Ultra-wide-angle prime lens

Abstract

The utility model provides an ultra-wide-angle prime lens, and relates to the technical field of optical lenses. The ultra-wide-angle prime lens comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with positive focal power, a fifth lens with negative focal power, a sixth lens with positive focal power and a seventh lens with positive focal power which are sequentially arranged from the object space to the image space along the optical axis. The lens further comprises a diaphragm which is located between the third lens and the fourth lens. The ultra-wide-angle prime lens provided by the embodiment of the utility model can realize miniaturization under the condition of a large field angle, can be still adaptive to a large-target-surface chip, can be compatible with more chip types, can be confocal day and night, and can meet the use requirements under more conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to an ultra-wide-angle fixed-focus lens. Background Art

[0002] With the development of various intelligent devices, there are more and more scenarios that require a larger viewing angle. Most of the lenses on the market that meet this application scenario have a large aperture of the first lens, resulting in a large volume. However, with the subsequent refined requirements, there is not much space left for lens assembly. The utility model has the advantages of being miniaturized while having a larger target surface, can be applied to more usage scenarios, and has a broad market prospect. Summary of the Utility Model

[0003] An embodiment of the utility model provides an ultra-wide-angle fixed-focus lens, which can achieve miniaturization while still being compatible with a large target surface chip with a large field of view angle, can be compatible with more chip types, and can be confocal day and night, and can meet the usage requirements in more situations.

[0004] An embodiment of the utility model provides an ultra-wide-angle fixed-focus lens, which includes a first lens with negative optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power, and a seventh lens with positive optical power arranged in sequence from the object side to the image side along the optical axis;

[0005] It further includes a diaphragm, and the diaphragm is located between the third lens and the fourth lens.

[0006] Optionally, the refractive index of the third lens is Nd3, and the Abbe number of the third lens is Vd3, satisfying:

[0007] 1.81≤Nd3≤2.02, 17≤Vd3≤19.1.

[0008] Optionally, the object side surface of the first lens bulges towards the object side, and the image side surface of the first lens depresses towards the image side;

[0009] The second lens and the fifth lens are biconcave lenses;

[0010] The fourth lens is a biconvex lens;

[0011] The object side surface of the sixth lens depresses towards the object side, and the image side surface of the sixth lens bulges towards the image side.

[0012] Optionally, the maximum field of view angle of the ultra-wide-angle fixed-focus lens is DFOV, the image height corresponding to the maximum field of view angle of the ultra-wide-angle fixed-focus lens is H, and the total focal length of the ultra-wide-angle fixed-focus lens is f, satisfying:

[0013]

[0014] Optionally, 0.273 ≤ f / H ≤ 0.34.

[0015] Optionally, the optical power of the first lens is the optical power of the second lens is the optical power of the fourth lens is the optical power of the fifth lens is the optical power of the seventh lens is the optical power of the ultra-wide-angle fixed-focus lens is satisfy at least one of the following conditions:

[0016]

[0017] Optionally, the refractive index of the first lens is Nd1, and the Abbe number of the first lens is Vd1, satisfying:

[0018] 1.7 ≤ Nd1 ≤ 1.8, 56.7 ≤ Vd1 ≤ 60.2.

[0019] Optionally, the back focal length of the ultra-wide-angle fixed-focus lens is BFL, and the total lens length of the ultra-wide-angle fixed-focus lens is TTL, satisfying:

[0020] 0.195 ≤ BFL / TTL ≤ 0.224.

[0021] Optionally, the optical effective aperture of the seventh lens is D7, the image height corresponding to the maximum field of view angle of the ultra-wide-angle fixed-focus lens is H, and the total focal length of the ultra-wide-angle fixed-focus lens is f, satisfying:

[0022]

[0023] Optionally, the total lens length of the ultra-wide-angle fixed-focus lens is TTL, and the total focal length of the ultra-wide-angle fixed-focus lens is f, satisfying:

[0024] 0.118 ≤ f / TTL ≤ 0.147.

[0025] An embodiment of the present utility model provides an ultra-wide-angle fixed-focus lens, which includes seven lenses, namely the first lens to the seventh lens. The optical powers of the first lens and the second lens are negative. While introducing a larger field of view range, it makes the refraction of light more gentle, avoiding the introduction of larger aberrations. The third lens with positive optical power converges the passing light to ensure that the light can pass through the aperture of a sufficiently large diaphragm. The fourth lens and the fifth lens are combined with positive and negative optical powers to compensate for aberrations such as chromatic aberration and field curvature generated at the front end, reducing the pressure on the subsequent lenses to correct aberrations. The fifth lens with negative optical power can increase the imaging area of the ultra-wide-angle fixed-focus lens, enabling the final image to reach a larger imaging height. The seventh lens with positive optical power is beneficial for limiting the size of the chief ray angle to meet the requirements of the chip CRA curve. Description of the Drawings

