A wide-angle lens

Abstract

The present invention discloses a wide-angle lens, which includes a first lens to a seventh lens, each of which 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; the first lens has a negative refractive power; the second lens has a positive refractive power; the third lens has a negative refractive power; the fourth lens has a positive refractive power; the fifth lens has a negative refractive power; the sixth lens has a positive refractive power; the seventh lens has a negative refractive power; the optical imaging lens has only the above seven lenses with refractive power; and the lens satisfies: (FOV×f) / h≥70. The present invention uses seven lenses along the direction from the object side to the image side, and arranges and designs the refractive power and surface shape of each lens. When the spatial frequency of the lens reaches 113lp / mm, the MTF value is still greater than 0.4, the transmission function is well controlled, the resolution is high, the lens has a high resolution, and compared with lenses with the same focal length, it has a wider field of view.

Description

Technical Field

[0001] The present invention relates to the technical field of lenses, and in particular to a wide-angle lens. Background Art

[0002] With the continuous progress of science and technology and the continuous development of society, optical imaging lenses have also developed rapidly in recent years. Optical imaging lenses are widely used in various fields such as smart phones, tablet computers, video conferencing, vehicle monitoring, security monitoring, machine vision systems, etc. However, the wide-angle lenses on the market currently have at least the following shortcomings:

[0003] 1. The resolution of general wide-angle lenses is not high, especially in the edge areas, the resolution is even worse.

[0004] 2. Generally, wide-angle lenses have large chromatic aberration, especially in the edge areas, where chromatic aberration is difficult to control and easily causes purple fringing.

[0005] 3. Generally, wide-angle lenses are large in size and long in total length, which is not conducive to the miniaturization of the lens.

[0006] 4. Generally, the CRA of wide-angle lenses is small, which does not match the existing sensors and easily causes color cast. Summary of the invention

[0007] An object of the present invention is to provide a wide-angle lens to solve at least one of the above problems.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A wide-angle lens, comprising a first lens to a seventh lens in order from an object side to an image side along an optical axis, wherein each of the first lens to the seventh lens comprises 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;

[0010] The first lens has a negative refractive power, and the object side surface and the image side surface of the first lens are concave;

[0011] The second lens has positive refractive power, and the object side surface of the second lens is concave, and the image side surface is convex;

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

[0013] The fourth lens has positive refractive power, and the object side surface and image side surface of the fourth lens are convex;

[0014] The fifth lens has a negative refractive power, and the object side surface of the fifth lens is a convex surface, and the image side surface is a concave surface;

[0015] The sixth lens has positive refractive power, and the object side surface and image side surface of the sixth lens are convex;

[0016] The seventh lens has a negative refractive power, and the object side surface of the seventh lens is a convex surface, and the image side surface is a concave surface;

[0017] The optical imaging lens has only the above-mentioned seven lenses with refractive power;

[0018] And the lens satisfies: (FOV×f) / h≥70, where FOV is the field of view of the lens, f is the focal length of the entire lens, and h is the design image height of the lens.

[0019] Preferably, the lens meets the following condition: 0<|f1 / f2|<1, wherein f1 is the focal length value of the first lens, and f2 is the focal length value of the second lens.

[0020] Preferably, both the first lens and the second lens are crescent-shaped aspherical lenses.

[0021] Preferably, the lens meets the following condition: Vd1-Vd2>30, wherein Vd1 is the Abbe coefficient of the first lens, and Vd2 is the Abbe coefficient of the second lens.

[0022] Preferably, the lens meets the following condition: Vd4-Vd5>30, and Vd4>60, wherein Vd4 is the Abbe coefficient of the fourth lens, and Vd5 is the Abbe coefficient of the fifth lens.

[0023] Preferably, the lens further includes an aperture stop, and the aperture stop is arranged between the fourth lens and the fifth lens.

[0024] Preferably, the fourth lens is a glass aspheric lens, and the remaining lenses are plastic aspheric lenses.

