Optical lens

Abstract

The invention provides an optical lens, which comprises seven lenses in total, 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 second lens has positive focal power; the third lens has positive focal power; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; and the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a convex surface. The optical lens provided by the invention has one or more advantages of large target surface, large aperture, small distortion 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] At present, with the booming development of automotive assisted driving and autonomous driving technologies, in-vehicle cameras play a crucial role. There are various types of in-vehicle cameras, including interior view, rear view, front view, side view, surround view, etc. They each have unique functions and different application scenarios. For example, the main function of the front-view wide-angle camera is to accurately identify nearby objects, and in scenarios such as urban road conditions and low-speed vehicle driving, it can provide key information for driving.

[0003] The front-view camera is a core component of the ADAS (Advanced Driving Assistance System). It not only shoulders the important task of ranging, but also can accurately identify objects and clearly distinguish road markings. Therefore, the visual algorithms required for it are extremely complex and the technical threshold is quite high. In order to fully utilize the performance of the front-view camera, it is urgent to develop an optical lens with excellent imaging effects. Only in this way can it work stably and efficiently in complex driving environments and lay a solid foundation for the further development of autonomous driving technology. Summary of the Invention

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

[0005] The technical solution adopted by the present invention is as follows: An optical lens, comprising a total of seven lenses, which successively include from the object side to the imaging surface along the optical axis: A first lens with negative optical power, the object side surface of which is concave and the image side surface of which is concave; A second lens with positive optical power; A third lens with positive optical power; A fourth lens with positive optical power, the object side surface of which is convex and the image side surface of which is convex; A fifth lens with negative optical power, the object side surface of which is concave and the image side surface of which is concave; A sixth lens with positive optical power, the object side surface of which is concave and the image side surface of which is convex; A seventh lens with negative optical power, the object side surface of which is concave and the image side surface of which is convex; Wherein, the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: -0.6 < (R13 - R14) / (R13 + R14) < -0.2; the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: -0.8 < (R1 + R2) / (R1 - R2) < -0.4.

[0006] More preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < TTL / f < 2.3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 3.7.

[0007] More preferably, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 21° < FOV / Fno < 22°; 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: 0.9 < IH / EPD < 1.1.

[0008] More preferably, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.26 < BFL / f < 0.33; the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.11 < BFL / TTL < 0.17.

[0009] More preferably, the half 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: 3.6 < d1 / (IH / 2) / tan(FOV / 2) < 4.5; the combined focal length f34567 of the third, fourth, fifth, sixth, and seventh lenses and the effective focal length f of the optical lens satisfy: 0.8 < f34567 / f < 1.8.

[0010] More preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < f1 / f < -0.5; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < R1 / f < -0.5; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1.8 < R2 / f < 5.6.

[0011] More preferably, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.7 < f4 / f < 0.9; the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R7 / f < 1.1; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -2.1 < R8 / f < -0.6.

[0012] Further preferably, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 1.7; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -18 < R11 / f < -3; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.1 < R12 / f < -0.7.

[0013] Further preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < f7 / f < -1.1; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.6 < R13 / f < -0.4; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < R14 / f < -0.7.

[0014] Further preferably, the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 1; the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: |(R7 + R8) / (R7 - R8)| < 0.6.

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

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

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

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

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

[0020] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0021] Figure 6 It is the field curvature curve graph of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 7 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 2 of the present invention.

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

[0024] Figure 9 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0025] Figure 10 It is the field curvature curve graph of the optical lens in Embodiment 3 of the present invention.

[0026] Figure 11 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0027] Figure 12 It is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 13 It is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0029] Figure 14 It is the field curvature curve graph of the optical lens in Embodiment 4 of the present invention.

[0030] Figure 15 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0031] Figure 16 It is the MTF curve graph of the optical lens in Embodiment 4 of the present invention.

[0032] Figure 17 It is the structural schematic diagram of the optical lens in Embodiment 5 of the present invention.

[0033] Figure 18 It is the field curvature curve graph of the optical lens in Embodiment 5 of the present invention.

[0034] Figure 19 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 5 of the present invention.

[0035] Figure 20 It is the MTF curve graph of the optical lens in Embodiment 5 of the present invention.

