Optical lens

Abstract

The invention provides an optical lens, which comprises eight lenses from an object side to an imaging surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the object side surface and the image side surface of the fourth lens are convex surfaces; the fifth lens has positive focal power, and the image side surface of the fifth lens is a convex surface; the sixth lens has positive focal power, and the image side surface of the sixth lens is a convex surface; the object side surface and the image side surface of the seventh lens are concave surfaces; and the object side surface and the image side surface of the eighth lens are convex surfaces. According to the optical lens provided by the invention, the imaging quality of the optical lens can be improved, the aberration is reduced, and the imaging quality of the optical lens is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an optical lens. Background Art

[0002] As people's requirements for driving experience continue to increase, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[0003] Advanced driver assistance systems (ADAS) play an important role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure the driver's driving safety. In addition to requiring the optical lens to be thin and short and have high pixels and high resolution, the existing ADAS system lens also requires the optical lens to be able to image clearly under low illumination conditions. Therefore, it is necessary to develop an optical lens with good imaging effect. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] An optical lens, comprising eight lenses, which include:

[0007] The first lens has a negative optical power, the object side surface of which is convex, and the image side surface of which is concave;

[0008] The second lens has a negative optical power, its object side surface is concave, and its image side surface is convex;

[0009] The third lens has a negative optical power, its object side surface is convex, and its image side surface is concave;

[0010] The fourth lens has positive refractive power, and both the object side surface and the image side surface are convex;

[0011] a fifth lens element having positive refractive power and a convex image-side surface;

[0012] a sixth lens element having positive refractive power and having a convex image-side surface;

[0013] The seventh lens element has negative optical power, and both the object side surface and the image side surface are concave;

[0014] The eighth lens has positive refractive power, and both the object side surface and the image side surface are convex;

[0015] Among them, the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: -7 < (R3 + R4) / (R3 - R4) < -4.

[0016] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6 < TTL / f < 10.

[0017] Further preferably, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle satisfy: 1.5 < IH / f < 2.3.

[0018] Further preferably, the maximum field of view angle FOV of the optical lens, the effective focal length f of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 50° < (FOV × f) / IH < 65°.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -25 < f2 / f < -9.

[0020] Further preferably, the effective focal length f of the optical lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: -1.6 < f123 / f < -1; the effective focal length f of the optical lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: 1.4 < f45678 / f < 2.2.

[0021] Further preferably, the effective focal length f of the optical lens and the curvature radius R3 of the object side of the second lens satisfy: -2.5 < R3 / f < -1.1; the effective focal length f of the optical lens and the curvature radius R4 of the image side of the second lens satisfy: -3.8 < R4 / f < -1.6.

[0022] Further preferably, the effective focal length f of the optical lens and the curvature radius R5 of the object side of the third lens satisfy: 7.8 < R5 / f < 12.1; the effective focal length f of the optical lens and the curvature radius R8 of the image side of the fourth lens satisfy: -13.7 < R8 / f < -3.3.

[0023] Further preferably, the curvature radius R9 of the object side of the fifth lens and the curvature radius R11 of the object side of the sixth lens satisfy: -5.8 < R9 / R11 < 0; the curvature radius R9 of the object side of the fifth lens and the curvature radius R11 of the object side of the sixth lens satisfy: 1.2 < |(R9 - R11) / (R9 + R11)| < 1.7.

[0024] Further preferably, the sagittal height Sag3 of the clear aperture semi-diameter on the object side of the second lens and the clear aperture semi-diameter d3 on the object side of the second lens satisfy: -0.35 < Sag3 / d3 < -0.15; the sagittal height Sag4 of the clear aperture semi-diameter on the image side of the second lens and the clear aperture semi-diameter d4 on the image side of the second lens satisfy: -0.3 < Sag4 / d4 < -0.1.

[0025] The optical lens provided by the present invention adopts eight lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as a large aperture, a large field of view angle, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0027] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 2 is the field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 3 is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 4 is the lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 5 is the axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0032] Figure 6 is the MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0033] Figure 7 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 8 is the field curvature curve graph of the optical lens in Embodiment 2 of the present invention.

[0035] Fig. 9 is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0036] Fig.10 is the lateral chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0037] Fig.11 Graph showing the axial aberration of the optical lens in Embodiment 2 of the present invention.

