Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses in sequence along an optical axis from an object side to an imaging surface, and comprises the following: a first lens with positive refractive power; a second lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a third lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a fourth lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a fifth lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a sixth lens with positive refractive power, the object side surface of which is a convex surface; and a seventh lens with negative refractive power, the object side surface of which is a concave surface; the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy the condition: |(R3+R4) / (R3‑R4)|<0.9. The optical lens provided by the application has one or more advantages such as long focal length, large aperture, high imaging quality and the like through specific surface shape matching and reasonable refractive power distribution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] With the continuous improvement of people's requirements for driving experience, vehicle application type optical lenses are increasingly used in intelligent driving, and vehicle optical lenses are continuously improving in the automotive industry.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving, which collects environmental information through various lenses and sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for ADAS systems, such as light, thin, small shape and high pixel, high resolution, the optical lenses also need to be able to clearly image in low light conditions, so it is necessary to develop an optical lens with good imaging effect. SUMMARY

[0004] In view of the above problems, the purpose of the present application is to provide an optical lens with excellent imaging quality.

[0005] The technical scheme adopted by the present application is:

[0006] An optical lens, a total of seven lenses, including in order along the optical axis from the object side to the imaging surface:

[0007] a first lens with positive focal power;

[0008] a second lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0009] a third lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave;

[0010] a fourth lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0011] a fifth lens with negative focal power, the object side surface of which is concave, and the image side surface of which is convex;

[0012] a sixth lens with positive focal power, the object side surface of which is convex;

[0013] a seventh lens with negative focal power, the object side surface of which is concave;

[0014] wherein the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy: |(R3+R4) / (R3-R4)|<0.9.

[0015] It is further preferred that the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2 < TTL / f < 3; the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 4 < TTL / IH < 5.

[0016] It is further preferred that the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 15° < FOV / Fno < 20°; the real 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 < 1.2.

[0017] It is further preferred that the maximum field of view angle FOV of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 6 < d1 / (IH / 2) / tan(FOV / 2) < 8; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -37 < f123 / f4567 < -5.

[0018] It is further preferred that the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.2 < f2 / f < 10; the object side surface curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 0.9 < R3 / f < 25; the image side surface curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: -15 < R4 / f < -4.

[0019] It is further preferred that the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -1.7 < f3 / f < -0.6; the object side surface curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -2.4 < R5 / f < -0.9; the image side surface curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 0.4 < R6 / f < 2.9.

[0020] It is further preferred that the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.4 < f4 / f < 0.7; the object side surface curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R7 / f < 0.8; the image side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -0.6 < R8 / f < -0.35.

[0021] It is further preferred that the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -2.5 < f5 / f < -0.9; the object side surface curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.6 < R9 / f < -0.35; and the image side surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -1.15 < R10 / f < -0.6.

[0022] It is further preferred that the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.1 < f7 / f < -0.5; and the object side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.95 < R13 / f < -0.4.

[0023] It is further preferred that the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy: -0.5 < (R9-R10) / (R9+R10) < -0.2; the object side surface curvature radius R5 of the third lens and the image side surface curvature radius R6 of the third lens satisfy: |(R5+R6) / (R5-R6)| < 0.8; and the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0 < (R7+R8) / (R7-R8) < 0.5.

[0024] The optical lens provided by the present application adopts seven lenses with specific focal lengths, and through specific surface shape matching and reasonable focal length distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages such as long focal length, large aperture, high imaging quality, etc. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0026] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0027] Figure 2 FIG. 2 is a field curvature curve of the optical lens according to the embodiment of the present application.

[0028] Figure 3 FIG. 3 is an F-Tan(Theta) distortion curve of the optical lens according to the embodiment of the present application.

[0029] Figure 4 FIG. 4 is an MTF curve of the optical lens according to the embodiment of the present application.

[0030] Figure 5The structural schematic diagram of the optical lens in embodiment 2 of the present application.

[0031] Figure 6 The field curvature curve of the optical lens in embodiment 2 of the present application.

[0032] Figure 7 The F-Tan(Theta) distortion curve of the optical lens in embodiment 2 of the present application.

[0033] Figure 8 The MTF curve of the optical lens in embodiment 2 of the present application.

[0034] Figure 9 The structural schematic diagram of the optical lens in embodiment 3 of the present application.

[0035] Figure 10 The field curvature curve of the optical lens in embodiment 3 of the present application.

