An ultra-wide-angle lens

Abstract

The application discloses an ultra-wide-angle lens, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in sequence along an optical axis from an object side to an image side; in the direction from the object side to the image side, the first lens is a convex-concave lens with negative focal power, the second lens is a concave-concave lens with negative focal power, the third lens is a convex-convex lens with positive focal power, the fourth lens is a concave-convex lens with negative focal power, the fifth lens is a convex-convex lens with positive focal power, the sixth lens is a concave-concave lens with negative focal power, the seventh lens is a convex-convex lens with positive focal power, and the eighth lens is a concave-concave lens with negative focal power. Thus, the field angle of the ultra-wide-angle lens is 200°, the maximum can match a 1 / 2.3" target surface sensor chip, and the ultra-wide-angle lens has the characteristics of a large field angle, a short total length and low cost.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and more particularly to an ultra-wide-angle lens. Background Technology

[0002] As the market demands increasingly stringent specifications and performance from lenses, wide-angle lenses, due to their ability to provide a wider field of view, are widely used in industries such as surveillance, photography, and automotive. To achieve this broader field of view, lenses require increasingly larger field-of-view angles, leading to increased costs. Therefore, reducing costs and improving resolution while maintaining the desired field of view has become a key challenge in lens design. Summary of the Invention

[0003] This invention provides an ultra-wide-angle lens, which is a fixed-focus lens with a field of view of 200°. It can be matched with a 1 / 2.3″ target surface sensor chip and has the characteristics of large field of view, short overall length and low cost.

[0004] To achieve the above objectives, embodiments of the present invention provide an ultra-wide-angle lens, comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged sequentially along the optical axis from the object side to the image side;

[0005] Along the object-to-image direction, the first lens is a negative optical power convex-concave lens, the second lens is a negative optical power concave-concave lens, the third lens is a positive optical power convex-convex lens, the fourth lens is a negative optical power concave-convex lens, the fifth lens is a positive optical power convex-convex lens, the sixth lens is a negative optical power concave-concave lens, the seventh lens is a positive optical power convex-convex lens, and the eighth lens is a negative optical power concave-concave lens.

[0006] Optionally, the optical power of the ultra-wide-angle lens is φ, the optical power of the first lens is φ1, the optical power of the second lens is φ2, the optical power of the third lens is φ3, the optical power of the fourth lens is φ4, the optical power of the fifth lens is φ5, the optical power of the sixth lens is φ6, the optical power of the seventh lens is φ7, and the optical power of the eighth lens is φ8.

[0007] Among them, -0.554<φ1 / φ<-0.290; -0.446<φ2 / φ<-0.189;

[0008] 0.358<φ3 / φ<0.579; -0.363<φ4 / φ<-0.150;

[0009] 0.531<φ5 / φ<0.776; -0.420<φ6 / φ<-0.129;

[0010] 0.423<φ7 / φ<0.704; -0.575<φ8 / φ<-0.308.

[0011] Optionally, the refractive index of the first lens is n1, the refractive index of the second lens is n2, the refractive index of the third lens is n3, the refractive index of the fourth lens is n4, the refractive index of the fifth lens is n5, the refractive index of the sixth lens is n6, the refractive index of the seventh lens is n7, and the refractive index of the eighth lens is n8.

[0012] Wherein, 1.72≤n1≤1.87; 1.45≤n2≤1.59; 1.57≤n3≤1.69;

[0013] 1.55≤n4≤1.69; 1.59≤n5≤1.69; 1.59≤n6≤1.79; 1.48≤n7≤1.60; 1.59≤n8≤1.69;

[0014] Optionally, the dispersion coefficient of the first lens is v1, the dispersion coefficient of the second lens is v2, the dispersion coefficient of the third lens is v3, the dispersion coefficient of the fourth lens is v4, the dispersion coefficient of the fifth lens is v5, the dispersion coefficient of the sixth lens is v6, the dispersion coefficient of the seventh lens is v7, and the dispersion coefficient of the eighth lens is v8.

[0015] Among them, 60.47≤v1≤66.00; 61.94≤v2≤66.00; 25.76≤v3≤28.58;

[0016] 19.00≤v4≤21.03;59.78≤v5≤66.00;24.96≤v6≤27.41;

[0017] 41.78≤v7≤52.90;19.46≤v8≤24.06;

[0018] Optionally, φ1 / φ=-0.393; φ2 / φ=-0.346; φ3 / φ=0.477; φ4 / φ=-0.263; φ5 / φ=0.636; φ6 / φ=-0.229; φ7 / φ=0.532; φ8 / φ=-0.412; n1=1.80; n2=1.54; n3= 1.64; n4=1.64; n5=1.64; n6=1.64; n7=1.54; n8=1.64; v1=61.47; v2=6 2.94; v3=27.57; v4=20.00; v5=60.78; v6=25.96; v7=51.90; v8=21.77.

