Zoom optical system

Abstract

The invention discloses a zoom optical system, and relates to the technical field of zoom optical systems.The zoom optical system is provided with an object side and an image side which are correspondingly arranged in the optical axis direction, and the zoom optical system comprises a first lens set, a second lens set, a third lens set, a fourth lens set, a fifth lens set and an image plane which are sequentially arranged from the object side to the image side; the second lens group, the fourth lens group and the fifth lens group are all movably arranged along the optical axis direction, the moving stroke of the second lens group is 26.2 mm, the moving stroke of the fourth lens group is 5.8 mm, the moving stroke of the fifth lens group is 1.07 mm, the second lens group and the fifth lens group are used for zooming, and the fourth lens group is used for focusing. Through the arrangement, the optical distortion range of the zoom optical system can be between-4.04% and 2.94%. Therefore, the optical zoom system which is small in size, small in distortion, short in focusing object distance and confocal at high and low temperatures is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of zoom optical systems, and in particular to a zoom optical system. Background Art

[0002] In the field of video applications (film and broadcasting), zoom lenses have been widely used due to their advantages such as clear shooting images, short shooting distance, large shooting angle and small distortion. With the development of technology, high pixels, large target area, small distortion and close object distance imaging have become requirements for the new generation of video lenses.

[0003] However, the mainstream video zoom lenses currently on the market have problems such as low clarity, large size, unclear focusing at close object distances, and small target surface of the photosensitive chip, and are increasingly unable to meet market demand. Summary of the invention

[0004] The main purpose of the present invention is to provide a zoom optical system, aiming to solve the problems of existing video zoom lenses, such as low clarity, large size, unclear focusing at close object distances, and small target surface of photosensitive chips, which are increasingly unable to meet market demand.

[0005] To achieve the above-mentioned object, the zoom optical system proposed in the present invention has an object side and an image side correspondingly arranged along the optical axis direction, the zoom optical system comprises a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group and an image plane arranged in sequence from the object side to the image side, the second lens group, the fourth lens group and the fifth lens group are all movably arranged along the optical axis direction, the movable stroke of the second lens group is 26.2 mm, the movable stroke of the fourth lens group is 5.8 mm, and the movable stroke of the fifth lens group is 1.07 mm, the second lens group and the fifth lens group are used for zooming, and the fourth lens group is used for focusing;

[0006] The focal length of the zoom optical system is f, 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. The zoom optical system meets the following conditions:

[0007] 20.8mm≤f≤59.17mm; 0.260≤fw / f1≤0.302; and -1.330≤fw / f2≤-0.983; and 0.867≤fw / f3≤1.174; and -1.286≤fw / f4≤-0.950; and 0.398≤fw / f5≤0.539.

[0008] In one embodiment, the optical power of the first lens group is positive, and the first lens group includes a first lens with negative optical power, a second lens with positive optical power, and a third lens with positive optical power, which are arranged in sequence along the optical axis, and the first lens and the second lens are glued together;

[0009] The focal length of the first lens is f11, the focal length of the second lens is f12, and the focal length of the third lens is f13, wherein -0.664≤f1 / f11≤-0.573; and 0.729≤f1 / f12≤0.845; and 0.706≤f1 / f13≤0.819.

[0010] In one embodiment, the optical power of the second lens group is negative, and the second lens group includes a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with negative optical power, which are arranged in sequence along the optical axis, and the fifth lens and the sixth lens are cemented together;

[0011] The focal length of the fourth lens is f21, the focal length of the fifth lens is f22, and the focal length of the sixth lens is f23, wherein 0.664≤f2 / f21≤0.898; and 0.643≤f2 / f22≤0.870; and -0.705≤f2 / f23≤-0.521.

