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, wherein an object side surface of the first lens is a concave surface and an image side surface of the first lens is a convex surface; a second lens with positive optical power, wherein an object side surface of the second lens is a convex surface; a third lens with negative optical power, wherein an object side surface of the third lens is a concave surface and an image side surface of the third lens is a concave surface; a fourth lens with positive optical power, wherein an object side surface of the fourth lens is a convex surface and an image side surface of the fourth lens is a convex surface; a fifth lens with positive optical power, wherein an object side surface of the fifth lens is a convex surface and an image side surface of the fifth lens is a convex surface; a sixth lens with negative optical power, wherein an object side surface of the sixth lens is a concave surface and an image side surface of the sixth lens is a concave surface; a seventh lens with negative optical power, wherein an object side surface of the seventh lens is a concave surface and an image side surface of the seventh lens is a concave surface; and an eighth lens with negative optical power. The optical lens provided by the application has one or more advantages such as long focal length, large aperture, high imaging quality and the like.

Description

TECHNICAL FIELD

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

[0002] At present, with the vigorous development of automobile auxiliary driving and automatic driving technology, vehicle-mounted cameras play a crucial role. Vehicle-mounted cameras are of various types, including interior, rear, front, side and all-around view cameras. Each type has unique functions and different application scenarios. For example, front wide-angle cameras are mainly used for accurately identifying close-range objects, and can provide key information for driving in urban road conditions and low-speed driving scenarios.

[0003] Front cameras are the core components of ADAS (Advanced Driver Assistance System). They not only undertake the task of distance measurement, but also accurately identify objects and clearly distinguish road markings. Therefore, the visual algorithms required for front cameras are extremely complex and have high technical thresholds. In order to fully utilize the performance of front cameras, it is urgent to develop an optical lens with excellent imaging effect. Only in this way can the front camera work stably and efficiently in complex driving environments and lay a solid foundation for the further development of automatic driving technology. SUMMARY

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

[0005] The technical solution adopted by the present application is as follows:

[0006] An optical lens, which comprises eight lenses with optical power, arranged in order along the optical axis from the object side to the imaging surface, comprising:

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

[0008] a second lens with positive optical power, whose object side surface is convex;

[0009] a third lens with negative optical power, whose object side surface is concave and whose image side surface is concave;

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

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

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

[0013] a seventh lens with negative optical power, whose object side surface is concave and whose image side surface is concave;

[0014] the eighth lens has a negative focal length;

[0015] wherein a combined focal length f12 of the first lens and the second lens and an effective focal length f of the optical lens satisfy: 0.75 < f12 / f < 1.8.

[0016] Further preferably, an optical total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.5 < TTL / f < 1.9; the optical total track length TTL of the optical lens and a real image height IH corresponding to a maximum field of view angle of the optical lens satisfy: 2.3 < TTL / IH < 3.4.

[0017] Further preferably, a real image height IH corresponding to a maximum field of view angle of the optical lens and an entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.1; the real image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 < IH / f < 0.7.

[0018] Further preferably, a half light entrance radius d1 of an object side surface of the first lens, a real image height IH corresponding to a maximum field of view angle of the optical lens and the maximum field of view angle FOV of the optical lens satisfy: 3.5 < d1 / (IH / 2) / Tan(FOV / 2) < 4.5; a combined focal length f12 of the first lens and the second lens and a combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens satisfy: 0.8 < f12 / f1234 < 1.8.

[0019] Further preferably, a focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2 < f1 / f < -1.35; a radius of curvature R1 of an object side surface of the first lens and the effective focal length f of the optical lens satisfy: -0.45 < R1 / f < -0.25; a radius of curvature R2 of an image side surface of the first lens and the effective focal length f of the optical lens satisfy: -0.7 < R2 / f < -0.4.

[0020] Further preferably, a focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < f2 / f < 1; a focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < f4 / f < 0.7.

[0021] It is further preferred that the focal length f3 of the third lens satisfies -0.7 < f3 / f < -0.4, the radius of curvature R5 of the object side surface of the third lens satisfies -4.8 < R5 / f < -2.7, and the radius of curvature R6 of the image side surface of the third lens satisfies 0.35 < R6 / f < 0.55.

[0022] It is further preferred that the focal length f7 of the seventh lens satisfies -2.7 < f7 / f < -1, the radius of curvature R13 of the object side surface of the seventh lens satisfies -5.9 < R13 / f < -2.2, and the radius of curvature R14 of the image side surface of the seventh lens satisfies 0.9 < R14 / f < 5.4.

