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 first lens group, a second lens group, a third lens group, and a fourth lens group, which are arranged in sequence from the object side to the image side. The four lens groups include thirteen lenses. Among them, the material of the fourth lens, the fifth lens, the sixth lens, the eighth lens, the ninth lens, and the thirteenth lens are all set to plastic. Through the reasonable arrangement of the four lens groups, the conditional restriction of the focal length of the zoom lens at the wide-angle end and the focal length ratio of each lens group, and the reasonable selection of plastic aspherical lenses, a low-cost zoom lens is provided.

Description

Technical Field

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

[0002] The mainstream high-quality zoom lenses currently on the market for surveillance systems typically utilize multiple glass aspherical lenses to enhance resolution, but this results in high manufacturing costs. As zoom lenses for surveillance systems are becoming more affordable and suitable for home use, these high-cost lenses are no longer able to meet market demand. Summary of the Invention

[0003] The main purpose of the present invention is to provide a zoom lens and an imaging device, aiming to provide a low-cost zoom lens.

[0004] To achieve the above object, the present invention provides a zoom lens having an object side and an image side disposed opposite to each other along an optical axis. The zoom lens includes a lens barrel and a plurality of lens groups disposed within the lens barrel. The plurality of lens groups include:

[0005] a first lens group fixedly disposed in the lens barrel, the first lens group comprising a first lens and a second lens arranged in sequence from the object side to the image side;

[0006] a second lens group movably arranged along an extension direction of the optical axis so as to enable the zoom lens to zoom from a wide-angle end to a telephoto end when moving toward the image side, the second lens group comprising a third lens, a fourth lens, and a fifth lens arranged in sequence from the object side to the image side;

[0007] A third lens group is fixed in the lens barrel, the third lens group including a sixth lens; and

[0008] a fourth lens group movably arranged along an extension direction of the optical axis to focus the zoom lens when moving along the optical axis, the fourth lens group comprising a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens, arranged in order from the object side to the image side;

[0009] Wherein, the fourth lens, the fifth lens, the sixth lens, the eighth lens, the ninth lens, and the thirteenth lens are configured as plastic aspheric lenses.

[0010] Optionally, the optical focal power of the first lens group is positive, the optical focal power of the second lens group is negative, the optical focal power of the third lens group is positive, and the optical focal power of the fourth lens group is positive;

[0011] Among them, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the zoom lens satisfies the following conditions:

[0012] 0.098 < fw / f1 < 0.147, and -0.769 < fw / f2 < -0.513, and 0.114 < fw / f3 < 0.171, and 0.363 < fw / f4 < 0.545.

[0013] Optionally, the first lens has a negative optical power, and the second lens has a positive optical power;

[0014] The first lens and the second lens are adhesively connected;

[0015] The focal length of the first lens is f11, the focal length of the second lens is f12, and the lenses within the first lens group satisfy the following conditions:

[0016] -0.939 < f1 / f11 < -0.626, and 1.496 < f1 / f12 < 2.243.

[0017] Optionally, the third lens has a negative optical power, the fourth lens has a positive optical power, and the fifth lens has a negative optical power;

[0018] The focal length of the third lens is f21, the focal length of the fourth lens is f22, the focal length of the fifth lens is f23, and the lenses within the second lens group satisfy the following conditions:

[0019] 0.779 < f2 / f21 < 1.168, and -0.479 < f2 / f22 < -0.319, and 0.336 < f2 / f23 < 0.504.

[0020] Optionally, the sixth lens has a positive optical power.

