A low-distortion optical imaging lens

Abstract

The present invention relates to the field of lens technology. The present invention discloses a low-distortion optical imaging lens, which includes, from the object side to the image side, a first lens to an eighth lens in sequence along an optical axis; the first lens is a convex-concave lens with a positive refractive power, the second lens is a convex-concave lens with a negative refractive power, the third lens and the seventh lens both have a negative refractive power, the fifth lens and the eighth lens are both convex-convex lenses with a positive refractive power, and the sixth lens has a positive refractive power. The first lens and the fifth lens are both made of glass materials, and the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens are all plastic aspheric lenses; the optical imaging lens has only the first to eighth lenses described above with a refractive power. The present invention has the advantages of small size, low cost, large light transmission, low 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 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, tablet computers, vehicle-mounted 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, existing optical imaging lenses used 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 transmission 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 lens imaging quality is poor and cannot meet the needs of high-definition imaging, etc. Therefore, it is necessary to improve them to meet the increasingly high demands of consumers. Summary of the Invention

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

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

[0006] Furthermore, it also includes an aperture, which is arranged between the fourth lens and the fifth lens.

[0007] Furthermore, the optical imaging lens further satisfies: 25.00mm < |f1| < 90.00mm, 5.50mm < |f2| < 8.00mm, 12.00mm < |f3| < 22.00mm, 10.00mm < |f4| < 260.00mm, 7.00mm < |f5| < 11.00mm, 5.50mm < |f6| < 8.50mm, 6.00mm < |f7| < 11.00mm, 7.00mm < |f8| < 9.50mm, where f1, f2, f3, f4, f5, f6, f7, and f8 are the focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens, respectively.

[0008] [[ID=​​​​​​​​​​​​​​​​

[0014] Furthermore, the object-side surface of the sixth lens is concave, and the image-side surface of the sixth lens is convex.

[0015] Beneficial technical effects of the present invention:

[0016] The present invention adopts a design combining eight lenses, two glass lenses and six plastic aspheric lenses, and by designing each lens accordingly, it has the advantages of small overall lens size and low cost; large light transmission, high brightness, and good imaging quality even in darker environments; better distortion control, good imaging quality, and reduced difficulty in later correction; good lens image quality and high clarity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

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

[0019] Figure 2 This is the MTF diagram of Example 1 of the present invention under visible light 435-650nm;

[0020] Figure 3 This is a defocus curve diagram of 60 lp / mm under visible light 435-650nm in Example 1 of the present invention;

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

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

[0023] Figure 6 This 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 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 This is a graph showing the field curvature and distortion curves of Example 3 of the present invention under visible light of 435nm-650nm;

[0036] Figure 19 This is a structural diagram of a fourth embodiment of the present invention;

[0037] Figure 20 This is the MTF diagram of Example 4 of the present invention under visible light 435-650nm;

[0038] Figure 21 This is a defocus curve diagram of 60 lp / mm under visible light 435-650nm of Example 4 of the present invention;

[0039] Figure 22 This is a lateral chromatic aberration curve of Example 4 of the present invention under visible light 435nm-650nm;

[0040] Figure 23 This is a longitudinal chromatic aberration curve of Example 4 of the present invention under visible light 435nm-650nm;

[0041] Figure 24 This is a graph showing the field curvature and distortion curves of Example 4 of the present invention under visible light of 435nm-650nm;

[0042] Figure 25 This is a structural diagram of Embodiment 5 of the present invention;

[0043] Figure 26 This is the MTF diagram of Example 5 of the present invention under visible light 435-650nm;

[0044] Figure 27 This is a defocus curve diagram of 60 lp / mm under visible light 435-650nm of Example 5 of the present invention;

[0045] Figure 28 This is a lateral chromatic aberration curve of Example 5 of the present invention under visible light 435nm-650nm;

[0046] Figure 29 This is a longitudinal chromatic aberration curve of Example 5 of the present invention under visible light 435nm-650nm;

[0047] Figure 30 Graph showing field curvature and distortion of the fifth embodiment of the present invention under visible light ranging from 435 nm to 650 nm. DETAILED DESCRIPTION

[0048] 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.

