An unmanned aerial vehicle imaging lens

Abstract

The present invention discloses an unmanned aerial vehicle imaging lens, which includes a first lens to a ninth lens in sequence along an optical axis from the object side to the image side, wherein the first lens has a negative refractive power, the second lens has a negative refractive power, the third lens has a negative refractive power, the fourth lens has a positive refractive power, the fifth lens has a positive refractive power, the sixth lens has a negative refractive power, the seventh lens has a positive refractive power, the eighth lens has a positive refractive power, and the ninth lens has a negative refractive power. The imaging lens has only the above nine lenses with refractive power. The imaging lens of the present invention has a short total length, light weight, small temperature drift, good color reproduction, effectively eliminates the blue-purple edge phenomenon, and at the same time weakens the energy of ghost images, and has high imaging quality.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to an unmanned aerial vehicle imaging lens. Background Art

[0002] In recent years, the drone industry has developed rapidly. Drones are usually used for aerial photography, reconnaissance, surveillance, communications, anti-submarine, electronic jamming and other occasions. Therefore, drones have become an important tool in civil and military industries.

[0003] Existing drone imaging lenses have the following problems: ghost images generally exist in strong light sources, affecting the imaging effect; blue-purple fringing phenomenon will appear; the structure is long and the mass is large; the lens temperature drift is large, and when the temperature disturbance is too large, it affects the imaging quality.

[0004] In view of this, the inventor of the present application invented a drone imaging lens. Summary of the invention

[0005] The object of the present invention is to provide an unmanned aerial vehicle imaging lens with short overall length, light weight and high imaging quality.

[0006] To achieve the above object, the present invention adopts the following technical solution: an unmanned aerial vehicle imaging lens, comprising a first lens to a ninth lens in sequence along an optical axis from an object side to an image side, wherein the first lens to the ninth lens each comprises an object side surface facing the object side and allowing imaging light to pass through, and an image side surface facing the image side and allowing imaging light to pass through;

[0007] The first lens has a negative refractive power, the object side surface of the first lens is convex, and the image side surface is concave;

[0008] The second lens has a negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface is a concave surface;

[0009] The third lens has a negative refractive power, the object side surface of the third lens is a convex surface, and the image side surface is a concave surface;

[0010] The fourth lens has a positive refractive power, and the object side surface and the image side surface of the fourth lens are convex;

[0011] The fifth lens has a positive refractive power, and the object side surface and the image side surface of the fifth lens are convex;

[0012] The sixth lens has a negative refractive power, the object side surface of the sixth lens is a concave surface, and the image side surface is a convex surface;

[0013] The seventh lens has a positive refractive power, the object side surface of the seventh lens is a convex surface, and the image side surface is a concave surface;

[0014] The eighth lens has a positive refractive power, and the object side surface and the image side surface of the eighth lens are convex;

[0015] The ninth lens has a negative refractive power, the object side surface of the ninth lens is a concave surface, and the image side surface is a convex surface;

[0016] The imaging lens has only the above-mentioned nine lenses having refractive powers.

[0017] Furthermore, the focal lengths of the first to ninth lenses satisfy:

[0018] -20 <f1<-18,-32<f2<-31,-31<f3<-30,8<f4<9,

[0019] 10 <f5<11,-17<f6<-15,39<f7<41,10<f8<11,-8<f9<-7,

[0020] Among them, f1, f2, f3, f4, f5, f6, f7, f8, and f9 are focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens, respectively.

[0021] Furthermore, the absolute value of the ratio of the focal length of the first lens to the ninth lens to the focal length of the lens satisfies:

[0022] 1.9<|(f1 / f)|<2.1, 3.3<|(f2 / f)|<3.4, ​​3.1<|(f3 / f)|<3.3,

[0023] 0.9<|(f4 / f)|<1, 1<|(f5 / f)|<1.1, 1.6<|(f6 / f)|<1.7,

[0024] 4.1<|(f7 / f)|<4.3, 1.1<|(f8 / f)|<1.2, 0.7<|(f9 / f)|<0.8,

[0025] Among them, f is the focal length of the lens, f1, f2, f3, f4, f5, f6, f7, f8, and f9 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens respectively.

[0026] Furthermore, the image side surface of the third lens and the object side surface of the fourth lens are glued to each other, and the difference in the dispersion coefficient between the third lens and the fourth lens is greater than 17.

[0027] Furthermore, the first lens, the third lens, the fourth lens, the sixth lens and the seventh lens are all glass spherical lenses, and the second lens 2, the fifth lens 5, the eighth lens 8 and the ninth lens 9 are all glass aspherical lenses.

[0028] Furthermore, the seventh lens is made of a material with a negative temperature coefficient of refractive index, and the seventh lens is a positive lens.

[0029] Furthermore, the R value of the object side surface of the fifth lens is greater than 24, the R value of the image side surface of the seventh lens is greater than 17, and the absolute value of the R value of the image side surface of the ninth lens is greater than 18.

