Optical lens

Abstract

The application provides an optical lens, which comprises eight lenses with optical power, and sequentially comprises, along an optical axis from an object side to an imaging surface: a first lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; a second lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface; a third lens with negative optical power, whose object side surface is a convex surface at a near optical axis and whose image side surface is a concave surface; a fourth lens with positive optical power; a fifth lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface; a sixth lens with positive optical power, whose image side surface is a convex surface; a seventh lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface; and an eighth lens with positive optical power. The optical lens provided by the application has one or more advantages such as short focal length, large field of view, high imaging quality and the like.

Description

TECHNICAL FIELD

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

[0002] A fisheye lens has the characteristics of super wide-angle shooting, and can accommodate more and wider scenes in the actual shooting picture, and can meet the shooting of some large scene range, and is widely used in the fields of sports cameras, unmanned aerial vehicles, panoramic monitoring and the like. However, the existing fisheye lens device still has many deficiencies, for example, the field angle of the lens is increased, which leads to difficulty in system aberration correction and decline in imaging quality, and the lens size is long and bulky. Therefore, it is necessary to develop an optical lens having one or more advantages of large field angle, high imaging quality, small volume and the like, so as to better meet the market demand. SUMMARY

[0003] In view of the above problems, the present application aims to provide an optical lens having the advantage of excellent imaging quality.

[0004] The technical scheme adopted by the present application is as follows:

[0005] An optical lens, which has a total of eight lenses with optical power, comprises, in order from the object side to the image plane along the optical axis:

[0006] a first lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface;

[0007] a second lens with negative optical power, whose object side surface is a convex surface and whose image side surface is a concave surface;

[0008] a third lens with negative optical power, whose object side surface is a convex surface near the optical axis and whose image side surface is a concave surface;

[0009] a fourth lens with positive optical power;

[0010] a fifth lens with positive optical power, whose object side surface is a convex surface and whose image side surface is a convex surface;

[0011] a sixth lens with positive optical power, whose image side surface is a convex surface;

[0012] a seventh lens with negative optical power, whose object side surface is a concave surface and whose image side surface is a concave surface;

[0013] an eighth lens with positive optical power;

[0014] 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: 0 < (R5-R6) / (R5+R6) < 0.9; and the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: |(R13+R14) / (R13-R14)| < 0.9.

[0015] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 17 < TTL / f < 31; and 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: 6 < TTL / IH < 15.

[0016] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 90° < FOV / Fno < 120°; and 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: 3.5 < IH / EPD < 7.8.

[0017] 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 < 3.5; and the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1.6 < BFL / f < 3.4.

[0018] Further preferably, the total track length TTL of the optical 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: 17 < 180°×TTL / (IH / 2) / (FOV / 2) < 49; and the half light passing radius d1 of the object side surface 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: -6.5 < d1 / (IH / 2) / Tan(FOV / 2) < -2.1.

[0019] Further preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -10 < f2 / f < -3; 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: 6 < R3 / f < 100; and 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: 2 < R4 / f < 5.

[0020] It is further preferred that the focal length f3 of the third lens satisfies -300 < f3 / f < -6.5, the radius of curvature R5 of the object side surface of the third lens satisfies 3.8 < R5 / f < 68, and the radius of curvature R6 of the image side surface of the third lens satisfies 2.3 < R6 / f < 7.5.

[0021] It is further preferred that the focal length f5 of the fifth lens satisfies 3.2 < f5 / f < 10.5, the radius of curvature R9 of the object side surface of the fifth lens satisfies 3.8 < R9 / f < 12, and the radius of curvature R10 of the image side surface of the fifth lens satisfies -10 < R10 / f < -2.9.

[0022] It is further preferred that the focal length f7 of the seventh lens satisfies -2.75 < f7 / f < -1.5, the radius of curvature R13 of the object side surface of the seventh lens satisfies -5 < R13 / f < -1.1, and the radius of curvature R14 of the image side surface of the seventh lens satisfies 3 < R14 / f < 27.

[0023] It is further preferred that the radius of curvature R3 of the object side surface of the second lens satisfies 0.4 < (R3-R4) / (R3+R4) < 1 with respect to the radius of curvature R4 of the image side surface of the second lens, and the radius of curvature R9 of the object side surface of the fifth lens satisfies 0 < (R9+R10) / (R9-R10) < 0.3 with respect to the radius of curvature R10 of the image side surface of the fifth lens.

