Zoom optical system and imaging equipment

Abstract

The utility model discloses a zoom optical system and imaging equipment, the zoom optical system is provided with an object side and an image side which are oppositely arranged along the optical axis direction, the zoom optical system comprises a lens barrel and a plurality of lens groups arranged in the lens barrel, the multiple lens sets sequentially comprise the first lens set, the second lens set, the third lens set, the fourth lens set and the fifth lens set from the object side to the image side, and through reasonable arrangement of the five lens sets and conditional limitation of the ratio of the focal length of the wide-angle end of the zoom system to the focal length of all the lens sets, under the condition that the size of the image plane is set to be # imgabs0 #, the focal length of the wide-angle end of the zoom system is larger than that of the fifth lens set. The focal length fw at the wide-angle end is 5.2 mm, and the focal length ft at the telephoto end is 130.0 mm; according to the zoom optical system, the aperture number of the wide-angle end reaches 1.73, the aperture number of the telephoto end reaches 4.3, the optical distortion range is controlled between-4% and 4%, and the total optical length TTL of the zoom optical system is only 91.8 mm, so that the zoom optical system and the imaging equipment which are high in imaging quality, small in size, low in cost and wide in application environment are provided.

Description

Technical Field

[0001] The utility model relates to the technical field of optics, and particularly relates to a zoom optical system and an imaging device. Background Art

[0002] With the rapid development of the security monitoring industry, the zoom optical system of the high-image-quality monitoring system plays an increasingly important role. At present, the mainstream zoom optical system of the high-image-quality monitoring system is often larger in volume when it has a higher magnification, and generally uses multiple glass aspherical lenses to improve the lens resolution, resulting in a higher manufacturing cost. Content of the Utility Model

[0003] The main purpose of the utility model is to provide a zoom optical system and an imaging device, aiming to provide a zoom optical system and an imaging device with high imaging quality, small volume and low cost.

[0004] To achieve the above object, a zoom optical system proposed by the utility model is characterized in that the zoom optical system has an object side and an image side which are oppositely arranged along the optical axis direction, and the zoom optical system includes a lens barrel and a plurality of lens groups arranged in the lens barrel. The plurality of lens groups successively include from the object side to the image side:

[0005] A first lens group, fixedly arranged in the lens barrel and having a positive optical power;

[0006] A second lens group, movably mounted in the lens barrel along the optical axis direction and having a negative optical power;

[0007] A third lens group, fixedly arranged in the lens barrel and having a positive optical power;

[0008] A fourth lens group, movably mounted in the lens barrel along the optical axis direction and having a positive optical power; and,

[0009] A fifth lens group, fixedly arranged in the lens barrel;

[0010] Wherein, the focal length of the zoom optical system at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the focal length of the fifth lens group is f5;

[0011] The following conditions are satisfied in the zoom optical system:

[0012] 0.099 < fw / f1 < 0.149, and -0.888 < fw / f2 < -0.592, and 0.169 < fw / f3 < 0.253, and 0.246 < fw / f4 < 0.369, and -0.1 < fw / f5 < 0.1.

[0013] Optionally, the first lens group includes a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side;

[0014] The second lens group includes a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side;

[0015] The third lens group includes an eighth lens, a ninth lens, a tenth lens, and an eleventh lens arranged in sequence from the object side to the image side;

[0016] The fourth lens group includes a twelfth lens, a thirteenth lens, and a fourteenth lens arranged in sequence from the object side to the image side;

[0017] The fifth lens group includes a fifteenth lens.

[0018] Optionally, the first lens has a negative focal power, the second lens has a positive focal power, the third lens has a positive focal power, and the fourth lens has a positive focal power;

[0019] Wherein, 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, and the focal length of the fourth lens is f14;

[0020] Each lens in the first lens group satisfies the following conditions:

[0021] -0.806 < f1 / f11 < -0.537, and 0.547 < f1 / f12 < 0.821, and 0.446 < f1 / f13 < 0.67, and 0.387 < f1 / f14 < 0.581.

[0022] Optionally, the fifth lens has a negative focal power, the sixth lens has a negative focal power, and the seventh lens has a positive focal power;

[0023] Wherein, the focal length of the fifth lens is f21, the focal length of the sixth lens is f22, and the focal length of the seventh lens is f23;

[0024] Each lens in the second lens group satisfies the following conditions:

[0025] 0.617 < f2 / f21 < 0.925, and 0.504 < f2 / f22 < 0.757, and -0.511 < f2 / f23 < -0.341.

