A wide-angle, low-distortion optical imaging lens

Abstract

The present invention relates to the field of lens technology. The present invention discloses a wide-angle, low-distortion optical imaging lens, comprising nine lenses; the first lens and the second lens are both convex-concave lenses with negative refractive power; the third lens has a negative refractive power, and both the object side and the image side are concave at the near optical axis; the fourth lens and the ninth lens are both convex-convex lenses with positive refractive power; the fifth lens has a positive refractive power, and its object side is convex, and its image side is convex at the near optical axis; the sixth lens has a positive refractive power, and its object side is concave at the near optical axis, and its image side is convex at the near optical axis; the seventh lens has a negative refractive power; the eighth lens has a positive refractive power; the first lens, the fourth lens, and the ninth lens are all made of glass material, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are all plastic aspheric lenses. The present invention has the advantages of wide angle, small size, low cost, large light transmission, small distortion, high resolution, and good imaging quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of lenses, and in particular relates to a wide-angle, low-distortion optical imaging lens for video conferencing. Background Art

[0002] With the continuous advancement of science and technology and the continuous improvement of living standards, optical imaging lenses have also developed rapidly in recent years. Optical imaging lenses are widely used in various fields such as smart phones, tablets, vehicle monitoring, security monitoring, drone aerial photography, machine vision systems, video conferencing, etc. Therefore, the requirements for optical imaging lenses are getting higher and higher.

[0003] However, the optical imaging lenses currently available on the market for video conferencing still have many shortcomings. For example, they often cannot meet the requirements of small size and light weight. In order to correct chromatic aberration, too many lenses are used, making the overall cost of the lens too high; the light transmittance is small, resulting in insufficient brightness and poor imaging effect under relatively dark conditions; the lens distortion is large, making it difficult to correct imaging at edge positions; the imaging range is small and the captured frame is limited; the lens imaging quality is poor and cannot meet the needs of high-definition imaging, etc. Therefore, it is necessary to improve it to meet the increasing demands of consumers. Summary of the Invention

[0004] The object of the present invention is to provide a wide-angle, low-distortion optical imaging lens to solve the above-mentioned technical problems.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a wide-angle, low-distortion optical imaging lens, comprising a first lens to a ninth lens in sequence along an optical axis from the object side to the image side; the first lens to the ninth lens each comprise 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 a convex surface, and the image-side surface of the first lens is a concave surface; 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 of the second lens is a concave surface; the third lens has a negative refractive power, the object-side surface of the third lens is a concave surface at the near optical axis, and the image-side surface of the third lens is a concave surface at the near optical axis; the fourth lens has a positive refractive power, the object-side surface of the fourth lens is a convex surface, The image side surface of the fourth lens is convex; the fifth lens has a positive refractive power, the object side surface of the fifth lens is convex, and the image side surface of the fifth lens is convex at the near optical axis; the sixth lens has a positive refractive power, the object side surface of the sixth lens is concave at the near optical axis, and the image side surface of the sixth lens is convex at the near optical axis; the seventh lens has a negative refractive power; the eighth lens has a positive refractive power; the ninth lens has a positive refractive power, the object side surface of the ninth lens is convex, and the image side surface of the ninth lens is convex; the first, fourth and ninth lenses are all made of glass, and the second, third, fifth, sixth, seventh and eighth lenses are all plastic aspherical lenses; the only lenses with refractive powers in the optical imaging lens are the first to ninth lenses mentioned above.

[0006] Furthermore, the optical imaging lens also satisfies the following requirements: 10.00mm<|f1|<35.00mm, 6.00mm<|f2|<8.00mm, 8.00mm<|f3|<12.00mm, 6.00mm<|f4|<8.00mm, 7.00mm<|f5|<9.00mm, 7.00mm<|f6|<9.00mm, 3.00mm<|f7|<5.00mm, 6.00mm<|f8|<30.00mm, 7.00mm<|f9|<9.00mm, where 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.