[0012] In one embodiment, the third lens group has a positive optical power, and comprises a seventh lens with a positive optical power, an eighth lens with a positive optical power, a ninth lens with a negative optical power, and a tenth lens with a positive optical power, which are sequentially arranged along the optical axis direction, the seventh lens is a plastic aspherical lens, and the ninth lens and the tenth lens are glued together;

[0013] The focal length of the seventh lens is f31, the focal length of the eighth lens is f32, the focal length of the ninth lens is f33, and the focal length of the tenth lens is f34, wherein 0.479≤f3 / f31≤0.648; and 0.610≤f3 / f32≤0.825; and -1.587≤f3 / f33≤-1.173; and 1.048≤f3 / f34≤1.418.

[0014] In one embodiment, the fourth lens group has a negative optical power, and includes an eleventh lens with a positive optical power and a twelfth lens with a positive optical power, which are sequentially arranged along the optical axis, and the twelfth lens is a plastic aspherical lens;

[0015] The focal length of the eleventh lens is f41, and the focal length of the twelfth lens is f42, wherein 0.249≤f4 / f41≤0.337; and 0.569≤f4 / f42≤0.770.

[0016] In one embodiment, the fifth lens group has a positive optical power, and comprises a thirteenth lens with a positive optical power, a fourteenth lens with a negative optical power, and a fifteenth lens with a negative optical power, which are sequentially arranged along the optical axis, and the thirteenth lens and the fifteenth lens are cemented together;

[0017] The focal length of the thirteenth lens is f51, the focal length of the fourteenth lens is f52, and the focal length of the fifteenth lens is f53, wherein 1.491≤f5 / f51≤2.017; and -0.282≤f5 / f51≤-0.209; and -0.699≤f5 / f51≤-0.517.

[0018] In one implementation, the total optical length of the zoom optical system is TTL, and TTL≤123.7 mm.

[0019] In one implementation, the aperture of the zoom optical system is Fno, 2.82≤Fno≤4.08.

[0020] In one embodiment, the image plane size of the zoom optical system is

[0021] In one embodiment, the zoom optical system further includes an aperture and a filter, wherein the aperture is disposed between the second lens group and the third lens group, and the filter is disposed between the fifth lens group and the image plane.

[0022] In the technical solution of the present invention, the first lens group and the third lens group are both fixed lens groups, the second lens group and the fifth lens group are both movably arranged along the optical axis direction to zoom the zoom optical system, and the fourth lens group is cooperatively arranged along the optical axis direction to focus the zoom optical system, so that the zoom optical system can keep the image of the image plane clear during the zooming process. In this way, the zoom function of the zoom optical system is ensured by setting the movable stroke of the second lens group, the fourth lens group and the fifth lens group. At the same time, the optical distortion range of the zoom optical system is between -4.04% and 2.94% through the conditional restriction of the ratio of the focal length of the five lens groups to the focal length of the zoom optical system at the wide-angle end and the restriction of the angle range of the zoom optical system. Thus, an optical zoom system with small size, small distortion, close focus object distance and high and low temperature confocal is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0024] Figure 1 A schematic structural diagram of an embodiment of a zoom optical system (wide-angle end) provided by the present invention;

[0025] Figure 2 A schematic structural diagram of an embodiment of a zoom optical system (intermediate magnification) provided by the present invention;

[0026] Figure 3 A schematic structural diagram of an embodiment of a zoom optical system (telephoto end) provided by the present invention;

[0027] Figure 4 is a schematic diagram of MTF when the zoom optical system is at a wide-angle end;

[0028] Figure 5 is a schematic diagram of MTF when the zoom optical system is at an intermediate magnification;

[0029] Figure 6 is a schematic diagram of MTF when the zoom optical system is at the telephoto end;

[0030] Figure 7 is a schematic diagram of FCD when the zoom optical system is at a wide-angle end;

[0031] Figure 8 is a schematic diagram of FCD when the zoom optical system is at an intermediate magnification;

[0032] Fig. 9 is a schematic diagram of FCD when the zoom optical system is at a telephoto end;

[0033] Fig.10 is a schematic diagram of LON when the zoom optical system is at a wide-angle end;

[0034] Fig.11 is a schematic diagram of LON when the zoom optical system is at an intermediate magnification;

[0035] Fig.12 is a schematic diagram of LON when the zoom optical system is at a telephoto end;

[0036] Fig.13 is a schematic diagram of LAT when the zoom optical system is at a wide-angle end;

[0037] Fig.14is a schematic diagram of LAT when the zoom optical system is at an intermediate magnification;

[0038] Fig.15 Schematic diagram of LAT when the zoom optical system is at the telephoto end.