[0026] Optionally, the eighth lens has a positive focal power, the ninth lens has a positive focal power concentrated thereon, the tenth lens has a negative focal power, and the eleventh lens has a negative focal power;

[0027] Among them, the focal length of the eighth lens is f31, the focal length of the ninth lens is f32, the focal length of the tenth lens is f33, and the focal length of the eleventh lens is f34;

[0028] Each lens in the third lens group satisfies the following conditions:

[0029] 1.105 < f3 / f31 < 1.658, and 0.444 < f3 / f32 < 0.665, and -0.39 < f3 / f33 < -0.26, and -1.26 < f3 / f34 < -0.84.

[0030] Optionally, the twelfth lens has a positive optical power, the thirteenth lens has a negative optical power, and the fourteenth lens has a positive optical power;

[0031] Among them, the focal length of the twelfth lens is f41, the focal length of the thirteenth lens is f42, and the focal length of the fourteenth lens is f43;

[0032] Each lens in the fourth lens group satisfies the following conditions:

[0033] 0.404 < f4 / f41 < 0.606, and -0.722 < f4 / f42 < -0.482, and 0.931 < f4 / f43 < 1.396.

[0034] Optionally, the zoom optical system satisfies the following conditions:

[0035] 0.279 < ΔZW-T / TTL < 0.362;

[0036] Among them, ΔZW-T is the relative displacement amount of the fourth lens 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.

[0037] Optionally, the first lens, the second lens, the third lens, and the fourth lens are all glass spherical lenses;

[0038] The fifth lens is a glass spherical lens, and the sixth lens and the seventh lens are plastic aspherical lenses;

[0039] The eighth lens is a glass lens, the ninth lens is a glass spherical lens, the tenth lens is a plastic aspherical lens, and the eleventh lens is a glass spherical lens;

[0040] The twelfth lens is a plastic aspherical lens, and the thirteenth lens and the fourteenth lens are glass spherical lenses;

[0041] The fifteenth lens is a plastic aspherical lens.

[0042] Optionally, the zoom optical system further includes a diaphragm, and the diaphragm is located between the second lens group and the third lens group; the zoom optical system satisfies the following conditions:

[0043] 0.337 < L / TTL < 0.456;

[0044] wherein, L is the distance from the diaphragm to the imaging surface of the zoom optical system on the optical axis, and TTL is the overall optical length of the zoom optical system.

[0045] The present utility model also provides an imaging device, the imaging device includes a zoom optical system, and the zoom optical system is characterized in that the zoom optical system has an object side and an image side that are oppositely arranged along the optical axis direction, and the zoom optical system includes a lens barrel and a plurality of lens groups arranged in the lens barrel. The plurality of lens groups sequentially include from the object side to the image side:

[0046] A first lens group, fixedly arranged in the lens barrel, having a positive optical power;

[0047] A second lens group, movably mounted in the lens barrel along the optical axis direction, having a negative optical power;

[0048] A third lens group, fixedly arranged in the lens barrel, having a positive optical power;

[0049] A fourth lens group, movably mounted in the lens barrel along the optical axis direction, having a positive optical power; and,

[0050] A fifth lens group, fixedly arranged in the lens barrel, having a positive optical power;

[0051] wherein, the focal length of the zoom optical system at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the focal length of the fifth lens group is f5;

[0052] In the zoom optical system, the following conditions are satisfied:

[0053] 0.099 < fw / f1 < 0.149, and -0.888 < fw / f2 < -0.592, and 0.169 < fw / f3 < 0.253, and 0.246 < fw / f4 < 0.369, and -0.1 < fw / f5 < 0.1.

