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 the seven lenses comprise: a first lens with negative optical power, wherein the object side surface of the first lens is a concave surface, and the image side surface of the first lens is a convex surface; a second lens with positive optical power, wherein the object side surface and the image side surface of the second lens are both convex surfaces; a third lens with positive optical power, wherein the image side surface of the third lens is a convex surface; a fourth lens with negative optical power, wherein the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; a fifth lens with positive optical power, wherein the object side surface and the image side surface of the fifth lens are both convex surfaces; a sixth lens with positive optical power, wherein the object side surface of the sixth lens is a convex surface; and a seventh lens with negative optical power, wherein the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a concave surface; 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: -1.5<(R7+R8) / (R7-R8)<-1.33. The optical lens provided by the application has one or more advantages of long focal length, large aperture, high imaging quality and the like through specific surface shape matching and reasonable optical power distribution.

Description

Technical Field

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

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS lenses not only require a slim and compact design with high pixel count and high resolution, but also need to produce clear images in low-light conditions. Therefore, it is necessary to develop an optical lens with excellent imaging performance. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0005] The technical solution adopted in this invention is as follows:

[0006] An optical lens comprises seven lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0007] The first lens with negative optical power has a concave object side and a convex image side.

[0008] A second lens with positive optical power has convex surfaces on both its object-side and image-side surfaces.

[0009] The third lens with positive optical power has a convex image-side surface;

[0010] The fourth lens with negative optical power has a concave object side and a convex image side.

[0011] The fifth lens with positive optical power has convex surfaces on both its object side and image side.

[0012] The sixth lens has positive optical power and its object side is convex.

[0013] The seventh lens with negative optical power has a concave object side and a concave image side.

[0014] Wherein, the object-side radius of curvature R7 of the fourth lens and the image-side radius of curvature R8 of the fourth lens satisfy: -1.5<(R7+R8) / (R7-R8)<-1.33.

[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: 2.4 < TTL / f < 2.7; 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: 4.6 < TTL / IH < 5.

[0016] It is further preferred that the real 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: 0.95 < (IH / 2) / (f x Tan(FOV / 2)) < 0.98; the total track length TTL of the optical lens, the real 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: 0.59 / ° < TTL / (IH / 2) / (FOV / 2) < 0.64 / °.

[0017] It is further preferred that the real 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: 0.52 < IH / f < 0.55; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.25 < BFL / f < 0.29.

[0018] It is further preferred that the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2 < f1 / f < -1.1; the object side surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: -0.9 < R1 / f < -0.75; the image side surface curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: -10 < R2 / f < -2.5.

[0019] It is further preferred that the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.15 < f4 / f < -0.85; the object side surface curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -0.88 < R7 / f < -0.65; the image side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -6 < R8 / f < -3.3.

[0020] It is further preferred that the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.2 < f5 / f < 1.45; the object side surface curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < R9 / f < 0.9; the image side surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -3.7 < R10 / f < -2.7.

[0021] It is further preferred that the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -0.7 < f7 / f < -0.55; the object side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.9 < R13 / f < -0.5; and the image side surface curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.8 < R14 / f < 12.

[0022] It is further preferred 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 < 3.6.

[0023] It is further preferred that the object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: -0.85 < (R1-R2) / (R1+R2) < -0.51; and the object side surface curvature radius R13 of the seventh lens and the image side surface curvature radius R14 of the seventh lens satisfy: -0.92 < (R13+R14) / (R13-R14) < -0.02.

[0024] It is further preferred that the object side surface half-field radius d7 of the fourth lens and the object side surface half-field radius sag7 of the fourth lens satisfy: -0.29 < sag7 / d7 < -0.23; and the image side surface half-field radius d8 of the fourth lens and the image side surface half-field radius sag8 of the fourth lens satisfy: -0.06 < sag8 / d8 < -0.02.

[0025] 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 and the like. BRIEF DESCRIPTION OF DRAWINGS

[0026] 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:

[0027] Figure 1 FIG. 1 is a structure diagram of an optical lens according to an embodiment of the present application.

[0028] Figure 2 FIG. 2 is a field curvature curve of the optical lens according to the embodiment of the present application.

[0029] Figure 3 FIG. 3 is an F-Tan(Theta) distortion curve of the optical lens according to the embodiment of the present application.