[0019] Optionally, φ1 / φ=-0.454; φ2 / φ=--0.289; φ3 / φ=0.479; φ4 / φ=-0.263; φ5 / φ=0 .631; φ6 / φ=-0.234; φ7 / φ=0.523; φ8 / φ=-0.408; n1=1.82; n2=1.52; n3= 1.64; n4=1.64; n5=1.64; n6=1.64; n7=1.53; n8=1.64; v1=64.89; v2=6 5.00; v3=27.58; v4=20.00; v5=65.00; v6=26.41; v7=51.40; v8=23.06.

[0020] Optionally, φ1 / φ=-0.390; φ2 / φ=-0.333; φ3 / φ=0.458; φ4 / φ=-0.250; φ5 / φ=0.676; φ6 / φ=-0.320; φ7 / φ=0.604; φ8 / φ=-0.475; n1=1.77; n2=1.50; n3= 1.62; n4=1.60; n5=1.64; n6=1.74; n7=1.55; n8=1.64; v1=65.00; v2=6 3.84; v3=26.76; v4=20.03; v5=65.00; v6=26.10; v7=42.78; v8=20.46.

[0021] Optionally, the image plane diameter IC and total length TTL of the ultra-wide-angle lens satisfy IC / TTL≥0.35.

[0022] Optionally, the aperture of the ultra-wide-angle lens is F=2.0.

[0023] Optionally, the first lens and the fifth lens are glass spherical mirrors, and the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens and the eighth lens are all plastic aspherical mirrors.

[0024] The ultra-wide-angle lens proposed in this embodiment of the invention includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged sequentially along the optical axis from the object side to the image side; in the direction from the object side to the image side, the first lens is a convex-concave lens with negative optical power, the second lens is a concave-concave lens with negative optical power, the third lens is a convex-convex lens with positive optical power, the fourth lens is a concave-convex lens with negative optical power, the fifth lens is a convex-convex lens with positive optical power, the sixth lens is a concave-concave lens with negative optical power, the seventh lens is a convex-convex lens with positive optical power, and the eighth lens is a concave-concave lens with negative optical power. Therefore, by setting a suitable optical power, aberrations can be reduced, sensitivity can be lowered, and light can be allowed to propagate smoothly; and by setting the shape of the corresponding lenses, a wide-angle lens can be obtained. Thus, the ultra-wide-angle lens has a field of view of 200°, can be matched with a 1 / 2.3″ target surface sensor chip, and has the characteristics of a large field of view, short overall length, and low cost.

[0025] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the ultra-wide-angle lens provided in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the ultra-wide-angle lens provided in Embodiment 1 of the present invention;

[0029] Figure 3 for Figure 2 A schematic diagram of the axial aberration curve of the ultra-wide-angle lens is shown.

[0030] Figure 4 for Figure 2 A schematic diagram of the vertical chromatic aberration curve of the ultra-wide-angle lens shown.

[0031] Figure 5 This is a schematic diagram of the structure of the ultra-wide-angle lens provided in Embodiment 2 of the present invention;

[0032] Figure 6 for Figure 5 A schematic diagram of the axial aberration curve of the ultra-wide-angle lens is shown.

[0033] Figure 7 for Figure 5 A schematic diagram of the vertical chromatic aberration curve of the ultra-wide-angle lens shown.

[0034] Figure 8 This is a schematic diagram of the structure of the ultra-wide-angle lens provided in Embodiment 3 of the present invention;

[0035] Figure 9 for Figure 8 A schematic diagram of the axial aberration curve of the ultra-wide-angle lens is shown.

[0036] Figure 10 for Figure 8 The diagram shows the vertical chromatic aberration curve of the ultra-wide-angle lens. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0039] Figure 1 This is a schematic diagram of the structure of an ultra-wide-angle lens provided in an embodiment of the present invention. Figure 1 As shown, the ultra-wide-angle lens includes: a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, and an eighth lens 8 arranged sequentially along the optical axis from the object side to the image side;

[0040] Along the object-to-image direction, the first lens 1 is a convex-concave lens with negative optical power, the second lens 2 is a concave-concave lens with negative optical power, the third lens 3 is a convex-convex lens with positive optical power, the fourth lens 4 is a concave-convex lens with negative optical power, the fifth lens 5 is a convex-convex lens with positive optical power, the sixth lens 6 is a concave-concave lens with negative optical power, the seventh lens 7 is a convex-convex lens with positive optical power, and the eighth lens 8 is a concave-concave lens with negative optical power.

