Optical lens

Abstract

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

Description

TECHNICAL FIELD

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

[0002] With the continuous improvement of people's requirements for driving experience, vehicle application type optical lenses are increasingly used in intelligent driving, and vehicle optical lenses are continuously improving in the automotive industry.

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

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens with the advantages of excellent imaging quality.

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

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

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

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

[0009] The third lens with positive focal power, the object side surface is convex;

[0010] The fourth lens with positive focal power, the image side surface is convex;

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

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

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

[0014] Wherein, the object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: 0.3<(R13-R14) / (R13+R14)<0.85.

[0015] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.7 < TTL / f < 9; 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: 3.9 < TTL / IH < 4.1.

[0016] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.7 < TTL / f < 9; 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: 3.9 < TTL / IH < 4.1.

[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: 2.1 < IH / f < 2.3; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.85 < BFL / f < 1.4.

[0018] Further preferably, the object side half aperture radius d1 of the first lens, the real image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.55 < d1 / (IH / 2) / tan(FOV / 2) < 0.63; the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: 2.2 < f4567 / f < 3.6.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -29 < f2 / f < -11; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 3.5 < f3 / f < 7.3.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.9 < f5 / f < 6; the object side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: 1.5 < R9 / f < 2.6; the image side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 12 < R10 / f < 25.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 6 < f7 / f < 19; the object side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -30 < R13 / f < -17; the image side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -9 < R14 / f < -3.

[0022] It is further preferred that the object-side surface curvature radius R9 of the fifth lens and the image-side surface curvature radius R10 of the fifth lens satisfy: -0.85 < (R9-R10) / (R9+R10) < -0.6; the object-side surface curvature radius R9 of the fifth lens and the image-side surface curvature radius R10 of the fifth lens satisfy: 0.08 < R9 / R10 < 0.22.

[0023] It is further preferred that the object-side surface half-field radius of the seventh lens d13 and the object-side surface sagittal height Sag13 of the seventh lens satisfy: -0.07 < Sag13 / d13 < -0.01; the image-side surface half-field radius of the seventh lens d14 and the image-side surface sagittal height Sag14 of the seventh lens satisfy: -0.18 < Sag14 / d14 < -0.03.

[0024] The optical lens provided by the application adopts seven lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages of large field of view, large image surface, large aperture, 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 F-Tan(Theta) distortion curve diagram of the optical lens according to the embodiment of the present application.

[0028] Figure 3 FIG. 3 is an MTF curve diagram of the optical lens according to the embodiment of the present application.

[0029] Figure 4 FIG. 4 is an axial aberration curve diagram of the optical lens according to the embodiment of the present application.

[0030] Figure 5 FIG. 5 is a structural schematic diagram of an optical lens according to another embodiment of the present application.

[0031] Figure 6 FIG. 6 is an F-Tan(Theta) distortion curve diagram of the optical lens according to the embodiment of the present application.

[0032] Figure 7 FIG. 7 is an MTF curve diagram of the optical lens according to the embodiment of the present application.

[0033] Figure 8The axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0034] Figure 9 The structure diagram of the optical lens in Embodiment 3 of the present application.

[0035] Figure 10 The F-Tan(Theta) distortion curve of the optical lens in Embodiment 3 of the present application.

[0036] Figure 11 The MTF curve of the optical lens in Embodiment 3 of the present application.

[0037] Figure 12 The axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0038] Figure 13 The structure diagram of the optical lens in Embodiment 4 of the present application.

[0039] Figure 14 The F-Tan(Theta) distortion curve of the optical lens in Embodiment 4 of the present application.

[0040] Figure 15 The MTF curve of the optical lens in Embodiment 4 of the present application.

[0041] Figure 16 The axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0042] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0043] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of embodiments of the present application and is not intended to limit the scope of the present application in any way. Throughout the specification, like reference numerals refer to like elements. The expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0044] It should be noted that, in the present specification, the expressions first, second, third, and the like are merely 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.