[0054] In the technical solution provided by the utility model, the second lens group and the fourth lens group are movably installed in the lens barrel along the optical axis direction, the second lens group is used for zooming, and the fourth lens group moves in coordination along the optical axis direction to perform mobile focusing corresponding to the position, imaging wavelength, and imaging object distance of the second lens group, so that the zoom optical system can keep the image plane clear during the zooming process, and the image plane size is set to Through the reasonable arrangement of the five lens groups and the conditional restriction of the ratio of the focal length at the wide-angle end of the zoom optical system and the focal length of each lens group, the focal length fw at the wide-angle end is 5.2 mm, and the focal length ft at the telephoto end is 130.0 mm; the aperture number at the wide-angle end reaches 1.73, the aperture number at the telephoto end reaches 4.3, the optical distortion range is controlled between -□4% and 4%, and the total optical length TTL of the zoom optical system is only 91.8 mm, and it can work stably during the day and at night and in an environment with a large temperature difference, so as to provide a zoom optical system and imaging equipment with high imaging quality, small size, low cost and a wide application environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0056] Figure 1 A schematic structural diagram of an embodiment of a zoom optical system provided by the utility model when it is at a wide-angle end;

[0057] Figure 2 is a schematic diagram of the structure of the zoom optical system when it is at an intermediate magnification;

[0058] Figure 3 is a schematic diagram of the structure of the zoom optical system when it is at the telephoto end;

[0059] Figure 4 for Figure 1 Aberration diagram of the zoom optical system at the wide-angle end;

[0060] Figure 5 for Figure 1 Field curvature / distortion diagram of the zoom optical system at the wide-angle end;

[0061] Figure 6 for Figure 2 Aberration diagram of the zoom optical system when it is at an intermediate magnification;

[0062] Figure 7 for Figure 2 Field curvature / distortion diagram of the zoom optical system at intermediate magnifications;

[0063] Figure 8 for Figure 3 Aberration diagram when the zoom optical system is at the telephoto end;

[0064] Fig. 9 for Figure 3 Field curvature / distortion diagram when the zoom optical system is at the telephoto end.

[0065] Description of Figure Numbers:

[0066] Label name Label name 1000 Zoom optical system 32 The ninth lens 1 First lens group 33 Tenth lens 11 First lens 34 Eleventh lens 12 Second lens 4 The fourth lens group 13 The third lens 41 Twelfth lens 14 The fourth lens 42 Thirteenth lens 2 Second lens group 43 Fourteenth lens 21 Fifth lens 5 Fifth lens group 22 The sixth lens 51 The fifteenth lens 23 Seventh lens 6 Optical Filters 3 The third lens group 7 Aperture 31 The eighth lens 8 Image plane

[0067] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0069] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0070] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies 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 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 utility model.

[0071] With the rapid development of the security monitoring industry, the zoom optical system of high-image-quality monitoring systems plays an increasingly important role. At present, for the mainstream zoom optical systems of high-image-quality monitoring systems, when they have a higher magnification, they often have a larger volume, and generally use multiple glass aspherical lenses to improve the lens resolution, which in turn leads to a higher manufacturing cost.

[0072] To solve the above problems, the present utility model proposes a zoom optical system and an imaging device, aiming to provide a zoom optical system and an imaging device with high imaging quality, small volume, and low cost. Figures 1 to 9 This is an embodiment of a zoom optical system of the present utility model.

[0073] Please refer to Figures 1 to 3 , the present utility model proposes a zoom optical system 1000. The zoom optical system 1000 has an object side and an image side that are oppositely arranged along the optical axis direction. The zoom optical system 1000 includes a lens barrel and a plurality of lens groups disposed in the lens barrel. The plurality of lens groups sequentially include a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4, and a fifth lens group 5 from the object side to the image side. The first lens group 1 is fixedly disposed in the lens barrel and has a positive optical power. The second lens group 2 is movably mounted in the lens barrel along the optical axis direction and has a negative optical power. The third lens group 3 is fixedly disposed in the lens barrel and has a positive optical power. The fourth lens group 4 is movably mounted in the lens barrel along the optical axis direction and has a positive optical power. The fifth lens group 5 is fixedly disposed in the lens barrel. Among them, the focal length of the zoom optical system 1000 at the wide-angle end is fw, the focal length of the first lens group 1 is f1, the focal length of the second lens group 2 is f2, the focal length of the third lens group 3 is f3, the focal length of the fourth lens group 4 is f4, and the focal length of the fifth lens group 5 is f5. In the zoom optical system 1000, the following conditions are satisfied:

[0074] 0.099 < fw / f1 < 0.149, and -0.888 < fw / f2 < -0.592, and 0.169 < fw / f3 < 0.253, and 0.246 < fw / f4 < 0.369, and -0.1 < fw / f5 < 0.1.