[0024] 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 such as short focal length, large field of view, high imaging quality, and the like. BRIEF DESCRIPTION OF DRAWINGS

[0025] 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:

[0026] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0027] Figure 2 FIG. 2 is an MTF curve diagram of the optical lens according to the embodiment of the present application.

[0028] Figure 3A structure diagram of an optical lens in Embodiment 2 of the present application.

[0029] Figure 4 An MTF curve diagram of the optical lens in Embodiment 2 of the present application.

[0030] Figure 5 A structure diagram of an optical lens in Embodiment 3 of the present application.

[0031] Figure 6 An MTF curve diagram of the optical lens in Embodiment 3 of the present application.

[0032] Figure 7 A structure diagram of an optical lens in Embodiment 4 of the present application.

[0033] Figure 8 An MTF curve diagram of the optical lens in Embodiment 4 of the present application.

[0034] Figure 9 A structure diagram of an optical lens in Embodiment 5 of the present application.

[0035] Figure 10 An MTF curve diagram of the optical lens in Embodiment 5 of the present application.

[0036] Figure 11 A structure diagram of an optical lens in Embodiment 6 of the present application.

[0037] Figure 12 An MTF curve diagram of the optical lens in Embodiment 6 of the present application.

[0038] Figure 13 A structure diagram of an optical lens in Embodiment 7 of the present application.

[0039] Figure 14 An MTF curve diagram of the optical lens in Embodiment 7 of the present application.

[0040] Figure 15 A structure diagram of an optical lens in Embodiment 8 of the present application.

[0041] Figure 16 An MTF curve diagram of the optical lens in Embodiment 8 of the present application.

[0042] Figure 17 A structure diagram of an optical lens in Embodiment 9 of the present application.

[0043] Figure 18 An MTF curve diagram of the optical lens in Embodiment 9 of the present application.

[0044] Figure 19 A structure diagram of an optical lens in Embodiment 10 of the present application.

[0045] Figure 20 FIG. 11 is a diagram of an MTF curve of an optical lens according to an embodiment of the present application.

[0046] Figure 21 FIG. 12 is a diagram of a structure of an optical lens according to an embodiment of the present application.

[0047] Figure 22 FIG. 13 is a diagram of an MTF curve of an optical lens according to an embodiment of the present application.

[0048] The following detailed description will further describe the present application with reference to the above drawings. DETAILED DESCRIPTION

[0049] For a better understanding of the present application, various aspects of the present application will be described in relation to the drawings. It is to be understood that these detailed descriptions are only descriptions of embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like drawing reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0050] It is to be noted that the expressions first, second, third, etc. in the present specification are used only to distinguish one feature from another feature, and do not indicate 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.

[0051] 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.

[0052] 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.

[0053] It should also be understood that the use of the terms "have", "has", "having", "include", "includes", "including", "comprise", "comprises" and / or "comprising", when appearing in the specification, is taken as

[0054] 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 overly literal or overly formal sense unless expressly so defined herein.

[0055] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other, without conflict, and the embodiments in the present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0056] The optical lens provided by the embodiments of the present application comprises eight lenses with optical power, 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.

[0057] In some embodiments, the first lens can have negative optical power, the object side surface thereof can be convex, and the image side surface thereof can be concave. The second lens can have negative optical power, the object side surface thereof can be convex, and the image side surface thereof can be concave. The third lens can have negative optical power, the object side surface thereof can be convex at the near optical axis, and the image side surface thereof can be concave. The fourth lens can have positive optical power, the object side surface thereof can be convex or concave, and the image side surface thereof can be convex or concave. The fifth lens can have positive optical power, the object side surface thereof can be convex, and the image side surface thereof can be convex. The sixth lens can have positive optical power, the object side surface thereof can be convex or concave, and the image side surface thereof can be convex. The seventh lens can have negative optical power, the object side surface thereof can be concave, and the image side surface thereof can be concave. The eighth lens can have positive optical power, the object side surface thereof can be convex or concave, and the image side surface thereof can be convex or concave.

[0058] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the fourth lens and the fifth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging.

[0059] In some embodiments, the optical lens can further include a filter disposed along the optical axis 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.

[0060] In some embodiments, the sixth lens and the seventh lens can be cemented together to form a cemented lens, which can effectively correct chromatic aberration of the optical lens, reduce sensitivity of the optical lens to decentration, balance aberration of the optical lens, and improve imaging quality of the optical lens; and can also reduce 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.