[0041] By matching the optical power of the first lens 1 to the eighth lens 8 in the pattern of "negative-negative-positive-negative-positive-negative-positive-negative", the optical power of each lens can be reasonably allocated, which can reduce aberrations, lower sensitivity, and enable light to propagate smoothly.

[0042] It is understood that the object-side surface of the first lens 1 is convex and the image-side surface is concave; the object-side surface of the second lens 2 is concave and the image-side surface is concave; the object-side surface of the third lens 3 is convex and the image-side surface is convex; the object-side surface of the fourth lens 4 is concave and the image-side surface is convex; the object-side surface of the fifth lens 5 is convex and the image-side surface is convex; the object-side surface of the sixth lens 6 is concave and the image-side surface is concave; the object-side surface of the seventh lens 7 is convex and the image-side surface is convex; and the object-side surface of the eighth lens 8 is concave and the image-side surface is concave. Here, a convex surface refers to a surface of the lens that protrudes towards the object side or the surface of the lens that protrudes towards the image side; a concave surface refers to a surface of the lens that protrudes towards the image side or the surface of the lens that protrudes towards the object side.

[0043] The first lens 1, with its convex-concave shape and small thickness ratio, is easy to manufacture and facilitates light collection, ensuring a wide field of view for the fixed-focus lens. The second lens 2 corrects astigmatism and balances aberrations. The third lens 3, the fourth lens 4, the sixth lens 6, and the seventh lens 7 are cemented doublets, which improve the performance of the optical system and, when combined, reduce chromatic aberration. The eighth lens 8, a biconcave aspherical surface, can change the angle at which light enters the sensor to better match the sensor's CRA (Chief Ray Angel).

[0044] Therefore, by setting the shape of the corresponding lens, the light can be prevented from being excessively deflected on a certain surface, and aberrations can be corrected to improve image quality, resulting in a lens with a large field of view.

[0045] Optionally, the optical power of the ultra-wide-angle lens is φ, the optical power of the first lens 1 is φ1, the optical power of the second lens 2 is φ2, the optical power of the third lens 3 is φ3, the optical power of the fourth lens 4 is φ4, the optical power of the fifth lens 5 is φ5, the optical power of the sixth lens 6 is φ6, the optical power of the seventh lens 7 is φ7, and the optical power of the eighth lens 8 is φ8.

[0046] Among them, -0.554<φ1 / φ<-0.290; -0.446<φ2 / φ<-0.189;

[0047] 0.358<φ3 / φ<0.579; -0.363<φ4 / φ<-0.150;

[0048] 0.531<φ5 / φ<0.776; -0.420<φ6 / φ<-0.129;

[0049] 0.423<φ7 / φ<0.704; -0.575<φ8 / φ<-0.308.

[0050] Optionally, the refractive index of the first lens 1 is n1, the refractive index of the second lens 2 is n2, the refractive index of the third lens 3 is n3, the refractive index of the fourth lens 4 is n4, the refractive index of the fifth lens 5 is n5, the refractive index of the sixth lens 6 is n6, the refractive index of the seventh lens 7 is n7, and the refractive index of the eighth lens 8 is n8.

[0051] Wherein, 1.72≤n1≤1.87; 1.45≤n2≤1.59; 1.57≤n3≤1.69;

[0052] 1.55≤n4≤1.69; 1.59≤n5≤1.69; 1.59≤n6≤1.79; 1.48≤n7≤1.60; 1.59≤n8≤1.69;

[0053] Optionally, the dispersion coefficient of the first lens is v1, the dispersion coefficient of the second lens is v2, the dispersion coefficient of the third lens is v3, the dispersion coefficient of the fourth lens is v4, the dispersion coefficient of the fifth lens is v5, the dispersion coefficient of the sixth lens is v6, the dispersion coefficient of the seventh lens is v7, and the dispersion coefficient of the eighth lens is v8.

[0054] Among them, 60.47≤v1≤66.00; 61.94≤v2≤66.00; 25.76≤v3≤28.58;

[0055] 19.00≤v4≤21.03;59.78≤v5≤66.00;24.96≤v6≤27.41;

[0056] 41.78≤v7≤52.90;19.46≤v8≤24.06;

[0057] Therefore, by properly allocating the optical power of the lens and matching it with a suitable refractive index and dispersion coefficient, system aberrations can be corrected.