[0038] Fig.12 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0039] Fig.13 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0040] Fig.14 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0041] Fig.15 : is the F-Tan (Theta) distortion curve of the optical lens in Example 3 of the present invention.

[0042] Fig.16 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0043] Fig.17 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0044] Fig.18 This is the MTF curve diagram of the optical lens in Example 3 of the present invention.

[0045] Fig.19 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0046] Fig. 20 It is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0047] Fig.21 : is the F-Tan (Theta) distortion curve of the optical lens in Example 4 of the present invention.

[0048] Fig. 22 Graph showing the vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0049] Fig.23 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0050] Fig.24 This is the MTF curve diagram of the optical lens in Example 4 of the present invention.

[0051] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0052] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0053] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0054] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0055] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0056] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0057] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0058] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0059] The optical lens of the embodiment of the present invention has a total of eight lenses, which are: 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 in order from the object side to the imaging surface along the optical axis.

[0060] In some embodiments, the first lens may have a negative optical power, and its object side surface is convex, and its image side surface is concave. The second lens may have a negative optical power, and its object side surface is concave, and its image side surface is convex. The third lens may have a negative optical power, and its object side surface is convex, and its image side surface is concave. The fourth lens may have a positive optical power, and its object side surface and image side surface are both convex. The fifth lens may have a positive optical power, and its object side surface may be concave or convex, and its image side surface is convex. The sixth lens may have a positive optical power, and its object side surface may be concave or convex, and its image side surface is convex. The seventh lens may have a negative optical power, and its object side surface and image side surface are both concave. The eighth lens may have a positive optical power, and its object side surface and image side surface are both convex.

[0061] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the third lens and the fourth lens. It is understood that the aperture is used to limit the amount of light entering to change the brightness of the image. When the aperture is located between the third lens and the fourth lens, it is convenient to correct the aperture aberration.

[0062] In some embodiments, the optical lens may further include a filter, which may be disposed between the eighth lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0063] In some embodiments, the sixth lens and the seventh lens can be glued to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the difficulty of the processing technology of the optical lens and improving the assembly yield of the optical lens.

[0064] In some embodiments, the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: -7<(R3+R4) / (R3-R4)<-4. Meeting the above range can reduce the angle of light deflection and make the light trend more stable; at the same time, it can correct coma and field curvature, improve the flatness of the image, and enhance the imaging quality of the optical lens. More specifically, -6.49<(R3+R4) / (R3-R4)<-4.89.

[0065] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6 < TTL / f < 10. Meeting the above range can effectively limit the length of the lens. More specifically, 6.49 < TTL / f < 9.47.

[0066] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle satisfy: 1.5 < IH / f < 2.3. Meeting the above range ensures that the optical lens has a large imaging surface, improves the lens resolution, and at the same time enables the lens to have a larger field of view angle in the case of a large image surface, which is beneficial to achieving the balance of high pixel and ultra-wide angle of the lens. More specifically, 1.68 < IH / f < 2.02.

[0067] In some embodiments, the maximum field of view angle FOV of the optical lens, the effective focal length f of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 50° < (FOV × f) / IH < 65°. Meeting the above range can balance the needs of large-range detection and high-quality imaging, and improve the adaptability of the optical lens. More specifically, the maximum field of view angle FOV of the optical lens, the effective focal length f of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 56.06° < (FOV × f) / IH < 59.79°.

[0068] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -25 < f2 / f < -9. Meeting the above range can make the second lens have an appropriate negative optical power, share the negative optical power at the front end of the optical lens, which is beneficial to avoiding excessive light deflection caused by overly concentrated optical power of the first lens, and reducing the difficulty of chromatic aberration correction of the optical lens.

[0069] In some embodiments, the effective focal length f of the optical lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: -1.6 < f123 / f < -1; the effective focal length f of the optical lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: 1.4 < f45678 / f < 2.2. Meeting the above range can effectively correct the aberration generated by the lens groups before and after the aperture, and improve the imaging quality of the optical lens. More specifically, -1.48 < f123 / f < -1.14; 1.54 < f45678 / f < 2.02.

[0070] In some embodiments, the effective focal length f of the optical lens and the curvature radius R3 of the object side surface of the second lens satisfy: -2.5 < R3 / f < -1.1; the effective focal length f of the optical lens and the curvature radius R4 of the image side surface of the second lens satisfy: -3.8 < R4 / f < -1.6. Satisfying the above ranges and controlling the surface shape of the second lens can reduce the light deflection angle, make the light path more stable, and improve the imaging quality of the optical lens. More specifically, -2.32 < R3 / f < -1.27; -3.43 < R4 / f < -1.83.