[0036] Figure 11 The F-Tan(Theta) distortion curve of the optical lens in embodiment 3 of the present application.

[0037] Figure 12 The MTF curve of the optical lens in embodiment 3 of the present application.

[0038] Figure 13 The structural schematic diagram of the optical lens in embodiment 4 of the present application.

[0039] Figure 14 The field curvature curve of the optical lens in embodiment 4 of the present application.

[0040] Figure 15 The F-Tan(Theta) distortion curve of the optical lens in embodiment 4 of the present application.

[0041] Figure 16 The MTF curve of the optical lens in embodiment 4 of the present application.

[0042] Figure 17 The structural schematic diagram of the optical lens in embodiment 5 of the present application.

[0043] Figure 18 The field curvature curve of the optical lens in embodiment 5 of the present application.

[0044] Figure 19 The F-Tan(Theta) distortion curve of the optical lens in embodiment 5 of the present application.

[0045] Figure 20 The MTF curve of the optical lens in embodiment 5 of the present application.

[0046] Figure 21A structure diagram of an optical lens in Embodiment 6 of the present application.

[0047] Figure 22 A field curvature curve of the optical lens in Embodiment 6 of the present application.

[0048] Figure 23 An F-Tan(Theta) distortion curve of the optical lens in Embodiment 6 of the present application.

[0049] Figure 24 An MTF curve of the optical lens in Embodiment 6 of the present application.

[0050] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0051] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these detailed descriptions are only descriptions of embodiments of the present application and are not intended in any way to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0052] It is to be noted that, in the present specification, the expressions first, second, third and the like are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0053] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for the sake of explanation. Specifically, the shape of the spherical surface or the aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0054] In the present specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0055] It should also be understood that the words "comprise," "comprising," "include," "including," and / or "has," "having," when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. Furthermore, when describing the embodiments of the present application, the use of "or" means "and / or" unless strictly stated otherwise. Moreover, the use of "a" or "an" means "one or more" unless strictly stated otherwise. Additionally, the use of "an exemplary embodiment" or "one exemplary embodiment" means that a particular feature, structure, or result can be included in a non- limiting example of an embodiment. Furthermore, the words "example" and / or "exemplary" are used to mean serving as an example, instance, or illustration. Any aspect given as an example is not necessarily to be construed as preferred or advantageous over other aspects.

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

[0057] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0058] The optical lens provided by the embodiment of the present application is composed of seven lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface as the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens.

[0059] In some embodiments, the first lens can have a positive focal power, the object side surface thereof can be a concave surface or a convex surface, and the image side surface thereof can be a concave surface or a convex surface. The second lens can have a positive focal power, the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface. The third lens can have a negative focal power, the object side surface thereof is a concave surface, and the image side surface thereof is a concave surface. The fourth lens can have a positive focal power, the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface. The fifth lens can have a negative focal power, the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface. The sixth lens can have a positive focal power, the object side surface thereof is a convex surface, and the image side surface thereof can be a concave surface or a convex surface. The seventh lens can have a negative focal power, the object side surface thereof is a concave surface, and the image side surface thereof can be a concave surface or a convex surface.

[0060] In some embodiments, the optical lens can further include a diaphragm, which can be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of light to change the brightness of the imaging. In addition, when the diaphragm is located between the third lens and the fourth lens, the diaphragm can reasonably distribute the functions of the first lens to the seventh lens, for example, the first lens, the second lens, and the third lens can be used to receive light to a greater extent, and the fourth lens to the seventh lens can be used to correct aberrations, which is conducive to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the third lens and the fourth lens, the diaphragm aberration correction is facilitated.

[0061] In some embodiments, the optical lens can further include a filter and a protective glass, which can be sequentially arranged between the seventh lens and the imaging surface along the optical axis. The filter is used to filter out interference light to prevent interference light from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the impact resistance and scratch resistance of the optical lens, while having little effect on the imaging quality of the optical lens.

[0062] In some embodiments, the fourth lens and the fifth lens can be glued to form a glued 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; can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0063] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: |(R3+R4) / (R3-R4)|<0.9. Satisfying the above range further converges the light, which can share the positive focal power of the front end of the optical lens, thereby being conducive to avoiding excessive deflection of light caused by excessive concentration of the focal power of the first lens, and reducing the correction difficulty of aberration. More specifically, -0.79<(R3+R4) / (R3-R4)<0.54.