[0026] Figure 1 FIG. 6 is a schematic structural diagram of an ultra-wide-angle fixed-focus lens provided in Embodiment 1 of the present utility model;

[0027] Figure 2 FIG. 10 is a schematic diagram of a light fan diagram of light provided in Embodiment 1 of the present utility model;

[0028] Figure 3 FIG. 14 is a schematic diagram of lateral chromatic aberration provided in Embodiment 1 of the present utility model;

[0029] Figure 4 FIG. 18 is a schematic structural diagram of an ultra-wide-angle fixed-focus lens provided in Embodiment 2 of the present utility model;

[0030] Figure 5 FIG. 22 is a schematic diagram of a light fan diagram of light provided in Embodiment 2 of the present utility model;

[0031] Figure 6 FIG. 26 is a schematic diagram of lateral chromatic aberration provided in Embodiment 2 of the present utility model;

[0032] Figure 7 FIG. 30 is a schematic structural diagram of an ultra-wide-angle fixed-focus lens provided in Embodiment 3 of the present utility model;

[0033] Figure 8 FIG. 34 is a schematic diagram of a light fan diagram of light provided in Embodiment 3 of the present utility model;

[0034] Figure 9 FIG. 38 is a schematic diagram of lateral chromatic aberration provided in Embodiment 3 of the present utility model. Detailed Embodiments

[0035] The present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. Additionally, it should be noted that for the convenience of description, only the parts related to the present utility model rather than all the structures are shown in the drawings.

[0036] Embodiment 1

[0037] Figure 1 The following is a schematic structural diagram of an ultra-wide-angle fixed-focus lens provided by Embodiment 1 of the present utility model. Refer to Figure 1 , the ultra-wide-angle fixed-focus lens includes a first lens L1 with a negative optical power, a second lens L2 with a negative optical power, a third lens L3 with a positive optical power, a fourth lens L4 with a positive optical power, a fifth lens L5 with a negative optical power, a sixth lens L6 with a positive optical power, and a seventh lens L7 with a positive optical power, which are arranged in sequence from the object side to the image side along the optical axis. The ultra-wide-angle fixed-focus lens further includes a stop STO, and the stop STO is located between the third lens L3 and the fourth lens L4.

[0038] Among them, the optical power is equal to the difference between the image-side beam convergence and the object-side beam convergence, and it characterizes the ability of the optical system to deflect light rays. The greater the absolute value of the optical power, the stronger the bending ability of the light rays; the smaller the absolute value of the optical power, the weaker the bending ability of the light rays. When the optical power is positive, the refraction of the light rays is convergent; when the optical power is negative, the refraction of the light rays is divergent.

[0039] The present utility model provides an ultra-wide-angle fixed-focus lens, which includes 7 lenses, namely the first lens L1 to the seventh lens L7. The first lens L1 and the second lens L2 have negative optical powers. While introducing a larger field of view range, the refraction of light rays is made more gentle to avoid introducing larger aberrations. The third lens L3 with a positive optical power converges the passing light rays to ensure that the light rays can pass through the aperture of a sufficiently large stop STO. The fourth lens L4 and the fifth lens L5 are combined with positive and negative optical powers to compensate for aberrations such as chromatic aberration and field curvature generated at the front end, reducing the pressure on the subsequent lenses to correct aberrations. The fifth lens L5 with a negative optical power can increase the imaging area of the ultra-wide-angle fixed-focus lens, so that the final image can reach a larger imaging height. The seventh lens L7 with a positive optical power is beneficial to limiting the size of the chief ray angle to match the requirements of the chip CRA curve.

[0040] Optionally, the first lens L1 and the third lens L3 are glass spherical lenses, and the second lens L2, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are plastic aspherical lenses. The ultra-wide-angle fixed-focus lens provided by the present utility model is a hybrid glass-plastic lens, which uses 2 glass spherical lenses and 5 plastic aspherical lenses.

[0041] Optionally, the object side of the first lens L1 bulges towards the object side, and the image side of the first lens L1 concaves towards the image side. The first lens L1 is a convex-concave lens. The second lens L2 and the fifth lens L5 are biconcave lenses. The fourth lens L4 is a biconvex lens. The object side of the sixth lens L6 concaves towards the object side, and the image side of the sixth lens L6 bulges towards the image side. The sixth lens L6 is a concave-convex lens. The convexity and concavity of the third lens L3 and the seventh lens L7 can be set according to requirements.

[0042] Optionally, the maximum field of view angle of the ultra-wide-angle fixed-focus lens is DFOV, the image height corresponding to the maximum field of view angle of the ultra-wide-angle fixed-focus lens is H, and the total focal length of the ultra-wide-angle fixed-focus lens is f, satisfying: When this relational expression is satisfied, the requirements for large-range detection and high-quality imaging can be balanced, and the requirement for a large target surface can still be met under the condition of an ultra-wide angle, adapting to more chip models on the market.

