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 and the image side surface of the fourth lens are convex surfaces; 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 sixth lens has negative focal power, and the image side surface of the sixth lens is a concave surface; the seventh lens has positive focal power; the curvature radius R9 of the object side surface of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens meet the formula:-0.85 lt; (R9-R10) / (R9 + R10) lt; and-0.4. 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, 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 drivers. In addition to requiring the optical lens to have a thin, light, short and small shape and have characteristics such as high pixels and high resolution, 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 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 successively include from the object side to the imaging surface along the optical axis:

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

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

[0009] A third lens with positive optical power, whose object side is convex and whose image side is concave;

[0010] A fourth lens with positive optical power, whose object side and image side are both convex;

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

[0012] A sixth lens with negative optical power, whose image side is concave;

[0013] A seventh lens with positive optical power;

[0014] Wherein, 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: -0.85 < (R9 - R10) / (R9 + R10) < -0.4.

[0015] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.4 < 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 maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 87° < 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: 3.3 < IH / EPD < 3.7.

[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: 0.7 < BFL / f < 1.4.

[0018] Further preferably, the clear aperture 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) < 0.64; 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 < 3.3.

[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 < -24; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.7 < f6 / f < -1.7.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 7.3; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R5 / f < 6.2; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 17 < R6 / f < 440.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.4 < f4 / f < 3.1; the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1.9 < R7 / f < 3.4; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -1.9.

[0022] More preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.5 < f7 / f < 19; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 0.23 < R13 / R14 < 5.4.

[0023] More preferably, the clear aperture radius d9 of the object side surface of the fifth lens and the sagittal height Sag9 of the clear aperture of the object side surface of the fifth lens satisfy: 0.2 < Sag9 / d9 < 0.35; the clear aperture radius d10 of the image side surface of the fifth lens and the sagittal height Sag10 of the clear aperture of the image side surface of the fifth lens satisfy: 0.01 < Sag10 / d10 < 0.09.

[0024] 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

[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 the F-Tan(Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

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

[0029] Figure 4 is the 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 the F-Tan(Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 7 is the 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 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 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, 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.

[0044] It should be noted that in this specification, the expressions such as first, second, and third 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, size, and shape of the lens are 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 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 to be 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, indicate 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 a list of listed features, it modifies the entire list of listed features, rather than an individual element in the list. In addition, when describing 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.

[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 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.

[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 combination with embodiments.

[0050] 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.

[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 concave. The fourth lens may have a positive optical power, with both its object side and 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 either concave or convex and its image side being concave. The seventh lens may have a positive optical power, with its object side being either concave or convex and its image side being either concave or 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 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 shock resistance and scratch resistance of the optical lens, while having almost no impact on the imaging quality of the optical lens.

[0054] In some embodiments, 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: -0.85 < (R9 - R10) / (R9 + R10) < -0.4. Meeting the above range is beneficial for light convergence, enabling the light trend to smoothly transition to the rear, which is beneficial for correcting the aberrations of the entire optical lens and improving the imaging quality of the optical lens; at the same time, it reduces the height of the light incident on the rear, slows down the upward trend of the light, and avoids the light energy loss caused by the excessive main ray angle between the large field-of-view light and the chip when reaching the imaging surface, which is beneficial for improving the illuminance of the edge field of view. More specifically, -0.81 < (R9 - R10) / (R9 + R10) < -0.41.

[0055] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.4 < TTL / f < 9. Meeting the above range can effectively limit the length of the lens and is conducive to the miniaturization of the optical lens. More specifically, 8.42 < TTL / f < 8.97.

[0056] In some embodiments, 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 range ensures that the lens has a larger image plane under the same total length of the lens, can match a larger-sized imaging chip to achieve high-definition imaging, and better realizes the balance between the small total length and the large image plane of the lens. More specifically, 3.98 < TTL / IH < 4.02.

[0057] In some embodiments, the maximum field of view angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 87° < FOV / Fno < 91°. Meeting the above range limits the optical lens to have a suitable field of view angle and f-number, can collect light at a large angle and obtain good imaging quality. More specifically, 87.92° < FOV / Fno < 90.69°.

[0058] 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: 3.3 < IH / EPD < 3.7. Meeting the above range can increase the width of the light beam incident on the optical lens, improve the brightness at the image plane of the optical lens and avoid the generation of vignetting. More specifically, 3.36 < IH / EPD < 3.63.

[0059] 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. 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, 2.1 < IH / f < 2.26.