[0025] Preferably, the lens meets the following condition: TTL / h≤3, wherein TTL is the distance from the first lens to the imaging plane on the optical axis.

[0026] Preferably, the lens meets the following condition: TTL<13mm.

[0027] After adopting the above technical solution, the present invention has the following advantages compared with the background technology:

[0028] 1. The present invention adopts seven lenses from the object side to the image side, and arranges and designs the refractive index and surface shape of each lens. When the spatial frequency of the lens reaches 113lp / mm, the MTF value is still greater than 0.4, the transfer function is well controlled, the resolution is high, and the lens has high resolution. Compared with lenses with the same focal length, it has a wider field of view.

[0029] 2. The present invention adopts 436nm-656nm visible wide spectrum design, and the later color is controlled within 4um. The color reproduction of the image is good, ensuring that the picture will not have blue-purple edge color difference.

[0030] 3. The TTL of the lens in the present invention is less than 13 mm. Compared with other lenses, the TTL is shorter under the same imaging plane, so that the overall size of the lens is small and the structure is compact, which conforms to the current trend of miniaturization of flat-panel lenses and can be better applied in various application scenarios.

[0031] 4. The CRA of the lens in the present invention is greater than 32°, and the matching degree with the sensor CRA curve is within ±2°, which solves the problem of color cast or low edge illumination of the lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is an optical structure diagram of the present invention;

[0033] Figure 2 This is the MTF curve of the lens in Example 1 under visible light 436nm-656nm;

[0034] Figure 3 Graph showing field curvature and distortion of the lens in Example 1 under visible light of 546 nm;

[0035] Figure 4 is a lateral chromatic aberration curve of the lens in Example 1 under visible light 436nm-656nm;

[0036] Figure 5 This is the MTF curve of the lens in Example 2 under visible light 436nm-656nm;

[0037] Figure 6 The field curvature and distortion diagram of the lens in Example 2 under visible light 546nm;

[0038] Figure 7 This is a lateral chromatic aberration curve of the lens in Example 2 under visible light 436nm-656nm;

[0039] Figure 8 This is the MTF curve of the lens in Example 3 under visible light 436nm-656nm;

[0040] Fig. 9 The field curvature and distortion diagram of the lens in Example 3 under visible light 546nm;

[0041] Fig.10 This is a lateral chromatic aberration curve of the lens in Example 3 under visible light 436nm-656nm;

[0042] Fig.11This is the MTF curve of the lens in Example 4 under visible light 436nm-656nm;

[0043] Fig.12 The field curvature and distortion diagram of the lens in Example 4 under visible light 546nm;

[0044] Fig.13 This is a lateral chromatic aberration curve of the lens in Example 4 under visible light 436nm-656nm.

[0045] Description of reference numerals:

[0046] First lens 1, second lens 2, third lens 3, fourth lens 4, fifth lens 5, sixth lens 6, seventh lens 7, aperture 8, filter 9. DETAILED DESCRIPTION

[0047] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0048] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0049] In this specification, "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 a specific range of the lens surface through which the imaging light passes. The concave and convex shape of the lens can be judged according to the judgment method of ordinary knowledge in this field, that is, the concave and convex shape 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 (lensdatasheet) 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.

[0050] The present invention discloses a wide-angle lens, which includes a first lens to a seventh lens in sequence along an optical axis from the object side to the image side, wherein the first lens to the seventh lens each include 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;

[0051] The first lens has a negative refractive power, and the object side surface and the image side surface of the first lens are concave;

[0052] The second lens has positive refractive power, and the object side surface of the second lens is concave, and the image side surface is convex;

[0053] The third lens has a negative refractive power, and the object side surface of the third lens is a convex surface, and the image side surface is a concave surface;

[0054] The fourth lens has positive refractive power, and the object side surface and image side surface of the fourth lens are convex;

[0055] The fifth lens has a negative refractive power, and the object side surface of the fifth lens is a convex surface, and the image side surface is a concave surface;

[0056] The sixth lens has positive refractive power, and the object side surface and image side surface of the sixth lens are convex;

[0057] The seventh lens has a negative refractive power, and the object side surface of the seventh lens is a convex surface, and the image side surface is a concave surface;

[0058] The optical imaging lens has only the above-mentioned seven lenses with refractive power;

[0059] And the lens satisfies: (FOV×f) / h≥70, where FOV is the field of view of the lens, f is the focal length of the entire lens, and h is the design image height of the lens, which can achieve large angular resolution and a wider field of view in the same focal length range.

