Zoom optical system and imaging device

Abstract

The invention provides a zoom optical system and an imaging device, and is based on the technical field of optics, and the zoom optical system is provided with an object side and an image side which are oppositely arranged in the direction of an optical axis. Comprising a first lens group with positive focal power, a second lens group with negative focal power, a third lens group with positive focal power, a fourth lens group with negative focal power, a fifth 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, the second lens group and the fifth lens group are movably arranged along the extension direction of the optical axis so as to zoom the zoom optical system, and the fourth lens group cooperatively moves along the direction of the optical axis so as to focus the zoom optical system. A five-component structure is adopted, seventeen lenses are used, and the focal power and shape matching relation of the five 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 particularly relates to a zoom optical system and an imaging device. Background Art

[0002] A zoom optical lens is a camera lens that can change the focal length within a certain range, thereby obtaining different field angles of different widths, different sizes of images, and different ranges of scenes. In the field of video shooting, zoom optical systems have been widely used due to advantages such as long shooting distance and large shooting angle.

[0003] Currently, the mainstream video zoom optical lenses on the market have problems such as low clarity, large volume, unclear focusing at close object distances, and the target surface of the mainstream photosensitive chips on the market is small, which can no longer meet the market demand. The demand for photosensitive chips with a 4 / 3″ target surface is gradually increasing, but the types of zoom optical systems that can match this photosensitive chip on the market are few and cannot meet the market demand. Summary of the Invention

[0004] The main object of the present invention is to provide a zoom optical system and an imaging device, aiming to provide an 8K zoom optical system with small volume, large target surface, small distortion, short focusing object distance, and coaxial focusing at high and low temperatures.

[0005] To achieve the above object, the present invention provides a zoom optical system. The zoom optical system has an object side and an image side that are oppositely arranged along the optical axis direction. The zoom optical system includes 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 negative optical power, a fifth 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 fifth lens group are movably arranged along the optical axis extension direction to zoom the zoom optical system, and the fourth lens group moves cooperatively along the optical axis direction to focus the zoom optical system;

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

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

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

[0009] The fourth lens group includes a fourteenth lens with a negative optical power arranged in sequence from the object side to the image side;

[0010] The fifth lens group includes a fifteenth lens with a negative optical power, a sixteenth lens with a positive optical power, and a seventeenth lens with a negative optical power arranged in sequence from the object side to the image side.

[0011] In one embodiment, the zoom optical system further includes a diaphragm, and the diaphragm is disposed between the second lens group and the third lens group;

[0012] The distance from the diaphragm to the image plane is L, and the overall optical length of the zoom optical system is TTL, where 0.401 < L / TTL < 0.521.

[0013] In one embodiment, the first lens and the second lens are adhesively connected, the third lens and the fourth lens are adhesively connected, the seventh lens and the eighth lens are adhesively connected, the twelfth lens and the thirteenth lens are adhesively connected, and the sixteenth lens and the seventeenth lens are adhesively connected.

[0014] In one embodiment, the sixth lens, the ninth lens, the fourteenth lens, and the fifteenth lens are all aspherical lenses.

[0015] In one embodiment, the aperture of the first lens is D, and the overall optical length of the zoom optical system is TTL, where 0.32 < D / TTL < 0.415.

[0016] In one embodiment, the zoom optical system satisfies the following conditions:

[0017] 0.177 < S1 / TTL < 0.204, 0.045 < S3 / TTL < 0.059, 0.012 < S2 / TTL < 0.016; where,

[0018] 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 fifth 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.

[0019] 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 f21, the focal length of the sixth lens is f22, the focal length of the seventh lens is f23, the focal length of the eighth lens is f24, the focal length of the ninth lens is f31, the focal length of the tenth lens is f32, the focal length of the eleventh lens is f33, the focal length of the twelfth lens is f34, the focal length of the thirteenth lens is f35, the focal length of the fifteenth lens is f51, the focal length of the sixteenth lens is f52, the focal length of the seventeenth lens is f53; wherein,