[0075] It can be understood that fw / f1 can be set to 0.100, 0.105, 0.110, 0.115, 0.120, 0.125, 0.130, 0.135, 0.140, 0.145, etc.; fw / f2 can be set to -0.850, -0.800, -0.750, -0.700, -0.650, -0.600, etc.; fw / f3 can be set to 0.160, 0.170, 0.180, 0. 190, 0.200, 0.21, 0.22, 0.23, 0.24, 0.25, etc.; fw / f4 can be set to 0.247, 0.260, 0.280, 0.290, 0.300, 0.320, 0.340, 0.360, etc.; fw / f5 can be set to -0.09, -0.07, -0.05, -0.03, -0.01, 0.01, 0.03, 0.05, 0.07, 0.09, etc.;

[0076] In the technical solution provided by the utility model, the second lens group 2 and the fourth lens group 4 are movably installed in the lens barrel along the optical axis direction, the second lens group 2 is used for zooming, and the fourth lens group 4 moves in coordination along the optical axis direction to perform mobile focusing corresponding to the position, imaging wavelength, and imaging object distance of the second lens group 2, so that the zoom optical system 1000 can keep the image plane 8 clear during the zooming process, and the size of the image plane 8 is set to By reasonably setting the five lens groups and conditionally limiting the focal length of the zoom optical system 1000 at the wide-angle end and the focal length ratio of each lens group, the focal length fw at the wide-angle end is 5.2mm, and the focal length ft at the telephoto end is 130.0mm; the aperture number at the wide-angle end reaches 1.73, and the aperture number at the telephoto end reaches 4.3, and the optical distortion range is controlled between -□4% and 4%, and the total optical length TTL of the zoom optical system 1000 is only 91.8mm, and it can work stably during the day and at night, and in an environment with a large temperature difference, so as to provide a zoom optical system 1000 and an imaging device with high imaging quality, small size, low cost and a wide application environment.

[0077] Specifically, the first lens group 1 includes a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14 arranged in sequence from the object side to the image side; the second lens group 2 includes a fifth lens 21, a sixth lens 22, and a seventh lens 23 arranged in sequence from the object side to the image side; the third lens group 3 includes an eighth lens 31, a ninth lens 32, a tenth lens 33, and an eleventh lens 34 arranged in sequence from the object side to the image side; the fourth lens group 4 includes a twelfth lens 41, a thirteenth lens 42, and a fourteenth lens 43 arranged in sequence from the object side to the image side; the fifth lens group 5 includes a fifteenth lens 51. In this way, the technical parameters achievable by the present invention can be achieved specifically by setting the above fifteen lenses. Of course, it can be understood that the first lens group 1, the second lens group 2, the third lens group 3, the fourth lens group 4, and the fifth lens group 5 may also include other combination forms. Each lens group is restricted by comprehensive constraints such as the number, material, refractive index, and focal length of the lenses. Finally, the combination forms within the range of 0.099 < fw / f1 < 0.149, -0.888 < fw / f2 < -0.592, 0.169 < fw / f3 < 0.253, 0.246 < fw / f4 < 0.369, and -0.1 < fw / f5 < 0.1 of the zoom optical system 1000 are all within the protection scope of this application.

[0078] Specifically, the first lens 11 has a negative optical power, the second lens 12 has a positive optical power, the third lens 13 has a positive optical power, and the fourth lens 14 has a positive optical power; wherein, 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, and the focal length of the fourth lens 14 is f14; each lens within the first lens group 1 satisfies the following conditions: -0.806 < f1 / f11 < -0.537, 0.547 < f1 / f12 < 0.821, 0.446 < f1 / f13 < 0.67, and 0.387 < f1 / f14 < 0.581. More specifically, in this embodiment, the first lens 11 is a convex-concave spherical lens with a negative optical power, that is, the object side surface of the first lens 11 is convex and the image side surface is concave; the second lens 12 is a biconvex spherical lens with a positive optical power; the third lens 13 is a convex-concave spherical lens with a positive optical power, that is, the object side surface of the third lens 13 is convex and the image side surface is concave; the fourth lens 14 is a convex-concave spherical lens with a positive optical power, that is, the object side surface of the fourth lens 14 is convex and the image side surface is concave.