[0039] Description of Figure Numbers:

[0040] 100. Zoom optical system; 1. First lens group; 11. First lens; 12. Second lens; 13. Third lens; 2. Second lens group; 21. Fourth lens; 22. Fifth lens; 23. Sixth lens; 3. Third lens group; 31. Seventh lens; 32. Eighth lens; 33. Ninth lens; 34. Tenth lens; 4. Fourth lens group; 41. Eleventh lens; 42. Twelfth lens; 5. Fifth lens group; 51. Thirteenth lens; 52. Fourteenth lens; 53. Fifteenth lens; 6. Image plane; 7. Diaphragm; 8. Filter.

[0041] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0043] 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 in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0044] 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 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 limited to "first" and "second" may explicitly or implicitly include at least one of the 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 contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] The present invention provides a zoom optical system, which aims to solve the problems of existing video zoom lenses, such as low definition, large size, unclear focusing at close object distances, and small target surface of photosensitive chips, which are increasingly unable to meet market demands.

[0046] See also Figure 1-3 In one embodiment of the present invention, the zoom optical system 100 has an object side and an image side correspondingly arranged along the optical axis direction. The zoom optical system 100 includes a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4, a fifth lens group 5 and an image plane 6 arranged in sequence from the object side to the image side. The second lens group 2, the fourth lens group 4 and the fifth lens group 5 are all movably arranged along the optical axis direction. The movable stroke of the second lens group 2 is 26.2 mm, the movable stroke of the fourth lens group 4 is 5.8 mm, and the movable stroke of the fifth lens group 5 is 1.07 mm. The second lens group 2 and the fifth lens group 5 are used for zooming, and the fourth lens group 4 is used for focusing. The zoom optical system 100 0 is f, the focal length of the zoom optical system 100 at the wide-angle end is fw, the focal length of the first lens group 1 is f1, the focal length of the second lens group 2 is f2, the focal length of the third lens group 3 is f3, the focal length of the fourth lens group 4 is f4, and the focal length of the fifth lens group 5 is f5, and the zoom optical system 100 satisfies the following conditions: 20.8mm≤f≤59.17mm; 0.260≤fw / f1≤0.302; and -1.330≤fw / f2≤-0.983; and 0.867≤fw / f3≤1.174; and -1.286≤fw / f4≤-0.950; and 0.398≤fw / f5≤0.539.

[0047] In the technical solution of the present invention, the first lens group 1 and the third lens group 3 are both fixed lens groups, the second lens group 2 and the fifth lens group 5 are both movably arranged along the optical axis direction to zoom the zoom optical system 100, and the fourth lens group 4 is cooperatively movable along the optical axis direction to focus the zoom optical system 100, so that the zoom optical system 100 can keep the image of the image plane 6 clear during the zooming process. In this way, the zoom function of the zoom optical system 100 is ensured by setting the movable strokes of the second lens group 2, the fourth lens group 4 and the fifth lens group 5. At the same time, the optical distortion range of the zoom optical system 100 is between -4.04% and 2.94% through the conditional restriction of the ratio of the focal length of the five lens groups to the focal length of the zoom optical system 100 at the wide-angle end and the restriction of the angle range of the zoom optical system 100. Thus, an optical zoom system with small size, small distortion, close focus object distance and high and low temperature confocal is obtained.

[0048] It should be noted that, in the present invention, the total optical length TTL of the zoom optical system 100 can be controlled within 123.7 mm, that is, TTL≤123.7 mm.

[0049] In addition, the displacement of the second lens group 2 is ΔZ1(WT), the displacement of the fourth lens group 4 is ΔZ2(WT), and the displacement of the objective lens group is ΔZ3(WT), wherein 0.184<ΔZ1(WT) / TTL<0.239; and 0.008<ΔZ2(WT) / TTL<0.01; and 0.047<ΔF(WT) / TTL<0.053.