[0020] -0.172 ≤ f11 / f1 ≤ -0.127, 0.824 ≤ f12 / f1 ≤ 0.959, 0.806 ≤ f13 / f1 ≤ 1.091, -0.804 ≤ f14 / f1 ≤ -0.595, 0.307 ≤ f21 / f2 ≤ 0.415, 0.714 ≤ f22 / f2 ≤ 0.966, 0.076 ≤ f23 / f2 ≤ 0.103, -0.399 ≤ f24 / f2 ≤ -0.295, 0.393 ≤ f31 / f3 ≤ 0.532, 0.274 ≤ f32 / f3 ≤ 0.371, 0.492 ≤ f33 / f3 ≤ 0.666, -1.928 ≤ f34 / f3 ≤ -1.425, 1.197 ≤ f35 / f3 ≤ 1.620, -58.770 ≤ f51 / f5 ≤ -43.439, 45.186 ≤ f52 / f5 ≤ 61.134, -2.603 ≤ f53 / f5 ≤ -1.924.

[0021] 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 fifth lens group is f5, and the focal length of the zoom optical system at the wide-angle end is f; wherein,

[0022] 0.547 ≤ f / f1 ≤ 0.636, -2.183 ≤ f / f2 ≤ -1.614, 1.620 ≤ f / f3 ≤ 2.191, -1.503 ≤ f / f4 ≤ -1.111, 0.018 ≤ f / f5 ≤ 0.024.

[0023] The present invention also provides an imaging device, which includes the above zoom optical system. The zoom optical system has an object side and an image side that are oppositely arranged along the optical axis direction. The zoom optical system includes 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 negative optical power, a fifth lens group with a positive optical power, a filter, and an image plane, which are arranged in sequence from the object side to the image side. Among them, the second lens group and the fifth lens group are movably arranged along the extending direction of the optical axis to zoom the zoom optical system, and the fourth lens group moves cooperatively along the optical axis direction to focus the zoom optical system;

[0024] The first lens group includes a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, and a fourth lens with a negative optical power, which are arranged in sequence from the object side to the image side;

[0025] The second lens group includes a fifth lens with a negative optical power, a sixth lens with a negative optical power, a seventh lens with a negative optical power, and an eighth lens with a positive optical power, which are arranged in sequence from the object side to the image side;

[0026] The third lens group includes a ninth lens with a positive optical power, a tenth lens with a positive optical power, an eleventh lens with a positive optical power, a twelfth lens with a negative optical power, and a thirteenth lens with a positive optical power, which are arranged in sequence from the object side to the image side;

[0027] The fourth lens group includes a fourteenth lens with a negative optical power, which is arranged in sequence from the object side to the image side;

[0028] The fifth lens group includes a fifteenth lens with a negative optical power, a sixteenth lens with a positive optical power, and a seventeenth lens with a negative optical power, which are arranged in sequence from the object side to the image side.

[0029] The technical solution provided by the present invention, by setting the first lens group with a positive optical power, undertakes a large optical power of the system, changes the propagation direction of the light beam, corrects the aberration of the off-axis field of view, and is more conducive to the light beam imaging on the image plane; by adopting a five-element structure, using seventeen lenses, and reasonably setting the optical power and shape matching relationship of each lens group and lens, an 8K zoom optical system with small volume, large target surface, small distortion, short focusing object distance, and co-focusing at high and low temperatures is realized. Description of the Drawings

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on the structures shown in these drawings.

[0031] Figure 1 Schematic structural diagram of an embodiment of the zoom optical system provided by the present invention;

[0032] Figure 2 For Figure 1 MTF schematic diagram of the zoom optical system in the 110 lp / mm frequency band at the wide-angle end;

[0033] Figure 3 For Figure 1 MTF schematic diagram of the zoom optical system in the 110 lp / mm frequency band at the intermediate magnification;

[0034] Figure 4 For Figure 1 MTF schematic diagram of the zoom optical system in the 110 lp / mm frequency band at the telephoto end;

[0035] Figure 5 For Figure 1 MTF schematic diagram of the zoom optical system at different fields of view at the wide-angle end;

[0036] Figure 6 For Figure 1 MTF schematic diagram of the zoom optical system at different fields of view at the intermediate magnification;

[0037] Figure 7 For Figure 1 MTF schematic diagram of the zoom optical system at different fields of view at the telephoto end;

[0038] Figure 8 For Figure 1 Defocus curve schematic diagram of the zoom optical system in the 110 lp / mm frequency band at the wide-angle end;

[0039] Figure 9 For Figure 1 Defocus curve schematic diagram of the zoom optical system in the 110 lp / mm frequency band at the intermediate magnification;

