Zoom optical system and imaging device

Abstract

The invention provides a zoom optical system and an imaging device, and relates to the technical field of optics, the zoom optical system comprises a first lens group with negative focal power, a second lens group with positive focal power, a third lens group with negative focal power, a fourth lens group with positive focal power, an optical filter and an image plane which are sequentially arranged from an object side to an image side, wherein the second lens group and the fourth lens group are movably arranged along the extension direction of the optical axis so as to zoom the zoom optical system, and the third lens group cooperatively moves along the direction of the optical axis so as to focus the zoom optical system. A four-component structure is adopted, seventeen lenses are used, and the focal power and shape matching relation of the four lens sets and the seventeen lenses are reasonably set, so that the 8K zoom optical system which is small in size, large in target surface, small in distortion, short in focusing object distance and confocal at high and low temperatures is achieved.

Description

Technical Field

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

[0002] A zoom optical lens is a camera lens that can change its focal length within a certain range, thereby producing varying fields of view, image sizes, and subject matter. In the field of video capture, zoom lenses have gained widespread market adoption due to their flexibility and consistent imaging.

[0003] At present, the mainstream video zoom optical lenses on the market have disadvantages such as low clarity, large size, and unclear focusing at close object distances. In addition, the target area of ​​the mainstream photosensitive chips on the market is relatively small, which is increasingly unable to meet market demand. The demand for photosensitive chips with a 4 / 3" target area is gradually increasing, but the number of zoom optical systems on the market that can match this photosensitive chip is limited and cannot meet market demand. Summary of the Invention

[0004] The main purpose of the present invention is to propose a zoom optical system and an imaging device, aiming to provide an 8K zoom optical system with a small size, a large target surface, small distortion, a close focus object distance, and high and low temperature confocality.

[0005] To achieve the above objectives, the present invention provides a zoom optical system, the zoom optical system having an object side and an image side disposed opposite to each other along an optical axis, the zoom optical system comprising, arranged in order from the object side to the image side, a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with negative optical power, a fourth lens group with positive optical power, a filter, and an image plane, wherein the second lens group and the fourth lens group are movably disposed along an extension direction of the optical axis to zoom the zoom optical system, and the third lens group moves in conjunction with the optical axis to focus the zoom optical system;

[0006] The first lens group includes, arranged in order from the object side to the image side, a first lens with negative optical power, a second lens with negative optical power, a third lens with negative optical power, a fourth lens with positive optical power, and a fifth lens with negative optical power;

[0007] The second lens group includes, arranged in order from the object side to the image side, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens with negative optical power, a ninth lens with negative optical power, and a tenth lens with positive optical power;

[0008] The third lens group includes an eleventh lens with positive optical power, a twelfth lens with positive optical power, and a thirteenth lens with negative optical power, which are arranged in sequence from the object side to the image side;

[0009] The fourth lens group includes a fourteenth lens with a positive optical power, a fifteenth lens with a positive optical power, a sixteenth lens with a negative optical power, and a seventeenth lens with a positive optical power, which are arranged in sequence from the object side to the image side.

[0010] In one embodiment, the zoom optical system further includes an aperture stop, which is disposed between the first lens group and the second lens group and can move synchronously with the second lens group;

[0011] The distance from the aperture stop to the image plane is L, and the overall optical length of the zoom optical system is TTL, where 0.49 < L / TTL < 0.797.

[0012] In one embodiment, the third lens and the fourth lens are adhesively connected, the seventh lens and the eighth lens are adhesively connected, the ninth lens and the tenth lens are adhesively connected, the twelfth lens and the thirteenth lens are adhesively connected, and the fifteenth lens, the sixteenth lens and the seventeenth lens are adhesively connected.

[0013] In one embodiment, the fifth lens, the sixth lens, the eleventh lens and the thirteenth lens are all aspherical lenses.

[0014] In one embodiment, the aperture of the first lens is D, and the overall optical length of the zoom optical system is TTL, where 0.299 < D / TTL < 0.388.

[0015] In one embodiment, the zoom optical system satisfies the following conditions:

[0016] 0.272 < S1 / TTL < 0.353, 0.062 < S3 / TTL < 0.081, 0.047 < S2 / TTL < 0.061; where,

[0017] S1 is the relative displacement of the second lens group when the zoom optical system is in the wide-angle end position and when the zoom optical system is in the telephoto end position, S2 is the relative displacement of the fourth lens group when the zoom optical system is in the wide-angle end position and when the zoom optical system is in the telephoto end position, S3 is the relative displacement of the third lens group when the zoom optical system is in the wide-angle end position and when the zoom optical system is in the telephoto end position, and TTL is the overall optical length of the zoom optical system.

