Zoom lens and imaging device

Abstract

The present invention discloses a zoom lens and an imaging device. The zoom lens includes a lens barrel and a lens group. The lens group includes a front fixed group, a zoom group, a rear fixed group, a compensation group, and an image plane arranged in sequence from the object side to the image side. The zoom group and the compensation group move cooperatively along the optical axis direction. The compensation group is used to adjust the imaging distance when the zoom group zooms. When the external temperature changes, the lens itself will generate deformations such as expansion or contraction, causing the focal lengths of the respective lenses to change to a certain extent. Through the combination of the respective lenses, when the focal lengths of some of the lenses change due to deformation, the passive compensation for temperature defocus is achieved through the deformation of other lenses, so that the final imaging can still be clear without manual focusing, thereby improving the technical problem that the existing zoom lens cannot achieve consistent clear imaging throughout the zoom process when the ambient temperature changes.

Description

Technical Field

[0001] The present invention relates to the technical field of optical system design, and particularly relates to a zoom lens and an imaging device. Background Art

[0002] In recent years, due to the increasingly wide range of usage scenarios of monitoring devices and the increasingly complex working environments, the impact of environmental temperature changes on the devices cannot be ignored. Since traditional zoom optical systems cannot achieve consistent clear imaging throughout the zoom process when the environmental temperature changes, frequent focusing is required, and such optical systems cannot be widely applied in monitoring devices. Therefore, the design and development of a zoom lens with passive athermalization have become a necessity. Summary of the Invention

[0003] The main object of the present invention is to provide a zoom lens, aiming to improve the technical problem that existing zoom lenses cannot achieve consistent clear imaging throughout the zoom process when the environmental temperature changes.

[0004] To achieve the above object, the present invention provides a zoom lens. The zoom lens has an object side and an image side that are oppositely arranged along the optical axis direction. The zoom lens includes:

[0005] A lens barrel; and,

[0006] A lens group, the lens group includes a front fixed group, a zoom group, a rear fixed group, a compensation group, and an imaging surface that are sequentially arranged from the object side to the image side. Among them, the front fixed group and the rear fixed group are fixedly installed on the lens barrel, the zoom group and the compensation group are movably installed on the lens barrel along the optical axis direction, the zoom group and the compensation group move cooperatively along the optical axis direction, the compensation group is used to adjust the imaging distance when the zoom group changes magnification, and when the external temperature changes, the zoom lens is used to achieve passive compensation for temperature defocusing through the combination of each lens.

[0007] Optionally, the front fixed group includes a first lens and a second lens. The optical power of the first lens is negative, and the optical power of the second lens is positive;

[0008] The zoom group includes a third lens, a fourth lens, and a fifth lens. The optical power of the third lens is negative, the optical power of the fourth lens is negative, and the optical power of the fifth lens is positive;

[0009] The rear fixed group includes a sixth lens, a seventh lens, and an eighth lens. The optical power of the sixth lens is positive, the optical power of the seventh lens is negative, and the optical power of the eighth lens is positive;

[0010] The compensating group includes a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens. The optical power of the ninth lens is negative, the optical power of the tenth lens is positive, the optical power of the eleventh lens is positive, the optical power of the twelfth lens is positive, and the optical power of the thirteenth lens is negative.

[0011] Optionally, the refractive index of the first lens is n1, and n1 = 1.82;

[0012] The refractive index of the second lens is n2, and n2 = 1.44;

[0013] The refractive index of the third lens is n3, and n3 = 1.54;

[0014] The refractive index of the fourth lens is n4, and n4 = 1.64;

[0015] The refractive index of the fifth lens is n5, and n5 = 1.65;

[0016] The refractive index of the sixth lens is n6, and n6 = 1.54;

[0017] The refractive index of the seventh lens is n7, and n7 = 1.65;

[0018] The refractive index of the eighth lens is n8, and n8 = 1.57;

[0019] The refractive index of the ninth lens is n9, and n9 = 1.61;

[0020] The refractive index of the tenth lens is n10, and n10 = 1.65;

[0021] The refractive index of the eleventh lens is n11, and n11 = 1.85;

[0022] The refractive index of the twelfth lens is n12, and n12 = 1.61;

[0023] The refractive index of the thirteenth lens is n13, and n13 = 1.61.