[0036] Figure 21 It is the structural schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0037] Figure 22 It is the field curvature curve graph of the optical lens in Embodiment 6 of the present invention.

[0038] Figure 23 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 6 of the present invention.

[0039] Figure 24 It is the MTF curve graph of the optical lens in Embodiment 6 of the present invention.

[0040] Figure 25 It is the structural schematic diagram of the optical lens in Embodiment 7 of the present invention.

[0041] Figure 26 It is the field curvature curve graph of the optical lens in Embodiment 7 of the present invention.

[0042] Figure 27 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 7 of the present invention.

[0043] Figure 28 It is the MTF curve graph of the optical lens in Embodiment 7 of the present invention.

[0044] Figure 29 It is the structural schematic diagram of the optical lens in Embodiment 8 of the present invention.

[0045] Figure 30 It is the field curvature curve graph of the optical lens in Embodiment 8 of the present invention.

[0046] Figure 31 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 8 of the present invention.

[0047] Figure 32 It is the MTF curve graph of the optical lens in Embodiment 8 of the present invention.

[0048] The following specific embodiments will further illustrate the present invention in combination with the above-mentioned drawings. Specific Embodiments

[0049] To better understand the present application, more detailed descriptions will be made for various aspects of the present application with reference to the 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.

[0050] 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.

[0051] In the drawings, for ease of illustration, the thickness, dimensions, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only examples and are not drawn to an exact scale.

[0052] In this document, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0053] It should also be understood that the terms "comprising", "including", "having", "containing", 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 modifying 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.

[0054] 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.

[0055] 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 the embodiments.

[0056] 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.

[0057] In some embodiments, the first lens may have a negative optical power, its object side may be concave, and its image side may be concave. The second lens may have a positive optical power, its object side may be convex or concave, and its image side may be concave or convex. The third lens may have a positive optical power, its object side may be convex or concave, and its image side may be convex or concave. The fourth lens may have a positive optical power, its object side may be convex, and its image side may be convex. The fifth lens may have a negative optical power, its object side may be concave, and its image side may be concave. The sixth lens may have a positive optical power, its object side may be concave, and its image side may be convex. The seventh lens may have a negative optical power, its object side may be concave, and its image side may be convex.

[0058] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the second lens and the third lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging. When the diaphragm is located between the second lens and the third lens, it is convenient for correcting the diaphragm aberration.

[0059] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially arranged along the optical axis between the seventh lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the anti-impact and scratch-resistant capabilities of the optical lens, while having almost no impact on the imaging quality of the optical lens.

[0060] In some embodiments, the fourth lens and the fifth lens may be glued together to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity 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.

[0061] In some embodiments, the radius of curvature R13 of the object side of the seventh lens and the radius of curvature R14 of the image side of the seventh lens satisfy: -0.6 < (R13 - R14) / (R13 + R14) < -0.2; the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: -0.8 < (R1 + R2) / (R1 - R2) < -0.4. Meeting the above ranges and controlling the seventh lens and the first lens to have appropriate surface shapes is beneficial to increasing the divergence degree of light, achieving large target surface imaging of the lens, and improving the imaging quality of the optical lens. More specifically: -0.56 < (R13 - R14) / (R13 + R14) < -0.23; -0.77 < (R1 + R2) / (R1 - R2) < -0.48.

[0062] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < TTL / f < 2.3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 3.7. Meeting the above ranges is conducive to achieving the balance of a small volume and a large image plane of the optical lens, making the lens have a smaller total length. More specifically: 1.91 < TTL / f < 2.22; 3.06 < TTL / IH < 3.58.

[0063] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 21° < FOV / Fno < 22°; 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: 0.9 < IH / EPD < 1.1. Meeting the above ranges reasonably limits the ratio of the field of view angle to the aperture value, enabling the collection of light at large angles and obtaining good imaging quality. At the same time, reasonably limiting the ratio of the image height to the entrance pupil diameter is conducive to increasing the light transmission amount, making the peripheral field of view and the central field of view brighter and more uniform. More specifically: 21.2° < FOV / Fno < 21.89°; 0.98 < IH / EPD < 1.04.