[0030] Furthermore, the imaging lens satisfies: TTL=31 mm, wherein TTL is the total optical length of the lens.

[0031] Furthermore, it also includes an aperture, which is located between the fourth lens and the fifth lens.

[0032] After adopting the above technical solution, the present invention has the following advantages:

[0033] 1. The imaging lens of the present invention has a short overall length, light weight, compact structure and strong practicality;

[0034] 2. The imaging lens of the present invention adopts an athermal design with small temperature drift, and can maintain the working state in various temperature environments;

[0035] 3. The CRA of the imaging lens of the present invention is 30°, which matches the sensor, has good color reproduction and uniform illumination;

[0036] 4. The imaging lens of the present invention is designed with apochromatic aberration, which optimizes chromatic aberration and eliminates the blue-purple fringing phenomenon;

[0037] 5. The imaging lens of the present invention effectively reduces the energy of ghost images by controlling the R value of the lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a light path diagram of the imaging lens of Example 1 of the present invention;

[0039] Figure 2 is an MTF curve diagram of the imaging lens of Example 1 of the present invention;

[0040] Figure 3 is a defocus curve diagram of the imaging lens of Example 1 of the present invention;

[0041] Figure 4 is a lateral chromatic aberration diagram of the imaging lens of Example 1 of the present invention;

[0042] Figure 5is an aberration characteristic curve diagram of the imaging lens of Example 1 of the present invention;

[0043] Figure 6 : is a field curvature / distortion diagram of the imaging lens of Example 1 of the present invention;

[0044] Figure 7 This is a light path diagram of the imaging lens of Example 2 of the present invention;

[0045] Figure 8 is an MTF curve diagram of the imaging lens of Example 2 of the present invention;

[0046] Fig. 9 is a defocus curve diagram of the imaging lens of Example 2 of the present invention;

[0047] Fig.10 is a lateral chromatic aberration diagram of the imaging lens of Example 2 of the present invention;

[0048] Fig.11 is an aberration characteristic curve diagram of the imaging lens of Example 2 of the present invention;

[0049] Fig.12 is a field curvature / distortion diagram of the imaging lens of Example 2 of the present invention;

[0050] Fig.13 This is a light path diagram of the imaging lens of Example 3 of the present invention;

[0051] Fig.14 is an MTF curve diagram of the imaging lens of Example 3 of the present invention;

[0052] Fig.15 is a defocus curve diagram of the imaging lens of Example 3 of the present invention;

[0053] Fig.16 is a lateral chromatic aberration diagram of the imaging lens of Example 3 of the present invention;

[0054] Fig.17 is an aberration characteristic curve diagram of the imaging lens of Example 3 of the present invention;

[0055] Fig.18 : is a field curvature / distortion diagram of the imaging lens of Example 3 of the present invention;

[0056] Fig.19 This is a light path diagram of the imaging lens of Example 4 of the present invention;

[0057] Fig. 20 is an MTF curve diagram of the imaging lens of Example 4 of the present invention;

[0058] Fig.21 is a defocus curve diagram of the imaging lens of Example 4 of the present invention;

[0059] Fig. 22is a lateral chromatic aberration diagram of the imaging lens of Example 4 of the present invention;

[0060] Fig.23 is an aberration characteristic curve diagram of the imaging lens of Example 4 of the present invention;

[0061] Fig.24 4 is a field curvature / distortion diagram of the imaging lens according to embodiment 4 of the present invention.

[0062] Description of reference numerals:

[0063] 1-first lens, 2-second lens, 3-third lens, 4-fourth lens, 5-fifth lens, 6-sixth lens, 7-seventh lens, 8-eighth lens, 9-ninth lens, 10-aperture, 11-protective glass. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0065] It should be noted that in the present invention, the terms "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element of the present invention must have a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0066] Here, "a lens having a positive refractive power (or a negative refractive power)" means that the paraxial refractive power of the lens calculated by Gaussian optical theory is positive (or negative). The "object side (or image side) of the lens" is defined as the specific range of the lens surface through which the imaging light passes. The concave and convexity of the lens surface can be judged according to the judgment method of ordinary knowledge in this field, that is, the concave and convexity of the lens surface can be judged by the positive and negative signs of the radius of curvature (abbreviated as R value). R value can be commonly used in optical design software, such as Zemax or CodeV. R value is also commonly found in the lens data sheet of optical design software. For the object side, when the R value is positive, the object side is judged to be convex; when the R value is negative, the object side is judged to be concave. Conversely, for the image side, when the R value is positive, the image side is judged to be concave; when the R value is negative, the image side is judged to be convex.