[0040] Figure 10 For Figure 1 Defocus curve schematic diagram of the zoom optical system in the 110 lp / mm frequency band at the telephoto end;

[0041] Figure 11 For Figure 1 Field curvature and distortion diagram of the zoom optical system at the wide-angle end;

[0042] Figure 12 is Figure 1 The field curvature and distortion diagram of the zoom optical system at the middle magnification;

[0043] Figure 13 is Figure 1 The field curvature and distortion diagram of the zoom optical system at the telephoto end;

[0044] Figure 14 is Figure 1 The fan diagram of the zoom optical system at the wide-angle end;

[0045] Figure 15 is Figure 1 The fan diagram of the zoom optical system at the middle magnification;

[0046] Figure 16 is Figure 1 The fan diagram of the zoom optical system at the telephoto end;

[0047] Figure 17 is Figure 1 The axial aberration curve diagram of the zoom optical system at the wide-angle end;

[0048] Figure 18 is Figure 1 The axial aberration curve diagram of the zoom optical system at the middle magnification;

[0049] Figure 19 is Figure 1 The axial aberration curve diagram of the zoom optical system at the telephoto end;

[0050] Figure 20 is Figure 1 The lateral chromatic aberration curve diagram of the zoom optical system at the wide-angle end;

[0051] Figure 21 is Figure 1 The lateral chromatic aberration curve diagram of the zoom optical system at the middle magnification;

[0052] Figure 22 is Figure 1 The lateral chromatic aberration curve diagram of the zoom optical system at the telephoto end.

[0053] Explanation of the reference numerals in the drawings:

[0054] 100, Zoom optical system; 1, First lens group; 11, First lens; 12, Second lens; 13, Third lens; 14, Fourth lens; 2, Second lens group; 21, Fifth lens; 22, Sixth lens; 23, Seventh lens; 24, Eighth lens; 3, Third lens group; 31, Ninth lens; 32, Tenth lens; 33, Eleventh lens; 34, Twelfth lens; 35, Thirteenth lens; 4, Fourth lens group; 41, Fourteenth lens; 5, Fifth lens group; 51, Fifteenth lens; 52, Sixteenth lens; 53, Seventeenth lens; 6, Diaphragm; 7, Filter; 8, Image plane.

[0055] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0058] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0059] A zoom optical lens is a camera lens that can change its focal length within a certain range, thereby obtaining different field angles of view with different widths, different sizes of images, and different ranges of scenes. In the field of video shooting, zoom optical systems have been widely used due to advantages such as long shooting distance and large shooting angle.

[0060] Currently, the mainstream video zoom optical lenses on the market have problems such as low clarity, large volume, unclear focusing at close object distances, and the target surface of the mainstream photosensitive chips on the market is relatively small, which can no longer meet the market demand. The demand for photosensitive chips with a 4 / 3″ target surface is gradually increasing, but the types of zoom optical systems that can match this photosensitive chip on the market are few and cannot meet the market demand.

[0061] The main objective of the present invention is to propose a zoom optical system and an imaging device, aiming to provide an 8K zoom optical system with small volume, large target surface, small distortion, short focusing object distance, and coaxial focusing at high and low temperatures.

[0062] Please refer to Figure 1 , the present invention proposes a zoom optical system 100. The zoom optical system 100 has an object side and an image side that are oppositely arranged along the optical axis direction. The zoom optical system 100 includes a first lens group 1 with a positive optical power, a second lens group 2 with a negative optical power, a third lens group 3 with a positive optical power, a fourth lens group 4 with a negative optical power, a fifth lens group 5 with a positive optical power, a filter 7, and an image plane 8, which are arranged in sequence from the object side to the image side. Among them, the second lens group 2 and the fifth lens group 5 are movably arranged along the optical axis extension direction to zoom the zoom optical system 100, and the fourth lens group 4 moves cooperatively along the optical axis direction to focus the zoom optical system 100; the first lens group 1 includes a first lens 11 with a negative optical power, a second lens 12 with a positive optical power, a third lens 13 with a positive optical power, and a fourth lens 14 with a negative optical power, which are arranged in sequence from the object side to the image side; the second lens group 2 includes a fifth lens 21 with a negative optical power, a sixth lens 22 with a negative optical power, a seventh lens 23 with a negative optical power, and an eighth lens 24 with a positive optical power, which are arranged in sequence from the object side to the image side; the third lens group 3 includes a ninth lens 31 with a positive optical power, a tenth lens 32 with a positive optical power, an eleventh lens 33 with a positive optical power, a twelfth lens 34 with a negative optical power, and a thirteenth lens 35 with a positive optical 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 a negative optical power, which is arranged in sequence from the object side to the image side; the fifth lens group 5 includes a fifteenth lens 51 with a negative optical power, a sixteenth lens 52 with a positive optical power, and a seventeenth lens 53 with a negative optical power, which are arranged in sequence from the object side to the image side.