[0060] Preferably, the lens meets the following condition: 0<|f1 / f2|<1, wherein f1 is the focal length of the first lens, and f2 is the focal length of the second lens, which can balance the optical power and improve the system performance.

[0061] Preferably, the first lens and the second lens are both crescent-shaped aspherical lenses, which can better correct distortion.

[0062] Preferably, the lens meets the following condition: Vd1-Vd2>30, wherein Vd1 is the Abbe coefficient of the first lens, and Vd2 is the Abbe coefficient of the second lens. By combining two high and low dispersion lenses, off-axis chromatic aberration can be corrected and resolution can be improved.

[0063] Preferably, the lens meets the following condition: Vd4-Vd5>30, and Vd4>60, wherein Vd4 is the Abbe coefficient of the fourth lens, and Vd5 is the Abbe coefficient of the fifth lens. The fourth lens and the fifth lens can help eliminate the influence of chromatic aberration, reduce field curvature, and correct coma. At the same time, the residual part of the chromatic aberration is used to balance the overall chromatic aberration of the optical system, so that the system as a whole is compact and meets the miniaturization requirements.

[0064] Preferably, the lens further includes an aperture stop, and the aperture stop is arranged between the fourth lens and the fifth lens.

[0065] Preferably, the fourth lens is a glass aspheric lens, and the remaining lenses are plastic aspheric lenses. Aspheric lenses have the advantages of improving field curvature and astigmatism, thereby improving the imaging quality of the lens, and can also reduce the overall weight of the system, which is conducive to the miniaturization of the lens. The equations for the object side and image side curves of the aspheric lens are expressed as follows:

[0066]

[0067] in:

[0068] 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);

[0069] c: the vertex curvature of the aspherical surface;

[0070] K: Conic Constant;

[0071] radial distance;

[0072] r n : Normalization radius (NRADIUS);

[0073] u:r / r n ;

[0074] a m : mth order Q con Coefficient (is the m th Q con coefficient);

[0075] Q m con : mth order Q con Polynomial th Q con polynomial).

[0076] Preferably, the lens meets the following condition: TTL / h≤3, wherein TTL is the distance from the first lens to the imaging plane on the optical axis, which can realize the miniaturization of the optical lens. Compared with other lenses, the TTL is shorter under the same imaging plane.

[0077] Preferably, the lens meets the following condition: TTL<13mm.

[0078] The wide-angle lens of the present invention will be described in detail below with reference to specific embodiments.

[0079] Embodiment 1

[0080] refer to Figure 1 As shown, this embodiment discloses a wide-angle lens, which includes a first lens 1 to a seventh lens 7 in sequence from the object side A1 to the image side A2 along an optical axis, wherein the first lens 1 to the seventh lens 7 each include an object-side surface facing the object side A1 and allowing imaging light to pass through, and an image-side surface facing the image side A2 and allowing imaging light to pass through;

[0081] The first lens 1 has a negative refractive power, and the object side surface and the image side surface of the first lens 1 are concave;

[0082] The second lens 2 has positive refractive power, and the object side surface of the second lens 2 is concave, and the image side surface is convex;

[0083] The third lens 3 has a negative refractive power, and the object side surface of the third lens 3 is a convex surface, and the image side surface is a concave surface;

[0084] 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;

[0085] The fifth lens element 5 has a negative refractive power, and the object side surface of the fifth lens element 5 is a convex surface, and the image side surface is a concave surface;

[0086] The sixth lens element 6 has a positive refractive power, and the object side surface and the image side surface of the sixth lens element 6 are convex;

[0087] The seventh lens element 7 has a negative 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;

[0088] The optical imaging lens has only the above seven lenses with refractive power; and the lens satisfies: (FOV×f) / h≥70, wherein FOV is the field of view angle of the lens, f is the focal length of the entire lens, and h is the design image height of the lens.