[0067] The present invention discloses an unmanned aerial vehicle imaging lens, which includes a first lens 1 to a ninth lens 9 in sequence along an optical axis from an object side to an image side, wherein each of the first lens 1 to the ninth lens 9 includes an object side surface facing the object side and allowing imaging light to pass through, and an image side surface facing the image side and allowing imaging light to pass through;

[0068] The first lens 1 has a negative refractive power, the object side surface of the first lens 1 is a convex surface, and the image side surface is a concave surface;

[0069] The second lens 2 has a negative refractive power, the object side surface of the second lens 2 is a convex surface, and the image side surface is a concave surface;

[0070] The third lens 3 has a negative refractive power, the object side surface of the third lens 3 is a convex surface, and the image side surface is a concave surface;

[0071] The fourth lens element 4 has a positive refractive power, and the object side surface and the image side surface of the fourth lens element 4 are convex;

[0072] The fifth lens element 5 has a positive refractive power, and the object side surface and the image side surface of the fifth lens element 5 are convex;

[0073] The sixth lens element 6 has a negative refractive power, the object side surface of the sixth lens element 6 is a concave surface, and the image side surface is a convex surface;

[0074] The seventh lens element 7 has a positive refractive power, the object side surface of the seventh lens element 7 is a convex surface, and the image side surface is a concave surface;

[0075] The eighth lens element 8 has a positive refractive power, and the object side surface and the image side surface of the eighth lens element 8 are convex;

[0076] The ninth lens element 9 has a negative refractive power, the object side surface of the ninth lens element 9 is a concave surface, and the image side surface is a convex surface;

[0077] The imaging lens has only the nine lenses with refractive power, and further includes an aperture 10 , which is located between the fourth lens 4 and the fifth lens 5 .

[0078] Preferably, the focal lengths of the first lens 1 to the ninth lens 9 satisfy:

[0079] -20 <f1<-18,-32<f2<-31,-31<f3<-30,8<f4<9,

[0080] 10 <f5<11,-17<f6<-15,39<f7<41,10<f8<11,-8<f9<-7,

[0081] Among them, f1, f2, f3, f4, f5, f6, f7, f8, and f9 are respectively the focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9. Such reasonable allocation of optical focal length is conducive to improving the performance of the imaging lens.

[0082] Preferably, the absolute value of the ratio of the focal length of the first lens 1 to the ninth lens 9 to the focal length of the lens satisfies:

[0083] 1.9<|(f1 / f)|<2.1, 3.3<|(f2 / f)|<3.4, ​​3.1<|(f3 / f)|<3.3,

[0084] 0.9<|(f4 / f)|<1, 1<|(f5 / f)|<1.1, 1.6<|(f6 / f)|<1.7,

[0085] 4.1<|(f7 / f)|<4.3, 1.1<|(f8 / f)|<1.2, 0.7<|(f9 / f)|<0.8,

[0086] Among them, f is the focal length of the lens, and f1, f2, f3, f4, f5, f6, f7, f8, and f9 are respectively the focal lengths of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, and the ninth lens 9. In this way, the optical system of the imaging lens can be balanced, temperature drift can be compensated, and imaging quality can be guaranteed.

[0087] Preferably, the first lens 1, the third lens 3, the fourth lens 4, the sixth lens 6, and the seventh lens 7 are all glass spherical lenses, and the second lens 2, the fifth lens 5, the eighth lens 8, and the ninth lens 9 are all glass aspherical lenses. The image side surface of the third lens 3 and the object side surface of the fourth lens 4 are glued to each other, and the difference in the dispersion coefficient between the third lens 3 and the fourth lens 4 is greater than 17. The apochromatic design makes the chromatic aberration less than 2.5um, which is well corrected, and eliminates the blue-purple edge phenomenon that is easy to appear in lens imaging.

[0088] Preferably, the seventh lens 7 is made of a material with a negative temperature coefficient of refractive index, and the seventh lens 7 is a positive lens. When the external temperature changes, the use of this material can well offset the influence of temperature change on the back focus of the lens, so that the lens can maintain the temperature drift compensation with the Holder, and can ensure that when the lens is used in a temperature range of -20°C to 70°C, the picture is clear and not out of focus, which can meet the requirements of most usage environments.

[0089] Preferably, the R value of the object side of the fifth lens 5 is greater than 24, the R value of the image side of the seventh lens 7 is greater than 17, and the absolute value of the R value of the image side of the ninth lens 9 is greater than 18. In this way, the energy of the ghost image can be well dispersed, so that the lens has a higher imaging quality under strong light.

[0090] The imaging lens has a TTL of 31 mm, where TTL is the total optical length of the lens. The lens weighs less than 24 g, is light, compact, and highly practical.

[0091] The CRA of the imaging lens is 30°, where CRA is the chief ray angle of the lens. It matches the sensor, has good color reproduction and uniform illumination.

[0092] The F / NO. of the imaging lens is 2.35 or 2.43, where F / NO is the aperture value of the lens, which results in large light transmission, uniform illumination at the edge of the image, and high imaging quality.

[0093] The imaging surface size of the imaging lens is 1 / 1″ inch, and the imaging surface is larger than The imaging surface is large and the imaging effect is good.

[0094] The overall F-tan (Theta) distortion of the imaging lens is less than -1.7%, the corresponding deformation of the image and the object is small, and the picture is clear and not deformed.

