wide-angle state, with a focal length F, F=4.4 mm; the focal length of the first lens group is f1, 0.048≤F / f1≤0.066; the focal length of the second lens group is f2, -0.738≤F / f2≤-0.546; the focal length of the third lens group is f3, 0.340≤F / f3≤0.460; the focal length of the fourth lens group is f4, -0.500≤F / f4≤-0.369; the focal length of the fifth lens group is f5, 0.286≤F / f5≤0.387; the focal length of the sixth lens group is f6, -0.421≤F / f6≤-0.311; and the focal length of the seventh lens group is f7, 0.207≤F / f7≤0.280.

[0092] Each lens group may include more than one lens. In order to achieve the focal length requirements of the lens group, each corresponding individual lens must meet the following requirements: the first lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side. The focal length of the first lens is f11, -1.283≤f1 / f11≤-0.948; the focal length of the second lens is f12, 0.858≤f1 / f12≤1.160; the focal length of the third lens is f13, 0.71 8≤f1 / f13≤0.971; the focal length of the fourth lens is f14, 0.884≤f1 / f14≤1.197; the second lens group includes a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side, the focal length of the fifth lens is f21, 0.533≤f2 / f21≤0.722; the focal length of the sixth lens is f22, 0.516≤f2 / f22≤0.698; the focal length of the seventh lens is f23, -0.381≤f2 / f23≤-0.282; the third lens group includes an eighth lens, the focal length of the eighth lens is f31, 0.833≤f3 / f31≤1.250; the fourth lens group includes a ninth lens, the focal length of the ninth lens is f41, 0.833≤f4 / f41≤1.250; the fifth lens group includes a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object side to the image side, the focal length of the tenth lens is f51, 0.871≤f5 / f51≤1. 179; the focal length of the eleventh lens is f52, -1.289≤f5 / f52≤-0.952; the focal length of the twelfth lens is f53, 0.934≤f5 / f53≤1.263; the sixth lens group includes a thirteenth lens, the focal length of the thirteenth lens is f61, 0.833≤f6 / f61≤1.250; the seventh lens group includes a fourteenth lens, the focal length of the fourteenth lens is f71, 0.833≤f7 / f71≤1.250.

[0093] The wide-angle state of the zoom lens 100 in the present invention (eg Figure 1 As shown), the imaging surface 9 has a size of Φ6.7 mm, a focal length of 4.4 mm, a distortion level of less than or equal to 1.46%, and an applicable wavelength range of 436 mm to 870 mm; the telephoto state of the zoom lens 100 (as shown Figure 2 As shown), the imaging surface 9 has a size of Φ6.7mm, a focal length of 169.4mm, a distortion degree of less than or equal to -3.30%, and an applicable band of 436mm-870mm.

[0094] In a specific embodiment, the parameters of each mirror group and lens are as follows:

[0095]

[0096] In the zoom lens 100, spherical lenses and aspherical lenses are usually used in combination. Spherical lenses can be used as basic elements for preliminary correction of aberrations, while aspherical lenses are used for fine adjustment to achieve higher optical performance. Through this combination, lens designers can maximize the imaging quality of the lens while maintaining cost-effectiveness. In summary, the use of different types of lenses in the zoom lens 100 is to balance cost, manufacturing complexity and optical performance. Spherical lenses provide basic optical functions, while aspherical lenses are used to improve and optimize these functions to achieve high-quality imaging effects together. In one embodiment, the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the sixth lens 22, the seventh lens 23, the eleventh lens 52, and the twelfth lens 53 are all set as spherical lenses; the fifth lens 21, the eighth lens 31, the ninth lens 41, the tenth lens 51, the thirteenth lens 61, and the fourteenth lens 71 are all set as aspherical lenses. Aspherical lenses are placed near the object side to reduce common distortions in wide-angle lenses, such as barrel distortion, making the image more realistic. They are placed near the image side to help improve the imaging quality of telephoto lenses, especially in areas far from the optical center. Aspherical lenses are used at specific zoom positions to compensate for specific aberrations that occur at that position.

[0097] In a specific embodiment (see the table below):

[0098]

[0099]

[0100]

[0101] Specifically, the surface shape of each aspheric lens can be defined by but not limited to the following aspheric formula:

[0102]

[0103] Among them, c is the curvature corresponding to the radius, y is the radial coordinate (its unit is the same as the lens length unit), k is the coefficient of the conic quadratic curve (when the k coefficient is less than -1, the surface curve is a hyperbola, when the k coefficient is equal to -1, it is a parabola, when the k coefficient is between -1 and 0, it is an ellipse, when the k coefficient is equal to 0, it is a circle, and when the k coefficient is greater than 0, it is an oblate circle), A, B, C, D, E, F are high-order aspheric coefficients, and the high-order coefficients of each aspheric mirror surface can be seen from the above table.