[0045] In the drawings, the thickness, size, and shape of the lenses have been exaggerated slightly for ease of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0046] In this document, 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.

[0047] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, mean that something is present, but do not exclude the presence of one or more additional features, elements, components, and / or groups thereof. In addition, when describing the embodiments of the present application, the use of "may" means that one or more embodiments of the present application. Also, the word "exemplary" is intended to mean an example or an illustration.

[0048] 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 should also be understood that the terms 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.

[0049] 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 the embodiments.

[0050] The optical lens provided by the embodiments of the present application is composed of seven lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface as the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens.

[0051] In some embodiments, the first lens can have a negative focal power, a convex object side surface, and a concave image side surface. The second lens can have a negative focal power, a concave object side surface, and a convex image side surface. The third lens can have a positive focal power, a convex object side surface, and a convex or concave image side surface. The fourth lens can have a positive focal power, a convex or concave object side surface, and a convex image side surface. The fifth lens can have a positive focal power, a convex object side surface, and a concave image side surface. The sixth lens can have a negative focal power, a convex object side surface, and a concave image side surface. The seventh lens can have a positive focal power, a concave object side surface, and a convex image side surface.

[0052] In some embodiments, the optical lens can further include a stop, which can be located between the third lens and the fourth lens. It can be understood that the stop is used to limit the amount of light to change the brightness of the image. In addition, when the stop is located between the third lens and the fourth lens, the stop can reasonably distribute the functions of the first lens to the seventh lens, for example, the first lens, the second lens and the third lens can be used to receive light to a greater extent, and the fourth lens to the seventh lens can be used to correct the function of aberration, which is conducive to balancing the structure of the entire optical system. In addition, when the stop is located between the third lens and the fourth lens, the stop aberration correction is facilitated.

[0053] In some embodiments, the optical lens can further include a filter and a protective glass, which are sequentially arranged between the seventh lens and the imaging surface along the optical axis. The filter is used to filter out interference light to prevent interference light from reaching the imaging surface of the optical lens and affecting 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.

[0054] In some embodiments, the object side surface radius of curvature R13 of the seventh lens and the image side surface radius of curvature R14 of the seventh lens satisfy: 0.3<(R13-R14) / (R13+R14)<0.85. By reasonably controlling the shape of the seventh lens, the light deflection angle is reduced, the light reaching the image surface is stable, and the imaging quality of the optical lens is effectively improved. More specifically, 0.33<(R13-R14) / (R13+R14)<0.82.

[0055] In some embodiments, the optical total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.7 < TTL / f < 9; the optical total track length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 3.9 < TTL / IH < 4.1. Satisfying the above ranges helps to ensure sufficient space to adjust the structures of the lenses inside the optical lens, optimize the imaging effect, and balance the requirements of the image size and the overall size of the optical lens, and can improve the overall structural stability of the optical lens. More specifically, 8.75 < TTL / f < 8.97, 3.98 < TTL / IH < 4.07.

[0056] In some embodiments, the maximum field angle of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 88° < FOV / Fno < 91°; the real image height IH corresponding to the maximum field angle of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.5 < IH / EPD < 3.7. Satisfying the above ranges is conducive to expanding the field angle of view of the optical lens and increasing the aperture of the optical lens, which is conducive to the optical lens to obtain more scene information, meet the requirement of large range detection, and the realization of large aperture characteristics is conducive to improving the problem of rapid decline of relative luminance at the edge of the field of view, so as to also be conducive to obtaining more scene information, and increasing the width of the light beam entering the optical lens, so that the brightness of the optical lens at the image plane is improved to avoid dark corners, and the relative luminance at the edge of the image plane of the optical lens is improved. More specifically, 88.68° < FOV / Fno < 90.69°, 3.52 < IH / EPD < 3.63.

