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 concave surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a convex surface; the object side surface of the sixth lens is a concave 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 convex surface. The optical lens provided by the invention has one or more advantages of large target surface, large aperture, ultra-wide angle and the like.

Description

Technical Field

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

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

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

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens 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 sequentially include, along the optical axis from the object side to the imaging surface:

[0007] A first lens with negative optical power, the object side surface of which is convex and the image side surface of which is concave;

[0008] A second lens with negative optical power, the object side surface of which is concave and the image side surface of which is convex;

[0009] A third lens with positive optical power, the object side surface of which is concave and the image side surface of which is convex;

[0010] A fourth lens with negative optical power, the object side surface of which is concave and the image side surface of which is convex;

[0011] A fifth lens with positive optical power, the object side surface of which is convex and the image side surface of which is convex;

[0012] A sixth lens with negative optical power, the object side surface of which is concave and the image side surface of which is concave;

[0013] A seventh lens with positive optical power, the object side surface of which is convex;

[0014] Wherein, the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.7 < (R5 - R6) / (R5 + R6) < 1.

[0015] More preferably, the true image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.4 < (IH / 2) / (f×Tan(FOV / 2)) < 0.55; the combined focal length f4567 of the fourth lens, fifth lens, sixth lens, and seventh lens and the effective focal length f of the optical lens satisfy: 2 < f4567 / f < 18.

[0016] More preferably, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 72° < FOV / Fno < 81°; 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: 3.9 < IH / EPD < 4.4.

[0017] More preferably, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < IH / f < 2.4; the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1.2 < BFL / f < 1.5.

[0018] More preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -141 < f2 / f < -11; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -3.3 < R3 / f < -2.2; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: -5.1 < R4 / f < -2.7.

[0019] More preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1.8 < f3 / f < 6.5; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -87 < R5 / f < -9; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: -6 < R6 / f < -1.

[0020] More preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -181 < f4 / f < -9.5; the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -4.8 < R7 / f < -0.75; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -10 < R8 / f < -0.8.

[0021] More preferably, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -0.3 < (R3 - R4) / (R3 + R4) < -0.1; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: -0.5 < (R7 - R8) / (R7 + R8) < 0.

[0022] More preferably, the sagittal height Sag4 of the image side light-passing semi-aperture of the second lens and the image side light-passing semi-aperture d4 of the second lens satisfy: -0.23 < Sag4 / d4 < -0.09; the sagittal height Sag5 of the object side light-passing semi-aperture of the third lens and the object side light-passing semi-aperture d5 of the third lens satisfy: -0.14 < Sag5 / d5 < 0.

[0023] More preferably, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R4 of the image side surface of the second lens and the central thickness CT2 of the second lens satisfy: 0.3 < (R3 + CT2) / R4 < 0.5; the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R6 of the image side surface of the third lens and the central thickness CT3 of the third lens satisfy: 7 < (R5 + CT3) / R6 < 23.

[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 target surface, a large aperture, and an ultra-wide angle. 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, wherein:

[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 a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 5 is a F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 6 It is the MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 7 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 8 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 9 It is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 10 It is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 11 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 12 It is the MTF curve graph of the optical lens in Embodiment 4 of the present invention.

[0038] Figure 13 It is the structural schematic diagram of the optical lens in Embodiment 5 of the present invention.

[0039] Figure 14 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 5 of the present invention.

[0040] Figure 15 It is the MTF curve graph of the optical lens in Embodiment 5 of the present invention.

[0041] Figure 16 It is the structural schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0042] Figure 17 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 6 of the present invention.

[0043] Figure 18 It is the MTF curve graph of the optical lens in Embodiment 6 of the present invention.

[0044] Figure 19 It is the structural schematic diagram of the optical lens in Embodiment 7 of the present invention.

[0045] Figure 20 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 7 of the present invention.

[0046] Figure 21It is the MTF curve graph of the optical lens in Embodiment 7 of the present invention.

[0047] Figure 22 It is the structural schematic diagram of the optical lens in Embodiment 8 of the present invention.

[0048] Figure 23 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 8 of the present invention.

[0049] Figure 24 It is the MTF curve graph of the optical lens in Embodiment 8 of the present invention.

[0050] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0051] 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.