[0030] Figure 4 Axial aberration curve of the optical lens in Embodiment 1 of the present application.

[0031] Figure 5 Decentration curve of the optical lens in Embodiment 1 of the present application.

[0032] Figure 6 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0033] Figure 7 Curvature of field curve of the optical lens in Embodiment 2 of the present application.

[0034] Figure 8 F-Tan(Theta) distortion curve of the optical lens in Embodiment 2 of the present application.

[0035] Figure 9 Axial aberration curve of the optical lens in Embodiment 2 of the present application.

[0036] Figure 10 Decentration curve of the optical lens in Embodiment 2 of the present application.

[0037] Figure 11 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0038] Figure 12 Curvature of field curve of the optical lens in Embodiment 3 of the present application.

[0039] Figure 13 F-Tan(Theta) distortion curve of the optical lens in Embodiment 3 of the present application.

[0040] Figure 14 Axial aberration curve of the optical lens in Embodiment 3 of the present application.

[0041] Figure 15 Decentration curve of the optical lens in Embodiment 3 of the present application.

[0042] Figure 16 Structure diagram of the optical lens in Embodiment 4 of the present application.

[0043] Figure 17 Curvature of field curve of the optical lens in Embodiment 4 of the present application.

[0044] Figure 18 F-Tan(Theta) distortion curve of the optical lens in Embodiment 4 of the present application.

[0045] Figure 19 Axial aberration curve of the optical lens in Embodiment 4 of the present application.

[0046] Figure 20 A curve graph of the optical lens of the present application in embodiment 4 is shown in FIG. 4.

[0047] Figure 21 A structure diagram of the optical lens of the present application in embodiment 5 is shown in FIG. 5.

[0048] Figure 22 A curve graph of the field curvature of the optical lens of the present application in embodiment 5 is shown in FIG. 6.

[0049] Figure 23 An F-Tan(Theta) distortion curve of the optical lens of the present application in embodiment 5 is shown in FIG. 7.

[0050] Figure 24 An axial aberration curve graph of the optical lens of the present application in embodiment 5 is shown in FIG. 8.

[0051] Figure 25 A curve graph of the optical lens of the present application in embodiment 5 is shown in FIG. 4.

[0052] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0053] 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.

[0054] 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 of the features. Thus, the first lens discussed below can also be referred to as a second lens or a third lens without departing from the teachings of the present application.

[0055] 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 or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0056] In the present disclosure, 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.

[0057] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", 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. In addition, when describing the embodiments of the present application, the use of "may" means that one or more embodiments of the present application. Also, the word "exemplary" is intended to mean an example or an illustration.

[0058] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms 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 idealized or overly formal sense unless expressly so defined herein.

[0059] It should be noted that the embodiments in the present application and the features in the embodiments 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 the embodiments.

[0060] The optical lens provided by the embodiments of the present application is composed of seven lenses, which are sequentially arranged along the optical axis from the object side to the image plane as the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens.

[0061] In some embodiments, the first lens can have a negative focal power, the object side surface thereof is concave, and the image side surface thereof is convex. The second lens can have a positive focal power, and both the object side surface and the image side surface thereof are convex. The third lens can have a positive focal power, the object side surface thereof can be concave or convex, and the image side surface thereof is convex. The fourth lens can have a negative focal power, the object side surface thereof is concave, and the image side surface thereof is convex. The fifth lens can have a positive focal power, and both the object side surface and the image side surface thereof are convex. The sixth lens can have a positive focal power, the object side surface thereof is convex, and the image side surface thereof can be concave or convex. The seventh lens can have a negative focal power, the object side surface thereof is concave, and the image side surface thereof is concave.

[0062] In some embodiments, the optical lens can further include a diaphragm, which can be located between the fourth lens and the fifth 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 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 greater extent, and the fifth lens to the seventh lens can be used for the function of correcting aberration, which is conducive to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the fourth lens and the fifth lens, the correction of the diaphragm aberration is facilitated.

[0063] In some embodiments, the optical lens can further include a filter and a protective glass, which can be sequentially arranged along the optical axis between the seventh lens and the imaging surface. 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.

[0064] In some embodiments, the third lens and the fourth lens can be glued to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentric 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.

