Zoom lens and imaging device

Abstract

The present invention discloses a zoom lens and an imaging device, wherein an optical axis is formed in the zoom lens, the zoom lens has an object side and an image side arranged opposite to each other in the extension direction of the optical axis, the zoom lens comprises a lens barrel and a lens assembly; the lens assembly comprises a first lens group with positive optical focal length, a second lens group with negative optical focal length, a third lens group with positive optical focal length, a fourth lens group with positive optical focal length, and a fifth lens group, which are arranged in sequence from the object side to the image side; the first lens group, the third lens group, and the fifth lens group are all fixedly mounted on the lens barrel, and the second lens group and the fourth lens group are both movably mounted on the lens barrel along the optical axis direction; the present invention aims to solve the problem of high manufacturing cost of existing zoom lenses.

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. 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 solve the problem of high manufacturing cost of existing zoom lenses.

[0004] To achieve the above objectives, the present invention provides a zoom lens having an optical axis formed therein, the zoom lens having an object side and an image side oppositely disposed in an extending direction of the optical axis, and comprising:

[0005] lens barrel; and,

[0006] a lens assembly comprising a first lens group with positive optical power, a second lens group with negative optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, and a fifth lens group arranged in sequence from the object side to the image side, wherein the first lens group, the third lens group, and the fifth lens group are all fixedly mounted on the lens barrel, and the second lens group and the fourth lens group are both movably mounted on the lens barrel along the optical axis;

[0007] When the zoom lens is at the wide-angle end, the following conditions are met: 0.11 <fw / f1<0.17,-0.77<fw / f2<-0.51,0.14<fw / f3<0.21,0.26<fw / f4<0.39,-0.1<fw / f5<0.1;

[0008] 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 focal length of the fifth lens group is f5.

[0009] Optionally, the first lens group includes a first lens with negative optical power, a second lens with positive optical power, and a third lens with positive optical power, which are arranged in sequence from the object side to the image side, and the first lens group meets the following conditions: -0.90 <f1 / f11<-0.60,0.74<f1 / f12<1.11,0.70<f1 / f13<1.05;

[0010] Among them, the focal length of the first lens is f11, the focal length of the second lens is f12, and the focal length of the third lens is f13.

[0011] Optionally, the effective clear aperture of the first lens is L11, and the overall optical length of the zoom lens is TTL. Inside the zoom lens: 0.320 < L11 / TTL < 0.391.

[0012] Optionally, the second lens group includes a fourth lens with a negative optical power, a fifth lens with a negative optical power, and a sixth lens with a positive optical power, which are arranged in sequence from the object side to the image side. The fourth lens is a glass spherical lens, and the fifth lens and the sixth lens are both plastic aspherical lenses. The second lens group satisfies the following conditions: 0.78 < f2 / f21 < 1.17, 0.47 < f2 / f22 < 0.70, and -0.61 < f2 / f23 < -0.41;

[0013] Among them, the focal length of the fourth lens is f21, the focal length of the fifth lens is f22, and the focal length of the sixth lens is f23.

[0014] Optionally, the relative displacement amount of the fourth lens when the zoom lens is in the wide-angle end position and when the zoom lens is in the telephoto end position is ΔZ W-T , and the overall optical length of the zoom lens is TTL. Inside the zoom lens: 0.306 < ΔZ W-T / TTL < 0.398.

[0015] Optionally, the third lens group includes a seventh lens with a positive optical power, an eighth lens with a positive optical power, and a ninth lens with a negative optical power, which are arranged at intervals in sequence from the object side to the image side. The seventh lens is a glass spherical lens, and the eighth lens and the ninth lens are both plastic aspherical lenses. The third lens group satisfies the following conditions: 1.27 < f3 / f31 < 1.90, 1.08 < f3 / f32 < 1.63, -2.79 < f3 / f33 < -1.86;

[0016] Among them, the focal length of the seventh lens is f31, the focal length of the eighth lens is f32, and the focal length of the ninth lens is f33.