[0071] In some embodiments, the effective focal length f of the optical lens and the curvature radius R5 of the object side surface of the third lens satisfy: 7.8 < R5 / f < 12.1; the effective focal length f of the optical lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -13.7 < R8 / f < -3.3. Satisfying the above ranges is beneficial to slowing down the change degree of the incident light refraction angle and avoiding excessive aberration caused by too strong refraction change. More specifically, 8.59 < R5 / f < 11.07; -12.43 < R8 / f < -3.68.

[0072] In some embodiments, the curvature radius R9 of the object side surface of the fifth lens and the curvature radius R11 of the object side surface of the sixth lens satisfy: -5.8 < R9 / R11 < 0; the curvature radius R9 of the object side surface of the fifth lens and the curvature radius R11 of the object side surface of the sixth lens satisfy: 1.2 < |(R9 - R11) / (R9 + R11)| < 1.7. Satisfying the above ranges is beneficial to obtaining a symmetric surface shape between the object side surface of the fifth lens and the object side surface of the sixth lens, which is beneficial to balancing the coma of the optical lens and improving the imaging quality of the optical lens. More specifically, -5.29 < R9 / R11 < -0.09; 1.31 < |(R9 - R11) / (R9 + R11)| < 1.53.

[0073] In some embodiments, the sagittal height Sag3 of the object side surface clear aperture of the second lens and the object side surface clear aperture d3 of the second lens satisfy: -0.35 < Sag3 / d3 < -0.15; the sagittal height Sag4 of the image side surface clear aperture of the second lens and the image side surface clear aperture d4 of the second lens satisfy: -0.3 < Sag4 / d4 < -0.1. Satisfying the above ranges helps to control the light path of the marginal field of view and highlight the detailed information of the central field of view of the optical lens. More specifically, -0.31 < Sag3 / d3 < -0.2; -0.24 < Sag4 / d4 < -0.15.

[0074] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3.3 < TTL / IH < 5.1. Meeting the above range can better achieve the balance between the total length of the lens and the image plane. More specifically, 3.71 < TTL / IH < 4.72.

[0075] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno satisfy: 60° < FOV / Fno < 80°. Meeting the above requirements is beneficial to expanding the field of view angle of the optical lens and increasing the aperture of the optical lens, which is conducive to the optical lens obtaining more scene information, meeting the needs of large-range detection, and is beneficial to improving the problem that the relative brightness of the edge field of view drops rapidly, and thus is also beneficial to obtaining more scene information. More specifically, 62° < FOV / Fno < 76°.

[0076] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 2.5 < IH / EPD < 3.5. Meeting the above range can increase the width of the light beam incident on the optical lens, so that the brightness of the optical lens at the image plane is improved and vignetting is avoided. More specifically, 2.69 < IH / EPD < 3.22.

[0077] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL satisfy: 0.9 < BFL / f < 1.4. Meeting the above range can make the lens have a long back focus, which is beneficial to the assembly of the module, reduces interference, and improves the production yield. More specifically, 0.98 < BFL / f < 1.26.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.2 < f1 / f < -1.3. Meeting the above range can make the first lens have a negative optical power, which is beneficial to reducing the inclination angle of the incident light, and is beneficial to collecting the edge field of view light into the rear optical lens as much as possible to achieve large-angle light collection. More specifically, -2.09 < f1 / f < -1.52.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -28 < f3 / f < -10. Meeting the above range is beneficial to slowing down the deflection degree of the incident light, avoiding excessive aberration caused by too strong refraction change, and at the same time is beneficial to balancing various aberrations generated by the front lens group and improving the overall imaging quality. More specifically, -24.91 < f3 / f < -11.45.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.2 < f4 / f < 3.5. Meeting the above range can effectively converge light, correct the aberration generated by the front diaphragm lens group, and improve the overall imaging quality. More specifically, 2.44 < f4 / f < 3.19.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.8 < f5 / f < 6.7. Meeting the above range can make the fifth lens have a positive optical power, which is beneficial to improving the light converging ability of the optical lens, and at the same time can balance the aberration of the optical lens and improve the imaging quality of the optical lens. More specifically, 1.94 < f5 / f < 6.03.