[0043] Optionally, 0.273 ≤ f / H ≤ 0.34. When the total focal length of the ultra-wide-angle fixed-focus lens and the image height corresponding to the maximum field of view angle of the ultra-wide-angle fixed-focus lens satisfy 0.273 ≤ f / H ≤ 0.34, the condition for the ultra-wide-angle fixed-focus lens to image a large target surface can be achieved.

[0044] Optionally, the optical power of the first lens L1 is The optical power of the second lens L2 is The optical power of the fourth lens L4 is The optical power of the fifth lens L5 is The optical power of the seventh lens L7 is The optical power of the ultra-wide-angle fixed-focus lens is Satisfy at least one of the following conditions:

[0045] Among them, the seventh lens L7 has a positive optical power. When it satisfies the range of , it is beneficial to suppress the angle of the marginal field of view incident on the imaging surface and effectively transmit more light beams to the imaging surface to match the requirements of the chip CRA curve.

[0046] Among them, the first lens L1 and the second lens L2 have negative optical powers. When they satisfy the range of , it is beneficial to converge light rays at a larger angle and meet a larger detection range.

[0047] Among them, the fourth lens L4 and the fifth lens L5 satisfy When within the range, the fourth lens L4 has a positive optical power, and the fifth lens L5 has a negative optical power. The combination of the positive and negative lenses compensates for the chromatic aberration introduced at the front end, providing a basis for day-night co-focus of the ultra-wide-angle fixed-focus lens.

[0048] Optionally, the refractive index of the first lens L1 is Nd1, the Abbe number of the first lens L1 is Vd1, the refractive index of the third lens L3 is Nd3, and the Abbe number of the third lens L3 is Vd3, satisfying: 1.7 ≤ Nd1 ≤ 1.8, 56.7 ≤ Vd1 ≤ 60.2; and / or, 1.81 ≤ Nd3 ≤ 2.02, 17 ≤ Vd3 ≤ 19.1.

[0049] Among them, the first lens L1 is a convex-concave negative lens and is the first lens of the ultra-wide-angle fixed-focus lens. When the first lens L1 satisfies the range of 1.7 ≤ Nd1 ≤ 1.8, it can reduce the light angle, share the aberration pressure of the large field of view, and at the same time effectively compress the lens aperture, realizing the miniaturization of the ultra-wide-angle fixed-focus lens.

[0050] Among them, the third lens L3 has a positive optical power. As the third positive lens L3 satisfies 1.81 ≤ Nd3 ≤ 2.02, 17 ≤ Vd3 ≤ 19.1, it can effectively converge the front-end light, enabling the light to pass smoothly through the aperture STO (i.e., the diaphragm), ensuring that the lens has a large ultra-wide-angle fixed-focus lens with sufficient light input.

[0051] Optionally, the back focal length of the ultra-wide-angle fixed-focus lens is BFL, and the total lens length of the ultra-wide-angle fixed-focus lens is TTL, satisfying: 0.195 ≤ BFL / TTL ≤ 0.224. The reasonable selection of the back focal length and the total lens length of the ultra-wide-angle fixed-focus lens can ensure sufficient installation space for the imaging sensor and the flat filter, and can ensure that the ultra-wide-angle fixed-focus lens will not interfere with the base and the housing during installation, ensuring the simplicity of the assembly process of the ultra-wide-angle fixed-focus lens.

[0052] Optionally, the optical effective aperture of the seventh lens L7 is D7, the image height corresponding to the maximum field of view angle of the ultra-wide-angle fixed-focus lens is H, and the total focal length of the ultra-wide-angle fixed-focus lens is f, satisfying: Through the design of the above parameters of the seventh lens L7, satisfying can make the overall light transition to the image plane relatively smoothly, effectively limit the CRA, and the tolerance and manufacturability of the ultra-wide-angle fixed-focus lens are strong.

[0053] Optionally, the total lens length of the ultra-wide-angle fixed-focus lens is TTL, and the total focal length of the ultra-wide-angle fixed-focus lens is f, satisfying: 0.118 ≤ f / TTL ≤ 0.147. Thus, the volume of the ultra-wide-angle fixed-focus lens can be further effectively compressed, realizing the miniaturization of the ultra-wide-angle fixed-focus lens.

[0054] Exemplarily, the ultra-wide-angle fixed-focus lens further includes a flat glass CG. The flat glass CG is located between the seventh lens L7 and the image plane IMA. The flat glass CG can protect the photosensitive chip in the image sensor, where the imaging chip is used to convert the optical signal collected by the ultra-wide-angle fixed-focus lens into an electrical signal, thereby ensuring the imaging effect of the ultra-wide-angle fixed-focus lens.

[0055] Exemplarily, in Embodiment 1, f / H = 0.317.

[0056] Nd1 = 1.7. Vd1 = 58.1. Nd3 = 1.81. Vd3 = 19.1.

