Optical lens

Abstract

The present invention provides an optical lens, which has a total of seven lenses. Along the optical axis from the object side to the imaging surface, it sequentially includes: a first lens with a negative optical power, whose object side is concave and whose image side is convex; a second lens with a positive optical power, whose object side and image side are both convex; a third lens with a positive optical power, whose object side and image side are both convex; a fourth lens with a negative optical power, whose object side is concave; a fifth lens with a positive optical power, whose object side and image side are both convex; a sixth lens with a positive optical power, whose object side is convex and whose image side is concave; a seventh lens with a negative optical power, whose object side and image side are both concave. The optical lens provided by the present invention has one or more advantages such as long focal length, large aperture, and high imaging quality through specific surface shape matching and reasonable optical power distribution.

Description

Technical Field

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

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

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

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

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

[0006] An optical lens, comprising a total of seven lenses, which sequentially include, 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 concave and the image side surface of which is convex;

[0008] A second lens with positive optical power, the object side surface and the image side surface of which are both convex;

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

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

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

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

[0013] A seventh lens with negative optical power, the object side surface and the image side surface of which are both concave;

[0014] Wherein, the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -0.9 < (R11 - R12) / (R11 + R12) < -0.3.

[0015] Further 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: 0.96 < (IH / 2) / (f×Tan(FOV / 2)) < 0.99; the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.57 / ° < TTL / (IH / 2) / (FOV / 2) < 0.63 / °.

[0016] Further preferably, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.51 < IH / f < 0.55; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.23 < BFL / f < 0.27.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.6 < f1 / f < -1.1; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -0.9 < R1 / f < -0.8; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: -9.6 < R2 / f < -3.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.25 < f2 / f < 1.45; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 1.1.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.5 < f6 / f < 2.7; the curvature radius R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.1 < R11 / f < 1.6; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 2.3 < R12 / f < 16.4.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -0.75 < f7 / f < -0.6; the curvature radius R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -0.65 < R13 / f < -0.5; the curvature radius R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 1.7 < R14 / f < 11.7.

[0021] More preferably, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens, and the seventh lens satisfy: 1.4 < f1234 / f567 < 2.9.

[0022] More preferably, 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: -1 < (R13 + R14) / (R13 - R14) < -0.4.

[0023] More preferably, the clear aperture semi-diameter d12 of the image side surface of the sixth lens and the sagittal height Sag12 of the clear aperture of the image side surface of the sixth lens satisfy: 0 < Sag12 / d12 < 0.06; the clear aperture semi-diameter d13 of the object side surface of the seventh lens and the sagittal height Sag13 of the clear aperture of the object side surface of the seventh lens satisfy: -0.25 < Sag13 / d13 < -0.21.

[0024] The optical lens provided by the present invention uses seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as long focal length, large aperture, and high imaging quality. Description of the Drawings

[0025] 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:

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

[0027] Figure 2 is a field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 3 is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

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

[0030] Figure 5 is the lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 6 is the MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0032] Figure 7It is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0033] Figure 8 It is a field curvature curve graph of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 9 It is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 10 It is an axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 11 It is a lateral chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0037] Figure 12 It is an MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0038] Figure 13 It is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 14 It is a field curvature curve graph of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 15 It is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0041] Figure 16 It is an axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0042] Figure 17 It is a lateral chromatic aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0043] Figure 18 It is an MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0044] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0045] To better understand the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another, and do not represent any limitation on the features. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0047] 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 only examples and are not drawn to an exact scale.

[0048] 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.

[0049] It should also be understood that the terms "comprises," "comprising," "has," "including," and / or "including having," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Further, 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 a single element in the list. Further, 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.

[0050] 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.

[0051] 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.

[0052] The optical lens provided by the embodiment of the present invention is composed of seven lenses, which are, in order from the object side to the imaging surface along the optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0053] In some embodiments, the first lens may have a negative optical power, with its object side being concave and its image side being convex. The second lens may have a positive optical power, with both its object side and image side being convex. The third lens may have a positive optical power, with both its object side and image side being convex. The fourth lens may have a negative optical power, with its object side being concave and its image side being either concave or convex. The fifth lens may have a positive optical power, with both its object side and image side being convex. The sixth lens may have a positive optical power, with its object side being convex and its image side being concave. The seventh lens may have a negative optical power, with both its object side and image side being concave.