[0017] Optionally, the eighth lens satisfies the following conditions: 1.5 < Nd32 < 1.7, and 15 < Vd32 < 30;

[0018] Among them, the refractive index of the d light (588 nm) of the eighth lens is Nd32, and the Abbe number of the eighth lens is Vd32.

[0019] Optionally, the fourth lens group includes a tenth lens with positive focal power, an eleventh lens with negative focal power, and a twelfth lens with positive focal power, which are sequentially arranged from the object side to the image side, the tenth lens is a glass spherical lens, the eleventh lens and the twelfth lens are both plastic aspherical lenses, and the third lens group meets the following conditions: 0.41 <f4 / f41<0.61,-1.13<f4 / f42<-0.75,1.19<f4 / f43<1.79;

[0020] The focal length of the tenth lens is f41, the focal length of the eleventh lens is f42, and the focal length of the twelfth lens is f43.

[0021] Optionally, the fifth lens group includes a thirteenth lens, and the thirteenth lens is a plastic aspheric lens.

[0022] In addition, the present invention further provides an imaging device, comprising the above-mentioned zoom lens; wherein an optical axis is formed in the zoom lens, the zoom lens has an object side and an image side arranged opposite to each other in the direction in which the optical axis extends, and the zoom lens comprises:

[0023] lens barrel; and,

[0024] a lens assembly comprising a first lens group with positive optical power, a second lens group with negative optical power, a third lens group with positive optical power, a fourth lens group with positive optical power, and a fifth lens group arranged in sequence from the object side to the image side, wherein the first lens group, the third lens group, and the fifth lens group are all fixedly mounted on the lens barrel, and the second lens group and the fourth lens group are both movably mounted on the lens barrel along the optical axis;

[0025] When the zoom lens is at the wide-angle end, the following conditions are met: 0.11 <fw / f1<0.17,-0.77<fw / f2<-0.51,0.14<fw / f3<0.21,0.26<fw / f4<0.39,-0.1<fw / f5<0.1;

[0026] 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 focal length of the fifth lens group is f5.

[0027] In the technical solution provided by the present invention, the first lens group, the third lens group and the fifth lens group are fixedly mounted on the lens barrel, and the second lens group and the fourth lens group are movably mounted on the lens barrel along the optical axis direction, wherein, under the action of an external force, the second lens group moves toward the image side so that the zoom lens zooms from the wide-angle end to the telephoto end, and at the same time, the fourth lens group moves along the optical axis direction so that the zoom lens focuses, so that the zoom lens keeps the image on the imaging surface clear during the zooming process, and the first lens group has positive focal power, the second lens group has negative focal power, the third lens group has positive focal power, the fourth lens group has positive focal power, and the fifth lens group has positive focal power. Through the reasonable arrangement of the five lens groups and the focal length of the zoom lens at the wide-angle end, the conditional restriction of the focal length ratio of each lens group and the use of plastic aspheric surfaces, the technical problem that the existing zoom lens cannot have the coexistence of low cost, small aperture, wide angle, small distortion and large magnification can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 A schematic structural diagram of the zoom lens provided by the present invention when it is at the wide-angle end;

[0030] Figure 2 for Figure 1 Schematic diagram of the structure of the zoom lens when it is at an intermediate magnification;

[0031] Figure 3 for Figure 1 Schematic diagram of the structure of the zoom lens when it is at the telephoto end;

[0032] Figure 4 for Figure 1 Spherical aberration diagram of the zoom lens at the wide-angle end;

[0033] Figure 5 for Figure 1 Field curvature diagram when the zoom lens is at the wide-angle end;

[0034] Figure 6 for Figure 1 Distortion diagram of the zoom lens at the wide-angle end;

[0035] Figure 7 for Figure 1Spherical aberration diagram of the zoom lens at intermediate magnifications;

[0036] Figure 8 for Figure 1 Field curvature diagram when the zoom lens is at intermediate magnification;

[0037] Figure 9 for Figure 1 Distortion diagram of the zoom lens at intermediate magnifications;

[0038] Figure 10 for Figure 1 Spherical aberration diagram of the zoom lens at the telephoto end;

[0039] Figure 11 for Figure 1 Field curvature diagram when the zoom lens is at the telephoto end;

[0040] Figure 12 for Figure 1 Distortion diagram of the zoom lens at the telephoto end.