[0007] Further, the optical imaging lens further satisfies: 4.00 < |f1 / f| < 12.00, 2.00 < |f2 / f| < 3.00, 2.50 < |f3 / f| < 4.50, 2.00 < |f4 / f| < 3.00, 2.00 < |f5 / f| < 3.00, 2.50 < |f6 / f| < 3.50, 1.50 < |f7 / f| < 3.00, 2.00 < |f8 / f| < 10.00, 2.00 < |f9 / f| < 4.00, where f is the overall focal length of the optical imaging lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens.

[0008] Further, the optical imaging lens further satisfies: 1.60 < nd1 < 1.95, 30.00 < vd1 < 60.00; 1.50 < nd2 < 1.70, 50.00 < vd2 < 60.00; 1.50 < nd3 < 1.70, 50.00 < vd3 < 60.00; 1.70 < nd4, vd4 < 30.00; 1.50 < nd5 < 1.70, 50.00 < vd5 < 60.00; 1.50 < nd6 < 1.70, 50.00 < vd6 < 60.00; 1.50 < nd7 < 1.70, 19.00 < vd7 < 30.00; 1.50 < nd8 < 1.70, 20.00 < vd8 < 30.00; 1.55 < nd9 < 1.07, 55.00 < vd9 < 70.00; where nd1 - nd9 are the refractive indices of the first lens to the ninth lens respectively, and vd1 - vd9 are the dispersion coefficients of the first lens to the ninth lens respectively.

[0009] Further, the optical imaging lens further satisfies: 1.50 ≤ IMH / EFL ≤ 1.75, where IMH is the image - side semi - image height of the optical imaging lens and f is the overall focal length of the optical imaging lens.

[0010] Further, it further includes an aperture, and the aperture is disposed between the fourth lens and the fifth lens.

[0011] Even further, the optical imaging lens further satisfies: 1.50 < |f 前 / f 后 | < 4.00, where f 前 is the combined focal length of the first lens, the second lens, the third lens and the fourth lens, and f 后 [[ID=2O]]is the combined focal length of the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens.

[0012] Further, the optical imaging lens further satisfies: 2.5 mm < f < 2.9 mm, TTL < 29.00 mm, where f is the overall focal length of the optical imaging lens, and TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis.

[0013] Further, the object side surfaces and image side surfaces of the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are all high-order even aspherical surfaces.

[0014] Further, the object side surface of the seventh lens is concave near the optical axis, and the image side surface of the eighth lens is convex near the optical axis.

[0015] Advantageous technical effects of the present invention:

[0016] The present invention adopts a design combining three glass lenses and six plastic aspherical lenses. By correspondingly designing each lens, it has a wide angle, a large shooting range, enabling the image plane to accommodate a larger picture size; the overall volume of the lens is small, the weight is light, and the cost is low; it has a large aperture, high brightness, and can also have good imaging quality in a relatively dark environment; the distortion control is good, the imaging quality is good, reducing the difficulty of post-correction; the lens image quality is good and the clarity is high. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a structural schematic diagram of Embodiment 1 of the present invention;

[0019] Figure 2 It is a MTF graph of Embodiment 1 of the present invention under visible light of 435 - 650 nm;

[0020] Figure 3 It is a defocus curve graph of 60 lp / mm of Embodiment 1 of the present invention under visible light of 435 - 650 nm;

[0021] Figure 4 It is a lateral chromatic aberration curve graph of Embodiment 1 of the present invention under visible light of 435 nm - 650 nm;

[0022] Figure 5 It is a longitudinal chromatic aberration curve graph of Embodiment 1 of the present invention under visible light of 435 nm - 650 nm;

[0023] Figure 6This is a graph showing the field curvature and distortion curves of Example 1 of the present invention under visible light of 435nm-650nm;

[0024] Figure 7 This is a structural diagram of embodiment 2 of the present invention;

[0025] Figure 8 This is the MTF diagram of Example 2 of the present invention under visible light 435-650nm;

[0026] Figure 9 This is a defocus curve diagram of 60lp / mm under visible light 435-650nm of Example 2 of the present invention;

[0027] Figure 10 This is a lateral chromatic aberration curve of Example 2 of the present invention under visible light 435nm-650nm;

[0028] Figure 11 This is a longitudinal chromatic aberration curve diagram of Example 2 of the present invention under visible light 435nm-650nm;