[0057] BFL / TTL = 0.224. f / TTL = 0.147. f = 2.16 mm. The aperture is 2.07. The field of view angle is 180°. TTL = 14.7 mm. Image plane size: φ6.8 mm.

[0058] Table 1 Design values of the ultra-wide-angle fixed-focus lens in Embodiment 1

[0059] Surface number Surface type Radius of curvature Thickness Refractive index Abbe number OBJ Standard surface Infinity Infinity S1 Standard surface 8.025 1.368 1.70 58.1 S2 Standard surface 2.419 2.461 S3 Extended odd aspheric surface -3.572 1.178 1.54 55.7 S4 Extended odd aspheric surface 6.694 0.081 S5 Standard surface 3.119 1.284 1.81 19.1 S6 Standard surface 5.766 0.130 STO Standard surface Infinity 0.034 S7 Extended odd aspheric surface 3.104 1.437 1.54 55.7 S8 Extended odd aspheric surface -2.083 0.036 S9 Extended odd aspheric surface -3.963 0.601 1.64 55.7 S10 Extended odd aspheric surface 4.161 0.194 S11 Extended odd aspheric surface -8.965 1.185 1.54 55.7 S12 Extended odd aspheric surface -2.133 0.048 S13 Extended odd aspheric surface 3.526 1.372 1.54 55.7 S14 Extended odd aspheric surface 6.993 0.300 S15 Standard surface Infinity 0.610 1.52 64.2 S16 Standard surface Infinity 2.390 IMA Standard surface Infinity 0.000

[0060] Table 1 shows a set of design values of the ultra-wide-angle fixed-focus lens in Embodiment 1, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present invention. The ultra-wide-angle fixed-focus lens shown in Table 1 can be Figure 1 as shown in. Generally, a lens includes two surfaces, and each surface is a refracting surface. The surface numbers in Table 1 are numbered according to the surfaces of each lens. Among them, the surface number S1 represents the object side surface of the first lens L1, the surface number S2 represents the image side surface of the first lens L1, and so on, which will not be elaborated here. It should be noted that STO in the surface number column represents the plane where the aperture is located. OBJ in the surface number column represents the object plane. IMA in the surface number column represents the image plane. The radius of curvature represents the degree of curvature of the lens surface. A positive radius of curvature value indicates that the center of curvature is on the side of the surface close to the image side, and a negative radius of curvature value represents that the center of curvature is on the side of the surface far from the image side. "Infinity" in the radius of curvature column represents that the surface is a plane. The unit of the radius of curvature is mm. The value in the thickness column represents the axial distance from the current surface to the next surface. The unit of thickness is mm. The refractive index column represents the refractive index of the medium between the current surface and the next surface. The space in the refractive index column is the refractive index of air, and the refractive index of air is 1. The Abbe number represents the dispersion characteristic of the material between the current surface and the next surface to light, and the space represents that the current position is air.

[0061] Table 2 A design value of the aspheric coefficients of the lenses in the ultra-wide-angle fixed-focus lens in the first embodiment

[0062] Surface number S3 S4 S7 S8 S9 k -1.00265E-02 2.73910E-01 -3.31704E-02 1.77770E-02 -4.80291E-01 <![CDATA[a 4 > 3.11466E-02 2.97606E-02 -2.12305E-02 -3.80028E-01 -5.04303E-01 <![CDATA[a 6 > -6.67527E-03 -1.85237E-02 2.32268E-02 1.04643E+00 1.12333E+00 <![CDATA[a 8 > 1.16257E-03 2.38734E-02 7.91583E-04 -1.45604E+00 -1.82831E+00 <![CDATA[a 10 > -1.02475E-04 -1.90068E-02 -4.45872E-01 5.97096E-01 2.21161E+00 <![CDATA[a 12 > -3.26063E-06 -9.92613E-03 1.71022E+00 1.20807E+00 -2.26892E+00 <![CDATA[a 14 > 1.56325E-06 3.92214E-02 -3.22715E+00 -2.15633E+00 2.06341E+00 <![CDATA[a 16 > -1.07236E-07 -4.46133E-02 3.35765E+00 1.47286E+00 -1.50378E+00 <![CDATA[a 18 > 3.36133E-09 3.09918E-02 -1.84479E+00 -4.11741E-01 7.49552E-01 <![CDATA[a 20 > -3.05344E-10 -1.50318E-02 4.16787E-01 -7.10441E-03 -2.10535E-01 <![CDATA[a 22 > 0.00000E+00 5.20033E-03 0.00000E+00 1.84937E-02 2.06523E-02 <![CDATA[a 24 > 0.00000E+00 -1.23900E-03 0.00000E+00 0.00000E+00 1.69652E-03 <![CDATA[a 26 > 0.00000E+00 1.93332E-04 0.00000E+00 0.00000E+00 0.00000E+00 <![CDATA[a 28 > 0.00000E+00 -1.94523E-05 0.00000E+00 0.00000E+00 0.00000E+00 <![CDATA[a 30 > 0.00000E+00 1.18693E-06 0.00000E+00 0.00000E+00 0.00000E+00 Surface number S10 S11 S12 S13 S14 k 1.72141E-01 1.49725E+00 1.36664E-02 -3.39027E-02 -1.26095E-01 <![CDATA[a 4 > -1.47131E-01 5.10812E-02 1.89079E-02 -1.99850E-02 -2.12659E-02 <![CDATA[a 6 > 1.14785E-01 -9.24778E-02 4.51392E-03 3.27003E-03 3.95055E-03 <![CDATA[a 8 > -7.21841E-02 1.12827E-01 -6.35321E-03 -4.10887E-04 -4.25742E-04 <![CDATA[a 10 > 2.64693E-02 -9.55338E-02 6.26396E-03 2.17960E-04 -5.38098E-05 <![CDATA[a 12 > -1.19013E-03 5.72736E-02 -2.66752E-03 -1.21141E-04 4.12110E-05 <![CDATA[a 14 > -2.93804E-03 -2.21106E-02 7.34009E-04 3.80299E-05 -8.71289E-06 <![CDATA[a 16 > 1.29505E-03 5.11809E-03 -1.28877E-04 -7.31861E-06 9.20360E-07 <![CDATA[a 18 > -2.74730E-04 -6.43390E-04 1.30600E-05 8.90107E-07 -4.94448E-08 <![CDATA[a 20 > 2.60104E-05 3.36768E-05 -1.09356E-06 -6.68488E-08 1.02885E-09 <![CDATA[a 22 > 0.00000E+00 0.00000E+00 1.80979E-07 2.83073E-09 3.51405E-12 <![CDATA[a 24 > 0.00000E+00 0.00000E+00 -1.32373E-08 -5.17363E-11 0.00000E+00

