Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses in sequence along an optical axis from an object side to an imaging surface, and the eight lenses comprise: a first lens with negative optical power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative optical power, wherein the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; a third lens with positive optical power; a fourth lens with positive optical power; a fifth lens with positive optical power, wherein the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; a sixth lens with negative optical power, wherein the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface; a seventh lens with positive optical power, wherein the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a convex surface; and an eighth lens with positive optical power, wherein the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a convex surface. The optical lens provided by the application has one or more advantages of super wide angle, large imaging surface, large aperture, high imaging quality and the like through specific surface shape matching and reasonable optical power distribution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, and particularly to an optical lens. BACKGROUND

[0002] With the increasing demand for driving experience, vehicle application optical lenses are increasingly used in intelligent driving, and the status of vehicle optical lenses in the automotive industry is continuously improving.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving, which collects environmental information through various lenses combined with sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for ADAS systems, such as light, thin, small shape and high pixel, high resolution, the optical lenses are also required to clearly image under low illumination conditions, so it is necessary to develop an optical lens with good imaging effect. SUMMARY

[0004] To solve the above problems, the present application provides an optical lens with excellent imaging quality.

[0005] The technical scheme adopted by the present application is:

[0006] An optical lens, a total of eight lenses, including in order along the optical axis from the object side to the imaging surface:

[0007] The first lens with negative focal power, the object side surface is convex, and the image side surface is concave;

[0008] The second lens with negative focal power, the object side surface is concave, and the image side surface is concave;

[0009] The third lens with positive focal power;

[0010] The fourth lens with positive focal power;

[0011] The fifth lens with positive focal power, the object side surface is convex, and the image side surface is convex;

[0012] The sixth lens with negative focal power, the object side surface is concave, and the image side surface is concave;

[0013] The seventh lens with positive focal power, the object side surface is convex, and the image side surface is convex;

[0014] The eighth lens with positive focal power, the object side surface is concave, and the image side surface is convex;

[0015] The object side surface curvature radius R15 of the eighth lens and the image side surface curvature radius R16 of the eighth lens satisfy: -0.1 < (R15-R16) / (R15+R16) < 0.7; the object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: -1 < (R13+R14) / (R13-R14) < -0.5.

[0016] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6 < TTL / f < 8; the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.7 < TTL / IH < 3.5.

[0017] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 75° < FOV / Fno < 100°; the real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.2 < IH / EPD < 4.5.

[0018] Further preferably, the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < IH / f < 2.7; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.64 < BFL / f < 1.41.

[0019] Further preferably, the object side surface aperture d1 of the first lens, the real image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.42 < d1 / (IH / 2) / tan(FOV / 2) < 0.71; the combined focal length f123 of the first lens, the second lens and the third 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: -13.4 < f123 / f45678 < -0.8.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3 < f1 / f < -1.7; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1 < f6 / f < -0.5.

[0021] It is further preferred that the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.6 < f2 / f < -1.8; the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy: -0.7 < (R3+R4) / (R3-R4) < 0.2.

[0022] It is further preferred that the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.9 < f5 / f < 1.9; the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy: -0.3 < (R9+R10) / (R9-R10) < 0.3.

[0023] It is further preferred that the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1 < f7 / f < 1.9; the object side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.6 < R13 / f < 1.2; the image side surface curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -13.5 < R14 / f < -4.

[0024] It is further preferred that the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 7 < f8 / f < 40; the object side surface curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -45 < R15 / f < -2.7; the image side surface curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: -19.5 < R16 / f < -2.8.

[0025] The optical lens provided by the application adopts eight lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of super wide angle, large image surface, large aperture, high imaging quality, etc. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0027] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0028] Figure 2 FIG. 2 is an F-Tan(Theta) distortion curve of the optical lens according to the embodiment 1 of the present application.

[0029] Figure 3 FIG. 3 is an MTF curve of the optical lens according to the embodiment 1 of the present application.

[0030] Figure 4 Structure diagram of the optical lens in embodiment 2 of the present application.

