Zoom optical system
By designing the lens group in the zoom optical system to reasonably control the optical power and displacement, the performance defects of existing high-magnification zoom lenses have been solved, achieving small size, large zoom, low distortion and close focusing distance, thus improving image quality.
Patent Information
- Application Number
- CN202511637546.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-10
- Publication Date
- 2026-03-03
AI Technical Summary
Existing high-magnification zoom lenses suffer from problems such as insufficient wide-angle angle, insufficient magnification at the telephoto end, insufficient focusing distance range, small aperture, and insufficient resolution, which limit their application scenarios and result in low image quality.
Design a zoom optical system comprising a first lens group, a second lens group, a third lens group, and a fourth lens group arranged sequentially from the object side to the image side. The second and third lens groups move along the optical axis to zoom, and the fourth lens group is used for focusing. The focal length and displacement of the lens groups are precisely controlled, and the total optical length is controlled within 60.1 mm. The lens groups are reasonably matched with optical power to achieve the effects of small size, large magnification, small distortion, and close focusing distance.
It achieves the effects of small size, large zoom, low distortion and close focusing distance in zoom optical system, improves image clarity and resolution, and adapts to imaging needs in a variety of environments.
Smart Images
Figure CN121596524A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optical system technology, and in particular to a zoom optical system. Background Technology
[0002] With the development of chip technologies such as CCD and CMOS, and the increasing demands for video image quality, the requirements for the imaging quality of the corresponding optical systems are also becoming higher. To meet this trend, optical lenses mounted on video products are further required to have high resolution, high magnification, high definition even at close range, wide shooting angle, low distortion, and small size.
[0003] However, existing high-magnification zoom lenses still have some performance defects, which limit their application scenarios. For example, the wide-angle end is not wide enough, resulting in a limited shooting range; the telephoto end has insufficient magnification, resulting in insufficient magnification; the focusing distance range is not wide enough, resulting in limited application scenarios; the aperture is small, which cannot meet the shooting needs in low-light environments; and the resolution is insufficient, resulting in low resolution, etc. Summary of the Invention
[0004] The main objective of this invention is to propose a zoom optical system that aims to improve upon the problems existing in current zoom lenses.
[0005] To achieve the above objectives, the zoom optical system proposed in this invention has an object side and an image side arranged correspondingly along the optical axis. The zoom optical system includes a first lens group, a second lens group, a third lens group, a fourth lens group, and an image plane arranged sequentially from the object side to the image side. The second lens group, the third lens group, and the fourth lens group are all movable along the optical axis. The second lens group and the third lens group are used for zooming, and the fourth lens group is used for focusing. The total optical length of the zoom optical system is controlled within 60.1 mm. Wherein, the focal length of the zoom optical system at the wide-angle end is fw, the focal length at the telephoto end is ft, 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, and the focal length of the fourth lens group is f4. The zoom optical system satisfies the following conditions: fw = 4.85 mm; and ft = 72.04 mm; and 0.131 ≤ fw / f1 ≤ 0.177; and -0.796 ≤ fw / f2 ≤ -0.588; and 0.291 ≤ fw / f3 ≤ 0.394; and 0.240 ≤ fw / f4 ≤ 325.
[0006] In one embodiment, the optical power of the first lens group is positive; The optical power of the second lens group is negative; The optical power of the third lens group is positive; The optical power of the fourth lens group is positive.
[0007] In one embodiment, the first lens group includes a first lens, a second lens, and a third lens arranged sequentially from the object side to the image side. The first lens has a negative optical power, the second lens has a positive optical power, and the third lens has a positive optical power. The first lens and the second lens are cemented 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 -0.699≤f1 / f11≤-0.517; and 0.689≤f1 / f12≤0.932; and 0.723≤f1 / f13≤0.978.
[0008] In one embodiment, the second lens group includes a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side, wherein the optical power of the fourth lens is negative, the optical power of the fifth lens is negative, and the optical power of the sixth lens is positive. 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 0.778≤f2 / f21≤1.053; and 0.438≤f2 / f22≤0.539; and -0.509≤f2 / f23≤-0.376.