[0041] Description of Figure Numbers:

[0042]

[0043]

[0044] 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

[0045] 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.

[0046] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0047] 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 suggesting 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. 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.

[0048] 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.

[0049] In view of this, the present invention provides a zoom lens, Figures 1 to 12 In one embodiment of a zoom lens provided by the present invention, all aspherical lens elements are plastic lenses, resulting in a low manufacturing cost. This solves the high manufacturing cost issue of existing zoom lenses and can be widely used in imaging devices such as surveillance cameras and video cameras. The zoom lens will be described below with reference to the accompanying figures.

[0050] See also Figure 1 、 Figure 2 and Figure 3 The present invention proposes a zoom lens 100, wherein an optical axis is formed in the zoom lens 100, and the zoom lens 100 has an object side and an image side arranged opposite to each other in the extension direction of the optical axis. The zoom lens 100 includes a lens barrel and a lens assembly; the lens assembly includes a first lens group 1 with positive optical power, a second lens group 2 with negative optical power, a third lens group 3 with positive optical power, a fourth lens group 4 with positive optical power, and a fifth lens group 5 with positive optical power, which are arranged in sequence from the object side to the image side, the first lens group 1, the third lens group 3, and the fifth lens group 5 are all fixedly mounted on the lens barrel, and the second lens group 2 and the fourth lens group 4 are both movably mounted on the lens barrel along the optical axis.

[0051] In the technical solution provided by the present invention, the first lens group 1, the third lens group 3, and the fifth lens group 5 are fixedly installed on the lens barrel, and the second lens group 2 and the fourth lens group 4 are movably installed on the lens barrel along the optical axis direction. Among them, under the action of an external force, the second lens group 2 moves toward the image side to make the zoom lens 100 zoom from the wide-angle end to the telephoto end. At the same time, the fourth lens group 4 moves along the optical axis direction to make the zoom lens 100 focus, so that the imaging surface of the zoom lens 100 remains clear during the zooming process. And the first lens group 1 has a positive optical power, the second lens group 2 has a negative optical power, the third lens group 3 has a positive optical power, the fourth lens group 4 has a positive optical power, and the fifth lens group 5 can be positive or negative in optical power. Through the reasonable setting of the five lens groups, the focal length of the wide-angle end of the zoom lens 100, the conditional limitation of the focal length ratio of each lens group, and the use of plastic aspherical surfaces, the technical problem that the existing zoom lens 100 cannot have the coexistence of low cost, small aperture, wide angle, small distortion and large magnification is solved.

[0052] In the zoom lens 100, the following conditions are satisfied: 0.11 < fw / f1 < 0.17, -0.77 < fw / f2 < -0.51, 0.14 < fw / f3 < 0.21, 0.26 < fw / f4 < 0.39, -0.1 < fw / f5 < 0.1; where the focal length of the zoom lens 100 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 focal length of the fifth lens group 5 is f5. Specifically, in this embodiment, the ratios of the focal length of the zoom lens 100 at the wide-angle end to the focal lengths of each lens group are as follows: fw / f1 = 0.13; fw / f2 = -0.62; fw / f3 = 0.17; fw / f4 = 0.31; fw / f5 = 0.003. By reasonably distributing the optical power of the entire lens, the chromatic aberration between the lenses is mutually compensated. When the entrance pupil diameter increases, it can also ensure high color reproducibility, and a good imaging effect can be obtained even in a weakly lit environment.

[0053] It should be noted that both the second lens group 2 and the fourth lens group 4 can be driven by an external force to move along the optical axis direction. Among them, the external force drive can be a drive motor drive or manual adjustment by a human, and no limitation is made here.