[0049] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0050] "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.

[0051] The present invention discloses a low-distortion optical imaging lens, which includes, from the object side to the image side, a first lens to an eighth lens in sequence along an optical axis; the first lens to the eighth lens each include 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 positive 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 fifth lens has a positive refractive power, the object-side surface of the fifth lens is a convex surface, and the image-side surface of the fifth lens is a convex surface; the sixth lens has a positive refractive power; the seventh lens has a negative refractive power; the eighth lens has a positive refractive power, the object-side surface of the eighth lens is a convex surface, and the image-side surface of the eighth lens is a convex surface; the first lens and the fifth lens are both made of glass material, and the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens are all plastic aspheric lenses; the optical imaging lens only includes the first to eighth lenses having refractive powers.

[0052] The present invention adopts a design combining eight lenses, two glass lenses and six plastic aspheric lenses, and through the corresponding design of each lens, has the advantages of small overall lens volume and low cost; large light transmission and high brightness, and good imaging quality even in darker environments; better distortion control and good imaging quality, reducing the difficulty of later correction; good lens image quality and high clarity, achieving 4K imaging clarity.

[0053] Preferably, a stop is further included, which is arranged between the fourth lens and the fifth lens, so that the image side surfaces of the first lens and the second lens are bent toward the stop direction, which is conducive to achieving low distortion of the lens.

[0054] Preferably, the optical imaging lens further satisfies: 25.00mm < |f1| < 90.00mm, 5.50mm < |f2| < 8.00mm, 12.00mm < |f3| < 22.00mm, 10.00mm < |f4| < 260.00mm, 7.00mm < |f5| < 11.00mm, 5.50mm < |f6| < 8.50mm, 6.00mm < |f7| < 11.00mm, 7.00mm < |f8| < 9.50mm, where f1, f2, f3, f4, f5, f6, f7, and f8 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, and the eighth lens respectively, so that the optical power distribution of the lenses is uniform and reasonable, further improving the imaging quality.

[0055] Preferably, the optical imaging lens further satisfies: 6.00 < |f1 / f| < 19.00, 1.00 < |f2 / f| < 2.00, 2.50 < |f3 / f| < 5.00, 2.00 < |f4 / f| < 57.00, 1.00 < |f5 / f| < 3.00, 1.00 < |f6 / f| < 2.00, 1.50 < |f7 / f| < 3.00, 1.00 < |f8 / f| < 2.50, 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, and f8 is the focal length of the eighth lens, so that the optical power distribution of the lenses is uniform and reasonable, further improving the imaging quality.

[0056] Preferably, the optical imaging lens further satisfies: 0.95 ≤ IMH / f ≤ 1.10, 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.

[0057] Preferably, the optical imaging lens further satisfies: nd7 > 1.60, vd7 < 30.00, where nd7 is the refractive index of the seventh lens and vd7 is the dispersion coefficient of the seventh lens, which is beneficial to correcting the chromatic aberration of the system.

[0058] More preferably, the object side of the seventh lens is convex, the image side of the seventh lens is concave, and the cross-section of the seventh lens along its radial direction is in an M-shaped structure, which is beneficial to correcting the chromatic aberration of the system.

[0059] Preferably, the optical imaging lens further satisfies: 4.4mm < f < 4.6mm, TTL < 27.00mm, 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.

[0060] Preferably, the optical imaging lens further satisfies the following requirements: the object-side surfaces and image-side surfaces of the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens are all high-order even-order aspheric surfaces, so as to further correct aberrations and chromatic aberrations and improve imaging quality.

[0061] Preferably, the object-side surface of the sixth lens is concave, and the image-side surface of the sixth lens is convex, which further improves the overall performance.

[0062] The low-distortion optical imaging lens of the present invention will be described in detail below with reference to specific embodiments.

[0063] Example 1

[0064] like Figure 1 As shown, a 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 9, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a protective glass 100, and an imaging surface 110. The first lens 1 to the eighth lens 8 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.