[0089] The aperture 8 is disposed between the fourth lens 4 and the fifth lens 5 . The fourth lens 4 is a glass aspheric lens, and the remaining lenses are plastic aspheric lenses.

[0090] The detailed optical data of this specific embodiment are shown in Table 1.

[0091] Table 1 Detailed optical data of Example 1

[0092] surface Radius of curvature thickness Material Refractive Index Dispersion coefficient focal length 0 Subject surface Infinity Infinity 1 First lens -10.988 1.207 plastic 1.535037 55.7107 -3.98 2 2.755 2.244 3 Second lens -7.020 2.719 plastic 1.639729 23.5288 5.52 4 -2.726 0.312 5 The third lens 39.536 0.648 plastic 1.661417 20.4122 -13.64 6 7.366 0.086 7 The fourth lens 4.439 1.452 Glass 1.496997 81.6084 3.48 8 -2.533 0.114 9 STO Infinity 0.096 10 Fifth lens 6.972 0.382 plastic 1.661 20.412 -2.95 11 1.504 0.045 12 The sixth lens 2.120 1.286 plastic 1.535037 55.7107 3.02 13 -5.452 0.525 14 Seventh lens 4.231 0.863 plastic 1.535037 55.7107 -15.12 15 2.584 0.299 16 Optical Filters Infinity 0.210 Glass 1.516798 64.1983 Infinity 17 Infinity 0.495 18 Imaging surface Infinity

[0093] Please refer to the following table for detailed parameter data of the aspheric surfaces of the first lens 1 to the seventh lens 7:

[0094] surface K A4 A6 A8 A10 A12 A14 A16 1 3.59E-03 -8.68E-05 1.23E-06 -4.25E-09 1.20E-12 2 -1.51E-02 -1.18E-02 9.51E-04 -3.98E-06 -3.80E-08 3 2.00E-01 -1.86E-02 4.05E-03 -4.66E-04 2.27E-05 4 -1.86E-04 2.72E-02 -4.69E-03 1.19E-03 -1.58E-04 1.11E-05 5 -5.65E+01 7.30E-03 3.87E-03 -3.56E-03 3.13E-03 -1.27E-03 2.83E-04 -2.47E-05 6 -9.93E+01 -1.41E-02 1.26E-02 4.17E-03 -1.36E-02 1.19E-02 -4.59E-03 7.71E-04 7 -1.71E-01 -3.88E-02 4.07E-02 -3.89E-02 1.59E-02 -2.11E-03 8 7.33E-02 9.00E-02 -1.01E-01 7.59E-02 -3.31E-02 6.08E-03 9 10 4.97E+01 -7.42E-02 9.85E-02 -3.36E-01 5.16E-01 -3.19E-01 11 3.19E-02 -2.62E-01 4.84E-01 -9.52E-01 9.58E-01 -3.91E-01 12 1.94E+00 -1.26E-01 4.00E-01 -8.31E-01 7.62E-01 -2.79E-01 13 -4.87E+01 -3.16E-02 7.23E-02 -1.22E-02 -1.01E-03 2.86E-05 14 -2.98E+01 -8.88E-02 2.65E-02 -4.76E-03 5.80E-04 -5.67E-06 15 -1.32E-01 -9.63E-02 2.38E-02 -5.79E-03 8.15E-04 -5.42E-05 -6.01E-08 16 17 18

[0095] In this specific embodiment, the focal length of the lens is f=1.69mm, f1 / f2=-0.72, the light transmission FNO=2.3, the field of view FOV=136°, the target surface size IMH=5.88mm, the total optical length TTL=12.98mm, CRA>32°, and the matching degree with the sensor CRA curve is within ±2°.