[0018] In one embodiment, 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, the focal length of the first lens is f11, the focal length of the second lens is f12, the focal length of the third lens is f13, the focal length of the fourth lens is f14, the focal length of the fifth lens is f15, the focal length of the sixth lens is f21, the focal length of the seventh lens is f22, the focal length of the eighth lens is f23, the focal length of the ninth lens is f24, the focal length of the tenth lens is f25, the focal length of the eleventh lens is f31, the focal length of the twelfth lens is f32, the focal length of the thirteenth lens is f33, the focal length of the fourteenth lens is f41, the focal length of the fifteenth lens is f42, the focal length of the sixteenth lens is f43, and the focal length of the seventeenth lens is f44; wherein,

[0019] 0.594≤f1 / f11≤0.804, 0.230≤f1 / f12≤0.311, 0.379≤f1 / f13≤0.513, -1.029≤f1 / f14≤-0.760, 0.399≤f1 / f15≤0.540, 0.740≤f2 / f21≤1.002, 0.740≤f2 / f22≤1.002, 0.823≤f2 / f23≤1.113, -1.385≤f2 / f24≤- 1.023, -1.251≤f2 / f25≤-0.925, -4.074≤f3 / f31≤-3.011, -0.627≤f3 / f32≤-0.463, -1.967≤f3 / f33≤-1.454, -2.428≤f4 / f41≤-1.795, 0.182≤f4 / f42≤0.247, 0.922≤f4 / f43≤1.248, -1.902≤f4 / f44≤-1.406.

[0020] In one embodiment, 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 zoom optical system at the wide-angle end is f; wherein,

[0021] -0.571≤f / f1≤-0.422, 0.351≤f / f2≤0.475, -0.188≤f / f3≤-0.139, 0.205≤f / f4≤0.277.

[0022] The present invention further provides an imaging device, comprising the above-mentioned zoom optical system, wherein the zoom optical system has an object side and an image side arranged opposite to each other along an optical axis, and comprises, arranged in sequence from the object side to the image side, a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with negative optical power, a fourth lens group with positive optical power, a filter, and an image plane, wherein the second lens group and the fourth lens group are movably arranged along the direction extending from the optical axis to zoom the zoom optical system, and the third lens group moves in conjunction with each other along the optical axis to focus the zoom optical system.

[0023] The first lens group includes, arranged in order from the object side to the image side, a first lens with negative optical power, a second lens with negative optical power, a third lens with negative optical power, a fourth lens with positive optical power, and a fifth lens with negative optical power;

[0024] The second lens group includes, arranged in order from the object side to the image side, a sixth lens with positive optical power, a seventh lens with positive optical power, an eighth lens with positive optical power, a ninth lens with negative optical power, and a tenth lens with negative optical power;

[0025] The third lens group includes an eleventh lens with positive optical power, a twelfth lens with positive optical power, and a thirteenth lens with positive optical power, which are arranged in sequence from the object side to the image side;

[0026] The fourth lens group includes a fourteenth lens with negative optical power, a fifteenth lens with positive optical power, a sixteenth lens with positive optical power, and a seventeenth lens with negative optical power, which are arranged in sequence from the object side to the image side.

[0027] The technical solution provided by the present invention effectively collects light in a wider range by setting the first lens group with negative optical focal length, changes the propagation direction of the light beam, corrects the aberration of the off-axis field of view, and is more conducive to the imaging of the light beam on the image plane; by adopting a four-element structure, using seventeen lenses, and reasonably setting the optical focal length and shape matching relationship of each lens group and lens, an 8K zoom optical system with a small size, large target surface, small distortion, close focus object distance and high and low temperature confocality is realized. 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 1A schematic structural diagram of an embodiment of a zoom optical system provided by the present invention;

[0030] Figure 2 for Figure 1 MTF diagram of the medium zoom optical system at the wide-angle end at 110 lp / mm.

[0031] Figure 3 for Figure 1 MTF diagram of a medium zoom optical system at an intermediate magnification of 110 lp / mm.

[0032] Figure 4 for Figure 1 MTF diagram of the medium zoom optical system at the telephoto end at 110 lp / mm.