[0065] In some embodiments, the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -1.5<(R7+R8) / (R7-R8)<-1.33. Satisfying the above range is conducive to converging the light rays passing through the third lens, balancing the aberration of the optical lens, and improving the imaging quality of the optical lens.

[0066] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.4<TTL / f<2.7. Satisfying the above range can effectively limit the length of the lens while realizing long focus, which is conducive to realizing the miniaturization of the optical lens. More specifically, 2.48<TTL / f<2.62.

[0067] In some embodiments, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 4.6<TTL / IH<5. Satisfying the above range ensures that the lens has a larger image surface under the condition of the same total length, which can match a larger size imaging chip to realize high-definition imaging, and better realize the balance between the small total length and the large image surface of the lens. More specifically, 4.6<TTL / IH<4.93.

[0068] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.95 < (IH / 2) / (f x Tan(FOV / 2)) < 0.98. Satisfying the above range, the optical lens can be controlled to have smaller distortion, and the imaging quality is improved.

[0069] In some embodiments, 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: 0.59 / ° < TTL / (IH / 2) / (FOV / 2) < 0.64 / °. Satisfying the above range, the length of the optical lens is limited in the case of the same imaging area and the same field of view, and the optical lens is miniaturized.

[0070] In some embodiments, the real image height IH corresponding to the maximum field of view of the optical lens, and the effective focal length f of the optical lens satisfy: 0.52 < IH / f < 0.55. Satisfying the above range, the image height and the focal length of the optical lens are controlled to be within a reasonable range, which helps the optical lens to have a large image surface and improve the imaging quality.

[0071] In some embodiments, the effective focal length f of the optical lens, and the back focal length BFL of the optical lens satisfy: 0.25 < BFL / f < 0.29. Satisfying the above range, the optical lens is limited to have a suitable back focus, which facilitates the reasonable arrangement of the positions of the lenses and reduces the difficulty of processing and assembly.

[0072] In some embodiments, the effective focal length f of the optical lens, and the focal length f1 of the first lens satisfy: -2 < f1 / f < -1.1; the object side surface curvature radius R1 of the first lens, and the effective focal length f of the optical lens satisfy: -0.9 < R1 / f < -0.75; the image side surface curvature radius R2 of the first lens, and the effective focal length f of the optical lens satisfy: -10 < R2 / f < -2.5. Satisfying the above range, by setting the first lens to have negative refractive power and a suitable surface shape, the first lens can accommodate light rays of a larger angle and collect as much light as possible into the rear optical system, realizing a large field of view while increasing the luminous flux. More specifically, -1.99 < f1 / f < -1.14; -0.86 < R1 / f < -0.78; -9.57 < R2 / f < -2.52.

[0073] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.15 < f4 / f < -0.85; the object-side surface curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -0.88 < R7 / f < -0.65; and the image-side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -6 < R8 / f < -3.3. Satisfying the above ranges, the fourth lens is limited to have appropriate negative refractive power and a suitable surface shape, which can diverge the light rays emitted by the third lens, and make the light rays of the edge field have an upward trend, so as to facilitate the image points on the imaging surface to be away from the optical axis, thereby facilitating the realization of the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolving power of the optical lens. More specifically, -1.11 < f4 / f < -0.88; and -6 < R8 / f < -3.36.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.2 < f5 / f < 1.45; the object-side surface curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < R9 / f < 0.9; and the image-side surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -3.7 < R10 / f < -2.7. Satisfying the above ranges, the fifth lens is set to have positive refractive power and a suitable surface shape, which is beneficial to converging light rays while correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens. More specifically, 1.2 < f5 / f < 1.42; 0.71 < R9 / f < 0.88; and -3.61 < R10 / f < -2.75.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -0.7 < f7 / f < -0.55; the object-side surface curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: -0.9 < R13 / f < -0.5; and the image-side surface curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.8 < R14 / f < 12. Satisfying the above ranges, various aberrations generated by the front lens group can be effectively balanced, while it is beneficial to increase the divergence degree of light rays, increase the area of light rays entering the imaging surface, realize large target surface imaging of the lens, and improve the imaging quality of the optical lens. More specifically, -0.69 < f7 / f < -0.56; -0.88 < R13 / f < -0.53; and 0.84 < R14 / f < 11.62.