[0054] In some embodiments, the optical lens may further include a diaphragm, which may be located between the fourth lens and the fifth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. Additionally, when the diaphragm is located between the fourth lens and the fifth lens, the diaphragm can reasonably distribute the functions of the first lens to the seventh lens. For example, the first lens, the second lens, the third lens, and the fourth lens can be used to receive light to a large extent, and the fifth lens to the seventh lens can be used to correct aberrations, which is beneficial to balancing the structure of the entire optical system. Furthermore, when the diaphragm is located between the fourth lens and the fifth lens, it is convenient to correct the diaphragm aberration.

[0055] In some embodiments, the optical lens may further include a filter and a protective glass, and the filter and the protective glass may be sequentially disposed 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.

[0056] In some embodiments, the third lens and the fourth 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.

[0057] 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: -0.9 < (R11 - R12) / (R11 + R12) < -0.3. Satisfying the above range can make the object side surface and the image side surface close to a concentric circle structure, which is beneficial to making the light enter the rear lens smoothly, reducing the field curvature, correcting the off-axis aberration, and is beneficial to the correction of the aberration of the entire optical lens, improving the imaging quality of the optical lens. More specifically, -0.83 < (R11 - R12) / (R11 + R12) < -0.33.

[0058] 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: 0.96 < (IH / 2) / (f × Tan(FOV / 2)) < 0.99. Satisfying the above range can control the optical lens to have a small distortion and improve the imaging quality.

[0059] In some embodiments, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.57 / ° < TTL / (IH / 2) / (FOV / 2) < 0.63 / °. Satisfying the above range can limit the length of the optical lens under the condition of the same imaging area and the same field of view angle, realizing the miniaturization of the optical lens.

[0060] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.51 < IH / f < 0.55. Satisfying the above range can control the image height and focal length of the optical lens within a reasonable range, which is helpful for the optical lens to have the characteristic of a large image plane and improve the imaging quality.

[0061] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.23 < BFL / f < 0.27. Satisfying the above range can limit the optical lens to have an appropriate back focus, facilitating the reasonable arrangement of the positions of each lens and reducing the processing and assembly difficulty.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.6 < f1 / f < -1.1; 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: -0.9 < R1 / f < -0.8; 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: -9.6 < R2 / f < -3. Meeting the above ranges, by setting the first lens to have a negative refractive power and a suitable surface shape, it is beneficial for the first lens to accommodate a larger angle of light and collect as much light as possible to enter the rear optical system, increasing the light flux while achieving a large field of view. More specifically, -1.6 < f1 / f < -1.14; -0.86 < R1 / f < -0.83; -9.57 < R2 / f < -3.05.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.25 < f2 / f < 1.45. Meeting the above ranges, it is defined that the second lens has an appropriate positive optical power, which has the effect of converging light, reducing the height of peripheral light, being beneficial for reducing the aperture of the rear lens, and at the same time being beneficial for balancing aberrations and improving resolution. More specifically, 1.29 < f2 / f < 1.41.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1 < f3 / f < 1.1. Meeting the above ranges, it is defined that the third lens has an appropriate positive optical power, and the light is further converged. And gluing the third lens with positive optical power and the fourth lens with negative optical power is beneficial for the light to enter the rear lens smoothly, can adjust the optical path difference between different fields of view, and improve resolution. More specifically, 1.01 < f3 / f < 1.09.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.5 < f6 / f < 2.7; 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: 1.1 < R11 / f < 1.6; 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: 2.3 < R12 / f < 16.4. Meeting the above ranges, it is defined that the sixth lens has a positive optical power and a suitable surface shape, which is beneficial for light convergence, enables the light trend to transition smoothly to the rear, reduces the height of the light incident on the rear, slows down the upward trend of the light, avoids the light energy loss caused by the excessive main ray angle of the large field of view light reaching the imaging surface, is beneficial for improving the illuminance of the edge field of view, and is beneficial for achieving a short optical total length. More specifically, 1.55 < f6 / f < 2.62; 1.13 < R11 / f < 1.6; 2.3 < R12 / f < 16.32.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -0.75 < f7 / f < -0.6; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.65 < R13 / f < -0.5; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.7 < R14 / f < 11.7. Satisfying the above ranges can effectively balance various aberrations generated by the front lens group, and at the same time is conducive to increasing the divergence degree of light, increasing the area of light entering the imaging surface, realizing large-format imaging of the lens, and improving the imaging quality of the optical lens. More specifically, -0.71 < f7 / f < -0.62; -0.61 < R13 / f < -0.53; 1.75 < R14 / f < 11.62.

[0067] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: 1.4 < f1234 / f567 < 2.9. Satisfying the above ranges is conducive to balancing various aberrations of the system and improving the overall imaging quality by reasonably setting the relationship between the lens groups before and after the aperture. More specifically, 1.42 < f1234 / f567 < 2.84.