[0009] In one embodiment, the third lens group includes a seventh lens, an eighth lens, and a ninth lens arranged sequentially from the object side to the image side. The seventh lens has a positive optical power, the eighth lens has a positive optical power, and the ninth lens has a negative optical power. The seventh lens is configured as an aspherical lens. The focal length of the seventh lens is f31, the focal length of the eighth lens is f32, and the focal length of the ninth lens is f33, wherein 1.350≤f3 / f31≤1.827; and 0.752≤f3 / f32≤1.017; and -2.754≤f3 / f33≤-2.036.
[0010] In one embodiment, the fourth lens group includes a tenth lens and an eleventh lens arranged sequentially from the object side to the image side, wherein the optical power of the tenth lens is negative and the optical power of the eleventh lens is positive. The focal length of the tenth lens is f41, and the focal length of the eleventh lens is f42, wherein -0.624≤f4 / f41≤-0.461; and 1.307≤f4 / f42≤1.768.
[0011] In one embodiment, the total optical length of the zoom optical system is TTL, the first lens group includes a first lens, the first lens is disposed close to the object side, and the aperture of the first lens is øL11, 0.383<øL11 / TTL<0.497.
[0012] In one embodiment, the total optical length of the zoom optical system is TTL, the displacement of the second lens group is ΔZ1(WT), 0.281 < ΔZ1(WT) / TTL < 0.365; and / or, The total optical length of the zoom optical system is TTL, and the displacement of the third lens group is ΔZ2(WT), where 0.07 < ΔZ2(WT) / TTL < 0.091; and / or, The total optical length of the zoom optical system is TTL, and the displacement of the fourth lens group is ΔF(WT), where 0.055 < ΔF(WT) / TTL < 0.072.
[0013] In one embodiment, the zoom optical system further includes an aperture stop disposed between the second lens group and the third lens group. The distance between the aperture stop and the image plane is L, and the total optical length of the zoom optical system is TTL, 0.297. <L / TTL<0.385。
[0014] In one embodiment, the zoom optical system further includes a filter disposed between the fourth lens group and the image plane.
[0015] In the technical solution of this invention, the first lens group is set as a fixed lens group, the second lens group and the third lens group are movable along the optical axis to zoom the zoom optical system, and the fourth lens group moves in coordination along the optical axis to focus the zoom optical system, so that the zoom optical system maintains clear imaging of the image plane during the zooming process. In this way, the ratio of the focal length of the four lens groups to the focal length of the standard adhesive optical system at the wide-angle end is conditionally limited to control the total optical length of the zoom optical system within 60.1mm and the focal length of the zoom optical system between 4.85mm and 72.04mm, so as to achieve the effect of small size, large magnification, small distortion and close focusing distance of the zoom optical system. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of an embodiment of the zoom optical system provided by the present invention at the wide-angle end; Figure 2 This is a schematic diagram of a mid-focal length embodiment of the zoom optical system provided by the present invention. Figure 3 This is a schematic diagram of a telephoto end embodiment of the zoom optical system provided by the present invention. Figure 4 A schematic diagram of the zoom optical system provided by the present invention with an MTF of 125 lp / mm; Figure 5 This is a schematic diagram of the MTF vs Field of the zoom optical system provided by the present invention; Figure 6 A schematic diagram of the zoom optical system provided by the present invention at 125 lp / mm (defocus MTF); Figure 7 A schematic diagram of the FCD for the zoom optical system provided by this invention; Figure 8 A schematic diagram of the zoom optical system provided by this invention; Figure 9 This is a schematic diagram of the LON of the zoom optical system provided by the present invention; Figure 10 This is a schematic diagram of the LAT of the zoom optical system provided by the present invention.
[0018] Explanation of icon numbers: 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; 4. Fourth lens group; 41. Tenth lens; 42. Eleventh lens; 5. Aperture stop; 6. Filter; 7. Image plane.
[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not 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 effort are within the scope of protection of the present invention.
[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0023] This invention proposes a zoom optical system designed to improve upon the problems existing in current zoom lenses.