[0076] In some embodiments, a combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and a combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: 1.4 < f1234 / f567 < 3.6. By satisfying the above range, by reasonably setting the lens group relationship before and after the stop, the various aberrations of the system can be balanced, and the overall imaging quality can be improved. More specifically, 1.42 < f1234 / f567 < 3.58.

[0077] In some embodiments, a radius of curvature R1 of the object side surface of the first lens and a radius of curvature R2 of the image side surface of the first lens satisfy: -0.85 < (R1-R2) / (R1+R2) < -0.51. By satisfying the above range, the collected light can be made to enter the rear optical system in the form of divergence as much as possible, while effectively reducing the angle between the edge field of view light and the object side surface of the first lens when the light is incident, and improving the overall edge relative luminance of the lens.

[0078] In some embodiments, a radius of curvature R13 of the object side surface of the seventh lens and a radius of curvature R14 of the image side surface of the seventh lens satisfy: -0.92 < (R13+R14) / (R13-R14) < -0.02. By satisfying the above range, the surface type of the seventh lens is controlled, which is conducive to increasing the imaging area and the field of view angle of the optical lens, balancing the aberration of the optical lens, and improving the imaging quality of the optical lens.

[0079] In some embodiments, a half-diameter Sag7 of the object side light passing surface of the fourth lens and a half-diameter Sag8 of the image side light passing surface of the fourth lens satisfy: -0.29 < Sag7 / d7 < -0.23; and -0.06 < Sag8 / d8 < -0.02. By satisfying the above range, the trend of the edge field of view light can be controlled, and the center field of view detail information of the optical lens can be highlighted.

[0080] In some embodiments, a maximum field of view angle FOV of the optical lens and an aperture value Fno of the optical lens satisfy: 17° < FOV / Fno < 19°. By satisfying the above range, the optical lens is limited to have a suitable field of view angle and aperture value, which can collect light rays of a large angle and obtain good imaging quality. More specifically, 17.21° < FOV / Fno < 18.8°.

[0081] In some embodiments, a real image height IH corresponding to the maximum field of view angle of the optical lens and an entrance pupil diameter EPD of the optical lens satisfy: 0.85 < IH / EPD < 1. By satisfying the above range, the width of the light beam entering the optical lens can be increased, so that the brightness of the optical lens at the image plane is improved to avoid dark corners. More specifically, 0.86 < IH / EPD < 0.97.

[0082] In some embodiments, the total track 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 respectively satisfy: 0.61<∑CT / TTL<0.67. Satisfying the above range, the total length of the optical lens can be effectively compressed, and meanwhile the structural design and production process of the optical lens are facilitated.

[0083] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.2<f2 / f<1.35; the object-side surface curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 2.1<R3 / f<4.2; and the image-side surface curvature radius R2 of the second lens and the effective focal length f of the optical lens satisfy: -1.5<R4 / f<-1.1. Satisfying the above range, the second lens is defined to have appropriate positive refractive power and suitable surface shape, has the effect of converging light rays, and lowers the height of peripheral light rays, which is beneficial to the reduction of the aperture of the rear lens, and meanwhile facilitates the balancing of aberrations and improves resolution. More specifically, 1.2<f2 / f<1.31; 2.11<R3 / f<4.18; and -1.47<R4 / f<-1.1.

[0084] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.05<f3 / f<1.2; and the image-side surface curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: -0.88<R6 / f<-0.65. Satisfying the above range, the third lens is defined to have appropriate positive refractive power and suitable surface shape, and light rays are further converged. The third lens with positive refractive power and the fourth lens with negative refractive power are cemented, which is beneficial to making light rays enter the rear lens gently, can adjust the optical path difference between different fields of view, and improves resolution. More specifically, 1.07<f3 / f<1.16.

[0085] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 1.1<f6 / f<2.1; and the object-side surface curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 1<R11 / f<1.6. Satisfying the above range, the sixth lens is defined to have positive refractive power, which is beneficial to the convergence of light rays, makes the light ray trend transition to the rear smoothly, reduces the height of light rays incident to the rear, slows down the upward trend of light rays, avoids the loss of light energy caused by the excessively large angle between the main light ray of the chip and the light ray of the large field of view when reaching the imaging surface, is beneficial to improving the illumination of the edge field of view, and is beneficial to realizing a short total track length. More specifically, 1.15<f6 / f<2.08; and 1.07<R11 / f<1.6.