[0063] The technical solution provided by the present invention, by setting the first lens group 1 with positive optical power, undertakes a relatively large optical power of the system, changes the propagation direction of the light beam, corrects the aberration of the off-axis field of view, and is more conducive to the light beam imaging on the image plane 8; by adopting a five-element structure, using seventeen lenses, and reasonably setting the optical power and shape matching relationship of each lens group and lens, an 8K zoom optical system 100 with small volume, large target surface, small distortion, short focusing object distance, and confocal at high and low temperatures is realized.

[0064] It should be noted that in this embodiment, there are two filter lenses 77, namely the first filter lens 7 and the second filter lens 7. The first filter lens 7 is used to filter infrared light and pass visible light, and the second filter lens 7 is used to pass infrared light and visible light. Both the first filter lens 7 and the second filter lens 7 are movably arranged so that one of them can move to the optical axis and the other moves away from the optical axis. By setting two mutually switchable filter lenses 77 to correspond to two working modes of the zoom optical system 100, the lens can achieve 4K image quality both day and night. By reasonably adjusting the thickness of the first filter lens 7 and the second filter lens 7, the imaging quality can be further improved.

[0065] Furthermore, the zoom optical system 100 further includes a diaphragm 6, which is arranged between the second lens group 2 and the third lens group 3. The diaphragm 6 limits the light passing aperture of the light beam on the optical axis, blocks part of the light, thereby reducing the light spot and improving the image contrast, and can also play a role in expanding the target surface and improving the image quality. According to the actual situation, adjusting the light flux of the diaphragm 6 helps to further improve the imaging quality. Wherein, the distance from the diaphragm 6 to the image plane 8 is L, and the overall optical length of the zoom optical system 100 is TTL, where 0.401 < L / TTL < 0.521. By limiting the position of the diaphragm 6, 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.

[0066] Furthermore, in order to enable the optical components to improve the image quality of the optical system, reduce light energy loss, increase imaging clarity, protect the scale surface, and further optimize the processing process to meet the design requirements, in this embodiment, the first lens 11 and the second lens 12 are adhesively connected, the third lens 13 and the fourth lens 14 are adhesively connected, the seventh lens 23 and the eighth lens 24 are adhesively connected, the twelfth lens 34 and the thirteenth lens 35 are adhesively connected, and the sixteenth lens 52 and the seventeenth lens 53 are adhesively connected. In this way, by reasonably using the adhesive parts and reasonably distributing the optical power, the aberration is well corrected and the effect of athermalization at high and low temperatures is achieved. It also effectively reduces chromatic aberration to achieve the effect that the imaging confocal planes of the visible light band and the near-infrared band are both clear.

[0067] Furthermore, the sixth lens 22, the ninth lens 31, the fourteenth lens 41, and the fifteenth lens 51 are all aspherical lenses. It should be noted that the characteristics of an aspherical lens are that the curvature continuously changes from the center of the lens to the periphery of the lens, which is different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens.

[0068] It should be further noted that the aspherical lenses in the zoom optical system 100 provided in the embodiments of the present invention can all adopt plastic aspherical lenses, and the lenses other than the aspherical lenses can adopt spherical glass lenses. Among them, these two types of materials, glass and plastic, can compensate for each other, so as to balance high and low temperatures and reduce the overall optical length of the lens, making the zoom optical system 100 have the characteristics of stable high and low temperature performance, improving the environmental adaptability of the zoom optical system 100, and at the same time being able to correct aberrations better. By reasonably matching the temperature coefficients of the glass-plastic hybrid materials, it can be ensured that the lens has good resolution in high and low temperature environments, and the weight of the lens can be significantly reduced. In addition, compared with glass lenses, the cost of plastic lenses also has obvious advantages, which can reduce the cost of the zoom optical system 100.