[0095] The MTF of the imaging lens is 200mm / lp>0.2, and the resolution can reach 20 million pixels, which ensures the imaging quality. At the same time, it greatly improves the overall static resolution and video resolution of the solution, greatly facilitating the development of subsequent image optimization algorithms.

[0096] The mini infrared imaging lens of the present invention will be described in detail below with reference to specific embodiments.

[0097] Example 1

[0098] like Figure 1 As shown, a drone imaging lens includes a first lens 1 to a ninth lens 9 in sequence from the object side to the image side along an optical axis, wherein each of the first lens 1 to the ninth lens 9 includes an object-side surface facing the object side and allowing imaging light to pass through, and an image-side surface facing the image side and allowing imaging light to pass through;

[0099] The first lens 1 has a negative refractive power, the object side surface of the first lens 1 is convex, and the image side surface is concave;

[0100] The second lens 2 has a negative refractive power, the object side surface of the second lens 2 is a convex surface, and the image side surface is a concave surface;

[0101] The third lens 3 has a negative refractive power, the object side surface of the third lens 3 is convex, and the image side surface is concave;

[0102] The fourth lens element 4 has a positive refractive power, and the object side surface and the image side surface of the fourth lens element 4 are convex;

[0103] The fifth lens element 5 has a positive refractive power, and the object side surface and the image side surface of the fifth lens element 5 are convex;

[0104] The sixth lens element 6 has a negative refractive power, and the object side surface of the sixth lens element 6 is a concave surface, and the image side surface is a convex surface;

[0105] The seventh lens element 7 has a positive refractive power, and the object side surface of the seventh lens element 7 is a convex surface, and the image side surface is a concave surface;

[0106] The eighth lens element 8 has a positive refractive power, and the object side surface and the image side surface of the eighth lens element 8 are convex;

[0107] The ninth lens element 9 has a negative refractive power, the object side surface of the ninth lens element 9 is a concave surface, and the image side surface is a convex surface;

[0108] The imaging lens has only the nine lenses with refractive power, and further includes an aperture 10 , which is located between the fourth lens 4 and the fifth lens 5 .

[0109] In this embodiment, the image side surface of the third lens 3 and the object side surface of the fourth lens 4 are glued to each other to form a glued lens.

[0110] The detailed optical data of this example are shown in Table 1.

[0111] Table 1 Detailed optical data of Example 1

[0112] surface type Size (diameter) Radius of curvature thickness Material Refractive Index Dispersion coefficient focal length OBJ Subject surface 0.000 Infinity Infinity 1 First lens 17.601 29.815 0.797 H-K9L 1.51680 64.198 -19.130 2 13.183 7.377 2.616 3 Second lens 13.082 18.404 0.848 D-ZK3 1.58913 61.163 -31.595 4 12.196 9.113 1.375 5 The third lens 12.038 11.720 0.658 H-ZF52 1.84667 23.787 -30.133 6 The fourth lens 11.166 7.848 3.367 TAFD30 1.88300 40.805 8.685 7 10.489 -359.764 4.507 STO 4.739 Infinity 0.900 9 Fifth lens 5.071 24.377 3.097 FCD1 1.49700 81.608 10.269 10 6.618 -6.206 0.071 11 The sixth lens 6.739 -6.628 0.598 H-ZF2 1.67270 32.171 -15.825 12 7.496 -17.984 0.159 13 Seventh lens 8.776 10.610 1.596 FCD515 1.59282 68.624 39.655 14 8.909 18.201 2.221 15 The eighth lens 10.027 10.919 2.838 H-FK61B 1.49700 81.595 10.788 16 10.388 -9.678 1.873 17 The ninth lens 10.414 -3.917 0.696 H-LAK6A 1.69350 53.348 -7.031 18 12.945 -20.979 0.029 19 Protective glass 13.757 Infinity 1.000 H-K9L 1.51680 64.198 20 14.298 Infinity 1.756 IMA Imaging surface 15.844 Infinity

[0113] In this embodiment, the focal length of the molding lens is f=9.61, the aperture value F / NO.=2.35, and the total optical length TTL=31 mm.

[0114] In this embodiment, the second lens 2, the fifth lens 5, the eighth lens 8, and the ninth lens 9 are all glass aspherical lenses. The equation of the surface curve of the aspherical lens is expressed as follows:

[0115]

[0116] in,

[0117] z: Depth of the aspherical surface (the vertical distance between the point on the aspherical surface that is y away from the optical axis and the tangent plane that is tangent to the vertex on the optical axis of the aspherical surface);

[0118] c: the vertex curvature of the aspherical surface;

[0119] K: Conic Constant;

[0120] radial distance;

[0121] r n : Normalization radius (NRADIUS);

[0122] u:r / r n ;

[0123] a m : mth order Q con Coefficient (is the m th Q con coefficient);

[0124] Q m con : mth order Q con Polynomial th Q con polynomial).

[0125] In this embodiment, aspheric surface data of the second lens 2 , the fifth lens 5 , the eighth lens 8 , and the ninth lens 9 are shown in Table 2.