[0064] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.26 < BFL / f < 0.33; the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.11 < BFL / TTL < 0.17. Meeting the above ranges limits the optical lens to have an appropriate back focus, facilitating the reasonable arrangement of the positions of each lens, while reducing the processing and assembly difficulty. At the same time, it is beneficial to reduce the interference between different components and improve the yield.

[0065] In some embodiments, the clear aperture radius d1 of the object side of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 3.6 < d1 / (IH / 2) / tan(FOV / 2) < 4.5; the combined focal length f34567 of the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 0.8 < f34567 / f < 1.8. Meeting the above ranges can reasonably arrange the overall geometry of the optical lens and improve its structural stability. At the same time, reasonably limiting the proportion of the optical power of the lens group behind the diaphragm is conducive to correcting the chromatic aberration and field curvature of the optical system, as well as reducing the light deflection angle, reducing the sensitivity, and reducing the lens forming difficulty. More specifically: 3.65 < d1 / (IH / 2) / tan(FOV / 2) < 4.47; 0.82 < f34567 / f < 1.77.

[0066] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < f1 / f < -0.5; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < R1 / f < -0.5; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1.8 < R2 / f < 5.6. Meeting the above ranges, by reasonably defining the proportion of the optical power of the first lens and its surface shape, the light passing through it can be diverged, which is beneficial to achieving a small front aperture. More specifically: -1.57 < f1 / f < -0.57; -1.63 < R1 / f < -0.59; 1.88 < R2 / f < 5.59.

[0067] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.7 < f4 / f < 0.9; 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: 0.6 < R7 / f < 1.1; 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: -2.1 < R8 / f < -0.6. Meeting the above ranges, by reasonably defining the proportion of the optical power of the fourth lens and its surface shape, the aberration of the optical lens can be effectively corrected, and the imaging quality can be improved. More specifically: 0.71 < f4 / f < 0.89; 0.65 < R7 / f < 1.04; -2.06 < R8 / f < -0.69.

[0068] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 1.7; the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -18 < R11 / f < -3; the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -1.1 < R12 / f < -0.7. Meeting the above ranges, by reasonably defining the proportion of the optical power of the sixth lens and its surface shape, it is beneficial for the convergence of light, enabling the light trend to smoothly transition to the rear, reducing the height of the light incident on the rear, slowing down the upward trend of the light, and being beneficial to improving the illuminance of the edge field of view. More specifically: 1.07 < f6 / f < 1.64; -17.66 < R11 / f < -3.27; -1.04 < R12 / f < -0.76.

[0069] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < f7 / f < -1.1; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -0.6 < R13 / f < -0.4; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < R14 / f < -0.7. Satisfying the above ranges and reasonably defining the refractive power ratio and surface shape of the seventh lens is beneficial to increasing the divergence degree of light rays, increasing the area of light rays entering the imaging surface, achieving large target surface imaging of the lens, and improving the imaging quality of the optical lens. More specifically: -1.77 < f7 / f < -1.19; -0.53 < R13 / f < -0.41; -1.76 < R14 / f < -0.7.

[0070] In some embodiments, the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 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: |(R7 + R8) / (R7 - R8)| < 0.6. Satisfying the above ranges and controlling the sixth lens and the fourth lens to have appropriate surface shapes is beneficial to light convergence, enabling the light path to smoothly transition to the rear, reducing the height of light rays incident on the rear, slowing down the upward trend of light rays, and being beneficial to improving the illuminance of the edge field of view. Moreover, it can effectively correct the aberration of the optical lens and improve the imaging quality. More specifically: 0.53 < (R11 - R12) / (R11 + R12) < 0.91; -0.45 < (R7 + R8) / (R7 - R8) < 0.2.

[0071] 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: 0.97 < (IH / 2) / (f × tan(FOV / 2)) < 1.01. Satisfying the above range can control the optical lens to have less distortion and improve the imaging quality.

[0072] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the total optical length TTL of the optical lens satisfy: 0.58 < ΣCT / TTL < 0.7. Satisfying the above range and controlling the total 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.

[0073] 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: 1.13 < ΣCT / f < 1.53. By satisfying the above range and controlling the effective focal length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range, the lens can be made more compact.