[0024] Optionally, the Abbe number of the first lens is vd1, and vd1 = 42.7;

[0025] The Abbe number of the second lens is vd2, and vd2 = 94.5;

[0026] The Abbe number of the third lens is vd3, and vd3 = 55.9;

[0027] The Abbe number of the fourth lens is vd4, and vd4 = 23.0;

[0028] The Abbe number of the fifth lens is vd5, and vd5 = 21.5;

[0029] The dispersion coefficient of the sixth lens is vd6, and vd6 = 55.9;

[0030] The dispersion coefficient of the seventh lens is vd7, and vd7 = 33.9;

[0031] The dispersion coefficient of the eighth lens is vd8, and vd8 = 71.3;

[0032] The dispersion coefficient of the ninth lens is vd9, and vd9 = 25.6;

[0033] The dispersion coefficient of the tenth lens is vd10, and vd10 = 21.5;

[0034] The dispersion coefficient of the eleventh lens is vd11, and vd11 = 40.6;

[0035] The dispersion coefficient of the twelfth lens is vd12, and vd12 = 25.6;

[0036] The dispersion coefficient of the thirteenth lens is vd13, and vd13 = 25.6.

[0037] Optionally, the optical power of the first lens is φ11, where -0.0015 ≤ φ11 ≤ -0.0011;

[0038] The optical power of the third lens is φ21, where -0.070 ≤ φ21 ≤ -0.065;

[0039] The optical power of the sixth lens is φ31, where 0.081 ≤ φ31 ≤ 0.090;

[0040] The optical power of the ninth lens is φ41, where -0.132 ≤ φ41 ≤ -0.120.

[0041] Optionally, the first lens, the second lens, the seventh lens, the eighth lens, and the eleventh lens are spherical lenses;

[0042] The third lens, the fourth lens, the fifth lens, the sixth lens, the ninth lens, the tenth lens, the twelfth lens, and the thirteenth lens are aspherical lenses.

[0043] Optionally, the first lens, the second lens, the seventh lens, the eighth lens, and the eleventh lens are made of glass;

[0044] The third lens, the fourth lens, the fifth lens, the sixth lens, the ninth lens, the tenth lens, the twelfth lens, and the thirteenth lens are made of plastic.

[0045] Optionally, the first lens and the second lens are adhesively connected;

[0046] The seventh lens and the eighth lens are adhesively connected.

[0047] Optionally, the distance that the zoom group can move along the optical axis is set to L1 ≤ 19.644 mm, and the distance that the compensation group can move along the optical axis is set to L2 ≤ 0.4953 mm;

[0048] The zoom lens satisfies: Ft / Fw = 2.7, where Ft is the maximum focal length of the zoom lens and Fw is the minimum focal length of the zoom lens.

[0049] The present invention also provides an imaging device, and the imaging device includes the zoom lens described in the above solution.

[0050] In the technical solution provided by the present invention, the front fixed group and the rear fixed group are fixedly installed on the lens barrel, the zoom group and the compensation group are movably installed on the lens barrel along the optical axis direction, the front fixed group and the rear fixed group are fixedly installed on the lens barrel, the zoom group and the compensation group are movably installed on the lens barrel along the optical axis direction, the zoom group and the compensation group move cooperatively along the optical axis direction, the zoom group is used for zooming, the compensation group is used for adjusting the imaging distance when the zoom group changes magnification, when the zoom group and the compensation group move cooperatively along the optical axis direction so that the zoom lens zooms from the wide-angle end to the telephoto end, and the compensation group is driven by an external force to move along the optical axis for focusing corresponding to the position of the zoom group, the imaging wavelength, and the imaging object distance, so that the imaging surface of the zoom lens remains clear during the zooming process. When the external temperature changes, the lens itself will generate deformations such as expansion or contraction, so that the focal lengths of the lenses will change to a certain extent. The zoom lens, through the combination of the lenses, when the focal lengths of some of the lenses change due to deformation, realizes passive compensation for temperature defocus through the deformation of other lenses, so that the final imaging can still be clear without manual focusing, thereby improving the technical problem that the existing zoom lens cannot achieve consistent clear imaging throughout the zooming process when the environmental temperature changes. Description of the Drawings