[0126] Table 2 Aspheric surface data of Example 1

[0127] Surface number K A4 A6 A8 A10 A12 A14 3 5.18 9.835E-04 -4.552E-05 1.320E-06 -2.893E-08 3.480E-10 -2.036E-12 4 0.38 1.034E-03 -5.200E-05 1.372E-06 -3.121E-08 3.011E-10 -7.863E-13 9 -1.25 -6.812E-04 -9.112E-07 -2.312E-05 2.917E-06 -1.762E-07 -2.117E-09 10 0.34 -1.035E-03 -1.359E-06 -4.001E-06 -9.495E-08 2.218E-08 -1.761E-09 15 1.52 -1.049E-03 3.315E-05 -2.488E-06 -4.186E-08 3.501E-09 -2.376E-11 16 -0.57 1.274E-03 8.503E-05 -9.861E-06 2.340E-07 -1.278E-09 1.225E-11 17 -1.65 5.759E-03 -4.361E-04 9.476E-06 5.902E-08 -5.064E-09 4.939E-11 18 7.57 4.356E-03 -3.342E-04 1.137E-05 -1.914E-07 1.370E-09 -1.400E-12

[0128] In this embodiment, please refer to the optical path diagram of the imaging lens. Figure 1 Please refer to the MTF curve under 434nm-656nm light Figure 2 From the figure, we can see that when the spatial frequency of the lens reaches 200lp / mm, the full field transfer function image is still greater than 0.2, and the resolution and imaging quality are high. For the defocus curve under 434nm-656nm light, please refer to Figure 3 As can be seen from the figure, the defocus of the imaging lens is small under light. For the lateral chromatic aberration diagram of the imaging lens under visible light, please refer to Figure 4 As can be seen from the figure, the lens has been designed with apochromatic aberration, which improves the color reproduction of the image, has small color aberration, and the blue-purple fringing phenomenon is not obvious. For the aberration characteristic curve under 434nm-656nm light, please refer to Figure 5 As can be seen from the figure, the aberration value of the imaging lens for visible light is controlled within the range of 0.02mm to 0.05mm. For field curvature / distortion, please refer to Figure 6 From the figure, we can see that the optical distortion is controlled within -1.7%, the corresponding deformation of the image and the object is small, the picture is clear and not deformed, the imaging quality is high, and there is no need for post-image algorithm to correct the distortion, which is easy to apply.

[0129] Example 2

[0130] like Figure 7 As shown, the surface profiles and refractive powers of the lenses of this embodiment and embodiment 1 are substantially the same, but the optical parameters such as the curvature radius of the lens surface and the lens thickness are different.

[0131] The detailed optical data of this example are shown in Table 3.

[0132] Table 3 Detailed optical data of Example 2

[0133] surface type Size (diameter) Radius of curvature thickness Material Refractive Index Dispersion coefficient focal length OBJ Subject surface 0.000 Infinity Infinity 1 First lens 17.171 31.120 0.850 H-K9L 1.51680 64.198 -18.929 2 12.931 7.394 2.470 3 Second lens 12.830 18.699 0.761 D-ZK3 1.58913 61.163 -31.597 4 12.000 9.205 1.572 5 The third lens 11.773 11.806 0.643 H-ZF52 1.84667 23.787 -30.445 6 The fourth lens 10.951 7.918 3.215 TAFD30 1.88300 40.805 8.760 7 10.337 -360.015 4.408 STO 4.948 Infinity 0.900 9 Fifth lens 5.229 25.518 3.315 M-FCD1 1.49710 81.560 10.311 10 6.804 -6.159 0.097 11 The sixth lens 6.910 -6.378 0.547 H-ZF2 1.67270 32.171 -15.825 12 7.657 -16.284 0.120 13 Seventh lens 8.937 10.428 1.611 FCD515 1.59282 68.624 39.747 14 9.029 17.580 2.340 15 The eighth lens 10.089 10.820 2.726 M-FCD1 1.49710 81.560 10.903 16 10.380 -10.008 1.875 17 The ninth lens 10.417 -3.927 0.746 M-LAC130 1.69350 53.201 -7.212 18 12.964 -19.379 0.040 19 Protective glass 13.748 Infinity 1.000 H-K9L 1.51680 64.198 20 14.284 Infinity 1.767 IMA Imaging surface 15.844 Infinity

[0134] In this embodiment, the focal length of the molding lens is f=9.61, the aperture value F / NO.=2.43, and the total optical length TTL=31 mm.

[0135] In this embodiment, aspheric surface data of the second lens 2, the fifth lens 5, the eighth lens 8, and the ninth lens 9 are shown in Table 4.