[0050] The present invention does not limit the specific values ​​of the displacements of the second lens group 2, the fourth lens group 4 and the fifth lens group 5. It only needs to ensure that the displacements of the second lens group 2, the fourth lens group 4 and the fifth lens group 5 are any values ​​within a range.

[0051] It can be understood that the present invention does not limit the specific driving form of the second lens group 2, the fourth lens group 4 and the fifth lens group 5 moving along the optical axis. In one embodiment of the present invention, the second lens group 2, the fourth lens group 4 and the fifth lens group 5 can be driven by a driving motor to move along the optical axis. Specifically, in this embodiment, the output end of the driving motor drives the ball nut connected to the screw structure, and a plurality of ball nuts are movably provided on the screw of the screw structure. The second lens group 2, the fourth lens group 4 and the fifth lens group 5 are respectively movably connected to one of the ball nut settings. With this arrangement, when it is necessary to adjust the position of one of the lens groups, the corresponding ball nut of the screw structure is driven to rotate.

[0052] In another embodiment of the present invention, the second lens group 2, the fourth lens group 4 and the fifth lens group 5 can be adjusted manually, and the present invention does not limit this. In actual settings, they can be selected according to needs.

[0053] Of course, it can be understood that in the present invention, the optical focal length of the first lens group 1 is positive, and the first lens group 1 includes a first lens 11 with a negative optical focal length, a second lens 12 with a positive optical focal length, and a third lens 13 with a positive optical focal length, which are arranged in sequence along the optical axis.

[0054] In a specific embodiment of the present invention, the focal length of the first lens 11 is f11, the focal length of the second lens 12 is f12, and the focal length of the third lens 13 is f13, wherein -0.664≤f1 / f11≤-0.573; and 0.729≤f1 / f12≤0.845; and 0.706≤f1 / f13≤0.819.

[0055] It can be understood that the present invention does not limit the specific values ​​of the focal lengths of the first lens 11, the second lens 12 and the third lens 13. In an embodiment of the present invention, the first lens 11, the second lens 12 and the third lens 13 can be set to any value within a range.

[0056] Moreover, in this embodiment, the first lens 11 and the second lens 12 are glued together. Such a configuration can better correct the chromatic aberration of the zoom optical system 100. At the same time, the glued connection can also reduce the loss of light energy, increase the imaging clarity, and protect the scale surface, thereby further optimizing the processing flow to meet the design requirements. Therefore, the glued parts are used reasonably to allow optical components to improve the image quality of the optical system.

[0057] It should also be noted that in this embodiment, the aperture of the first lens 11 is and

[0058] In another embodiment of the present invention, the optical power of the second lens group 2 is negative. The second lens group 2 includes a fourth lens 21 with positive optical power, a fifth lens 22 with positive optical power, and a sixth lens 23 with negative optical power, which are sequentially arranged along the optical axis direction. The focal length of the fourth lens 21 is f21, the focal length of the fifth lens 22 is f22, and the focal length of the sixth lens 23 is f23, wherein 0.664≤f2 / f21≤0.898; and 0.643≤f2 / f22≤0.870; and -0.705≤f2 / f23≤-0.521.

[0059] Similarly, in this embodiment, the specific values ​​of the focal lengths of the first lens 11, the second lens 12 and the third lens 13 may also be set to any value within a range, and the present invention does not impose any limitation on this.

[0060] It should also be noted that, in a further embodiment of the present invention, the fifth lens 22 and the sixth lens 23 are glued together to further correct the chromatic aberration of the zoom optical system 100 and reduce the light energy loss.