[0052] 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 features. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0053] In the drawings, for the sake of clarity, the thickness, dimensions, and shape of the lenses have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are for illustrative purposes only and are not drawn to an exact scale.

[0054] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object 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.

[0055] It should also be understood that the terms "comprising", "comprises", "having", "including" and / or "includes", 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 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". Also, the term "exemplary" is intended to refer to an example or illustration.

[0056] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0057] 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.

[0058] The optical lens provided by the embodiment of the present invention includes 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.

[0059] In some embodiments, the first lens may have a negative optical power, its object side may be convex, and its image side may be concave. The second lens may have a negative optical power, its object side may be concave, and its image side may be convex. The third lens may have a positive optical power, its object side may be concave, and its image side may be convex. The fourth lens may have a negative optical power, its object side may be concave, and its image side may be convex. The fifth lens may have a positive optical power, its object side may be convex, and its image side may be convex. The sixth lens may have a negative optical power, its object side may be concave, and its image side may be concave. The seventh lens may have a positive optical power, its object side may be convex, and its image side may be concave or convex.

[0060] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. When the diaphragm is located between the third lens and the fourth lens, it is convenient for correcting the diaphragm aberration.

[0061] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially disposed between the seventh lens and the imaging surface along the optical axis. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the impact resistance and scratch resistance of the optical lens, while having almost no impact on the imaging quality of the optical lens.

[0062] In some embodiments, the fifth lens and the sixth lens may be glued together to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the decentration sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0063] 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: 0.7 < (R5 - R6) / (R5 + R6) < 1. Meeting the above range reduces the correction difficulty of the subsequent lens spherical aberration and chromatic aberration; at the same time, it is beneficial to the smooth trend of light, and as much as possible of the marginal field beam is transmitted to the rear end of the optical lens, improving the relative illumination of the optical lens. More specifically: 0.75 < (R5 - R6) / (R5 + R6) < 0.93.

[0064] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens, the effective focal length f of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.4 < (IH / 2) / (f × Tan(FOV / 2)) < 0.55; 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 < f4567 / f < 18. Meeting the above range can control the optical lens to have small distortion and improve the imaging quality of the optical lens. At the same time, the rear lens group has an appropriate positive optical power, which can effectively transmit more light beams to the imaging surface, further improving the imaging quality. More specifically: 0.42 < (IH / 2) / (f × Tan(FOV / 2)) < 0.53; 2.03 < f4567 / f < 17.7.

[0065] In some embodiments, the maximum field of view (FOV) of the optical lens and the aperture value (Fno) of the optical lens satisfy: 72° < FOV / Fno < 81°; the true image height (IH) corresponding to the maximum field of view of the optical lens and the entrance pupil diameter (EPD) of the optical lens satisfy: 3.9 < IH / EPD < 4.4. By satisfying the above ranges and reasonably limiting the ratio of the field of view to the aperture value, a large angle of light can be collected and good imaging quality can be obtained. At the same time, reasonably limiting the ratio of the image height to the entrance pupil diameter is beneficial to increasing the light throughput, making the peripheral field of view and the central field of view brighter and more uniform. More specifically: 72.96° < FOV / Fno < 80.01°; 3.95 < IH / EPD < 4.4.

[0066] In some embodiments, the true image height (IH) corresponding to the maximum field of view of the optical lens and the effective focal length (f) of the optical lens satisfy: 2.3 < IH / f < 2.4; the back focal length (BFL) of the optical lens and the effective focal length (f) of the optical lens satisfy: 1.2 < BFL / f < 1.5. By satisfying the above ranges and reasonably controlling the ratio of the image height to the focal length of the optical lens within a reasonable range, it helps the optical lens to have the characteristic of a large image plane. At the same time, limiting the optical lens to have an appropriate back focal length facilitates the reasonable arrangement of the positions of each lens and reduces the processing and assembly difficulty. More specifically: 2.3 < IH / f < 2.39; 1.23 < BFL / f < 1.47.

[0067] In some embodiments, the focal length (f2) of the second lens and the effective focal length (f) of the optical lens satisfy: -141 < f2 / f < -11; the curvature radius (R3) of the object side surface of the second lens and the effective focal length (f) of the optical lens satisfy: -3.3 < R3 / f < -2.2; the curvature radius (R4) of the image side surface of the second lens and the effective focal length (f) of the optical lens satisfy: -5.1 < R4 / f < -2.7. By satisfying the above ranges and reasonably limiting the light power ratio and surface type of the second lens, it is beneficial to achieve a larger light throughput and increase the relative illumination. More specifically: -140.3 < f2 / f < -11.7; -3.2 < R3 / f < -2.23; -5.04 < R4 / f < -2.76.