[0136] Table 4 Aspheric surface data of Example 2

[0137] Surface number K A4 A6 A8 A10 A12 A14 3 5.06 9.729E-04 -4.572E-05 1.322E-06 -2.889E-08 3.469E-10 -2.040E-12 4 0.36 1.019E-03 -5.199E-05 1.379E-06 -3.141E-08 3.015E-10 -7.948E-13 9 -2.20 -7.166E-04 2.936E-05 -2.187E-05 2.567E-06 -2.500E-07 9.849E-09 10 0.27 -1.017E-03 -4.481E-06 -2.574E-06 -1.226E-07 1.464E-08 -1.009E-09 15 1.17 -1.065E-03 3.407E-05 -2.569E-06 -3.965E-08 3.815E-09 -3.163E-11 16 -0.36 1.247E-03 8.367E-05 -9.840E-06 2.375E-07 -1.226E-09 1.257E-11 17 -1.61 6.007E-03 -4.385E-04 9.481E-06 5.896E-08 -5.320E-09 5.625E-11 18 6.48 4.530E-03 -3.351E-04 1.133E-05 -1.913E-07 1.384E-09 -1.462E-12

[0138] In this embodiment, please refer to the optical path diagram of the imaging lens. Figure 7 Please refer to the MTF curve under 434nm-656nm light Figure 8 From the figure, we can see that when the spatial frequency of the lens reaches 200lp / mm, the full field transfer function image is still greater than 0.2, and the resolution and imaging quality are high. For the defocus curve under 434nm-656nm light, please refer to Fig. 9 As can be seen from the figure, the defocus of the imaging lens is small under light. For the lateral chromatic aberration diagram of the imaging lens under visible light, please refer to Fig.10 As can be seen from the figure, the lens has been designed with apochromatic aberration, which improves the color reproduction of the image, has small color aberration, and the blue-purple fringing phenomenon is not obvious. For the aberration characteristic curve under 434nm-656nm light, please refer to Fig.11 As can be seen from the figure, the aberration value of the imaging lens for visible light is controlled within the range of -0.03mm to 0.04mm. For field curvature / distortion, please refer to Fig.12 From the figure, we can see that the optical distortion is controlled within -1.7%, the corresponding deformation of the image and the object is small, the picture is clear and not deformed, the imaging quality is high, and there is no need for post-image algorithm to correct the distortion, which is easy to apply.

[0139] Example 3

[0140] like Fig.13 As shown, the surface profiles and refractive powers of the lenses of this embodiment and embodiment 1 are substantially the same, but the optical parameters such as the curvature radius of the lens surface and the lens thickness are different.

[0141] The detailed optical data of this example are shown in Table 5.

[0142] Table 5 Detailed optical data of Example 3

[0143] surface type Size (diameter) Radius of curvature thickness Material Refractive Index Dispersion coefficient focal length OBJ Subject surface 0.000 Infinity Infinity 1 First lens 17.552 30.477 0.796 H-K9L 1.51680 64.198 -19.051 2 13.166 7.396 2.589 3 Second lens 13.069 18.456 0.773 D-ZK3 1.58913 61.163 -31.520 4 12.239 9.130 1.408 5 The third lens 12.079 11.731 0.648 H-ZF52 1.84667 23.787 -30.283 6 The fourth lens 11.216 7.868 3.371 TAFD30 1.88300 40.805 8.707 7 10.555 -360.051 4.514 STO 4.910 Infinity 0.900 9 Fifth lens 5.200 24.070 3.264 FCD1 1.49700 81.608 10.383 10 6.807 -6.295 0.081 11 The sixth lens 6.919 -6.618 0.571 H-ZF2 1.67270 32.171 -16.010 12 7.670 -17.558 0.064 13 Seventh lens 8.892 10.433 1.616 FCD515 1.59282 68.624 39.055 14 8.995 17.842 2.300 15 The eighth lens 10.054 10.736 2.781 H-FK61B 1.49700 81.595 10.895 16 10.413 -10.042 1.870 17 The ninth lens 10.439 -3.911 0.691 H-LAK6A 1.69350 53.348 -7.065 18 12.976 -20.428 0.025 19 Protective glass 13.775 Infinity 1.000 H-K9L 1.51680 64.198 20 14.311 Infinity 1.741 IMA Imaging surface 15.841 Infinity

[0144] In this embodiment, the focal length of the molding lens is f=9.61, the aperture value F / NO.=2.35, and the total optical length TTL=31 mm.

[0145] In this embodiment, aspheric surface data of the second lens 2, the fifth lens 5, the eighth lens 8, and the ninth lens 9 are shown in Table 6.