[0082] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.4 < f6 / f < 2.4. Meeting the above range can make the sixth lens have a positive optical power, further improve the light converging ability of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens. More specifically, 1.54 < f6 / f < 2.14.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -1.3 < f7 / f < -0.8. Meeting the above range can make the seventh lens have a negative optical power, which is beneficial to increasing the imaging area and field of view angle of the optical lens and improving the imaging quality of the optical lens. More specifically, -1.12 < f7 / f < -0.95.

[0084] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: 1.8 < f8 / f < 5.1. Meeting the above range can make the eighth lens have a positive optical power, control the light trend smoothly, transmit more light to the imaging surface, and improve the imaging quality of the optical lens. More specifically, 2.06 < f8 / f < 4.62.

[0085] In some embodiments, the image-side curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 3.3 < R6 / f < 6.8; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 2.7 < R7 / f < 4.3. Meeting the above range is beneficial to slowing down the change degree of the incident light refraction angle and avoiding excessive aberration caused by too strong refraction change. More specifically, 3.73 < R6 / f < 6.2; 3.08 < R7 / f < 4.

[0086] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 1.9 < (R5 + R6) / (R5 - R6) < 4.1. Satisfying the above range controls the object side surface and the image side surface of the third lens to have reasonable shapes and improves the imaging quality. More specifically, 2.26 < (R5 + R6) / (R5 - R6) < 3.8.

[0087] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: -0.7 < (R7 + R8) / (R7 - R8) < 0.1. Satisfying the above range can effectively correct aberration and improve the imaging quality of the optical lens. More specifically, -0.6 < (R7 + R8) / (R7 - R8) < -0.05.

[0088] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the eighth lens along the optical axis satisfy: 0.5 < ∑CT / TTL < 0.7. Satisfying the above range can compress the total length of the optical system and make the structure of the system more compact. More specifically, 0.51 < ∑CT / TTL < 0.62.

[0089] In some embodiments, the clear aperture radius d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.5 < d1 / (IH / 2) / tan(FOV / 2) < 0.9. Satisfying the above range can balance the relationship between the front port aperture, the field of view angle, and the image plane size of the optical lens, which is beneficial to miniaturization. More specifically, 0.61 < d1 / (IH / 2) / tan(FOV / 2) < 0.79.

[0090] In some embodiments, the optical lens satisfies the conditional formula: 3.6 mm < f < 5.7 mm, 90° < FOV < 130°, 2.3 mm < EPD < 3.6 mm, 28 mm < TTL < 40 mm, 1.4 < Fno < 1.8, 7.5 mm < IH < 9.5 mm, 5.9° < CRA < 18.2°, 4.5 mm < BFL < 6 mm, where f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the image height corresponding to the maximum field of view angle of the optical lens, CRA represents the principal ray incident angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least the characteristics of a large field of view angle, a large image plane, and a large aperture. More specifically, 4.01 mm < f < 5.25 mm, 99° < FOV < 121°, 2.5 mm < EPD < 3.28 mm, 29 mm < TTL < 39 mm, 1.5 < Fno < 1.7, 8.05 mm < IH < 8.86 mm, 6.54° < CRA < 16.85°, 5.02 mm < BFL < 5.5 mm.

[0091] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0092] In some embodiments, 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 can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the fourth lens, the sixth lens, and the seventh lens of the present invention adopt spherical lenses, and the third lens, the fifth lens, and the eighth lens adopt aspherical lenses.

[0093] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0094]

[0095] Among them, z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0096] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0097] Example 1

[0098] See also Figure 1 , which is a schematic diagram of the structure of the optical lens provided in Embodiment 1 of the present invention, wherein the optical lens includes, in sequence from the object side to the imaging surface along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0099] The first lens L1 has negative refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0100] The second lens L2 has negative refractive power, its object side surface S3 is concave, and its image side surface S4 is convex;

[0101] The third lens L3 has negative refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0102] The fourth lens L4 has positive refractive power, and its object-side surface S7 and image-side surface S8 are both convex surfaces;

[0103] The fifth lens L5 has positive refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0104] The sixth lens L6 has positive refractive power, and its object-side surface S11 and image-side surface S12 are both convex surfaces;

[0105] The seventh lens L7 has negative refractive power, and its object-side surface S12 and image-side surface S13 are both concave;

[0106] The sixth lens L6 and the seventh lens L7 form a cemented lens group with negative refractive power, that is, the cemented surface between the image side surface of the sixth lens L6 and the object side surface of the seventh lens L7 is S12;

[0107] The eighth lens L8 has positive refractive power, and its object-side surface S14 and image-side surface S15 are both convex surfaces;

[0108] The object side surface S16 and the image side surface S17 of the filter G1 are both planes;

[0109] The imaging surface S18 is a plane.