[0061] 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: 0 < (R5-R6) / (R5+R6) < 0.9; and the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: |(R13+R14) / (R13-R14)| < 0.9. Satisfying the above ranges is conducive to adjusting the light path, so that the optical lens has a large field of view angle characteristic. More specifically, 0.06 < (R5-R6) / (R5+R6) < 0.9; -0.9 < (R13+R14) / (R13-R14) < 0.1.

[0062] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 17 < TTL / f < 31; and the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 6 < TTL / IH < 15. Satisfying the above ranges can effectively limit the length of the lens, which is conducive to miniaturization of the optical lens. More specifically, 18.58 < TTL / f < 29.9; 6.14 < TTL / IH < 13.73.

[0063] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 90° < FOV / Fno < 120°; and the real 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: 3.5 < IH / EPD < 7.8. Satisfying the above ranges reasonably limits the ratio of the field of view angle to the aperture value, which is conducive to improving the amount of light entering the lens, so that the lens can also have high-definition imaging in a dim environment. At the same time, reasonably limiting the ratio of the image height to the entrance pupil diameter is conducive to increasing the amount of light, so that the brightness of the peripheral field of view and the central field of view is more uniform. More specifically, 95.64° < FOV / Fno < 110.1°; 3.84 < IH / EPD < 7.11.

[0064] In some embodiments, a real image height IH corresponding to a maximum field of view angle of the optical lens and an effective focal length f of the optical lens satisfy: 1.8<IH / f<3.5; a back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1.6<BFL / f<3.4. Satisfying the above ranges can achieve a larger field of view angle and ensure a large depth of field. At the same time, the optical lens is limited to have a suitable back focus, which facilitates reasonable arrangement of positions of the lenses and reduces the difficulty of processing and assembly. More specifically: 1.92<IH / f<3.24; 1.7<BFL / f<3.16.

[0065] In some embodiments, an optical total length TTL of the optical lens, a real image height IH corresponding to a maximum field of view angle of the optical lens, and a maximum field of view angle FOV of the optical lens satisfy: 17<180°×TTL / (IH / 2) / (FOV / 2)<49; a half light passing radius d1 of an object side surface of the first lens, the real 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: -6.5<d1 / (IH / 2) / Tan(FOV / 2)<-2.1. Satisfying the above ranges is conducive to balancing the relationship among the total length, the image height, and the field of view angle of the optical lens. At the same time, the overall geometric shape of the optical lens can be reasonably arranged, and the structural stability thereof can be improved. More specifically: 18.43<180°×TTL / (IH / 2) / (FOV / 2)<44.92; -6.01<d1 / (IH / 2) / Tan(FOV / 2)<-2.36.

[0066] In some embodiments, a focal length f2 of the second lens and an effective focal length f of the optical lens satisfy: -10<f2 / f<-3; a radius of curvature R3 of an object side surface of the second lens and the effective focal length f of the optical lens satisfy: 6<R3 / f<100; a radius of curvature R4 of an image side surface of the second lens and the effective focal length f of the optical lens satisfy: 2<R4 / f<5. Satisfying the above ranges reasonably limits the refractive power ratio and the surface shape of the second lens, which can further diverge light rays and improve the field of view angle of the imaging system. More specifically: -9.24<f2 / f<-3.34; 6.37<R3 / f<91.38; 2.25<R4 / f<4.71.

[0067] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -300 < f3 / f < -6.5; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 3.8 < R5 / f < 68; and the radius of curvature R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R6 / f < 7.5. Satisfying the above ranges, the proportion of refractive power and the surface shape of the third lens are reasonably limited, which is conducive to adjusting the light distribution from the first lens and the second lens, making the marginal rays continue to diverge after passing through the third lens, and correcting the marginal field aberration. More specifically, -292.43 < f3 / f < -7; 4.16 < R5 / f < 62.36; and 2.56 < R6 / f < 7.01.

[0068] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 3.2 < f5 / f < 10.5; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 3.8 < R9 / f < 12; and the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -10 < R10 / f < -2.9. Satisfying the above ranges, the proportion of refractive power and the surface shape of the fifth lens are reasonably limited, which, in cooperation with the fourth lens, further limits the light distribution and balances the aberration. More specifically, 3.47 < f5 / f < 9.83; 4.14 < R9 / f < 11.35; and -9.78 < R10 / f < -3.17.