[0024] Please see Figures 1 to 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. 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, and an image plane 7 arranged sequentially from the object side to the image side. The second lens group 2, the third lens group 3, and the fourth lens group 4 are all movable along the optical axis. The second lens group 2 and the third lens group 3 are used for zooming, and the fourth lens group 4 is used for focusing. The total optical length of the zoom optical system 100 is controlled within 60.1 mm. The focal length of the zoom optical system 100 at the wide-angle end is fw, and the focal length at the telephoto end is ft. The focal length of the first lens group 1 is f1, the focal length of the second lens group 2 is f2, the focal length of the third lens group 3 is f3, and the focal length of the fourth lens group 4 is f4. The zoom optical system 100 satisfies the following conditions: fw = 4.85 mm; and ft = 72.04 mm; and 0.131 ≤ fw / f1 ≤ 0.177; and -0.796 ≤ fw / f2 ≤ -0.588; and 0.291 ≤ fw / f3 ≤ 0.394; and 0.240 ≤ fw / f4 ≤ 325.
[0025] In the technical solution of the present invention, the first lens group 1 is set as a fixed lens group, the second lens group 2 and the third lens group 3 are movably arranged along the optical axis to zoom the zoom optical system 100, and the fourth lens group 21 moves in coordination along the optical axis to focus the zoom optical system 100, so that the zoom optical system 100 maintains clear imaging of the image plane 7 during the zooming process. In this way, the conditional limitation of the ratio of the focal length of the four lens groups to the focal length of the standard adhesive optical system at the wide-angle end controls the total optical length of the zoom optical system 100 to within 60.1mm, and controls the focal length of the zoom optical system 100 to between 4.85mm and 72.04mm, so as to achieve the effect of small volume, large magnification, small distortion and close focusing distance of the zoom optical system 100.
[0026] It is understood that this invention does not limit the specific movement of the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 along the optical axis. In one embodiment of this invention, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can be configured to be driven by a drive motor respectively, so as to realize the individual driving of the second mirror group 2, the third mirror group 3, and the fourth mirror group 4. In another embodiment of this invention, the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can also be configured to be driven by the same drive motor, with each mirror group connected to the drive shaft of the drive motor through a transmission connector. In this configuration, when the drive motor outputs driving force, the driving force of the drive motor can be transmitted to the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 respectively through multiple transmission connectors, thereby enabling the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 to achieve coordinated movement. In yet another embodiment of this invention, the driving force of the second mirror group 2, the third mirror group 3, and the fourth mirror group 4 can also be manually adjusted. This invention does not impose any restrictions here, and the appropriate method can be selected according to the actual requirements.
[0027] Similarly, it can be understood that in this invention, the optical power of the first lens group 1 is positive, the optical power of the second lens group 2 is negative, the optical power of the third lens group 3 is positive, and the optical power of the fourth lens group 4 is positive.
[0028] This configuration, through the coordination of multiple lens groups with appropriate optical power, ensures the imaging quality of the zoom optical system 100.
[0029] Specifically, in this invention, to achieve successful imaging of the zoom optical system 100, in one embodiment of this invention, the first lens group 1 includes a first lens 11, a second lens 12, and a third lens 13 arranged sequentially from the object side to the image side. The optical power of the first lens 11 is negative, the optical power of the second lens 12 is positive, and the optical power of the third lens 13 is positive. The first lens 11 and the second lens 12 are cemented together. 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 -0.699≤f1 / f11≤-0.517; and 0.689≤f1 / f12≤0.932; and 0.723≤f1 / f13≤0.978.
[0030] It is 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 the embodiments of the present invention, the first lens 11, the second lens 12 and the third lens 13 can be set to any value within the range.
[0031] For example, in one embodiment of the present invention, the focal length of the first lens 11 can be set to -54.36mm, the focal length of the second lens 12 can be set to 40.79mm, and the focal length of the third lens 13 can be set to 38.86mm. Thus, the focal length of the first lens group 1 is set to 32.3mm. In this embodiment, f1 / f11=-0.594, f1 / f12=0.792, and f1 / f13=0.831.