[0057] In some embodiments, the real image height IH corresponding to the maximum field angle of view of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.3; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.85 < BFL / f < 1.4. Satisfying the above ranges helps to realize the large image plane characteristic, improve the imaging quality of the optical lens, and helps the optical lens to have a suitable back focal length, which facilitates the reasonable arrangement of the positions of the lenses, while reducing the processing and assembly difficulty. More specifically, 2.15 < IH / f < 2.26, 0.86 < BFL / f < 1.31.

[0058] In some embodiments, the first lens satisfies 0.55 < d1 / (IH / 2) / tan(FOV / 2) < 0.63, the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy 2.2 < f4567 / f < 3.6, and the second lens satisfies -29 < f2 / f < -11. The ranges can effectively control the front and rear diameters of the optical lens, improve the structural stability of the optical lens, and reasonably control the focal length ratio of the fourth lens, the fifth lens, the sixth lens and the seventh lens of the optical lens, which is helpful to balance the lens aberration and improve the imaging quality. More specifically, 2.22 < f4567 / f < 3.52 and -28.09 < f2 / f < -11.93.

[0059] In some embodiments, the optical lens satisfies -29 < f2 / f < -11, the third lens satisfies 3.5 < f3 / f < 7.3, and the second lens satisfies -29 < f2 / f < -11. The ranges can effectively control the front and rear diameters of the optical lens, improve the structural stability of the optical lens, and reasonably control the focal length ratio of the fourth lens, the fifth lens, the sixth lens and the seventh lens of the optical lens, which is helpful to balance the lens aberration and improve the imaging quality. More specifically, 2.22 < f4567 / f < 3.52 and 3.54 < f3 / f < 7.3.

[0060] In some embodiments, the optical lens satisfies 2.9 < f5 / f < 6, the fifth lens satisfies 1.5 < R9 / f < 2.6, the fifth lens satisfies 12 < R10 / f < 25, and the fifth lens satisfies 2.9 < f5 / f < 6. The ranges can effectively control the front and rear diameters of the optical lens, improve the structural stability of the optical lens, and reasonably control the focal length ratio of the fourth lens, the fifth lens, the sixth lens and the seventh lens of the optical lens, which is helpful to balance the lens aberration and improve the imaging quality. More specifically, 2.96 < f5 / f < 5.65, 1.56 < R9 / f < 2.59, and 12.22 < R10 / f < 24.45.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 6 < f7 / f < 19; the object-side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -30 < R13 / f < -17; and the image-side surface curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -9 < R14 / f < -3. Satisfying the above ranges, by reasonably allocating the proportion of the positive refractive power of the seventh lens, the brightness of the edge field of view can be improved, and the dark corner can be avoided. By limiting the shape of the object-side surface and the image-side surface of the seventh lens, the degree of deflection of light can be slowed down, and aberration can be reduced. More specifically, 6.05 < f7 / f < 18.02, -29.33 < R13 / f < -17.12, and -8.51 < R14 / f < -3.08.

[0062] In some embodiments, the object-side surface curvature radius R9 of the fifth lens and the image-side surface curvature radius R10 of the fifth lens satisfy: -0.85 < (R9-R10) / (R9+R10) < -0.6; and the object-side surface curvature radius R9 of the fifth lens and the image-side surface curvature radius R10 of the fifth lens satisfy: 0.08 < R9 / R10 < 0.22. Satisfying the above ranges, by reasonably limiting the shape of the object-side surface and the image-side surface of the fifth lens, the lens aberration can be further balanced, the imaging quality can be improved, and the difficulty of aberration correction of the rear-end lens can be reduced. More specifically, -0.84 < (R9-R10) / (R9+R10) < -0.64.

[0063] In some embodiments, the object-side surface half-aperture radius d13 of the seventh lens and the object-side surface sagittal height Sag13 of the seventh lens satisfy: -0.07 < Sag13 / d13 < -0.01; and the image-side surface half-aperture radius d14 of the seventh lens and the image-side surface sagittal height Sag14 of the seventh lens satisfy: -0.18 < Sag14 / d14 < -0.03. Satisfying the above ranges, the trend of the light rays at the edge field of view can be controlled, and the details of the central field of view of the light rays can be highlighted.