[0063] Table 2 shows a design value of the aspheric coefficients of the lenses in the ultra-wide-angle fixed-focus lens in the first embodiment. The specific numerical values can be adjusted according to product requirements and do not limit the embodiments of the present invention. The ultra-wide-angle fixed-focus lens shown in Table 2 can be Figure 1 as shown in. The meaning of the "surface serial number" column in Table 2 is consistent with that of the "surface serial number" in Table 1. "E" in each embodiment of the present invention represents the exponent with base 10.

[0064] Optionally, the surface of the aspheric lens satisfies the formula:

[0065] where Z is the sag of the aspheric surface, c is the basic curvature at the vertex, k is the conic constant, r is the radial coordinate in the direction perpendicular to the optical axis, a i is the high-order term coefficient, a 2i r 2i is the high-order term of the aspheric surface. i is a positive integer from 2 to 15.

[0066] Figure 2 is a schematic diagram of a ray fan diagram provided by the first embodiment of the present invention. Refer to Figure 2 , in a single subfigure, the abscissa is the normalized beam aperture, and the ordinate is the lateral aberration. Ideally, each curve should completely coincide with the horizontal axis. At this time, all rays in this field of view focus on the same point on the image plane; the ordinate in a single subimage can also be expressed as the maximum dispersion range of the beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also represent the magnitude of the lateral chromatic aberration. As can be seen from Figure 2 , this optical system is well approximated to the horizontal axis at each wavelength in each field of view, indicating that the lateral aberration of each wavelength is well corrected. In addition, the curves of each color do not show obvious dispersion, indicating that this optical system also has good correction for chromatic aberration, ensuring the imaging requirement of clear imaging in the full wavelength band of this optical system.

[0067] Figure 3 is a schematic diagram of the lateral chromatic aberration provided by the first embodiment of the present invention. Refer to Figure 3 , which represents the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the image plane. The horizontal axis represents the lateral chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5 μm, indicating that this optical lens can excellently correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0068] Example 2

[0069] Similarities with Example 1 will not be elaborated here.

[0070] Exemplarily, in Example 2, f / H = 0.34.

[0071] Nd1 = 1.8. Vd1 = 56.7. Nd3 = 2.02. Vd3 = 17.

[0072] BFL / TTL = 0.203. f / TTL = 0.144. f = 2.24 mm. The aperture is 2.05. The field of view angle is 179°. TTL = 15.57 mm. Image plane size: φ6.6 mm.