[0029] Figure 12 This is a graph showing the field curvature and distortion curves of Example 2 of the present invention under visible light of 435nm-650nm;

[0030] Figure 13 This is a schematic structural diagram of embodiment 3 of the present invention;

[0031] Figure 14 This is the MTF diagram of Example 3 of the present invention under visible light 435-650nm;

[0032] Figure 15 This is a defocus curve diagram of 60lp / mm under visible light 435-650nm in Example 3 of the present invention;

[0033] Figure 16 This is a lateral chromatic aberration curve of Example 3 of the present invention under visible light 435nm-650nm;

[0034] Figure 17 This is a longitudinal chromatic aberration curve diagram of Example 3 of the present invention under visible light 435nm-650nm;

[0035] Figure 18 Graph showing the field curvature and distortion of the third embodiment of the present invention under visible light ranging from 435 nm to 650 nm. DETAILED DESCRIPTION

[0036] To further illustrate various embodiments, the present invention is provided with accompanying drawings. These drawings form part of the present disclosure and are primarily used to illustrate the embodiments and, in conjunction with the relevant description in the specification, to explain the operating principles of the embodiments. By referring to these drawings, one of ordinary skill in the art will understand other possible embodiments and the advantages of the present invention. The components in the figures are not drawn to scale, and similar reference numerals are generally used to represent similar components.

[0037] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0038] "A lens having a positive (or negative) refractive power" means that the lens's paraxial refractive power, calculated using Gaussian optics theory, is positive (or negative). The "object-side (or image-side) of a lens" is defined as the specific area of ​​the lens surface through which the imaging light passes. The concavity or convexity of a lens's surface can be determined using the same method commonly used by those skilled in the art: the sign of the radius of curvature (abbreviated as R value) determines the concavity or convexity of the lens's surface. R values ​​are commonly used in optical design software such as Zemax or CodeV. R values ​​are also commonly found in lens data sheets within optical design software. For the object-side surface, a positive R value indicates a convex surface; a negative R value indicates a concave surface. Conversely, for the image-side surface, a positive R value indicates a concave surface; a negative R value indicates a convex surface.

[0039] The present invention discloses a wide-angle, low-distortion optical imaging lens, which comprises a first lens to a ninth lens in sequence from the object side to the image side along an optical axis; the first lens to the ninth lens each comprise 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 a convex surface, and the image-side surface of the first lens is a concave surface; 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 of the second lens is a concave surface; the third lens has a negative refractive power, the object-side surface of the third lens is a concave surface near the optical axis, and the image-side surface of the third lens is a concave surface near the optical axis; the fourth lens has a positive refractive power, the object-side surface of the fourth lens is a convex surface, and the image-side surface of the fourth lens is a concave surface The first lens element is a convex surface; the second lens element is a convex surface; the fourth lens element is a convex surface; the fifth lens element has a positive refractive power, the object-side surface of the fifth lens element is convex, and the image-side surface of the fifth lens element is convex at the near optical axis; the sixth lens element has a positive refractive power, the object-side surface of the sixth lens element is concave at the near optical axis, and the image-side surface of the sixth lens element is convex at the near optical axis; the seventh lens element has a negative refractive power; the eighth lens element has a positive refractive power; the ninth lens element has a positive refractive power, the object-side surface of the ninth lens element is convex, and the image-side surface of the ninth lens element is convex; the first lens element, the fourth lens element and the ninth lens element are all made of glass materials, and the second lens element, the third lens element, the fifth lens element, the sixth lens element, the seventh lens element and the eighth lens element are all plastic aspheric lenses; the lenses with refractive powers in this optical imaging lens are only the first to ninth lenses mentioned above.

[0040] The present invention adopts a design combining three glass lenses and six plastic aspheric lenses, which is beneficial to correcting secondary spectra and high-order aberrations. The use of multiple plastic aspheric lenses can better optimize the optical structure, and at the same time is beneficial to the lens structure design and reduces the lens cost. By designing each lens accordingly, it has a wide angle and a large shooting range, so that the image surface can accommodate a larger frame; the overall size of the lens is small, the weight is light, and the cost is low; it has large light transmission and high brightness, and can have good imaging quality even in darker environments; the distortion control is better, the imaging quality is good, and the difficulty of later correction is reduced; the lens has the advantages of good image quality and high clarity.