[0068] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1.8 < f3 / f < 6.5; 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: -87 < R5 / f < -9; 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: -6 < R6 / f < -1. Meeting the above ranges, by reasonably limiting the proportion of the optical power of the third lens and its surface shape, the aberration generated at the front end of the lens can be effectively corrected, and the imaging quality of the lens can be improved. More specifically: 1.8 < f3 / f < 6.31; -86.75 < R5 / f < -9.94; -5.84 < R6 / f < -1.07.

[0069] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -181 < f4 / f < -9.5; 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: -4.8 < R7 / f < -0.75; 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: -10 < R8 / f < -0.8. Meeting the above ranges, by reasonably limiting the proportion of the optical power of the fourth lens and its surface shape, it helps to increase the imaging area and improve the imaging quality. More specifically: -180.2 < f4 / f < -9.67; -4.74 < R7 / f < -0.79; -9.95 < R8 / f < -0.84.

[0070] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: -0.3 < (R3 - R4) / (R3 + R4) < -0.1; the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: -0.5 < (R7 - R8) / (R7 + R8) < 0. Meeting the above ranges, controlling the second lens and the fourth lens to have appropriate surface shapes can effectively correct the aberration of the optical lens. More specifically: -0.27 < (R3 - R4) / (R3 + R4) < -0.1; -0.45 < (R7 - R8) / (R7 + R8) < -0.02.

[0071] In some embodiments, the sagittal height Sag4 of the image side clear aperture of the second lens and the image side clear aperture d4 of the second lens satisfy: -0.23 < Sag4 / d4 < -0.09; the sagittal height Sag5 of the object side clear aperture of the third lens and the object side clear aperture d5 of the third lens satisfy: -0.14 < Sag5 / d5 < 0. Meeting the above ranges helps to control the light ray trend and highlight the detail information of the central field of view of the optical lens.

[0072] In some embodiments, the radius of curvature R3 of the object side surface of the second lens, the radius of curvature R4 of the image side surface of the second lens, and the central thickness CT2 of the second lens satisfy: 0.3 < (R3 + CT2) / R4 < 0.5; the radius of curvature R5 of the object side surface of the third lens, the radius of curvature R6 of the image side surface of the third lens, and the central thickness CT3 of the third lens satisfy: 7 < (R5 + CT3) / R6 < 23. Meeting the above ranges, the radius of curvature and the central thickness jointly affect the shape of the lens, controlling the shapes of the second lens and the third lens within a reasonable range can reduce the difficulty of correcting the marginal field distortion, control the distortion within a reasonable range, and facilitate improving the yield of manufacturing the lens. More specifically: 0.31 < (R3 + CT2) / R4 < 0.47; 7.37 < (R5 + CT3) / R6 < 22.71.

[0073] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 7.2 < TTL / f < 8.3. Meeting the above range is beneficial to limiting the overall length of the lens and achieving miniaturization. More specifically: 7.21 < TTL / f < 8.23.

[0074] In some embodiments, the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 3.5. Meeting the above range ensures that when the lens is used for wide-angle shooting, the overall length is still within a reasonable range. More specifically: 3.07 < TTL / IH < 3.47.

[0075] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis and the overall optical length TTL of the optical lens satisfy: 0.45 < ΣCT / TTL < 0.65. Meeting the above range, controlling the overall optical length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range helps to achieve high pixel characteristics and improve the imaging quality of the optical lens. More specifically: 0.48 < ΣCT / TTL < 0.6.

[0076] In some embodiments, the sum ΣCT 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: 3.5 < ΣCT / f < 5. Meeting the above range, controlling the effective focal length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range makes the lens more compact. More specifically: 3.54 < ΣCT / f < 4.9.

[0077] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -2.5 < f1 / f < -1.9. Meeting the above range defines that the first lens has an appropriate negative optical power and has a diverging effect on the light passing through it, which is beneficial to achieving a small front aperture. More specifically: -2.44 < f1 / f < -1.94.