[0073] Table 3 A set of design values of the ultra-wide-angle fixed-focus lens in Example 2

[0074] Surface number Surface type Radius of curvature Thickness Refractive index Abbe number OBJ Standard surface Infinity Infinity S1 Standard surface 6.214 1.878 1.80 56.7 S2 Standard surface 2.409 2.384 S3 Extended odd aspheric surface -5.523 0.550 1.54 55.7 S4 Extended odd aspheric surface 2.839 0.296 S5 Standard surface 4.976 1.918 2.02 17.0 S6 Standard surface 8.000 0.078 STO Standard surface Infinity 0.020 S7 Extended odd aspheric surface 2.592 1.493 1.54 55.7 S8 Extended odd aspheric surface -2.719 0.068 S9 Extended odd aspheric surface -64.194 0.715 1.64 55.7 S10 Extended odd aspheric surface 3.967 0.100 S11 Extended odd aspheric surface -7.763 1.487 1.54 55.7 S12 Extended odd aspheric surface -2.401 0.020 S13 Extended odd aspheric surface 3.463 1.401 1.54 55.7 S14 Extended odd aspheric surface 6.016 0.159 S15 Standard surface Infinity 0.610 1.52 64.2 S16 Standard surface Infinity 2.390 IMA Standard surface Infinity 0.000

[0075] Table 3 shows a set of design values of the ultra-wide-angle fixed-focus lens in Example 2, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present utility model. The ultra-wide-angle fixed-focus lens shown in Table 3 can be Figure 4 as shown in

[0076] Table 4 A set of design values of the aspherical coefficients of the lenses in the ultra-wide-angle fixed-focus lens in Example 2

[0077] Surface number S3 S4 S7 S8 S9 k 3.99063E-03 -1.68877E-04 1.32234E-04 -2.53303E-04 3.68478E+01 <![CDATA[a 4 > 1.67063E-02 1.39966E-02 -1.70996E-02 -4.52957E-01 -5.58105E-01 <![CDATA[a 6 > -4.60218E-03 -1.77847E-02 2.00370E-02 1.09828E+00 1.13631E+00 <![CDATA[a 8 > 9.84446E-04 2.80581E-02 -3.84384E-03 -1.45437E+00 -1.81796E+00 <![CDATA[a 10 > -1.10779E-04 -2.03894E-02 -4.22322E-01 5.86819E-01 2.22194E+00 <![CDATA[a 12 > -9.74360E-07 -1.07630E-02 1.71384E+00 1.19880E+00 -2.28182E+00 <![CDATA[a 14 > 1.91639E-06 3.95998E-02 -3.25626E+00 -2.14751E+00 2.05094E+00 <![CDATA[a 16 > -1.88126E-07 -4.44979E-02 3.34491E+00 1.47498E+00 -1.49558E+00 <![CDATA[a 18 > 3.01422E-09 3.10088E-02 -1.79865E+00 -4.12697E-01 7.53351E-01 <![CDATA[a 20 > 2.14179E-10 -1.50490E-02 3.97363E-01 -9.99258E-03 -2.10342E-01 <![CDATA[a 22 > 0.00000E+00 5.18441E-03 0.00000E+00 1.98214E-02 1.76511E-02 <![CDATA[a 24 > 0.00000E+00 -1.23869E-03 0.00000E+00 0.00000E+00 2.62811E-03 <![CDATA[a 26 > 0.00000E+00 1.95033E-04 0.00000E+00 0.00000E+00 0.00000E+00 <![CDATA[a 28 > 0.00000E+00 -1.84862E-05 0.00000E+00 0.00000E+00 0.00000E+00 <![CDATA[a 30 > 0.00000E+00 8.36460E-07 0.00000E+00 0.00000E+00 0.00000E+00 Surface number S10 S11 S12 S13 S14 k 9.29517E-05 -8.51530E-05 -2.83817E-07 2.09149E-05 -3.47330E-03 <![CDATA[a 4 > -1.64344E-01 4.57374E-02 1.73122E-02 -1.94486E-02 -2.28658E-02 <![CDATA[a 6 > 1.16745E-01 -8.30719E-02 6.73048E-03 2.80126E-03 4.05921E-03 <![CDATA[a 8 > -7.11557E-02 1.10608E-01 -6.62999E-03 -3.97705E-04 -4.51288E-04 <![CDATA[a 10 > 2.58169E-02 -9.60504E-02 5.99906E-03 2.17438E-04 -6.03171E-05 <![CDATA[a 12 > -1.20708E-03 5.73758E-02 -2.70948E-03 -1.21214E-04 4.13013E-05 <![CDATA[a 14 > -2.88914E-03 -2.20494E-02 7.36328E-04 3.80478E-05 -8.66038E-06 <![CDATA[a 16 > 1.32536E-03 5.11434E-03 -1.26487E-04 -7.31769E-06 9.22703E-07 <![CDATA[a 18 > -2.74701E-04 -6.48391E-04 1.33283E-05 8.89840E-07 -4.94850E-08 <![CDATA[a 20 > 2.26850E-05 3.42478E-05 -1.09429E-06 -6.68389E-08 1.00581E-09 <![CDATA[a 22 > 0.00000E+00 0.00000E+00 1.59087E-07 2.83216E-09 3.58514E-12 <![CDATA[a 24 > 0.00000E+00 0.00000E+00 -1.54746E-08 -5.18721E-11 0.00000E+00

[0078] Table 4 is a set of design values of the aspherical coefficients of the lenses in the ultra-wide-angle fixed-focus lens in Example 2, and the specific numerical values can be adjusted according to product requirements, which is not a limitation to the embodiments of the present utility model. The ultra-wide-angle fixed-focus lens shown in Table 4 can be Figure 4 as shown in

[0079] Figure 6 is a schematic diagram of the lateral chromatic aberration provided in Embodiment 2 of the present utility model. Refer to Figure 6 , the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±4 μm, indicating that this optical lens can excellently correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0080] Example 3

[0081] Similarities with Example 1 and Example 2 will not be elaborated here.