[0069] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -2.75 < f7 / f < -1.5; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -5 < R13 / f < -1.1; and the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 3 < R14 / f < 27. Satisfying the above ranges, the proportion of refractive power and the surface shape of the seventh lens are reasonably limited, which can effectively correct the aberration generated at the front end of the lens and improve the imaging quality of the lens. More specifically, -2.51 < f7 / f < -1.63; -4.69 < R13 / f < -1.21; and 3.26 < R14 / f < 24.9.

[0070] In some embodiments, 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: 0.4 < (R3-R4) / (R3+R4) < 1; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: 0 < (R9+R10) / (R9-R10) < 0.3. Satisfying the above range, the aberration of the optical lens can be corrected, and the tolerance sensitivity of the optical lens is reduced. More specifically: 0.42 < (R3-R4) / (R3+R4) < 0.95; 0.05 < (R9+R10) / (R9-R10) < 0.3.

[0071] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -70 < f1 / f < -6.2. Satisfying the above range, the proportion of the refractive power of the first lens is reasonably limited, the light rays at a large field of view can be collected to a greater extent, the light rays enter the rear optical system, the light flux is increased, and the field of view angle is improved. More specifically: -68.54 < f1 / f < -6.84.

[0072] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 5.2 < f4 / f < 14.5. Satisfying the above range, the proportion of the refractive power of the fourth lens is reasonably limited, the light rays can be converged, and the aberration problem caused by the first three negative focal length lenses is corrected. More specifically: 5.69 < f4 / f < 13.24.

[0073] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1.6 < f6 / f < 4.2. Satisfying the above range, the proportion of the refractive power of the sixth lens is reasonably limited, the aberration of the edge field of view can be effectively improved, and the overall imaging quality of the optical lens is improved. More specifically: 1.78 < f6 / f < 3.89.

[0074] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: 3.6 < f8 / f < 70. Satisfying the above range, the proportion of the refractive power of the eighth lens is reasonably limited, which is beneficial to reduce the eccentricity sensitivity of the optical lens and improve the imaging resolution. More specifically: 3.9 < f8 / f < 64.87.

[0075] In some embodiments, the combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 2.7 < f5678 / f < 4.2. Satisfying the above range, the proportion of the refractive power of the diaphragm rear lens group is limited, which is beneficial to correct the chromatic aberration and field curvature of the optical system, reduce the sensitivity, and reduce the difficulty of lens forming. More specifically: 2.98 < f5678 / f < 3.97.

[0076] In some embodiments, the optical lens satisfies the following conditional expressions: 0.5mm < f < 0.85mm; 210° < FOV < 250°; 0.2mm < EPD < 0.4mm; 12mm < TTL < 18mm; 1.9 < Fno < 2.4; 1.1mm < IH < 2.8mm; 10° < CRA < 30°; 1.1mm < BFL < 2.5mm. In the above conditional expressions, 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 real image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Satisfying the above ranges, the optical lens has one or more advantages such as short focal length, large field of view angle, high imaging quality, etc. More specifically, 0.54mm < f < 0.82mm; 219° < FOV < 241°; 0.24mm < EPD < 0.38mm; 12.7mm < TTL < 17.89mm; 1.99 < Fno < 2.31; 1.18mm < IH < 2.59mm; 10.26° < CRA < 29.1°; 1.14mm < BFL < 2.41mm.

[0077] In some embodiments, the lens material in the optical lens provided by the present application 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. In the optical lens provided by the present application, the first lens, the second lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens can be made of glass, and the third lens and the fifth lens can be made of plastic. The use of the glass-plastic hybrid structure can effectively reduce the cost, correct the aberration, reduce the size, improve the thermal stability, and provide an optical lens product with higher performance-price ratio.

[0078] 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 be a spherical lens or an aspherical lens. 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 achieving the miniaturization of the lens. More specifically, the first lens, the second lens, the fourth lens, the sixth lens, the seventh lens, and the eighth lens of the present application are spherical lenses, and the third lens and the fifth lens are aspherical lenses.

[0079] In various embodiments of the present application, when the lens is an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation:

[0080] ;

[0081] wherein z is the distance of the curved surface to the vertex of the curved surface in the direction of the optical axis, h is the distance of the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the coefficient of the quadratic curved surface, and B, C, D, E, F, G, and H are the coefficients of the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order curved surfaces, respectively.

[0082] The application will be further described in the following embodiments. In each embodiment, 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 merely the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, and any change, substitution, combination, or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement, and should be included in the protection scope of the application.

