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; 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 concave 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 image plane, a large aperture and high imaging quality.

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, on-vehicle application optical lenses are increasingly used in intelligent driving, and the status of on-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 the driver. 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 with the advantage of excellent imaging quality.

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

[0006] An optical lens, comprising a total of seven lenses, which sequentially include from the object side to the imaging surface along the optical axis:

[0007] A first lens with negative optical power, its object side is convex, and its image side is concave;

[0008] A second lens with negative optical power, its object side is concave, and its image side is convex;

[0009] A third lens with positive optical power, its object side is convex;

[0010] A fourth lens with positive optical power, its image side is convex;

[0011] A fifth lens with positive optical power, its object side is convex, and its image side is concave;

[0012] A sixth lens with negative optical power, its object side is convex, and its image side is concave;

[0013] A seventh lens with positive optical power, its object side is concave, and its image side is convex;

[0014] 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.

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

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

[0017] Further 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: 2.1 < 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 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: 0.55 < 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 radius of curvature R9 of the object side of the fifth lens and the effective focal length f of the optical lens satisfy: 1.5 < R9 / f < 2.6; the radius of curvature R10 of the image side 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 radius of curvature R13 of the object side of the seventh lens and the effective focal length f of the optical lens satisfy: -30 < R13 / f < -17; the radius of curvature R14 of the image side of the seventh lens and the effective focal length f of the optical lens satisfy: -9 < R14 / f < -3.

[0022] More preferably, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -0.85 < (R9 - R10) / (R9 + R10) < -0.6; 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: 0.08 < R9 / R10 < 0.22.

[0023] More preferably, the clear aperture semi-diameter d13 of the object side surface of the seventh lens and the sagittal height 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 sagittal height Sag14 of the clear aperture of the image side surface of the seventh lens satisfy: -0.18 < Sag14 / d14 < -0.03.

[0024] The optical lens provided by the present invention uses 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, 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 image plane, a large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0026] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 2 is a F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 is a MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 4 is an axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 6 is a F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 7 is a MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 8It is the axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 9 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 10 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 11 It is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 12 It is the axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 13 It is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0039] Figure 14 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0040] Figure 15 It is the MTF curve graph of the optical lens in Embodiment 4 of the present invention.

[0041] Figure 16 It is the axial aberration curve graph of the optical lens in Embodiment 4 of the present invention.

[0042] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0043] To better understand the present application, more detailed descriptions of various aspects of the present application will be made 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.

[0044] 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 feature and do not represent any limitation on the feature. 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.

[0045] In the drawings, for ease of explanation, the thickness, dimensions, and shape of the lens are slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are presented by way of example. That is, the spherical or aspherical shapes are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn to an exact scale.

[0046] In this document, 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.

[0047] It should also be understood that the terms "comprises," "comprising," "has," "including," and / or "including having," when used in this specification, denote the presence of the stated features, elements, and / or components, but do not preclude 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 a list of listed features, it modifies the entire list of listed features rather than individual elements in the list. Further, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application." Also, the term "exemplary" is intended to refer to an example or illustration.

[0048] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. 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.

[0049] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. 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 an embodiment of the present invention is composed 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.

[0051] 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 convex or concave. The fourth lens may have a positive optical power, with its object side being convex or concave 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 concave. 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.

[0052] In some embodiments, the optical lens may further include a diaphragm, which 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. Additionally, 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. Furthermore, when the diaphragm is located between the third lens and the fourth lens, it is convenient to correct the diaphragm aberration.

[0053] In some embodiments, the optical lens may further include a filter and a protective glass, which are 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 anti-impact and scratch-resistant capabilities of the optical lens, while having little impact on the imaging quality of the optical lens.

[0054] In some embodiments, the radius of curvature R13 of the object side of the seventh lens and the radius of curvature R14 of the image side of the seventh lens satisfy: 0.3 < (R13 - R14) / (R13 + R14) < 0.85. Meeting the above range, by reasonably controlling the shape of the seventh lens, it helps to reduce the light deflection angle, making the light trend reaching the imaging surface stable, and can effectively improve the imaging quality of the optical lens. More specifically, 0.33 < (R13 - R14) / (R13 + R14) < 0.82.

[0055] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.7 < 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: 3.9 < TTL / IH < 4.1. Meeting the above ranges helps to ensure sufficient space for adjusting the structures of the lenses inside the optical lens, optimize the imaging effect, balance the requirements of the image plane size and the overall size of the optical lens, and 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 of view 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 of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.5 < IH / EPD < 3.7. Meeting the above ranges is beneficial to expanding the field of view angle of the optical lens and increasing the aperture of the optical lens, facilitating the optical lens to obtain more scene information and meet the requirements of large-range detection. The realization of the large-aperture characteristic is beneficial to improving the problem of rapid decline of the relative brightness in the edge field of view, thereby also being beneficial to obtaining more scene information, and increasing the width of the light beam entering the optical lens, so that the brightness at the image plane of the optical lens is improved to avoid vignetting and enhance the relative illuminance at the edge of the image plane of the optical lens. More specifically, 88.68° < FOV / Fno < 90.69°, 3.52 < IH / EPD < 3.63.