[0061] In another embodiment of the present invention, the third lens group 3 has a positive focal power, and comprises a seventh lens 31 with a positive focal power, an eighth lens 32 with a positive focal power, a ninth lens 33 with a negative focal power, and a tenth lens 34 with a positive focal power, which are sequentially arranged along the optical axis direction. The seventh lens 31 is a plastic aspherical lens, the focal length of the seventh lens 31 is f31, the focal length of the eighth lens 32 is f32, the focal length of the ninth lens 33 is f33, and the focal length of the tenth lens 34 is f34, wherein 0.479≤f3 / f31≤0.648; and 0.610≤f3 / f32≤0.825; and -1.587≤f3 / f33≤-1.173; and 1.048≤f3 / f34≤1.418.

[0062] Of course, in the present invention, the specific values ​​of the seventh lens 31, the eighth lens 32, the ninth lens 33 and the tenth lens 34 only need to be any value within the range, and the present invention does not limit this.

[0063] Meanwhile, in this embodiment, the seventh lens 31 is configured as a plastic lens, so as to further reduce the manufacturing cost of the zoom optical system 100. In addition, the seventh lens 31 is configured as an aspherical lens, and the curvature of the aspherical lens changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens having a constant curvature from the center of the lens to the periphery of the lens, the aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After using the aspherical lens, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens.

[0064] In addition, in another embodiment of the present invention, the fourth lens group 4 has a negative optical focal length, and the fourth lens group 4 includes an eleventh lens 41 with a positive optical focal length and a twelfth lens 42 with a positive optical focal length, which are sequentially arranged along the optical axis direction. The focal length of the eleventh lens 41 is f41, and the focal length of the twelfth lens 42 is f42, wherein 0.249≤f4 / f41≤0.337; and 0.569≤f4 / f42≤0.770.

[0065] It can be understood that the present invention does not limit the specific values ​​of the eleventh lens 41 and the twelfth lens 42. In actual settings, the specific values ​​of the eleventh lens 41 and the twelfth lens 42 only need to be any value within the range, and the present invention does not impose any limitation.

[0066] Likewise, in this embodiment, the twelfth lens 42 is also configured as a plastic aspherical lens, so as to further reduce the manufacturing cost of the zoom optical system 100 while improving the imaging quality of the lens.

[0067] In still another embodiment of the present invention, the fifth lens group 5 has positive focal power, and comprises a thirteenth lens 51 with positive focal power, a fourteenth lens 52 with negative focal power, and a fifteenth lens 53 with negative focal power, which are sequentially arranged along the optical axis direction, the focal length of the thirteenth lens 51 is f51, the focal length of the fourteenth lens 52 is f52, and the focal length of the fifteenth lens 53 is f53, wherein 1.491≤f5 / f51≤2.017; and -0.282≤f5 / f51≤-0.209; and -0.699≤f5 / f51≤-0.517.

[0068] Of course, the present invention also does not limit the specific values ​​of the thirteenth lens 51, the fourteenth lens 52 and the fifteenth lens 53. In actual settings, the specific values ​​of the eleventh lens 41 and the twelfth lens 42 only need to be selected as any value within the range, and the present invention does not impose any limitation.

[0069] Moreover, in this embodiment, the fourteenth lens 52 and the fifteenth lens 53 are glued together, so as to better correct the chromatic aberration of the zoom optical system 100. At the same time, the gluing connection can also reduce the loss of light energy, increase the imaging clarity, and protect the scale surface, thereby further optimizing the processing flow to meet the design requirements, so that the optical components can improve the image quality of the optical system.

[0070] In an embodiment of the present invention, the aperture of the zoom optical system 100 is Fno, 2.82≤Fno≤4.08. In this way, the zoom optical system 100 has a large aperture characteristic, so that the zoom optical system 100 can still have excellent imaging effects in a low-light environment.

[0071] Furthermore, in another embodiment of the present invention, the size of the image plane 6 of the zoom optical system 100 is φ, φ≤25.8 mm. This arrangement can ensure that the imaging of the zoom optical system 100 is complete.

[0072] It should also be noted that, in an embodiment of the present invention, the zoom optical system 100 further includes an aperture 7 and a filter 8, the aperture 7 is arranged between the second lens group 2 and the third lens group 3, the filter 8 is arranged on the side of the fourth lens group 4 facing the image side, and the aperture 7 is used to adjust the light flux according to actual conditions to improve the imaging quality.