[0110] The first lens, the second lens, the fourth lens, the sixth lens and the seventh lens are glass spherical lenses, and the third lens, the fifth lens and the eighth lens are glass aspherical lenses.

[0111] The relevant parameters of each lens in the optical lens in Example 1 are shown in Table 1-1.

[0112] Table 1-1

[0113]

[0114]

[0115] The surface parameters of the aspherical lens of the optical lens in Example 1 are shown in Table 1-2.

[0116] Table 1-2

[0117] Face number K B C D E F G H S5 6.81E+01 4.60E-05 -3.86E-06 1.03E-07 -1.94E-08 8.41E-11 1.93E-11 -6.32E-14 S6 2.26E+01 2.10E-04 -9.66E-06 -6.35E-07 -2.53E-08 -5.37E-10 1.94E-10 -2.70E-11 S9 -9.98E+01 6.74E-05 2.14E-06 -3.93E-07 -1.07E-08 6.14E-10 -8.43E-12 -6.94E-13 S10 2.62E-01 4.58E-05 -2.31E-06 -2.94E-07 8.44E-09 -6.35E-10 1.52E-11 -2.71E-13 S14 1.23E+01 -4.49E-05 1.46E-05 7.64E-07 -1.07E-07 3.20E-09 9.69E-12 -2.74E-12 S15 1.00E+02 1.16E-03 5.67E-05 -3.25E-06 3.84E-07 -2.59E-09 -1.60E-09 7.23E-11

[0118] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, vertical axis chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are shown as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 shown.

[0119] Figure 2 The field curvature curve of Example 1 is shown, which indicates the degree of curvature of light of different wavelengths on the meridional image plane and the sagittal image plane, the horizontal axis indicates the offset (unit: mm), and the vertical axis indicates the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.03mmmm, indicating that the optical lens can correct the field curvature well.

[0120] Figure 3 The F-Tan (Theta) distortion curve of Example 1 is shown, which represents the distortion of light of different wavelengths at different image heights on the imaging surface, with the horizontal axis representing the distortion value (unit: %) and the vertical axis representing the half field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within -30% to 0, and the image compression in the edge angle area is relatively gentle, which effectively improves the clarity of the expanded image.

[0121] Figure 4 The vertical axis chromatic aberration curve of the optical lens 100 in this embodiment is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging surface, the horizontal axis represents the vertical axis chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 100 can correct the chromatic aberration well.

[0122] Figure 5 The axial aberration curve of the optical lens 100 in this embodiment is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within ±0.01mm, indicating that the optical lens 100 can better correct the axial aberration.

[0123] Figure 6 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.4 in the whole field of view, and in the range of 0 to 180 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency conditions.

[0124] Example 2

[0125] See also Figure 7 , shown is a schematic diagram of the structure of the optical lens provided in Example 2 of the present invention. The optical lens of this embodiment is substantially the same as that of Example 1, and the main difference lies in that the optical parameters such as the curvature radius, aspheric coefficient, thickness, etc. of each lens surface are different.

[0126] The relevant parameters of each lens in the optical lens in Example 2 are shown in Table 2-1.

[0127] Table 2-1

[0128]

[0129] The surface parameters of the aspherical lens of the optical lens in Example 2 are shown in Table 2-2.

[0130] Table 2-2

[0131] Face number K B C D E F G H S5 5.89E+01 3.71E-04 -9.08E-06 -2.42E-07 1.80E-08 -2.92E-09 1.82E-10 -4.35E-12 S6 2.51E+01 4.58E-04 -1.09E-05 -2.41E-07 -2.29E-08 -1.08E-09 1.84E-10 -7.80E-12 S9 -5.60E+01 -1.25E-04 -4.69E-06 -5.98E-07 2.14E-08 -1.10E-09 3.62E-11 -1.03E-12 S10 -1.44E-01 5.03E-05 -2.27E-06 -7.76E-07 2.92E-08 -5.10E-10 -8.89E-12 2.16E-13 S14 4.46E+00 6.58E-05 -1.14E-05 5.53E-07 -5.11E-08 -2.39E-10 2.95E-10 -1.35E-11 S15 -7.82E+01 6.01E-04 2.41E-05 4.22E-07 -6.93E-08 1.59E-08 -1.02E-09 2.77E-11

[0132] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, vertical axis chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are shown as follows: Figure 8 , Fig. 9 , Fig.10 , Fig.11 , Fig.12 shown.