[0064] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2<TTL / f<3. Satisfying the above range can effectively limit the length of the lens, which is conducive to realizing the miniaturization of the optical lens. More specifically, 2.26<TTL / f<2.81.

[0065] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 4 < TTL / IH < 5. Meeting the above range ensures that, with the same total length of the lens, it has a larger image plane, can match an imaging chip of a larger size to achieve high-definition imaging, and better achieves the balance between the small total length and the large image plane of the lens. More specifically, 4.38 < TTL / IH < 4.75.

[0066] In some embodiments, the maximum field angle of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 15° < FOV / Fno < 20°. Meeting the above range limits that the optical lens has an appropriate field angle of view and aperture value, can collect light at a large angle, and obtain good imaging quality. More specifically, 15.78° < FOV / Fno < 18.83°.

[0067] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.2. Meeting the above range can increase the width of the light beam entering the optical lens, improve the brightness at the image plane of the optical lens, and avoid the generation of vignetting. More specifically, 0.92 < IH / EPD < 1.13.

[0068] 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 angle of view of the optical lens, and the maximum field angle of view FOV of the optical lens satisfy: 6 < d1 / (IH / 2) / tan(FOV / 2) < 8. Meeting the above range can have a small front aperture while meeting the requirements of the optical lens having a large field angle of view and a large image plane. More specifically, 6.3 < d1 / (IH / 2) / tan(FOV / 2) < 7.62.

[0069] In some embodiments, the combined focal length f123 of the first lens, the second lens, and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens satisfy: -37 < f123 / f4567 < -5. Meeting the above range is conducive to balancing various aberrations of the system and improving the overall imaging quality by reasonably setting the focal length relationship of the lens groups before and after the aperture. More specifically, -33.93 < f123 / f4567 < -5.29.

[0070] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.2 < f2 / f < 10; the object-side surface curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 0.9 < R3 / f < 25; and the image-side surface curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: -15 < R4 / f < -4. Satisfying the above ranges, the second lens has appropriate positive refractive power and suitable surface shape, further converges light rays, and can share the positive refractive power of the front end of the optical lens, thereby helping to avoid excessive deflection of light rays due to the too concentrated refractive power of the first lens, and reducing the correction difficulty of aberration. More specifically, 1.28 < f2 / f < 9.32; 0.95 < R3 / f < 22.84; and -14.27 < R4 / f < -4.21.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -1.7 < f3 / f < -0.6; the object-side surface curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: -2.4 < R5 / f < -0.9; the image-side surface curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 0.4 < R6 / f < 2.9; and the object-side surface curvature radius R5 of the third lens and the image-side surface curvature radius R6 of the third lens satisfy: |(R5+R6) / (R5-R6)| < 0.8. Satisfying the above ranges, the third lens has negative refractive power and a double-concave surface shape, has the effect of diverging light rays, can disperse the central light rays and the edge light rays of each field of view, and can correct the aberration generated by the front end lens. More specifically, -1.55 < f3 / f < -0.62; -2.22 < R5 / f < -1; 0.45 < R6 / f < 2.69; and -0.31 < (R5+R6) / (R5-R6) < 0.66.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.4 < f4 / f < 0.7; the object-side surface curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R7 / f < 0.8; the image-side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -0.6 < R8 / f < -0.35; the object-side surface curvature radius R7 of the fourth lens and the image-side surface curvature radius R8 of the fourth lens satisfy: 0 < (R7+R8) / (R7-R8) < 0.5. Satisfying the above ranges, the fourth lens is limited to have appropriate positive refractive power and surface shape, and the light rays are further converged. And the fourth lens with positive refractive power and the fifth lens with negative refractive power are cemented, which is beneficial to make the light rays enter the rear lens gently, can adjust the optical path difference between different fields of view, and improve the resolution. More specifically, 0.49 < f4 / f < 0.61; 0.64 < R7 / f < 0.74; 0.07 < (R7+R8) / (R7-R8) < 0.35.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -2.5 < f5 / f < -0.9; the object-side surface curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.6 < R9 / f < -0.35; the image-side surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -1.15 < R10 / f < -0.6; the object-side surface curvature radius R9 of the fifth lens and the image-side surface curvature radius R10 of the fifth lens satisfy: -0.5 < (R9-R10) / (R9+R10) < -0.2. Satisfying the above ranges, the fifth lens is limited to have appropriate negative refractive power and surface shape, and the light rays emitted by the fourth lens can be diverged, so that the light rays of the edge field have an upward trend, which is beneficial to make the image points on the imaging surface away from the optical axis, so as to realize the effect of matching with a large chip, obtain a larger picture, effectively eliminate aberration, and improve the resolution of the optical lens. More specifically, -2.28 < f5 / f < -0.97; -1.08 < R10 / f < -0.68; -0.43 < (R9-R10) / (R9+R10) < -0.22.