[0104] In order to optimize the optical performance of the lens, reduce aberrations, improve the imaging quality, simplify the manufacturing process and reduce costs. In one embodiment, the first lens 11 is bonded with the second lens 12, the sixth lens 22 is bonded with the seventh lens 23, and the eleventh lens 52 is bonded with the twelfth lens 53. The reason why the optical performance of the lens can be optimized, the aberration can be reduced, the imaging quality can be improved, the manufacturing process can be simplified and the cost can be reduced is that lenses of different materials will produce different degrees of refraction when passing through light of different colors, resulting in chromatic aberration. By bonding two or more lenses of different materials together, the chromatic aberration can be offset to obtain a clearer color image. When a single lens contacts the air, there will be a large reflection loss, while the reflection loss between the bonded lens and the glass is greatly reduced, thereby improving the transmission efficiency of light energy and increasing the brightness of the image. Bonding can compensate for the slight differences between the lenses, reduce the requirements for precision processing, and simplify the optical design. This helps to reduce manufacturing costs while maintaining high-quality imaging performance. The sealing layer formed during the bonding process can protect the surface of the optical parts, prevent the intrusion of dust and other particles, and extend the service life of the lens. Cemented lenses can combine two or more lenses into a single optical unit, which can reduce the spacing between lenses and improve optical performance, such as reducing spherical aberration and coma.

[0105] In the zoom lens 100, since the focal length of the lens changes, the degree of dispersion at different focal lengths will also be different. A lens with a high Abbe number can better control dispersion during zooming and maintain the color consistency of the image. However, a lens with a low Abbe number may have more obvious dispersion during zooming, affecting the clarity and color reproduction of the image. In one embodiment, the Abbe number of the first lens is V1, 32.00≤V1≤32.64; the Abbe number of the second lens is V2, 93.57≤V2≤95.47; the Abbe number of the third lens is V3, 80.79≤V3≤82.43; the Abbe number of the fourth lens is V4, 67.66≤V4≤69.02; the Abbe number of the fifth lens is V5, 49.02≤V5≤50.02; the Abbe number of the sixth lens is V6, 51.80≤V6≤52.84; the Abbe number of the seventh lens is V7, 17.76≤V7≤18.12; The Abbe number of the eighth lens is V8, 70.96≤V8≤72.40; the Abbe number of the ninth lens is V9, 66.35≤V9≤67.69; the Abbe number of the tenth lens is V10, 80.74≤V10≤82.38; the Abbe number of the eleventh lens is V11, 42.30≤V11≤43.16; the Abbe number of the twelfth lens is V12, 94.15≤V12≤96.05; the Abbe number of the thirteenth lens is V13, 49.01≤V13≤50.00; and the Abbe number of the fourteenth lens is V14, 80.74≤V14≤82.38.

[0106] The focal length of the zoom lens 100 is affected by many factors, one of which is the refractive index of the lens. The refractive index of a lens refers to the ratio of the speed at which light propagates in the lens material to the speed at which light propagates in a vacuum. The greater the refractive index, the more the propagation path of light in the lens is bent, resulting in the light converging earlier, i.e., the focal length becomes shorter. Therefore, the refractive index needs to satisfy: the refractive index of the first lens is N1, 1.9481≤N1≤1.9520; the refractive index of the second lens is N2, 1.4386≤N2≤1.4414; the refractive index of the third lens is N3, 1.4985≤N3≤1.5015; the refractive index of the fourth lens is N4, 1.5884≤N4≤1.5916; the refractive index of the fifth lens is N5, 1.7682≤N5≤1.7718; the refractive index of the sixth lens is N6, 1.7483≤N6≤1.7518; the refractive index of the seventh lens is N7, 1.9481≤N7≤1.9520; The refractive index of the eighth lens is N8, 1.5485≤N8≤1.5516; the refractive index of the ninth lens is N9, 1.5884≤N9≤1.5916; the refractive index of the tenth lens is N10, 1.4985≤N10≤1.5015; the refractive index of the eleventh lens is N11, 1.8282≤N11≤1.8318; the refractive index of the twelfth lens is N12, 1.4386≤N12≤1.4414; the refractive index of the thirteenth lens is N13, 1.7682≤N13≤1.7718; and the refractive index of the fourteenth lens is N14, 1.4985≤N14≤1.5015.