[0023] It is further preferred that the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens satisfies -0.85 < f1234 / f5678 < -0.25, and the combined focal length f34 of the third lens and the fourth lens satisfies 0 < f34 / f56 < 9.5.

[0024] It is further preferred that the radius of curvature R5 of the object side surface of the third lens satisfies 1.15 < (R5-R6) / (R5+R6) < 1.45, or the radius of curvature R1 of the object side surface of the first lens satisfies -5.4 < (R1+R2) / (R1-R2) < -3.6, or the radius of curvature R7 of the object side surface of the fourth lens satisfies -0.55 < (R7+R8) / (R7-R8) < -0.1, or the radius of curvature R13 of the object side surface of the seventh lens satisfies |(R13+R14) / (R13-R14)| < 0.7.

[0025] 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 long focal length, 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 Structure diagram of the optical lens in Embodiment 1 of the present application.

[0028] Figure 2 MTF curve diagram of the optical lens in Embodiment 1 of the present application.

[0029] Figure 3 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0030] Figure 4 MTF curve diagram of the optical lens in Embodiment 2 of the present application.

[0031] Figure 5 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0032] Figure 6 MTF curve diagram of the optical lens in Embodiment 3 of the present application.

[0033] Figure 7 Structure diagram of the optical lens in Embodiment 4 of the present application.

[0034] Figure 8 MTF curve diagram of the optical lens in Embodiment 4 of the present application.

[0035] Figure 9 Structure diagram of the optical lens in Embodiment 5 of the present application.

[0036] Figure 10 MTF curve diagram of the optical lens in Embodiment 5 of the present application.

[0037] Figure 11 Structure diagram of the optical lens in Embodiment 6 of the present application.

[0038] Figure 12 MTF curve diagram of the optical lens in Embodiment 6 of the present application.

[0039] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0040] For a better understanding of the present application, various aspects of the present application will be described in more detail below 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 description, 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.

[0041] It should be noted that the terms first, second, third, etc. in the present description are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, 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.

[0042] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0043] In this context, the paraxial region refers to a region near the optical axis. If the 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 the 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 imaging surface is referred to as the image side surface of the lens.

[0044] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, mean that there are the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when expressions such as "at least one of" appear after a list of features, the expression is to be construed to mean that the features in the list are present individually, and not that the features are present collectively. Furthermore, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0045] Unless otherwise defined, all terms used in this document, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms (for example, terms 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.

[0046] 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 drawings and in conjunction with embodiments.

[0047] The optical lens provided by the embodiment 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.

[0048] In some embodiments, the first lens can have negative optical power, the object side surface thereof can be a concave surface, and the image side surface thereof can be a convex surface. The second lens can have positive optical power, the object side surface thereof can be a convex surface, and the image side surface thereof can be a convex surface or a concave surface. The third lens can have negative optical power, the object side surface thereof can be a concave surface, and the image side surface thereof can be a concave surface. The fourth lens can have positive optical power, the object side surface thereof can be a convex surface, and the image side surface thereof can be a convex surface. The fifth lens can have positive optical power, the object side surface thereof can be a convex surface, and the image side surface thereof can be a convex surface. The sixth lens can have negative optical power, the object side surface thereof can be a concave surface, and the image side surface thereof can be a concave surface. The seventh lens can have negative optical power, the object side surface thereof can be a concave surface, and the image side surface thereof can be a concave surface. The eighth lens can have negative optical power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof can be a convex surface or a concave surface.

[0049] In some embodiments, the optical lens can further comprise a diaphragm, which can be arranged between the first lens and the second lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging.

[0050] In some embodiments, the optical lens can further comprise a filter and a protective glass, which are sequentially arranged along the optical axis between the eighth lens and the imaging surface. The filter is used to filter out the interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting the normal imaging. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the impact resistance and scratch resistance of the optical lens, while having little effect on the imaging quality of the optical lens.

[0051] In some embodiments, the third lens and the fourth lens can be bonded to form a bonded lens, and the fifth lens and the sixth lens can be bonded to form a bonded lens, which can effectively correct the chromatic aberration of the optical lens, reduce the sensitivity of the optical lens to decentration, balance the aberration of the optical lens, and improve the imaging quality of the optical lens. In addition, the assembly sensitivity of the optical lens can be reduced, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0052] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: 0.75 < f12 / f < 1.8. Satisfying the above range can reduce the aberration correction difficulty of the lens and improve the imaging quality of the optical lens. More specifically: 0.81 < f12 / f < 1.68.