[0079] It can be understood that f1 / f11 can be set to -0.800, -0.750, -0.700, -0.650, -0.600, -0.550, etc.; f1 / f12 can be set to 0.550, 0.600, 0.650, 0.700, 0.750, 0.800, etc.; f1 / f13 can be set to 0.450, 0.500, 0.550, 0.600, 0.650, etc.; f1 / f14 can be set to 0.400, 0.420, 0.440, 0.460, 0.480, 0.500, 0.520, 0.540, 0.560, 0.580, etc.

[0080] Specifically, the fifth lens 21 has a negative optical power, the sixth lens 22 has a negative optical power, and the seventh lens 23 has a positive optical power; wherein, the focal length of the fifth lens 21 is f21, the focal length of the sixth lens 22 is f22, and the focal length of the seventh lens 23 is f23; each lens in the second lens group 2 satisfies the following conditions: 0.617 < f2 / f21 < 0.925, and 0.504 < f2 / f22 < 0.757, and -0.511 < f2 / f23 < -0.341. More specifically, in this embodiment, the fifth lens 21 is a convex-concave spherical lens with a negative optical power, that is, the object side of the fifth lens 21 is convex and the image side is concave; the sixth lens 22 is a biconcave aspherical lens with a negative optical power; the seventh lens 23 is an aspherical lens with a positive optical power.

[0081] It can be understood that f2 / f21 can be set to 0.650, 0.700, 0.750, 0.800, 0.850, 0.900, etc.; f2 / f22 can be set to 0.550, 0.600, 0.650, 0.700, 0.750, etc.; f2 / f23 can be set to -0.500, -0.450, -0.400, -0.350, etc.

[0082] Specifically, the eighth lens 31 has a positive optical power, the ninth lens 32 has a positive optical power, the tenth lens 33 has a negative optical power, and the eleventh lens 34 has a negative optical power; wherein, the focal length of the eighth lens 31 is f31, the focal length of the ninth lens 32 is f32, the focal length of the tenth lens 33 is f33, and the focal length of the eleventh lens 34 is f34; for each lens in the third lens group 3, the following conditions are satisfied: 1.105 < f3 / f31 < 1.658, and 0.444 < f3 / f32 < 0.665, and -0.39 < f3 / f33 < -0.26, and -1.26 < f3 / f34 < -0.84. More specifically, in this embodiment, the eighth lens 31 is a biconvex spherical lens with a positive optical power; the ninth lens 32 is a biconvex spherical lens with a positive optical power; the tenth lens 33 is an aspherical lens with a negative optical power; the eleventh lens 34 is a convex-concave spherical lens with a negative optical power, that is, the object side surface of the eleventh lens 34 is a convex surface and the image side surface is a concave surface.

[0083] It can be understood that f3 / f31 can be set to 1.150, 1.200, 1.250, 1.300, 1.350, 1.400, 1.450, 1.500, 1.650, etc.; f3 / f32 can be set to 0.445, 0.480, 0.520, 0.540, 0.560, 0.600, 0.620, 0.640, 0.660, etc.; f3 / f33 can be set to -0.380, -0.350, -0.320, -0.300, -0.280, -0.250, etc.; f3 / f34 can be set to -1.250, -1.100, -1.000-, -0.900, -0.830, etc.

[0084] Specifically, the twelfth lens 41 has a positive optical power, the thirteenth lens 42 has a negative optical power, and the fourteenth lens 43 has a positive optical power; wherein, the focal length of the twelfth lens 41 is f41, the focal length of the thirteenth lens 42 is f42, and the focal length of the fourteenth lens 43 is f43; for each lens in the fourth lens group 4, the following conditions are satisfied: 0.404 < f4 / f41 < 0.606, and -0.722 < f4 / f42 < -0.482, and 0.931 < f4 / f43 < 1.396. More specifically, in this embodiment, the twelfth lens 41 is an aspherical lens with a positive optical power; the thirteenth lens 42 is a convex-concave spherical lens with a negative optical power, that is, the object side surface of the thirteenth lens 42 is a convex surface and the image side surface is a concave surface; the fourteenth lens 43 is a biconvex spherical lens with a positive optical power.

[0085] It can be understood that f4 / f41 can be set to 0.410, 0.450, 0.500, 0.550, 0.600, etc.; f4 / f42 can be set to -0.720, -0.650, -0.600, -0.55, -0.5, -0.4, -0.45, etc.; f4 / f43 can be set to 0.935, 1.0, 1.05, 1.2, 1.25, 1.3, 1.35, etc.