[0082] Exemplarily, in Example 2, f / H = 0.273.

[0083] Nd1 = 1.73. Vd1 = 60.2. Nd3 = 1.96. Vd3 = 18.

[0084] BFL / TTL = 0.195. f / TTL = 0.118. f = 1.83 mm. The aperture is 2.06. The field of view angle is 179°. TTL = 15.5 mm. Image plane size: φ6.7 mm.

[0085] Table 5 A set of design values of the ultra-wide-angle fixed-focus lens in Embodiment III

[0086] Surface number Surface type Radius of curvature Thickness Refractive index Abbe number OBJ Standard surface Infinity Infinity S1 Standard surface 7.819 1.325 1.73 60.2 S2 Standard surface 2.402 2.166 S3 Extended odd aspheric surface -10.246 0.559 1.54 55.7 S4 Extended odd aspheric surface 3.012 0.361 S5 Standard surface 8.233 2.630 1.96 18.0 S6 Standard surface -88.000 0.034 STO Standard surface Infinity 0.095 S7 Extended odd aspheric surface 3.860 1.409 1.54 55.7 S8 Extended odd aspheric surface -2.240 0.068 S9 Extended odd aspheric surface -7.443 0.830 1.64 55.7 S10 Extended odd aspheric surface 3.557 0.164 S11 Extended odd aspheric surface -5.011 1.202 1.54 55.7 S12 Extended odd aspheric surface -2.441 0.029 S13 Extended odd aspheric surface 3.669 1.598 1.54 55.7 S14 Extended odd aspheric surface -50.134 0.029 S15 Standard surface Infinity 0.610 1.52 64.2 S16 Standard surface Infinity 2.390 IMA Standard surface Infinity 0.000

[0087] Table 5 shows a set of design values of the ultra-wide-angle fixed-focus lens in Embodiment III. The specific numerical values can be adjusted according to product requirements and are not a limitation to the embodiments of the present invention. The ultra-wide-angle fixed-focus lens shown in Table 5 can be Figure 7 as shown in

[0088] Table 6 A set of design values of the aspherical coefficients of the lenses in the ultra-wide-angle fixed-focus lens in Embodiment III

[0089] Surface number S3 S4 S7 S8 S9 k 2.24008E+00 -2.68557E-01 -1.52490E-02 -1.51910E-01 -2.70662E+01 <![CDATA[a 4 > 1.39669E-02 1.44778E-02 -1.40932E-02 -4.22428E-01 -5.43050E-01 <![CDATA[a 6 > -5.50694E-03 -2.17757E-02 1.84855E-02 1.07562E+00 1.13327E+00 <![CDATA[a 8 > 1.13185E-03 2.89775E-02 1.41540E-02 -1.45260E+00 -1.81027E+00 <![CDATA[a 10 > -1.05280E-04 -2.08552E-02 -4.66821E-01 5.93334E-01 2.20409E+00 <![CDATA[a 12 > -1.37613E-06 -1.08350E-02 1.73368E+00 1.20718E+00 -2.26507E+00 <![CDATA[a 14 > 1.26797E-06 3.95843E-02 -3.23613E+00 -2.15634E+00 2.05547E+00 <![CDATA[a 16 > -1.54660E-07 -4.43929E-02 3.34712E+00 1.47002E+00 -1.50719E+00 <![CDATA[a 18 > 1.85280E-08 3.09953E-02 -1.83484E+00 -4.12186E-01 7.52754E-01 <![CDATA[a 20 > -1.29956E-09 -1.50602E-02 4.15645E-01 -3.51681E-03 -2.07735E-01 <![CDATA[a 22 > 0.00000E+00 5.18328E-03 0.00000E+00 1.70603E-02 1.96251E-02 <![CDATA[a 24 > 0.00000E+00 -1.23834E-03 0.00000E+00 0.00000E+00 1.35653E-03 <![CDATA[a 26 > 0.00000E+00 1.95297E-04 0.00000E+00 0.00000E+00 0.00000E+00 <![CDATA[a 28 > 0.00000E+00 -1.83220E-05 0.00000E+00 0.00000E+00 0.00000E+00 <![CDATA[a 30 > 0.00000E+00 7.77242E-07 0.00000E+00 0.00000E+00 0.00000E+00 Surface number S10 S11 S12 S13 S14 k 5.02166E-02 -3.12465E-01 7.47176E-03 1.22310E-03 -1.00000E+02 <![CDATA[a 4 > -1.58108E-01 7.08701E-02 2.57623E-02 -1.59079E-02 -1.25465E-02 <![CDATA[a 6 > 1.17096E-01 -9.21246E-02 5.59676E-03 2.21738E-03 3.52283E-03 <![CDATA[a 8 > -7.17258E-02 1.13952E-01 -6.78146E-03 -2.84511E-04 -4.52812E-04 <![CDATA[a 10 > 2.61866E-02 -9.63013E-02 6.31976E-03 2.13573E-04 -4.88982E-05 <![CDATA[a 12 > -1.34239E-03 5.72295E-02 -2.73447E-03 -1.21438E-04 4.09633E-05 <![CDATA[a 14 > -2.93709E-03 -2.20840E-02 7.25006E-04 3.80536E-05 -8.69612E-06 <![CDATA[a 16 > 1.31776E-03 5.12559E-03 -1.27518E-04 -7.31533E-06 9.23514E-07 <![CDATA[a 18 > -2.66353E-04 -6.43074E-04 1.36349E-05 8.89970E-07 -4.93875E-08 <![CDATA[a 20 > 2.24046E-05 3.31405E-05 -9.88456E-07 -6.68560E-08 1.01841E-09 <![CDATA[a 22 > 0.00000E+00 0.00000E+00 1.70578E-07 2.82953E-09 1.67918E-12 <![CDATA[a 24 > 0.00000E+00 0.00000E+00 -2.14455E-08 -5.16210E-11 0.00000E+00