[0068] In some embodiments, the object-side curvature radius R13 of the seventh lens and the image-side curvature radius R14 of the seventh lens satisfy: -1 < (R13 + R14) / (R13 - R14) < -0.4. Satisfying the above ranges, controlling the surface shape of the seventh lens is conducive to increasing the imaging area and field of view angle of the optical lens, conducive to balancing the aberrations of the optical lens, and improving the imaging quality of the optical lens. More specifically, -0.92 < (R13 + R14) / (R13 - R14) < -0.48.

[0069] In some embodiments, the image-side clear aperture semi-diameter d12 of the sixth lens and the image-side clear aperture sagittal height Sag12 of the sixth lens satisfy: 0 < Sag12 / d12 < 0.06; the object-side clear aperture semi-diameter d13 of the seventh lens and the object-side clear aperture sagittal height Sag13 of the seventh lens satisfy: -0.25 < Sag13 / d13 < -0.21. Satisfying the above ranges helps to control the trend of marginal field light and highlight the detailed information of the central field of the optical lens.

[0070] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.4 < TTL / f < 2.5. Satisfying the above ranges can effectively limit the length of the lens while achieving a long focal length, which is conducive to the miniaturization of the optical lens. More specifically, 2.41 < TTL / f < 2.5.

[0071] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 4.4 < TTL / IH < 4.7. Meeting the above range ensures that, with the same total length of the lens, a larger image plane is obtained, enabling it to match a larger-sized imaging chip to achieve high-definition imaging and better achieving the balance between the small total length and the large image plane of the lens. More specifically, 4.49 < TTL / IH < 4.63.

[0072] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 17° < FOV / Fno < 19°. Meeting the above range defines that the optical lens has an appropriate field of view angle and aperture value, enabling it to collect light at a large angle and obtain good imaging quality. More specifically, 17.21° < FOV / Fno < 18.76°.

[0073] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.8 < IH / EPD < 1. Meeting the above range can increase the width of the light beam incident on the optical lens, enhancing the brightness at the image plane of the optical lens and avoiding the generation of vignetting. More specifically, 0.83 < IH / EPD < 0.98.

[0074] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.6 < ∑CT / TTL < 0.65. Meeting the above range can effectively compress the total length of the optical lens and is conducive to the structural design and production process of the optical lens.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1 < f4 / f < -0.8. Meeting the above range defines that the fourth lens has an appropriate negative optical power, which can diverge the light rays emerging from the third lens, making the light rays in the peripheral field of view show an upward trend, facilitating the image points on the imaging plane to be away from the optical axis, which is conducive to achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberrations, and improving the resolution of the optical lens. More specifically, -1.11 < f4 / f < -0.86.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.21 < f5 / f < 1.42; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < R9 / f < 0.9; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -3.6 < R10 / f < -1.9. Meeting the above ranges and setting the fifth lens to have a positive refractive power and a suitable surface shape is conducive to converging light while correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens. More specifically, 1.21 < f5 / f < 1.42; 0.71 < R9 / f < 0.84; -3.51 < R10 / f < -1.99.

[0077] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -0.7 < (R9 + R10) / (R9 - R10) < -0.4. Meeting the above range is conducive to the smooth transition of light, can effectively correct the distortion of the edge field of view, reduce the degree of deformation of the edge of the captured image, and improve the image quality. More specifically, -0.67 < (R9 + R10) / (R9 - R10) < -0.41.

[0078] In some embodiments, the optical lens satisfies the following conditional expressions: 12 mm < f < 13.5 mm; 29° < FOV < 32°; 7 mm < EPD < 8.2 mm; 30 mm < TTL < 32 mm; 1.5 < Fno < 1.9; 6.5 mm < IH < 7 mm; 21° < CRA < 23°; 3.1 mm < BFL < 3.2 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the overall optical length of the optical lens, FNO represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray angle of incidence of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and a long focal length characteristic. More specifically, 12.25 mm < f < 13.06 mm; 7.02 mm < EPD < 8.17 mm; 30.56 mm < TTL < 31.65 mm; 1.59 < Fno < 1.81; 21.14° < CRA < 22.62°; 3.17 mm < BFL < 3.19 mm; 29.9° < FOV < 31.1°; 6.62 mm < IH < 6.85 mm.

[0079] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0080] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt spherical lenses or aspherical lenses. Compared with the spherical lens structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens of the present invention adopt spherical lenses.