[0133] from Figure 8 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.03mmmm, indicating that the optical lens can correct the field curvature well.

[0134] from Fig. 9 It can be seen that the distortion of the optical lens is controlled within -45% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the expanded image.

[0135] from Fig.10 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens 100 can correct chromatic aberration well.

[0136] from Fig.11 It can be seen that the offset of the axial aberration is controlled within ±0.02 mm, indicating that the optical lens 100 can correct the axial aberration well.

[0137] from Fig.12 It can be seen that the MTF value of this embodiment is above 0.4 in the whole field of view. In the range of 0 to 180 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0138] Example 3

[0139] See also Fig.13 , shown is a schematic diagram of the structure of the optical lens provided in Example 3 of the present invention. The optical lens of this embodiment is substantially the same as that of Example 1, except that: the object side surface S9 of the fifth lens L5 is a convex surface; the object side surface S11 of the sixth lens L6 is a concave surface; and the optical parameters such as the curvature radius, aspheric coefficient, thickness, etc. of each lens surface are different.

[0140] The relevant parameters of each lens in the optical lens in Example 3 are shown in Table 3-1.

[0141] Table 3-1

[0142]

[0143]

[0144] The surface parameters of the aspherical lens of the optical lens in Example 3 are shown in Table 3-2.

[0145] Table 3-2

[0146] Face number K B C D E F G H S5 -8.91E+01 -6.56E-04 2.31E-05 -1.49E-06 8.68E-08 1.41E-10 -1.97E-10 5.27E-12 S6 -3.86E+01 -5.04E-05 -3.54E-06 1.10E-07 3.48E-08 2.47E-10 -1.53E-10 4.30E-12 S9 -6.00E-01 -8.86E-05 2.19E-06 2.23E-07 -5.86E-09 -8.94E-11 1.15E-11 -1.62E-13 S10 6.83E+00 -8.94E-05 1.23E-05 3.67E-07 -3.03E-08 1.26E-09 -1.86E-11 1.46E-13 S14 -6.28E+00 -6.71E-04 -1.59E-05 -3.80E-07 1.59E-08 -3.27E-10 2.51E-11 -5.11E-13 S15 -9.96E+01 -9.74E-04 -8.74E-06 -1.34E-10 6.18E-09 1.87E-10 -1.36E-11 2.17E-13

[0147] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, vertical axis chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are shown as follows: Fig.14 , Fig.15 , Fig.16 , Fig.17 , Fig.18 shown.

[0148] from Fig.14 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.03mmmm, indicating that the optical lens can correct the field curvature well.

[0149] from Fig.15 It can be seen that the distortion of the optical lens is controlled within -30% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the expanded image.

[0150] from Fig.16 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens 100 can correct chromatic aberration well.

[0151] from Fig.17 It can be seen that the offset of the axial aberration is controlled within ±0.01 mm, indicating that the optical lens 100 can correct the axial aberration well.

[0152] from Fig.18 It can be seen that the MTF value of this embodiment is above 0.45 in the whole field of view. In the range of 0 to 180 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0153] Example 4

[0154] See also Fig.19 , shown is a schematic diagram of the structure of the optical lens provided in Example 4 of the present invention. The optical lens of this embodiment is substantially the same as that of Example 1, except that: the object side surface S9 of the fifth lens L5 is a convex surface; the object side surface S11 of the sixth lens L6 is a concave surface; and the optical parameters such as the curvature radius, aspheric coefficient, thickness, etc. of each lens surface are different.

[0155] The relevant parameters of each lens in the optical lens in Example 4 are shown in Table 4-1.

[0156] Table 4-1

[0157]

[0158] The surface parameters of the aspherical lens of the optical lens in Example 4 are shown in Table 4-2.