[0078] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < f5 / f < 2.1. Meeting the above range defines that the fifth lens has an appropriate positive optical power, which is beneficial to light convergence. And by combining the fifth lens with a positive optical power and the sixth lens with a negative optical power, the optical path difference between different fields of view can be adjusted, the resolution can be improved, it is beneficial for the light to enter the rear lens smoothly, further reduce the field curvature, and correct the off-axis aberration of the optical lens. More specifically: 1.02 < f5 / f < 2.01.

[0079] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.5 < f6 / f < -0.9. Meeting the above range defines that the sixth lens has an appropriate negative optical power, which can diverge the light emitted by the fifth lens, making the light in the marginal field of view show an upward trend, which is beneficial for the image point on the imaging surface to be away from the optical axis, so as to achieve the effect of matching with a large chip and obtain a larger picture. More specifically: -1.48 < f6 / f < -0.94.

[0080] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 2 < f7 / f < 3.9. Meeting the above range defines that the seventh lens has an appropriate positive optical power, 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, slows down the upward trend of the light, is beneficial to improving the illuminance of the marginal field of view, and achieves a short optical total length. More specifically: 2.03 < f7 / f < 3.81.

[0081] In some embodiments, the optical lens satisfies the following conditional expressions: 3.8 mm < f < 4.1 mm; 132° < FOV < 140°; 2 mm < EPD < 2.4 mm; 28 mm < TTL < 33 mm; 1.65 < Fno < 1.9; 9 mm < IH < 9.5 mm; 16° < CRA < 25°; 4.5 mm < BFL < 6 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 principal ray incident angle at the maximum image height 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 target surface, a large aperture, and an ultra-wide angle. More specifically: 3.88 mm < f < 4.01 mm; 132.9° < FOV < 139.1°; 2.1 mm < EPD < 2.35 mm; 28.4 mm < TTL < 32.1 mm; 1.69 < Fno < 1.86; 9.24 mm < IH < 9.26 mm; 16.09° < CRA < 24.01°; 4.81 mm < BFL < 5.81 mm.

[0082] 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. Additionally, when the lens material is glass, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. 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.

[0083] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the fourth lens and the seventh lens of the present invention adopt aspherical lenses, the first lens, the second lens, the fifth lens, and the sixth lens adopt spherical lenses, and the third lens adopts an aspherical lens or a spherical lens.

[0084] 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:

[0085]

[0086] Among them, z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, and F are the conic coefficients of the fourth, sixth, eighth, tenth, and twelfth orders of the curved surface respectively.

[0087] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, curvature radius, and material selection of each lens in the optical lens are partially different. For specific differences, please refer to the parameter table 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.

[0088] Embodiment 1

[0089] 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.

[0090] 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;

[0091] 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;

[0092] The third lens L3 has a positive optical power. Its object side surface S5 is a concave surface, and its image side surface S6 is a convex surface;

[0093] The fourth lens L4 has a negative optical power. Its object side surface S7 is a concave surface, and its image side surface S8 is a convex surface;

[0094] 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 convex surface;

[0095] The sixth lens L6 has a negative optical power. Its object side surface S10 is a concave surface, and its image side surface S11 is a concave surface;

[0096] The fifth lens L5 and the sixth lens L6 form a cemented lens group, that is, the cemented surface of the image side surface of the fifth lens L5 and the object side surface of the sixth lens L6 is S10;

[0097] The seventh lens L7 has a positive optical power. Its object side surface S12 is a convex surface, and its image side surface S13 is a concave surface;

[0098] The object side S14 and the image side S15 of the filter G1 are both flat surfaces;

[0099] The object side S16 and the image side S17 of the protective glass G2 are both flat surfaces;

[0100] The imaging surface S18 is a flat surface.

[0101] The third lens L3, the fourth lens L4, and the seventh lens L7 are made of glass aspherical lenses, and the first lens L1, the second lens L2, the fifth lens L5, and the sixth lens L6 are made of glass spherical lenses.

[0102] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0103] Table 1-1

[0104]

[0105] The surface shape parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0106] Table 1-2

[0107]

[0108]

[0109] In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 shown.

[0110] Figure 2 shows the F-Tan(Theta) distortion curve graph of Embodiment 1, which represents the distortion of light rays with different wavelengths at different image heights on the imaging surface. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within -50% to 0%, indicating that the optical lens 100 can correct the distortion well.