[0021] Optionally, the seventh lens has a positive optical power, the eighth lens has a positive optical power, the ninth lens has a negative optical power, the tenth lens has a positive optical power, the eleventh lens has a positive optical power, the twelfth lens has a negative optical power, and the thirteenth lens has a negative optical power;

[0022] The focal length of the seventh lens is f41, the focal length of the eighth lens is f42, the focal length of the ninth lens is f43, the focal length of the tenth lens is f44, the focal length of the eleventh lens is f45, the focal length of the twelfth lens is f46, the focal length of the thirteenth lens is f47, and the lenses within the fourth lens group satisfy the following conditions:

[0023] 0.649 < f4 / f41 < 0.973, and 0.61 < f4 / f42 < 0.915, and -1.31 < f4 / f43 < -0.873, and 0.699 < f4 / f44 < 1.049, and 1.139 < f4 / f45 < 1.709, and -2.251 < f4 / f46 < -1.501, and -0.246 < f4 / f47 < -0.164.

[0024] Optionally, the first lens, the second lens, the third lens, the seventh lens, the tenth lens, the eleventh lens, and the twelfth lens are all glass spherical lenses.

[0025] Optionally, the zoom lens satisfies the following conditions:

[0026] Wherein, is the effective aperture of the first lens, and TTL is the overall optical length of the zoom lens.

[0027] Optionally, the zoom lens satisfies the following conditions: 0.233 < ΔZ W-T / TTL < 0.303;

[0028] Wherein, ΔZ W-T is the relative displacement of the second lens group when the zoom lens is in the wide-angle end position and the telephoto end position, and TTL is the overall optical length of the zoom lens.

[0029] The present invention also provides an imaging device, the imaging device includes a zoom lens, the zoom lens has an object side and an image side arranged oppositely along the optical axis direction, the zoom lens includes a lens barrel and a plurality of lens groups arranged in the lens barrel, the plurality of lens groups include:

[0030] A first lens group, fixedly arranged in the lens barrel, the first lens group includes a first lens and a second lens arranged in sequence from the object side to the image side;

[0031] A second lens group, movably arranged along the extension direction of the optical axis, so that when moving towards the image side, the zoom lens zooms from the wide-angle end to the telephoto end, the second lens group includes a third lens, a fourth lens, and a fifth lens arranged in sequence from the object side to the image side;

[0032] A third lens group, fixedly arranged in the lens barrel, the third lens group includes a sixth lens; and,

[0033] a fourth lens group movably arranged along an extension direction of the optical axis to focus the zoom lens when moving along the optical axis, the fourth lens group comprising a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens, arranged in order from the object side to the image side;

[0034] Wherein, the fourth lens, the fifth lens, the sixth lens, the eighth lens, the ninth lens, and the thirteenth lens are configured as plastic aspheric lenses.

[0035] In the technical solution provided by the present invention, the second lens group and the fourth lens group are movably mounted on the lens barrel along the optical axis, the second lens group is used for zooming, and the fourth lens group moves cooperatively along the optical axis to perform mobile focusing corresponding to the position, imaging wavelength, and imaging object distance of the second lens group, so that the zoom lens maintains clear imaging on the image plane during the zooming process. Among the four lens groups, the materials of the fourth lens, the fifth lens, the sixth lens, the eighth lens, the ninth lens, and the thirteenth lens are all set to plastic. Through the reasonable arrangement of the four lens groups and the conditional restrictions on the focal length of the zoom lens at the wide-angle end and the focal length ratio of each lens group, as well as the reasonable selection of plastic aspheric lenses, a solution of mixing glass spherical surfaces and plastic aspheric surfaces is used to provide a low-cost zoom lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 the structures shown in these drawings without paying any creative work.

[0037] Figure 1 A schematic structural diagram of the first embodiment of the zoom lens provided by the present invention when it is at the wide-angle end;

[0038] Figure 2 This is a structural diagram of the zoom lens at an intermediate magnification;

[0039] Figure 3 This is a schematic diagram of the structure of the zoom lens at the telephoto end;

[0040] Figure 4 for Figure 1 Aberration diagram of the zoom lens at the wide-angle end;

[0041] Figure 5 for Figure 1 Field curvature / distortion diagram of the zoom lens at the wide-angle end;

[0042] Figure 6 for Figure 2 Spherical aberration diagram of the zoom lens at intermediate magnifications;

[0043] Figure 7 for Figure 2 Field curvature / distortion diagram for the zoom lens at intermediate magnifications;

[0044] Figure 8 for Figure 3 Aberration diagram of the zoom lens at the telephoto end;

[0045] Figure 9 for Figure 3 Field curvature / distortion diagram of the zoom lens at the telephoto end.