[0069] In this embodiment, specifically, please refer to Figure 1 , the first lens 11 is a convex-concave lens, and its object-side surface is a convex surface; the second lens 12 is a biconvex lens; the third lens 13 is a biconvex lens; the fourth lens 14 is a biconcave lens; the fifth lens 21 is a convex-concave lens, and its object-side surface is a convex surface; the sixth lens 22 is a biconcave lens; the seventh lens 23 is a convex-concave lens, and its object-side surface is a convex surface; the eighth lens 24 is a convex-concave lens, and its object-side surface is a convex surface; the ninth lens 31 is a convex-concave lens, and its object-side surface is a convex surface; the tenth lens 32 is a convex-concave lens, and its object-side surface is a convex surface; the eleventh lens 33 is a biconvex lens; the twelfth lens 34 is a biconcave lens; the thirteenth lens 35 is a biconvex lens; the fourteenth lens 41 is a convex-concave lens, and its object-side surface is a convex surface; the fifteenth lens 51 is a convex-concave lens, and its object-side surface is a concave surface; the sixteenth lens 52 is a convex-concave lens, and its object-side surface is a convex surface; the seventeenth lens 53 is a convex-concave lens, and its object-side surface is a convex surface.

[0070] Furthermore, the aperture of the first lens is D, and the overall optical length of the zoom optical system 100 is TTL, where 0.32 < D / TTL < 0.415. It should be noted that the first lens has the largest aperture among all the lenses of the zoom optical system 100. By limiting the aperture of the first lens, 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 being beneficial to achieving the effect of a large aperture.

[0071] Furthermore, the zoom optical system 100 satisfies the following conditions: 0.177 < S1 / TTL < 0.204, 0.045 < S3 / TTL < 0.059, 0.012 < S2 / TTL < 0.016; where S1 is the relative displacement of the second lens group 2 between the wide-angle end position and the telephoto end position of the zoom optical system 100, S2 is the relative displacement of the fourth lens group 4 between the wide-angle end position and the telephoto end position of the zoom optical system 100, S3 is the relative displacement of the fifth lens group 5 between the wide-angle end position and the telephoto end position of the zoom optical system 100, and TTL is the overall optical length of the zoom optical system 100. By controlling the moving distances of the second lens group, the fourth lens group 4, and the fifth lens group 5, the volume of the fifth lens group 5 can be greatly reduced, and thus the volume of the zoom optical system 100 can be greatly reduced.

[0072] Further, 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 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 f21, the focal length of the sixth lens 22 is f22, the focal length of the seventh lens 23 is f23, the focal length of the eighth lens 24 is f24, the focal length of the ninth lens 31 is f31, the focal length of the tenth lens 32 is f32, the focal length of the eleventh lens 33 is f33, the focal length of the twelfth lens 34 is f34, the focal length of the thirteenth lens 35 is f35, the focal length of the fifteenth lens 51 is f51, the focal length of the sixteenth lens 52 is f52, and the focal length of the seventeenth lens 53 is f53; where, -0.172 ≤ f11 / f1 ≤ -0.127, 0.824 ≤ f12 / f1 ≤ 0.959, 0.806 ≤ f13 / f1 ≤ 1.091, -0.804 ≤ f14 / f1 ≤ -0.595, 0.307 ≤ f21 / f2 ≤ 0.415, 0.714 ≤ f22 / f2 ≤ 0.966, 0.076 ≤ f23 / f2 ≤ 0.103, -0.399 ≤ f24 / f2 ≤ -0.295, 0.393 ≤ f31 / f3 ≤ 0.532, 0.274 ≤ f32 / f3 ≤ 0.371, 0.492 ≤ f33 / f3 ≤ 0.666, -1.928 ≤ f34 / f3 ≤ -1.425, 1.197 ≤ f35 / f3 ≤ 1.620, -58.770 ≤ f51 / f5 ≤ -43.439, 45.186 ≤ f52 / f5 ≤ 61.134, -2.603 ≤ f53 / f5 ≤ -1.924. By limiting the focal lengths of the respective lenses, a reasonable combination of the optical powers of the respective lenses can be achieved, enabling light to pass through the zoom optical system 100 relatively smoothly and correcting the influence of aberration on the imaging quality to a greater extent.