[0031] Figure 5 F-Tan(Theta) distortion curve of the optical lens in embodiment 2 of the present application.

[0032] Figure 6 MTF curve diagram of the optical lens in embodiment 2 of the present application.

[0033] Figure 7 Structure diagram of the optical lens in embodiment 3 of the present application.

[0034] Figure 8 F-Tan(Theta) distortion curve of the optical lens in embodiment 3 of the present application.

[0035] Figure 9 MTF curve diagram of the optical lens in embodiment 3 of the present application.

[0036] Figure 10 Structure diagram of the optical lens in embodiment 4 of the present application.

[0037] Figure 11 F-Tan(Theta) distortion curve of the optical lens in embodiment 4 of the present application.

[0038] Figure 12 MTF curve diagram of the optical lens in embodiment 4 of the present application.

[0039] Figure 13 Structure diagram of the optical lens in embodiment 5 of the present application.

[0040] Figure 14 F-Tan(Theta) distortion curve of the optical lens in embodiment 5 of the present application.

[0041] Figure 15 MTF curve diagram of the optical lens in embodiment 5 of the present application.

[0042] Figure 16 Structure diagram of the optical lens in embodiment 6 of the present application.

[0043] Figure 17 F-Tan(Theta) distortion curve of the optical lens in embodiment 6 of the present application.

[0044] Figure 18 MTF curve diagram of the optical lens in embodiment 6 of the present application.

[0045] Figure 19A schematic structural view of an optical lens in Embodiment 7 of the present application.

[0046] Figure 20 An F-Tan(Theta) distortion curve of the optical lens in Embodiment 7 of the present application.

[0047] Figure 21 An MTF curve of the optical lens in Embodiment 7 of the present application.

[0048] Figure 22 A schematic structural view of an optical lens in Embodiment 8 of the present application.

[0049] Figure 23 An F-Tan(Theta) distortion curve of the optical lens in Embodiment 8 of the present application.

[0050] Figure 24 An MTF curve of the optical lens in Embodiment 8 of the present application.

[0051] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0052] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of embodiments of the present application and is not intended to limit the scope of the present application in any way. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0053] It is to be noted that, in the present specification, the expressions first, second, third and the like are used only to distinguish one feature from another feature, and do not denote any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0054] In the drawings, the thickness, size, and shape of lenses have been slightly exaggerated for the sake of explanation. Specifically, the shape of a spherical surface or an aspherical surface shown in the drawings is shown by way of example. That is, the shape of a spherical surface or an aspherical surface is not limited to the shape of a spherical surface or an aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0055] In the present specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0056] It should also be understood that the use of the terms "including", "including having", "having", "containing", and / or "containing having" when used in this specification intends that existence of stated features, elements and / or components but does not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the term "exemplary" is intended to mean an example or an illustration.

[0057] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0058] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. 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 provided by the embodiments of the present application comprises eight lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface as 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.

[0060] In some embodiments, the first lens can have a negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface. The second lens can have a negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface. The third lens can have a positive focal power, the object side surface of which can be a concave surface or a convex surface, and the image side surface of which can be a concave surface or a convex surface. The fourth lens can have a positive focal power, the object side surface of which can be a concave surface or a convex surface, and the image side surface of which can be a concave surface or a convex surface. The fifth lens can have a positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface. The sixth lens can have a negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface. The seventh lens can have a positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface. The eighth lens can have a positive focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface.

[0061] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. When the diaphragm is located between the third lens and the fourth lens, the correction of the diaphragm aberration is facilitated.

[0062] In some embodiments, the optical lens can further include a filter and a protective glass, which are arranged in sequence along the optical axis between the eighth lens and the imaging surface. The filter is used to filter out interference light, preventing the interference light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass protects the optical lens, preventing the photosensitive chip from being damaged and affecting the imaging effect of the lens.