[0058] Optionally, the image plane diameter IC and total length TTL of the ultra-wide-angle lens satisfy IC / TTL≥0.35, indicating that the lens has a large target area.

[0059] Optionally, the aperture of the ultra-wide-angle lens is F=2.0.

[0060] Optionally, the first lens 1 and the fifth lens 5 are glass spherical mirrors, while 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 plastic aspherical mirrors. The combination of glass and plastic is lower in cost than all-glass lenses and more stable in performance than all-plastic lenses.

[0061] Optionally, the ultra-wide-angle lens also includes an aperture stop STO located between the fourth lens 4 and the fifth lens 5. It also includes a flat glass plate 9 and an image acquisition unit 10.

[0062] The following describes the ultra-wide-angle lens proposed in the embodiments of the present invention using specific examples.

[0063] Example 1

[0064] Figure 2 This is a schematic diagram of the structure of the ultra-wide-angle lens provided in Embodiment 1 of the present invention. Figure 2 As shown, the ultra-wide-angle lens includes: a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, an aperture stop STO, a fifth lens 15, a sixth lens 16, a seventh lens 17, and an eighth lens 18 arranged sequentially along the optical axis from the object side to the image side; in the direction from the object side to the image side, the first lens 11 is a negative optical power convex-concave glass spherical lens, the second lens 12 is a negative optical power concave-concave plastic aspherical lens, the third lens 13 is a positive optical power convex-convex plastic aspherical lens, the fourth lens 14 is a negative optical power concave-convex plastic aspherical lens, the fifth lens 15 is a positive optical power convex-convex glass spherical lens, the sixth lens 16 is a negative optical power concave-concave plastic aspherical lens, the seventh lens 17 is a positive optical power convex-convex plastic aspherical lens, and the eighth lens 18 is a negative optical power concave-concave plastic aspherical lens.

[0065] Among them, the optical power of the ultra-wide-angle lens is φ, the optical power of the first lens 1 is φ1, the refractive index is n1, and the dispersion coefficient is v1; the optical power of the second lens 2 is φ2, the refractive index is n2, and the dispersion coefficient is v2; the optical power of the third lens 3 is φ3, the refractive index is n3, and the dispersion coefficient is v3; the optical power of the fourth lens 4 is φ4, the refractive index is n4, and the dispersion coefficient is v4; the optical power of the fifth lens 5 is φ5, the refractive index is n5, and the dispersion coefficient is v5; the optical power of the sixth lens 6 is φ6, the refractive index is n6, and the dispersion coefficient is v6; the optical power of the seventh lens 7 is φ7, the refractive index is n7, and the dispersion coefficient is v7; and the optical power of the eighth lens 8 is φ8, the refractive index is n8, and the dispersion coefficient is v8.

[0066] Among them, φ1 / φ=-0.393; φ2 / φ=-0.346; φ3 / φ=0.477; φ4 / φ=-0.263; φ5 / φ=0.636; φ6 / φ=-0.229; φ7 / φ=0.532; φ8 / φ=-0.412; n1=1.80; n2=1.54; n3=1 .64; n4=1.64; n5=1.64; n6=1.64; n7=1.54; n8=1.64; v1=61.47; v2=62 .94; v3=27.57; v4=20.00; v5=60.78; v6=25.96; v7=51.90; v8=21.77.

[0067] The ultra-wide-angle lens in Example 1 has a focal length of 2.246mm and an aperture of F2.0.

[0068] Field of view: 200° Total optical length: 17mm.

[0069] The aspherical conic coefficient of the ultra-wide-angle lens in this invention can be defined by the following aspherical formula, but is not limited to the following representation:

[0070]

[0071] Where Z is the sag of the aspherical surface, c is the fundamental curvature at the vertex, k is the conic section constant, r is the radial coordinate perpendicular to the optical axis, and a i a is the coefficient of the higher-order term. i r 2i For aspherical surfaces, the term is of higher order.

[0072] In this embodiment, the optical physical parameters of the first lens 11 to the eighth lens 18 are as follows:

[0073] Table 1 Design values ​​for the ultra-wide-angle lens in Example 1

[0074]

[0075]

[0076] The surface number is determined by the order of the lenses. For example, surface number "S1" represents the object side of the first lens, surface number "S2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature (mm) represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image side, and a negative value means that the surface bends towards the image side with the center closer to the object side. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness (mm) represents the axial distance between the center of the current surface and the next surface. Due to the different number of digits of each parameter, there may be focusing errors. Therefore, the thickness of the 19th surface is not given a specific value. The value can be adjusted as needed to achieve a clear focus. The material (nd) represents the refractive index, which is the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air with a refractive index of 1. The material (vd) represents the Abbe number (dispersion coefficient), which is the dispersion characteristic of the material between the current surface and the next surface. A blank space indicates that the current position is air. Half diameter (mm) represents the half diameter of the lens.