[0074] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.8 < f2 / f < 1.7. By satisfying the above range and reasonably defining the proportion of the optical power of the second lens, it has the effect of converging light rays, depressing the height of peripheral light rays, and is beneficial to reducing the aperture of the rear lens. More specifically: 0.8 < f2 / f < 1.56.

[0075] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 0.9 < f3 / f < 2.4. By satisfying the above range and reasonably defining the proportion of the optical power of the third lens, 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: 0.96 < f3 / f < 2.38.

[0076] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.7 < f5 / f < -0.4; the object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.1 < R9 / f < -0.6; the image-side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.5 < R10 / f < 1. By satisfying the above range and reasonably defining the proportion of the optical power of the fifth lens and its surface shape, spherical aberration can be optimized to achieve high-quality imaging. More specifically: -0.65 < f5 / f < -0.45; -2.06 < R9 / f < -0.69; 0.52 < R10 / f < 0.92.

[0077] In some embodiments, the optical lens satisfies the following conditional expressions: 14 mm < f < 16 mm; 30° < FOV < 40°; 9 mm < EPD < 10 mm; 29 mm < TTL < 33 mm; 1.5 < Fno < 1.7; 8.5 mm < IH < 10 mm; 17° < CRA < 22°; 3.5 mm < BFL < 5.5 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the 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 low distortion. More specifically: 14.47 mm < f < 15.62 mm; 34° < FOV < 36°; 9.04 mm < EPD < 9.76 mm; 29.23 mm < TTL < 32.07 mm; 1.59 < Fno < 1.66; 8.97 mm < IH < 9.76 mm; 17.31° < CRA < 21.59°; 3.96 mm < BFL < 5.01 mm.

[0078] 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, 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.

[0079] 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 second lens of the present invention adopts an aspherical lens, and the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens adopt spherical lenses.

[0080] In each embodiment of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; Among them, z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, F are the conic coefficients of the fourth, sixth, eighth, tenth, and twelfth orders respectively.

[0081] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, curvature radius, and material selection of each lens in the optical lens are somewhat different. For specific differences, refer to the parameter tables of each embodiment. The following embodiments are only 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.

[0082] Embodiment 1 Please refer to Figure 1 , which shows a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, a diaphragm ST, a third lens L3, 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 S1 is a concave surface, and its image side S2 is a concave surface; The second lens L2 has a positive optical power, its object side S3 is a convex surface, and its image side S4 is a concave surface; The third lens L3 has a positive optical power, its object side S5 is a convex surface, and its image side S6 is a convex surface; The fourth lens L4 has a positive optical power, its object side S7 is a convex surface, and its image side S8 is a convex surface; The fifth lens L5 has a negative optical power, its object side S8 is a concave surface, and its image side S9 is a concave surface; The fourth lens L4 and the fifth lens L5 form a cemented lens group, that is, the cemented surface of the image side of the fourth lens L4 and the object side of the fifth lens L5 is S8; The sixth lens L6 has a positive optical power, its object side S10 is a concave surface, and its image side S11 is a convex surface; The seventh lens L7 has a negative optical power, its object side S12 is a concave surface, and its image side S13 is a convex surface; Both the object side S14 and the image side S15 of the filter G1 are flat surfaces; Both the object side S16 and the image side S17 of the protective glass G2 are flat surfaces; The imaging surface S18 is a flat surface.

[0084] The second lens L2 is a glass aspherical lens, and the first lens L1, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses.

[0085] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0086] Table 1-1 The surface type parameters of the aspherical lens of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0087] Table 1-2 In this embodiment, the field curvature curve graph, the F-Tan(Theta) distortion curve graph, and the MTF curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 shown.

[0088] Figure 2 The field curvature curve graph of Embodiment 1 is shown, which represents the bending degree of light rays of different wavelengths in the meridional image plane and the sagittal image plane. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.06 mm, indicating that the optical lens 100 can correct the field curvature well.

[0089] Figure 3 The F-Tan(Theta) distortion curve graph of Embodiment 1 is shown, which represents the distortion of light rays of different wavelengths at different image heights on the imaging plane. 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 -0.2% to 0%, indicating that the optical lens 100 can correct the distortion well.