[0074] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -1.1 < f7 / f < -0.5; the object-side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.95 < R13 / f < -0.4. Satisfying the above ranges, various aberrations generated by the front lens group can be effectively balanced, and at the same time, the degree of divergence of the light rays is increased, the area of the light rays entering the imaging surface is increased, the large target surface imaging of the lens is realized, and the imaging quality of the optical lens is improved. More specifically, -0.99 < f7 / f < -0.58; -0.89 < R13 / f < -0.42.

[0075] In some embodiments, a real image height IH corresponding to a maximum field angle of the optical lens and an effective focal length f of the optical lens satisfy: 0.5 < IH / f < 0.65. Satisfying the above range, the image height and the focal length of the optical lens are controlled within a reasonable range, which helps the optical lens to have a large image surface and improves the imaging quality. More specifically, 0.51 < IH / f < 0.6.

[0076] In some embodiments, an effective focal length f of the optical lens and a back focal length BFL of the optical lens satisfy: 0.19 < BFL / f < 0.31. Satisfying the above range, the optical lens is limited to have a suitable back focus, which facilitates reasonable arrangement of positions of the lenses and reduces the difficulty of processing and assembly.

[0077] In some embodiments, a total length TTL of the optical lens and a sum ∑CT of central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.51 < ∑CT / TTL < 0.73. Satisfying the above range, the total length of the optical lens can be effectively compressed, and meanwhile the structure design and production process of the optical lens are facilitated.

[0078] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 1.19 < ∑CT / f < 1.91. Satisfying the above range, the field curvature and the distortion of the optical lens can be effectively corrected, and the imaging quality of the optical lens is improved.

[0079] In some embodiments, the effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: 1.3 < f1 / f < 60. Satisfying the above range, the first lens is set to have positive refractive power, which has the effect of converging light rays and lowering the height of peripheral light rays, and is beneficial to the reduction of the aperture of the rear-end lens. More specifically, 1.47 < f1 / f < 57.19.

[0080] In some embodiments, a focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.6 < f6 / f < 3.9; and a curvature radius R11 of an object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.7 < R11 / f < 1.4. Satisfying the above range, the sixth lens is limited to have positive refractive power and the object side surface is a convex surface, which is beneficial to the convergence of light rays, makes the light ray trend smoothly transition to the rear, reduces the height of the light rays incident to the rear, slows down the upward trend of the light rays, avoids the light energy loss caused by the too large angle between the main light ray and the chip when the large field angle light ray reaches the imaging surface, is beneficial to improve the illumination of the edge field, and is beneficial to realize a short total optical length. More specifically, 0.66 < f6 / f < 3.57; and 0.77 < R11 / f < 1.27.

[0081] In some embodiments, the optical lens satisfies the following conditional expressions: 12 mm < f < 16 mm; 6.5 mm < EPD < 8.5 mm; 33 mm < TTL < 37 mm; 1.6 < Fno < 2; 16° < CRA < 26°; 3 mm < BFL < 4.3 mm; 29° < FOV < 35°; 7 mm < IH < 8 mm. In the above conditional expressions, f represents the effective focal length 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, CRA represents the chief ray angle of incidence of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle 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, 12.87 mm < f < 14.99 mm; 6.77 mm < EPD < 8.18 mm; 33.7 mm < TTL < 36.1 mm; 1.69 < Fno < 1.91; 16.25° < CRA < 25.12°; 3.03 mm < BFL < 4.22 mm; 29.9° < FOV < 34.1°; 7.59 mm < IH < 7.76 mm.

[0082] 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, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

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

[0084] 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.

[0085] Example 1

[0086] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0087] Among them, the first lens L1 has positive optical power, its object side S1 is convex, and its image side S2 is concave.

[0088] The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is convex.

[0089] The third lens L3 has negative optical power, its object side S5 is concave, and its image side S6 is concave.