[0033] Figure 5 for Figure 1 Schematic diagram of the MTF of a medium zoom optical system at different fields of view at the wide-angle end;

[0034] Figure 6 for Figure 1 Schematic diagram of the MTF of a medium zoom optical system at different fields of view at intermediate magnifications;

[0035] Figure 7 for Figure 1 Schematic diagram of the MTF of a medium zoom optical system at different fields of view at the telephoto end;

[0036] Figure 8 for Figure 1 Schematic diagram of the defocus curve of the medium zoom optical system at the wide-angle end with a frequency band of 110lp / mm;

[0037] Figure 9 for Figure 1 Schematic diagram of the defocus curve of a medium zoom optical system at an intermediate magnification of 110 lp / mm.

[0038] Figure 10 for Figure 1 Schematic diagram of the defocus curve of a medium zoom optical system at the telephoto end at 110 lp / mm;

[0039] Figure 11 for Figure 1 Field curvature distortion diagram of a medium zoom optical system at the wide-angle end;

[0040] Figure 12 for Figure 1 Field curvature distortion diagram of a medium zoom optical system at intermediate magnifications;

[0041] Figure 13 for Figure 1 Field curvature distortion diagram of a medium zoom optical system at the telephoto end;

[0042] Figure 14 for Figure 1 Light fan diagram of a medium zoom optical system at the wide-angle end;

[0043] Figure 15 for Figure 1 Light fan diagram of a medium zoom optical system at intermediate magnifications;

[0044] Figure 16 for Figure 1 Light fan diagram of a medium zoom optical system at the telephoto end;

[0045] Figure 17 for Figure 1 Axial aberration curve of the medium zoom optical system at the wide-angle end;

[0046] Figure 18 for Figure 1 Axial aberration curve of a medium zoom optical system at intermediate magnifications;

[0047] Figure 19 for Figure 1 Axial aberration curve of a medium zoom optical system at the telephoto end;

[0048] Figure 20 for Figure 1 Vertical chromatic aberration curve of the medium zoom optical system at the wide-angle end;

[0049] Figure 21 for Figure 1 Vertical chromatic aberration curve of a medium zoom optical system at intermediate magnifications;

[0050] Figure 22 for Figure 1 Vertical chromatic aberration curve of a medium zoom optical system at the telephoto end.

[0051] Description of Figure Numbers:

[0052] 100. Zoom optical system; 1. First lens group; 11. First lens; 12. Second lens; 13. Third lens; 14. Fourth lens; 15. Fifth lens; 2. Second lens group; 21. Sixth lens; 22. Seventh lens; 23. Eighth lens; 24. Ninth lens; 25. Tenth lens; 3. Third lens group; 31. Eleventh lens; 32. Twelfth lens; 33. Thirteenth lens; 4. Fourth lens group; 41. Fourteenth lens; 42. Fifteenth lens; 43. Sixteenth lens; 44. Seventeenth lens; 5. Diaphragm; 6. Filter; 7. Image plane.

[0053] 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

[0054] 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] 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 components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0056] 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 limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is 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.

[0057] A zoom optical lens is a camera lens that can change its focal length within a certain range, thereby producing varying fields of view, image sizes, and subject matter. In the field of video capture, zoom lenses have gained widespread market adoption due to their flexibility and consistent imaging.

[0058] At present, the mainstream video zoom optical lenses on the market have disadvantages such as low clarity, large size, and unclear focusing at close object distances. In addition, the target area of ​​the mainstream photosensitive chips on the market is relatively small, which is increasingly unable to meet market demand. The demand for photosensitive chips with a 4 / 3" target area is gradually increasing, but the number of zoom optical systems on the market that can match this photosensitive chip is limited and cannot meet market demand.

[0059] The main purpose of the present invention is to propose a zoom optical system and an imaging device, aiming to provide an 8K zoom optical system with a small size, a large target surface, small distortion, a close focus object distance, and high and low temperature confocality.