[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 partially different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0082] Embodiment 1

[0083] Please refer to Figure 1 , which shows a schematic structural diagram of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a diaphragm ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0084] 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 convex surface;

[0085] The second lens L2 has a positive optical power. Its object side S3 is a convex surface, and its image side S4 is a convex surface;

[0086] The third lens L3 has a positive optical power. Its object side S5 and image side are both convex surfaces;

[0087] The fourth lens L4 has a negative optical power. Its object side is a concave surface, and its image side S7 is a concave surface;

[0088] The third lens L3 and the fourth lens L4 form a cemented lens group with a negative optical power, that is, the cemented surface of the image side of the third lens L3 and the object side of the fourth lens L4 is S6;

[0089] The fifth lens L5 has a positive optical power, and its object side S8 and image side S9 are both convex surfaces;

[0090] The sixth lens L6 has a positive optical power, its object side S10 is a convex surface, and its image side S11 is a concave surface;

[0091] The seventh lens L7 has a negative optical power, its object side S12 is a concave surface, and its image side S13 is a concave surface;

[0092] The object side S14 and the image side S15 of the filter G1 are both flat surfaces;

[0093] The object side S16 and the image side S17 of the protective glass G2 are both flat surfaces;

[0094] The imaging surface S18 is a flat surface.

[0095] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, and the seventh lens L7 adopt glass spherical lenses.

[0096] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1.

[0097] Table 1

[0098]

[0099] In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve, axial aberration curve graph, lateral chromatic aberration curve graph, and MTF curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 shown.

[0100] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the bending degree of light rays with different wavelengths in the meridional image plane and the sagittal image plane. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the 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 -0.02 mm to 0.04 mm, indicating that the optical lens can well correct the field curvature.

[0101] Figure 3The F-Tan(Theta) distortion curve of Embodiment 1 is shown, which represents the F-Tan(Theta) distortion of light rays with different wavelengths at different image heights on the imaging surface. The horizontal axis represents the F-Tan(Theta) distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the F-Tan(Theta) distortion of the optical lens is controlled within -3% to 0, indicating that the optical lens can correct distortion well.

[0102] Figure 4 The axial aberration curve graph of Embodiment 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within -0.01 mm to 0.04 mm, indicating that the optical lens can correct axial aberration well.

[0103] Figure 5 The lateral chromatic aberration curve graph of Embodiment 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging surface. The horizontal axis represents the lateral chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1 μm to 2 μm, indicating that the optical lens can correct chromatic aberration extremely well.

[0104] Figure 6 The MTF (Modulation Transfer Function) curve graph of Embodiment 1 is shown, which represents the modulation of the lens imaging at different spatial frequencies under each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.38 within the entire field of view. In the range of 0 to 180 lp / mm, the MTF curve decreases uniformly and smoothly from the central field of view to the edge field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0105] Embodiment 2

[0106] Please refer to Figure 7 , which shows the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main difference is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

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

[0108] Table 2

[0109]

[0110] In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve, axial aberration curve graph, lateral chromatic aberration curve graph, and MTF curve graph of the optical lens 200 are respectively as shown in Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 .

[0111] It can be seen from Figure 8 that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.02 mm to 0.03 mm, indicating that the optical lens 200 can correct the field curvature well.

[0112] It can be seen from Figure 9 that the F-Tan(Theta) distortion of the optical lens 200 is controlled within -3% to 0, indicating that the optical lens 200 can correct the distortion relatively well.

[0113] It can be seen from Figure 10 that the offset of the axial aberration is controlled within -0.01 mm to 0.03 mm, indicating that the optical lens 200 can correct the axial aberration relatively well.

[0114] It can be seen from Figure 11 that the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1 μm to 2 μm, indicating that the optical lens 200 can correct the chromatic aberration extremely well.

[0115] It can be seen from Figure 12 that the MTF value of this embodiment is above 0.38 within the entire field of view. In the range of 0 to 180 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.

[0116] Embodiment 3

[0117] Please refer to Figure 13 . The structure diagram of the optical lens 300 provided in Embodiment 3 of the present invention is shown. Compared with Embodiment 1, the main differences are as follows: The third lens L3 and the fourth lens L4 form a cemented lens group with positive optical power; the image side surface S7 of the fourth lens L4 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0118] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3.

[0119] Table 3

[0120]

[0121] In this embodiment, the field curvature curve graph, F-Tan(Theta) distortion curve, axial aberration curve graph, lateral chromatic aberration curve graph, and MTF curve graph of the optical lens 300 are respectively as Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 shown.