[0086] Further, in this embodiment, the zoom optical system 1000 satisfies the following condition: 0.279<ΔZW-T / TTL<0.362; wherein ΔZW-T is the relative displacement of the fourth lens 14 when the zoom optical system 1000 is at the wide-angle end position and when the zoom optical system 1000 is at the telephoto end position, and TTL is the total optical length of the zoom optical system 1000. Specifically, the size of the image plane 8 in this embodiment is set to The following performance parameters are achieved: focal length fw at wide angle = 5.2mm, focal length ft at telephoto = 130.0mm; aperture number at wide angle = 1.73, aperture number at telephoto = 4.3; optical distortion range is between -□4% and 4%; the total optical length TTL of the zoom optical system 1000 = 91.8mm.

[0087] It is understandable that ΔZW-T / TTL can be set to 0.280, 0.290, 0.300, 0.310, 0.320, 0.330, 0.340, 0.350, 0.360, etc.

[0088] Further, in this embodiment, the first lens 11, the second lens 12, the third lens 13 and the fourth lens 14 are all glass spherical lenses; the fifth lens 21 is a glass spherical lens, the sixth lens 22 and the seventh lens 23 are plastic aspherical lenses; the eighth lens 31 is a glass aspherical lens, the ninth lens 32 is a glass spherical lens, the tenth lens 33 is a plastic aspherical lens, and the eleventh lens 34 is a glass spherical lens; the twelfth lens 41 is a plastic aspherical lens, the thirteenth lens 42 and the fourteenth lens 43 are glass spherical lenses; and the fifteenth lens 51 is a plastic aspherical lens.

[0089] It is understandable that, because the resin material is light in weight and highly plastic, it can be made into aspherical lenses, and the cost is also low. Therefore, in the present embodiment, a glass-plastic hybrid method is adopted, which saves costs on the one hand, and on the other hand, setting the plastic lens as an aspherical lens is beneficial to improving the imaging quality; the zoom optical system 1000 uses plastic lenses, but under the condition that the focal length is conditionally restricted, the stability of the system is guaranteed when the ambient temperature changes.

[0090] It should be noted that the characteristic of aspheric lenses is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike spherical lenses with constant curvature from the center of the lens to the periphery of the lens, aspheric lenses have better curvature radius characteristics and have the advantages of improving distortion aberration and improving astigmatism aberration. After using aspheric lenses, the aberrations that occur during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens.

[0091] By reasonably distributing the lens power, adjusting the shape of the plastic material and the material combination, effectively eliminating chromatic aberration and secondary spectrum, the spherical aberration, coma, astigmatism, etc. on each lens compensate and cancel each other out to achieve a clear imaging effect, so as to achieve the optimal correction of high-order aberrations and chromatic aberrations.

[0092] Specifically, in this embodiment, please refer to Table 1, in which the surface type, curvature radius, thickness, semi-aperture, material refractive index, material Abbe number, focal length and other related parameters of each lens are described in detail:

[0093] Table 1: Parameters of each lens in the optical system

[0094]

[0095]

[0096] Further, in this embodiment, the aspheric surface shape of the aspheric lens satisfies the following conditions:

[0097]

[0098] Wherein, c is the curvature corresponding to the radius, y is the radial coordinate (its unit is the same as the lens length unit), k is the coefficient of the conic quadratic curve (when the k coefficient is less than -1, the surface curve is a hyperbola, when the k coefficient is equal to -1, it is a parabola, when the k coefficient is between -1 and 0, it is an ellipse, when the k coefficient is equal to 0, it is a circle, and when the k coefficient is greater than 0, it is an oblate circle), A, B, C, D are high-order aspheric coefficients;

[0099] Please refer to Table 2, which details the conic coefficient and aspheric coefficient of the aspheric lens:

[0100] Table 2: Conic coefficients and aspheric coefficients corresponding to aspheric lenses

[0101]

[0102] Further, in this embodiment, the zoom optical system 1000 further includes a diaphragm 7, and the diaphragm 7 is located between the second lens group 2 and the third lens group 3; the zoom optical system 1000 satisfies the following condition: 0.337 < L / TTL < 0.456; where L is the distance from the diaphragm 7 to the imaging surface 8 of the zoom optical system 1000 on the optical axis, and TTL is the total optical length of the zoom optical system 1000. The diaphragm 7 restricts the light passing aperture of the on-axis beam to block part of the light during the zoom process, reduces the light spot, improves the image contrast, and helps to improve the image quality.