[0032] Furthermore, in this embodiment, the first lens 11 and the second lens 12 are cemented together. This arrangement can better correct the chromatic aberration of the zoom optical system 100. At the same time, the cemented connection can also reduce light energy loss, increase image clarity, and protect the scale surface, thereby further optimizing the processing flow to meet design requirements. Therefore, the reasonable use of cemented components can improve the image quality of the optical system.
[0033] Similarly, to achieve successful imaging of the zoom optical system 100, in another embodiment of the present invention, the second lens group 2 includes a fourth lens 21, a fifth lens 22, and a sixth lens 23 arranged sequentially from the object side to the image side. The optical power of the fourth lens 21 is negative, the optical power of the fifth lens 22 is negative, and the optical power of the sixth lens 23 is positive. 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 0.778≤f2 / f21≤1.053; and 0.438≤f2 / f22≤0.539; and -0.509≤f2 / f23≤-0.376.
[0034] Of course, in this invention, the specific values of the focal lengths of the fourth lens 21, the fifth lens 22, the sixth lens 23 and the seventh lens 31 can also be set to any value within the range, and this invention does not limit this.
[0035] For example, in a specific embodiment of the present invention, the focal length of the fourth lens 21 can be set to -8.01mm, the focal length of the fifth lens 22 can be set to -14.22mm, and the focal length of the sixth lens 23 can be set to 16.56mm. Thus, the focal length of the second lens group 2 is set to -7.17mm. In this embodiment, f2 / f21=0.895, f2 / f22=0.504, and f2 / f23=-0.433.
[0036] In another embodiment of the present invention, the third lens group 3 includes a seventh lens 31, an eighth lens 32, and a ninth lens 33 arranged sequentially from the object side to the image side. The optical power of the seventh lens 31 is positive, the optical power of the eighth lens 32 is positive, and the optical power of the ninth lens 33 is negative. The seventh lens 31 is configured as an aspherical lens, and the focal length of the seventh lens 31 is f31, the focal length of the eighth lens 32 is f32, and the focal length of the ninth lens 33 is f33.
[0037] Specifically, 1.350≤f3 / f31≤1.827; and 0.752≤f3 / f32≤1.017; and -2.754≤f3 / f33≤-2.036.
[0038] It is understood that the present invention does not limit the specific values of the focal lengths of the seventh lens 31, the eighth lens 32 and the ninth lens 33. In the embodiments of the present invention, the seventh lens 31, the eighth lens 32 and the ninth lens 33 can be set to any value within the range.
[0039] For example, in a specific embodiment of the present invention, the focal length of the seventh lens 31 can be set to 9.33 mm, the focal length of the eighth lens 32 can be set to 16.76 mm, and the focal length of the ninth lens 33 can be set to -6.19 mm. Thus, the focal length of the third lens group 3 is set to 14.49 mm. In this embodiment, f3 / f31=1.553, f3 / f32=0.865, and f3 / f33=-2.341.
[0040] It should also be noted that, in this embodiment, the seventh lens 31 can be configured as an aspherical lens. The characteristic of an aspherical lens is that the curvature changes continuously from the center of the lens to the periphery. Unlike a spherical lens, which has a constant curvature from the center of the lens to the periphery, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. By using an aspherical lens, aberrations that occur during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens.
[0041] In other embodiments of the present invention, the fourth lens group 4 includes a tenth lens 41 and an eleventh lens 42 arranged sequentially from the object side to the image side. The optical power of the tenth lens 41 is negative, and the optical power of the eleventh lens 42 is positive. The focal length of the tenth lens 41 is f41, and the focal length of the eleventh lens 42 is f42, wherein -0.624≤f4 / f41≤-0.461; and 1.307≤f4 / f42≤1.768.
[0042] Of course, the present invention does not limit the specific values of the focal lengths of the tenth lens 41 and the eleventh lens 42. In the embodiments of the present invention, the focal lengths of the tenth lens 41 and the eleventh lens 42 can be set to any value within the range.
[0043] In a specific embodiment of the present invention, the focal length of the tenth lens 41 can be set to -33.14mm, the focal length of the eleventh lens 42 can be set to 11.69mm, and thus the focal length of the fourth lens group 4 is set to 17.57mm. In this embodiment, f4 / f41=-0.530, f4 / f42=1.503.