[0111] Figure 3 shows the MTF (Modulation Transfer Function) curve graph of Embodiment 1, which represents the modulation of the 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 of this embodiment is above 0.2 within the entire field of view. In the range of 0 to 300 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.

[0112] Embodiment 2

[0113] Please refer to Figure 4 , 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.

[0114] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0115] Table 2-1

[0116]

[0117]

[0118] The aspheric lens surface type parameters of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0119] Table 2-2

[0120] Face number K B C D E F S5 -8.07E+01 -8.54E-04 8.69E-06 3.19E-07 5.65E-08 -1.64E-09 S6 -5.78E+00 -4.21E-04 -2.32E-05 1.13E-05 -8.22E-07 2.97E-08 S7 -1.71E+02 -4.05E-04 9.06E-07 -1.82E-05 2.46E-06 -1.31E-07 S8 1.26E+02 -4.35E-03 2.01E-04 -1.67E-05 1.18E-06 -5.29E-08 S12 -1.97E-01 -1.30E-03 4.21E-05 2.88E-06 1.29E-07 -1.65E-09 S13 5.78E+00 1.33E-04 1.07E-05 8.84E-06 -2.98E-07 2.27E-08

[0121] In this embodiment, the F-Tan(Theta) distortion curve graph and MTF curve graph of the optical lens 200 are respectively as Figure 5 , Figure 6 shown. It can be seen from Figure 5 that the distortion of the optical lens 200 is controlled within -55% to 0%, indicating that the optical lens 200 can correct the distortion well. It can be seen from Figure 6 that the MTF value of this embodiment is above 0.2 within the entire field of view. In the range of 0 to 300 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.

[0122] Embodiment 3

[0123] Please refer to Figure 7 , 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.

[0124] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0125] Table 3-1

[0126]

[0127]

[0128] The surface shape parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0129] Table 3-2

[0130] Face number K B C D E F S5 6.27E+01 -9.92E-04 3.64E-07 3.91E-07 3.91E-08 -5.87E-10 S6 -4.65E+00 -9.17E-04 2.58E-05 2.21E-06 -1.67E-07 5.58E-09 S7 -1.99E+02 6.27E-04 -8.56E-05 -2.81E-06 7.93E-07 -4.61E-08 S8 4.80E+01 -2.22E-03 1.36E-05 4.96E-06 -3.14E-07 3.53E-09 S12 -4.21E-01 -1.96E-03 5.00E-05 -1.23E-06 4.63E-07 -7.64E-09 S13 1.80E+01 -7.59E-04 -1.33E-05 5.95E-06 -1.53E-07 1.74E-08

[0131] In this embodiment, the F-Tan(Theta) distortion curve graph and MTF curve graph of the optical lens 300 are respectively as shown in Figure 8 and Figure 9 shown. It can be seen from Figure 8 that the distortion of the optical lens is controlled within -60% to 0%, indicating that the optical lens 300 can correct the distortion well. It can be seen from Figure 9 that the MTF value of this embodiment is above 0.2 within the entire field of view. In the range of 0 to 300 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.

[0132] Embodiment 4

[0133] Please refer to Figure 10 , which shows the structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0134] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0135] Table 4-1

[0136]

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

[0138] Table 4-2

[0139] Face number K B C D E F S5 -2.00E+02 -1.54E-03 -1.49E-05 4.02E-07 1.83E-07 -5.11E-09 S6 -5.83E+00 -1.48E-03 4.62E-05 6.04E-06 -5.50E-07 2.19E-08 S7 -1.05E+02 1.14E-03 -3.95E-05 -6.48E-06 2.42E-06 -9.39E-08 S8 8.11E+01 -2.59E-03 5.51E-05 1.17E-05 -8.24E-07 7.05E-08 S12 -5.35E+00 -2.38E-06 1.34E-05 -1.41E-06 6.34E-07 -1.40E-08 S13 -5.50E+01 8.78E-04 -3.73E-05 8.02E-06 -1.19E-07 1.88E-08

[0140] In this embodiment, the F-Tan(Theta) distortion curve graph and MTF curve graph of the optical lens 400 are respectively as shown in Figure 11 and Figure 12 shown. It can be seen from Figure 11 that the distortion of the optical lens 400 is controlled within -55% to 0%, indicating that the optical lens 400 can correct the distortion well. It can be seen from Figure 12It can be seen that the MTF value of this embodiment is above 0.1 within the entire field of view. In the range of 0 to 300 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.

