Optical lens

Abstract

The invention provides an optical lens, which comprises seven lenses, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface, the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; 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 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. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of a large field angle, a large target surface, a large aperture, high imaging quality and the like.

Description

Technical Field

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

[0002] With the continuous improvement of people's requirements for driving experience, in-vehicle application optical lenses are increasingly used in intelligent driving, and the status of in-vehicle optical lenses in the automotive-related industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play an important role in intelligent driving. It collects environmental information through various lenses and sensors to ensure the driving safety of drivers. In addition to requiring the optical lens to have a thin, light, short and small shape and high pixel and high resolution characteristics, the existing ADAS system lenses also require the optical lens to be able to clearly image under low illuminance conditions. Therefore, it is necessary to develop an optical lens with good imaging effect. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

[0005] The technical solution adopted by the present invention is as follows: An optical lens, comprising a total of seven lenses, which successively include from the object side to the imaging surface along the optical axis: A first lens with negative optical power, its object side is convex, and its image side is concave; A second lens with negative optical power, its object side is concave, and its image side is convex; A third lens with positive optical power, its object side is convex, and its image side is concave; A fourth lens with positive optical power, its object side is convex, and its image side is convex; A fifth lens with positive optical power, its object side is convex, and its image side is convex; A sixth lens with negative optical power, its object side is convex, and its image side is concave; A seventh lens with positive optical power, its object side is concave, and its image side is convex; Wherein, the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 1; 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: 0.6 < (R13 - R14) / (R13 + R14) < 1.

[0006] More preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7 < TTL / f < 9; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 4.2.

[0007] More preferably, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 80° < FOV / Fno < 90°; the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.6 < IH / EPD < 4.1.

[0008] More preferably, the true 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: 2.15 < IH / f < 2.5; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.9 < BFL / f < 1.3.

[0009] More preferably, the clear aperture radius d1 of the object side of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.57 < d1 / (IH / 2) / tan(FOV / 2) < 0.7; the combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: -4.1 < f123 / f4567 < -1.8.

[0010] More preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -1.7; the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -9.5 < f2 / f < -7.5.

[0011] More preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.2 < f5 / f < 2.6; the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side of the fifth lens satisfy: |(R9 + R10) / (R9 - R10)| < 0.2.

[0012] More preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2 < f6 / f < -1.8; the radius of curvature R11 of the object side of the sixth lens and the effective focal length f of the optical lens satisfy: 7 < R11 / f < 19; the radius of curvature R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: 1.4 < R12 / f < 1.7.

[0013] More preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 6 < f7 / f < 8; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -33 < R13 / f < -21; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -4 < R14 / f < -3.1.

[0014] More preferably, the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 0.66 < (R11 - R12) / (R11 + R12) < 0.85; the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 0.71 < (R13 - R14) / (R13 + R14) < 0.81.

[0015] The optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as a large field of view angle, a large target surface, a large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, wherein: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 2 is the field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 is the axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 is the lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 is the MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0022] Figure 7 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 8 It is the field curvature curve graph of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 It is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 10 It is the axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 11 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0027] Figure 12 It is the MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0028] Figure 13 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 It is the field curvature curve graph of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 It is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 It is the axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 17 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 18 It is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0034] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0035] To better understand the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another, and do not represent any limitation on the features. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0037] In the drawings, for the sake of convenience of illustration, the thickness, size and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0038] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0039] It should also be understood that the terms "comprising", "including", "having", "containing" and / or "including" when used in this specification mean the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when an expression such as "at least one of..." appears after the list of listed features, it modifies the entire list of listed features, rather than an individual element in the list. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0040] 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 terms (such as those defined in a common dictionary) should be interpreted as having a meaning 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.

[0041] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine with the embodiments to detail this application.

[0042] The optical lens provided by the embodiment of the present invention has a total of seven lenses, which are, in order from the object side to the imaging surface along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens.

[0043] In some embodiments, the first lens may have a negative optical power, with its object side being convex and its image side being concave. The second lens may have a negative optical power, with its object side being concave and its image side being convex. The third lens may have a positive optical power, with its object side being convex and its image side being concave. The fourth lens may have a positive optical power, with its object side being convex and its image side being convex. The fifth lens may have a positive optical power, with its object side being convex and its image side being convex. The sixth lens may have a negative optical power, with its object side being convex and its image side being concave. The seventh lens may have a positive optical power, with its object side being concave and its image side being convex.

[0044] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging. In addition, when the diaphragm is located between the third lens and the fourth lens, the diaphragm 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 aberrations, which is beneficial to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the third lens and the fourth lens, it is convenient to correct the diaphragm aberration.

[0045] In some embodiments, the optical lens may further include a filter and a protective glass, and the filter and the protective glass may be sequentially arranged along the optical axis between the seventh lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering 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 almost no impact on the imaging quality of the optical lens.