[0046] Description of Figure Numbers:

[0047]

[0048]

[0049] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] It should be noted that if a directional indication is involved in an embodiment of the present invention, the directional indication is 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 indication will also change accordingly.

[0052] In addition, if there are descriptions involving "first", "second", etc. 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 number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. 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 it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0053] The mainstream high-quality zoom lenses currently on the market for surveillance systems typically utilize multiple glass aspherical lenses to enhance resolution, but this results in high manufacturing costs. As zoom lenses for surveillance systems are becoming more affordable and suitable for home use, these high-cost lenses are no longer able to meet market demand.

[0054] The present invention provides a zoom lens, which is a low-cost zoom lens. Figures 1 to 9 , the accompanying drawings show a specific embodiment of the zoom lens.

[0055] Figures 1 to 9 This is an embodiment of the zoom lens provided by the present invention.

[0056] Please refer to Figures 1 to 3, the zoom lens has an object side and an image side which are arranged opposite to each other along the optical axis, the zoom lens includes a lens barrel (not shown in the figure) and a plurality of lens groups, the lens barrel is extended along the optical axis, the lens groups are arranged in the lens barrel, the plurality of lens groups include a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4 and an image plane 5 which are arranged in sequence from the object side to the image side, the first lens group 1 is fixed in the lens barrel, the first lens group 1 includes a first lens 11 and a second lens 12 which are arranged in sequence from the object side to the image side; the second lens group 2 is movably arranged along the extension direction of the optical axis, so that the zoom lens can zoom from the wide-angle end to the telephoto end when it moves toward the image side, the second lens group 2 includes A third lens 21, a fourth lens 22, and a fifth lens 23 are sequentially arranged from the object side to the image side; the third lens group 3 is fixed in the lens barrel, and the third lens group 3 includes a sixth lens 31; the fourth lens group 4 is movably arranged along the extension direction of the optical axis to focus the zoom lens when moving along the optical axis, and the fourth lens group 4 includes a seventh lens 41, an eighth lens 42, a ninth lens 43, a tenth lens 44, an eleventh lens 45, a twelfth lens 46, and a thirteenth lens 47, which are sequentially arranged from the object side to the image side; wherein the fourth lens 22, the fifth lens 23, the sixth lens 31, the eighth lens 42, the ninth lens 43, and the thirteenth lens 47 are configured as plastic aspheric lenses.

[0057] It should be noted that the second lens group 2 is used to zoom when it moves along the extension direction of the optical axis, and the fourth lens group 4 is driven by an external force to move and focus along the optical axis corresponding to the position, imaging wavelength, and imaging object distance of the second lens group 2, so that the zoom lens maintains a clear image on the image plane 5 during the zooming process.

[0058] It should also be noted that the second lens group 2 and the fourth lens group 4 can be driven by external force to move along the optical axis, wherein the external force can be driven by a driving motor or manually adjusted without limitation.

[0059] In the technical solution provided by the present invention, among the four lens groups, the fourth lens 22, the fifth lens 23, the sixth lens 31, the eighth lens 42, the ninth lens 43, and the thirteenth lens 47 are all made of plastic. Through the reasonable arrangement of the four lens groups, the conditional restriction of the focal length of the zoom lens at the wide-angle end and the focal length ratio of each lens group, and the reasonable selection of plastic aspherical lenses, a solution of mixing glass spherical surfaces and plastic aspherical surfaces is used to provide a low-cost zoom lens.