[0077] Table 2 Aspherical coefficients of the ultra-wide-angle lens in Example 1

[0078]

[0079] Figure 3 for Figure 2 The diagram shows the axial aberration curves of an ultra-wide-angle lens. The vertical direction represents the normalized aperture, with 0 indicating on the optical axis. The vertical vertex represents the maximum pupil radius. The horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 3 It can be seen that the axial aberrations of different wavelengths are all controlled within the range of (-0.01mm, +0.02mm), indicating that the spherical aberration of the ultra-wide-angle lens is well controlled at each wavelength.

[0080] Figure 4 for Figure 2 The diagram shows the transverse chromatic aberration curve of the ultra-wide-angle lens. The vertical direction represents the normalized field of view, with 0 indicating the optical axis, and the vertical vertex representing the maximum field of view radius. The horizontal direction represents the offset within a 0.588μm meridian, in micrometers (μm). The numbers on the curves represent the wavelengths they correspond to, in micrometers (μm). As can be seen from the diagram, the transverse chromatic aberration can be controlled within the range of -0.5μm to 3.1μm, indicating that the ultra-wide-angle lens achieves good control over transverse chromatic aberration at various wavelengths.

[0081] Example 2

[0082] Figure 5This is a schematic diagram of the structure of the ultra-wide-angle lens provided in Embodiment 2 of the present invention. Figure 5 As shown, the ultra-wide-angle lens includes: a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, an aperture stop 20, a fifth lens 25, a sixth lens 26, a seventh lens 27, and an eighth lens 28 arranged sequentially from the object side to the image side along the optical axis; a flat glass plate 29; and an image acquisition unit 210. Along the direction from the object side to the image side, the first lens 21 is a negative power convex-concave glass spherical lens, the second lens 22 is a negative power concave-concave plastic aspherical lens, the third lens 23 is a positive power convex-convex plastic aspherical lens, the fourth lens 24 is a negative power concave-convex plastic aspherical lens, the fifth lens 25 is a positive power convex-convex glass spherical lens, the sixth lens 26 is a negative power concave-concave plastic aspherical lens, the seventh lens 27 is a positive power convex-convex plastic aspherical lens, and the eighth lens 28 is a negative power concave-concave plastic aspherical lens.

[0083] Among them, the optical power of the ultra-wide-angle lens is φ, the optical power of the first lens 21 is φ1, the refractive index is n1, and the dispersion coefficient is v1; the optical power of the second lens 22 is φ2, the refractive index is n2, and the dispersion coefficient is v2; the optical power of the third lens 23 is φ3, the refractive index is n3, and the dispersion coefficient is v3; the optical power of the fourth lens 24 is φ4, the refractive index is n4, and the dispersion coefficient is v4; the optical power of the fifth lens 25 is φ5, the refractive index is n5, and the dispersion coefficient is v5; the optical power of the sixth lens 26 is φ6, the refractive index is n6, and the dispersion coefficient is v6; the optical power of the seventh lens 27 is φ7, the refractive index is n7, and the dispersion coefficient is v7; and the optical power of the eighth lens 28 is φ8, the refractive index is n8, and the dispersion coefficient is v8.

[0084] Among them, φ1 / φ=-0.454; φ2 / φ=--0.289; φ3 / φ=0.479; φ4 / φ=-0.263; φ5 / φ=0.631; φ6 / φ=-0.234; φ7 / φ=0.523; φ8 / φ=-0.408; n1=1.82; n2=1.52; n3= 1.64; n4=1.64; n5=1.64; n6=1.64; n7=1.53; n8=1.64; v1=64.89; v2=6 5.00; v3=27.58; v4=20.00; v5=65.00; v6=26.41; v7=51.40; v8=23.06.

[0085] The ultra-wide-angle lens in Example 2 has a focal length of 2.236mm and an aperture of F2.0.

[0086] Field of view: 200°; Total optical length: 16.66mm.

[0087] The aspherical conic coefficient of the ultra-wide-angle lens in this invention can be defined by the following aspherical formula, but is not limited to the following representation:

[0088]

[0089] Where Z is the sag of the aspherical surface, c is the fundamental curvature at the vertex, k is the conic section constant, r is the radial coordinate perpendicular to the optical axis, and a i a is the coefficient of the higher-order term. i r 2i For aspherical surfaces, the term is of higher order.