[0054] Please continue to refer to Figure 1 、 Figure 2 和 Figure 3, the first lens group 1 includes a first lens 11 with a negative focal power, a second lens 12 with a positive focal power, and a third lens 13 with a positive focal power, which are arranged in sequence from the object side to the image side. The first lens 11, the second lens 12, and the third lens 13 are glass spherical lenses. The first lens group 1 satisfies the following conditions: -0.90 < f1 / f11 < -0.60, 0.74 < f1 / f12 < 1.11, 0.70 < f1 / f13 < 1.05; where, the focal length of the first lens group is f1, the focal length of the first lens 11 is f11, the focal length of the second lens 12 is f12, and the focal length of the third lens 13 is f13; specifically, in the embodiment, the focal length of the first lens group 1 is 42.3, the focal length of the first lens 11 is -58.7, the focal length of the second lens 12 is 47.4, the focal length of the third lens 13 is 50.3, f1 / f11 = -0.72, f1 / f12 = 0.89, f1 / f13 = 0.84. The first lens 11, the second lens 12, and the third lens 13 are all glass spherical lenses. Using glass spherical lenses can ensure the resolution ability of the zoom lens 100.

[0055] Further, in this embodiment, the first lens 11 and the second lens 12 are glued together to form a first glued lens with a positive focal power; thus, the glued part is reasonably used to enable the optical components to improve the image quality of the optical system, reduce the loss of light energy, increase the imaging clarity, protect the scale surface, and further optimize the processing flow to meet the design requirements.

[0056] Further, the effective clear aperture of the first lens 11 is L11, and the overall optical length of the zoom lens 100 is TTL. In the zoom lens 100: 0.320 < L11 / TTL < 0.391. Specifically, in this embodiment, the effective clear aperture of the first lens 11 is 29.0 mm, the overall optical length of the zoom lens 100 is 81.6 mm, and in the zoom lens 100: L11 / TTL = 0.36.

[0057] Specifically, the second lens group 2 includes a fourth lens 21 with a negative optical power, a fifth lens 22 with a negative optical power, and a sixth lens 23 with a positive optical power, which are arranged in sequence from the object side to the image side. The second lens group 2 satisfies the following conditions: 0.78 < f2 / f21 < 1.17, 0.47 < f2 / f22 < 0.70, and -0.61 < f2 / f23 < -0.41; where the focal length of the second lens group is f2, the focal length of the fourth lens 21 is f21, the focal length of the fifth lens 22 is f22, and the focal length of the sixth lens 23 is f23. Specifically, in this embodiment, the focal length of the second lens group 2 is -9.1, the focal length of the fourth lens 21 is -9.7, the focal length of the fifth lens 22 is -16.3, the focal length of the sixth lens 23 is 18.8, f2 / f21 = 0.94, f2 / f22 = 0.56, f2 / f23 = -0.49; the fourth lens 21 is a glass spherical lens, and the fifth lens 22 and the sixth lens 23 are both plastic aspherical lenses. The combination of the two realizes low cost and improves the resolution of the lens.

[0058] Further, the relative displacement amount of the fourth lens 21 when the zoom lens 100 is in the wide-angle end position and when the zoom lens 100 is in the telephoto end position is ΔZ W-T , and the optical total length of the zoom lens 100 is TTL. In the zoom lens 100: 0.306 < ΔZ W-T / TTL < 0.398. Specifically, in this embodiment, the relative displacement amount of the fourth lens 21 when the zoom lens 100 is in the wide-angle end position and when the zoom lens 100 is in the telephoto end position is 28.7 mm, the optical total length of the zoom lens 100 is 81.6 mm, and in the zoom lens 100: ΔZ W-T / TTL = 0.35.