[0090] The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side is convex.

[0091] The fifth lens L5 has negative optical power, its object side is concave, and its image side S9 is convex.

[0092] The fourth lens L4 and the fifth lens L5 form a cemented lens group with positive optical power, 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.

[0093] The sixth lens L6 has positive optical power, its object side S10 is convex, and its image side S11 is concave.

[0094] The seventh lens L7 has negative optical power, its object side S12 is concave, and its image side S13 is concave.

[0095] The object-side surface S14 and the image-side surface S15 of filter G1 are both planar.

[0096] The object side S16 and the image side S17 of the protective glass G2 are both flat.

[0097] The imaging plane S18 is a plane.

[0098] 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 are glass spherical lenses.

[0099] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1.

[0100] Table 1

[0101]

[0102] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 100 are shown in FIGS. 1-3, respectively. Figure 2 、 Figure 3 、 Figure 4

[0103] Figure 2 The field curvature curve of the embodiment 1 is shown in FIG. 1, which represents the curvature degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.01mm-0.05mm, which indicates that the optical lens can well correct the field curvature.

[0104] Figure 3 The F-Tan(Theta) distortion curve of the embodiment 1 is shown in FIG. 2, which represents the F-Tan(Theta) distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tan(Theta) distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tan(Theta) distortion of the optical lens is controlled within -6%-0, which indicates that the optical lens can well correct the distortion.

[0105] Figure 4 The MTF (Modulation Transfer Function) curve of the embodiment 1 is shown in FIG. 3, which represents the imaging modulation degree of the lens 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. As can be seen from the figure, the MTF value of the embodiment is above 0.4 within the full field of view, and in the range of 0-120 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge field of view, which has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0106] Embodiment 2

[0107] Please refer to FIG. 4, which shows the structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the present application, and the main difference between the embodiment and the embodiment 1 is that the image side surface S11 of the sixth lens L6 is a convex surface, and the optical parameters such as the curvature radius and the lens thickness of each lens surface are different. Figure 5 The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2.

[0108] Table 2

[0109]

[0110] ​​

[0111] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 200 are shown in Figure 6 , Figure 7 , Figure 8 respectively. As can be seen from Figure 6 , the field curvature of the meridional image surface and the sagittal image surface is controlled within 0-0.05 mm, which indicates that the optical lens can correct the field curvature well. As can be seen from Figure 7 , the F-Tan(Theta) distortion of the optical lens is controlled within-5%-0, which indicates that the optical lens can correct the distortion well. As can be seen from Figure 8 , the MTF value of the embodiment is above 0.38 in the full field of view, and the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0-120 lp / mm, which has good imaging quality and good detail resolution ability in the low frequency and high frequency conditions.

[0112] Embodiment 3

[0113] Please refer to Figure 9 , which is a structural schematic diagram of the optical lens 300 provided in the embodiment 3 of the present application. Compared with the embodiment 1, the main difference is that the image side surface S13 of the seventh lens L7 is a convex surface, and the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0114] The related parameters of each lens in the optical lens 300 in the embodiment 3 are shown in Table 3.

[0115] Table 3

[0116]

[0117] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 300 are shown in Figure 10 , Figure 11 , Figure 12 respectively. As can be seen from Figure 10 , the field curvature of the meridional image surface and the sagittal image surface is controlled within 0-0.05 mm, which indicates that the optical lens can correct the field curvature well. As can be seen from Figure 11 , the F-Tan(Theta) distortion of the optical lens is controlled within-4%-0, which indicates that the optical lens can correct the distortion well. As can be seen from Figure 12As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0118] Example 4

[0119] Please see Figure 13 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S2 of the first lens L1 is a convex surface; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0120] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4.

[0121] Table 4

[0122]

[0123] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, and MTF curve of the optical lens 400 are respectively as follows: Figure 14 , Figure 15 , Figure 16 As shown. From Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0.05mm, indicating that the optical lens can effectively correct field curvature. From Figure 15 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -0.5% to 0, indicating that the optical lens can effectively correct distortion. From Figure 16 As can be seen, the MTF value of this embodiment is above 0.3 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0124] Example 5

[0125] Please see Figure 17 The figure shows a schematic diagram of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object side S1 of the first lens L1 is concave; the image side S2 of the first lens L1 is convex; the image side S13 of the seventh lens L7 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0126] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5.