[0063] In some embodiments, the fifth lens, the sixth lens and the seventh lens can be bonded to form a bonded 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; can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0064] In some embodiments, the object side surface radius of curvature R15 of the eighth lens and the image side surface radius of curvature R16 of the eighth lens satisfy: -0.1<(R15-R16) / (R15+R16)<0.7. Satisfying the above range is conducive to suppressing the angle of the edge field of view incident on the imaging surface, effectively transmitting more light beams to the imaging surface, while balancing the field curvature and spherical aberration of the optical lens, and improving the imaging quality of the optical lens. More specifically, -0.02<(R15-R16) / (R15+R16)<0.62.

[0065] In some embodiments, the object side surface radius of curvature R13 of the seventh lens and the image side surface radius of curvature R14 of the seventh lens satisfy: -1<(R13+R14) / (R13-R14)<-0.5. Satisfying the above range can further focus light rays, adjust the angle of the chief ray, optimize the imaging quality, and correct the remaining aberrations (such as distortion, chromatic aberration, etc.), and reduce the distortion of the wide-angle lens. More specifically, -0.88<(R13+R14) / (R13-R14)<-0.67.

[0066] 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<8. Satisfying the above range can effectively limit the length of the lens, which is conducive to realizing the miniaturization of the optical lens. More specifically, 6.31<TTL / f<7.85.

[0067] In some embodiments, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.7<TTL / IH<3.5. Satisfying the above range ensures that the lens has a larger image surface under the condition of the same total length, which can match a larger imaging chip to realize high-definition imaging, and better realize the balance between the small total length and the large image surface of the lens. More specifically, 2.93<TTL / IH<3.32.

[0068] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 75° < FOV / Fno < 100°. Satisfying the above range, the optical lens is defined to have a suitable field of view and aperture value, which can collect light rays of a large angle and obtain good imaging quality. More specifically, 79.9° < FOV / Fno < 94.95°.

[0069] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.2 < IH / EPD < 4.5. Satisfying the above range, the width of the light ray bundle entering the optical lens can be increased, so that the brightness of the optical lens at the image plane is improved to avoid dark corners. More specifically, 3.48 < IH / EPD < 4.13.

[0070] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < IH / f < 2.7. Satisfying the above range, the image height and the focal length of the optical lens are controlled to be within a reasonable range, which helps the optical lens to have a large image surface and improve the imaging quality. More specifically, 2.04 < IH / f < 2.45.

[0071] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.64 < BFL / f < 1.41. Satisfying the above range, the optical lens is defined to have a suitable back focus, which facilitates the reasonable arrangement of the positions of the lenses and reduces the difficulty of processing and assembly.

[0072] In some embodiments, the object side light entrance aperture d1 of the first lens, the real image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.42 < d1 / (IH / 2) / tan(FOV / 2) < 0.71. Satisfying the above range, the optical lens can have a large field of view and a large image surface while the front aperture is small.

[0073] In some embodiments, the combined focal length f123 of the first lens, the second lens and the third 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: -13.4 < f123 / f45678 < -0.8. Satisfying the above range, by reasonably setting the lens group relationship before and after the diaphragm, it is beneficial to balance various aberrations generated by the lens group and improve the overall imaging quality. More specifically, -12.23 < f123 / f45678 < -0.86.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -3 < f1 / f < -1.7. By setting the first lens to have a negative refractive power, the first lens can accommodate light rays of a larger angle and collect as much light as possible into the rear optical system, thereby achieving a large field of view while increasing the light flux. More specifically, -2.79 < f1 / f < -1.85.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1 < f6 / f < -0.5. By satisfying the above range, the light rays at the edge of the field of view have an upward trend, which is beneficial to the image points on the imaging surface being away from the optical axis, thereby achieving the effect of matching a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolving power of the optical lens. More specifically, -0.92 < f6 / f < -0.58.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3.6 < f2 / f < -1.8; the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -0.7 < (R3+R4) / (R3-R4) < 0.2; the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -2.8 < R3 / f < -1.7; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.7 < R4 / f < 9.5. By satisfying the above range, the second lens has a negative focal power and a double-concave surface shape, has the effect of diverging light rays, further diverges the light rays emitted from the image side surface of the first lens at the same field of view angle, can disperse the central light rays and the edge light rays of each field of view, can make the rear optical system have a larger light receiving surface to receive the light emitted from the image side surface of the second lens, thereby achieving a larger light amount and increasing the relative illumination. More specifically, -3.38 < f2 / f < -2.07; -0.63 < (R3+R4) / (R3-R4) < 0.18; -2.62 < R3 / f < -1.83; 1.86 < R4 / f < 8.85.