[0060] It should be noted that in the prior art, in order to enable the zoom lens of the monitoring device to achieve high performance, usually for each lens, whether it is a spherical lens or an aspherical lens, a lens made of high-cost glass material is used, and the manufacturing cost of the glass aspherical lens is even higher. In order to enable the zoom lens to achieve the required performance, the fourth lens 22, the fifth lens 23, the sixth lens 31, the eighth lens 42, the ninth lens 43, and the thirteenth lens 47, which are set as aspherical lenses in the zoom lens, are set as plastic lenses, so as to achieve the purpose of reducing the manufacturing cost.

[0061] It should also be noted that the characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality of the lens. And using a lens made of glass material can reduce the influence of temperature on the optical performance of the lens.

[0062] Specifically, the optical power of the first lens group 1 is positive, the optical power of the second lens group 2 is negative, the optical power of the third lens group 3 is positive, and the optical power of the fourth lens group 4 is positive; where the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group 1 is f1, the focal length of the second lens group 2 is f2, the focal length of the third lens group 3 is f3, the focal length of the fourth lens group 4 is f4, and the zoom lens satisfies the following conditions:

[0063] 0.098 < fw / f1 < 0.147, and -0.769 < fw / f2 < -0.513, and 0.114 < fw / f3 < 0.171, and 0.363 < fw / f4 < 0.545.

[0064] In this embodiment, the ratio of the focal length of the zoom lens at the wide-angle end to the focal lengths of each lens group is as follows:

[0065] fw / f1 = 0.118; fw / f2 = 0.118; fw / f3 = 0.118; fw / f4 = 0.436.

[0066] Specifically, the first lens 11 has a negative optical power, and the second lens 12 has a positive optical power; the first lens 11 and the second lens 12 are adhesively connected; the focal length of the first lens 11 is f11, the focal length of the second lens 12 is f12, and the lenses in the first lens group 1 satisfy the following conditions:

[0067] -0.939 < f1 / f11 < -0.626, and 1.496 < f1 / f12 < 2.243.

[0068] More specifically, in this embodiment, the first lens 11 is a convex-concave spherical lens with a negative focal power, that is, the object side of the first lens 11 is convex and the image side is concave. The second lens 12 is a convex-concave spherical lens with a positive focal power, that is, the object side of the second lens 12 is convex and the image side is concave. The focal length ratios of the first lens group 1 to each lens therein are specifically as follows: f1 / f11 = -0.752; f1 / f12 = 1.795.

[0069] More specifically, in this embodiment, the focal length values of the first lens group 1 and each lens in the first lens group 1 are: f1 = 42.5; f11 = -56.608; f12 = 23.704.

[0070] Specifically, the third lens 21 has a negative focal power, the fourth lens 22 has a positive focal power, and the fifth lens 23 has a negative focal power; the focal length of the third lens 21 is f21, the focal length of the fourth lens 22 is f22, and the focal length of the fifth lens 23 is f23. Each lens in the second lens group 2 satisfies the following conditions:

[0071] 0.779 < f2 / f21 < 1.168, and -0.479 < f2 / f22 < -0.319, and 0.336 < f2 / f23 < 0.504.

[0072] More specifically, in this embodiment, the third lens 21 is a convex-concave spherical lens with a negative focal power, that is, the object side of the third lens 21 is convex and the image side is concave. The fourth lens 22 is a biconvex aspherical lens with a positive focal power, and the fifth lens 23 is a biconcave aspherical lens; the focal length ratios of the second lens group 2 to each lens therein are as follows:

[0073] f2 / f21 = 0.935; f2 / f22 = -0.383; f2 / f23 = 0.403.

[0074] More specifically, in this embodiment, the focal length values of the second lens group 2 and each lens in the second lens group 2 are: f2 = -8.1; f21 = -8.697; f22 = 21.211; f23 = -20.143.

[0075] Specifically, the sixth lens 31 has a positive focal power, f3 = 36.551; f31 = 36.551. [[ID=More specifically, the sixth lens 31 is a convex-concave aspherical lens with a positive optical power, that is, the object side of the sixth lens 31 is convex and the image side is concave.