[0090] Figure 4 The MTF (Modulation Transfer Function) curve graph of Embodiment 1 is shown, 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 in this embodiment is above 0.4 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0091] Embodiment 2 Please refer to Figure 5, which shows a schematic structural diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main differences are as follows: the object side surface S3 of the second lens L2 is concave, and the image side surface S4 is convex; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0092] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0093] Table 2-1 The surface type parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0094] Table 2-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, and MTF curve graph of the optical lens 200 are respectively as shown in Figure 6 , Figure 7 , Figure 8 . It can be seen from Figure 6 that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.08 mm to 0.04 mm, indicating that the optical lens 200 can correct the field curvature well. It can be seen from Figure 7 that the distortion of the optical lens 200 is controlled within -1.8% to 0%, indicating that the optical lens 200 can correct the distortion better. It can be seen from Figure 8 that the MTF value in this embodiment is above 0.3 within 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.

[0095] Embodiment 3 Please refer to Figure 9 , which shows a schematic structural diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main differences are as follows: the image side surface S4 of the second lens L2 is convex; the object side surface S5 of the third lens L3 is concave; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0096] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0097] Table 3-1 The surface type parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0098] Table 3-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, and MTF curve graph of the optical lens 300 are respectively as shown in Figure 10 , Figure 11 , Figure 12 . It can be seen from Figure 10 that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.04 mm, indicating that the optical lens 300 can correct the field curvature well. It can be seen from Figure 11 that the distortion of the optical lens 300 is controlled within -0.9% to 0%, indicating that the optical lens 300 can correct the distortion better. It can be seen from Figure 12 that the MTF value of this embodiment is above 0.3 within 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.

[0099] Embodiment 4 Please refer to Figure 13 , which shows the structural schematic diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main differences are: the image side S4 of the second lens L2 is a convex surface; the image side S6 of the third lens L3 is a concave surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0100] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0101] Table 4-1 The aspheric lens surface type parameters of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0102] Table 4-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, and MTF curve graph of the optical lens 400 are respectively as shown in Figure 14 , Figure 15 , Figure 16 . It can be seen from Figure 14 that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.04 mm, indicating that the optical lens 400 can correct the field curvature well. It can be seen from Figure 15 that the distortion of the optical lens 400 is controlled within -1% to 0%, indicating that the optical lens 400 can correct the distortion better.Figure 16 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.

[0103] Embodiment 5 Please refer to Figure 17 , 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 as follows: the image side S4 of the second lens L2 is a convex surface; the image side S6 of the third lens L3 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0104] The relevant parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0105] Table 5-1 The surface type parameters of the aspherical lens of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0106] Table 5-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, and MTF curve graph of the optical lens 500 are respectively as shown in Figure 18 , Figure 19 , Figure 20 shown. It can be seen from Figure 18 that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.04 mm, indicating that the optical lens 500 can well correct the field curvature. It can be seen from Figure 19 that the distortion of the optical lens 500 is controlled within -1.2% to 0%, indicating that the optical lens 500 can better correct the distortion. It can be seen from Figure 20 that the MTF value of this embodiment is above 0.5 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.

[0107] Embodiment 6 Please refer to Figure 21 , 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 S4 of the second lens L2 is a convex surface; the object side S5 of the third lens L3 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0108] The relevant parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0109] Table 6-1 The surface type parameters of the aspherical lens of the optical lens 600 in Embodiment 6 are shown in Table 6-2.

[0110] Table 6-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, and MTF curve graph of the optical lens 600 are respectively as Figure 22 , Figure 23 , Figure 24 shown. It can be seen from Figure 22 that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.04 mm to 0.06 mm, indicating that the optical lens 600 can correct the field curvature well. It can be seen from Figure 23 that the distortion of the optical lens 600 is controlled within -1.2% to 0%, indicating that the optical lens 600 can correct the distortion better. It can be seen from Figure 24 that the MTF value of this embodiment is above 0.4 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0111] Embodiment 7 Please refer to Figure 25 , 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: the image side surface S4 of the second lens L2 is a convex surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0112] The relevant parameters of each lens in the optical lens 700 in Embodiment 7 are shown in Table 7-1.

[0113] Table 7-1 The surface type parameters of the aspherical lens of the optical lens 700 in Embodiment 7 are shown in Table 7-2.