[0090] In this embodiment, the optical physical parameters of the first lens 21 to the eighth lens 28 are as follows:

[0091] Table 3 Design values ​​for the ultra-wide-angle lens in Example 2

[0092] Face number Surface type radius of curvature thickness Materials (nd) Materials (vd) Half diameter S1 spherical 14.199 1.650 1.82 64.89 6.001 S2 spherical 2.981 2.246 2.733 S3 aspherical -9.112 0.977 1.52 65.00 2.640 S4 aspherical 7.552 0.150 2.055 S5 aspherical 14.680 1.107 1.64 27.58 1.999 S6 aspherical -3.645 0.238 1.727 S7 aspherical -4.120 2.392 1.64 20.00 1.500 S8 aspherical -21.274 0.508 1.419 STO spherical unlimited -0.250 1.430 S10 spherical 3.963 1.322 1.64 65.00 1.438 S11 spherical -4.610 0.147 1.493 S12 aspherical -29.171 0.801 1.64 26.41 1.485 S13 aspherical 7.863 0.231 1.549 S14 aspherical 10.157 1.556 1.53 51.40 1.624 S15 aspherical -2.782 0.230 1.700 S16 aspherical -20.341 0.779 1.64 23.06 1.803 S17 aspherical 4.271 1.000 2.207 S18 spherical PL 0.610 1.52 64.20 2.583 S19 spherical PL Focus as needed 2.742

[0093] The surface number is determined by the order of the lenses. For example, surface number "S1" represents the object side of the first lens, surface number "S2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature (mm) represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image side, and a negative value means that the surface bends towards the image side with the center closer to the object side. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness (mm) represents the axial distance between the center of the current surface and the next surface. Due to the different number of digits of each parameter, there may be focusing errors. Therefore, the thickness of the 19th surface is not given a specific value. The value can be adjusted as needed to achieve a clear focus. The material (nd) represents the refractive index, which is the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air with a refractive index of 1. The material (vd) represents the Abbe number (dispersion coefficient), which is the dispersion characteristic of the material between the current surface and the next surface. A blank space indicates that the current position is air. Half diameter (mm) represents the half diameter of the lens.

[0094] Table 4 Aspherical coefficients of the ultra-wide-angle lens in Example 2

[0095]

[0096] Figure 6 for Figure 5 The diagram shows the axial aberration curves of an ultra-wide-angle lens. The vertical direction represents the normalized aperture, with 0 indicating on the optical axis. The vertical vertex represents the maximum pupil radius. The horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 6It can be seen that the axial aberrations of different wavelengths are all controlled within the range of (-0.005mm, +0.015mm), indicating that the spherical aberration of the ultra-wide-angle lens is well controlled at each wavelength.

[0097] Figure 7 for Figure 5 The diagram shows the transverse chromatic aberration curve of the ultra-wide-angle lens. The vertical direction represents the normalized field of view, with 0 indicating the optical axis, and the vertical vertex representing the maximum field of view radius. The horizontal direction represents the offset within a 0.588μm meridian, in micrometers (μm). The numbers on the curves represent the wavelengths represented by the curves, in micrometers (μm). As can be seen from the diagram, the transverse chromatic aberration can be controlled within the range of (-1.1μm, 2μm), indicating that the ultra-wide-angle lens achieves good control over transverse chromatic aberration at various wavelengths.

[0098] Example 3

[0099] Figure 8 This is a structural schematic diagram of the ultra-wide-angle lens provided in Embodiment 3 of the present invention. Figure 8 As shown, the ultra-wide-angle lens includes: a first lens 31, a second lens 32, a third lens 33, a fourth lens 34, an aperture stop STO, a fifth lens 35, a sixth lens 36, a seventh lens 37, and an eighth lens 38 arranged sequentially from the object side to the image side along the optical axis; a flat glass plate 39; and an image acquisition unit 310. Along the direction from the object side to the image side, the first lens 31 is a negative power convex-concave glass spherical lens, the second lens 32 is a negative power concave-concave plastic aspherical lens, the third lens 33 is a positive power convex-convex plastic aspherical lens, the fourth lens 34 is a negative power concave-convex plastic aspherical lens, the fifth lens 35 is a positive power convex-convex glass spherical lens, the sixth lens 36 is a negative power concave-concave plastic aspherical lens, the seventh lens 37 is a positive power convex-convex plastic aspherical lens, and the eighth lens 38 is a negative power concave-concave plastic aspherical lens.