[0073] Further, 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 fifth lens group 5 is f5, and the focal length of the zoom optical system 100 at the wide-angle end is f; where, 0.547 ≤ f / f1 ≤ 0.636, -2.183 ≤ f / f2 ≤ -1.614, 1.620 ≤ f / f3 ≤ 2.191, -1.503 ≤ f / f4 ≤ -1.111, 0.018 ≤ f / f5 ≤ 0.024. By limiting the focal lengths of the respective lens groups, a reasonable combination of the optical powers of the respective lens groups can be achieved, enabling light to pass through the zoom optical system 100 relatively smoothly and correcting the influence of aberration on the imaging quality to a greater extent.

[0074] It should be noted that the surface shapes of the aspherical lenses in the zoom optical system 100 in this embodiment should satisfy the following equation:

[0075]

[0076] Where c is the curvature corresponding to the radius; y is the radial coordinate (with the same unit as the lens length unit); k is the conic quadratic curve coefficient, and A, B, C, D, E, F, G, H... respectively represent the aspherical coefficients of the fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, sixteenth order, eighteenth order... The shape dimensions of the aspherical surfaces facing the object side and the image side of the lens can be set through the above parameters.

[0077] Among them, when k < -1, the surface curve of the corresponding lens is a hyperbola; when k = -1, the surface curve of the corresponding lens is a parabola; when -1 < k < 0, the surface curve of the corresponding lens is an ellipse; when k = 0, the surface curve of the corresponding lens is a circle; when k > 0, the surface curve of the corresponding lens is an oblate circle.

[0078] It should be noted that the basic parameter table of the zoom optical system 100 in this embodiment is shown in Table 1, where the units of the radius of curvature, thickness, and focal length are all millimeters (mm).

[0079] Table 1

[0080]

[0081]

[0082]

[0083] It should be noted that the basic parameter tables of the zoom optical system 100 at the wide-angle end, medium magnification, and telephoto end in this embodiment are shown in Table 2, where the units of zoom 1, zoom 2, zoom 3, and focal length are all millimeters (mm).

[0084] Table 2

[0085] Wide-angle end Medium magnification Telephoto end Zoom 1 29.78 15.57 1.53 Zoom 2 13.37 12.37 18.61 Zoom 3 7.11 7.79 9.05 Focal length 50.14 83.68 149.22 Aperture value 2.33 3.1 3.5

[0086] In this embodiment, the aspherical coefficients of the aspherical lenses in the zoom optical system 100 include: the conic surface coefficient k, the fourth-order aspherical coefficient A, the sixth-order aspherical coefficient B, the eighth-order aspherical coefficient C, the tenth-order aspherical coefficient D, the twelfth-order aspherical coefficient E, the fourteenth-order aspherical coefficient F, the sixteenth-order aspherical coefficient G, and the eighteenth-order aspherical coefficient H of this surface, as shown in Table 3 below.

[0087] Table 3

[0088]

[0089] It is worth mentioning that the relevant dimensions of the zoom optical system 100 in this embodiment are shown in Table 4, and all parameter units in the table are millimeters (mm).

[0090] Table 4

[0091] Optical total length TTL 138.58 First lens aperture D 50.05 Displacement of the second lens group is S1 28.25 Displacement of the fourth lens group is S2 1.94 Displacement of the fifth lens group is S3 7.19 Distance from the diaphragm to the imaging surface L: 63.85

[0092] In this embodiment, D / TTL = 0.361, S1 / TTL = 0.204, S3 / TTL = 0.052, S2 / TTL = 0.014, L / TTL = 0.461, the aperture value F is between 2.33 and 3.5, and the distortion is between 1.41% and 2.07%. It can be seen that the zoom optical system 100 in this embodiment has the characteristics of small volume, large target surface, and small distortion.

[0093] In this embodiment, the focal lengths of each lens, the focal lengths of each lens group, the ratio of the focal length at the wide-angle end to the focal lengths of each lens group, and the ratio of the focal lengths of each lens group to the focal lengths of each lens within the group are shown in Table 5 below, where all focal length units are millimeters.