[0060] See also Figure 1The present invention proposes a zoom optical system 100, which has an object side and an image side arranged opposite to each other along the optical axis. The zoom optical system 100 includes a first lens group 1 with negative optical power, a second lens group 2 with positive optical power, a third lens group 3 with negative optical power, a fourth lens group 4 with positive optical power, a filter 6 and an image plane 7, which are arranged in sequence from the object side to the image side. The second lens group 2 and the fourth lens group 4 are movably arranged along the extension direction of the optical axis to zoom the zoom optical system 100, and the third lens group 3 moves in coordination along the optical axis to focus the zoom optical system 100. The first lens group 1 includes a first lens 11 with negative optical power and a second lens 12 with negative optical power, which are arranged in sequence from the object side to the image side. , a third lens 13 with negative optical focal power, a fourth lens 14 with positive optical focal power and a fifth lens 15 with negative optical focal power; the second lens group 2 includes a sixth lens 21 with positive optical focal power, a seventh lens 22 with positive optical focal power, an eighth lens 23 with negative optical focal power, a ninth lens 24 with negative optical focal power and a tenth lens 25 with positive optical focal power, which are arranged in sequence from the object side to the image side; the third lens group 3 includes an eleventh lens 31 with positive optical focal power, a twelfth lens 32 with positive optical focal power and a thirteenth lens 33 with negative optical focal power, which are arranged in sequence from the object side to the image side; the fourth lens group 4 includes a fourteenth lens 41 with positive optical focal power, a fifteenth lens 42 with positive optical focal power, a sixteenth lens 43 with negative optical focal power and a seventeenth lens 44 with positive optical focal power, which are arranged in sequence from the object side to the image side.

[0061] The technical solution provided by the present invention effectively collects light in a wider range by setting the first lens group 1 with negative optical focal length, changes the propagation direction of the light beam, corrects the aberration of the off-axis field of view, and is more conducive to the imaging of the light beam on the image plane 7; by adopting a four-element structure, using seventeen lenses, and reasonably setting the optical focal length and shape matching relationship of each lens group and lens, an 8K zoom optical system 100 with a small size, a large target surface, small distortion, a close focus object distance and high and low temperature confocality is realized.

[0062] It should be noted that the optical filter 6 in this embodiment is provided with two filters, a first filter and a second filter. The first filter is used to filter infrared light and pass visible light, and the second filter is used to pass infrared light and visible light. The first filter and the second filter are both movable, so that one can be moved onto the optical axis and the other can be moved away from the optical axis. By providing two mutually switchable filters 6 to correspond to the two operating modes of the zoom optical system 100, the present lens can achieve 8K image quality both day and night. By properly adjusting the thickness of the first filter and the second filter, the imaging quality can be further improved.

[0063] Furthermore, the zoom optical system 100 also includes an aperture 5, which is arranged between the first lens group 1 and the second lens group 2. The aperture 5 limits the light beam aperture on the optical axis and blocks part of the light, thereby reducing the light spot, improving the image contrast, and also playing the role of expanding the target surface and improving the image quality. According to actual conditions, adjusting the light flux of the aperture 5 helps to further improve the imaging quality. The distance from the aperture 5 to the image plane 7 is L, and the total optical length of the zoom optical system 100 is TTL, wherein 0.49<L / TTL<0.797. By limiting the position of the aperture 5, the light can pass through the zoom optical system 100 more smoothly, and the influence of aberration on the imaging quality can be corrected to a greater extent.

[0064] Furthermore, to improve the image quality of the optical system, reduce light energy loss, increase image clarity, protect the scale surface, and further optimize the processing process to meet design requirements, in this embodiment, the third lens 13 is cemented to the fourth lens 14, the seventh lens 22 is cemented to the eighth lens 23, the ninth lens 24 is cemented to the tenth lens 25, the twelfth lens 32 is cemented to the thirteenth lens 33, and the fifteenth lens 42, the sixteenth lens 43, and the seventeenth lens 44 are cemented. This rational use of cemented components and the appropriate distribution of optical power effectively correct aberrations and achieve athermalization at high and low temperatures. Chromatic aberration is also effectively reduced, achieving simultaneous clarity in the visible and near-infrared imaging planes.

[0065] Furthermore, the fifth lens 15, the sixth lens 21, the eleventh lens 31, and the thirteenth lens 33 are all aspherical lenses. It should be noted that aspherical lenses are characterized by a continuously changing curvature from the center to the periphery of the lens, unlike spherical lenses, which have a constant curvature from the center to the periphery.

[0066] It should be further explained that the aspheric lenses in the zoom optical system 100 provided in the embodiment of the present invention can all be plastic aspheric lenses, and lenses other than aspheric lenses can be spherical glass lenses. Glass and plastic, as two types of materials, can compensate for each other, thereby balancing high and low temperatures and reducing the total optical length of the lens. This allows the zoom optical system 100 to have stable high and low temperature performance, improves the environmental adaptability of the zoom optical system 100, and can better correct aberrations. By properly matching the temperature coefficient of the glass-plastic hybrid material, it is possible to ensure that the lens has good resolution in high and low temperature environments and significantly reduce the weight of the lens. In addition, compared with glass lenses, plastic lenses also have significant cost advantages, which can reduce the cost of the zoom optical system 100.