[0053] In some embodiments, the optical total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.5 < TTL / f < 1.9; the optical total track 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: 2.3 < TTL / IH < 3.4. Satisfying the above ranges is beneficial to achieving a balance between a small volume and a large image surface of the optical lens, so that the lens has a smaller total length. More specifically: 1.62 < TTL / f < 1.88; 2.53 < TTL / IH < 3.31.

[0054] In some embodiments, 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: 0.9 < IH / EPD < 1.1; the real image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.5 < IH / f < 0.7. Satisfying the above ranges is beneficial to increasing the light quantity, so that the brightness of the peripheral field of view and the central field of view is more uniform. At the same time, controlling the image height and the focal length of the optical lens within a reasonable range is helpful to the optical lens having a large image surface and improving the imaging quality. More specifically: 0.95 < IH / EPD < 1.06; 0.56 < IH / f < 0.66.

[0055] In some embodiments, the first lens has a first lens material, and the second lens has a second lens material different from the first lens material. In some embodiments, the first lens material and the second lens material satisfy: 1.5 < n1 / n2 < 2.5, where n1 and n2 respectively represent the refractive index of the first lens material and the second lens material. Satisfying the above range is beneficial to improving the imaging quality of the optical lens. More specifically: 1.6 < n1 / n2 < 2.4.

[0056] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2 < f1 / f < -1.35; the object side surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: -0.45 < R1 / f < -0.25; and the image side surface curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: -0.7 < R2 / f < -0.4. Satisfying the above ranges, the proportion of the refractive power of the first lens and the surface shape thereof are reasonably limited, which can collect light at a large field of view to a large extent, so that the light enters the rear optical system, increases the light flux, and improves the field of view. More specifically, -1.86 < f1 / f < -1.39; -0.43 < R1 / f < -0.27; and -0.69 < R2 / f < -0.42.

[0057] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < f2 / f < 1; and the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < f4 / f < 0.7. Satisfying the above ranges, it is beneficial to achieve a larger amount of light, and increase the relative luminance. More specifically, 0.62 < f2 / f < 0.9; and 0.52 < f4 / f < 0.6.

[0058] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -0.7 < f3 / f < -0.4; the object side surface curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -4.8 < R5 / f < -2.7; and the image side surface curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 0.35 < R6 / f < 0.55. Satisfying the above ranges, the proportion of the refractive power of the third lens and the surface shape thereof are reasonably limited, which can effectively balance the aberration of the lens, and improve the imaging quality. More specifically, -0.67 < f3 / f < -0.47; -4.42 < R5 / f < -2.92; and 0.37 < R6 / f < 0.53.

[0059] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -2.7 < f7 / f < -1; the object side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -5.9 < R13 / f < -2.2; and the image side surface curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.9 < R14 / f < 5.4. Satisfying the above ranges, by reasonably limiting the proportion of the refractive power of the seventh lens and the surface shape thereof, the aberration generated at the front end of the lens can be effectively corrected, and the imaging quality of the lens is improved. More specifically, -2.63 < f7 / f < -1.07; -5.39 < R13 / f < -2.41; and 0.93 < R14 / f < 4.97.

[0060] In some embodiments, a combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and a combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -0.85 < f1234 / f5678 < -0.25; a combined focal length f34 of the third lens and the fourth lens and a combined focal length f56 of the fifth lens and the sixth lens satisfy: 0 < f34 / f56 < 9.5. Satisfying the above ranges can effectively correct chromatic aberration of the optical lens and reduce sensitivity to decentration. More specifically, -0.79 < f1234 / f5678 < -0.27; 0.02 < f34 / f56 < 8.82.