[0046] In some embodiments, the radius of curvature R11 of the object side of the sixth lens and the radius of curvature R12 of the image side of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 1. Satisfying the above range is beneficial to increasing the divergence degree of light, increasing the area of light entering the imaging surface, realizing large-format imaging of the lens, and improving the imaging quality of the optical lens. More specifically, 0.66 < (R11 + R12) / (R11 - R12) < 0.85.

[0047] In some embodiments, the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 0.6 < (R13 - R14) / (R13 + R14) < 1. Meeting the above range reduces the height of the light incident on the rear, avoids the light energy loss caused by the excessive chief ray angle of the large field of view light when reaching the imaging surface, is conducive to improving the illuminance of the edge field of view, and is beneficial to achieving a short overall optical length. More specifically, 0.71 < (R13 - R14) / (R13 + R14) < 0.81.

[0048] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7 < TTL / f < 9. Meeting the above range can effectively limit the length of the lens and is beneficial to the miniaturization of the optical lens. More specifically, 7.71 < TTL / f < 8.85.

[0049] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 4.2. Meeting the above range ensures that, with the same overall length of the lens, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging, and better realizes the balance between the small overall length and the large image plane of the lens. More specifically, 3.37 < TTL / IH < 3.97.

[0050] In some embodiments, the maximum field of view angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 80° < FOV / Fno < 90°. Meeting the above range limits the optical lens to have an appropriate field of view angle and f-number, can collect light at a large angle, and obtain good imaging quality. More specifically, 83.32° < FOV / Fno < 87.28°.

[0051] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.6 < IH / EPD < 4.1. Meeting the above range can increase the width of the light beam incident on the optical lens, improve the brightness of the optical lens at the image plane, and avoid vignetting. More specifically, 3.67 < IH / EPD < 3.89.

[0052] In some embodiments, the true 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: 2.15 < IH / f < 2.5. Meeting the above range controls the image height and focal length of the optical lens within a reasonable range, helps the optical lens to have the characteristic of a large image plane, and improves the imaging quality. More specifically, 2.19 < IH / f < 2.29.

[0053] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.9 < BFL / f < 1.3. Meeting the above range defines that the optical lens has an appropriate back focal length, facilitating the reasonable arrangement of the positions of each lens and reducing the processing and assembly difficulty. More specifically, 0.99 < BFL / f < 1.15.

[0054] In some embodiments, the clear aperture semi-diameter d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.57 < d1 / (IH / 2) / tan(FOV / 2) < 0.7. Meeting the above range can have a small front aperture while meeting the requirements of the optical lens having a large field of view and a large image plane.

[0055] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: -4.1 < f123 / f4567 < -1.8. Meeting the above range is conducive to balancing various aberrations generated by the lens groups before and after the aperture by reasonably setting the focal length relationship of the lens groups before and after the aperture, and improving the overall imaging quality. More specifically, -3.83 < f123 / f4567 < -1.98.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -1.7. Meeting the above range is conducive to the first lens accommodating a larger angle of light rays and collecting as much light as possible into the rear optical system by setting the first lens to have a negative refractive power, increasing the light flux while achieving a large field of view. More specifically, -2.29 < f1 / f < -1.87.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -9.5 < f2 / f < -7.5. Meeting the above range makes the second lens have a negative optical power, which can share the negative optical power at the front end of the optical lens, thus facilitating the avoidance of excessive light ray deflection caused by the over-concentration of the optical power of the first lens and reducing the difficulty of aberration correction of the optical lens. More specifically, -9.36 < f2 / f < -8.42.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.2 < f5 / f < 2.6; the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: |(R9 + R10) / (R9 - R10)| < 0.2; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 2.4 < R9 / f < 3.3; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -3.3 < R10 / f < -2.2. Meeting the above ranges and setting the fifth lens to have positive refractive power and a suitable surface shape is conducive to converging light while correcting the aberration of the optical lens and improving the imaging quality of the optical lens. More specifically, 2.45 < f5 / f < 2.6; -0.08 < (R9 + R10) / (R9 - R10) < 0.11; 2.65 < R9 / f < 2.99; -3.05 < R10 / f < -2.42.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2 < f6 / f < -1.8; the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 7 < R11 / f < 19; the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.4 < R12 / f < 1.7. Meeting the above ranges can effectively balance various aberrations generated by the front lens group, and at the same time is conducive to increasing the divergence degree of light, increasing the area of light entering the imaging surface, realizing large target surface imaging of the lens, and improving the imaging quality of the optical lens. More specifically, -1.98 < f6 / f < -1.86; 7.32 < R11 / f < 18.09; 1.46 < R12 / f < 1.6.