[0100] Among them, the optical power of the ultra-wide-angle lens is φ, the optical power of the first lens 31 is φ1, the refractive index is n1, and the dispersion coefficient is v1; the optical power of the second lens 32 is φ2, the refractive index is n2, and the dispersion coefficient is v2; the optical power of the third lens 33 is φ3, the refractive index is n3, and the dispersion coefficient is v3; the optical power of the fourth lens 34 is φ4, the refractive index is n4, and the dispersion coefficient is v4; the optical power of the fifth lens 35 is φ5, the refractive index is n5, and the dispersion coefficient is v5; the optical power of the sixth lens 36 is φ6, the refractive index is n6, and the dispersion coefficient is v6; the optical power of the seventh lens 37 is φ7, the refractive index is n7, and the dispersion coefficient is v7; and the optical power of the eighth lens 38 is φ8, the refractive index is n8, and the dispersion coefficient is v8.

[0101] Among them, φ1 / φ=-0.390; φ2 / φ=-0.333; φ3 / φ=0.458; φ4 / φ=-0.250; φ5 / φ=0.676; φ6 / φ=-0.320; φ7 / φ=0.604; φ8 / φ=-0.475; n1=1.77; n2=1.50; n3=1 .62; n4=1.60; n5=1.64; n6=1.74; n7=1.55; n8=1.64; v1=65.00; v2=63 .84; v3=26.76; v4=20.03; v5=65.00; v6=26.10; v7=42.78; v8=20.46.

[0102] The ultra-wide-angle lens in Example 3 has a focal length of 2.372mm and an aperture of F2.0.

[0103] Field of view: 200°; Total optical length: 17mm.

[0104] The aspherical conic coefficient of the ultra-wide-angle lens in this invention can be defined by the following aspherical formula, but is not limited to the following representation:

[0105]

[0106] Where Z is the sag of the aspherical surface, c is the fundamental curvature at the vertex, k is the conic section constant, r is the radial coordinate perpendicular to the optical axis, and a i a is the coefficient of the higher-order term. i r 2i For aspherical surfaces, the term is of higher order.

[0107] In this embodiment, the optical physical parameters of the first lens 31 to the eighth lens 38 are as follows:

[0108] Table 5 Design values ​​for the ultra-wide-angle lens in Example 3

[0109]

[0110]

[0111] The surface number is determined by the order of the lenses. For example, surface number "S1" represents the object side of the first lens, surface number "S2" represents the image side of the first lens, and so on. "STO" represents the aperture stop of the lens. The radius of curvature (mm) represents the curvature of the lens surface. A positive value means that the surface bends towards the object side with the center closer to the image side, and a negative value means that the surface bends towards the image side with the center closer to the object side. "PL" indicates that the surface is flat and the radius of curvature is infinite. The thickness (mm) represents the axial distance between the center of the current surface and the next surface. Due to the different number of digits of each parameter, there may be focusing errors. Therefore, the thickness of the 19th surface is not given a specific value. The value can be adjusted as needed to achieve a clear focus. The material (nd) represents the refractive index, which is the ability of the material between the current surface and the next surface to deflect light. A blank space indicates that the current position is air with a refractive index of 1. The material (vd) represents the Abbe number (dispersion coefficient), which is the dispersion characteristic of the material between the current surface and the next surface. A blank space indicates that the current position is air. Half diameter (mm) represents the half diameter of the lens.

[0112] Table 6 Aspherical coefficients of the ultra-wide-angle lens in Example 3

[0113]

[0114]

[0115] Figure 9 for Figure 8 The diagram shows the axial aberration curves of an ultra-wide-angle lens. The vertical direction represents the normalized aperture, with 0 indicating on the optical axis. The vertical vertex represents the maximum pupil radius. The horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). Different linear curves in the diagram represent different wavelengths of the system's imaging, derived from... Figure 9 It can be seen that the axial aberrations at different wavelengths are all controlled within the range of (-0.005mm, +0.006mm), indicating that the spherical aberration of the ultra-wide-angle lens is well controlled at each wavelength.

[0116] Figure 10 for Figure 8 The diagram shows the transverse chromatic aberration curve of the ultra-wide-angle lens. The vertical direction represents the normalized field of view, with 0 indicating the optical axis, and the vertical vertex representing the maximum field of view radius. The horizontal direction represents the offset within a 0.588μm meridian, in micrometers (μm). The numbers on the curves represent the wavelengths they correspond to, in micrometers (μm). As can be seen from the diagram, the transverse chromatic aberration can be controlled within the range of -1.5μm to 2μm, indicating that the ultra-wide-angle lens achieves good control over transverse chromatic aberration at various wavelengths.