[0077] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.9 < f5 / f < 1.9; the object-side surface curvature radius R9 of the fifth lens and the image-side surface curvature radius R10 of the fifth lens satisfy: -0.3 < (R9+R10) / (R9-R10) < 0.3; the object-side surface curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.2 < R9 / f < 2.5; and the image-side surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.7 < R10 / f < -0.8. Satisfying the above ranges is conducive to the convergence of light rays, shares the positive refractive power of the third lens and the fourth lens, can avoid excessive deflection of light rays, and better achieves high-quality imaging of the lens. More specifically, 0.98 < f5 / f < 1.75; -0.22 < (R9+R10) / (R9-R10) < 0.27; 1.31 < R9 / f < 2.38; and -2.49 < R10 / f < -0.93.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1 < f7 / f < 1.9; the object-side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.6 < R13 / f < 1.2; and the image-side surface curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -13.5 < R14 / f < -4. Satisfying the above ranges is conducive to the convergence of light rays, smoothly transitions the light ray trend to the rear, reduces the height of light rays incident to the rear, slows the upward trend of light rays, avoids light energy loss caused by excessive angle between the main light ray of the chip and the light rays of the large field of view reaching the imaging surface, is conducive to improving the illumination of the edge field of view, and is conducive to achieving a short total optical length. More specifically, 1.07 < f7 / f < 1.72; 0.64 < R13 / f < 1.12; and -12.47 < R14 / f < -4.2.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 7 < f8 / f < 40; the object-side surface curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -45 < R15 / f < -2.7; and the image-side surface curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: -19.5 < R16 / f < -2.8. Satisfying the above ranges is conducive to the convergence of light rays, smoothly transitions the light ray trend to the rear, reduces the height of light rays incident to the rear, slows the upward trend of light rays, avoids light energy loss caused by excessive angle between the main light ray of the chip and the light rays of the large field of view reaching the imaging surface, is conducive to improving the illumination of the edge field of view, and is conducive to achieving a short total optical length. More specifically, 7.35 < f8 / f < 37.6; -42.49 < R15 / f < -2.97; and -18.05 < R16 / f < -3.03.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 2 < f3 / f < 34. Meeting the above range defines that the third lens has an appropriate positive optical power, has the effect of converging light rays, reduces the height of peripheral light rays, and is beneficial to reducing the aperture of the rear lens. More specifically, 2.15 < f3 / f < 31.84.

[0081] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2 < f4 / f < 9.5. Meeting the above range, the fourth lens has a positive optical power, can further focus light rays, can adjust the angle of the chief ray, optimize the imaging quality, and correct residual aberrations (such as distortion, chromatic aberration, etc.), and reduce the distortion of the wide-angle lens. More specifically, 2.24 < f4 / f < 8.72.

[0082] In some embodiments, the optical lens satisfies the following conditional expressions: 5 mm < f < 7 mm; 3 mm < EPD < 4 mm; 40 mm < TTL < 50 mm; 1.5 < Fno < 1.8; 13° < CRA < 22°; 4 mm < BFL < 9 mm; 130° < FOV < 160°; 13 mm < IH < 14 mm. In the above conditional expressions, f represents the effective focal length 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, CRA represents the chief ray incidence angle of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as ultra-wide angle, large target surface, large aperture, etc. More specifically, 5.58 mm < f < 6.66 mm; 3.2 mm < EPD < 3.92 mm; 40.01 mm < TTL < 45.11 mm; 1.57 < Fno < 1.71; 13.4° < CRA < 22°; 4.32 mm < BFL < 8.49 mm; 135.9° < FOV < 152.3°; 13.61 mm < IH < 13.65 mm.

[0083] 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. On the other hand, when the lens material is glass, due to the low dispersion characteristic of glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. 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.