[0057] 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: 2.1 < 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. Meeting 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 an appropriate back focal length, facilitating the reasonable arrangement of the positions of the lenses, and at the same time 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 clear aperture radius 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: 0.55 < 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. Meeting the above ranges can effectively control the front aperture and the rear aperture 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 helps to balance the lens aberration and improve the imaging quality. More specifically, 2.22 < f4567 / f < 3.52.

[0059] In some embodiments, 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. Meeting the above ranges, by reasonably distributing the negative optical power ratio of the second lens, it helps to share the negative optical power of the front-end lens, avoid excessive light deflection caused by overly concentrated optical power, and reduce the difficulty of chromatic aberration correction of the optical lens; by reasonably distributing the positive optical power ratio of the third lens, it helps to converge the marginal field light and transmit more light to the rear-end lens to correct the aberration and improve the imaging quality. More specifically, -28.09 < f2 / f < -11.93, 3.54 < f3 / f < 7.3.

[0060] In some embodiments, 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 radius of curvature 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 radius of curvature 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. Meeting the above ranges, by reasonably distributing the positive optical power ratio of the fifth lens, it helps to balance the lens aberration and improve the imaging quality, and by defining the shapes of the object side surface and the image side surface of the fifth lens, it helps to optimize the spherical aberration and improve the imaging quality. More specifically, 2.96 < f5 / f < 5.65, 1.56 < R9 / f < 2.59, 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 radius of curvature 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 radius of curvature 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. Meeting the above ranges, by reasonably distributing the proportion of the positive optical power of the seventh lens, it helps to improve the brightness of the edge field of view, avoid vignetting, and by defining the shapes of the object side surface and the image side surface of the seventh lens, it helps to slow down the degree of light deflection and reduce aberration. More specifically, 6.05 < f7 / f < 18.02, -29.33 < R13 / f < -17.12, -8.51 < R14 / f < -3.08.

[0062] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -0.85 < (R9 - R10) / (R9 + R10) < -0.6; 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: 0.08 < R9 / R10 < 0.22. Meeting the above ranges, by reasonably defining the shapes of the object side surface and the image side surface of the fifth lens, it helps to further balance the lens aberration, improve the imaging quality; and reduce the difficulty of aberration correction of the rear-end lens. More specifically, -0.84 < (R9 - R10) / (R9 + R10) < -0.64.

[0063] In some embodiments, the clear aperture semi-diameter d13 of the object side surface of the seventh lens and the sagittal height 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 sagittal height Sag14 of the clear aperture of the image side surface of the seventh lens satisfy: -0.18 < Sag14 / d14 < -0.03. Meeting the above ranges helps to control the trend of light in the edge field of view and highlight the detailed information of the light in the center field of view of the lens.

[0064] In some embodiments, the overall 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: 0.46 < ∑CT / TTL < 0.54; the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 4.1 < ∑CT / f < 4.7. Meeting the above ranges can achieve high pixel characteristics, improve the imaging quality of the optical lens, and reduce the production cost. 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. Meeting the above range and reasonably defining the proportion of the negative optical power of the first lens helps to achieve large-angle light collection and obtain more picture information. 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. Meeting the above range and reasonably defining the proportion of the positive optical power of the fourth lens helps to reduce the field curvature of the optical lens and improve the imaging quality. 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 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 < 20; 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: 1.7 < R12 / f < 2.1. Meeting the above range and reasonably distributing the proportion of the negative optical power of the sixth lens helps to increase the imaging area of the lens and improve the imaging quality. And by defining the shapes of the object side surface and the image side surface of the sixth lens, it helps to reduce the high-order aberration of the optical lens and improve the imaging quality. 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: 4 mm < f < 4.2 mm; 144° < FOV < 150°; 2.5 mm < EPD < 2.6 mm; 36 mm < TTL < 37 mm; 1.6 < Fno < 1.7; 8.9 mm < IH < 9.1 mm; 17° < CRA < 27°; 3.5 mm < BFL < 5.5 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 total 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 image plane, a large aperture, and high imaging quality. More specifically, 4.04 mm < f < 4.19 mm; 2.5 mm < EPD < 2.57 mm; 36.01 mm < TTL < 36.62 mm; 1.6 < Fno < 1.65; 17.38° < CRA < 26.67°; 3.5 mm < BFL < 5.46 mm; 144.9° < FOV < 146.1°; 8.96 mm < IH < 9.1 mm.

[0069] In some embodiments, the lens material of 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. 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.

[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 spherical lenses or aspherical lenses. Compared with the spherical lens structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fifth lens, and the sixth lens of the present invention adopt spherical lenses, 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 invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0072]

[0073] 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.

[0074] The present invention will be further described below with reference to multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are partially different. For specific differences, refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any 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.

[0075] Embodiment 1

[0076] 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, and a filter G1.