[0096] Please refer to the MTF curve of the lens under 436nm-656nm visible light Figure 2 As can be seen from the figure, the lens has good control over the transmission function and high resolution. When the spatial frequency of the lens reaches 113lp / mm, the MTF value is still greater than 0.4, which meets the requirements of picture clarity. For the field curvature and distortion diagram of the lens under 546nm visible light, please refer to Figure 3 As can be seen from the figure, the optical distortion is controlled at about -30%, and the lens imaging image is less deformed. For the vertical axis chromatic aberration diagram of the lens under 436nm-656nm visible light, please refer to Figure 4 As can be seen from the figure, in the visible 436nm-656nm wide spectrum band, the later color is less than 4um, ensuring that there will be no blue-purple fringing color aberration in the picture, and the color reproduction of the image is good.

[0097] Embodiment 2

[0098] Cooperate Figures 5 to 7 As shown, the surface profile and refractive power of each lens in this embodiment and the first embodiment are substantially the same, but the optical parameters such as the curvature radius of each lens surface and lens thickness are different.

[0099] The detailed optical data of this specific embodiment are shown in Table 2.

[0100] Table 2 Detailed optical data of Example 2

[0101] surface Radius of curvature thickness Material Refractive Index Dispersion coefficient focal length 0 Subject surface Infinity Infinity 1 First lens -10.926 1.198 plastic 1.535037 55.7107 -3.96 2 2.742 2.238 3 Second lens -6.976 2.685 plastic 1.639729 23.5288 5.47 4 -2.701 0.310 5 The third lens 40.270 0.649 plastic 1.661417 20.4122 -13.36 6 7.268 0.087 7 The fourth lens 4.379 1.449 Glass 1.496997 81.6084 3.44 8 -2.503 0.112 9 STO Infinity 0.102 10 Fifth lens 7.060 0.386 plastic 1.661 20.412 -2.90 11 1.488 0.043 12 The sixth lens 2.123 1.286 plastic 1.535037 55.7107 3.00 13 -5.298 0.538 14 Seventh lens 4.255 0.854 plastic 1.535037 55.7107 -14.77 15 2.576 0.296 16 Optical Filters Infinity 0.210 Glass 1.516798 64.1983 Infinity 17 Infinity 0.490 18 Imaging surface Infinity

[0102] Please refer to the following table for detailed parameter data of the aspheric surfaces of the first lens 1 to the seventh lens 7:

[0103]

[0104]

[0105] In this specific embodiment, the focal length of the lens is f=1.69mm, f1 / f2=-0.72, the light transmission FNO=2.3, the field of view FOV=136°, the target surface size IMH=5.88mm, the total optical length TTL=12.93mm, CRA>32°, and the matching degree with the sensor CRA curve is within ±2°.

[0106] Please refer to the MTF curve of the lens under 436nm-656nm visible light Figure 5 As can be seen from the figure, the lens has good control over the transmission function and high resolution. When the spatial frequency of the lens reaches 113lp / mm, the MTF value is still greater than 0.4, which meets the requirements of picture clarity. For the field curvature and distortion diagram of the lens under 546nm visible light, please refer to Figure 6 As can be seen from the figure, the optical distortion is controlled at about -30%, and the lens imaging image is less deformed. For the vertical axis chromatic aberration diagram of the lens under 436nm-656nm visible light, please refer to Figure 7 As can be seen from the figure, in the visible 436nm-656nm wide spectrum band, the later color is less than 4um, ensuring that there will be no blue-purple fringing color aberration in the picture, and the color reproduction of the image is good.

[0107] Embodiment 3

[0108] Cooperate Figures 8 to 10 As shown, the surface profile and refractive power of each lens in this embodiment and the first embodiment are substantially the same, but the optical parameters such as the curvature radius of each lens surface and lens thickness are different.

[0109] The detailed optical data of this specific embodiment are shown in Table 3.