[0077] Specifically, the seventh lens 41 has a positive optical power, the eighth lens 42 has a positive optical power, the ninth lens 43 has a negative optical power, the tenth lens 44 has a positive optical power, the eleventh lens 45 has a positive optical power, the twelfth lens 46 has a negative optical power, and the thirteenth lens 47 has a negative optical power; the focal length of the seventh lens 41 is f41, the focal length of the eighth lens 42 is f42, the focal length of the ninth lens 43 is f43, the focal length of the tenth lens 44 is f44, the focal length of the eleventh lens 45 is f45, the focal length of the twelfth lens 46 is f46, and the focal length of the thirteenth lens 47 is f47. The following conditions are satisfied for each lens in the fourth lens group 4:

[0078] 0.649 < f4 / f41 < 0.973, and 0.61 < f4 / f42 < 0.915, and -1.31 < f4 / f43 < -0.873, and 0.699 < f4 / f44 < 1.049, and 1.139 < f4 / f?45 < 1.709, and -2.251 < f4 / f46 < -1.501, and -0.246 < f4 / f47 < -0.164.

[0079] More specifically, in this embodiment, the seventh lens 41 is a biconvex spherical lens with a positive optical power, the eighth lens 42 is a biconvex aspherical lens with a positive optical power, the ninth lens 43 is a biconcave aspherical lens with a negative optical power, the tenth lens 44 is a biconvex spherical lens with a positive optical power, the eleventh lens 45 is a spherical lens with a positive optical power, the twelfth lens 46 is a biconcave spherical lens with a negative optical power, and the thirteenth lens 47 is a convex-concave aspherical lens with a negative optical power; the ratio of the focal length of the fourth lens group 4 to the focal length of each of its lenses is as follows:

[0080] f4 / f41 = 0.779; f4 / f42 = 0.732; f4 / f43 = -1.048; f4 / f44 = 0.839; [[ID=?14]]

[0081] f4 / f45 = 1.367; f4 / f47 = -1.801; f4 / f46 = -0.197.

[0082] It should be noted that there seems to be a typo in your original text where "f4 / f?45" is written. I translated it as "f4 / f45" based on the context. If this is not what you intended, please correct the original text.More specifically, in this embodiment, the focal length values ​​of the third lens group 33 and each lens in the third lens group 33 are: f4=11.5; f41=14.731; f42=15.669; f43=-10.945; f44=13.672; f45=8.389; f46=-6.369; and f47=-58.258.

[0083] Specifically, to ensure the stability of the zoom lens against temperature fluctuations, the first lens 11, the second lens 12, the third lens 21, the seventh lens 41, the tenth lens 44, the eleventh lens 45, and the twelfth lens 46 are all glass spherical lenses. Because glass lenses are less susceptible to thermal expansion and contraction, resulting in focus shift, they are well resistant to thermal deformation, maintaining high lens precision over time. Furthermore, the use of spherical lenses reduces costs while ensuring image quality and reliability, reduces assembly sensitivity, and improves product yield.

[0084] Furthermore, in order to reduce light energy loss, increase imaging clarity, protect the scale surface, and further optimize the processing flow to meet design requirements, in this embodiment, the first lens 11 and the second lens 12 are glued together to form a first glued lens. In this way, the glued parts are used rationally to allow optical components to improve the image quality of the optical system.

[0085] This setting, through the reasonable distribution of lens optical power, adjustment of glass shape and material matching, effectively eliminates chromatic aberration and secondary spectrum, so that the spherical aberration, coma, astigmatism, etc. on each lens compensate and offset each other to achieve a clear imaging effect, and realize the optimal correction of high-order aberrations and chromatic aberrations.

[0086] Specifically, in this embodiment, the refractive index, curvature radius, and thickness interval of the lens material are shown in the following table:

[0087]

[0088]

[0089] Furthermore, in this embodiment, the aspheric surface shape of the aspheric lens satisfies the following conditions:

[0090]

[0091] Where 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 conic coefficient (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), A, B, C, D, E, F, and G are high-order aspheric coefficients (please refer to Table 2 below). The above parameters can be used to set the shape and size of the lens object side and image side aspheric surfaces.