[0094] Table 5

[0095]

[0096]

[0097] Please refer to Figures 2 to 4 , which is the MTF schematic diagram of the zoom optical system 100 in this embodiment at 110 lp / mm frequency band at the wide-angle end, intermediate magnification, and telephoto end. It can be seen from the figure that the MTF basically exceeds 0.2 at 110 lp / mm frequency band, basically meeting the requirements of 4K imaging quality.

[0098] Please refer to Figures 5 to 7 , which is the MTF schematic diagram 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 basically exceeds 0.2 at different fields of view, basically meeting the requirements of 4K imaging quality.

[0099] Please refer to Figures 8 to 10 , which is the defocus curve schematic diagram of the zoom optical system 100 in this embodiment at 110 lp / mm frequency band at the wide-angle end, intermediate magnification, and telephoto end. It can be known from the figure that the defocus of the lens at the wide-angle end, intermediate magnification, and telephoto end basically does not exceed 10 μ, basically achieving the state of no defocus at high and low temperatures.

[0100] Please refer to Figures 11 to 13, which are the schematic diagrams of the field curvature and distortion of the zoom optical system 100 in the wide-angle end, medium magnification, and telephoto end in this embodiment. Different colors represent different wavelengths. The right curve of the same color is in the meridional direction, and the left curve is the sagittal field curvature. From the figure, it can be seen that the sagittal field curvature of this lens at the wide-angle end is no more than 20 μm, indicating that this lens can correct chromatic aberration well at the wide-angle end. Another curve in the figure is the distortion curve of the system. Distortion does not affect the clarity of the system, but it will cause image deformation of the system. The optical distortion of this system at the telephoto end is less than 5%.

[0101] Please refer to Figures 14 - 16 , which are the fan diagrams of the zoom optical system 100 in the wide-angle end, medium magnification, and telephoto end in this embodiment. The abscissa in the figure is the normalized beam aperture, and the ordinate is the lateral aberration. Ideally, each curve should completely coincide with the horizontal axis. At this time, all rays in the field of view focus on the same point on the image plane 5; the ordinate in the image can also represent the maximum dispersion range of the beam on the ideal image plane. The fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also represent the magnitude of the lateral chromatic aberration. It can be seen from the figure that the zoom optical system 100 closely approaches the horizontal axis at each wavelength in each field of view, indicating that the lateral aberration of each wavelength is well corrected. In addition, the curves of each color do not show obvious dispersion, indicating that this zoom optical system 100 also has good correction for chromatic aberration, ensuring the imaging requirement of the zoom optical system 100 to form clear images in the full wavelength band.

[0102] Please refer to Figures 17 - 19 , which are the axial aberration curve diagrams of the zoom optical system 100 in the wide-angle end, medium magnification, and telephoto end in this embodiment. The vertical direction represents the normalization of the aperture. 0 represents on the optical axis, and the vertex in the lateral direction represents the maximum pupil radius; the horizontal direction represents the offset relative to the main wavelength, with the unit of millimeter (mm). It can be seen from the figure that when the zoom optical system 100 is at the wide-angle end, the axial aberration of different wavelengths is basically controlled within the range of (-0.06 mm, +0.006 mm); when the zoom optical system 100 is at medium magnification, the axial aberration of different wavelengths is basically controlled within the range of (-0.05 mm, +0.035 mm); when the zoom optical system 100 is at the telephoto end, the axial aberration of different wavelengths is basically controlled within the range of (-0.08 mm, +0.03 mm), indicating that the axial aberration of the zoom optical system 100 at the wide-angle end, medium magnification, and telephoto end is well controlled and can meet the wide spectral application requirements of the full wavelength band.

[0103] Please refer to Figures 20 - 22, which is the vertical chromatic aberration curve graph of the zoom optical system 100 at the wide-angle end, medium magnification, and telephoto end in this embodiment. It can be seen from the figure that when the zoom optical system 100 is at the wide-angle end, the vertical chromatic aberration of different wavelengths is controlled within the range of (-3μm, +9μm); when the zoom optical system 100 is at the medium magnification, the vertical chromatic aberration of different wavelengths is controlled within the range of (-2μm, +2.5μm); when the zoom optical system 100 is at the telephoto end, the vertical chromatic aberration of different wavelengths is controlled within the range of (-10μm, +2μm), indicating that the vertical chromatic aberration of the zoom optical system 100 at the wide-angle end, medium magnification, and telephoto end is well controlled and can meet the wide-spectrum application requirements of the entire wavelength band.