[0044] To further improve the imaging clarity and resolution of the zoom optical lens, in one embodiment of the present invention, the total optical length of the zoom optical system 100 is TTL, the first lens group 1 includes a first lens 11, the first lens 11 is disposed close to the object side, and the aperture of the first lens 11 is øL11, 0.383 < øL11 / TTL < 0.497. This configuration, by reasonably controlling the ratio of the aperture of the first lens 11 to the total optical length, can effectively optimize the amount of light entering the lens, improve the brightness of the image plane 7, and enhance the uniformity of edge image quality while ensuring system compactness.
[0045] Of course, the present invention does not limit the specific value of the aperture of the first lens 11. In actual setting, the specific value of the aperture of the first lens 11 can be selected according to the requirements.
[0046] In a specific embodiment of the present invention, the aperture of the first lens 11 can be set to 26mm, in which case øL11 / TTL=0.433.
[0047] Furthermore, in this invention, it is also necessary to ensure the displacement of the second lens group 2, the third lens group 3, and the fourth lens group 4. The displacement of the second lens group 2, the third lens group 3, and the fourth lens group 4 should be determined based on the total optical length of the zoom optical system 100. For example, in one embodiment of this invention, the total optical length of the zoom optical system 100 is TTL, the displacement of the second lens group 2 is ΔZ1(WT), and 0.281 < ΔZ1(WT) / TTL < 0.365.
[0048] It is understood that the displacement of the second mirror group 2 can be any value within its range. In the embodiments of the present invention, the displacement of the second mirror group 2 can be set to any value within the range. In actual setting, it can be selected according to the requirements.
[0049] In a specific embodiment of the present invention, the displacement of the second mirror group 2 can be set to 19.07 mm, at which time ΔZ1(WT) / TTL=0.317.
[0050] Furthermore, the present invention does not limit the displacement of the third lens group 3. In another embodiment of the present invention, the total optical length of the zoom optical system 100 is TTL, and the displacement of the third lens group 3 is ΔZ2(WT), where 0.07 < ΔZ2(WT) / TTL < 0.091.
[0051] Similarly, the displacement of the third mirror group 3 can be any value within its range. In the embodiments of the present invention, the displacement of the third mirror group 3 can be set to any value within the range. In actual settings, it can be selected according to the requirements.
[0052] In a specific embodiment of the present invention, the displacement of the third mirror group 3 can be set to 4.75 mm, at which time ΔZ2(WT) / TTL=0.079.
[0053] Furthermore, the present invention does not limit the displacement of the fourth lens group 4. In another embodiment of the present invention, the total optical length of the zoom optical system 100 is TTL, and the displacement of the fourth lens group 4 is ΔF(WT), where 0.055 < ΔF(WT) / TTL < 0.072.
[0054] Of course, the displacement of the fourth mirror group 4 can be any value within its range. In actual settings, it can be selected according to the requirements. In a specific embodiment of the present invention, the displacement of the fourth mirror group 4 can be set to 3.76mm, ΔF(WT) / TTL=0.063.
[0055] In addition, in the present invention, the zoom optical system 100 further includes an aperture 5, which is disposed between the second lens group 2 and the third lens group 3. The distance between the aperture 5 and the image plane 7 is L, and the overall optical length of the zoom optical system 100 is TTL, where 0.297 < L / TTL < 0.385. The setting of the aperture 5 can adjust the light flux according to the actual situation and improve the imaging quality.
[0056] Moreover, in the present invention, the specific value of the distance between the aperture 5 and the image plane 7 can also be set to any value within the range, and the present invention does not limit this.
[0057] For example, in an embodiment of the present invention, the distance between the aperture 5 and the image plane 7 can be set to 20.14 mm. At this time, L / TTL = 0.335, which is within the corresponding range.
[0058] In order to further improve the imaging quality, in a further embodiment of the present invention, the zoom optical system 100 further includes a filter 6, which is disposed between the fourth lens group 4 and the image plane 7. The setting of the filter 6 can screen the light entering the image plane 7, filter out the light of a specific wavelength band, so as to reduce the interference of stray light on imaging, and further improve the clarity and color reproduction of the imaging of the zoom optical system 100.