[0041] Preferably, the optical imaging lens further satisfies the following requirements: 10.00mm<|f1|<35.00mm, 6.00mm<|f2|<8.00mm, 8.00mm<|f3|<12.00mm, 6.00mm<|f4|<8.00mm, 7.00mm<|f5|<9.00mm, 7.00mm<|f6|<9.00mm, 3.00mm<|f7|<5.00mm, 6.00mm<|f8|<30.00mm, and 7.00mm<|f9|<9.00mm, wherein 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, so that the optical power distribution of the lenses is uniform and reasonable, thereby further improving the imaging quality.

[0042] Preferably, the optical imaging lens further satisfies the following requirements: 4.00<|f1 / f|<12.00, 2.00<|f2 / f|<3.00, 2.50<|f3 / f|<4.50, 2.00<|f4 / f|<3.00, 2.00<|f5 / f|<3.00, 2.50<|f6 / f|<3.50, 1.50<|f7 / f|<3.00, 2.00<|f8 / f|<10.00, 2.0 0<|f9 / f|<4.00, where f is the overall focal length of the optical imaging lens, f1 is the focal length of the first lens element, f2 is the focal length of the second lens element, f3 is the focal length of the third lens element, f4 is the focal length of the fourth lens element, f5 is the focal length of the fifth lens element, f6 is the focal length of the sixth lens element, f7 is the focal length of the seventh lens element, f8 is the focal length of the eighth lens element, and f9 is the focal length of the ninth lens element. This ensures that the optical power of the lenses is evenly and reasonably distributed, further improving imaging quality.

[0043] Preferably, the optical imaging lens further satisfies: 1.60 < nd1 < 1.95, 30.00 < vd1 < 60.00; 1.50 < nd2 < 1.70, 50.00 < vd2 < 60.00; 1.50 < nd3 < 1.70, 50.00 < vd3 < 60.00; 1.70 < nd4, vd4 < 30.00; 1.50 < nd5 < 1.70, 50.00 < vd5 < 60.00; 1.50 < nd6 < 1.70, 50.00 < vd6 < 60.00; 1.50 < nd7 < 1.70, 19.00 < vd7 < 30.00; 1.50 < nd8 < 1.70, 20.00 < vd8 < 30.00; 1.55 < nd9 < 1.07, 55.00 < vd9 < 70.00; where nd1 - nd9 are the refractive indices of the first to ninth lenses respectively, and vd1 - vd9 are the dispersion coefficients of the first to ninth lenses respectively, further optimizing chromatic aberration and spherical aberration and improving imaging quality.

[0044] Preferably, the optical imaging lens further satisfies: 1.50 ≤ IMH / EFL ≤ 1.75, where IMH is the image-side semi-image height of the optical imaging lens and f is the overall focal length of the optical imaging lens.

[0045] Preferably, it further includes an aperture, and the aperture is disposed between the fourth lens and the fifth lens, such that the image sides of the first lens and the second lens are curved towards the aperture direction, which is beneficial to achieving low distortion of the lens.

[0046] More preferably, the optical imaging lens further satisfies: 1.50 < |f 前 / f 后 | < 4.00, where f 前 is the combined focal length of the first, second, third, and fourth lenses, and f 后 is the combined focal length of the fifth, sixth, seventh, eighth, and ninth lenses. Controlling the ratio of the front and rear group focal lengths can better distribute the optical power between the front and rear groups, reduce system aberrations, and improve imaging quality.

[0047] Preferably, the optical imaging lens further satisfies: 2.5mm < f < 2.9mm, TTL < 29.00mm, where f is the overall focal length of the optical imaging lens and TTL is the distance from the object side of the first lens to the imaging plane on the optical axis. The overall volume of the lens is small, the installation is simple, and the practicability is strong.

[0048] Preferably, the object sides and image sides of the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens are all high-order even aspheric surfaces, further correcting spherical aberration and chromatic aberration and improving imaging quality.