[0104] The present invention also provides an imaging device. The imaging device 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 embodiment. Since the zoom optical system 100 of this imaging device adopts all the technical solutions of the above-mentioned all embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0105] The above is only an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied to 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 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 negative optical power, a fifth lens group with a positive optical power, a filter, and an image plane, which are arranged in sequence from the object side to the image side. Among them, the second lens group and the fifth lens group are movably arranged along the extending direction of the optical axis to zoom the zoom optical system, and the fourth 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 positive optical power, a third lens with a positive optical power, and a fourth lens with a negative optical power, which are arranged in sequence from the object side to the image side; The second lens group includes a fifth lens with a negative optical power, a sixth lens with a negative optical power, a seventh lens with a negative optical power, and an eighth lens with a positive optical power, which are arranged in sequence from the object side to the image side; The third lens group includes a ninth lens with a positive optical power, a tenth lens with a positive optical power, an eleventh lens with a positive optical power, a twelfth lens with a negative optical power, and a thirteenth lens with a positive optical power, which are arranged in sequence from the object side to the image side; The fourth lens group includes a fourteenth lens with a negative optical power, which is arranged in sequence from the object side to the image side; The fifth lens group includes a fifteenth lens with a negative optical power, a sixteenth lens with a positive optical power, and a seventeenth lens with a negative optical power, which are 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 a diaphragm, and the diaphragm is disposed between the second lens group and the third lens group; The distance from the diaphragm to the image plane is L, and the overall optical length of the zoom optical system is TTL, where 0.401 < L / TTL < 0.

521.

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

4. The zoom optical system according to claim 1, wherein The sixth lens, the ninth lens, the fourteenth lens, and the fifteenth lens are all aspherical lenses.

5. The zoom optical system according to claim 1, characterized in that, The aperture of the first lens is D, and the overall optical length of the zoom optical system is TTL, where 0.32 < D / TTL < 0.

415.

6. The zoom optical system according to claim 1, wherein, The zoom optical system satisfies the following conditions: 0.177 < S1 / TTL < 0.204, 0.045 < S3 / TTL < 0.059, 0.012 < S2 / TTL < 0.016; 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 fifth 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, characterized in that, 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 f21, the focal length of the sixth lens is f22, the focal length of the seventh lens is f23, the focal length of the eighth lens is f24, the focal length of the ninth lens is f31, the focal length of the tenth lens is f32, the focal length of the eleventh lens is f33, the focal length of the twelfth lens is f34, the focal length of the thirteenth lens is f35, the focal length of the fifteenth lens is f51, the focal length of the sixteenth lens is f52, and the focal length of the seventeenth lens is f53; wherein, -0.172 ≤ f11 / f1 ≤ -0.127, 0.824 ≤ f12 / f1 ≤ 0.959, 0.806 ≤ f13 / f1 ≤ 1.091, -0.804 ≤ f14 / f1 ≤ -0.595, 0.307 ≤ f21 / f2 ≤ 0.415, 0.714 ≤ f22 / f2 ≤ 0.966, 0.076 ≤ f23 / f2 ≤ 0.103, -0.399 ≤ f24 / f2 ≤ -0.295, 0.393 ≤ f31 / f3 ≤ 0.532, 0.274 ≤ f32 / f3 ≤ 0.371, 0.492 ≤ f33 / f3 ≤ 0.666, -1.928 ≤ f34 / f3 ≤ -1.425, 1.197 ≤ f35 / f3 ≤ 1.620, -58.770 ≤ f51 / f5 ≤ -43.439, 45.186 ≤ f52 / f5 ≤ 61.134, -2.603 ≤ f53 / f5 ≤ -1.

924.

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, the focal length of the fifth lens group is f5, and the focal length of the zoom optical system at the wide-angle end is f; wherein, 0.547 ≤ f / f1 ≤ 0.636, -2.183 ≤ f / f2 ≤ -1.614, 1.620 ≤ f / f3 ≤ 2.191, -1.503 ≤ f / f4 ≤ -1.111, 0.018 ≤ f / f5 ≤ 0.

024.

9. An imaging device, characterized in that, Comprising the zoom optical system according to any one of claims 1-8.

Images