[0110] Table 3 Detailed optical data of Example 3

[0111]

[0112]

[0113] Please refer to the following table for detailed parameter data of the aspheric surfaces of the first lens 1 to the seventh lens 7:

[0114] surface K A4 A6 A8 A10 A12 A14 A16 1 3.58E-03 -8.72E-05 1.24E-06 -4.24E-09 -1.66E-12 2 -1.39E-02 -1.16E-02 9.58E-04 -3.20E-06 1.22E-07 2.85E-08 3 1.88E-01 -1.84E-02 4.01E-03 -4.71E-04 2.34E-05 1.90E-09 4 -3.95E-04 2.75E-02 -4.75E-03 1.19E-03 -1.57E-04 1.11E-05 5 -7.05E+01 7.18E-03 3.91E-03 -3.53E-03 3.08E-03 -1.27E-03 2.86E-04 -2.51E-05 6 -9.92E+01 -1.40E-02 1.26E-02 4.16E-03 -1.37E-02 1.20E-02 -4.64E-03 7.80E-04 7 -2.12E-01 -3.87E-02 4.04E-02 -3.87E-02 1.59E-02 -2.12E-03 8 2.21E-02 8.94E-02 -1.01E-01 7.63E-02 -3.36E-02 6.19E-03 9 10 4.90E+01 -7.55E-02 9.86E-02 -3.34E-01 5.17E-01 -3.20E-01 7.91E-03 11 3.64E-02 -2.64E-01 4.80E-01 -9.54E-01 9.62E-01 -3.93E-01 -8.17E-03 12 1.93E+00 -1.24E-01 3.99E-01 -8.31E-01 7.55E-01 -2.77E-01 -5.30E-03 13 -4.88E+01 -3.17E-02 7.29E-02 -1.21E-02 -1.06E-03 -1.16E-05 4.18E-05 14 -2.92E+01 -8.85E-02 2.66E-02 -4.81E-03 5.81E-04 -4.79E-06 -3.34E-07 15 -1.08E-01 -9.83E-02 2.35E-02 -5.76E-03 8.16E-04 -5.43E-05 -3.04E-08 16 17 18

[0115] In this specific embodiment, the focal length of the lens is f=1.69mm, f1 / f2=-0.72, the light transmission FNO=2.3, the field of view FOV=136°, the target surface size IMH=5.88mm, the total optical length TTL=12.93mm, CRA>32°, and the matching degree with the sensor CRA curve is within ±2°.

[0116] Please refer to the MTF curve of the lens under 436nm-656nm visible light Figure 8 As can be seen from the figure, the lens has good control over the transmission function and high resolution. When the spatial frequency of the lens reaches 113lp / mm, the MTF value is still greater than 0.4, which meets the requirements of picture clarity. For the field curvature and distortion diagram of the lens under 546nm visible light, please refer to Fig. 9 As can be seen from the figure, the optical distortion is controlled at about -30%, and the lens imaging image is less deformed. For the vertical axis chromatic aberration diagram of the lens under 436nm-656nm visible light, please refer to Fig.10 As can be seen from the figure, in the visible 436nm-656nm wide spectrum band, the later color is less than 4um, ensuring that there will be no blue-purple fringing color aberration in the picture, and the color reproduction of the image is good.

[0117] Embodiment 4

[0118] Cooperate Figures 11 to 13 As shown, the surface profile and refractive power of each lens in this embodiment and the first embodiment are substantially the same, but the optical parameters such as the curvature radius of each lens surface and lens thickness are different.

[0119] The detailed optical data of this specific embodiment are shown in Table 4.

[0120] Table 4 Detailed optical data of Example 4

[0121] surface Radius of curvature thickness Material Refractive Index Dispersion coefficient focal length 0 Subject surface Infinity Infinity 1 First lens -10.963 1.193 plastic 1.535037 55.7107 -3.96 2 2.738 2.239 3 Second lens -6.976 2.682 plastic 1.639729 23.5288 5.47 4 -2.701 0.309 5 The third lens 40.651 0.648 plastic 1.661417 20.4122 -13.31 6 7.258 0.087 7 The fourth lens 4.381 1.447 Glass 1.496997 81.6084 3.44 8 -2.502 0.112 9 STO Infinity 0.100 10 Fifth lens 7.065 0.386 plastic 1.661 20.412 -2.90 11 1.489 0.041 12 The sixth lens 2.124 1.290 plastic 1.535037 55.7107 3.00 13 -5.292 0.539 14 Seventh lens 4.266 0.857 plastic 1.535037 55.7107 -14.39 15 2.556 0.297 16 Optical Filters Infinity 0.210 Glass 1.516798 64.1983 Infinity 17 Infinity 0.492 18 Imaging surface Infinity