[0065] The first lens element 1 has a positive refractive power. The object-side surface 11 of the first lens element 1 is a convex surface, and the image-side surface 12 of the first lens element 1 is a concave surface.

[0066] 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.

[0067] The third lens element 3 has a negative refractive power. The object-side surface 31 of the third lens element 3 is concave, and the image-side surface 32 of the third lens element 3 is convex.

[0068] The fourth lens element 4 has a negative refractive power. The object-side surface 41 of the fourth lens element 4 is convex, and the image-side surface 42 of the fourth lens element 4 is concave.

[0069] The fifth lens element 5 has a positive refractive power. The object-side surface 51 of the fifth lens element 5 is convex, and the image-side surface 52 of the fifth lens element 5 is convex.

[0070] The sixth lens element 6 has a positive refractive power. The object-side surface 61 of the sixth lens element 6 is concave, and the image-side surface 62 of the sixth lens element 6 is convex.

[0071] The seventh lens element 7 has a negative refractive power. The object-side surface 71 of the seventh lens element 7 is convex, and the image-side surface 72 of the seventh lens element 7 is concave.

[0072] The eighth lens element 8 has a positive refractive power. The object-side surface 81 of the eighth lens element 8 is a convex surface, and the image-side surface 82 of the eighth lens element 8 is a convex surface.

[0073] The first lens 1 and the fifth lens 5 are both made of glass, and the second lens 2, the third lens 3, the fourth lens 4, the sixth lens 6, the seventh lens 7 and the eighth lens 8 are all plastic aspherical lenses.

[0074] In this specific embodiment, the cross section of the seventh lens 7 along its radial direction is substantially in an M-shaped structure.

[0075] In this specific embodiment, the aperture 9 is disposed between the fourth lens 4 and the fifth lens 5 , but is not limited thereto. In other embodiments, the aperture 9 may also be disposed at other appropriate positions.

[0076] The detailed optical data of this specific embodiment are shown in Table 1-1.

[0077] Table 1-1 Detailed optical data of Example 1

[0078]

[0079]

[0080] In this specific embodiment, the object side surface 21, object side surface 31, object side surface 41, object side surface 61, object side surface 71, object side surface 81, image side surface 22, image side surface 32, image side surface 42, image side surface 62, image side surface 72, and image side surface 82 are defined according to the following aspheric curve formula:

[0081]

[0082] in:

[0083] r is the distance from a point on the optical surface to the optical axis.

[0084] z is the sagittal height of the point along the optical axis.

[0085] c is the curvature of the surface.

[0086] k is the quadratic constant of the surface.

[0087] 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.

[0088] Please refer to the table below for detailed parameter data of each aspheric surface:

[0089] Surface number K <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> <![CDATA[A 16 ]]> 21 3.76 2.056E-05 8.940E-05 -5.736E-06 1.937E-08 1.690E-08 -7.998E-10 1.210E-11 22 -0.22 -2.752E-04 -2.872E-04 1.477E-04 -1.364E-05 -2.147E-06 5.065E-07 -2.683E-08 31 3.92 1.201E-02 -1.843E-03 2.481E-04 -2.656E-05 2.019E-06 -1.257E-07 5.671E-09 32 77.27 2.275E-02 -9.593E-03 2.690E-03 -5.805E-04 8.131E-05 -7.088E-06 3.370E-07 41 -16.92 7.987E-03 -6.698E-03 2.193E-03 -5.142E-04 7.703E-05 -7.223E-06 3.636E-07 42 -8.20 2.885E-03 -2.480E-04 2.779E-04 -1.058E-04 3.200E-05 -5.798E-06 3.258E-07 61 5.51 8.678E-03 -9.385E-04 2.326E-04 -4.113E-05 4.278E-06 -2.367E-07 5.758E-09 62 -5.23 -7.371E-03 1.803E-03 -3.523E-04 5.036E-05 -5.104E-06 3.049E-07 -7.086E-09 71 -1.09 -1.883E-02 2.056E-03 -4.442E-04 6.933E-05 -8.414E-06 6.379E-07 -1.990E-08 72 -6.69 -7.841E-03 4.766E-04 -7.190E-05 7.789E-06 -3.021E-07 9.874E-09 -4.125E-10 81 -91.64 7.229E-04 9.288E-04 -2.461E-04 3.450E-05 -2.618E-06 1.023E-07 -1.630E-09 82 -6.81 -3.084E-03 6.481E-04 -9.189E-05 1.285E-05 -1.156E-06 5.183E-08 -8.952E-10

[0090] Please refer to Table 6 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0091] 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 ≤3%.