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0052] Figure 1 Schematic cross-sectional structure diagram of the zoom lens provided by the present invention;

[0053] Figure 2 is Figure 1 Schematic diagrams of the zoom lens in when it is at the wide-angle end, intermediate magnification, and telephoto end;

[0054] Figure 3 is Figure 1 Modulation transfer function (MTF) curve diagram of the zoom lens in when it is at the wide-angle end at -30°C;

[0055] Figure 4 is Figure 1 Modulation transfer function (MTF) curve diagram of the zoom lens in when it is at the intermediate magnification at -30°C;

[0056] Figure 5 is Figure 1 Modulation transfer function (MTF) curve diagram of the zoom lens in when it is at the telephoto end at -30°C;

[0057] Figure 6 is Figure 1 Modulation transfer function (MTF) curve diagram of the zoom lens in when it is at the wide-angle end at +70°C;

[0058] Figure 7 is Figure 1 Modulation transfer function (MTF) curve diagram of the zoom lens in when it is at the intermediate magnification at +70°C;

[0059] Figure 8 is Figure 1 Modulation transfer function (MTF) curve diagram of the zoom lens in when it is at the telephoto end at +70°C.

[0060] Explanation of the reference numerals in the drawings:

[0061] Label Name Label Name 1 Front Fixed Group 32 Seventh Lens 11 First Lens 33 Eighth Lens 12 Second Lens 4 Compensation Group 2 Zoom Group 41 Ninth Lens 21 Third Lens 42 Tenth Lens 22 Fourth Lens 43 Eleventh Lens 23 Fifth Lens 44 Twelfth Lens 3 Rear Fixed Group 45 Thirteenth Lens 31 Sixth Lens 5 Imaging Plane

[0062] The realization, functional features, and advantages of the object of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. Specific embodiments

[0063] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0064] It should be noted that if there are directional indications in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0065] In addition, if there are descriptions such as "first" and "second" in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, or scenario B, or the scenario where A and B are satisfied simultaneously. Moreover, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0066] In recent years, due to the increasingly wide range of usage scenarios of monitoring devices and the increasingly complex working environments, the impact of environmental temperature changes on the devices cannot be ignored. Since traditional zoom optical systems cannot achieve consistent clear imaging throughout the zoom process when the environmental temperature changes, frequent focusing is required, and such optical systems cannot be widely applied in monitoring devices. Therefore, the design and development of a zoom lens with optical passive athermalization have become a necessity.

[0067] The present invention provides a zoom lens, aiming to improve the technical problem that the existing zoom lens cannot achieve consistent clear imaging throughout the zoom process when the environmental temperature changes. Please refer to Figures 1 to 8 , and the accompanying drawings show specific embodiments of the zoom lens.

[0068] Please refer to Figures 1 to 5 , the zoom lens has an object side and an image side that are relatively arranged along the optical axis direction. The zoom lens includes a lens barrel (not shown in the figure) and a lens group. The lens group includes a front fixed group 1, a zoom group 2, a rear fixed group 3, a compensation group 4, and an imaging surface 5 that are sequentially arranged from the object side to the image side. Among them, the front fixed group 1 and the rear fixed group 3 are fixedly installed on the lens barrel, the zoom group 2 and the compensation group 4 are movably installed on the lens barrel along the optical axis direction, the zoom group 2 and the compensation group 4 move cooperatively along the optical axis direction, and the compensation group 4 is used to adjust the imaging distance when the zoom group 2 changes magnification. When the external temperature changes, the zoom lens is used to achieve passive compensation for temperature defocusing through the combination of various lenses.

[0069] It should be noted that both the zoom group 2 and the compensation group 4 can be driven by an external force to move along the optical axis direction. Herein, the external force drive can be a drive motor drive or manual adjustment by a human, without limitation herein.