[0090] Table 6 is a set of design values of the aspherical coefficients of the lenses in the ultra-wide-angle fixed-focus lens in Embodiment III. The specific numerical values can be adjusted according to product requirements and are not a limitation to the embodiments of the present invention. The ultra-wide-angle fixed-focus lens shown in Table 6 can be Figure 7 as shown in

[0091] Figure 9 is a schematic diagram of the lateral chromatic aberration provided in Embodiment III of the present invention. Refer to Figure 9 , and the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±6 μm, indicating that the optical lens can excellently correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0092] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An ultra-wide-angle fixed-focus lens, characterized in that: The invention comprises a first lens with negative optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, a sixth lens with positive optical power and a seventh lens with positive optical power, which are arranged in sequence from the object side to the image side along the optical axis; Also included is an aperture stop located between the third lens and the fourth lens.

2. The ultra-wide-angle fixed-focus lens according to claim 1, characterized in that: The refractive index of the third lens is Nd3, and the Abbe number of the third lens is Vd3, which satisfies: 1.81≤Nd3≤2.02,17≤Vd3≤19.

1.

3. The ultra-wide-angle fixed-focus lens according to claim 1, characterized in that: The object side surface of the first lens is convex toward the object side, and the image side surface of the first lens is concave toward the image side; The second lens and the fifth lens are biconcave lenses; The fourth lens is a biconvex lens; The object-side surface of the sixth lens is concave toward the object side, and the image-side surface of the sixth lens is convex toward the image side.

4. The ultra-wide-angle fixed-focus lens according to claim 1, wherein: The maximum field of view of the ultra-wide-angle fixed-focus lens is DFOV, the image height corresponding to the maximum field of view of the ultra-wide-angle fixed-focus lens is H, and the total focal length of the ultra-wide-angle fixed-focus lens is f, which satisfies:

5. The ultra-wide-angle fixed-focus lens according to claim 4, characterized in that: 0.273≤f / H≤0.

34.

6. The ultra-wide-angle fixed-focus lens according to claim 1, wherein: The optical power of the first lens is The optical power of the second lens is The optical power of the fourth lens is The optical power of the fifth lens is The optical power of the seventh lens is The optical power of the ultra-wide-angle fixed-focus lens is At least one of the following conditions is met:

7. The ultra-wide-angle fixed-focus lens according to claim 3, wherein: The refractive index of the first lens is Nd1, and the Abbe number of the first lens is Vd1, which satisfies: 1.7≤Nd1≤1.8,56.7≤Vd1≤60.

2.

8. The ultra-wide-angle fixed-focus lens according to claim 1, wherein: The back focus of the ultra-wide-angle fixed-focus lens is BFL, and the total lens length of the ultra-wide-angle fixed-focus lens is TTL, which satisfies: 0.195≤BFL / TTL≤0.

224.

9. The ultra-wide-angle fixed-focus lens according to claim 1, wherein: The optical effective aperture of the seventh lens is D7, the image height corresponding to the maximum field angle of the ultra-wide-angle fixed-focus lens is H, and the total focal length of the ultra-wide-angle fixed-focus lens is f, which satisfies:

10. The ultra-wide-angle fixed-focus lens according to claim 1, wherein: The total lens length of the ultra-wide-angle fixed-focus lens is TTL, and the total focal length of the ultra-wide-angle fixed-focus lens is f, which satisfies: 0.118≤f / TTL≤0.147.

Images