[0117] In summary, the ultra-wide-angle lens proposed in this embodiment of the invention includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged sequentially along the optical axis from the object side to the image side; in the direction from the object side to the image side, the first lens is a convex-concave lens with negative optical power, the second lens is a concave-concave lens with negative optical power, the third lens is a convex-convex lens with positive optical power, the fourth lens is a concave-convex lens with negative optical power, the fifth lens is a convex-convex lens with positive optical power, the sixth lens is a concave-concave lens with negative optical power, the seventh lens is a convex-convex lens with positive optical power, and the eighth lens is a concave-concave lens with negative optical power. Therefore, by setting a suitable optical power, aberrations can be reduced, sensitivity can be lowered, and light can be smoothly propagated; and by setting the shape of the corresponding lenses, a wide-angle lens can be obtained. Thus, the ultra-wide-angle lens has a field of view of 200°, can be matched with a 1 / 2.3″ target surface sensor chip, and has the characteristics of a large field of view, short overall length, and low cost.

[0118] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An ultra-wide-angle lens, characterized in that, include: The first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens are arranged sequentially along the optical axis from the object side to the image side. Along the object-to-image direction, the first lens is a negative optical power convex-concave lens, the second lens is a negative optical power concave-concave lens, the third lens is a positive optical power convex-convex lens, the fourth lens is a negative optical power concave-convex lens, the fifth lens is a positive optical power convex-convex lens, the sixth lens is a negative optical power concave-concave lens, the seventh lens is a positive optical power convex-convex lens, and the eighth lens is a negative optical power concave-concave lens. The optical power of the ultra-wide-angle lens is φ, the optical power of the first lens is φ1, the optical power of the second lens is φ2, the optical power of the third lens is φ3, the optical power of the fourth lens is φ4, the optical power of the fifth lens is φ5, the optical power of the sixth lens is φ6, the optical power of the seventh lens is φ7, and the optical power of the eighth lens is φ8. The first lens has a refractive index of n1, the second lens has a refractive index of n2, the third lens has a refractive index of n3, the fourth lens has a refractive index of n4, the fifth lens has a refractive index of n5, the sixth lens has a refractive index of n6, the seventh lens has a refractive index of n7, and the eighth lens has a refractive index of n8. The dispersion coefficient of the first lens is v1, the dispersion coefficient of the second lens is v2, the dispersion coefficient of the third lens is v3, the dispersion coefficient of the fourth lens is v4, the dispersion coefficient of the fifth lens is v5, the dispersion coefficient of the sixth lens is v6, the dispersion coefficient of the seventh lens is v7, and the dispersion coefficient of the eighth lens is v8. Among them, φ1 / φ=-0.393; φ2 / φ=-0.346; φ3 / φ=0.477; φ4 / φ=-0.263; φ5 / φ=0.636; φ6 / φ=-0.229; φ7 / φ=0.532; φ8 / φ=-0.412; n1=1.80; n2=1.54; n3=1 .64; n4=1.64; n5=1.64; n6=1.64; n7=1.54; n8=1.64; v1=61.47; v2=62 .94; v3=27.57; v4=20.00; v5=60.78; v6=25.96; v7=51.90; v8=21.77; or, φ1 / φ=-0.454; φ2 / φ=-0.289; φ3 / φ=0.479; φ4 / φ=-0.263; φ5 / φ=0.631; φ6 / φ=-0.234; φ7 / φ=0.523; φ8 / φ=-0.408; n1=1.82; n2=1.52; n3=1. 64; n4=1.64; n5=1.64; n6=1.64; n7=1.53; n8=1.64; v1=64.89; v2=65.00; v3=27.58; v4=20.00; v5=65.00; v6=26.41; v7=51.40; v8=23.06; or, φ1 / φ=-0.390; φ2 / φ=-0.333; φ3 / φ=0.458; φ4 / φ=-0.250; φ5 / φ=0.676; φ6 / φ=-0.320; φ7 / φ=0.604; φ8 / φ=-0.475; n1=1.77; n2=1.50; n3=1. 62; n4=1.60; n5=1.64; n6=1.74; n7=1.55; n8=1.64; v1=65.00; v2=63.84; v3=26.76; v4=20.03; v5=65.00; v6=26.10; v7=42.78; v8=20.46; The ultra-wide-angle lens has eight lenses with optical power.

2. The ultra-wide-angle lens according to claim 1, characterized in that, The ultra-wide-angle lens has an aperture of F=2.

0.

3. The ultra-wide-angle lens according to any one of claims 1-2, characterized in that, The first lens and the fifth lens are glass spherical mirrors, while the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens are all plastic aspherical mirrors.

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