[0070] In the technical solution provided by the present invention, the front fixed group 1 and the rear fixed group 3 are fixedly installed on the lens barrel. The zoom group 2 and the compensation group 4 are movably installed on the lens barrel along the optical axis direction. The front fixed group 1 and the rear fixed group 3 are fixedly installed on the lens barrel. The zoom group 2 and the compensation group 4 are movably installed on the lens barrel along the optical axis direction. The zoom group 2 and the compensation group 4 move in coordination along the optical axis direction. The zoom group 2 is used for zooming, and the compensation group 4 is used for adjusting the imaging distance when the zoom group 2 changes magnification. When the zoom group 2 and the compensation group 4 move in coordination along the optical axis direction, so that the zoom lens zooms from the wide-angle end to the telephoto end, and the compensation group 4 is driven by an external force to move along the optical axis for moving focus corresponding to the position, imaging wavelength, and imaging object distance of the zoom group 2, so that the imaging surface 5 of the zoom lens remains clear during the zoom process. When the external temperature changes, the lens itself will generate deformations such as expansion or contraction, so that the focal lengths of the respective lenses will change to a certain extent. The zoom lens, through the combination of the respective lenses, when the focal lengths of some of the lenses change due to deformation, realizes passive compensation for temperature defocus through the deformation of other lenses, so that the final imaging can still be clear without manual focusing, so as to improve the technical problem that the existing zoom lens cannot achieve consistent clear imaging throughout the zoom process when the ambient temperature changes.

[0071] Specifically, in the present embodiment, the front fixed group 1 includes a first lens 11 and a second lens 12. The optical power of the first lens 11 is negative, and the optical power of the second lens 12 is positive. The zoom group 2 includes a third lens 21, a fourth lens 22, and a fifth lens 23. The optical power of the third lens 21 is negative, the optical power of the fourth lens 22 is negative, and the optical power of the fifth lens 23 is positive. The rear fixed group 3 includes a sixth lens 31, a seventh lens 32, and an eighth lens 33. The optical power of the sixth lens 31 is positive, the optical power of the seventh lens 32 is negative, and the optical power of the eighth lens 33 is positive. The compensation group 4 includes a ninth lens 41, a tenth lens 42, an eleventh lens 43, a twelfth lens 44, and a thirteenth lens 45. The optical power of the ninth lens 41 is negative, the optical power of the tenth lens 42 is positive, the optical power of the eleventh lens 43 is positive, the optical power of the twelfth lens 44 is positive, and the optical power of the thirteenth lens 45 is negative. It should be noted that the optical power is equal to the difference between the image-side beam convergence and the object-side beam convergence, and it characterizes the ability of the optical system to deflect light rays.

[0072] Specifically, in this embodiment, the refractive index of the first lens 11 is n1, where n1 = 1.82; the refractive index of the second lens 12 is n2, where n2 = 1.44; the refractive index of the third lens 21 is n3, where n3 = 1.54; the refractive index of the fourth lens 22 is n4, where n4 = 1.64; the refractive index of the fifth lens 23 is n5, where n5 = 1.65; the refractive index of the sixth lens 31 is n6, where n6 = 1.54; the refractive index of the seventh lens 32 is n7, where n7 = 1.65; the refractive index of the eighth lens 33 is n8, where n8 = 1.57; the refractive index of the ninth lens 41 is n9, where n9 = 1.61; the refractive index of the tenth lens 42 is n10, where n10 = 1.65; the refractive index of the eleventh lens 43 is n11, where n11 = 1.85; the refractive index of the twelfth lens 44 is n12, where n12 = 1.61; the refractive index of the thirteenth lens 45 is n13, where n13 = 1.61.

[0073] Specifically, in this embodiment, the Abbe number of the first lens 11 is vd1, where vd1 = 42.7; the Abbe number of the second lens 12 is vd2, where vd2 = 94.5; the Abbe number of the third lens 21 is vd3, where vd3 = 55.9; the Abbe number of the fourth lens 22 is vd4, where vd4 = 23.0; the Abbe number of the fifth lens 23 is vd5, where vd5 = 21.5; the Abbe number of the sixth lens 31 is vd6, where vd6 = 55.9; the Abbe number of the seventh lens 32 is vd7, where vd7 = 33.9; the Abbe number of the eighth lens 33 is vd8, where vd8 = 71.3; the Abbe number of the ninth lens 41 is vd9, where vd9 = 25.6; the Abbe number of the tenth lens 42 is vd10, where vd10 = 21.5; the Abbe number of the eleventh lens 43 is vd11, where vd11 = 40.6; the Abbe number of the twelfth lens 44 is vd12, where vd12 = 25.6; the Abbe number of the thirteenth lens 45 is vd13, where vd13 = 25.6.