[0067] In this embodiment, specifically, please refer to Figure 1, the first lens 11 is a concave-convex lens, and its object-side surface is convex; the second lens 12 is a concave-convex lens, and its object-side surface is convex; the third lens 13 is a biconcave lens; the fourth lens 14 is a biconvex lens; the fifth lens 15 is a concave-convex lens, and its object-side surface is concave; the sixth lens 21 is a biconvex lens; the seventh lens 22 is a biconvex lens; the eighth lens 23 is a biconcave lens; the ninth lens 24 is a concave-convex lens, and its object-side surface is convex; the tenth lens 25 is a biconvex lens; the eleventh lens 31 is a concave-convex lens, and its object-side surface is concave; the twelfth lens 32 is a concave-convex lens, and its object-side surface is concave; the thirteenth lens 33 is a concave-convex lens, and its object-side surface is concave; the fourteenth lens 41 is a concave-convex lens, and its object-side surface is convex; the fifteenth lens 43 is a biconvex lens; the sixteenth lens 43 is a biconcave lens; the seventeenth lens 44 is a biconvex lens.

[0068] Further, the aperture of the first lens 11 is D, and the total optical length of the zoom optical system 100 is TTL, where 0.299 < D / TTL < 0.388. It should be noted that the first lens 11 has the largest aperture among all the lenses of the zoom optical system 100. By limiting the aperture of the first lens 11, the volume of the zoom optical system 100 is limited, which is also beneficial to adjusting the optical path inside the zoom optical system 100, reducing the generation of chromatic aberration and coma inside the zoom optical system 100, increasing the imaging quality of the zoom optical system 100, and at the same time facilitating the achievement of the effect of a large aperture.

[0069] Further, the zoom optical system 100 satisfies the following conditions: 0.272 < S1 / TTL < 0.353, 0.062 < S3 / TTL < 0.081, 0.047 < S2 / TTL < 0.061; where S1 is the relative displacement of the second lens group 2 when the zoom optical system is in the wide-angle end position and when the zoom optical system 100 is in the telephoto end position, S2 is the relative displacement of the fourth lens group 4 when the zoom optical system 100 is in the wide-angle end position and when the zoom optical system 100 is in the telephoto end position, S3 is the relative displacement of the third lens group 3 when the zoom optical system 10 is in the wide-angle end position and when the zoom optical system 100 is in the telephoto end position, and TTL is the total optical length of the zoom optical system 100. By controlling the moving distances of the second lens group 2, the third lens group 3, and the fourth lens group 4, the volume of each lens group can be reduced to a large extent, and thus the volume of the zoom optical system 100 can be greatly reduced.

[0070] Furthermore, 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, the focal length of the first lens 11 is f11, the focal length of the second lens 12 is f12, the focal length of the third lens 13 is f13, the focal length of the fourth lens 14 is f14, the focal length of the fifth lens 15 is f15, the focal length of the sixth lens 21 is f21, and the focal length of the seventh lens 22 is f3. The focal length of the eighth lens 23 is f23, the focal length of the ninth lens 24 is f24, the focal length of the tenth lens 25 is f25, the focal length of the eleventh lens 31 is f31, the focal length of the twelfth lens 32 is f32, the focal length of the thirteenth lens 33 is f33, the focal length of the fourteenth lens 41 is f41, the focal length of the fifteenth lens 42 is f42, the focal length of the sixteenth lens 43 is f43, and the focal length of the seventeenth lens 44 is f44. ; Among them, 0.594≤f1 / f11≤0.804, 0.230≤f1 / f12≤0.311, 0.379≤f1 / f13≤0.513, -1.029≤f1 / f14≤-0.760, 0.399≤f1 / f15≤0.540, 0.740≤f2 / f21≤1.002, 0.740≤f2 / f22≤1.002, 0.823≤f2 / f23≤1.113, -1.385≤f2 / f24 By limiting the focal length of each lens, the optical power of each lens can be reasonably matched, so that light can pass through the zoom optical system 100 more smoothly, and the influence of aberration on imaging quality can be corrected to a greater extent.