[0084] 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 a spherical lens or an aspherical lens. Compared with a spherical structure, an aspherical structure can effectively reduce aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better achieving miniaturization of the lens. More specifically, the fourth lens and the eighth lens of the present application adopt an aspherical lens, and the first lens, the second lens, the third lens, the fifth lens, the sixth lens and the seventh lens adopt a spherical lens.

[0085] In various embodiments of the present application, when the lens adopts an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation:

[0086]

[0087] wherein z is the distance of the curved surface from the vertex of the curved surface in the direction of the optical axis, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, and B, C, D, E and F are the fourth-order, sixth-order, eighth-order, tenth-order and twelfth-order surface coefficients, respectively.

[0088] The present application is further described in the following embodiments. In various embodiments, the thickness, the radius of curvature and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement modes, and are included in the protection scope of the present application.

[0089] Embodiment 1

[0090] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the present application. The optical lens 100 includes, in order from the object side to the imaging surface along the optical axis, a first lens L1, a second lens L2, a third lens L3, a diaphragm ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1 and a protective glass G2.

[0091] The first lens L1 has a negative focal power, the object side surface S1 thereof is a convex surface, and the image side surface S2 thereof is a concave surface.

[0092] The second lens L2 has a negative focal power, the object side surface S3 thereof is a concave surface, and the image side surface S4 thereof is a concave surface.

[0093] The third lens L3 has a positive focal power, the object side surface S5 thereof is a convex surface, and the image side surface S6 thereof is a convex surface.

[0094] The fourth lens L4 has positive focal power, the object side S7 is convex, and the image side S8 is convex;

[0095] The fifth lens L5 has positive focal power, the object side S9 is convex, and the image side is convex;

[0096] The sixth lens L6 has negative focal power, the object side is concave, and the image side is concave;

[0097] The seventh lens L7 has positive focal power, the object side is convex, and the image side S12 is convex;

[0098] The fifth lens L5, the sixth lens L6, and the seventh lens L7 form a cemented lens group with positive focal power, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens is S10, and the cemented surface of the image side of the sixth lens L6 and the object side of the seventh lens L7 is S11;

[0099] The eighth lens L8 has positive focal power, the object side S13 is concave, and the image side S14 is convex;

[0100] The object side S15 and the image side S16 of the filter G1 are both flat;

[0101] The object side S17 and the image side S18 of the protective glass G2 are both flat;

[0102] The imaging surface S19 is flat.

[0103] The fourth lens L4 and the eighth lens L8 are glass aspheric lenses; the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses.

[0104] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1.

[0105] Table 1

[0106]

[0107] The surface type parameters of the aspheric lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0108] Table 1-2

[0109] Face number K B C D E F S7 -1.31E+00 1.55E-04 4.09E-08 2.16E-07 -1.03E-08 2.40E-10 S8 -2.81E+00 4.42E-05 -2.53E-07 2.28E-07 -1.16E-08 2.87E-10 S13 2.00E+02 -9.30E-04 -8.52E-06 -5.35E-07 1.57E-08 -5.79E-10 S14 -2.00E+02 -8.32E-04 3.99E-06 -1.68E-07 4.07E-09 -5.15E-11

[0110] Figure 2The F-Tan (Theta) distortion curve of the embodiment 1 is shown, which represents the distortion of light rays of different wavelengths at different image heights on the imaging plane, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion of the optical lens 100 is controlled within-65%~0, the image compression in the edge angle region is relatively gentle, and the clarity of the unfolded image is effectively improved.

[0111] Figure 3 The MTF (Modulation Transfer Function) curve of the embodiment 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.3 in the full field of view, and in the range of 0~120 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0112] Embodiment 2

[0113] Please refer to Figure 4 , which is a structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the present application, and the main difference between the embodiment and the embodiment 1 is that the object side S5 of the third lens L3 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0114] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0115] Table 2-1

[0116]

[0117]

[0118] The surface type parameters of the aspherical lens of the optical lens 200 in the embodiment 2 are shown in Table 2-2.