[0092] Table 2 Conic coefficients and aspheric coefficients corresponding to aspheric lenses

[0093]

[0094]

[0095] Specifically, the zoom lens further includes an aperture, and the aperture is located between the third lens group 3 and the fourth lens group 4 ; that is, the aperture is located between the sixth lens 31 and the seventh lens 41 .

[0096] Specifically, in this embodiment, the zoom lens further includes a filter, which is located between the fourth lens group 22 and the image plane. The filter is used to filter out light of unnecessary wavelengths and stray light to reduce optical noise and ease difficulties for subsequent photoelectric module processing. The filter can also be used to adjust the color of the object during the final imaging, thereby improving the imaging quality.

[0097] Specifically, the image plane 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 information of the object can pass through the first lens group 1, the second lens group 2, the third lens group 3, the aperture 6, the fourth lens group 4, the filter in sequence and finally form an image on the image plane 5.

[0098] Specifically, the zoom lens meets the following conditions: in, is the effective clear aperture of the first lens 11, and TTL is the total optical length of the zoom lens.

[0099] Specifically, the zoom lens satisfies the following conditions: 0.233<ΔZ W-T / TTL<0.303; where ΔZ W-T is the relative displacement of the second lens group 2 when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

[0100] Specifically, the zoom lens achieves the following performance parameters:

[0101] The focal length fw at the wide-angle end is 5mm, the focal length ft at the telephoto end is 25mm; the aperture number at the wide-angle end is 1.87, the aperture number at the telephoto end is 2.87; the optical distortion range is between -13% and 13%; the total optical length TTL of the zoom lens is 53mm.

[0102] Table 3 Zoom data of the zoom lens at wide-angle end, intermediate magnification position, and telephoto end

[0103]

[0104]

[0105] Table 4 Focal length values ​​of a zoom lens in a specific embodiment at the wide-angle end, intermediate magnification position, and telephoto end

[0106] Focal length / mm Wide-angle end 5.0 Intermediate magnification 14.5 Telephoto end 25.0

[0107] In this embodiment, please refer to Figures 1 to 3 , which is a schematic diagram of the structure of the zoom lens when it is at the wide-angle end, the intermediate magnification, and the telephoto end respectively; wherein the intermediate magnification can be understood as a schematic diagram of the position of each lens group in the zoom lens when the zoom lens is between the wide-angle end and the telephoto end.

[0108] Figures 4 and 5 The diagrams respectively show the longitudinal aberration and field curvature / distortion of the zoom lens at the wide-angle end. In the diagrams, S and T represent the aberration corresponding to the sagittal image plane and the meridional image plane, respectively.

[0109] Please refer to Figures 6 and 7 , are the aberration diagrams, field curvature diagrams / distortion diagrams when the zoom lens is at an intermediate magnification. S and T in the diagrams are the aberrations corresponding to the sagittal image plane and the meridional image plane, respectively.

[0110] Please refer to Figures 8 and 9 , are the spherical aberration diagram and field curvature diagram / distortion diagram when the zoom lens is at the telephoto end, where S and T are the aberrations corresponding to the sagittal image plane and the meridional image plane, respectively.

[0111] As can be seen from the above figures, the zoom lens in this embodiment can achieve good correction of spherical aberration, field curvature and distortion at intermediate magnifications, wide-angle end and telephoto end respectively.

[0112] As can be seen from the above figures, the zoom lens in this embodiment can achieve good correction of spherical aberration, field curvature and distortion at intermediate magnifications, wide-angle end and telephoto end respectively.

[0113] In addition, the present invention also provides an imaging device, which includes the zoom lens described in the above technical solution. Since the imaging device includes the zoom lens, the specific structure of the zoom lens refers to the above embodiment. Since the zoom lens of this imaging 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.