[0060] 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 < 8; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -33 < R13 / f < -21; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -4 < R14 / f < -3.1. Meeting the above ranges and setting the seventh lens to have positive refractive power and a suitable surface shape is conducive to light convergence, enabling the light trend to smoothly transition to the rear, reducing the height of the light incident on the rear, avoiding light energy loss caused by too large an angle between the main light ray of the large field of view light and the chip when reaching the imaging surface, facilitating the improvement of the illuminance of the edge field of view, and being conducive to achieving a short optical total length. More specifically, 6.61 < f7 / f < 7.88; -30.77 < R13 / f < -22.72; -3.87 < R14 / f < -3.42.

[0061] 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 satisfy: 0.56 < ∑CT / TTL < 0.59. Satisfying the above range can effectively compress the total length of the optical lens, and is conducive to the structural design and production process of the optical lens.

[0062] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 4.45 < ΣCT / f < 5.08. Satisfying the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 6. Satisfying the above range defines that the third lens has an appropriate positive optical power, which has the effect of converging light rays, reducing the height of peripheral light rays, facilitating the reduction of the aperture of the rear lens, and is conducive to balancing aberrations and improving resolution. More specifically, 4.73 < f3 / f < 5.81.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.5 < f4 / f < 3.3; the curvature radius R8 of the image side of the fourth lens and the effective focal length f of the optical lens satisfy: -3.3 < R8 / f < -2.5. Satisfying the above range defines that the fourth lens has an appropriate positive optical power, further converges the light rays, is conducive to making the light rays enter the rear lens smoothly, can adjust the optical path difference between different fields of view, and improve resolution. More specifically, 2.73 < f4 / f < 3.02; -3.1 < R8 / f < -2.77.

[0065] In some embodiments, the optical lens satisfies the following conditional expressions: 3.6 mm < f < 4 mm; 2.1 mm < EPD < 2.4 mm; 30 mm < TTL < 34.3 mm; 1.6 < Fno < 1.8; 20° < CRA < 24°; 3.6 mm < BFL < 4.7 mm; 135° < FOV < 150°; 8 mm < IH < 9.5 mm. 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 overall optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true 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. Meeting the above ranges, the optical lens has at least one or more advantages such as a large field of view angle, a large target surface, and a large aperture. More specifically, 3.86 mm < f < 3.91 mm; 2.28 mm < EPD < 2.36 mm; 30.11 mm < TTL < 34.22 mm; 1.64 < Fno < 1.71; 21.36° < CRA < 23.88°; 3.87 mm < BFL < 4.42 mm; 139° < FOV < 145°; 8.5 mm < IH < 8.92 mm.

[0066] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low-dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0067] 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 spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the fourth lens of the present invention adopts an aspherical lens; the first lens, the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens adopt spherical lenses.

[0068] In various embodiments of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; Among them, z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, and F are the conic coefficients of the fourth, sixth, eighth, tenth, and twelfth orders respectively.

[0069] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, curvature radius, and material selection of each lens in the optical lens are somewhat different. For specific differences, refer to the parameter tables of each embodiment. The following embodiments are only the preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent substitution methods and are included in the protection scope of the present invention.

[0070] Embodiment 1 Please refer to Figure 1 , which shows a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially 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, a filter G1, and a protective glass G2.

[0071] Among them, the first lens L1 has a negative optical power. Its object side S1 is a convex surface, and its image side S2 is a concave surface; The second lens L2 has a negative optical power. Its object side S3 is a concave surface, and its image side S4 is a convex surface; The third lens L3 has a positive optical power. Its object side S5 is a convex surface, and its image side S6 is a concave surface; The fourth lens L4 has a positive optical power. Its object side S7 is a convex surface, and its image side S8 is a convex surface; The fifth lens L5 has a positive optical power. Its object side S9 is a convex surface, and its image side S10 is a convex surface; The sixth lens L6 has a negative optical power. Its object side S11 is a convex surface, and its image side S12 is a concave surface; The seventh lens L7 has a positive optical power. Its object side S13 is a concave surface, and its image side S14 is a convex surface; The object side S15 and the image side S16 of the filter G1 are both flat surfaces; The object side S17 and the image side S18 of the protective glass G2 are both flat surfaces; The imaging surface S19 is a flat surface.

[0072] The fourth lens L4 is a glass aspherical lens; 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.

[0073] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0074] Table 1-1 The surface shape parameters of the aspherical lens of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0075] Table 1-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, axial aberration curve graph, lateral chromatic aberration curve graph, and MTF curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 shown.

[0076] Figure 2 shows the field curvature curve graph of Embodiment 1, which represents the field curvature of light rays with different wavelengths in the meridional image plane and the sagittal image plane. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.03 mm to 0.02 mm, indicating that the optical lens 100 can well correct the field curvature.

[0077] Figure 3 shows the F-Tan(Theta) distortion curve graph of Embodiment 1, which represents the F-Tan(Theta) distortion 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 angle (unit: °). It can be seen from the figure that the F-Tan(Theta) distortion of the optical lens 100 is controlled within -65% to 0, indicating that the distortion of the optical lens 100 is well corrected.