[0141] Embodiment 5

[0142] Please refer to Figure 13 , which shows the structural schematic diagram of the optical lens 500 provided in Embodiment 5 of the present invention. Compared with Embodiment 1, the main differences are: the image side S13 of the seventh lens L7 is a convex surface; the third lens L3 uses a glass spherical lens; the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0143] The relevant parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0144] Table 5-1

[0145]

[0146] The aspheric lens surface type parameters of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0147] Table 5-2

[0148]

[0149]

[0150] In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 500 are respectively as shown in Figure 14 , Figure 15 shown. It can be seen from Figure 14 that the distortion of the optical lens 500 is controlled within -55% to 0%, indicating that the optical lens 500 can correct distortion well. It can be seen from Figure 15 that the MTF value of this embodiment is above 0.3 within the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0151] Embodiment 6

[0152] Please refer to Figure 16, which shows the structural schematic diagram of the optical lens 600 provided in Embodiment 6 of the present invention. Compared with Embodiment 1, the main differences are as follows: the image side S13 of the seventh lens L7 is a convex surface; the third lens L3 is a glass spherical lens; and the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0153] The relevant parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0154] Table 6-1

[0155]

[0156]

[0157] The surface type parameters of the aspherical lenses in the optical lens 600 in Embodiment 6 are shown in Table 6-2.

[0158] Table 6-2

[0159] Face number K B C D E F S7 -5.07E-01 5.32E-03 3.23E-04 -1.04E-05 8.97E-07 -8.65E-08 S8 -2.15E+00 3.72E-04 3.24E-04 -4.17E-06 8.60E-08 -2.73E-08 S12 -6.90E-01 1.15E-03 -1.03E-04 8.96E-06 -3.69E-07 6.11E-09 S13 3.03E-01 1.04E-03 -1.41E-05 6.09E-06 -3.72E-07 1.33E-08

[0160] In this embodiment, the F-Tan(Theta) distortion curve graph and MTF curve graph of the optical lens 600 are respectively as Figure 17 , Figure 18 shown. It can be seen from Figure 17 that the distortion of the optical lens 600 is controlled within -60% to 0%, indicating that the optical lens 600 can correct the distortion well. It can be seen from Figure 18 that the MTF value of this embodiment is above 0.3 within the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0161] Embodiment 7

[0162] Please refer to Figure 19 , which shows the structural schematic diagram of the optical lens 700 provided in Embodiment 7 of the present invention. Compared with Embodiment 1, the main differences are as follows: the image side S13 of the seventh lens L7 is a convex surface; the third lens L3 is a glass spherical lens; and the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0163] The relevant parameters of each lens in the optical lens 700 in Embodiment 7 are shown in Table 7-1.

[0164] Table 7-1

[0165]

[0166]

[0167] The surface shape parameters of the aspherical lens of the optical lens 700 in Example 7 are shown in Table 7-2.

[0168] Table 7-2

[0169] Face number K B C D E F S7 -7.13E-03 5.63E-03 1.95E-04 -6.96E-06 1.06E-06 -5.06E-08 S8 -2.83E+00 4.52E-04 1.95E-04 -6.61E-06 3.91E-07 -2.18E-08 S12 -2.62E-01 7.41E-04 -7.41E-05 6.23E-06 -2.38E-07 3.63E-09 S13 -1.24E+00 7.01E-04 -1.83E-05 6.20E-06 -3.71E-07 1.26E-08

[0170] In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 700 are respectively as Figure 20 , Figure 21 shown. It can be seen from Figure 20 that the distortion of the optical lens 700 is controlled within -60% to 0%, indicating that the optical lens 700 can correct distortion well. It can be seen from Figure 21 that the MTF value of this embodiment is above 0.3 within the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0171] Example 8

[0172] Please refer to Figure 22 , which shows the structural schematic diagram of the optical lens 800 provided in Embodiment 8 of the present invention. Compared with Embodiment 1, the main differences are: the image side surface S13 of the seventh lens L7 is a convex surface; the third lens L3 uses a glass spherical lens; the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0173] The relevant parameters of each lens in the optical lens 800 in Example 8 are shown in Table 8-1.