[0086] In some embodiments, the optical lens satisfies the following conditional expressions: 11mm < f < 13mm; 30° < FOV < 32°; 6mm < EPD < 8mm; 29mm < TTL < 31mm; 1.6 < Fno < 1.9; 6mm < IH < 7mm; 21° < CRA < 22°; 3.1mm < BFL < 3.3mm. 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 total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the real 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. Satisfying the above ranges, the optical lens has one or more advantages such as large target surface, large aperture, long focal length, and the like. More specifically, 11.47mm < f < 12.27mm; 6.37mm < EPD < 7.22mm; 29.99mm < TTL < 30.58mm; 1.64 < Fno < 1.81; 21.14° < CRA < 21.99°; 3.17mm < BFL < 3.23mm; 30.9° < FOV < 31.1°; 6.09mm < IH < 6.64mm.

[0087] In some embodiments, the lens material in the optical lens provided by the present application can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. 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 application can adopt a full-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0088] 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 a spherical lens or an aspherical lens. Compared with a spherical structure, an 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 achieving lens miniaturization. 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 application adopt a spherical lens.

[0089] The present application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, and the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments only, and any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement modes, and all are included in the protection scope of the present application.

[0090] Embodiment 1

[0091] Referring to Figure 1 , a structural schematic diagram of an optical lens 100 provided in Embodiment 1 of the present application is shown, which comprises, in sequence 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 stop ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0092] The first lens L1 has a negative focal power, the object side S1 thereof is a concave surface, and the image side S2 thereof is a convex surface.

[0093] The second lens L2 has a positive focal power, the object side S3 thereof is a convex surface, and the image side S4 thereof is a convex surface.

[0094] The third lens L3 has a positive focal power, the object side S5 and the image side S6 thereof are both convex surfaces.

[0095] The fourth lens L4 has a negative focal power, the object side S6 thereof is a concave surface, and the image side S7 thereof is a convex surface.

[0096] The third lens L3 and the fourth lens L4 constitute a cemented lens group with a positive focal power, i.e., the cemented surface of the image side of the third lens L3 and the object side of the fourth lens L4 is S6.

[0097] The fifth lens L5 has a positive focal power, the object side S8 thereof is a convex surface, and the image side S9 thereof is a convex surface.

[0098] The sixth lens L6 has a positive focal power, the object side S10 thereof is a convex surface, and the image side S11 thereof is a concave surface.

[0099] The seventh lens L7 has a negative focal power, the object side S12 thereof is a concave surface, and the image side S13 thereof is a concave surface.

[0100] The object side S14 and the image side S15 of the filter G1 are both flat surfaces.

[0101] The object side S16 and the image side S17 of the protective glass G2 are both flat surfaces.

[0102] The imaging surface S18 is a flat surface.

[0103] 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 all glass spherical lenses.

[0104] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1.

[0105] Table 1

[0106]

[0107]

[0108] In this embodiment, the field curvature curve, F-Tan(Theta) distortion curve, axial aberration curve and sagittal chromatic aberration curve of the optical lens 100 are shown in FIGS. 1A, 1B, 1C and 1D, respectively. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5

[0109] Figure 2 The field curvature curve of Example 1 is shown, which represents the curvature of light rays of different wavelengths on the meridional image surface and 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~0.03mm, which shows that the optical lens can well correct the field curvature.

[0110] Figure 3 The F-Tan(Theta) distortion curve of Example 1 is shown, 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 -3%~0, which shows that the optical lens can better correct the distortion.

[0111] Figure 4 The axial aberration curve of Example 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. As can be seen from the figure, the offset of the axial aberration is controlled within -0.01mm~0.03mm, which shows that the optical lens can better correct the axial aberration.

[0112] Figure 5 The sagittal chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.55μm) at different image heights on the imaging surface, the horizontal axis represents the sagittal chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. As can be seen from the figure, the sagittal chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~2μm, which shows that the optical lens can very well correct the chromatic aberration.