[0092] In this specific embodiment, the optical imaging lens has a focal length f=4.535 mm; an aperture value FNO=1.8; a field of view FOV=90.0°; 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 110 on the optical axis I=25.26 mm.

[0093] Example 2

[0094] like Figure 7 As shown, the surface profiles, concavities, and refractive powers of the lenses of this embodiment and the first embodiment are substantially the same, except that the refractive power of the fourth lens element 4 is positive, the object-side surface 41 of the fourth lens element 4 is concave, and the image-side surface 42 of the fourth lens element 4 is convex. Furthermore, optical parameters such as the curvature radius of each lens surface and lens thickness are also different.

[0095] The detailed optical data of this specific embodiment are shown in Table 2-1.

[0096] Table 2-1 Detailed optical data of Example 2

[0097] surface Diameter / mm Curvature radius / mm Thickness / interval / mm Material Refractive index dispersion coefficient Focal length / mm object Infinity Infinity 11 First lens 12.933 9.698 2.256 H-ZF13GT 1.79 25.72 82.609 12 10.536 10.221 0.095 21 Second lens 10.275 8.650 1.481 K26R 1.54 55.71 -6.327 22 5.716 2.294 2.795 31 The third lens 5.282 -8.168 2.375 EP8000 1.67 20.38 -12.869 32 4.637 -187.735 0.099 41 Fourth lens 4.578 -61.832 1.681 K26R 1.54 55.71 11.489 42 4.656 -5.666 0.303 9 aperture 4.546 Infinity -0.185 51 Fifth lens 10.400 9.089 2.799 H-LAK6A 1.70 53.35 10.809 52 10.400 -38.109 2.264 61 Sixth lens 5.560 -9.012 1.472 APL5015AL 1.55 56.00 8.110 62 6.119 -3.142 0.174 71 Seventh lens 6.381 12.504 0.960 EP8000 1.67 20.38 -6.946 72 7.202 3.277 0.451 81 Eighth lens 7.755 30.227 3.395 T62R 1.54 55.98 7.598 82 8.359 -4.548 3.374 100 Protective glass 8.933 Infinity 0.700 H-K9L 1.52 64.20 Infinity 8.989 Infinity 0.144 110 Imaging surface 8.856 Infinity 0.000

[0098] Please refer to the following table for detailed parameter data of each aspheric surface in this specific embodiment:

[0099]

[0100]

[0101] Please refer to Table 6 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0102] 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 12 From (A) and (B), we can see that both field curvature and distortion are well corrected, with optical distortion ≤3%.

[0103] In this specific embodiment, the optical imaging lens has a focal length f=4.537 mm; an aperture value FNO=1.8; a field of view FOV=90.0°; 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 110 on the optical axis I=26.63 mm.

[0104] Example 3

[0105] like Figure 13 As shown, the surface profiles, concavities, and refractive powers of the lenses of this embodiment and the first embodiment are substantially the same, except that the refractive power of the fourth lens element 4 is positive, the object-side surface 41 of the fourth lens element 4 is concave, and the image-side surface 42 of the fourth lens element 4 is convex. Furthermore, optical parameters such as the curvature radius of each lens surface and lens thickness are also different.

[0106] The detailed optical data of this specific embodiment are shown in Table 3-1.