[0114] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's description and drawings, or direct / indirect applications in other related technical fields, within the scope of the present invention 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 that are oppositely arranged along the optical axis direction. The zoom lens includes a lens barrel and a plurality of lens groups disposed within the lens barrel. The plurality of lens groups includes: A first lens group fixedly disposed within the lens barrel. The first lens group includes a first lens and a second lens sequentially arranged from the object side to the image side. A second lens group movably disposed along the extension direction of the optical axis to cause the zoom lens to zoom from the wide-angle end to the telephoto end when moving toward the image side. The second lens group includes a third lens, a fourth lens, and a fifth lens sequentially arranged from the object side to the image side. A third lens group fixedly disposed within the lens barrel. The third lens group includes a sixth lens; and, A fourth lens group movably disposed along the extension direction of the optical axis to cause the zoom lens to focus when moving along the optical axis direction. The fourth lens group includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens sequentially arranged from the object side to the image side. Among them, the fourth lens, the fifth lens, the sixth lens, the eighth lens, the ninth lens, and the thirteenth lens are configured as plastic aspherical lenses. The optical power of the first lens group is positive, the optical power of the second lens group is negative, the optical power of the third lens group is positive, and the optical power of the fourth lens group is positive. The first lens has a negative optical power, and the second lens has a positive optical power. The third lens has a negative optical power, the fourth lens has a positive optical power, and the fifth lens has a negative optical power. The optical power of the sixth lens is positive. The seventh lens has a positive optical power, the eighth lens has a positive optical power, the ninth lens has a negative optical power, the tenth lens has a positive optical power, the eleventh lens has a positive optical power, the twelfth lens has a negative optical power, and the thirteenth lens has a negative optical power.

2. The zoom lens according to claim 1, wherein: The focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, and the focal length of the fourth lens group is f4. The zoom lens satisfies the following conditions: 0.098 < fw / f1 < 0.147, and -0.769 < fw / f2 < -0.513, and 0.114 < fw / f3 < 0.171, and 0.363 < fw / f4 < 0.

545.

3. The zoom lens according to claim 2, wherein: The first lens and the second lens are adhesively connected. The focal length of the first lens is f11, and the focal length of the second lens is f12. Each lens within the first lens group satisfies the following conditions: -0.939 < f1 / f11 < -0.626, and 1.496 < f1 / f12 < 2.

243.

4. The zoom lens according to claim 2, wherein: The focal length of the third lens is f21, the focal length of the fourth lens is f22, and the focal length of the fifth lens is f23. Each lens within the second lens group satisfies the following conditions: 0.779 < f2 / f21 < 1.168, and -0.479 < f2 / f22 < -0.319, and 0.336 < f2 / f23 < 0.

504.

5. The zoom lens according to claim 2, wherein: The focal length of the seventh lens is f41, the focal length of the eighth lens is f42, the focal length of the ninth lens is f43, the focal length of the tenth lens is f44, the focal length of the eleventh lens is f45, the focal length of the twelfth lens is f46, and the focal length of the thirteenth lens is f47. Each lens in the fourth lens group satisfies the following conditions: 0.649 < f4 / f41 < 0.973, and 0.61 < f4 / f42 < 0.915, and -1.31 < f4 / f43 < -0.873, and 0.699 < f4 / f44 < 1.049, and 1.139 < f4 / f45 < 1.709, and -2.251 < f4 / f46 < -1.501, and -0.246 < f4 / f47 < -0.

164.

6. The zoom lens according to claim 2, wherein: The first lens, the second lens, the third lens, the seventh lens, the tenth lens, the eleventh lens, and the twelfth lens are all glass spherical lenses.

7. The zoom lens according to claim 1, wherein: The zoom lens meets the following conditions: in, is the effective clear aperture of the first lens, and TTL is the total optical length of the zoom lens.

8. The zoom lens according to claim 1, wherein: The zoom lens satisfies the following conditions: 0.233<ΔZ W-T / TTL<0.303; Where ΔZ W-T is the relative displacement of the second lens group when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

9. An imaging device, characterized in that: A zoom lens according to any one of claims 1 to 8.

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