[0114] Table 7-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, and MTF curve graph of the optical lens 700 are respectively as Figure 26 ,Figure 27 , Figure 28 as shown. It can be seen from Figure 26 that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.02 mm to 0.04 mm, indicating that the optical lens 700 can correct the field curvature well. It can be seen from Figure 27 that the distortion of the optical lens 700 is controlled within -1.2% to 0%, indicating that the optical lens 700 can correct the distortion well. It can be seen from Figure 28 that the MTF value of this embodiment is above 0.6 within 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.

[0115] Embodiment 8 Please refer to Figure 29 , 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 S4 of the second lens L2 is a convex surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0116] The relevant parameters of each lens in the optical lens 800 in Embodiment 8 are shown in Table 8-1.

[0117] Table 8-1 The aspheric lens surface type parameters of the optical lens 800 in Embodiment 8 are shown in Table 8-2.

[0118] Table 8-2 In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve graph, and MTF curve graph of the optical lens 800 are respectively as shown in Figure 30 , Figure 31 , Figure 32 as shown. It can be seen from Figure 30 that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.04 mm to 0.02 mm, indicating that the optical lens 800 can correct the field curvature well. It can be seen from Figure 31 that the distortion of the optical lens 800 is controlled within -1.2% to 0%, indicating that the optical lens 800 can correct the distortion well. It can be seen from Figure 32 that the MTF value of this embodiment is above 0.6 within 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.

[0119] Please refer to Table 9-1 and Table 9-2 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.

[0120] Table 9-1 Table 9-2 In summary of the above embodiments, the optical lens provided by the present invention uses seven lenses with specific optical powers. Through specific surface shape 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 small distortion.

[0121] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0122] The above-described embodiments merely 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, consisting of seven lenses in total, characterized in that, It sequentially includes, from the object side to the imaging surface along the optical axis: A first lens with negative optical power, whose object side is concave and whose image side is concave; A second lens with positive optical power; A third lens with positive optical power; A fourth lens with positive optical power, whose object side is convex and whose image side is convex; A fifth lens with negative optical power, whose object side is concave and whose image side is concave; A sixth lens with positive optical power, whose object side is concave and whose image side is convex; A seventh lens with negative optical power, whose object side is concave and whose image side is convex; Wherein, the radius of curvature R13 of the object side of the seventh lens and the radius of curvature R14 of the image side of the seventh lens satisfy: -0.6 < (R13 - R14) / (R13 + R14) < -0.2; the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: -0.8 < (R1 + R2) / (R1 - R2) < -0.

4.

2. The optical lens according to claim 1, wherein The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.8 < TTL / f < 2.3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 3 < TTL / IH < 3.

7.

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: 21° < FOV / Fno < 22°; 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: 0.9 < IH / EPD < 1.

1.

4. The optical lens according to claim 1, characterized in that, The back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.26 < BFL / f < 0.33; the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0.11 < BFL / TTL < 0.

17.

5. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter 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: 3.6 < d1 / (IH / 2) / tan(FOV / 2) < 4.5; the combined focal length f34567 of the third, fourth, fifth, sixth and seventh lenses and the effective focal length f of the optical lens satisfy: 0.8 < f34567 / f < 1.

8.

6. The optical lens according to claim 1, characterized in that, The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < f1 / f < -0.5; the radius of curvature R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -1.7 < R1 / f < -0.5; the radius of curvature R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: 1.8 < R2 / f < 5.

6.

7. The optical lens according to claim 1, wherein, The focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.7 < f4 / f < 0.9; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R7 / f < 1.1; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.1 < R8 / f < -0.

6.

8. The optical lens according to claim 1, characterized in that, The focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 1.7; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: -18 < R11 / f < -3; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.1 < R12 / f < -0.

7.

9. The optical lens according to claim 1, characterized in that The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < f7 / f < -1.1; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.6 < R13 / f < -0.4; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.8 < R14 / f < -0.

7.

10. The optical lens according to claim 1, characterized in that, The object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: 0.5 < (R11 - R12) / (R11 + R12) < 1; the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: |(R7 + R8) / (R7 - R8)| < 0.6.

Images