[0107] In order to ensure that the focal length of the zoom lens 100 is adjustable within a range of greater than or equal to 4.4 mm and less than or equal to 169.4 mm, the movably arranged lens group needs to have a corresponding movable stroke, wherein the total optical length of the zoom lens 100 is TTL, TTL≤96 mm; the movable stroke of the second lens group 2 in the optical axis direction is A1, A1≥28.1 mm and 0.255≤A1 / TTL≤0.331; the movable stroke of the fourth lens group 4 in the optical axis direction is A2, A2≥4.7 mm and 0.042≤A2 / TTL≤0.055; the movable stroke of the fifth lens group 5 in the optical axis direction is A3, A3≥8.3 mm and 0.075≤A3 / TTL≤0.098; and the movable stroke of the sixth lens group 6 in the optical axis direction is A4, A4≥12.1 mm and 0.109≤A4 / TTL≤0.142. The ratio of the distance from the aperture 8 to the imaging plane 9 to the total length affects the design flexibility and imaging performance of the lens. A smaller ratio means that the optical part of the lens occupies most of the total length, which may help to achieve a more compact design, but may also limit the focal length range and field of view of the lens. On the contrary, a larger ratio may mean that the optical part of the lens is shorter and the mechanical part is longer, which may allow a larger focal length variation range and a more flexible design, but may also result in a larger overall size of the lens. For the zoom lens 100 proposed in the present invention, the aperture 8 is arranged between the second lens group 2 and the third lens group 3; and the imaging plane 9 is located on the image side of the seventh lens group 7; wherein the distance from the aperture 8 to the imaging plane 9 is L, 0.448≤L / TTL≤0.538.

[0108] The utility model also proposes a monitoring device, which includes a zoom lens 100. The specific structure of the zoom lens 100 refers to the above embodiment. Since the monitoring device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one. The zoom lens 100 has an object side and an image side which are arranged opposite to each other along the optical axis direction. The zoom lens 100 includes a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4, a fifth lens group 5, a sixth lens group 6, and a seventh lens group 7 which are arranged in sequence from the object side to the image side. The first lens group 1, the third lens group 3, the fifth lens group 5, and the seventh lens group 7 have positive focal power, and the second lens group 2, the fourth lens group 4, and the sixth lens group 6 have negative focal power. The second lens group 2, the fourth lens group 4, and the fifth lens group 5 are movably arranged along the extension direction of the optical axis for zooming, and the sixth lens group 6 is movably arranged along the optical axis direction for focusing. The focal length of the zoom lens 100 is adjustable within a range of greater than or equal to 4.4 mm and less than or equal to 169.4 mm, and the aperture number of the zoom lens 100 is adjustable within a range of greater than or equal to 1.68 and less than or equal to 4.95.

[0109] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A zoom lens, characterized in that: The zoom lens has an object side and an image side which are arranged opposite to each other along the optical axis direction, and comprises a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, a sixth lens group, and a seventh lens group which are arranged in sequence from the object side to the image side; The first lens group, the third lens group, the fifth lens group, and the seventh lens group have positive refractive power, and the second lens group, the fourth lens group, and the sixth lens group have negative refractive power; Among them, the second lens group, the fourth lens group and the fifth lens group are movably arranged along the extension direction of the optical axis for zooming, and the sixth lens group is movably arranged along the optical axis direction for focusing; so that the focal length of the zoom lens is adjustable within the range of greater than or equal to 4.4 mm and less than or equal to 169.4 mm, and the aperture number of the zoom lens is adjustable within the range of greater than or equal to 1.68 and less than or equal to 4.

95.

2. The zoom lens according to claim 1, wherein: The zoom lens is in a wide-angle state, with a focal length F, F=4.4 mm; The focal length of the first lens group is f1, 0.048≤F / f1≤0.066; The focal length of the second lens group is f2, -0.738≤F / f2≤-0.546; The focal length of the third lens group is f3, 0.340≤F / f3≤0.460; The focal length of the fourth lens group is f4, -0.500≤F / f4≤-0.369; The focal length of the fifth lens group is f5, 0.286≤F / f5≤0.387; The focal length of the sixth lens group is f6, -0.421≤F / f6≤-0.311; The focal length of the seventh lens group is f7, 0.207≤F / f7≤0.

280.