[0061] In some embodiments, a radius of curvature R5 of the object side surface of the third lens and a radius of curvature R6 of the image side surface of the third lens satisfy: 1.15 < (R5-R6) / (R5+R6) < 1.45; a radius of curvature R1 of the object side surface of the first lens and a radius of curvature R2 of the image side surface of the first lens satisfy: -5.4 < (R1+R2) / (R1-R2) < -3.6; a radius of curvature R7 of the object side surface of the fourth lens and a radius of curvature R8 of the image side surface of the fourth lens satisfy: -0.55 < (R7+R8) / (R7-R8) < -0.1; and a radius of curvature R13 of the object side surface of the seventh lens and a radius of curvature R14 of the image side surface of the seventh lens satisfy: |(R13+R14) / (R13-R14)| < 0.7. Satisfying the above ranges can correct aberration of the optical lens and ensure smooth light ray trend through the first, third, fourth and seventh lenses, thereby reducing tolerance sensitivity of the optical lens. More specifically, 1.25 < (R5-R6) / (R5+R6) < 1.36; -4.95 < (R1+R2) / (R1-R2) < -3.95; -0.51 < (R7+R8) / (R7-R8) < -0.14; and -0.35 < (R13+R14) / (R13-R14) < 0.65.

[0062] In some embodiments, a maximum field of view FOV of the optical lens and an aperture value Fno of the optical lens satisfy: 17° < FOV / Fno < 23°. Satisfying the above range can reasonably limit the ratio of the field of view and the aperture value, so as to collect light rays at a large angle and obtain good imaging quality. More specifically, 18.34° < FOV / Fno < 21°.

[0063] In some embodiments, a back focal length BFL of the optical lens and an effective focal length f of the optical lens satisfy: 0.15 < BFL / f < 0.29. Satisfying the above range can limit the optical lens to have a proper back focus, facilitate reasonable arrangement of positions of the lenses, and reduce processing and assembly difficulty.

[0064] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.5 < f5 / f < 0.7. Satisfying the above range, the ratio of the refractive power of the fifth lens is reasonably limited, which helps to flatten the light ray trend of the front end lens, corrects the aberration generated by the front end lens, and improves the imaging quality. More specifically: 0.51 < f5 / f < 0.65.

[0065] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -0.8 < f6 / f < -0.4. Satisfying the above range, the ratio of the refractive power of the sixth lens is reasonably limited, which can effectively improve the aberration of the edge field of view and improve the overall imaging quality of the optical lens. More specifically: -0.78 < f6 / f < -0.49.

[0066] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -7 < f8 / f < -1.2. Satisfying the above range, the ratio of the refractive power of the eighth lens is reasonably limited, which is beneficial to increase the degree of divergence of light and realize large target surface imaging. More specifically: -6.88 < f8 / f < -1.32.

[0067] In some embodiments, the combined focal length f34 of the third lens and the fourth lens and the effective focal length f of the optical lens satisfy: 1.7 < f34 / f < 17.5; the third lens and the fourth lens are cemented to form a cemented lens. Satisfying the above range is beneficial to realize the deflection of light and better realize the long-focus characteristics of the system. More specifically: 1.88 < f34 / f < 16.22.

[0068] In some embodiments, the combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.1 < f56 / f < 360; the fifth lens and the sixth lens are cemented to form a cemented lens. Satisfying the above range is beneficial to realize the deflection of light and better realize the long-focus characteristics of the system. More specifically: 1.19 < f56 / f < 353.13.

[0069] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -1.25 < f3 / f4 < -0.8. Satisfying the above range, the focal length relationship between the third lens and the fourth lens is reasonably set, which can diverge the light to a certain extent and is beneficial to realize large target surface imaging. More specifically: -1.15 < f3 / f4 < -0.89.

[0070] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -1.25 < f5 / f6 < -0.6. By satisfying the above range, the focal length relationship between the fifth lens and the sixth lens is reasonably set, which can diverge the light rays to a certain extent, which is beneficial to realize large target surface imaging. More specifically: -1.14 < f5 / f6 < -0.66.

[0071] In some embodiments, the optical lens satisfies the following conditional expressions: 19mm < f < 23mm; 30° < FOV < 35°; 11mm < EPD < 14mm; 34mm < TTL < 40mm; 1.5 < Fno < 1.8; 11mm < IH < 14mm; 19° < CRA < 25°; 3mm < BFL < 6mm. 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 incidence angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. By satisfying the above range, the optical lens has one or more advantages such as long focal length, large aperture, high imaging quality, etc. More specifically: 20.68mm < f < 21.39mm; 31.19° < FOV < 34.1°; 12.44mm < EPD < 12.97mm; 34.23mm < TTL < 39.99mm; 1.61 < Fno < 1.71; 12.07mm < IH < 13.47mm; 20.89° < CRA < 23.45°; 3.47mm < BFL < 5.84mm.