[0083] Embodiment 1

[0084] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the application. The optical lens 100 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, a fourth lens L4, a stop ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a filter G1.

[0085] 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.

[0086] The second lens L2 has a negative focal power, the object side surface S3 thereof is a convex surface, and the image side surface S4 thereof is a concave surface.

[0087] The third lens L3 has a negative focal power, the object side surface S5 thereof is a convex surface at the near optical axis, and the image side surface S6 thereof is a concave surface.

[0088] The fourth lens L4 has a positive focal power, the object side surface S7 thereof is a convex surface, and the image side surface S8 thereof is a convex surface.

[0089] The fifth lens L5 has a positive focal power, the object side surface S9 thereof is a convex surface, and the image side surface S10 thereof is a convex surface.

[0090] The sixth lens L6 has a positive focal power, the object side surface S11 thereof is a convex surface, and the image side surface thereof is a convex surface.

[0091] The seventh lens L7 has a negative focal power, the object side surface S12 thereof is a concave surface, and the image side surface S13 thereof is a concave surface.

[0092] The sixth lens L6 and the seventh lens L7 form a cemented lens group, that is, the cemented surface of the image side surface of the sixth lens L6 and the object side surface of the seventh lens L7 is S12;

[0093] The eighth lens L8 has positive refractive power, the object side surface S14 is a convex surface, and the image side surface S15 is a convex surface;

[0094] The object side surface S16 and the image side surface S17 of the filter G1 are both flat surfaces;

[0095] The imaging surface S18 is a flat surface.

[0096] The first lens L1, the second lens L2, the fourth lens L4, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are all glass spherical lenses, and the third lens L3 and the fifth lens L5 are plastic aspherical lenses.

[0097] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0098] Table 1-1

[0099]

[0100] The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0101] Table 1-2

[0102]

[0103] In this embodiment, the MTF curve of the optical lens 100 is shown in Figure 2 .

[0104] Figure 2 The MTF (Modulation Transfer Function) curve of Embodiment 1 is shown, which represents the lens imaging modulation degree of 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. As can be seen from the figure, the MTF value of this embodiment is above 0.4 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0105] Embodiment 2

[0106] Please refer to Figure 3 , which is a structure schematic diagram of the optical lens 200 provided in Embodiment 2 of the application, compared with Embodiment 1, the main difference is that the image side surface S15 of the eighth lens L8 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0107] The related parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0108] Table 2-1

[0109]

[0110] The surface type parameters of the aspheric lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0111] Table 2-2

[0112]

[0113] In this embodiment, the MTF curve of the optical lens 200 is shown in Figure 4 From Figure 4 it can be seen that the MTF value of this embodiment is above 0.5 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0114] Embodiment 3

[0115] Please refer to Figure 5 , which is a structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present application. Compared with Embodiment 1, the main difference is that the object side S11 of the sixth lens L6 is a concave surface; the image side S15 of the eighth lens L8 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0116] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0117] Table 3-1

[0118]

[0119] The surface type parameters of the aspheric lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0120] Table 3-2

[0121]

[0122] In this embodiment, the MTF curve of the optical lens 300 is shown in Figure 6 From Figure 6As can be seen from the MTF curves in FIG. 6, the MTF values of the optical lens 400 in this embodiment are all above 0.4 in the full field of view, and in the range of 0-160 lp / mm, the MTF curves uniformly and smoothly decrease from the center to the edge of the field of view, and the imaging quality and the detail resolution capability are good in both low and high frequency cases.

[0123] Embodiment 4

[0124] Referring to FIG. 4, a structural schematic diagram of an optical lens 400 provided in Embodiment 4 of the present application is shown. Compared with Embodiment 1, the main difference is that: the object side S7 of the fourth lens L4 is a concave surface; the image side S15 of the eighth lens L8 is a concave surface; and the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different. Figure 7

[0125] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0126] Table 4-1

[0127]

[0128] The surface type parameters of the aspheric lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0129] Table 4-2

[0130]

[0131] In this embodiment, the MTF curve diagram of the optical lens 400 is shown in FIG. 6. As can be seen from the MTF curves in FIG. 6, the MTF values of the optical lens 400 in this embodiment are all above 0.4 in the full field of view, and in the range of 0-160 lp / mm, the MTF curves uniformly and smoothly decrease from the center to the edge of the field of view, and the imaging quality and the detail resolution capability are good in both low and high frequency cases. Figure 8 Figure 8 Embodiment 5