[0049] Preferably, the object-side surface of the seventh lens is concave at the near optical axis, and the image-side surface of the eighth lens is convex at the near optical axis, so as to further improve the overall performance.

[0050] The wide-angle, low-distortion optical imaging lens of the present invention will be described in detail below with reference to specific embodiments.

[0051] Example 1

[0052] like Figure 1 As shown, a wide-angle, low-distortion optical imaging lens comprises, in order from object side A1 to image side A2 along an optical axis I, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, an aperture 100, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a protective glass 110, and an imaging surface 120. The first lens 1 to the ninth lens 9 each include an object-side surface facing the object side A1 and through which imaging light passes, and an image-side surface facing the image side A2 and through which imaging light passes.

[0053] The first lens element 1 has a negative refractive power. The object-side surface 11 of the first lens element 1 is convex, and the image-side surface 12 of the first lens element 1 is concave.

[0054] The second lens element 2 has a negative refractive power. The object-side surface 21 of the second lens element 2 is a convex surface, and the image-side surface 22 of the second lens element 2 is a concave surface.

[0055] The third lens element 3 has a negative refractive power. The object-side surface 31 of the third lens element 3 is concave near the optical axis. The image-side surface 32 of the third lens element 3 is also concave near the optical axis.

[0056] The fourth lens element 4 has positive refractive power, an object-side surface 41 of the fourth lens element 4 is a convex surface, and an image-side surface 42 of the fourth lens element 4 is a convex surface.

[0057] The fifth lens element 5 has a positive refractive power. The object-side surface 51 of the fifth lens element 5 is a convex surface. The image-side surface 52 of the fifth lens element 5 is a convex surface near the optical axis.

[0058] The sixth lens element 6 has a positive refractive power. The object-side surface 61 of the sixth lens element 6 is concave near the optical axis, and the image-side surface 62 of the sixth lens element 6 is convex near the optical axis.

[0059] The seventh lens element 7 has a negative refractive power. The object-side surface 71 of the seventh lens element 7 is concave near the optical axis. The image-side surface 72 of the seventh lens element 7 is concave near the optical axis.

[0060] The eighth lens element 8 has a positive refractive power. The object-side surface 81 of the eighth lens element 8 is convex near the optical axis, and the image-side surface 82 of the eighth lens element 8 is convex near the optical axis.

[0061] The ninth lens element 9 has a positive refractive power. The object-side surface 91 of the ninth lens element 9 is a convex surface, and the image-side surface 92 of the ninth lens element 9 is a convex surface.

[0062] The first lens 1 , the fourth lens 4 and the ninth lens 9 are all made of glass materials, and the second lens 2 , the third lens 3 , the fifth lens 5 , the sixth lens 6 , the seventh lens 7 and the eighth lens 8 are all plastic aspherical lenses.

[0063] In this specific embodiment, the aperture 100 is disposed between the fourth lens 4 and the fifth lens 5 , but is not limited thereto. In other embodiments, the aperture 100 may also be disposed at other appropriate positions.

[0064] The detailed optical data of this specific embodiment are shown in Table 1-1.

[0065] Table 1-1 Detailed optical data of Example 1

[0066]

[0067]

[0068] In this specific embodiment, the object side surface 21, object side surface 31, object side surface 51, object side surface 61, object side surface 71, object side surface 81, image side surface 22, image side surface 32, image side surface 52, image side surface 62, image side surface 72, and image side surface 82 are defined according to the following aspheric curve formula:

[0069]

[0070] in:

[0071] r is the distance from a point on the optical surface to the optical axis.

[0072] z is the sagittal height of the point along the optical axis.

[0073] c is the curvature of the surface.

[0074] K is the quadratic constant of the surface.

[0075] A4、A6、A8、A 10 、A 12 、A 14 、A 16 They are: fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order aspheric coefficients.