[0174] Table 8-1

[0175]

[0176]

[0177] The surface shape parameters of the aspherical lens of the optical lens 800 in Example 8 are shown in Table 8-2.

[0178] Table 8-2

[0179] Face number K B C D E F S7 -5.31E-01 7.11E-03 2.32E-04 3.77E-05 -7.42E-06 3.58E-07 S8 -2.99E+00 -5.76E-04 5.40E-04 5.56E-06 -3.57E-06 1.76E-07 S12 -1.14E+00 1.36E-03 -1.02E-04 1.17E-05 -5.85E-07 1.12E-08 S13 -4.23E-01 9.65E-04 -1.94E-05 8.54E-06 -5.69E-07 2.24E-08

[0180] In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 800 are respectively as Figure 23 , Figure 24 shown. It can be seen from Figure 23It can be seen that the distortion of the optical lens 800 is controlled within -55% to 0%, indicating that the optical lens 800 can correct distortion well.

[0181] It can be seen from Figure 24 that the MTF value of this embodiment is above 0.3 within the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0182] Please refer to Table 9 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 chief ray angle of incidence CRA at the maximum image height, the true image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, the entrance pupil diameter EPD, the back focal length BFL, and the values corresponding to each conditional formula in each embodiment.

[0183] Table 9

[0184]

[0185]

[0186]

[0187] Combining the above embodiments, 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 target surface, a large aperture, and an ultra-wide angle.

[0188] 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.

[0189] The above-described embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but 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: It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is concave and whose image side is convex; A third lens with a positive optical power, whose object side is concave and whose image side is convex; A fourth lens with a negative optical power, whose object side is concave and whose image side is convex; A fifth lens with a positive optical power, whose object side is convex and whose image side is convex; A sixth lens with a negative optical power, whose object side is concave and whose image side is concave; A seventh lens with a positive optical power, whose object side is convex; Wherein, the radius of curvature R5 of the object side of the third lens and the radius of curvature R6 of the image side of the third lens satisfy: 0.7 < (R5 - R6) / (R5 + R6) < 1.

2. 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, the effective focal length f of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.4 < (IH / 2) / (f × Tan(FOV / 2)) < 0.55; 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 < f4567 / f < 18.

3. The optical lens according to claim 1, characterized in that: The maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 72° < FOV / Fno < 81°; 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: 3.9 < IH / EPD < 4.

4.

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: 2.3 < IH / f < 2.4; The back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 1.2 < BFL / f < 1.

5.

5. The optical lens according to claim 1, characterized in that: The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -141 < f2 / f < -11; The radius of curvature R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: -3.3 < R3 / f < -2.2; The radius of curvature R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: -5.1 < R4 / f < -2.

7.

6. The optical lens according to claim 1, characterized in that: The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1.8 < f3 / f < 6.5; The radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -87 < R5 / f < -9; The radius of curvature R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: -6 < R6 / f < -1.

7. The optical lens according to claim 1, characterized in that: The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -181 < f4 / f < -9.5; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -4.8 < R7 / f < -0.75; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -10 < R8 / f < -0.

8.

8. The optical lens according to claim 1, characterized in that: The object-side curvature radius R3 of the second lens and the image-side curvature radius R4 of the second lens satisfy: -0.3 < (R3 - R4) / (R3 + R4) < -0.1; the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: -0.5 < (R7 - R8) / (R7 + R8) < 0.

9. The optical lens according to claim 1, characterized in that: The sagittal height Sag4 of the image-side clear aperture of the second lens and the image-side clear aperture diameter d4 of the second lens satisfy: -0.23 < Sag4 / d4 < -0.09; the sagittal height Sag5 of the object-side clear aperture of the third lens and the object-side clear aperture diameter d5 of the third lens satisfy: -0.14 < Sag5 / d5 < 0.

10. The optical lens according to claim 1, characterized in that: The object-side curvature radius R3 of the second lens, the image-side curvature radius R4 of the second lens and the central thickness CT2 of the second lens satisfy: 0.3 < (R3 + CT2) / R4 < 0.5; the object-side curvature radius R5 of the third lens, the image-side curvature radius R6 of the third lens and the central thickness CT3 of the third lens satisfy: 7 < (R5 + CT3) / R6 < 23.

Images