[0059] Please continue to refer to Figures 1 to 3, the third lens group 3 includes a seventh lens 31 with a positive focal power, an eighth lens 32 with a positive focal power, and a ninth lens 33 with a negative focal power, which are sequentially arranged at intervals from the object side to the image side. The seventh lens 31 is a glass spherical lens, and the eighth lens 32 and the ninth lens 33 are both plastic aspherical lenses. The third lens group 3 satisfies the following conditions: 1.27 < f3 / f31 < 1.90, 1.08 < f3 / f32 < 1.63, -2.79 < f3 / f33 < -1.86; where the focal length of the third lens group is f3, the focal length of the seventh lens 31 is f31, the focal length of the eighth lens 32 is f32, and the focal length of the ninth lens 33 is f33. Specifically, in this embodiment, the focal length of the third lens group 3 is 33.73, the focal length of the seventh lens 31 is 22.19, the focal length of the eighth lens 32 is 25.92, the focal length of the ninth lens 33 is -15.10, f3 / f31 = 1.52, f3 / f32 = 1.30, f3 / f33 = -2.23.

[0060] Further, the eighth lens 33 is a small Abbe number aspherical plastic lens, and the eighth lens 33 satisfies the following conditions: 1.5 < Nd32 < 1.7, and 15 < Vd32 < 30; where the refractive index of the d light (588 nm) of the eighth lens 32 is Nd32, and the Abbe number of the eighth lens 32 is Vd32. Specifically, in this embodiment, the refractive index of the d light (588 nm) of the eighth lens 32 is 1.64, and the Abbe number of the eighth lens 32 is 22.4.

[0061] Specifically, the fourth lens group 4 includes a tenth lens 41 with a positive focal power, an eleventh lens 42 with a negative focal power, and a twelfth lens 43 with a positive focal power, which are sequentially arranged at intervals from the object side to the image side. The tenth lens 41 is a glass spherical lens, and the eleventh lens 42 and the twelfth lens 43 are both plastic aspherical lenses. The fourth lens group 4 satisfies the following conditions: 0.41 < f4 / f41 < 0.61, -1.13 < f4 / f42 < -0.75, 1.19 < f4 / f43 < 1.79; where the focal length of the fourth lens group is f4, the focal length of the tenth lens 41 is f41, the focal length of the eleventh lens 42 is f42, and the focal length of the twelfth lens 43 is f43. Specifically, in this embodiment, the focal length of the fourth lens group 4 is 18.06, the focal length of the tenth lens 41 is 37.12, the focal length of the eleventh lens 42 is -19.98, the focal length of the twelfth lens 43 is 12.62, f4 / f41 = 0.49, f4 / f42 = -0.90, f4 / f43 = 1.43.

[0062] Please continue to refer to Figures 1 to 3 In this embodiment, the fifth lens group 5 includes a thirteenth lens 51, and the thirteenth lens 51 is a plastic aspheric lens.

[0063] It can be understood that the surface of the photosensitive chip 8 facing the object side is the imaging surface.

[0064] The optical assembly further includes an aperture 6, which is located between the second lens group 2 and the third lens group 3. In this embodiment, the aperture 6 is an adjustable aperture, which can adjust the aperture accordingly as the ambient light intensity changes. This arrangement effectively shortens the total length of the lens, while rationally utilizing vignetting to achieve large aperture and high resolution.

[0065] Specifically, in this embodiment, the zoom lens 100 further includes a filter 7, which is located between the fifth lens group 5 and the imaging surface. The filter 7 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 7 can also be used to adjust the color of the object during the final imaging, thereby improving the imaging quality.

[0066] Specifically, the imaging surface can be understood as the surface of the photosensitive chip 8 facing the object side, that is, it can be the surface of a camera element such as a CCD or CMOS. More specifically, in this embodiment, the imaging surface is the surface of a CMOS solid-state imaging element (the effective imaging circle diameter of the CMOS in this embodiment is 6.7 mm). It can be understood that the light carrying the information of the object can pass through the first lens group 1, the second lens group 2, the aperture 6, the third lens group 3, the fourth lens group 4, the fifth lens group 5, and the filter 7 in sequence and finally be imaged on the imaging surface.