[0119] Table 2-2

[0120] Face number K B C D E F S7 -5.62E-01 1.04E-04 3.02E-06 2.48E-08 7.79E-11 5.41E-11 S8 6.38E+00 2.37E-04 2.26E-06 2.57E-07 -1.15E-08 3.65E-10 S13 -2.00E+02 -9.05E-04 -1.13E-05 -2.62E-08 -1.22E-08 2.36E-10 S14 6.13E+01 -6.02E-04 -2.09E-06 7.10E-08 -9.44E-10 1.24E-11

[0121] As can be seen from Figure 5 , the distortion of the optical lens 200 is controlled within-70%~0, the image compression in the edge angle region is relatively gentle, and the clarity of the unfolded image is effectively improved.

[0122] As can be seen from Figure 6 , the MTF value of the embodiment is above 0.28 in the full field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0123] Example 3

[0124] Please see Figure 7 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side S6 of the third lens L3 is concave, the object side S7 of the fourth lens L4 is concave, and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0125] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0126] Table 3-1

[0127]

[0128]

[0129] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0130] Table 3-2

[0131] Face number K B C D E F S7 2.00E+02 -3.59E-04 -1.13E-06 -4.11E-08 -4.90E-10 5.10E-11 S8 2.68E+00 -1.19E-04 1.24E-06 -1.63E-07 5.34E-09 -8.15E-11 S13 -1.39E+02 -1.17E-03 -1.75E-05 3.53E-07 -3.42E-08 7.85E-10 S14 1.36E+02 -7.71E-04 -4.30E-06 2.23E-07 -4.43E-09 7.58E-11

[0132] from Figure 8 As can be seen, the distortion of the optical lens 300 is controlled within -60% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.

[0133] from Figure 9 As can be seen, the MTF value of this embodiment is above 0.38 throughout the entire field of view, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0134] Example 4

[0135] Please see Figure 10 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S7 of the fourth lens L4 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0136] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0137] Table 4-1

[0138]

[0139]

[0140] The surface profile parameters of the aspherical lenses of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0141] Table 4-2

[0142] Face number K B C D E F S7 -2.00E+02 -4.05E-04 -8.21E-08 -1.06E-07 4.06E-09 -5.33E-11 S8 7.99E+00 -1.12E-04 1.09E-07 -6.10E-08 3.06E-09 -3.81E-11 S13 1.56E+02 -8.72E-04 -1.58E-05 3.44E-07 -1.71E-08 2.06E-10 S14 1.30E+01 -5.36E-04 -8.73E-06 2.97E-07 -7.69E-09 8.37E-11

[0143] As can be seen from Figure 11 , the distortion of the optical lens 400 is controlled within -70%~0, the image compression in the edge angle region is relatively gentle, and the definition of the unfolded image is effectively improved.

[0144] As can be seen from Figure 12 , the MTF value of the present embodiment is above 0.3 in the full field of view, and has good imaging quality and good detail resolution ability in the low frequency and high frequency cases.

[0145] Embodiment 5

[0146] Referring to Figure 13 , a structure schematic diagram of an optical lens 500 provided in Embodiment 5 of the present application is shown, and the main difference between the present embodiment and Embodiment 1 is that: the image side surface S6 of the third lens L3 is a concave surface; the image side surface S8 of the fourth lens L4 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0147] The related parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0148] Table 5-1

[0149]

[0150]

[0151] The surface profile parameters of the aspherical lenses of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0152] Table 5-2

[0153] Face number K B C D E F S7 1.41E+00 -9.56E-05 5.15E-06 -4.94E-07 2.08E-08 -3.57E-10 S8 1.55E+02 5.30E-04 -4.02E-06 1.42E-06 -6.59E-08 1.75E-09 S13 2.96E+00 -1.15E-03 -2.62E-05 1.57E-06 -1.85E-07 5.10E-09 S14 8.34E+00 -3.92E-04 1.65E-06 1.24E-07 -5.08E-09 1.13E-10

[0154] As can be seen from Figure 14 , the distortion of the optical lens 500 is controlled within -70%~0, the image compression in the edge angle region is relatively gentle, and the definition of the unfolded image is effectively improved.