[0060] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.7 < BFL / f < 1.4. Meeting the above range limits the optical lens to have a suitable back focus, facilitates the reasonable arrangement of the positions of each lens, and at the same time reduces the processing and assembly difficulty. More specifically, 0.73 < BFL / f < 1.31.

[0061] In some embodiments, the clear aperture 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) < 0.64. Meeting the above range can have a small front aperture while meeting the requirements of the optical lens having a large field of view angle and a large image plane.

[0062] In some embodiments, 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 < 3.3. Meeting the above range is beneficial to balancing various aberrations generated by the lens group in front of the aperture by reasonably setting the relationship of the lens group behind the aperture, and improving the overall imaging quality. More specifically, 2.22 < f4567 / f < 3.27.

[0063] 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 < -24; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -2.6 < R3 / f < -1.9; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: -3.6 < R4 / f < -2.8. Meeting the above range enables the second lens to have a negative optical power and a suitable surface shape, which can share the negative optical power at the front end of the optical lens, thereby facilitating avoiding excessive light deflection caused by overly concentrated optical power of the first lens and reducing the difficulty of aberration correction of the optical lens. More specifically, -28.21 < f2 / f < -24.53; -2.59 < R3 / f < -1.99; -3.58 < R4 / f < -2.88.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.7 < f6 / f < -1.7. Meeting the above range can effectively balance various aberrations generated by the front lens group, and at the same time is beneficial to increasing the divergence degree of light, increasing the area of light entering the imaging plane, realizing large target surface imaging of the lens, and improving the imaging quality of the optical lens. More specifically, -2.61 < f6 / f < -1.74.

[0065] 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 < 7.3; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R5 / f < 6.2; the radius of curvature R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 17 < R6 / f < 440. Satisfying the above ranges defines that the third lens has an appropriate positive optical power and a suitable surface shape, has the effect of converging light, reduces the height of peripheral light, is beneficial to reducing the aperture of the rear lens, and is also beneficial to balancing aberrations and improving resolution. More specifically, 4.56 < f3 / f < 7.3; 2.33 < R5 / f < 6.17; 17.99 < R6 / f < 439.93.

[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 < 3.1; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1.9 < R7 / f < 3.4; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -1.9. Satisfying the above ranges defines that the fourth lens has an appropriate positive optical power and a biconvex surface shape, further converges light, is beneficial to making the light enter the rear lens smoothly, can adjust the optical path difference between different fields of view, and improves resolution. More specifically, 2.41 < f4 / f < 3.01; 1.9 < R7 / f < 3.31; -2.59 < R8 / f < -1.93.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.5 < f7 / f < 19; 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: 0.23 < R13 / R14 < 5.4. Satisfying the above ranges sets the seventh lens to have a positive refractive power and a suitable surface shape, which is beneficial to light convergence, makes the light trend transition smoothly to the rear, reduces the height of the light incident on the rear, avoids the light energy loss caused by the excessive main ray angle of the large field of view light reaching the imaging surface, is beneficial to improving the illuminance of the edge field of view, and is also beneficial to achieving a short optical total length. More specifically, 3.52 < f7 / f < 18.02; 0.23 < R13 / R14 < 5.31.

[0068] In some embodiments, the clear aperture semi-diameter d9 of the object side surface of the fifth lens and the sagittal height Sag9 of the clear aperture of the object side surface of the fifth lens satisfy: 0.2 < Sag9 / d9 < 0.35; the clear aperture semi-diameter d10 of the image side surface of the fifth lens and the sagittal height Sag10 of the clear aperture of the image side surface of the fifth lens satisfy: 0.01 < Sag10 / d10 < 0.09. Meeting the above ranges helps to control the trend of light rays in the peripheral field of view and highlight the detailed information of the central field of view of the optical lens.

[0069] 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: 0.46 < ∑CT / TTL < 0.58. Meeting 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.

[0070] 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: 4.1 < ΣCT / f < 4.9. Meeting the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens. More specifically, 4.14 < ΣCT / f < 4.89.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.9. Meeting the above range, by setting the first lens to have a negative refractive power, it is beneficial for the first lens to receive light rays at a larger angle and collect as much light as possible to enter the rear optical system, achieving a large field of view while increasing the light flux. More specifically, -2.29 < f1 / f < -1.95.

[0072] 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 < 6.8; 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: 5.9 < R10 / f < 22. Meeting the above range, setting the fifth lens to have a positive refractive power and a suitable surface shape is beneficial for converging light rays while correcting the aberration of the optical lens and improving the imaging quality of the optical lens. More specifically, 2.96 < f5 / f < 6.76; 1.56 < R9 / f < 2.59; 5.91 < R10 / f < 21.57.