[0067] In this embodiment, the effective imaging circle diameter is d, the focal length at the wide-angle end is fw, the focal length at the telephoto end is ft, and the aperture number at the wide-angle end is Fno. w , the aperture number at the telephoto end is Fno T , the optical distortion is α, the total optical length of the zoom lens 100 is TTL, where: d = 6.7 mm, fw = 5.633 mm, ft = 90.2 mm, Fno w =1.67, Fno T =3.7, -6%≤α≤6%, TTL=81.6mm.

[0068] Specifically, in this embodiment, the refractive index, curvature radius, and thickness intervals of the lens material are shown in the following table:

[0069] Table 1 Lens parameters

[0070]

[0071]

[0072] Specifically, in this embodiment, the fifth lens 22, the sixth lens 23, the eighth lens 32, the ninth lens 33, the eleventh lens 42, the twelfth lens 43 and the thirteenth lens 51 are (plastic) aspherical lenses. The characteristic of aspherical lenses is that the curvature changes continuously from the center of the lens to the periphery. Unlike spherical lenses with a constant curvature from the center of the lens to the periphery, aspherical lenses have better curvature radius characteristics and have the advantages of improving distortion aberration and astigmatism. After using aspherical lenses, aberrations occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens. The use of glass lenses can reduce the impact of temperature on the optical performance of the lens.

[0073] Furthermore, in this embodiment, the aspheric surface shape of the aspheric lens satisfies the following conditions:

[0074]

[0075] 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 conic quadratic curve 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, G are high-order aspheric coefficients, and the high-order coefficients of each aspheric mirror surface can be found in Appendix Table 2.

[0076] Table 2 Conic coefficients and aspheric coefficients corresponding to aspheric lenses

[0077]

[0078]

[0079] Table 3 Zoom data of the zoom lens at wide-angle end, intermediate magnification position, and telephoto end

[0080] wide angle Intermediate magnification Telephoto T(6) 0.50 24.90 29.22 T(12) 29.70 5.30 0.98 T(19) 5.31 2.95 12.37 T(25) 10.33 12.69 3.27

[0081] In this embodiment, please refer to Figures 1 to 3 , which are schematic structural diagrams of the zoom lens 100 when it is at the wide-angle end, the intermediate magnification, and the telephoto end respectively; wherein the intermediate magnification can be understood as the state of the zoom lens 100 being between the wide-angle end and the telephoto end.

[0082] Figures 4 to 6The aberration diagram, field curvature diagram, and distortion diagram of the zoom lens 100 at the wide-angle end are shown, wherein the d-line (λ=588nm) is used. The S and T in the diagram are the aberrations corresponding to the sagittal image plane and the meridional image plane, respectively. Figures 7 to 9 , are aberration diagrams, field curvature diagrams, and distortion diagrams of the zoom lens 100 at intermediate magnifications, wherein the d-line (λ=588nm) is used. S and T in the diagram are aberrations corresponding to the sagittal image plane and the meridional image plane, respectively. Please refer to Figures 10 to 12 , which are spherical aberration diagrams, field curvature diagrams, and distortion diagrams of the zoom lens 100 at the telephoto end, wherein the d-line (λ=588nm) is used. S and T in the diagram are aberrations corresponding to the sagittal image plane and the meridional image plane, respectively.

[0083] As can be seen from the above figures, the zoom lens 100 in this embodiment can achieve good correction of spherical aberration, field curvature and distortion at intermediate magnifications, wide-angle end and telephoto end respectively.

[0084] In addition, the present invention also provides an imaging device, which includes the zoom lens 100 described in the above technical solution. Since the imaging device includes the zoom lens 100, the specific structure of the zoom lens 100 refers to the above embodiment. Since the zoom lens 100 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 described one by one here.