[0072] 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 characteristics of the glass itself. The optical lens provided by the present application can adopt a full-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0073] 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 the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, and the eighth lens of the present application adopt an aspherical lens, and the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens adopt a spherical lens.

[0074] 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:

[0075] ;

[0076] 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.

[0077] 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 merely 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 manners, and are included in the protection scope of the present application.

[0078] Embodiment 1

[0079] Please refer to Figure 1 , which is a structural schematic diagram of an optical lens 100 provided in 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 stop ST, a second lens L2, a third lens L3, 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.

[0080] The first lens L1 has a negative focal power, the object side surface S1 thereof is a concave surface, and the image side surface S2 thereof is a convex surface.

[0081] The second lens L2 has a positive focal power, the object side surface S3 thereof is a convex surface, and the image side surface S4 thereof is a convex surface.

[0082] The third lens L3 has a negative focal power, the object side surface S5 thereof is a concave surface, and the image side surface S6 thereof is a concave surface.

[0083] The fourth lens L4 has a positive focal power, the object side surface S6 thereof is a convex surface, and the image side surface S7 thereof is a convex surface.

[0084] The third lens L3 and the fourth lens L4 form a cemented lens group, and the cemented surface of the image side surface of the third lens L3 and the object side surface of the fourth lens L4 is S6.

[0085] The fifth lens L5 has a positive focal power, the object side surface S8 thereof is a convex surface, and the image side surface S9 thereof is a convex surface.

[0086] The sixth lens L6 has negative focal power, the object side S9 is a concave surface, and the image side S10 is a concave surface;

[0087] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S9;

[0088] The seventh lens L7 has negative focal power, the object side S11 is a concave surface, and the image side S12 is a concave surface;

[0089] The eighth lens L8 has negative focal power, the object side S13 is a concave surface, and the image side S14 is a convex surface;

[0090] The object side S15 and the image side S16 of the filter G1 are both flat surfaces;

[0091] The object side S17 and the image side S18 of the protective glass G2 are both flat surfaces;

[0092] The imaging surface S19 is a flat surface.

[0093] The first lens L1, the second lens L2, and the eighth lens L8 are glass aspheric lenses, and the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses.

[0094] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0095] Table 1-1

[0096]

[0097] The surface type parameters of the aspheric lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0098] Table 1-2

[0099]

[0100] In this embodiment, the MTF curve of the optical lens 100 is shown in Figure 2 .

[0101] 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 the present 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.

[0102] Embodiment 2

[0103] Please refer to Figure 3 , which is a structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present application. Compared with Embodiment 1, the main difference is that the image side S4 of the second lens L2 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0104] The related parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0105] Table 2-1

[0106]

[0107] The surface type parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0108] Table 2-2

[0109]

[0110] In this embodiment, the MTF curve of the optical lens 200 is shown in Figure 4 . It can be seen from Figure 4 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.

[0111] Embodiment 3

[0112] 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 image side S14 of the eighth lens L8 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0113] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0114] Table 3-1

[0115]

[0116] The surface type parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0117] Table 3-2

[0118]

[0119] In the embodiment, a MTF curve of the optical lens 300 is as shown in Figure 6 From Figure 6 it can be seen that the MTF value of the 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.

[0120] Embodiment 4

[0121] Referring to Figure 7 , a structure schematic diagram of an optical lens 400 provided in the embodiment 4 of the present application is shown, and the main difference between the embodiment and the embodiment 1 is that: the object side S13 of the eighth lens L8 is a convex surface, and the image side S14 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0122] The related parameters of each lens in the optical lens 400 in the embodiment 4 are shown in Table 4-1.

[0123] Table 4-1

[0124]

[0125] The surface type parameters of the aspheric lens of the optical lens 400 in the embodiment 4 are shown in Table 4-2.

[0126] Table 4-2

[0127]

[0128] In the embodiment, a MTF curve of the optical lens 400 is as shown in Figure 8 From Figure 8 it can be seen that the MTF value of the 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.

[0129] Embodiment 5

[0130] Referring to Figure 9 , a structure schematic diagram of an optical lens 500 provided in the embodiment 5 of the present application is shown, and the main difference between the embodiment and the embodiment 1 is that: the image side S4 of the second lens L2 is a concave surface; the image side S14 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.

[0131] The related parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0132] Table 5-1

[0133]

[0134] The surface type parameters of the aspheric lens of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0135] Table 5-2

[0136]

[0137] In this embodiment, the MTF curve of the optical lens 600 is shown in Figure 10 From Figure 10 it can be seen that the MTF value of this embodiment is above 0.3 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.