[0074] More specifically, in this embodiment, the optical power of the first lens 11 is φ11, where -0.0015 ≤ φ11 ≤ -0.0011; the optical power of the third lens 21 is φ21, where -0.070 ≤ φ21 ≤ -0.065; the optical power of the sixth lens 31 is φ31, where 0.081 ≤ φ31 ≤ 0.090; the optical power of the ninth lens 41 is φ41, where -0.132 ≤ φ41 ≤ -0.120.

[0075] Specifically, in this embodiment, the first lens 11, the second lens 12, the seventh lens 32, the eighth lens 33, and the eleventh lens 43 are spherical lenses; by using spherical lenses, the cost can be reduced while ensuring image quality and reliability, the assembly sensitivity is relatively low, and the yield of finished products is improved.

[0076] Specifically, aspherical lenses have the advantages of being able to correct images, solve vision distortion, making the lenses lighter, thinner, and flatter. In this embodiment, the third lens 21, the fourth lens 22, the fifth lens 23, the sixth lens 31, the ninth lens 41, the tenth lens 42, the twelfth lens 44, and the thirteenth lens 45 are aspherical lenses. The characteristics of aspherical lenses are that the curvature changes continuously from the center of the lens to the periphery of the lens. Different from spherical lenses with a constant curvature from the center of the lens to the periphery of the lens, aspherical lenses have better curvature radius characteristics and have the advantages of improving distortion aberration and astigmatism aberration. After using aspherical lenses, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality of the lens. And by using lenses made of glass material, the influence of temperature on the optical performance of the lens can be reduced.

[0077] Specifically, because glass lenses have the advantages of high hardness, strong wear resistance, long service life, stable chemical properties, not being easily affected by thermal expansion and contraction to cause focus shift, and not being easily corroded, in this embodiment, the materials of the first lens 11, the second lens 12, the seventh lens 32, the eighth lens 33, and the eleventh lens 43 are glass. Glass lenses can well resist the problem of lens deformation caused by heat and maintain the high precision of the lens for a long time. Because plastic lenses have strong impact resistance, light weight, and low cost at the same time, in this embodiment, the materials of the third lens 21, the fourth lens 22, the fifth lens 23, the sixth lens 31, the ninth lens 41, the tenth lens 42, the twelfth lens 44, and the thirteenth lens 45 are plastic. By using multiple plastic aspherical lenses, they can be injection molded after mold opening, the overall structure of the equipment is light, and the cost is effectively controlled by using plastic aspherical lenses.

[0078] Specifically, in order to enable optical components to improve the image quality of the optical system, reduce light energy loss, increase imaging clarity, protect the scale surface, and further optimize the processing process to meet the design requirements, the first lens 11 and the second lens 12 are adhesively connected; the seventh lens 32 and the eighth lens 33 are adhesively connected.

[0079] Specifically, in this embodiment, the distance that the zoom group 2 can move along the optical axis direction is set to L1≤19.644 mm, and the distance that the compensation group 4 can move along the optical axis direction is set to L2≤0.4953 mm; the zoom lens satisfies: Ft / Fw = 2.7, where Ft is the maximum focal length of the zoom lens and Fw is the minimum focal length of the zoom lens. The zoom group 2 moves along the optical axis direction, and at the same time, the compensation group 4 moves along the optical axis direction. The zoom group 2 and the compensation group 4 move along the optical axis as shown by Figure 2 the dotted line to form a zoom curve, and 2.7X continuous zoom can be realized.

[0080] In this way, by reasonably designing the optical parameters and materials of each lens, the zoom lens can ensure clear imaging without refocusing in extreme environments. The system fully considers the matching of the change amounts of the refractive index and Abbe number of various lens materials at high and low temperatures with the change amounts of the surface shape and air gap, realizes the positive and negative matching of the change amounts of various elements such as high and low temperatures and humidity, and ensures the synchronization and clarity of the image plane in high and low temperature and different humidity environments. By reasonably distributing the lens optical power, adjusting the glass shape and material combination, effectively eliminating chromatic aberration and secondary spectrum, and making the spherical aberration, coma, astigmatism, etc. on each lens compensate and cancel each other to achieve the effect of clear imaging.