[0155] As can be seen from Figure 15 , the MTF value of the present embodiment is above 0.25 in the full field of view, and has good imaging quality and good detail resolution ability in the low frequency and high frequency cases.

[0156] Embodiment 6

[0157] Please refer to Figure 16 , which is a structural schematic diagram of the optical lens 600 provided in Embodiment 6 of the present application. Compared with Embodiment 1, the main difference is that the image side S8 of the fourth lens L4 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0158] The related parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0159] Table 6-1

[0160]

[0161]

[0162] The surface type parameters of the aspherical lens of the optical lens 600 in Embodiment 6 are shown in Table 6-2.

[0163] Table 6-2

[0164] Face number K B C D E F S7 1.15E+00 -2.10E-04 1.76E-06 -4.66E-07 1.97E-08 -3.83E-10 S8 1.76E+02 2.97E-04 -1.67E-06 1.02E-06 -4.81E-08 1.60E-09 S13 3.32E+01 -1.27E-03 -4.18E-05 2.51E-06 -2.32E-07 5.43E-09 S14 3.08E+01 -7.61E-04 -6.54E-06 4.58E-07 -1.53E-08 2.27E-10

[0165] It can be seen from Figure 17 that the distortion of the optical lens 600 is controlled within -70%~0, the image compression in the edge angle region is relatively flat, and the clarity of the unfolded image is effectively improved.

[0166] It can be seen from Figure 18 that the MTF value of the present embodiment is above 0.2 in the full field of view, and has good imaging quality and good detail resolution ability in the low frequency and high frequency cases.

[0167] Embodiment 7

[0168] Please refer to Figure 19 , which is a structural schematic diagram of the optical lens 700 provided in Embodiment 7 of the present application. Compared with Embodiment 1, the main difference is that the object side S5 of the third lens L3 is a concave surface; the object side S7 of the fourth lens L4 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0169] The related parameters of each lens in the optical lens 700 in Embodiment 7 are shown in Table 7-1.

[0170] Table 7-1

[0171]

[0172]

[0173] The surface shape parameters of the aspherical lenses of the optical lens 700 in Embodiment 7 are shown in Table 7-2.

[0174] Table 7-2

[0175] Face number K B C D E F S7 -7.61E+01 -2.53E-04 9.26E-08 -4.61E-07 1.81E-08 -3.94E-10 S8 3.83E+00 7.11E-05 1.22E-06 2.06E-08 -2.35E-09 1.36E-10 S13 -5.46E+01 -7.22E-04 -5.66E-06 -4.54E-07 1.63E-08 -4.42E-10 S14 3.80E+01 -5.22E-04 -5.16E-06 1.38E-07 -1.73E-09 1.66E-12

[0176] As can be seen from Figure 20 , the distortion of the optical lens 700 is controlled within -60%~0, the image compression in the edge angle region is relatively gentle, and the definition of the unfolded image is effectively improved.

[0177] As can be seen from Figure 21 , the MTF value of the present embodiment is above 0.35 in the full field of view, and has good imaging quality and good detail resolution ability in the low frequency and high frequency cases.

[0178] Embodiment 8

[0179] Referring to Figure 22 , a structure schematic diagram of an optical lens 800 provided in Embodiment 8 of the present application is shown, and the main difference between the present embodiment and Embodiment 1 is that: the image side surface S6 of the third lens L3 is a concave surface; the image side surface S8 of the fourth lens L4 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0180] The related parameters of each lens in the optical lens 800 in Embodiment 8 are shown in Table 8-1.

[0181] Table 8-1

[0182]

[0183]

[0184] The surface shape parameters of the aspherical lenses of the optical lens 800 in Embodiment 8 are shown in Table 8-2.