[0073] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -0.98 < (R5 - R6) / (R5 + R6) < -0.7. Meeting the above range is beneficial to balancing the aberration generated by the front lens, facilitating the correction of the aberration of the entire optical lens, and improving the imaging quality of the optical lens.

[0074] In some embodiments, the optical lens satisfies the following conditional expressions: 4 mm < f < 4.3 mm; 140° < FOV < 150°; 2.5 mm < EPD < 2.7 mm; 35 mm < TTL < 37 mm; 1.55 < Fno < 1.65; 8.7 mm < IH < 9.1 mm; 15° < CRA < 27°; 3 mm < BFL < 5.4 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 range, 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, 4.04 mm < f < 4.24 mm; 2.5 mm < EPD < 2.65 mm; 35.03 mm < TTL < 36.27 mm; 1.59 < Fno < 1.64; 15.55° < CRA < 26.67°; 3.05 mm < BFL < 5.31 mm; 141° < FOV < 147°; 8.74 mm < IH < 9.1 mm.

[0075] 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. Additionally, 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.

[0076] 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 fourth lens of the present invention adopts an aspherical lens; the first lens, the second lens, the third lens, the fifth lens, and the sixth lens adopt spherical lenses; the seventh lens can adopt a spherical lens or an aspherical lens.

[0077] In various embodiments of the present invention, when an aspherical lens is used, the shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0078]

[0079] where 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 coefficients of the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surfaces respectively.

[0080] The present invention will be further described in multiple embodiments below. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are partially different. For specific differences, please 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 replacement methods and are included in the protection scope of the present invention.

[0081] Embodiment 1

[0082] Please refer to Figure 1 , which shows a schematic structural diagram of an 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.

[0083] Among them, the first lens L1 has a negative optical power. Its object side surface S1 is a convex surface, and its image side surface S2 is a concave surface;

[0084] The second lens L2 has a negative optical power. Its object side surface S3 is a concave surface, and its image side surface S4 is a convex surface;

[0085] The third lens L3 has a positive optical power. Its object side surface S5 is a convex surface, and its image side surface S6 is a concave surface;

[0086] The fourth lens L4 has a positive optical power. Both its object side surface S7 and its image side surface S8 are convex surfaces;

[0087] The fifth lens L5 has a positive optical power. Its object side surface S9 is a convex surface, and its image side surface S10 is a concave surface;

[0088] The sixth lens L6 has a negative optical power. Its object side surface S11 is a convex surface, and its image side surface S12 is a concave surface;

[0089] The seventh lens L7 has a positive optical power. Its object side surface S13 is a concave surface, and its image side surface S14 is a convex surface;

[0090] Both the object side S15 and the image side S16 of the filter G1 are flat surfaces.

[0091] Both the object side S17 and the image side S18 of the protective glass G2 are flat surfaces.

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

[0093] 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.

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

[0095] Table 1-1

[0096]

[0097]

[0098] The surface type parameters of the aspherical lens of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0099] Table 1-2

[0100] 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

[0101] In this embodiment, the F-Tan(Theta) distortion curve, the MTF curve graph, and the axial aberration curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 shown.

[0102] 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 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, and the image compression in the edge angle region is relatively gentle, effectively improving the clarity of the expanded image.

[0103] Figure 3The MTF (Modulation Transfer Function) curve graph of Embodiment 1 is shown, which represents the modulation of lens imaging at different spatial frequencies for 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 of this embodiment is above 0.35 within the entire field of view. In the range of 0 - 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.

[0104] Figure 4 The 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 can correct the axial aberration well.

[0105] Embodiment 2

[0106] 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 differences are: the object side S13 of the seventh lens L7 is a convex surface; the image side S14 of the seventh lens L7 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

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

[0108] Table 2-1

[0109]

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

[0111] Table 2-2

[0112]

[0113]

[0114] In this embodiment, the F-Tan(Theta) distortion curve, MTF curve graph, and axial aberration curve graph of the optical lens 200 are respectively as Figure 6 , Figure 7 , Figure 8 shown.

[0115] From Figure 6It can be seen that the F-Tan(Theta) distortion of the optical lens is controlled within -70% to 0, and the image compression in the edge angle region is relatively gentle, effectively improving the clarity of the unfolded image.

[0116] From Figure 7 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 it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0117] From Figure 8 it can be seen that the offset of the axial aberration is controlled within -0.02 mm to 0.05 mm, indicating that the optical lens can better correct the axial aberration.