[0071] Furthermore, 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, and the focal length of the fourth lens group 4 is f4. The focal length of the zoom optical system 100 at the wide-angle end is f; wherein, -0.571≤f / f1≤-0.422, 0.351≤f / f2≤0.475, -0.188≤f / f3≤-0.139, and 0.205≤f / f4≤0.277. By limiting the focal lengths of the various lens groups, the optical powers of the various lens groups can be rationally matched, allowing light to pass through the zoom optical system more smoothly and significantly correcting the effects of aberrations on image quality.

[0072] It is worth mentioning that the surface shape of each aspheric lens in the zoom optical system 100 described in this embodiment should satisfy the following equation:

[0073]

[0074] Where c is the curvature corresponding to the radius; y is the radial coordinate (its units are the same as the lens length); k is the conic coefficient, and A, B, C, D, E, F, G, H... represent the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order, eighteenth-order... aspheric coefficients, respectively. These parameters can be used to set the shape and dimensions of the lens's aspheric surfaces facing the object and image sides.

[0075] Among them, when k is less than -1, the corresponding surface curve of the lens is a hyperbola; when k is equal to -1, the corresponding surface curve of the lens is a parabola; when -1 is less than k and less than 0, the corresponding surface curve of the lens is an ellipse; when k is equal to 0, the corresponding surface curve of the lens is a circle; when k is greater than 0, the corresponding surface curve of the lens is an oblate circle.

[0076] It should be noted that the basic parameter table of the zoom optical system 100 in this embodiment is shown in Table 1, wherein the units of the curvature radius, thickness and focal length are all millimeters (mm).

[0077] Table 1

[0078]

[0079]

[0080]

[0081] It should be noted that the basic parameters of the zoom optical system 100 at the wide-angle end, intermediate magnification and telephoto end in this embodiment are shown in Table 2, where the units of zoom 1, zoom 2, zoom 3, zoom 4 and focal length are all in millimeters (mm).

[0082] Table 2

[0083] Wide-angle end Intermediate magnification Telephoto end Zoom 1 43.6 23.14 1.22 Zoom 2 2.2 7.66 37.27 Zoom 3 2.12 25.28 19.12 Zoom 4 13.89 5.73 4.2 focal length 12.05 24 51 Aperture value 1.66 2.76 3.81

[0084] In this embodiment, the aspheric coefficients of each aspheric lens in the zoom optical system 100 include: the quadratic surface coefficient k, the fourth-order aspheric coefficient A, the sixth-order aspheric coefficient B, the eighth-order aspheric coefficient C, the tenth-order aspheric coefficient D, the twelfth-order aspheric coefficient E, the fourteenth-order aspheric coefficient F, the sixteenth-order aspheric coefficient G, and the eighteenth-order aspheric coefficient H of the surface, as shown in Table 3 below.

[0085] Table 3

[0086]

[0087] It is worth mentioning that the relevant dimensions of the zoom optical system 100 in this embodiment are shown in Table 4, and the units of all parameters in the table are millimeters (mm).

[0088] Table 4

[0089]

[0090] In this embodiment, D / TTL = 0.338, S1 / TTL = 0.307, S2 / TTL = 0.07, S3 / TTL = 0.053, the aperture value F is between 1.66 and 3.81, and the distortion is between -30.8% and -0.38%. It can be seen that the zoom optical system in this embodiment has the characteristics of small size, large target area, and low distortion.

[0091] In this embodiment, the focal length of each lens, the focal length of the lens group, the ratio of the focal length at the wide-angle end to the focal length of each lens group, and the ratio of the focal length of each lens group to the focal length of each lens in the group are shown in Table 5 below, where all focal lengths are in millimeters.

[0092] Table 5

[0093]

[0094]

[0095] Please refer to Figures 2 to 4 , which are schematic diagrams of the MTF of zoom optical system 100 at the wide-angle, intermediate magnification, and telephoto ends of this embodiment, within the 110 lp / mm frequency band. As can be seen from the figure, the MTF at 110 lp / mm is generally greater than 0.3, essentially meeting the requirements for 8K imaging quality.

[0096] Please refer to Figures 5 to 7, is a schematic diagram of the MTF of the zoom optical system 100 in this embodiment at different fields of view at the wide-angle end, intermediate magnification, and telephoto end. It can be seen from the figure that the MTF is basically greater than 0.3 under different fields of view, which basically meets the requirements of 8K imaging quality.