[0064] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively satisfy: 0.46 < ∑CT / TTL < 0.54; and the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.1 < ∑CT / f < 4.7. Satisfying the above ranges, high-pixel characteristics can be achieved, the imaging quality of the optical lens can be improved, and the production cost can be reduced. More specifically: 4.14 < ∑CT / f < 4.64.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.5 < f1 / f < -2. The above range helps to achieve a large angle of light collection and obtain more picture information by reasonably limiting the proportion of negative optical power of the first lens. More specifically, -2.42 < f1 / f < -2.02.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.4 < f4 / f < 4. The above range helps to reduce the field curvature of the optical lens and improve the imaging quality by reasonably limiting the proportion of positive optical power of the fourth lens. More specifically, 2.41 < f4 / f < 3.89.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.6 < f6 / f < -2; the object side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 7 < R11 / f < 20; the image side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 1.7 < R12 / f < 2.1. The above range helps to increase the imaging area of the lens and improve the imaging quality by reasonably allocating the proportion of negative optical power of the sixth lens, and helps to reduce the high-order aberration of the optical lens and improve the imaging quality by limiting the shape of the object side and the image side of the sixth lens. More specifically, -2.57 < f6 / f < -2.02, 7.29 < R11 / f < 19.34, 1.78 < R12 / f < 2.07.

[0068] In some embodiments, the optical lens satisfies the following conditional expressions: 4mm < f < 4.2mm; 144° < FOV < 150°; 2.5mm < EPD < 2.6mm; 36mm < TTL < 37mm; 1.6 < Fno < 1.7; 8.9mm < IH < 9.1mm; 17° < CRA < 27°; 3.5mm < BFL < 5.5mm. 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 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 a large field of view angle, a large image surface, a large aperture, high imaging quality, and the like. More specifically, 4.04mm < f < 4.19mm; 2.5mm < EPD < 2.57mm; 36.01mm < TTL < 36.62mm; 1.6 < Fno < 1.65; 17.38° < CRA < 26.67°; 3.5mm < BFL < 5.46mm; 144.9° < FOV < 146.1°; 8.96mm < IH < 9.1mm.

[0069] 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. 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.

[0070] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt a spherical lens or an aspherical lens. Compared with a spherical structure, an 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 lens miniaturization. More specifically, the first lens, the second lens, the third lens, the fifth lens, and the sixth lens of the present application adopt a spherical lens, the fourth lens adopts an aspherical lens, and the seventh lens can adopt a spherical lens or an aspherical lens.

[0071] 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:

[0072]

[0073] Wherein, z is the distance of the curved surface and the curved surface vertex 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 curved surface vertex, K is the quadratic curved surface coefficient, B, C, D, E, F are the fourth order, sixth order, eighth order, tenth order, twelfth order curved surface coefficient respectively.

[0074] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, any changes, substitutions, combinations or simplifications made without departing from the innovative points of the application should be regarded as equivalent replacement, and are included in the protection scope of the application.

[0075] Embodiment 1

[0076] 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, along the optical axis from the object side to the imaging surface, a first lens L1, a second lens L2, a third lens L3, a diaphragm ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter G1.

[0077] The first lens L1 has negative focal power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface;

[0078] The second lens L2 has negative focal power, the object side surface S3 is a concave surface, and the image side surface S4 is a convex surface;

[0079] The third lens L3 has positive focal power, the object side surface S5 is a convex surface, and the image side surface S6 is a concave surface;

[0080] The fourth lens L4 has positive focal power, the object side surface S7 and the image side surface S8 are both convex surfaces;

[0081] The fifth lens L5 has positive focal power, the object side surface S9 is a convex surface, and the image side surface S10 is a concave surface;

[0082] The sixth lens L6 has negative focal power, the object side surface S11 is a convex surface, and the image side surface S12 is a concave surface;

[0083] The seventh lens L7 has positive focal power, the object side surface S13 is a concave surface, and the image side surface S14 is a convex surface;

[0084] The object side surface S15 and the image side surface S16 of the filter G1 are both flat surfaces;

[0085] The object side surface S17 and the image side surface S18 of the protective glass G2 are both flat surfaces;

[0086] The imaging plane S19 is a plane.