[0159] Table 4-2

[0160] Face number K B C D E F G H S5 -1.00E+02 -8.16E-04 6.37E-05 -1.09E-06 5.47E-09 -8.06E-10 3.64E-10 -1.75E-11 S6 -9.69E+01 -8.48E-04 5.83E-05 1.90E-06 -1.58E-07 -6.97E-09 1.68E-09 -6.25E-11 S9 -5.03E+00 -3.85E-04 6.20E-06 1.22E-06 -4.69E-08 -6.87E-10 1.81E-10 -4.56E-12 S10 4.13E+00 -3.58E-04 3.44E-05 6.59E-07 -1.82E-08 1.75E-10 5.66E-11 7.83E-13 S14 -4.01E+00 -1.64E-04 1.73E-05 3.53E-06 -1.92E-07 -5.27E-09 1.10E-09 -3.49E-11 S15 1.00E+02 4.79E-04 3.26E-06 5.32E-06 -3.29E-07 4.40E-09 1.06E-09 -3.79E-11

[0161] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, vertical axis chromatic aberration curve, axial aberration curve, and MTF curve of the optical lens are shown as follows: Fig. 20 , Fig.21 , Fig. 22 , Fig.23 , Fig.24 shown.

[0162] from Fig. 20 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.06mmmm, indicating that the optical lens can correct the field curvature well.

[0163] from Fig.21 It can be seen that the distortion of the optical lens is controlled within -30% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the expanded image.

[0164] from Fig. 22 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±1.5 μm, indicating that the optical lens 100 can correct chromatic aberration well.

[0165] from Fig.23 It can be seen from the figure that the offset of the axial aberration is controlled within ±0.01 mm, which means that the optical lens 100 can correct the axial aberration well.

[0166] from Fig.24 It can be seen that the MTF value of this embodiment is above 0.55 in the whole field of view. In the range of 0 to 180 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0167] Please refer to Table 5, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the chief ray incident angle CRA at the maximum image height, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0168] Table 5

[0169]

[0170]

[0171] In summary of the above embodiments, the optical lens provided by the present invention adopts eight lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as ultra-wide angle, high pixel, and high imaging quality.

[0172] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0173] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, comprising eight lenses, characterized in that: 依次包括从物侧到成像面沿光轴的部分: A first lens with a negative optical power, having a convex object side and a concave image side; A second lens with a negative optical power, having a concave object side and a convex image side; A third lens with a negative optical power, having a convex object side and a concave image side; A fourth lens with a positive optical power, having convex object and image sides; A fifth lens with a positive optical power, having a convex image side; A sixth lens with a positive optical power, having a convex image side; A seventh lens with a negative optical power, having concave object and image sides; An eighth lens with a positive optical power, having convex object and image sides; Wherein, the radius of curvature R3 of the object side of the second lens and the radius of curvature R4 of the image side of the second lens satisfy: -7 < (R3 + R4) / (R3 - R4) < -4.

2. The optical lens according to claim 1, characterized in that: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6 < TTL / f < 10.

3. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle satisfy: 1.5 < IH / f < 2.

3.

4. The optical lens according to claim 1, characterized in that: The maximum field of view angle FOV of the optical lens, the effective focal length f of the optical lens, and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 50° < (FOV × f) / IH < 65°.

5. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -25 < f2 / f < -9.

6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the combined focal length f123 of the first lens, the second lens, and the third lens satisfy: -1.6 < f123 / f < -1; the effective focal length f of the optical lens and the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens satisfy: 1.4 < f45678 / f < 2.

2.

7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the radius of curvature R3 of the object side of the second lens satisfy: -2.5 < R3 / f < -1.1; the effective focal length f of the optical lens and the radius of curvature R4 of the image side of the second lens satisfy: -3.8 < R4 / f < -1.

6.

8. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the radius of curvature R5 of the object side of the third lens satisfy: 7.8 < R5 / f < 12.1; the effective focal length f of the optical lens and the radius of curvature R8 of the image side of the fourth lens satisfy: -13.7 < R8 / f < -3.

3.

9. The optical lens according to claim 1, characterized in that: The radius of curvature R9 of the object side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: -5.8 < R9 / R11 < 0; the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 1.2 < |(R9 - R11) / (R9 + R11)| < 1.

7.

10. The optical lens according to claim 1, characterized in that: The sagittal height Sag3 of the clear aperture on the object side of the second lens and the clear aperture diameter d3 of the object side of the second lens satisfy: -0.35 < Sag3 / d3 < -0.15; the sagittal height Sag4 of the clear aperture on the image side of the second lens and the clear aperture diameter d4 of the image side of the second lens satisfy: -0.3 < Sag4 / d4 < -0.1.

Images