[0103] It can be understood that L / TTL can be set to 0.340, 0.350, 0.360, 0.370, 0.380, 0.390, 0.400, 0.410, 0.420, 0.430, 0.440, 0.450, etc.

[0104] Specifically, in this embodiment, the zoom system further includes a filter 6, and the filter 6 is located between the fifth lens group 5 and the image surface 8. The filter 6 is used to filter unnecessary wavelength bands of light and stray light to reduce the optical noise, making it easier for the subsequent optoelectronic module processing part, and the filter 6 can also be used to adjust the color degree of the object image during the final imaging, thereby improving the imaging quality.

[0105] Specifically, the image surface 8 can be understood as the surface of the photosensitive chip facing the object side, that is, it can be the surface of a CCD or CMOS imaging element, etc. It can be understood that the light carrying the information of the object to be photographed can sequentially pass through the first lens group 1, the second lens group 2, the diaphragm 7, the third lens group 3, the fourth lens group 4, the fifth lens group 5, the filter 6 and finally form an image on the image surface 8.

[0106] Specifically, the size of the image surface 8 in this embodiment is set to Reach the following performance parameters:

[0107] The focal length at the wide-angle end fw = 5.2 mm, the focal length at the telephoto end ft = 130.0 mm; the aperture number at the wide-angle end = 1.73, the aperture number at the telephoto end = 4.3; the optical distortion range is between -□4% and 4%; the total optical length TTL of the zoom system = 91.8 mm.

[0108] Please refer to Table 3. In Table 3, the zoom data and other related parameters of the zoom system at different magnifications (wide-angle, intermediate magnification, and telephoto) are introduced in detail:

[0109] Table 3 shows the zoom data of the zoom system at the wide-angle end, the intermediate magnification position, and the telephoto end;

[0110] Wide angle Intermediate magnification Telephoto T(7) 0.55 28.16 29.94 T(13) 30.59 2.97 1.20 T(20) 8.51 6.13 14.62 T(26) 7.34 9.73 1.23

[0111] In this embodiment, please refer to Figures 1 to 3 , which is a schematic diagram of the structure of the zoom optical system 1000 when it is at the wide-angle end, the intermediate magnification, and the telephoto end respectively; wherein the intermediate magnification can be understood as a schematic diagram of the position of each lens group in the zoom optical system 1000 when the zoom optical system 1000 is between the wide-angle end and the telephoto end.

[0112] Figures 4 to 5 The aberration diagram (longitudinalaberration) and the field curvature diagram (field curvature) / distortion diagram (distortion) when the zoom optical system 1000 is at the wide-angle end are respectively shown, and S and T in the figure are the aberrations corresponding to the sagittal plane and the meridional plane, respectively.

[0113] Please refer to Figure 6 to Figure 7 , are aberration diagrams, field curvature diagrams / distortion diagrams when the zoom optical system 1000 is at an intermediate magnification, where S and T are aberrations corresponding to the sagittal plane and the meridional plane, respectively.

[0114] Please refer to Figures 8 to 9 , which are spherical aberration diagrams and field curvature diagrams / distortion diagrams when the zoom optical system 1000 is at the telephoto end, where S and T are aberrations corresponding to the sagittal plane and the meridional plane, respectively.

[0115] It can be seen from the above figures that the spherical aberration, field curvature and distortion of the zoom optical system 1000 in this embodiment can be well corrected at the intermediate magnification, wide-angle end and telephoto end respectively.