[0081] Specifically, the imaging surface 5 can be understood as the surface of the photosensitive chip facing the object side, that is, it can be the surface of a camera element such as a CCD or CMOS. It can be understood that the light carrying the information of the object to be photographed can pass through the front fixed group 1, the zoom group 2, the rear fixed group 3, the compensation group 4 in sequence and finally form an image on the imaging surface 5.

[0082] Specifically, in this embodiment, the parameters of the zoom lens are as follows:

[0083] The focal length at the wide-angle end fw = 10.2 mm, and the focal length at the telephoto end ft = 27.5 mm; the aperture number at the wide-angle end = 1.7, and the aperture number at the telephoto end = 1.8; the semi-field angle at the wide-angle end = 24°, and the semi-field angle at the telephoto end = 9.1°; the optical distortion range is between 0.5% and 10%, where the distortion size at the telephoto end is 0.5% and the distortion size at the wide-angle end is 10%; the total optical length TTL of the zoom lens = 60 mm.

[0084] Specifically, in this embodiment, the refractive index, radius of curvature, and thickness interval of the lens material are as shown in the following table:

[0085] Table 1 Parameters of the lens

[0086] Surface Number Surface Type Radius / mm Thickness / mm Optical Material S1 Standard 19.9725 1.1659 1.82，42.7 S2 Standard 15.1013 5.4639 1.44，94.5 S3 Standard Infinity D3 S4 Even Asphere 12.5018 0.9414 1.54，55.9 S5 Even Asphere 23.9098 0.2295 S6 Even Asphere 10.1933 1.7703 1.64，23.0 S7 Even Asphere 7.7253 1.4932 S8 Even Asphere 9.3787 1.3368 1.65，21.5 S9 Even Asphere 17.2085 D9 S10 Stop Infinity 0.1424 S11 Even Asphere 9.7439 5.5488 1.54，55.9 S12 Even Asphere -16.1312 0.1799 S13 Standard -116.4608 0.9695 1.65，33.9 S14 Standard 7.4624 4.2504 1.57，71.3 S15 Standard -13.0078 D15 S16 Even Asphere -13.4530 0.9260 1.61，25.6 S17 Even Asphere 5.775 0.25 S18 Even Asphere 5.0552 2.7187 1.65，21.5 S19 Even Asphere 18.7975 0.3436 S20 Standard -22.987 1.0891 1.85，40.6 S21 Standard -18.919 0.1609 S22 Even Asphere 5.13 0.9580 1.61，25.6 S23 Even Asphere 5.0098 0.9925 S24 Even Asphere 6.4126 0.9093 1.61，25.6 S25 Even Asphere 4.8968 D25 IMG Standard Infinity

[0087] The data in the table are a set of data for the zoom lens, including surface number, surface type, radius, thickness, and optical material; the positive and negative of the radius satisfy the basic sign rules of optics; each set of data in the optical material represents the refractive index and Abbe number of the material.

[0088] Furthermore, in this embodiment, the aspherical surface shape of the aspherical lens satisfies the following conditions:

[0089]

[0090] Where z represents the axial sagittal height of the aspherical surface in the Z direction; y represents the height of the aspherical surface; c represents the curvature of the fitted spherical surface, numerically the reciprocal of the radius of curvature, k is the conic quadratic curve coefficient (when the k coefficient is less than -1, the surface shape 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, when the k coefficient is greater than 0, it is an oblate circle), A, B, C, D, E, F are the high-order aspherical coefficients (please refer to Table 2 below), and the shape dimensions of the aspherical surfaces on the object side and image side of the lens can be set through the above parameters.