[0076] Please refer to the table below for detailed parameter data of each aspheric surface:

[0077] Surface number K <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> <![CDATA[A 16 ]]> 21 -9.15 3.656E-04 1.284E-05 3.148E-07 -5.261E-08 2.091E-09 -3.636E-11 2.502E-13 22 -0.74 -9.764E-03 1.127E-03 -2.082E-04 2.963E-05 -2.861E-06 1.529E-07 -3.574E-09 31 1.37 -4.239E-03 1.210E-03 -1.732E-04 1.707E-05 -1.102E-06 4.094E-08 -6.563E-10 32 0.20 -1.049E-03 1.063E-03 -8.795E-05 -8.985E-06 4.188E-06 -5.021E-07 2.307E-08 51 10.29 -4.808E-03 -9.554E-04 -1.325E-04 4.191E-04 -2.785E-04 7.963E-05 -9.094E-06 52 -99.30 -2.048E-03 -4.657E-03 3.227E-04 1.191E-03 -6.222E-04 1.382E-04 -1.008E-05 61 -99.30 6.692E-03 -7.336E-03 -1.357E-03 2.521E-03 -1.116E-03 2.269E-04 -1.676E-05 62 -15.44 -1.371E-02 9.621E-03 -1.437E-02 6.375E-03 -1.384E-03 1.523E-04 -6.722E-06 71 1.49 3.766E-04 9.609E-03 -1.176E-02 5.315E-03 -1.187E-03 1.338E-04 -5.846E-06 72 -44.29 -1.737E-02 3.678E-03 -2.516E-03 7.959E-04 -1.212E-04 9.358E-06 -2.968E-07 81 -99.23 -1.326E-02 5.037E-03 -2.944E-03 8.205E-04 -1.073E-04 6.833E-06 -1.747E-07 82 -10.41 3.240E-03 1.535E-03 -1.028E-04 -2.312E-05 5.498E-06 -3.991E-07 8.323E-09

[0078] Please refer to Table 4 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0079] The MTF curve of this specific embodiment is shown in Figure 2 It can be seen that under the condition of 250lp / mm, the 0.8 field of view is greater than 0.2, achieving 4K imaging clarity. For the defocus curve, please refer to Figure 3 , see the lateral chromatic aberration diagram for details. Figure 4 , longitudinal chromatic aberration diagram is shown in Figure 5 , it can be seen that chromatic aberration and aberration are well corrected, and the imaging quality is good; for details of field curvature and distortion, see Figure 6 From (A) and (B), we can see that both field curvature and distortion are well corrected, with optical distortion ≤9%.

[0080] In this specific embodiment, the optical imaging lens has a focal length f=2.766 mm; an aperture value FNO=2.0; a field of view FOV=120.0°; an image half-height IMH=4.408 mm; and a distance TTL from the object-side surface 11 of the first lens element 1 to the imaging surface 120 on the optical axis I=28.51 mm.

[0081] Example 2

[0082] like Figure 7 As shown, the surface profiles and refractive powers of the lenses of this embodiment and the first embodiment are substantially the same, except that the image-side surface 72 of the seventh lens element 7 is convex near the optical axis, and the object-side surface 81 of the eighth lens element 8 is concave near the optical axis. Furthermore, optical parameters such as the curvature radius and lens thickness of the lens surfaces differ.

[0083] The detailed optical data of this specific embodiment are shown in Table 2-1.

[0084] Table 2-1 Detailed optical data of Example 2

[0085]

[0086]

[0087] Please refer to the following table for detailed parameter data of each aspheric surface in this specific embodiment:

[0088] Surface number K <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> <![CDATA[A 16 ]]> 21 -11.70 2.525E-03 -2.600E-05 -3.635E-06 1.314E-07 1.459E-08 -9.838E-10 1.673E-11 22 -0.63 -3.240E-03 3.304E-04 -4.104E-05 -2.726E-06 1.102E-07 8.529E-08 -7.128E-09 31 8.23 -1.448E-03 2.413E-04 -8.444E-06 1.658E-07 -3.296E-08 -9.391E-09 6.281E-10 32 4.07 8.734E-04 1.614E-04 -1.452E-05 2.432E-06 2.623E-07 -1.478E-07 1.154E-08 51 9.95 1.810E-03 6.552E-04 -1.630E-04 1.407E-05 -2.908E-05 1.692E-05 -2.654E-06 52 -84.94 1.232E-02 1.448E-03 -7.740E-04 4.613E-05 3.878E-06 1.844E-05 -2.760E-06 61 58.10 1.754E-02 -2.974E-03 -4.183E-04 1.014E-04 2.410E-05 -9.518E-06 1.639E-06 62 -1.06 -1.391E-03 -2.320E-03 2.769E-05 1.479E-05 4.154E-06 -7.091E-07 -3.161E-09 71 0.65 1.199E-02 -1.414E-03 -7.116E-05 4.858E-05 2.251E-06 -1.848E-06 3.138E-07 72 68.31 3.078E-03 -2.218E-04 -2.728E-05 1.347E-06 5.746E-07 -1.675E-08 8.737E-10 81 7.13 3.612E-03 7.470E-04 -1.620E-06 -3.568E-06 -1.411E-07 2.563E-08 -1.133E-09 82 -9.56 5.395E-03 7.811E-04 -6.412E-06 -3.019E-06 -1.667E-07 -2.541E-09 1.094E-09

[0089] Please refer to Table 4 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0090] The MTF curve of this specific embodiment is shown in Figure 8 It can be seen that under the condition of 250lp / mm, the 0.8 field of view is greater than 0.2, achieving 4K imaging clarity. For the defocus curve, please refer to Figure 9 , see the lateral chromatic aberration diagram for details. Figure 10 , longitudinal chromatic aberration diagram is shown in Figure 11 , it can be seen that chromatic aberration and aberration are well corrected, and the imaging quality is good; for details of field curvature and distortion, see Figure 12From (A) and (B), we can see that both field curvature and distortion are well corrected, with optical distortion ≤9%.

[0091] In this specific embodiment, the optical imaging lens has a focal length f=2.765 mm; an aperture value FNO=2.0; a field of view FOV=120.0°; an image half-height IMH=4.406 mm; and a distance TTL from the object-side surface 11 of the first lens element 1 to the imaging surface 120 on the optical axis I=27.02 mm.

[0092] Example 3

[0093] like Figure 13 As shown, the surface profiles and refractive powers of the lenses of this embodiment and the first embodiment are substantially the same, except that the object-side surface 81 of the eighth lens 8 is concave near the optical axis. Furthermore, optical parameters such as the curvature radius and lens thickness of the lens surfaces are also different.

[0094] The detailed optical data of this specific embodiment are shown in Table 3-1.

[0095] Table 3-1 Detailed optical data of Example 3

[0096]

[0097] Please refer to the following table for detailed parameter data of each aspheric surface in this specific embodiment:

[0098]

[0099]

[0100] Please refer to Table 4 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0101] The MTF curve of this specific embodiment is shown in Figure 14 It can be seen that under the condition of 250lp / mm, the 0.8 field of view is greater than 0.2, achieving 4K imaging clarity. For the defocus curve, please refer to Figure 15 , see the lateral chromatic aberration diagram for details. Figure 16 , longitudinal chromatic aberration diagram is shown in Figure 17 , it can be seen that chromatic aberration and aberration are well corrected, and the imaging quality is good; for details of field curvature and distortion, see Figure 18 From (A) and (B), we can see that both field curvature and distortion are well corrected, with optical distortion ≤9%.

[0102] In this specific embodiment, the optical imaging lens has a focal length f=2.761 mm; an aperture value FNO=2.0; a field of view FOV=120.0°; an image half-height IMH=4.404 mm; and a distance TTL from the object-side surface 11 of the first lens element 1 to the imaging surface 120 on the optical axis I=28.00 mm.

[0103] Table 4 Values ​​of important parameters of three embodiments of the present invention

[0104]

[0105]