[0132] Referring to FIG. 5, a structural schematic diagram of an optical lens 500 provided in Embodiment 5 of the present application is shown. Compared with Embodiment 1, the main difference is that: the image side S8 of the fourth lens L4 is a concave surface; the image side S15 of the eighth lens L8 is a concave surface; and the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0133] The related parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1. Figure 9 Table 5-1

[0134]

[0135]

[0136] ​​​​

[0137] The surface profile parameters of the aspherical lenses of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0138] Table 5-2

[0139]

[0140] In this embodiment, the MTF curve of the optical lens 500 is shown in Figure 10 It can be seen from Figure 10 that the MTF value of this embodiment is above 0.5 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low and high frequency cases.

[0141] Embodiment 6

[0142] Please refer to Figure 11 , 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 object side S14 of the eighth lens L8 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0143] The related parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0144] Table 6-1

[0145]

[0146] The surface profile parameters of the aspherical lenses of the optical lens 600 in Embodiment 6 are shown in Table 6-2.

[0147] Table 6-2

[0148]

[0149] In this embodiment, the MTF curve of the optical lens 600 is shown in Figure 12 It can be seen from Figure 12 that the MTF value of this embodiment is above 0.5 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low and high frequency cases.

[0150] Embodiment 7

[0151] Please refer to Figure 13, as shown in Fig. 7 is a structural schematic diagram of the optical lens 700 provided in the embodiment 7 of the present application. Compared with the embodiment 1, the main difference is that the image side surface 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.

[0152] The related parameters of each lens in the optical lens 700 in the embodiment 7 are shown in Table 7-1.

[0153] Table 7-1

[0154]

[0155] The surface type parameters of the aspheric lens of the optical lens 700 in the embodiment 7 are shown in Table 7-2.

[0156] Table 7-2

[0157]

[0158] In the embodiment, the MTF curve diagram of the optical lens 700 is shown in Figure 14 . It can be seen from Figure 14 that the MTF value of the embodiment is above 0.6 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0159] Embodiment 8

[0160] Please refer to Figure 15 , as shown in Fig. 8 is a structural schematic diagram of the optical lens 800 provided in the embodiment 8 of the present application. Compared with the embodiment 1, the main difference is that the object side surface S7 of the fourth lens L4 is a concave surface; the object side surface S11 of the sixth lens L6 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0161] The related parameters of each lens in the optical lens 800 in the embodiment 8 are shown in Table 8-1.

[0162] Table 8-1

[0163]

[0164] The surface type parameters of the aspheric lens of the optical lens 800 in the embodiment 8 are shown in Table 8-2.

[0165] Table 8-2

[0166]

[0167] In the embodiment, the MTF curve diagram of the optical lens 800 is shown inFigure 16 As shown in Figure 16 It can be seen from

[0168] Embodiment 9

[0169] As shown in Figure 17 , which is a structural schematic diagram of the optical lens 900 provided in the embodiment 9 of the present application. Compared with the embodiment 1, the main difference of the present embodiment is that the object side S11 of the sixth lens L6 is a concave surface; the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0170] The related parameters of each lens in the optical lens 900 in the embodiment 9 are shown in Table 9-1.

[0171] Table 9-1

[0172]

[0173] The surface type parameters of the aspheric lens of the optical lens 900 in the embodiment 9 are shown in Table 9-2.

[0174] Table 9-2

[0175]

[0176] In the present embodiment, the MTF curve diagram of the optical lens 900 is as shown in Figure 18 It can be seen from Figure 18 that the MTF value of the present embodiment is above 0.5 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0177] Embodiment 10

[0178] As shown in Figure 19 , which is a structural schematic diagram of the optical lens 1000 provided in the embodiment 10 of the present application. Compared with the embodiment 1, the main difference of the present embodiment is that the image side S8 of the fourth lens L4 is a concave surface; the object side S11 of the sixth lens L6 is a concave surface; the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0179] The related parameters of each lens in the optical lens 1000 in the embodiment 10 are shown in Table 10-1.

[0180] Table 10-1

[0181]

[0182] The surface profile parameters of the aspherical lenses of the optical lens 1000 in Embodiment 10 are shown in Table 10-2.

[0183] Table 10-2

[0184]

[0185] In this embodiment, the MTF curve of the optical lens 1000 is shown in Figure 20 From Figure 20 it can be seen that the MTF value of this embodiment is above 0.5 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low and high frequency cases.