[0091] Table 2

[0092] Surface Number K A B C D E F S4 0 1.18E-03 -3.16E-05 5.89E-07 -6.79E-09 4.47E-11 -1.25E-13 S5 0 1.57E-03 -4.27E-05 1.01E-06 -1.66E-08 1.11E-10 2.36E-13 S6 0 1.67E-04 -1.56E-05 4.41E-07 -8.55E-09 8.16E-11 -1.24E-13 S7 0 -1.19E-03 2.60E-05 -1.48E-06 3.92E-08 -5.09E-10 2.27E-12 S8 0 -1.18E-03 1.62E-05 -6.01E-07 -1.01E-08 5.45E-10 -4.86E-12 S9 0 -5.34E-04 2.97E-06 -2.36E-07 -7.77E-09 3.84E-10 -3.55E-12 S10 0 -1.48E-04 2.87E-06 -1.85E-07 6.28E-09 -6.10E-11 -5.65E-13 S12 0 3.10E-04 9.54E-06 -8.15E-07 3.80E-08 -8.20E-10 6.59E-12 S13 0 1.06E-03 -5.90E-05 6.74E-07 1.03E-07 -4.84E-09 6.46E-11 S17 0 -5.03E-04 -7.45E-05 4.36E-07 2.37E-07 -1.15E-08 1.64E-10 S18 0 -1.75E-03 -2.13E-05 5.98E-07 7.05E-08 -4.50E-09 5.20E-11 S19 0 -3.70E-03 1.46E-04 -3.53E-06 7.02E-08 -2.25E-09 3.26E-11 S20 0 -5.42E-03 -4.93E-05 -4.19E-06 2.86E-07 1.88E-09 -2.38E-10 S23 0 -4.45E-03 1.48E-04 -2.75E-05 2.03E-06 -9.27E-08 1.85E-09 S24 0 -1.06E-02 5.50E-04 -9.42E-06 -3.48E-07 -2.02E-08 1.33E-09 S25 0 -1.10E-02 5.64E-04 -1.54E-05 -5.80E-07 4.77E-08 -1.02E-09

[0093] As shown in Table 3 are the thickness values of each focal length segment in the example shown in Table 1, where the WIDE column represents the values of the variable parameters when the lens is at the minimum focal length, the TELE column represents the values of the variable parameters when the lens is at the maximum focal length, and the MID column represents a certain focal length segment between the maximum and minimum focal lengths of the lens.

[0094] Wide MID TELE D3 0.4998 14.1675 20.1435 D9 408.4376 6.8098 20.5089 D15 0.4989 0.9881 0.5029 D25 3.9683 3.5180 3.9689

[0095] In this embodiment, please refer to Figure 2 , which are the structural schematic diagrams of the zoom lens when it is at the wide-angle end, at the intermediate magnification, and at the telephoto end; among them, the intermediate magnification can be understood as the position schematic diagram of each lens group in the zoom lens when the zoom lens is between the wide-angle end and the telephoto end.

[0096] Figures 3 to 5 Respectively show the modulation transfer function (MTF) curve graphs of the zoom lens when it is at the wide-angle end, at the intermediate magnification, and at the telephoto end at -30°C;

[0097] Figures 6 to 8 Respectively show the modulation transfer function (MTF) curve graphs of the zoom lens when it is at the wide-angle end, at the intermediate magnification, and at the telephoto end at +70°C.

[0098] As can be seen from the above figures, when the zoom lens in this embodiment is at the middle magnification, wide-angle end, and telephoto end respectively, the modulation transfer function (MTF) value is greater than 0.2 @ 168 lp / mm, enabling clear imaging.