[0122] Please refer to the following table for detailed parameter data of the aspheric surfaces of the first lens 1 to the seventh lens 7:

[0123]

[0124]

[0125] In this specific embodiment, the focal length of the lens is f=1.70mm, f1 / f2=-0.72, the light transmission FNO=2.3, the field of view FOV=136°, the target surface size IMH=5.90mm, the total optical length TTL=12.93mm, CRA>32°, and the matching degree with the sensor CRA curve is within ±2°.

[0126] Please refer to the MTF curve of the lens under 436nm-656nm visible light Fig.11 As can be seen from the figure, the lens has good control over the transmission function and high resolution. When the spatial frequency of the lens reaches 113lp / mm, the MTF value is still greater than 0.4, which meets the requirements of picture clarity. For the field curvature and distortion diagram of the lens under 546nm visible light, please refer to Fig.12As can be seen from the figure, the optical distortion is controlled at about -30%, and the lens imaging image is less deformed. For the vertical axis chromatic aberration diagram of the lens under 436nm-656nm visible light, please refer to Fig.13 As can be seen from the figure, in the visible 436nm-656nm wide spectrum band, the later color is less than 4um, ensuring that there will be no blue-purple fringing color aberration in the picture, and the color reproduction of the image is good.

[0127] 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. A wide-angle lens, characterized in that: The lens system includes a first lens to a seventh lens in sequence from the object side to the image side along an optical axis, wherein each of the first lens to the seventh 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, and the object side surface and the image side surface of the first lens are concave; The second lens has positive refractive power, and the object side surface of the second lens is concave and the image side surface is convex; The third lens has a negative refractive power, and 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 positive refractive power, and the object side surface and image side surface of the fourth lens are convex; The fifth lens has a negative refractive power, and the object side surface of the fifth lens is a convex surface, and the image side surface is a concave surface; The sixth lens has positive refractive power, and the object side surface and image side surface of the sixth lens are convex; The seventh lens has a negative refractive power, and the object side surface of the seventh lens is a convex surface, and the image side surface is a concave surface; The wide-angle lens has only the seven lenses mentioned above that have diopter power; And the lens satisfies: (FOV×f) / h≥70, where FOV is the field of view of the lens, f is the focal length of the lens, and h is the design image height of the lens; The lens meets the following conditions: Vd1-Vd2>30, where Vd1 is the Abbe coefficient of the first lens, and Vd2 is the Abbe coefficient of the second lens; f1 / f2=-0.72, where f1 is the focal length of the first lens and f2 is the focal length of the second lens; The optical system further includes a stop, which is disposed between the fourth lens and the fifth lens.

2. A wide-angle lens as claimed in claim 1, characterized in that: The first lens and the second lens are both crescent-shaped aspherical lenses.

3. A wide-angle lens as claimed in claim 1, characterized in that: The following condition is met: Vd4-Vd5>30, and Vd4>60, wherein Vd4 is the Abbe coefficient of the fourth lens, and Vd5 is the Abbe coefficient of the fifth lens.

4. A wide-angle lens as claimed in claim 1, characterized in that: The fourth lens is a glass aspheric lens, and the remaining lenses are plastic aspheric lenses.

5. A wide-angle lens as claimed in claim 1, characterized in that: The following condition is met: TTL / h≤3, where TTL is the distance from the first lens to the imaging surface on the optical axis.

6. A wide-angle lens as claimed in claim 5, characterized in that: Meet the following conditions: TTL<13mm.

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