[0059] In addition, in the above embodiment, 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 41, and the eleventh lens 42 can all be set as spherical lenses. With such a setting, using spherical lenses can reduce costs, have a lower assembly sensitivity, and improve the yield rate of finished products while ensuring image quality and reliability.
[0060] Specifically, in a specific embodiment, the surface type, radius of curvature, thickness, refractive index of the material, and Abbe number of the material of the lenses in this embodiment are shown in Table 1 below: Table 1
[0061] It can be understood that in this embodiment, the first lens 11 and the second lens 12 are adhesively connected and disposed, and the seventh lens 31 is set as an aspherical lens. Furthermore, in this embodiment, the aspherical surface shape of the aspherical lens satisfies the following conditions:
[0062] Where c is the curvature corresponding to the radius, y is the radial coordinate (its unit is the same as the lens length unit), k is the conic quadratic coefficient (when the k coefficient is less than -1, the surface curve is a hyperbola; when the k coefficient is equal to -1, it is a parabola; when the k coefficient is between -1 and 0, it is an ellipse; when the k coefficient is equal to 0, it is a circle; and when the k coefficient is greater than 0, it is an oval), A, B, C, D, E, F, G, and H are higher-order aspherical coefficients (please refer to Table 2 below). The shape and size of the aspherical surfaces of the object side and image side of the lens can be set by using the above parameters.
[0063] Table 2 Conic coefficients and aspherical coefficients corresponding to aspherical lenses
[0064] This setup, by rationally allocating the lens power and adjusting the glass shape and material combination, effectively eliminates chromatic aberration and secondary spectrum, allowing spherical aberration, coma, astigmatism, etc. on each lens to compensate and cancel each other out, thereby achieving a clear imaging effect and realizing optimal correction of higher-order aberrations and chromatic aberration.
[0065] It should be further noted that, in this embodiment, the aperture of the zoom optical system 100 is Fno, and 2.61 ≤ Fno ≤ 3.63. Thus, the zoom optical system 100 has a large aperture, enabling it to maintain excellent imaging performance in low-light environments, meeting the imaging requirements of both bright and dark environments, and achieving night vision functionality.
[0066] Please see Figure 4 , Figure 4 The diagram shows the MTF of the zoom optical system 100 provided by the present invention: 125 lp / mm. From left to right, the diagram shows the zoom optical system 100 at the optical power, mid-range, and telephoto ends.
[0067] Please see Figure 5 , Figure 5 This is a schematic diagram of the MTF vs Field of the zoom optical system provided by the present invention. From left to right, the diagram shows the zoom optical system 100 at the optical power, mid-range, and telephoto ends.
[0068] Please see Figure 6 , Figure 6 This is a schematic diagram of the zoom optical system 100 at 125 lp / mm (defocus MTF) provided by the present invention. From left to right, the diagram shows the zoom optical system 100 at the optical power, mid-range, and telephoto ends.
[0069] Please see Figure 7 , Figure 7This is an FCD schematic diagram of the zoom optical system provided by the present invention. From left to right, the diagram shows the zoom optical system 100 at the optical power, mid-range, and telephoto ends.
[0070] Please see Figure 8 , Figure 8 This is a schematic diagram of the zoom optical system provided by the present invention. From left to right, the diagram shows the zoom optical system 100 at the optical power, mid-range, and telephoto ends.
[0071] Please see Figure 9 , Figure 9 This is a schematic diagram of the zoom optical system provided by the present invention. From left to right, the diagram shows the zoom optical system 100 at the optical power, mid-range, and telephoto ends.
[0072] Please see Figure 10 , Figure 10 This is a schematic diagram of the zoom optical system provided by the present invention. From left to right, the diagram shows the zoom optical system 100 at the optical power, mid-range, and telephoto ends.