[0097] Please refer to Figures 8 to 10 , which shows the defocus curves of the zoom optical system 100 at the wide-angle, intermediate magnification, and telephoto ends of this embodiment at a frequency band of 110 lp / mm. As can be seen from the figure, the lens defocus rarely exceeds 10μ at the wide-angle, intermediate magnification, and telephoto ends, essentially maintaining constant defocus at both high and low temperatures.

[0098] Please refer to Figures 11 to 13 , which is a schematic diagram of the field curvature distortion of the zoom optical system 100 of this embodiment at the wide-angle end, intermediate magnification, and telephoto end. Different colors represent different wavelengths. The right curve of the same color represents the meridional direction, and the left curve represents the sagittal field curvature. The figure shows that the sagittal field curvature of this lens at the wide-angle end is no greater than 50μm, indicating that this lens can effectively correct chromatic aberration at the wide-angle end. The other curve in the figure is the system distortion curve. Distortion does not affect the system's clarity, but it will cause image distortion. The optical distortion of this system at the telephoto end is less than 0.4%.

[0099] Please refer to Figure 14-16 , are the light fan diagrams of the zoom optical system 100 in this embodiment at the wide-angle end, intermediate magnification, and telephoto end, respectively. In the figure, the horizontal axis is the normalized light beam aperture, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and at this time, all light rays in the field of view are focused on the same point on the image plane 5; the vertical axis in the image can also be expressed as the maximum diffusion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. As can be seen from the figure, the zoom optical system 100 is relatively close to the horizontal axis at each wavelength in each field of view, indicating that the vertical axis aberration of each wavelength is well corrected. In addition, there is no obvious dispersion in the curves of each color, indicating that the zoom optical system 100 also has good correction for chromatic aberration, ensuring that the zoom optical system 100 meets the imaging requirements of clear imaging in the entire band.

[0100] Please refer to Figure 17-Figure 19, are axial aberration curves of the zoom optical system 100 at the wide-angle end, intermediate magnification, and telephoto end of this embodiment. The vertical direction represents the normalized aperture, with 0 representing the optical axis and the vertex in the vertical axis representing the maximum pupil radius; the horizontal direction represents the offset relative to the main wavelength, in millimeters (mm). As can be seen from the figure, when the zoom optical system 100 is at the wide-angle end, the axial aberrations of different wavelengths are basically controlled within the range of (-0.04mm, +0.004mm); when the zoom optical system 100 is at the intermediate magnification, the axial aberrations of different wavelengths are basically controlled within the range of (-0.02mm, +0.05mm); when the zoom optical system 100 is at the telephoto end, the axial aberrations of different wavelengths are basically controlled within the range of (-0.06mm, +0.09mm), indicating that the axial aberrations of the zoom optical system 100 at the wide-angle end, intermediate magnification, and telephoto end are all well controlled, and can meet the requirements of wide-spectrum applications across the entire wavelength band.

[0101] Please refer to Figure 20-22 , are graphs of vertical chromatic aberration of the zoom optical system 100 at the wide-angle end, intermediate magnifications, and telephoto ends, respectively. As can be seen from the graph, when the zoom optical system 100 is at the wide-angle end, the vertical chromatic aberration at different wavelengths is controlled within the range of (-2μm, +9μm); when the zoom optical system 100 is at the intermediate magnifications, the vertical chromatic aberration at different wavelengths is controlled within the range of (-1μm, +5μm); and when the zoom optical system 100 is at the telephoto end, the vertical chromatic aberration at different wavelengths is controlled within the range of (-6μm, +1μm). This demonstrates that the vertical chromatic aberration of the zoom optical system 100 at the wide-angle end, intermediate magnifications, and telephoto ends is well controlled, meeting the requirements of full-band, wide-spectrum applications.

[0102] The present invention also proposes an imaging device, which includes the above-mentioned zoom optical system 100. Since the imaging device includes the zoom optical system 100, the specific structure of the zoom optical system 100 refers to the above-mentioned embodiment. Since the zoom optical system 100 of this imaging device adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0103] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by utilizing the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A zoom optical system, characterized in that: The zoom optical system has an object side and an image side that are relatively arranged along the optical axis direction. The zoom optical system includes a first lens group with a negative optical power, a second lens group with a positive optical power, a third lens group with a negative optical power, a fourth lens group with a positive optical power, a filter, and an image plane arranged in sequence from the object side to the image side. Among them, the second lens group and the fourth lens group are movably arranged along the extension direction of the optical axis to zoom the zoom optical system, and the third lens group moves cooperatively along the optical axis direction to focus the zoom optical system; The first lens group includes a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a negative optical power, a fourth lens with a positive optical power, and a fifth lens with a negative optical power arranged in sequence from the object side to the image side; The second lens group includes a sixth lens with a positive optical power, a seventh lens with a positive optical power, an eighth lens with a negative optical power, a ninth lens with a negative optical power, and a tenth lens with a positive optical power arranged in sequence from the object side to the image side; The third lens group includes an eleventh lens with a positive optical power, a twelfth lens with a positive optical power, and a thirteenth lens with a negative optical power arranged in sequence from the object side to the image side; The fourth lens group includes a fourteenth lens with a positive optical power, a fifteenth lens with a positive optical power, a sixteenth lens with a negative optical power, and a seventeenth lens with a positive optical power arranged in sequence from the object side to the image side.