[0138] Embodiment 6

[0139] 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 image side surface S4 of the second lens L2 is a concave surface; the object side surface S13 of the eighth lens L8 is a convex surface, and the image side surface S14 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0140] The related parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0141] Table 6-1

[0142]

[0143] The surface type parameters of the aspheric lens of the optical lens 600 in Embodiment 6 are shown in Table 6-2.

[0144] Table 6-2

[0145]

[0146] In this embodiment, the MTF curve of the optical lens 600 is shown in Figure 12 From Figure 12It can be seen that the MTF value of the 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.

[0147] Please refer to Table 7-1 and Table 7-2, the optical characteristics corresponding to each of the above embodiments, including the effective focal length f of the optical lens, the total optical 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 value corresponding to each conditional expression in each embodiment.

[0148] Table 7-1

[0149]

[0150] Table 7-2

[0151]

[0152] In summary of the above embodiments, the optical lens provided by the present application adopts eight lenses with specific optical power, 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 long focal length, large aperture, high imaging quality, etc.

[0153] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present 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.

[0154] The above-described embodiments only express several embodiments of the present application, which are described in a more specific and detailed manner, but should not be understood as limiting the scope of the present patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. An optical lens, eight pieces of lenses with optical power, characterized in that, In order from the object side to the imaging surface along the optical axis, successively comprise: a first lens with negative focal power, the object side surface of which is concave, and the image side surface of which is convex; a second lens with positive focal power, the object side surface of which is convex; a third lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave; a fourth lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex; a fifth lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex; a sixth lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave; a seventh lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave; an eighth lens with negative focal power; wherein the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: 0.75 < f12 / f < 1.

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: 1.5 < TTL / f < 1.9; 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: 2.3 < TTL / IH < 3.

4.

3. The optical lens of claim 1, wherein, 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: 0.9 < IH / EPD < 1.1; 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: 0.5 < IH / f < 0.

7.

4. The optical lens of claim 1, wherein, 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: 3.5 < d1 / (IH / 2) / Tan(FOV / 2) < 4.5; the combined focal length f12 of the first lens and the second lens and the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens satisfy: 0.8 < f12 / f1234 < 1.

8.

5. The optical lens of claim 1, wherein, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2 < f1 / f < -1.35; the object side surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: -0.45 < R1 / f < -0.25; the image side surface curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: -0.7 < R2 / f < -0.

4.

6. The optical lens of claim 1, wherein, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < f2 / f < 1; the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < f4 / f < 0.

7.

7. The optical lens of claim 1, wherein, The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -0.7 < f3 / f < -0.4; the object side surface curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -4.8 < R5 / f < -2.7; the image side surface curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 0.35 < R6 / f < 0.

55.

8. The optical lens of claim 1, wherein, A focal length f7 of the seventh lens and an effective focal length f of the optical lens satisfy: -2.7 < f7 / f < -1; a radius of curvature R13 on an object side of the seventh lens and the effective focal length f of the optical lens satisfy: -5.9 < R13 / f < -2.2; and a radius of curvature R14 on an image side of the seventh lens and the effective focal length f of the optical lens satisfy: 0.9 < R14 / f < 5.

4.

9. The optical lens of claim 1, wherein, A combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and a combined focal length f5678 of the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -0.85 < f1234 / f5678 < -0.25; and a combined focal length f34 of the third lens and the fourth lens and a combined focal length f56 of the fifth lens and the sixth lens satisfy: 0 < f34 / f56 < 9.

5.

10. The optical lens of claim 1, wherein, The optical lens satisfies at least one of the following conditional expressions: a radius of curvature R5 on an object side of the third lens and a radius of curvature R6 on an image side of the third lens satisfy: 1.15 < (R5-R6) / (R5+R6) < 1.45; or a radius of curvature R1 on an object side of the first lens and a radius of curvature R2 on an image side of the first lens satisfy: -5.4 < (R1+R2) / (R1-R2) < -3.6; or a radius of curvature R7 on an object side of the fourth lens and a radius of curvature R8 on an image side of the fourth lens satisfy: -0.55 < (R7+R8) / (R7-R8) < -0.1; or a radius of curvature R13 on an object side of the seventh lens and a radius of curvature R14 on an image side of the seventh lens satisfy: |(R13+R14) / (R13-R14)| < 0.7.

Images