[0106] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A wide-angle, low-distortion optical imaging lens comprising, in order from the object side to the image side along an optical axis, first through ninth lenses; each of the first through ninth lenses having an object-side surface facing the object side and through which imaging light passes, and an image-side surface facing the image side and through which imaging light passes; characterized in that: The first lens has a negative refractive power, the object side surface of the first lens is convex, and the image side surface of the first lens is concave; The second lens element has a negative refractive power, the object-side surface of the second lens element is convex, and the image-side surface of the second lens element is concave; The third lens element has a negative refractive power, and the object-side surface of the third lens element is concave near the optical axis, and the image-side surface of the third lens element is concave near the optical axis; The fourth lens element has a positive refractive power, the object-side surface of the fourth lens element is convex, and the image-side surface of the fourth lens element is convex; The fifth lens element has a positive refractive power, the object-side surface of the fifth lens element is convex, and the image-side surface of the fifth lens element is convex near the optical axis. The sixth lens element has a positive refractive power, the object-side surface of the sixth lens element is concave near the optical axis, and the image-side surface of the sixth lens element is convex near the optical axis; The seventh lens element has a negative refractive power; the eighth lens element has a positive refractive power; The ninth lens element has a positive refractive power, the object-side surface of the ninth lens element is convex, and the image-side surface of the ninth lens element is convex; The first lens, the fourth lens and the ninth lens are all made of glass materials, and the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all plastic aspherical lenses; The optical imaging lens has only the first to ninth lenses having refractive powers; The optical imaging lens further satisfies the following requirements: 10.00mm<|f1|<35.00mm, 6.00mm<|f2|<8.00mm, 8.00mm<|f3|<12.00mm, 6.00mm<|f4|<8.00mm, 7.00mm<|f5|<9.00mm, 7.00mm<|f6|<9.00mm, 3.00mm<|f7|<5.00mm, 6.00mm<|f8|<30.00mm, 7.00mm<|f9|<9.00mm, where 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.

2. The wide-angle, low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens further satisfies the following requirements: 4.00<|f1 / f|<12.00, 2.00<|f2 / f|<3.00, 2.50<|f3 / f|<4.50, 2.00<|f4 / f|<3.00, 2.00<|f5 / f|<3.00, 2.50<|f6 / f|<3.50, 1.00<|f7 / f|<2.00, 2.00<|f8 / f|<10.00, and 2.00<|f9 / f|<4.00, where f is the overall focal length of the optical imaging lens.

3. The wide-angle, low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens further satisfies: 1.60 < nd1 < 1.95, 30.00 < vd1 < 60.00; 1.50 < nd2 < 1.70, 50.00 < vd2 < 60.00; 1.50 < nd3 < 1.70, 50.00 < vd3 < 60.00; 1.70 < nd4, vd4 < 30.00; 1.50 < nd5 < 1.70, 50.00 < vd5 < 60.00; 1.50 < nd6 < 1.70, 50.00 < vd6 < 60.00; 1.50 < nd7 < 1.70, 19.00 < vd7 < 30.00; 1.50 < nd8 < 1.70, 20.00 < vd8 < 30.00; 1.55 < nd9 < 1.70, 55.00 < vd9 < 70.00; where, nd1 - nd9 are the refractive indices of the first lens to the ninth lens respectively, and vd1 - vd9 are the dispersion coefficients of the first lens to the ninth lens respectively.

4. The wide-angle, low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens further satisfies: 1.50 ≤ IMH / EFL ≤ 1.75, where, IMH is the image-side semi-image height of the optical imaging lens, and f is the overall focal length of the optical imaging lens.

5. The wide-angle, low-distortion optical imaging lens according to claim 1, wherein: It further includes an aperture, and the aperture is disposed between the fourth lens and the fifth lens.

6. The wide-angle, low-distortion optical imaging lens according to claim 5, wherein: The optical imaging lens also meets the following requirements: 1.50<|f 前 / f 后 |<4.00, where f 前 is the combined focal length of the first, second, third and fourth lenses, f 后 is the combined focal length of the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens.

7. The wide-angle, low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens further satisfies: 2.5mm < f < 2.9mm, TTL < 29.00mm, where, f is the overall focal length of the optical imaging lens, and TTL is the distance from the object side surface of the first lens to the imaging surface on the optical axis.

8. The wide-angle, low-distortion optical imaging lens according to claim 1, wherein: The object side surface and the image side surface of the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are all high-order even aspherical surfaces.

9. The wide-angle, low-distortion optical imaging lens according to claim 1, wherein: The object side surface of the seventh lens is concave near the optical axis, and the image side surface of the eighth lens is convex near the optical axis.

Images