[0185] Table 8-2

[0186] Face number K B C D E F S7 1.52E+00 -1.20E-04 -1.08E-06 -1.87E-07 7.99E-09 -2.25E-10 S8 -1.02E+01 3.75E-04 4.37E-06 2.49E-07 -9.28E-09 4.24E-10 S13 2.00E+02 -8.11E-04 -1.99E-05 1.42E-06 -7.48E-08 1.59E-09 S14 1.88E+02 -7.06E-04 -5.04E-06 4.71E-07 -1.53E-08 2.14E-10

[0187] As can be seen from Figure 23 , the distortion of the optical lens 800 is controlled within -70%~0, the image compression in the edge angle region is relatively gentle, and the definition of the unfolded image is effectively improved.

[0188] As can be seen from Figure 24 , the MTF value of the present embodiment is above 0.25 in the full field of view, and has good imaging quality and good detail resolution ability in the low frequency and high frequency cases.

[0189] Please refer to Table 9 for the optical characteristics corresponding to the above-mentioned embodiments, including the effective focal length f, the total track length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV of the optical lens, and the numerical value corresponding to each conditional expression in the embodiments.

[0190] Table 9

[0191]

[0192]

[0193] In summary of the above embodiments, the optical lens provided by the present application adopts eight lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of super wide angle, large image surface, large aperture, high imaging quality, etc.

[0194] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0195] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that, for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, eight pieces of lenses in total, characterized in that, In order from the object side to the imaging plane along the optical axis, successively comprise: a first lens with negative refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a second lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a third lens with positive refractive power; a fourth lens with positive refractive power; a fifth lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a sixth lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a seventh lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; an eighth lens with positive refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; wherein the object side surface curvature radius R15 of the eighth lens and the image side surface curvature radius R16 of the eighth lens satisfy: -0.1<(R15-R16) / (R15+R16)<0.7; the object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: -1<(R13+R14) / (R13-R14)<-0.5; the object side surface aperture d1 of the first lens, the real image height IH corresponding to the maximum field angle of view FOV of the optical lens, and the maximum field angle of view FOV of the optical lens satisfy: 0.42<d1 / (IH / 2) / tan(FOV / 2)<0.71; the combined focal length f123 of the first lens, the second lens and the third 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: -13.4<f123 / f45678<-0.

8.

2. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6<TTL / f<8; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 2.7<TTL / IH<3.

5.

3. The optical lens of claim 1, wherein, The maximum field angle of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 75°<FOV / Fno<100°; the real image height IH corresponding to the maximum field angle of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.2<IH / EPD<4.

5.

4. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field angle of view of the optical lens and the effective focal length f of the optical lens satisfy: 1.8<IH / f<2.7; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.64<BFL / f<1.

41.

5. The optical lens of claim 1, wherein, A radius of curvature R15 of an object side surface of the eighth lens and a radius of curvature R16 of an image side surface of the eighth lens satisfy: -0.02<(R15-R16) / (R15+R16)<0.62; a radius of curvature R13 of an object side surface of the seventh lens and a radius of curvature R14 of an image side surface of the seventh lens satisfy: -0.88<(R13+R14) / (R13-R14)<-0.67; a combined focal length f123 of the first lens, the second lens and the third lens and a combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -12.23<f123 / f45678<-0.

86.

6. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -3<f1 / f<-1.7; the effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: -1<f6 / f<-0.

5.

7. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: -3.6<f2 / f<-1.8; a radius of curvature R3 of an object side surface of the second lens and a radius of curvature R4 of an image side surface of the second lens satisfy: -0.7<(R3+R4) / (R3-R4)<0.

2.

8. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: 0.9<f5 / f<1.9; a radius of curvature R9 of an object side surface of the fifth lens and a radius of curvature R10 of an image side surface of the fifth lens satisfy: -0.3<(R9+R10) / (R9-R10)<0.

3.

9. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f7 of the seventh lens satisfy: 1<f7 / f<1.9; a radius of curvature R13 of an object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.6<R13 / f<1.2; a radius of curvature R14 of an image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -13.5<R14 / f<-4.

10. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f8 of the eighth lens satisfy: 7<f8 / f<40; a radius of curvature R15 of an object side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -45<R15 / f<-2.7; a radius of curvature R16 of an image side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -19.5<R16 / f<-2.8.

Images