[0118] Embodiment 3

[0119] 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 differences are: the object side S11 of the sixth lens L6 is a concave surface; the object side S13 of the seventh lens L7 is a convex surface; the image side S14 of the seventh lens L7 is a concave surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0120] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123]

[0124] The surface type parameters of the aspherical lenses in the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0125] Table 3-2

[0126] Surface number K B C D E F S7 -1.78E+01 -3.45E-04 1.09E-04 -3.59E-05 3.56E-06 -1.36E-07 S8 1.71E+00 2.17E-04 2.72E-06 -1.03E-06 7.84E-08 -2.12E-09

[0127] In this embodiment, the F-Tan(Theta) distortion curve, MTF curve graph, and axial aberration curve graph of the optical lens 300 are respectively as shown in Figure 10 , Figure 11 , Figure 12 shown.

[0128] From Figure 10 it can be seen that the F-Tan(Theta) distortion of the optical lens is controlled within -65% to 0, indicating that the optical lens can better correct the distortion.

[0129] It can be seen from Figure 11 that the MTF value of this embodiment is above 0.35 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases uniformly and smoothly 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.

[0130] It can be seen from Figure 12 that the offset of the axial aberration is controlled within -0.02 mm to 0.05 mm, indicating that the optical lens can correct the axial aberration well.

[0131] Embodiment 4

[0132] Please refer to Figure 13 , which shows a schematic structural diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main difference is that the seventh lens adopts a glass aspherical lens; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0133] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4.

[0134] Table 4-1

[0135]

[0136]

[0137] The surface type parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0138] Table 4-2

[0139] 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

[0140] In this embodiment, the F-Tan(Theta) distortion curve, MTF curve graph, and axial aberration curve graph of the optical lens 400 are respectively as Figure 14 , Figure 15 , Figure 16 shown.

[0141] It can be seen from Figure 14 that the F-Tan(Theta) distortion of the optical lens is controlled within -65% to 0, and the image compression in the edge angle region is relatively gentle, effectively improving the clarity of the unfolded image.

[0142] It can be seen from Figure 15It can be seen that the MTF value of this embodiment is above 0.4 throughout 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.

[0143] It can be seen from Figure 16 that the offset of the axial aberration is controlled within -0.03 mm to 0.03 mm, indicating that the optical lens can correct the axial aberration well.

[0144] Please refer to Table 5 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, 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, and the values corresponding to each conditional expression in each embodiment.

[0145] Table 5

[0146]

[0147]

[0148] Combining 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 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.

[0149] In the description of this specification, the description with reference 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 any one or more embodiments or examples in a suitable manner.

[0150] The above-described embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting 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 should be subject to the appended claims.

Claims

1. An optical lens, comprising seven lenses, characterized in that: 依次沿光轴从物侧到成像面包括: A first lens with negative optical power, having a convex object side and a concave image side; A second lens with negative optical power, having a concave object side and a convex image side; A third lens with positive optical power, having a convex object side and a concave image side; A fourth lens with positive optical power, having both a convex object side and a convex image side; A fifth lens with positive optical power, having a convex object side and a concave image side; A sixth lens with negative optical power, having a concave image side; A seventh lens with positive optical power; Wherein, 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: -0.85 < (R9 - R10) / (R9 + R10) < -0.

4.

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: 8.4 < 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: 87° < 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: 3.3 < 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: 0.7 < BFL / f < 1.

4.

5. The optical lens according to claim 1, characterized in that: The clear aperture 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) < 0.64; 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.

3.

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 < -24; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.7 < f6 / f < -1.

7.

7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 7.3; the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R5 / f < 6.2; the radius of curvature R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 17 < R6 / f < 440.

8. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.4 < f4 / f < 3.1; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.9 < R7 / f < 3.4; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -1.

9.

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: 3.5 < f7 / f < 19; the object-side curvature radius R13 of the seventh lens and the image-side curvature radius R14 of the seventh lens satisfy: 0.23 < R13 / R14 < 5.

4.

10. The optical lens according to claim 1, characterized in that: The object-side clear aperture semi-diameter d9 of the fifth lens and the object-side clear aperture sagittal height Sag9 of the fifth lens satisfy: 0.2 < Sag9 / d9 < 0.35; the image-side clear aperture semi-diameter d10 of the fifth lens and the image-side clear aperture sagittal height Sag10 of the fifth lens satisfy: 0.01 < Sag10 / d10 < 0.09.

Images