[0073] It should be noted that the distance between the aperture 7 and the image plane 6 is L, L≤61.3 mm, and 0.431 <L / TTL<0.560。

[0074] In addition, in the above-mentioned multiple embodiments, the first lens 11, the second lens 12, the third lens 13, the fourth lens 21, the fifth lens 22, the sixth lens 23, the eighth lens 32, the ninth lens 33, the tenth lens 34, the eleventh lens 41, the thirteenth lens 51, the fourteenth lens 52 and the fifteenth lens 53 can all be set as glass lenses. In this way, the use of lenses made of glass can reduce the influence of temperature on the optical properties of the lens. The glass lens is not easily affected by thermal expansion and contraction and has a focus deviation phenomenon. Therefore, the glass lens can well resist the problem of thermal deformation of the lens and maintain the high precision of the lens for a long time. The setting of the filter 8 can effectively filter out stray light in non-working bands to reduce optical noise, reduce difficulties for the subsequent optoelectronic module processing part, and thus improve imaging quality.

[0075] Specifically, in a specific embodiment of the present invention, the surface type, curvature radius, thickness, material refractive index and material Abbe number of the lens in this embodiment are shown in Table 1 below:

[0076] Table 1

[0077]

[0078]

[0079] It should be noted that, in this embodiment, And ΔZ1(WT) / TTL=0.212; and ΔZ2(WT) / TTL=0.009; and ΔF(WT) / TTL=0.041; and L / TTL=0.495.

[0080] Specifically, the surface shape z of each aspheric lens can be defined by but not limited to the following aspheric formula:

[0081]

[0082] Among them, c is the curvature corresponding to the radius, y is the radial coordinate (its unit is the same as the lens length unit), k is the 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, E, F, G, H are high-order aspheric coefficients, and the high-order coefficients of each aspheric mirror surface can be seen from the following Table 2:

[0083] Table 2 Conic coefficients and aspheric coefficients corresponding to aspheric lenses

[0084]

[0085]

[0086] With this setting, by reasonably allocating the lens power, adjusting the glass shape and material combination, effectively eliminating chromatic aberration and secondary spectrum, the spherical aberration, coma, astigmatism, etc. on each lens compensate and cancel each other out, so as to achieve a clear imaging effect and realize the optimal correction of high-order aberrations and chromatic aberrations.

[0087] Figure 4-6 Schematic diagram of the MTF of the zoom optical system 100 of the present invention at the wide-angle end, the intermediate magnification and the telephoto end; Figure 7-9 Schematic diagram of FCD of the zoom optical system 100 of the present invention at a wide-angle end, an intermediate magnification, and a telephoto end; Figure 10-12 Schematic diagram of LON of the zoom optical system 100 of the present invention at a wide-angle end, an intermediate magnification, and a telephoto end; Figure 13-15 Schematic diagram of LAT of the zoom optical system 100 of the present invention at a wide-angle end, an intermediate magnification, and a telephoto end.

[0088] It should be noted that Table 2 is a design value of the aspheric coefficient of the lens in the zoom optical system 100 described in this embodiment. The specific numerical value of the aspheric coefficient design value can be adjusted according to product requirements, and the present invention does not limit this.

[0089] In addition, the intervals between the lens groups of the zoom optical system 100 in this embodiment from the Wide end (wide-angle end) to the Tele end (telephoto end) are changed as follows:

[0090] Table 3

[0091] Wide Angle Intermediate magnification Telephoto Focal length / mm 20.8 30.23 59.17 Fno aperture 2.82 3.89 4.08 T(10) 31.080 20.510 4.910 T(22) 9.910 6.220 3.030 T(27) 5.300 6.540 6.370

[0092] The above description is only an exemplary 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 technical 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 correspondingly arranged along the optical axis direction, and comprises a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group and an image plane arranged in sequence from the object side to the image side, the second lens group, the fourth lens group and the fifth lens group are all movably arranged along the optical axis direction, the movable stroke of the second lens group is 26.2 mm, the movable stroke of the fourth lens group is 5.8 mm, and the movable stroke of the fifth lens group is 1.07 mm, the second lens group and the fifth lens group are used for zooming, and the fourth lens group is used for focusing; The focal length of the zoom optical system is f, 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. The zoom optical system meets the following conditions: 20.8mm≤f≤59.17mm; 0.260≤fw / f1≤0.302; and -1.330≤fw / f2≤-0.983; and 0.867≤fw / f3≤1.174; and -1.286≤fw / f4≤-0.950; and 0.398≤fw / f5≤0.