3. The zoom lens according to claim 2, wherein: The first lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side, the focal length of the first lens is f11, -1.283≤f1 / f11≤-0.948; the focal length of the second lens is f12, 0.858≤f1 / f12≤1.160; the focal length of the third lens is f13, 0.718≤f1 / f13≤0.971; the focal length of the fourth lens is f14, 0.884≤f1 / f14≤1.197; The second lens group includes a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side, the focal length of the fifth lens is f21, 0.533≤f2 / f21≤0.722; the focal length of the sixth lens is f22, 0.516≤f2 / f22≤0.698; the focal length of the seventh lens is f23, -0.381≤f2 / f23≤-0.282; The third lens group includes an eighth lens, the focal length of the eighth lens is f31, 0.833≤f3 / f31≤1.250; The fourth lens group includes a ninth lens, the focal length of the ninth lens is f41, 0.833≤f4 / f41≤1.250; The fifth lens group includes a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object side to the image side, the focal length of the tenth lens is f51, 0.871≤f5 / f51≤1.179; the focal length of the eleventh lens is f52, -1.289≤f5 / f52≤-0.952; the focal length of the twelfth lens is f53, 0.934≤f5 / f53≤1.263; The sixth lens group includes a thirteenth lens, the focal length of the thirteenth lens is f61, 0.833≤f6 / f61≤1.250; The seventh lens group includes a fourteenth lens, and the focal length of the fourteenth lens is f71, 0.833≤f7 / f71≤1.

250.

4. The zoom lens according to claim 3, wherein: The first lens, the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, the eleventh lens, and the twelfth lens are all configured as spherical lenses; The fifth lens, the eighth lens, the ninth lens, the tenth lens, the thirteenth lens, and the fourteenth lens are all configured as aspherical lenses.

5. The zoom lens according to claim 3, wherein: The first lens is glued to the second lens, the sixth lens is glued to the seventh lens, and the eleventh lens is glued to the twelfth lens.

6. The zoom lens according to claim 3, wherein: The Abbe number of the first lens is V1, 32.00≤V1≤32.64; The Abbe number of the second lens is V2, 93.57≤V2≤95.47; The Abbe number of the third lens is V3, 80.79≤V3≤82.43; The Abbe number of the fourth lens is V4, 67.66≤V4≤69.02; The Abbe number of the fifth lens is V5, 49.02≤V5≤50.02; The Abbe number of the sixth lens is V6, 51.80≤V6≤52.84; The Abbe number of the seventh lens is V7, 17.76≤V7≤18.12; The Abbe number of the eighth lens is V8, 70.96≤V8≤72.40; The Abbe number of the ninth lens is V9, 66.35≤V9≤67.69; The Abbe number of the tenth lens is V10, 80.74≤V10≤82.38; the Abbe number of the eleventh lens is V11, 42.30≤V11≤43.16; the Abbe number of the twelfth lens is V12, 94.15≤V12≤96.05; the Abbe number of the thirteenth lens is V13, 49.01≤V13≤50.00; and the Abbe number of the fourteenth lens is V14, 80.74≤V14≤82.

38.

7. The zoom lens according to claim 3, wherein: The refractive index of the first lens is N1, 1.9481≤N1≤1.9520; The refractive index of the second lens is N2, 1.4386≤N2≤1.4414; The refractive index of the third lens is N3, 1.4985≤N3≤1.5015; The refractive index of the fourth lens is N4, 1.5884≤N4≤1.5916; The refractive index of the fifth lens is N5, 1.7682≤N5≤1.7718; The refractive index of the sixth lens is N6, 1.7483≤N6≤1.7518; The refractive index of the seventh lens is N7, 1.9481≤N7≤1.9520; The refractive index of the eighth lens is N8, 1.5485≤N8≤1.5516; The refractive index of the ninth lens is N9, 1.5884≤N9≤1.5916; The refractive index of the tenth lens is N10, 1.4985≤N10≤1.5015; The refractive index of the eleventh lens is N11, 1.8282≤N11≤1.8318; the refractive index of the twelfth lens is N12, 1.4386≤N12≤1.4414; the refractive index of the thirteenth lens is N13, 1.7682≤N13≤1.7718; the refractive index of the fourteenth lens is N14, 1.4985≤N14≤1.5015.

8. The zoom lens according to claim 1, wherein: The total optical length of the zoom lens is TTL, TTL≤96mm; The movable stroke of the second lens group in the optical axis direction is A1, A1≥28.1mm and 0.255≤A1 / TTL≤0.331; The movable stroke of the fourth lens group in the optical axis direction is A2, A2≥4.7mm and 0.042≤A2 / TTL≤0.055; The movable stroke of the fifth lens group in the optical axis direction is A3, A3≥8.3mm and 0.075≤A3 / TTL≤0.098; The movable stroke of the sixth lens group in the optical axis direction is A4, A4≥12.1mm and 0.109≤A4 / TTL≤0.

142.

9. The zoom lens according to claim 8, wherein: The zoom lens further comprises: an aperture, the aperture being disposed between the second lens group and the third lens group; and An imaging plane, located on the image side of the seventh lens group; Wherein, the distance from the aperture to the imaging surface is L, and 0.448≤L / TTL≤0.

538.

10. A monitoring device, characterized in that: Comprising the zoom lens as described in any one of claims 1 to 9.

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