[0087] The first lens L1, the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses, while the fourth lens L4 is a glass aspherical lens.

[0088] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0089] Table 1-1

[0090]

[0091]

[0092] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0093] Table 1-2

[0094] Surface number K B C D E F S7 -2.84E-01 -9.93E-04 4.29E-05 -1.10E-05 9.04E-07 -2.87E-08 S8 2.99E+00 4.08E-04 -1.25E-05 9.33E-07 -3.51E-08 7.87E-10

[0095] In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and axial aberration curve of the optical lens 100 are as follows: Figures 2 to 4 As shown.

[0096] Figure 2 The F-Tan(Theta) distortion curves for Example 1 are shown, representing the F-Tan(Theta) distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tan(Theta) distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tan(Theta) distortion of the optical lens is controlled within -70% to 0, indicating that the optical lens can effectively correct distortion.

[0097] Figure 3 The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.3 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0098] Figure 4The axial aberration curve of the embodiment 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the shift amount of the axial aberration is controlled within -0.02mm-0.05mm, which shows that the optical lens 100 can better correct the axial aberration.

[0099] Embodiment 2

[0100] Referring to Figure 5 , a structure schematic diagram of the optical lens 200 provided in the embodiment 2 of the present application is shown, and the main difference between the present embodiment and the embodiment 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0101] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0102] Table 2-1

[0103]

[0104]

[0105] The surface type parameters of the aspherical lens of the optical lens 200 in the embodiment 2 are shown in Table 2-2.

[0106] Table 2-2

[0107] Surface number K B C D E F S7 4.99E+01 -4.37E-04 -8.19E-05 1.20E-05 -8.71E-07 2.44E-08 S8 1.48E+00 4.58E-04 3.57E-06 5.85E-07 -2.36E-08 9.02E-10

[0108] In the present embodiment, the F-Tan(Theta) distortion curve, the MTF curve and the axial aberration curve of the optical lens 200 are shown in Figures 6 to 8 .

[0109] As can be seen from Figure 6 , the F-Tan(Theta) distortion of the optical lens is controlled within -70%-0, which shows that the distortion of the optical lens 200 is better corrected.

[0110] As can be seen from Figure 7 , the MTF value of the present embodiment is above 0.35 in the full field of view, and in the range of 0-120lp / mm, the MTF curve is uniformly and smoothly decreased 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] As can be seen from Figure 8 , the shift amount of the axial aberration is controlled within -0.02mm-0.06mm, which shows that the optical lens 200 can better correct the axial aberration.

[0112] Example 3

[0113] Please see Figure 9 The figure shown is a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0114] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0115] Table 3-1

[0116]

[0117] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0118] Table 3-2

[0119] Surface number K B C D E F S7 2.14E+00 -1.02E-03 5.22E-05 -1.11E-05 8.61E-07 -2.56E-08 S8 2.91E+00 4.19E-04 -1.97E-06 2.46E-07 -1.53E-09 3.49E-10

[0120] In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and axial aberration curve of the optical lens 300 are as follows: Figures 10 to 12 As shown.

[0121] from Figure 10 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -70% to 0, indicating that the distortion of the optical lens 300 has been well corrected.

[0122] from Figure 11 As can be seen, the MTF value of this embodiment is above 0.35 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0123] from Figure 12 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.06mm, indicating that the optical lens 300 can correct axial aberration well.