[0146] Table 6 Aspheric surface data of Example 3

[0147] Surface number K A4 A6 A8 A10 A12 A14 3 5.11 9.873E-04 -4.556E-05 1.321E-06 -2.894E-08 3.477E-10 -2.051E-12 4 0.38 1.037E-03 -5.181E-05 1.372E-06 -3.125E-08 2.996E-10 -8.210E-13 9 -0.27 -6.801E-04 2.109E-05 -2.108E-05 2.512E-06 -2.214E-07 6.954E-09 10 0.31 -1.019E-03 1.208E-06 -3.132E-06 -1.038E-07 1.664E-08 -1.200E-09 15 1.36 -1.075E-03 3.341E-05 -2.510E-06 -4.271E-08 3.532E-09 -2.478E-11 16 -0.44 1.277E-03 8.391E-05 -9.887E-06 2.355E-07 -1.263E-09 1.139E-11 17 -1.65 5.922E-03 -4.385E-04 9.390E-06 5.960E-08 -5.117E-09 5.187E-11 18 7.33 4.402E-03 -3.329E-04 1.132E-05 -1.915E-07 1.378E-09 -1.330E-12

[0148] In this embodiment, please refer to the optical path diagram of the imaging lens. Fig.13 Please refer to the MTF curve under 434nm-656nm light Fig.14 From the figure, we can see that when the spatial frequency of the lens reaches 200lp / mm, the full field transfer function image is still greater than 0.2, and the resolution and imaging quality are high. For the defocus curve under 434nm-656nm light, please refer to Fig.15 As can be seen from the figure, the defocus of the imaging lens is small under light. For the lateral chromatic aberration diagram of the imaging lens under visible light, please refer to Fig.16 As can be seen from the figure, the lens has been designed with apochromatic aberration, which improves the color reproduction of the image, has small color aberration, and the blue-purple fringing phenomenon is not obvious. For the aberration characteristic curve under 434nm-656nm light, please refer to Fig.17 As can be seen from the figure, the aberration value of the imaging lens for visible light is controlled within the range of -0.02mm to 0.05mm. For field curvature / distortion, please refer to Fig.18 From the figure, we can see that the optical distortion is controlled within -1.7%, the corresponding deformation of the image and the object is small, the picture is clear and not deformed, the imaging quality is high, and there is no need for post-image algorithm to correct the distortion, which is easy to apply.

[0149] Example 4

[0150] like Fig.19 As shown, the surface profiles and refractive powers of the lenses of this embodiment and embodiment 1 are substantially the same, but the optical parameters such as the curvature radius of the lens surface and the lens thickness are different.

[0151] The detailed optical data of this example are shown in Table 7.

[0152] Table 7 Detailed optical data of Example 4

[0153] surface type Size (diameter) Radius of curvature thickness Material Refractive Index Dispersion coefficient focal length OBJ Subject surface 0.000 Infinity Infinity 1 First lens 17.066 31.743 0.850 H-K9L 1.51680 64.198 -18.920 2 12.890 7.428 2.433 3 Second lens 12.778 18.607 0.770 D-ZK3 1.58913 61.163 -31.777 4 11.937 9.206 1.597 5 The third lens 11.695 11.829 0.650 H-ZF52 1.84667 23.787 -30.225 6 The fourth lens 10.874 7.909 3.188 TAFD30 1.88300 40.805 8.749 7 10.275 -359.850 4.360 STO 4.950 Infinity 0.900 9 Fifth lens 5.232 25.090 3.390 M-FCD1 1.49710 81.560 10.266 10 6.836 -6.141 0.098 11 The sixth lens 6.934 -6.291 0.560 H-ZF2 1.67270 32.171 -15.663 12 7.697 -15.998 0.089 13 Seventh lens 8.948 10.447 1.610 FCD515 1.59282 68.624 40.185 14 9.036 17.491 2.330 15 The eighth lens 10.083 10.625 2.710 M-FCD1 1.49710 81.560 10.892 16 10.382 -10.165 1.881 17 The ninth lens 10.433 -3.920 0.780 M-LAC130 1.69350 53.201 -7.276 18 13.002 -18.719 0.039 19 Protective glass 13.765 Infinity 1.000 H-K9L 1.51680 64.198 20 14.297 Infinity 1.766 IMA Imaging surface 15.851 Infinity

[0154] In this embodiment, the focal length of the molding lens is f=9.6, the aperture value F / NO.=2.35, and the total optical length TTL=31 mm.

[0155] In this embodiment, aspheric surface data of the second lens 2, the fifth lens 5, the eighth lens 8, and the ninth lens 9 are shown in Table 8.

[0156] Table 8 Aspheric surface data of Example 4

[0157] Surface number K A4 A6 A8 A10 A12 A14 3 5.11 0.000968482 -4.58802E-05 1.31997E-06 -2.88441E-08 3.47171E-10 -2.07379E-12 4 0.36 0.001019223 -5.21364E-05 1.37815E-06 -3.13957E-08 3.02655E-10 -7.92691E-13 9 -1.38 -7.159E-04 3.531E-05 -2.283E-05 2.578E-06 -2.154E-07 6.286E-09 10 0.32 -1.025E-03 -2.646E-06 -2.268E-06 -1.427E-07 1.642E-08 -1.069E-09 15 1.00 -1.110E-03 3.680E-05 -2.633E-06 -4.212E-08 4.097E-09 -3.800E-11 16 -0.31 1.203E-03 8.596E-05 -9.819E-06 2.382E-07 -1.241E-09 1.257E-11 17 -1.56 6.099E-03 -4.354E-04 9.380E-06 6.240E-08 -5.405E-09 5.698E-11 18 6.10 4.609E-03 -3.354E-04 1.130E-05 -1.911E-07 1.394E-09 -1.593E-12