[0186] Embodiment 11

[0187] Please refer to Figure 21 , which is a structural schematic diagram of the optical lens 1100 provided in Embodiment 11 of the present application. Compared with Embodiment 1, the main difference is that: the image side surface S8 of the fourth lens L4 is a concave surface; the object side surface S11 of the sixth lens L6 is a concave surface; the image side surface S15 of the eighth lens L8 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0188] The related parameters of each lens in the optical lens 1100 in Embodiment 11 are shown in Table 11-1.

[0189] Table 11-1

[0190]

[0191] The surface profile parameters of the aspherical lenses of the optical lens 1100 in Embodiment 11 are shown in Table 11-2.

[0192] Table 11-2

[0193]

[0194] In this embodiment, the MTF curve of the optical lens 1100 is shown in Figure 22 From Figure 22 it can be seen that the MTF value of this embodiment is above 0.4 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low and high frequency cases.

[0195] Please refer to Table 12-1, Table 12-2, Table 12-3 and Table 12-4 for the optical characteristics of the above-mentioned embodiments, including the effective focal length f, the total track length TTL, the aperture value Fno, the chief ray angle of incidence CRA at the maximum image height, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, the entrance pupil diameter EPD, the back focal length BFL, and the numerical values corresponding to each conditional expression in the embodiments.

[0196] Table 12-1

[0197]

[0198] Table 12-2

[0199]

[0200] Table 12-3

[0201]

[0202] Table 12-4

[0203]

[0204] 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 such as short focal length, large field of view angle, and high imaging quality.

[0205] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" 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.

[0206] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot 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, several modifications and improvements can be made without departing from the concept of the present application, 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 comprising eight lenses with optical power, characterized in that, 依次包括从物侧到成像面沿光轴的部分: A first lens with negative optical power, having a convex object side and a concave image side; A second lens with negative optical power, having a convex object side and a concave image side; A third lens with negative optical power, having a convex object side near the optical axis and a concave image side; A fourth lens with positive optical power; A fifth lens with positive optical power, having a convex object side and a convex image side; A sixth lens with positive optical power, having a convex image side; A seventh lens with negative optical power, having a concave object side and a concave image side; An eighth lens with positive optical power; Wherein, the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: 0 < (R5 - R6) / (R5 + R6) < 0.9; the curvature radius R13 of the object side of the seventh lens and the curvature radius R14 of the image side of the seventh lens satisfy: |(R13 + R14) / (R13 - R14)| < 0.9; The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 17 < TTL / f < 31; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 6 < TTL / IH < 15.

2. The optical lens according to claim 1, characterized in that, The curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: 0.06 < (R5 - R6) / (R5 + R6) < 0.9; the curvature radius R13 of the object side of the seventh lens and the curvature radius R14 of the image side of the seventh lens satisfy: -0.9 < (R13 + R14) / (R13 - R14) < 0.1; The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 18.58 < TTL / f < 29.9; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 6.14 < TTL / IH < 13.

73.

3. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 90° < FOV / Fno < 120°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.5 < IH / EPD < 7.

8.

4. The optical lens according to claim 1, characterized in that, The true 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 < 3.5; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1.6 < BFL / f < 3.

4.

5. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 17 < 180°×TTL / (IH / 2) / (FOV / 2) < 49; the clear aperture semi-diameter d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: -6.5 < d1 / (IH / 2) / Tan(FOV / 2) < -2.

1.

6. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -10 < f2 / f < -3; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 6 < R3 / f < 100; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 2 < R4 / f < 5.

7. The optical lens according to claim 1, characterized in that, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -300 < f3 / f < -6.5; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 3.8 < R5 / f < 68; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R6 / f < 7.

5.

8. The optical lens according to claim 1, characterized in that, The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 3.2 < f5 / f < 10.5; the curvature radius R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 3.8 < R9 / f < 12; the curvature radius R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -10 < R10 / f < -2.

9.

9. The optical lens according to claim 1, characterized in that, The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -2.75 < f7 / f < -1.5; the curvature radius R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -5 < R13 / f < -1.1; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 3 < R14 / f < 27.

10. The optical lens according to claim 1, characterized in that, The curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: 0.4 < (R3 - R4) / (R3 + R4) < 1; the curvature radius R9 of the object side surface of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: 0 < (R9 + R10) / (R9 - R10) < 0.3.

Images