[0127] Table 5

[0128]

[0129] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 500 are shown in Figure 18 , Figure 19 , Figure 20 respectively. As can be seen from Figure 18 , the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.04mm~0.05mm, which indicates that the optical lens can correct the field curvature well. As can be seen from Figure 19 , the F-Tan(Theta) distortion of the optical lens is controlled within -4%~0, which indicates that the optical lens can correct the distortion well. As can be seen from Figure 20 , the MTF value of the embodiment is above 0.3 in the full field of view, and the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0~120lp / mm, which has good imaging quality and good detail resolution ability in the low frequency and high frequency conditions.

[0130] Embodiment 6

[0131] Please refer to Figure 21 , which is a structural schematic diagram of the optical lens 600 provided in the embodiment 6 of the present application. Compared with the embodiment 1, the main difference is that: the object side S1 of the first lens L1 is a concave surface; the image side S2 of the first lens L1 is a convex surface; the image side S11 of the sixth lens L6 is a convex surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0132] The related parameters of each lens in the optical lens 600 in the embodiment 6 are shown in Table 6.

[0133] Table 6

[0134]

[0135] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 600 are shown in Figure 22 , Figure 23 , Figure 24 respectively. As can be seen from Figure 22 , the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.02mm~0.04mm, which indicates that the optical lens can correct the field curvature well. As can be seen from Figure 23 , the F-Tan(Theta) distortion of the optical lens is controlled within -3%~0, which indicates that the optical lens can correct the distortion well. As can be seen fromFigure 24 It can be seen that the MTF value of the embodiment is above 0.3 in the full field of view, and in the range of 0-120 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution in the case of low frequency and high frequency.

[0136] Referring to Table 7, the optical characteristics corresponding to the above embodiments are shown, including the effective focal length f, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view, the maximum field of view FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0137] Table 7

[0138]

[0139]

[0140] In summary, the optical lens provided by the present application adopts seven lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages such as long focal length, large aperture, high imaging quality, etc.

[0141] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0142] The above-described embodiments only express several embodiments of the present application, which are described in detail and specifically, but should not be understood as limiting the scope of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. An optical lens comprising seven lenses, characterized in that, It sequentially includes, from the object side to the imaging surface along the optical axis: A first lens with positive optical power; A second lens with positive optical power, whose object side surface is convex and whose image side surface is convex; A third lens with negative optical power, whose object side surface is concave and whose image side surface is concave; A fourth lens with positive optical power, whose object side surface is convex and whose image side surface is convex; A fifth lens with negative optical power, whose object side surface is concave and whose image side surface is convex; A sixth lens with positive optical power, whose object side surface is convex; A seventh lens with negative optical power, whose object side surface is concave; Wherein, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface of the second lens satisfy: |(R3 + R4) / (R3 - R4)| < 0.9; the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2 < TTL / f < 3; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 4 < TTL / IH < 5.

2. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 15° < FOV / Fno < 20°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9 < IH / EPD < 1.

2.

3. The optical lens according to claim 1, characterized in that, The clear aperture radius d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 6 < d1 / (IH / 2) / tan(FOV / 2) < 8; the combined focal length f123 of the first lens, the second lens and the third lens and the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens satisfy: -37 < f123 / f4567 < -5.

4. The optical lens according to claim 1, characterized in that, The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.2 < f2 / f < 10; the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.9 < R3 / f < 25; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: -15 < R4 / f < -4.

5. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -1.7 < f3 / f < -0.6; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: -2.4 < R5 / f < -0.9; the radius of curvature R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 0.4 < R6 / f < 2.

9.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.4 < f4 / f < 0.7; 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 < 0.8; 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: -0.6 < R8 / f < -0.

35.

7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -2.5 < f5 / f < -0.9; the object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.6 < R9 / f < -0.35; the image-side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -1.15 < R10 / f < -0.

6.

8. 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: -1.1 < f7 / f < -0.5; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.95 < R13 / f < -0.

4.

9. The optical lens according to claim 1, characterized in that, The object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: -0.5 < (R9 - R10) / (R9 + R10) < -0.2; the object-side curvature radius R5 of the third lens and the image-side curvature radius R6 of the third lens satisfy: |(R5 + R6) / (R5 - R6)| < 0.8; the object-side curvature radius R7 of the fourth lens and the image-side curvature radius R8 of the fourth lens satisfy: 0 < (R7 + R8) / (R7 - R8) < 0.5.

Images