[0107] Table 3-1 Detailed optical data of Example 3

[0108]

[0109]

[0110] Please refer to the following table for detailed parameter data of each aspheric surface in this specific embodiment:

[0111] Surface number K <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> <![CDATA[A 16 ]]> 21 -49.77 1.143E-04 8.543E-05 -6.631E-06 2.837E-07 -7.155E-09 9.988E-11 -5.898E-13 22 -0.52 -4.034E-04 -7.791E-04 5.009E-04 -1.201E-04 1.593E-05 -1.050E-06 2.070E-08 31 3.80 9.536E-03 -4.755E-04 -6.834E-05 2.105E-05 -1.480E-06 1.782E-08 1.441E-09 32 23.18 1.688E-02 -2.420E-03 8.186E-04 -4.148E-04 1.279E-04 -1.828E-05 9.045E-07 41 34.78 6.331E-03 -4.052E-03 1.579E-03 -7.282E-04 2.320E-04 -4.155E-05 2.997E-06 42 50.68 1.132E-03 7.740E-05 -4.477E-04 2.316E-04 2.592E-05 -3.555E-05 6.605E-06 61 20.56 6.633E-03 -1.010E-03 2.238E-04 -4.912E-05 5.337E-06 -2.484E-07 4.858E-10 62 -7.45 -8.884E-03 2.100E-03 -4.575E-04 6.000E-05 -6.116E-06 4.297E-07 -1.470E-08 71 -0.80 -1.806E-02 1.432E-03 -2.069E-04 2.668E-05 -2.893E-06 2.716E-07 -1.144E-08 72 -7.66 -5.590E-03 8.988E-05 4.842E-05 -1.301E-05 1.689E-06 -9.177E-08 1.648E-09 81 9.14 1.414E-03 8.695E-04 -2.680E-04 3.501E-05 -2.398E-06 8.562E-08 -1.271E-09 82 -4.72 -2.564E-03 5.282E-04 -8.754E-05 1.300E-05 -1.146E-06 5.082E-08 -8.705E-10

[0112] Please refer to Table 6 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0113] 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 ≤3%.

[0114] In this specific embodiment, the optical imaging lens has a focal length f=4.531 mm; an aperture value FNO=1.8; a field of view FOV=90.0°; 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 110 on the optical axis I=26.52 mm.

[0115] Example 4

[0116] like Figure 19 As shown, the surface profiles, concavities, and refractive powers of the lenses of this embodiment and the first embodiment are substantially the same, except that the refractive power of the fourth lens element 4 is positive, the object-side surface 41 of the fourth lens element 4 is concave, and the image-side surface 42 of the fourth lens element 4 is convex. Furthermore, optical parameters such as the curvature radius of each lens surface and lens thickness are also different.

[0117] The detailed optical data of this specific embodiment are shown in Table 4-1.

[0118] Table 4-1 Detailed optical data of Example 4

[0119] surface Diameter / mm Curvature radius / mm Thickness / interval / mm Material Refractive index dispersion coefficient Focal length / mm object Infinity Infinity 11 First lens 12.768 9.509 2.294 H-ZLAF75A 1.91 31.32 78.900 12 10.277 9.704 0.380 21 Second lens 10.053 11.022 1.511 K26R 1.54 55.71 -5.998 22 5.409 2.374 2.597 31 The third lens 5.080 -8.697 2.864 EP8000 1.67 20.38 -21.400 32 4.913 -25.186 0.099 41 Fourth lens 4.803 -20.862 1.080 K26R 1.54 55.71 18.028 42 4.504 -6.735 0.122 9 aperture 4.295 Infinity -0.003 51 Fifth lens 10.400 8.285 2.800 H-LAK6A 1.70 53.35 10.867 52 10.400 -74.597 2.202 61 Sixth lens 5.695 -19.037 1.957 APL5015AL 1.55 56.00 7.593 62 6.400 -3.529 0.101 71 Seventh lens 6.361 12.093 1.110 EP8000 1.67 20.38 -7.481 72 7.136 3.403 0.314 81 Eighth lens 7.952 27.611 3.129 T62R 1.54 55.98 8.029 82 8.416 -4.926 3.403 100 Protective glass 8.755 Infinity 0.700 H-K9L 1.52 64.20 Infinity 8.793 Infinity 0.144 110 Imaging surface 8.841 Infinity 0.000