[0085] 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: An optical axis is formed inside the zoom lens. The zoom lens has an object side and an image side that are oppositely arranged in the extending direction of the optical axis. The zoom lens includes: a lens barrel; and, a lens assembly including a first lens group with a positive optical power, a second lens group with a negative optical power, a third lens group with a positive optical power, a fourth lens group with a positive optical power, and a fifth lens group with a positive optical power, which are arranged in sequence from the object side to the image side. The first lens group, the third lens group, and the fifth lens group are all fixedly mounted on the lens barrel, and the second lens group and the fourth lens group are both movably mounted on the lens barrel along the optical axis direction; When the zoom lens is at the wide-angle end, the following conditions are satisfied: 0.11 < fw / f1 < 0.17, -0.77 < fw / f2 < -0.51, 0.14 < fw / f3 < 0.21, 0.26 < fw / f4 < 0.39, 0.003 ≤ fw / f5 < 0.1; where, 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 focal length of the fifth lens group is f5.

2. The zoom lens according to claim 1, wherein: The first lens group includes a first lens with a negative optical power, a second lens with a positive optical power, and a third lens with a positive optical power, which are arranged in sequence from the object side to the image side. The first lens group satisfies the following conditions: -0.90 < f1 / f11 < -0.60, 0.74 < f1 / f12 < 1.11, 0.70 < f1 / f13 < 1.05; where, the focal length of the first lens is f11, the focal length of the second lens is f12, and the focal length of the third lens is f13.

3. The zoom lens according to claim 2, wherein: The effective clear aperture of the first lens is L11, and the overall optical length of the zoom lens is TTL. Inside the zoom lens: 0.320 < L11 / TTL < 0.

391.

4. The zoom lens according to claim 1, wherein: The second lens group includes a fourth lens with a negative optical power, a fifth lens with a negative optical power, and a sixth lens with a positive optical power, which are arranged in sequence from the object side to the image side. The fourth lens is a glass spherical lens, and the fifth lens and the sixth lens are both plastic aspherical lenses. The second lens group satisfies the following conditions: 0.78 < f2 / f21 < 1.17, and 0.47 < f2 / f22 < 0.70, and -0.61 < f2 / f23 < -0.41; where, the focal length of the fourth lens is f21, the focal length of the fifth lens is f22, and the focal length of the sixth lens is f23.

5. The zoom lens according to claim 4, wherein: The relative displacement of the fourth lens when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position is ΔZ W-T , the total optical length of the zoom lens is TTL, in the zoom lens: 0.306<ΔZ W-T / TTL<0.

398.

6. The zoom lens according to claim 1, wherein: The third lens group includes a seventh lens with a positive focal power, an eighth lens with a positive focal power, and a ninth lens with a negative focal power, which are sequentially arranged at intervals from the object side to the image side. The seventh lens is a glass spherical lens, and the eighth and ninth lenses are both plastic aspherical lenses. The third lens group satisfies the following conditions: 1.27 < f3 / f31 < 1.90, 1.08 < f3 / f32 < 1.63, -2.79 < f3 / f33 < -1.86; where, the focal length of the seventh lens is f31, the focal length of the eighth lens is f32, and the focal length of the ninth lens is f33.

7. The zoom lens according to claim 6, wherein: The eighth lens satisfies the following conditions: 1.5 < Nd32 < 1.7, and 15 < Vd32 < 30; where, the refractive index of the d light (588nm) of the eighth lens is Nd32, and the Abbe number of the eighth lens is Vd32.

8. The zoom lens according to claim 1, wherein: The fourth lens group includes a tenth lens with a positive focal power, an eleventh lens with a negative focal power, and a twelfth lens with a positive focal power, which are sequentially arranged at intervals from the object side to the image side. The tenth lens is a glass spherical lens, and the eleventh and twelfth lenses are both plastic aspherical lenses. The fourth lens group satisfies the following conditions: 0.41 < f4 / f41 < 0.61, -1.13 < f4 / f42 < -0.75, 1.19 < f4 / f43 < 1.79; where, the focal length of the tenth lens is f41, the focal length of the eleventh lens is f42, and the focal length of the twelfth lens is f43.

9. The zoom lens according to claim 1, wherein: The fifth lens group includes a thirteenth lens, and the thirteenth lens is a plastic aspherical lens.

10. An imaging device, characterized in that: Comprising a zoom lens according to any one of claims 1-9.

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