[0099] In addition, the present invention further provides an imaging device, which includes the zoom lens described in the above technical solution. The specific structure of this zoom lens refers to the above embodiment. Since the zoom lens of this imaging device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0100] The above are only optional embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made using the content of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is 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 that are oppositely arranged along the optical axis direction, and the zoom lens includes: A lens barrel; and, A lens group, the lens group includes a front fixed group, a zoom group, a rear fixed group, a compensation group, and an imaging surface that are sequentially arranged from the object side to the image side. Among them, the front fixed group and the rear fixed group are fixedly installed on the lens barrel, the zoom group and the compensation group are movably installed on the lens barrel along the optical axis direction, the zoom group and the compensation group move cooperatively along the optical axis direction, and the compensation group is used to adjust the imaging distance when the zoom group changes magnification. When the external temperature changes, the zoom lens is used to achieve passive compensation for temperature defocus through the combination of each lens; The front fixed group includes a first lens and a second lens, the optical power of the first lens is negative, and the optical power of the second lens is positive; The zoom group includes a third lens, a fourth lens, and a fifth lens, the optical power of the third lens is negative, the optical power of the fourth lens is negative, and the optical power of the fifth lens is positive; The rear fixed group includes a sixth lens, a seventh lens, and an eighth lens, the optical power of the sixth lens is positive, the optical power of the seventh lens is negative, and the optical power of the eighth lens is positive; The compensation group includes a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens, the optical power of the ninth lens is negative, the optical power of the tenth lens is positive, the optical power of the eleventh lens is positive, the optical power of the twelfth lens is positive, and the optical power of the thirteenth lens is negative; The refractive index of the first lens is n1, and n1 = 1.82; The refractive index of the second lens is n2, and n2 = 1.44; The refractive index of the third lens is n3, and n3 = 1.54; The refractive index of the fourth lens is n4, and n4 = 1.64; The refractive index of the fifth lens is n5, and n5 = 1.65; The refractive index of the sixth lens is n6, and n6 = 1.54; The refractive index of the seventh lens is n7, and n7 = 1.65; The refractive index of the eighth lens is n8, and n8 = 1.57; The refractive index of the ninth lens is n9, and n9 = 1.61; The refractive index of the tenth lens is n10, and n10 = 1.65; The refractive index of the eleventh lens is n11, and n11 = 1.85; The refractive index of the twelfth lens is n12, and n12 = 1.61; The refractive index of the thirteenth lens is n13, and n13 = 1.61; The materials of the first lens, the second lens, the seventh lens, the eighth lens, and the eleventh lens are glass; The materials of the third lens, the fourth lens, the fifth lens, the sixth lens, the ninth lens, the tenth lens, the twelfth lens, and the thirteenth lens are plastic.

2. The zoom lens according to claim 1, wherein, The dispersion coefficient of the first lens is vd1, and vd1 = 42.7; The dispersion coefficient of the second lens is vd2, and vd2 = 94.5; The dispersion coefficient of the third lens is vd3, and vd3 = 55.9; The dispersion coefficient of the fourth lens is vd4, where vd4 = 23.0; The dispersion coefficient of the fifth lens is vd5, where vd5 = 21.5; The dispersion coefficient of the sixth lens is vd6, where vd6 = 55.9; The dispersion coefficient of the seventh lens is vd7, where vd7 = 33.9; The dispersion coefficient of the eighth lens is vd8, where vd8 = 71.3; The dispersion coefficient of the ninth lens is vd9, where vd9 = 25.6; The dispersion coefficient of the tenth lens is vd10, where vd10 = 21.5; The dispersion coefficient of the eleventh lens is vd11, where vd11 = 40.6; The dispersion coefficient of the twelfth lens is vd12, where vd12 = 25.6; The dispersion coefficient of the thirteenth lens is vd13, where vd13 = 25.

6.

3. The zoom lens according to claim 1, wherein The optical power of the first lens is φ11, where -0.0015 ≤ φ11 ≤ -0.0011; The optical power of the third lens is φ21, where -0.070 ≤ φ21 ≤ -0.065; The optical power of the sixth lens is φ31, where 0.081 ≤ φ31 ≤ 0.090; The optical power of the ninth lens is φ41, where -0.132 ≤ φ41 ≤ -0.

120.

4. The zoom lens according to claim 1, characterized in that, The first lens, the second lens, the seventh lens, the eighth lens, and the eleventh lens are spherical lenses; The third lens, the fourth lens, the fifth lens, the sixth lens, the ninth lens, the tenth lens, the twelfth lens, and the thirteenth lens are aspherical lenses.

5. The zoom lens according to claim 1, characterized in that, The first lens and the second lens are adhesively connected; The seventh lens and the eighth lens are adhesively connected.

6. The zoom lens according to claim 1, wherein The distance that the zoom group can move along the optical axis direction is set to L1 ≤ 19.644 mm, and the distance that the compensation group can move along the optical axis direction is set to L2 ≤ 0.4953 mm; The zoom lens satisfies: Ft / Fw = 2.7, where Ft is the maximum focal length of the zoom lens and Fw is the minimum focal length of the zoom lens.

7. An imaging device, characterized in that, The imaging device includes the zoom lens according to any one of claims 1 to 6.

Images