[0073] Furthermore, the varying intervals between the lens groups of the zoom optical system 100 from the Wide end (wide-angle end) to the Tele end (telephoto end) in this embodiment are shown in Table 3: Table 3
[0074] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within 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 arranged correspondingly along the optical axis. The zoom optical system includes a first lens group, a second lens group, a third lens group, a fourth lens group, and an image plane arranged sequentially from the object side to the image side. The second lens group, the third lens group, and the fourth lens group are all movable along the optical axis. The second lens group and the third lens group are used for zooming, and the fourth lens group is used for focusing. The total optical length of the zoom optical system is controlled within 60.1 mm. Wherein, the focal length of the zoom optical system at the wide-angle end is fw, the focal length at the telephoto end is ft, 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, and the focal length of the fourth lens group is f4. The zoom optical system satisfies the following conditions: fw = 4.85 mm; and ft = 72.04 mm; and 0.131 ≤ fw / f1 ≤ 0.177; and -0.796 ≤ fw / f2 ≤ -0.588; and 0.291 ≤ fw / f3 ≤ 0.394; and 0.240 ≤ fw / f4 ≤ 325.
2. The zoom optical system as described in claim 1, characterized in that, The optical power of the first lens group is positive; The optical power of the second lens group is negative; The optical power of the third lens group is positive; The optical power of the fourth lens group is positive.
3. The zoom optical system as described in claim 1, characterized in that, The first lens group includes a first lens, a second lens, and a third lens arranged sequentially from the object side to the image side. The first lens has a negative optical power, the second lens has a positive optical power, and the third lens has a positive optical power. The first lens and the second lens are cemented 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 -0.699≤f1 / f11≤-0.517; and 0.689≤f1 / f12≤0.932; and 0.723≤f1 / f13≤0.
978.
4. The zoom optical system as described in claim 1, characterized in that, The second lens group includes a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side. The optical power of the fourth lens is negative, the optical power of the fifth lens is negative, and the optical power of the sixth lens is positive. 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 0.778≤f2 / f21≤1.053; and 0.438≤f2 / f22≤0.539; and -0.509≤f2 / f23≤-0.
376.
5. The zoom optical system as described in claim 1, characterized in that, The third lens group includes a seventh lens, an eighth lens, and a ninth lens arranged sequentially from the object side to the image side. The seventh lens has a positive optical power, the eighth lens has a positive optical power, and the ninth lens has a negative optical power. The seventh lens is set as an aspherical lens. The focal length of the seventh lens is f31, the focal length of the eighth lens is f32, and the focal length of the ninth lens is f33, wherein 1.350≤f3 / f31≤1.827; and 0.752≤f3 / f32≤1.017; and -2.754≤f3 / f33≤-2.
036.
6. The zoom optical system as described in claim 1, characterized in that, The fourth lens group includes a tenth lens and an eleventh lens arranged sequentially from the object side to the image side. The optical power of the tenth lens is negative, and the optical power of the eleventh lens is positive. The focal length of the tenth lens is f41, and the focal length of the eleventh lens is f42, wherein -0.624≤f4 / f41≤-0.461; and 1.307≤f4 / f42≤1.
768.
7. The zoom optical system as described in claim 1, characterized in that, The total optical length of the zoom optical system is TTL. The first lens group includes a first lens, which is disposed close to the object side. The aperture of the first lens is øL11, and 0.383 < øL11 / TTL < 0.
497.
8. The zoom optical system as described in claim 1, characterized in that, The total optical length of the zoom optical system is TTL, and the displacement of the second lens group is ΔZ1(WT), where 0.281 < ΔZ1(WT) / TTL < 0.365; and / or, The total optical length of the zoom optical system is TTL, and the displacement of the third lens group is ΔZ2(WT), where 0.07 < ΔZ2(WT) / TTL < 0.091; and / or, The total optical length of the zoom optical system is TTL, and the displacement of the fourth lens group is ΔF(WT), where 0.055 < ΔF(WT) / TTL < 0.
072.
9. The zoom optical system as described in claim 1, characterized in that, The zoom optical system also includes an aperture stop, which is located between the second lens group and the third lens group. The distance between the aperture stop and the image plane is L. The total optical length of the zoom optical system is TTL, 0.
297. <L / TTL<0.385。 10. The zoom optical system as claimed in claim 1, characterized in that, The zoom optical system also includes a filter, which is disposed between the fourth lens group and the image plane.