539.

2. The zoom optical system according to claim 1, wherein: The optical power of the first lens group is positive, and the first lens group comprises a first lens with negative optical power, a second lens with positive optical power, and a third lens with positive optical power, which are arranged in sequence along the optical axis, and the first lens and the second lens are glued together; The focal length of the first lens is f11, the focal length of the second lens is f12, and the focal length of the third lens is f13, wherein -0.664≤f1 / f11≤-0.573; and 0.729≤f1 / f12≤0.845; and 0.706≤f1 / f13≤0.

819.

3. The zoom optical system according to claim 1, wherein: The optical power of the second lens group is negative, and the second lens group comprises a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with negative optical power, which are arranged in sequence along the optical axis, and the fifth lens and the sixth lens are glued together; The focal length of the fourth lens is f21, the focal length of the fifth lens is f22, and the focal length of the sixth lens is f23, wherein 0.664≤f2 / f21≤0.898; and 0.643≤f2 / f22≤0.870; and -0.705≤f2 / f23≤-0.

521.

4. The zoom optical system according to claim 1, wherein: The third lens group has a positive optical power, and comprises a seventh lens with a positive optical power, an eighth lens with a positive optical power, a ninth lens with a negative optical power, and a tenth lens with a positive optical power, which are sequentially arranged along the optical axis direction, the seventh lens is a plastic aspherical lens, and the ninth lens and the tenth lens are glued together; The focal length of the seventh lens is f31, the focal length of the eighth lens is f32, the focal length of the ninth lens is f33, and the focal length of the tenth lens is f34, wherein 0.479≤f3 / f31≤0.648; and 0.610≤f3 / f32≤0.825; and -1.587≤f3 / f33≤-1.173; and 1.048≤f3 / f34≤1.

418.

5. The zoom optical system according to claim 1, wherein: The fourth lens group has a negative optical power, and comprises an eleventh lens with a positive optical power and a twelfth lens with a positive optical power, which are sequentially arranged along the optical axis, and the twelfth lens is a plastic aspherical lens; The focal length of the eleventh lens is f41, and the focal length of the twelfth lens is f42, wherein 0.249≤f4 / f41≤0.337; and 0.569≤f4 / f42≤0.

770.

6. The zoom optical system according to claim 1, wherein: The optical power of the fifth lens group is positive, and the fifth lens group includes a thirteenth lens with positive optical power, a fourteenth lens with negative optical power, and a fifteenth lens with negative optical power, which are sequentially arranged along the optical axis direction, and the thirteenth lens and the fifteenth lens are cemented together; The focal length of the thirteenth lens is f51, the focal length of the fourteenth lens is f52, and the focal length of the fifteenth lens is f53, wherein 1.491≤f5 / f51≤2.017; and -0.282≤f5 / f51≤-0.209; and -0.699≤f5 / f51≤-0.

517.

7. The zoom optical system according to claim 1, wherein: The total optical length of the zoom optical system is TTL, and TTL≤123.7 mm.

8. The zoom optical system according to claim 1, wherein: The aperture of the zoom optical system is Fno, 2.82≤Fno≤4.

08.

9. The zoom optical system according to claim 1, wherein: The image plane size of the zoom optical system is φ, φ≤25.8 mm.

10. The zoom optical system according to claim 1, wherein: The zoom optical system further includes an aperture and a filter, wherein the aperture is arranged between the second lens group and the third lens group, and the filter is arranged between the fifth lens group and the image plane.

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