[0120] Please refer to the following table for detailed parameter data of each aspheric surface in this specific embodiment:

[0121] Surface number K <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> <![CDATA[A 16 ]]> 21 -26.71 4.771E-05 1.004E-04 -6.859E-06 2.844E-07 -6.965E-09 8.326E-11 1.489E-14 22 -0.58 -3.699E-03 -1.003E-04 3.154E-04 -9.491E-05 1.608E-05 -1.413E-06 4.870E-08 31 8.49 -3.842E-03 3.682E-04 -6.719E-05 1.540E-05 -1.502E-06 8.540E-08 4.986E-09 32 98.99 -2.017E-03 -8.221E-04 8.996E-04 -4.673E-04 1.277E-04 -1.679E-05 8.661E-07 41 70.02 6.709E-03 -1.642E-03 1.595E-03 -8.126E-04 2.182E-04 -2.861E-05 1.484E-06 42 6.00 7.722E-03 3.370E-04 1.488E-04 -1.077E-04 3.635E-05 -5.559E-06 3.583E-07 61 37.54 9.122E-03 -1.297E-03 2.565E-04 -4.807E-05 4.939E-06 -2.655E-07 3.201E-09 62 -9.97 -4.078E-03 1.900E-03 -4.915E-04 6.214E-05 -6.069E-06 3.982E-07 -1.195E-08 71 5.52 -1.554E-02 1.080E-03 -1.834E-04 2.719E-05 -3.223E-06 2.616E-07 -8.383E-09 72 -11.01 -4.607E-03 2.341E-04 3.955E-05 -1.368E-05 1.685E-06 -8.951E-08 1.772E-09 81 28.35 3.730E-03 8.865E-04 -2.766E-04 3.444E-05 -2.382E-06 8.923E-08 -1.408E-09 82 -5.67 -2.409E-03 6.224E-04 -8.889E-05 1.282E-05 -1.149E-06 5.014E-08 -8.368E-10

[0122] Please refer to Table 6 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0123] The MTF curve of this specific embodiment is shown in Figure 20 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 21 , see the lateral chromatic aberration diagram for details. Figure 22 , longitudinal chromatic aberration diagram is shown in Figure 23 , 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 24 From (A) and (B), we can see that both field curvature and distortion are well corrected, with optical distortion ≤3%.

[0124] In this specific embodiment, the optical imaging lens has a focal length f=4.545 mm; an aperture value FNO=1.8; a field of view FOV=90.0°; 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 110 on the optical axis I=26.80 mm.

[0125] Example 5

[0126] like Figure 25As shown, the surface profile and refractive index of each lens in this embodiment are the same as those in the first embodiment, and only the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0127] The detailed optical data of this specific embodiment are shown in Table 5-1.

[0128] Table 5-1 Detailed optical data of Example 5

[0129] surface Diameter / mm Curvature radius / mm Thickness / interval / mm Material Refractive index dispersion coefficient Focal length / mm object Infinity Infinity 11 First lens 15.233 8.751 4.070 H-ZLAF75A 1.91 31.32 68.318 12 10.700 7.931 0.346 21 Second lens 10.312 13.214 0.900 K26R 1.54 55.71 -7.693 22 6.320 3.073 2.382 31 The third lens 5.869 -8.280 0.900 APL5015AL 1.55 56.00 -18.832 32 4.474 -44.049 0.153 41 Fourth lens 4.314 19.734 1.749 EP8000 1.67 20.38 -21.806 42 3.146 8.077 0.234 9 aperture 2.968 Infinity -0.115 51 Fifth lens 10.500 8.899 3.864 H-LAK6A 1.70 53.35 7.568 52 10.500 -10.603 0.100 61 Sixth lens 5.503 -18.948 1.994 APL5015AL 1.55 56.00 6.110 62 5.890 -2.943 0.100 71 Seventh lens 6.000 5.165 1.000 EP8000 1.67 20.38 -10.196 72 7.015 2.708 0.394 81 Eighth lens 8.110 31.823 2.776 T62R 1.54 55.98 9.289 82 8.532 -5.757 3.569 100 Protective glass 8.891 Infinity 0.700 H-K9L 1.52 64.20 Infinity 8.947 Infinity 0.144 110 Imaging surface 8.905 Infinity 0.000

[0130] Please refer to the following table for detailed parameter data of each aspheric surface in this specific embodiment:

[0131]

[0132]

[0133] Please refer to Table 6 for the values ​​of the relevant conditional expressions of this specific embodiment.