[0124] Example 4

[0125] Please see Figure 13 The figure shown is a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0126] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0127] Table 4-1

[0128]

[0129]

[0130] The surface shape parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0131] Table 4-2

[0132] Surface number K B C D E F S7 1.18E+00 -7.56E-04 2.38E-05 -4.98E-06 2.06E-07 -3.99E-09 S8 3.54E+00 7.47E-04 -2.30E-05 2.57E-06 -1.54E-07 4.17E-09 S13 -4.97E+01 -6.70E-04 -4.93E-05 -1.90E-07 5.22E-08 0.00E+00 S14 -1.86E+01 8.67E-05 -8.07E-06 7.34E-07 4.68E-08 0.00E+00

[0133] In this embodiment, the F-Tan(Theta) distortion curve, the MTF curve and the axial aberration curve of the optical lens 400 are shown in Figures 14 to 16

[0134] As can be seen from Figure 14 , the F-Tan(Theta) distortion of the optical lens is controlled within -70%~0, which shows that the distortion of the optical lens 400 is well corrected.

[0135] As can be seen from Figure 15 , the MTF value of this embodiment is above 0.4 in the full field of view, and in the range of 0~120 lp / mm, the MTF curve is uniformly and smoothly decreased 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.

[0136] As can be seen from Figure 16 , the shift of the axial aberration is controlled within -0.04mm~0.04mm, which shows that the optical lens 400 can well correct the axial aberration.

[0137] Please refer to Table 5, for the optical properties corresponding to each embodiment described above, including the effective focal length f, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV and the numerical value corresponding to each conditional expression in each embodiment of the optical lens.

[0138] Table 5

[0139]

[0140]

[0141] ​In summary, the optical lens provided by the present application adopts seven lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages of large field of view, large image surface, large aperture, high imaging quality, and the like.

[0142] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0143] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent 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, and these all belong to 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, in total seven pieces of lenses, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is concave and whose image side is convex; A third lens with a positive optical power, whose object side is convex; A fourth lens with a positive optical power, whose image side is convex; A fifth lens with a positive optical power, whose object side is convex and whose image side is concave; A sixth lens with a negative optical power, whose object side is convex and whose image side is concave; A seventh lens with a positive optical power, whose object side is concave and whose image side is convex; Wherein, 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: 0.3 < (R13 - R14) / (R13 + R14) < 0.85; The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.7 < TTL / f < 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: 3.9 < TTL / IH < 4.

1.

2. The optical lens of claim 1, wherein, 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: 0.33 < (R13 - R14) / (R13 + R14) < 0.82; The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.75 < TTL / f < 8.97; 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: 3.98 < TTL / IH < 4.

07.

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: 88° < FOV / Fno < 91°; 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 < 3.

7.

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: 2.1 < IH / f < 2.3; The effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.85 < BFL / f < 1.

4.

5. The optical lens according to claim 1, characterized in that, The clear aperture radius d1 of the object side 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: 0.55 < d1 / (IH / 2) / tan(FOV / 2) < 0.63; The combined focal length f4567 of the fourth, fifth, sixth, and seventh lenses and the effective focal length f of the optical lens satisfy: 2.2 < f4567 / f < 3.

6.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -29 < f2 / f < -11; The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 3.5 < f3 / f < 7.

3.

7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.9 < f5 / f < 6; the curvature radius R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1.5 < R9 / f < 2.6; the curvature radius R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 12 < R10 / f < 25.

8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 6 < f7 / f < 19; the curvature radius R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -30 < R13 / f < -17; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -9 < R14 / f < -3.

9. The optical lens according to claim 1, characterized in that, 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: -0.85 < (R9 - R10) / (R9 + R10) < -0.6; 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: 0.08 < R9 / R10 < 0.

22.

10. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d13 of the object side surface of the seventh lens and the sagitta Sag13 of the clear aperture of the object side surface of the seventh lens satisfy: -0.07 < Sag13 / d13 < -0.01; the clear aperture semi-diameter d14 of the image side surface of the seventh lens and the sagitta Sag14 of the clear aperture of the image side surface of the seventh lens satisfy: -0.18 < Sag14 / d14 < -0.03.

Images