[0078] Figure 4 shows the axial aberration curve graph of Embodiment 1, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within -0.04 mm to 0.06 mm, indicating that the optical lens 100 can better correct the axial aberration.

[0079] Figure 5The vertical chromatic aberration curve graph of Embodiment 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.546 μm) at different image heights on the imaging surface. The horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 100 can excellently correct chromatic aberration.

[0080] Figure 6 The MTF (Modulation Transfer Function) curve graph of Embodiment 1 is shown, which represents the modulation of the lens imaging at different spatial frequencies under each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF values in this embodiment are all above 0.3 within the entire field of view. In the range of 0 - 160 lp / mm, the MTF curve smoothly decreases uniformly from the central field of view to the edge field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0081] Embodiment 2 Please refer to Figure 7 , which shows the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0082] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0083] Table 2-1 The surface type parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0084] Table 2-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, axial aberration curve graph, vertical chromatic aberration curve graph, and MTF curve graph of the optical lens 200 are respectively as shown in Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 .

[0085] From Figure 8 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.03 mm, indicating that the optical lens 200 can well correct the field curvature.

[0086] From Figure 9It can be seen that the F-Tan(Theta) distortion of the optical lens 200 is controlled within -60% to 0, indicating that the distortion of the optical lens 200 is well corrected.

[0087] From Figure 10 it can be seen that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 200 can better correct the axial aberration.

[0088] From Figure 11 it can be seen that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 200 can excellently correct the chromatic aberration.

[0089] From Figure 12 it can be seen that the MTF value of this embodiment is above 0.38 within the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0090] Embodiment 3 Please refer to Figure 13 , which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0091] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0092] Table 3-1 The surface type parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0093] Table 3-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, axial aberration curve graph, lateral chromatic aberration curve graph, and MTF curve graph of the optical lens 300 are respectively as Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 shown.

[0094] From Figure 14 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.03 mm, indicating that the optical lens 300 can well correct the field curvature.

[0095] From Figure 15It can be seen that the F-Tan(Theta) distortion of the optical lens 300 is controlled within -70% to 0, indicating that the distortion of the optical lens 300 is well corrected.

[0096] From Figure 16 it can be seen that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 300 can better correct the axial aberration.

[0097] From Figure 17 it can be seen that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within ±2 μm, indicating that the optical lens 300 can excellently correct the chromatic aberration.

[0098] From Figure 18 it can be seen that the MTF value of this embodiment is above 0.38 within the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0099] Please refer to Table 4 for the optical characteristics corresponding to the above embodiments, including the effective focal length f, the total optical length TTL, the aperture value Fno, the true image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, the chief ray angle of incidence CRA at the maximum image height, and the values corresponding to each conditional formula in each embodiment.

[0100] Table 4 In summary of the above embodiments, the optical lens provided by the present invention uses seven lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, enabling the lens to have one or more advantages such as a large field of view angle, a large target surface, a large aperture, and high imaging quality.

[0101] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean 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 invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0102] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. An optical lens, comprising seven 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 and whose image side is concave; A fourth lens with a positive optical power, whose object side is convex and whose image side is convex; A fifth lens with a positive optical power, whose object side is convex and whose image side is convex; 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 R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 1; 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: 0.6 < (R13 - R14) / (R13 + R14) < 1.

2. The optical lens according to claim 1, characterized in that: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7 < TTL / f < 9; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 4.

2.

3. The optical lens according to claim 1, characterized in that: The maximum field of view angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 80° < FOV / Fno < 90°; the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.6 < IH / EPD < 4.

1.

4. The optical lens according to claim 1, characterized in that: The true 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: 2.15 < IH / f < 2.5; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.9 < BFL / f < 1.

3.

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 of view angle of the optical lens and the maximum field of view angle FOV of the optical lens satisfy: 0.57 < d1 / (IH / 2) / tan(FOV / 2) < 0.7; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -4.1 < f123 / f4567 < -1.

8.

6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -1.7; the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -9.5 < f2 / f < -7.

5.

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: 2.2 < f5 / f < 2.6; the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: |(R9 + R10) / (R9 - R10)| < 0.

2.

8. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2 < f6 / f < -1.8; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 7 < R11 / f < 19; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: 1.4 < R12 / f < 1.

7.

9. 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 < 8; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -33 < R13 / f < -21; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -4 < R14 / f < -3.

1.

10. The optical lens according to claim 1, characterized in that: The object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: 0.66 < (R11 - R12) / (R11 + R12) < 0.85; the object-side curvature radius R13 of the seventh lens and the image-side curvature radius R14 of the seventh lens satisfy: 0.71 < (R13 - R14) / (R13 + R14) < 0.81.

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