[0158] In this embodiment, please refer to the optical path diagram of the imaging lens. Fig.19 Please refer to the MTF curve under 434nm-656nm light Fig. 20 From the figure, we can see that when the spatial frequency of the lens reaches 200lp / mm, the full field transfer function image is still greater than 0.2, and the resolution and imaging quality are high. For the defocus curve under 434nm-656nm light, please refer to Fig.21 As can be seen from the figure, the defocus of the imaging lens is small under light. For the lateral chromatic aberration diagram of the imaging lens under visible light, please refer to Fig. 22 As can be seen from the figure, the lens has been designed with apochromatic aberration, which improves the color reproduction of the image, has small color aberration, and the blue-purple fringing phenomenon is not obvious. For the aberration characteristic curve under 434nm-656nm light, please refer to Fig.23 As can be seen from the figure, the aberration value of the imaging lens for visible light is controlled within the range of -0.02mm to 0.04mm. For field curvature / distortion, please refer to Fig.24 From the figure, we can see that the optical distortion is controlled within -1.7%, the corresponding deformation of the image and the object is small, the picture is clear and not deformed, the imaging quality is high, and there is no need for post-image algorithm to correct the distortion, which is easy to apply.

[0159] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An unmanned aerial vehicle imaging lens, characterized in that: The lens system includes a first lens to a ninth lens in sequence from the object side to the image side along an optical axis, wherein each of the first lens to the ninth lens includes an object-side surface facing the object side and allowing imaging light to pass therethrough, and an image-side surface facing the image side and allowing imaging light to pass therethrough; The first lens has a negative refractive power, the object side surface of the first lens is convex, and the image side surface is concave; The second lens has a negative refractive power, the object side surface of the second lens is a convex surface, and the image side surface is a concave surface; The third lens has a negative refractive power, the object side surface of the third lens is a convex surface, and the image side surface is a concave surface; The fourth lens has a positive refractive power, and the object side surface and the image side surface of the fourth lens are convex; The fifth lens has a positive refractive power, and the object side surface and the image side surface of the fifth lens are convex; The sixth lens has a negative refractive power, the object side surface of the sixth lens is a concave surface, and the image side surface is a convex surface; The seventh lens has a positive refractive power, the object side surface of the seventh lens is a convex surface, and the image side surface is a concave surface; The eighth lens has a positive refractive power, and the object side surface and the image side surface of the eighth lens are convex; The ninth lens has a negative refractive power, the object side surface of the ninth lens is a concave surface, and the image side surface is a convex surface; The imaging lens has only the above-mentioned nine lenses with refractive power; The focal lengths of the first to ninth lenses satisfy: -20 <f1<-18,-32<f2<-31,-31<f3<-30,8<f4<9, 10 <f5<11,-17<f6<-15,39<f7<41,10<f8<11,-8<f9<-7, Among them, f1, f2, f3, f4, f5, f6, f7, f8, and f9 are focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens, respectively.

2. The drone imaging lens according to claim 1, characterized in that: The absolute value of the ratio of the focal length of the first lens to the ninth lens to the focal length of the lens satisfies: 1.9<|(f1 / f)|<2.1, 3.3<|(f2 / f)|<3.4, ​​3.1<|(f3 / f)|<3.3, 0.9<|(f4 / f)|<1, 1<|(f5 / f)|<1.1, 1.6<|(f6 / f)|<1.7, 4.1<|(f7 / f)|<4.3, 1.1<|(f8 / f)|<1.2, 0.7<|(f9 / f)|<0.8, Among them, f is the focal length of the lens, f1, f2, f3, f4, f5, f6, f7, f8, and f9 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens respectively.

3. The drone imaging lens according to claim 1, characterized in that: The image side surface of the third lens and the object side surface of the fourth lens are glued to each other, and the difference in the dispersion coefficient between the third lens and the fourth lens is greater than 17.

4. The drone imaging lens according to claim 1 or 3, characterized in that: The first lens, the third lens, the fourth lens, the sixth lens and the seventh lens are all glass spherical lenses, and the second lens, the fifth lens, the eighth lens and the ninth lens are all glass aspherical lenses.

5. The drone imaging lens according to claim 1, characterized in that: The seventh lens is made of a material with a negative refractive index temperature coefficient, and the seventh lens is a positive lens.

6. The drone imaging lens according to claim 1, characterized in that: The R value of the object side surface of the fifth lens is greater than 24, the R value of the image side surface of the seventh lens is greater than 17, and the absolute value of the R value of the image side surface of the ninth lens is greater than 18, wherein R is the radius of curvature.

7. The drone imaging lens according to claim 1, characterized in that: The imaging lens satisfies: TTL=31 mm, where TTL is the total optical length of the lens.

8. The drone imaging lens according to claim 1, characterized in that: Also included is an aperture stop, which is located between the fourth lens and the fifth lens.

Images