[0122] It can be seen from Figure 14 that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.01 mm to 0.03 mm, indicating that the optical lens 300 can well correct the field curvature.

[0123] It can be seen from Figure 15 that the F-Tan(Theta) distortion of the optical lens 300 is controlled within -3% to 0, indicating that the optical lens 300 can better correct the distortion.

[0124] It can be seen from Figure 16 that the offset of the axial aberration is controlled within -0.01 mm to 0.03 mm, indicating that the optical lens 300 can better correct the axial aberration.

[0125] It can be seen from Figure 17 that the lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1 μm to 2 μm, indicating that the optical lens 300 can excellently correct the chromatic aberration.

[0126] It can be seen from Figure 18 that the MTF value of this embodiment is above 0.48 within the entire field of view. In the range of 0 to 180 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.

[0127] Please refer to Table 4 for the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the true image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, and the values corresponding to each conditional formula in each embodiment.

[0128] Table 4

[0129]

[0130] In summary of the above embodiments, the optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, enabling the lens to have one or more advantages such as long focal length, large aperture, and high imaging quality.

[0131] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions 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.

[0132] The above-described embodiments merely represent several implementation manners of the present invention. The 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 shall be subject to the appended claims.

Claims

1. An optical lens, consisting of seven lenses in total, characterized in that, Along the optical axis from the object side to the imaging surface, it includes: The first lens has a negative optical power, the object side surface of which is concave and the image side surface of which is convex; The second lens has positive refractive power, and its object side surface and image side surface are both convex; The third lens has positive refractive power, and both the object side surface and the image side surface are convex; a fourth lens element having negative optical power and a concave object side surface; A fifth lens having positive refractive power, whose object-side surface and image-side surface are both convex; a sixth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is concave; The seventh lens element has negative optical power, and both the object side surface and the image side surface are concave; The object side curvature radius R11 of the sixth lens and the image side curvature radius R12 of the sixth lens satisfy: -0.9<(R11-R12) / (R11+R12)<-0.3; the total optical length TTL of the optical lens, the real image height IH corresponding to the maximum field of view of the optical lens and the maximum field of view FOV of the optical lens satisfy: 0.57 / ° <TTL / (IH / 2) / (FOV / 2)<0.63 / °。 2. The optical lens according to claim 1, characterized in that The real image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.96<(IH / 2) / (f×Tan(FOV / 2))<0.99; the object side surface radius of curvature R11 of the sixth lens and the image side surface radius of curvature R12 of the sixth lens satisfy: -0.83<(R11-R12) / (R11+R12)<-0.

33.

3. The optical lens according to claim 1, characterized in that, The real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.51 <IH / f<0.55;所述光学镜头的有效焦距f与所述光学镜头的后焦距BFL满足:0.23<BFL / f<0.27。 4. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.6 <f1 / f<-1.1;所述第一透镜的物侧面曲率半径R1与所述光学镜头的有效焦距f满足:-0.9<R1 / f<-0.8;所述第一透镜的像侧面曲率半径R2与所述光学镜头的有效焦距f满足:-9.6<R2 / f<-3。 5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.25 <f2 / f<1.45;所述光学镜头的有效焦距f与所述第三透镜的焦距f3满足:1<f3 / f<1.1。 6. The optical lens according to claim 1, wherein, The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.5 <f6 / f<2.7;所述第六透镜的物侧面曲率半径R11与所述光学镜头的有效焦距f满足:1.1<R11 / f<1.6;所述第六透镜的像侧面曲率半径R12与所述光学镜头的有效焦距f满足:2.3<R12 / f<16.4。 7. The optical lens according to claim 1, wherein The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -0.75 < f7 / f < -0.6; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.65 < R13 / f < -0.5; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 1.7 < R14 / f < 11.

7.

8. The optical lens according to claim 1, characterized in that The combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens, and the seventh lens satisfy: 1.4 < f1234 / f567 < 2.

9.

9. The optical lens according to claim 1, wherein The object-side curvature radius R13 of the seventh lens and the image-side curvature radius R14 of the seventh lens satisfy: -1 < (R13 + R14) / (R13 - R14) < -0.

4.

10. The optical lens according to claim 1, characterized in that, The image-side clear aperture semi-diameter d12 of the sixth lens and the image-side clear aperture sagittal height Sag12 of the sixth lens satisfy: 0 < Sag12 / d12 < 0.06; the object-side clear aperture semi-diameter d13 of the seventh lens and the object-side clear aperture sagittal height Sag13 of the seventh lens satisfy: -0.25 < Sag13 / d13 < -0.21.

Images