[0077] 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;

[0078] 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;

[0079] 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;

[0080] The fourth lens L4 has a positive optical power. Both its object side S7 and image side S8 are convex surfaces;

[0081] The fifth lens L5 has a positive optical power. Its object side S9 is a convex surface, and its image side S10 is a concave surface;

[0082] 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;

[0083] 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;

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

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

[0086] The imaging surface 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 made of glass spherical lenses, and the fourth lens L4 is made of a glass aspherical lens.

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

[0089] Table 1-1

[0090]

[0091]

[0092] The surface profile parameters of the aspherical lens in the optical lens 100 in Embodiment 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 graph, the MTF curve graph, and the axial aberration curve graph of the optical lens 100 are as Figures 2 to 4 shown.

[0096] Figure 2 Shows the F-Tan(Theta) distortion curve of Embodiment 1, which represents the F-Tan(Theta) distortion of light rays with different wavelengths at different image heights on the imaging surface. The horizontal axis represents the F-Tan(Theta) distortion value (unit: %), and the vertical axis represents the half field of view angle (unit: °). It can be seen from the figure that the F-Tan(Theta) distortion of the optical lens is controlled within -70% to 0, indicating that the optical lens can correct distortion well.

[0097] Figure 3 Shows the MTF (Modulation Transfer Function) curve graph of Embodiment 1, which represents the modulation degree of lens imaging at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value in this embodiment is above 0.3 in the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0098] Figure 4The axial aberration curve graph of Embodiment 1 is shown, which represents the aberration on the optical axis at the imaging plane for each wavelength. 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 -0.02 mm to 0.05 mm, indicating that the optical lens 100 can correct the axial aberration well.

[0099] Embodiment 2

[0100] Please refer to Figure 5 , 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.

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

[0102] Table 2-1

[0103]

[0104]

[0105] The surface type parameters of the aspherical lens in the optical lens 200 in 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 this embodiment, the F-Tan(Theta) distortion curve graph, MTF curve graph, and axial aberration curve graph of the optical lens 200 are as Figures 6 to 8 shown.

[0109] From Figure 6 it can be seen that the F-Tan(Theta) distortion of the optical lens is controlled within -70% to 0, indicating that the distortion of the optical lens 200 is corrected well.

[0110] From Figure 7 it can be seen that the MTF value of this embodiment is above 0.35 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0111] From Figure 8 it can be seen that the offset of the axial aberration is controlled within -0.02 mm to 0.06 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0112] Example 3

[0113] Please refer to Figure 9 , 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.

[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 type parameters of the aspherical lenses in 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 graph, MTF curve graph, and axial aberration curve graph of the optical lens 300 are as shown in Figures 10 to 12 shown.

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

[0122] From Figure 11 it can be seen that the MTF value of this embodiment is above 0.35 within the entire field of view. In the range of 0 to 120 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.

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

[0124] Example 4

[0125] Please refer to Figure 13 , which shows the structural schematic diagram of the optical lens 400 provided in Embodiment 4 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.

[0126] The relevant 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 type 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 graph, MTF curve graph, and axial aberration curve graph of the optical lens 400 are as Figures 14 to 16 shown.

[0134] From Figure 14 it can be seen that the F-Tan(Theta) distortion of the optical lens is controlled within -70% to 0, indicating that the distortion of the optical lens 400 is well corrected.

[0135] From Figure 15 it can be seen that the MTF value of this embodiment is above 0.4 within the entire field of view. In the range of 0 to 120 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.

[0136] From Figure 16 it can be seen that the offset of the axial aberration is controlled within -0.04 mm to 0.04 mm, indicating that the optical lens 400 can well correct the axial aberration.

[0137] Please refer to Table 5 for the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view angle, maximum field of view angle FOV, and the values corresponding to each conditional formula in each embodiment.

[0138] Table 5

[0139]

[0140]

[0141] In summary of the above embodiments, 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, and enhance the imaging quality of the optical lens, enabling the lens to have one or more advantages such as a large field of view, a large image plane, a large aperture, and high imaging quality.

[0142] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present 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.

[0143] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of 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 belong to the protection scope of the present invention. Therefore, the protection scope of the patent of 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 negative optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is concave and whose image side is convex; A third lens with positive optical power, whose object side is convex; A fourth lens with positive optical power, whose image side is convex; A fifth lens with positive optical power, whose object side is convex and whose image side is concave; A sixth lens with negative optical power, whose object side is convex and whose image side is concave; A seventh lens with 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.

2. The optical lens according to claim 1, characterized in that: The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.7 < 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: 3.9 < TTL / IH < 4.

1.

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: 88° < FOV / Fno < 91°; 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: 3.5 < 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 of view 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 of view angle of the optical lens, and the maximum field of view 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 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 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 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.

9. The optical lens according to claim 1, characterized in that: The object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: -0.85 < (R9 - R10) / (R9 + R10) < -0.6; the object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: 0.08 < R9 / R10 < 0.

22.

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

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