[0116] The utility model further proposes an imaging device, which includes a zoom optical system 1000. The specific structure of the zoom optical system 1000 refers to the above-mentioned embodiment. Since the imaging device adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0117] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are 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 which are oppositely arranged along the optical axis direction, and the zoom optical system includes a lens barrel and a plurality of lens groups arranged in the lens barrel. The plurality of lens groups successively include from the object side to the image side: a first lens group, fixedly arranged in the lens barrel and having a positive optical power; a second lens group, movably mounted in the lens barrel along the optical axis direction and having a negative optical power; a third lens group, fixedly arranged in the lens barrel and having a positive optical power; a fourth lens group, movably mounted in the lens barrel along the optical axis direction and having a positive optical power; and a fifth lens group, fixedly arranged in the lens barrel; wherein, the focal length of the zoom optical system at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the focal length of the fifth lens group is f5; in the zoom optical system, the following conditions are satisfied: 0.099 < fw / f1 < 0.149, and -0.888 < fw / f2 < -0.592, and 0.169 < fw / f3 < 0.253, and 0.246 < fw / f4 < 0.369, and -0.1 < fw / f5 < 0.

1.

2. The zoom optical system according to claim 1, characterized in that, the first lens group includes a first lens, a second lens, a third lens and a fourth lens successively arranged from the object side to the image side; the second lens group includes a fifth lens, a sixth lens and a seventh lens successively arranged from the object side to the image side; the third lens group includes an eighth lens, a ninth lens, a tenth lens and an eleventh lens successively arranged from the object side to the image side; the fourth lens group includes a twelfth lens, a thirteenth lens and a fourteenth lens successively arranged from the object side to the image side; the fifth lens group includes a fifteenth lens.

3. The zoom optical system according to claim 2, characterized in that, the first lens has a negative optical power, the second lens has a positive optical power, the third lens has a positive optical power, and the fourth lens has a positive optical power; wherein, 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, and the focal length of the fourth lens is f14; in each lens of the first lens group, the following conditions are satisfied: -0.806 < f1 / f11 < -0.537, and 0.547 < f1 / f12 < 0.821, and 0.446 < f1 / f13 < 0.67, and 0.387 < f1 / f14 < 0.

581.

4. The zoom optical system according to claim 2, characterized in that, the fifth lens has a negative optical power, the sixth lens has a negative optical power, and the seventh lens has a positive optical power; wherein, the focal length of the fifth lens is f21, the focal length of the sixth lens is f22, and the focal length of the seventh lens is f23; in each lens of the second lens group, the following conditions are satisfied: 0.617 < f2 / f21 < 0.925, and 0.504 < f2 / f22 < 0.757, and -0.511 < f2 / f23 < -0.

341.

5. The zoom optical system according to claim 2, characterized in that the eighth lens has a positive optical power, the ninth lens has an aggregated positive optical power, the tenth lens has a negative optical power, and the eleventh lens has a negative optical power; wherein, the focal length of the eighth lens is f31, the focal length of the ninth lens is f32, the focal length of the tenth lens is f33, and the focal length of the eleventh lens is f34; each lens in the third lens group satisfies the following conditions: 1.105 < f3 / f31 < 1.658, and 0.444 < f3 / f32 < 0.665, and -0.39 < f3 / f33 < -0.26, and -1.26 < f3 / f34 < -0.

84.

6. The zoom optical system according to claim 2, characterized in that the twelfth lens has a positive optical power, the thirteenth lens has a negative optical power, and the fourteenth lens has a positive optical power; wherein, the focal length of the twelfth lens is f41, the focal length of the thirteenth lens is f42, and the focal length of the fourteenth lens is f43; each lens in the fourth lens group satisfies the following conditions: 0.404 < f4 / f41 < 0.606, and -0.722 < f4 / f42 < -0.482, and 0.931 < f4 / f43 < 1.

396.

7. The zoom optical system according to claim 2, characterized in that the zoom optical system satisfies the following conditions: 0.279 < ΔZW-T / TTL < 0.362; wherein, ΔZW-T is the relative displacement amount of the fourth lens 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.

8. The zoom optical system according to claim 2, characterized in that the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the eighth lens, the ninth lens, the eleventh lens, the thirteenth lens, and the fourteenth lens are glass material lenses; the sixth lens, the seventh lens, the tenth lens, the twelfth lens, and the fifteenth lens are plastic aspherical lenses.

9. The zoom optical system according to claim 1, characterized in that the zoom optical system further includes a diaphragm, and the diaphragm is located between the second lens group and the third lens group; the zoom optical system satisfies the following conditions: 0.337 < L / TTL < 0.456; wherein, L is the distance from the diaphragm to the imaging surface of the zoom optical system on the optical axis, and TTL is the overall optical length of the zoom optical system.

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

Images