[0134] The MTF curve of this specific embodiment is shown in Figure 26 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 27 , see the lateral chromatic aberration diagram for details. Figure 28 , longitudinal chromatic aberration diagram is shown in Figure 29 , 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 30 From (A) and (B), we can see that both field curvature and distortion are well corrected, with optical distortion ≤3%.

[0135] In this specific embodiment, the optical imaging lens has a focal length f=4.535 mm; an aperture value FNO=1.8; a field of view FOV=90.0°; 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 110 on the optical axis I=25.26 mm.

[0136] Table 6 Numerical values ​​of relevant important parameters of five embodiments of the present invention

[0137]

[0138]

[0139] 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 low-distortion optical imaging lens comprising, in order from the object side to the image side along an optical axis, first through eighth lenses; each of the first through eighth 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 element has a positive refractive power, the object side surface of the first lens element is convex, and the image side surface of the first lens element 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 has a negative refractive power; 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; The sixth lens element has a positive refractive power, the object-side surface of the sixth lens element is concave, and the image-side surface of the sixth lens element is convex; The seventh lens element has a negative refractive power, the object-side surface of the seventh lens element is convex, and the image-side surface of the seventh lens element is concave; The eighth lens element has a positive refractive power, the object-side surface of the eighth lens element is convex, and the image-side surface of the eighth lens element is convex; The first lens and the fifth lens are both made of glass, and the second lens, the third lens, the fourth 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 eighth lenses having refractive powers; The optical imaging lens also meets the following requirements: 25.00mm<|f1|<90.00mm, 5.50mm<|f2|<8.00mm, 12.00mm<|f3|<22.00mm, 10.00mm<|f4|<260.00mm, 7.00mm<|f5|<11.00mm, 5.50mm<|f6|<8.50mm, 6.00mm<|f7|<11.00mm, 7.00mm<|f8|<9.50mm, where f1, f2, f3, f4, f5, f6, f7, and f8 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, and the eighth lens, respectively.

2. The low-distortion optical imaging lens according to claim 1, wherein: The optical system further includes an aperture stop disposed between the fourth lens element and the fifth lens element.

3. The low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens further satisfies the following requirements: 6.00<|f1 / f|<19.00, 1.00<|f2 / f|<2.00, 2.50<|f3 / f|<5.00, 2.00<|f4 / f|<57.00, 1.00<|f5 / f|<3.00, 1.00<|f6 / f|<2.00, 1.50<|f7 / f|<3.00, and 1.00<|f8 / f|<2.50, where f is the overall focal length of the optical imaging lens.

4. The low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens further satisfies the following conditions: 0.95≤IMH / f≤1.10, where IMH is the image half-height of the optical imaging lens, and f is the overall focal length of the optical imaging lens.

5. The low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens also satisfies the following conditions: nd7>1.60, vd7<30.00, where nd7 is the refractive index of the seventh lens and vd7 is the dispersion coefficient of the seventh lens.

6. The low-distortion optical imaging lens according to claim 5, wherein: The object-side surface of the seventh lens is convex, the image-side surface of the seventh lens is concave, and the radial cross-section of the seventh lens is M-shaped.

7. The low-distortion optical imaging lens according to claim 1, wherein: The optical imaging lens further satisfies: 4.4 mm < f < 4.6 mm, TTL < 27.00 mm, 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 surface on the optical axis.

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

9. The low-distortion optical imaging lens according to claim 1, wherein: The object side of the sixth lens is concave, and the image side of the sixth lens is convex.

Images