2. The zoom optical system according to claim 1, wherein: The zoom optical system further includes an aperture stop, which is disposed between the first lens group and the second lens group and can move synchronously with the second lens group; The distance from the aperture stop to the image plane is L, and the overall optical length of the zoom optical system is TTL, where 0.49 < L / TTL < 0.

797.

3. The zoom optical system according to claim 1, wherein: The third lens and the fourth lens are adhesively connected, the seventh lens and the eighth lens are adhesively connected, the ninth lens and the tenth lens are adhesively connected, the twelfth lens and the thirteenth lens are adhesively connected, and the fifteenth lens, the sixteenth lens, and the seventeenth lens are adhesively connected.

4. The zoom optical system according to claim 1, wherein: The fifth lens, the sixth lens, the eleventh lens, and the thirteenth lens are all aspherical lenses.

5. The zoom optical system according to claim 1, wherein: The aperture of the first lens is D, and the overall optical length of the zoom optical system is TTL, where 0.299 < D / TTL < 0.

388.

6. The zoom optical system according to claim 1, wherein: The zoom optical system satisfies the following conditions: 0.272 < S1 / TTL < 0.353, 0.062 < S3 / TTL < 0.081, 0.047 < S2 / TTL < 0.061; where, S1 is the relative displacement of the second lens group when the zoom optical system is in the wide-angle end position and when the zoom optical system is in the telephoto end position, S2 is the relative displacement of the fourth lens group when the zoom optical system is in the wide-angle end position and when the zoom optical system is in the telephoto end position, S3 is the relative displacement of the third lens group when the zoom optical system is in the wide-angle end position and when the zoom optical system is in the telephoto end position, and TTL is the overall optical length of the zoom optical system.

7. The zoom optical system according to claim 1, wherein: 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, the focal length of the first lens is f11, the focal length of the second lens is f12, the focal length of the third lens is f13, the focal length of the fourth lens is f14, the focal length of the fifth lens is f15, the focal length of the sixth lens is f21, the focal length of the seventh lens is f22, the focal length of the eighth lens is f23, the focal length of the ninth lens is f24, the focal length of the tenth lens is f25, the focal length of the eleventh lens is f31, the focal length of the twelfth lens is f32, the focal length of the thirteenth lens is f33, the focal length of the fourteenth lens is f41, the focal length of the fifteenth lens is f42, the focal length of the sixteenth lens is f43, and the focal length of the seventeenth lens is f44; wherein, 0.594≤f1 / f11≤0.804, 0.230≤f1 / f12≤0.311, 0.379≤f1 / f13≤0.513, -1.029≤f1 / f14≤-0.760, 0.399≤f1 / f15≤0.540, 0.740≤f2 / f21≤1.002, 0.740≤f2 / f22≤1.002, 0.823≤f2 / f23≤1.113, -1.385≤f2 / f24≤- 1.023, -1.251≤f2 / f25≤-0.925, -4.074≤f3 / f31≤-3.011, -0.627≤f3 / f32≤-0.463, -1.967≤f3 / f33≤-1.454, -2.428≤f4 / f41≤-1.795, 0.182≤f4 / f42≤0.247, 0.922≤f4 / f43≤1.248, -1.902≤f4 / f44≤-1.

406.

8. The zoom optical system according to claim 1, wherein: 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 zoom optical system at the wide-angle end is f; wherein, -0.571≤f / f1≤-0.422, 0.351≤f / f2≤0.475, -0.188≤f / f3≤-0.139, 0.205≤f / f4≤0.

277.

9. An imaging device, characterized in that: The invention comprises a zoom optical system as claimed in any one of claims 1 to 8.

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