[0113] Example 2

[0114] Please refer to Figure 6 ​, as shown is a structural schematic view of the optical lens 200 provided in the embodiment 2 of the present application, compared with the embodiment 1, the main difference lies in that: the third lens L3 and the fourth lens L4 constitute a cemented lens group with negative focal power; the object side S5 of the third lens L3 is a concave surface; the image side S11 of the sixth lens L6 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0115] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2.

[0116] Table 2

[0117]

[0118]

[0119] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve, the axial aberration curve and the transverse chromatic aberration curve of the optical lens 200 are respectively shown in Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 .

[0120] It can be seen from Figure 7 that the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.01mm~0.05mm, which shows that the optical lens 200 can well correct the field curvature.

[0121] It can be seen from Figure 8 that the F-Tan(Theta) distortion of the optical lens 200 is controlled within-5%~0, which shows that the optical lens 200 can better correct the distortion.

[0122] It can be seen from Figure 9 that the offset of the axial aberration is controlled within-0.01mm~0.05mm, which shows that the optical lens 200 can better correct the axial aberration.

[0123] It can be seen from Figure 10 that the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within-1um~2um, which shows that the optical lens 200 can very well correct the chromatic aberration.

[0124] Embodiment 3

[0125] Please refer to Figure 11The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the third lens L3 and the fourth lens L4 form a cemented lens group with negative optical power; the object side S5 of the third lens L3 is concave; the image side S11 of the sixth lens L6 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 300 in Example 3 are shown in Table 3.

[0127] Table 3

[0128]

[0129] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0130] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.01mm to 0.05mm, indicating that the optical lens 300 can effectively correct the field curvature.

[0131] from Figure 13 As can be seen, the F-Tan (Theta) distortion of optical lens 300 is controlled within -5% to 0, indicating that optical lens 300 can correct distortion well.

[0132] from Figure 14 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.05mm, indicating that the optical lens 300 can correct axial aberration well.

[0133] from Figure 15 As can be seen, the chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 3μm, indicating that the optical lens 300 can correct chromatic aberration very well.

[0134] Example 4

[0135] Please see Figure 16 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 third lens L3 and the fourth lens L4 form a cemented lens group with negative optical power; the object side S5 of the third lens L3 is concave; the image side S11 of the sixth lens L6 is convex; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0136] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4.

[0137] Table 4

[0138]

[0139] In this embodiment, the field curvature curve, F-Tan(Theta) distortion curve, axial aberration curve and transverse chromatic aberration curve of the optical lens 400 are shown in Figure 17 、 Figure 18 、 Figure 19 、 Figure 20 respectively.

[0140] As can be seen from Figure 17 , the field curvature of the meridional image surface and the sagittal image surface is controlled within -0.01mm-0.05mm, which shows that the optical lens 400 can well correct the field curvature.

[0141] As can be seen from Figure 18 , the F-Tan(Theta) distortion of the optical lens 400 is controlled within -5%-0, which shows that the optical lens 400 can well correct the distortion.

[0142] As can be seen from Figure 19 , the offset of the axial aberration is controlled within -0.01mm-0.05mm, which shows that the optical lens 400 can well correct the axial aberration.

[0143] As can be seen from Figure 20 , the transverse chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1um-3um, which shows that the optical lens 400 can well correct the chromatic aberration.

[0144] Embodiment 5

[0145] Please refer to Figure 21 , which is a structural schematic diagram of the optical lens 500 provided in Embodiment 5 of the present application. Compared with Embodiment 1, the main difference is that the third lens L3 and the fourth lens L4 form a cemented lens group with negative focal power; the object side S5 of the third lens L3 is a concave 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.

[0146] The related parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5.

[0147] Table 5

[0148]

[0149] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 500 are respectively as follows: Figure 22 , Figure 23 , Figure 24 , Figure 25 As shown.

[0150] from Figure 22 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.01mm to 0.04mm, indicating that the optical lens 500 can effectively correct the field curvature.

[0151] from Figure 23 As can be seen, the F-Tan (Theta) distortion of the optical lens 500 is controlled within -5% to 0, indicating that the optical lens 500 can correct distortion well.

[0152] from Figure 24 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.04mm, indicating that the optical lens 500 can correct axial aberration well.

[0153] from Figure 25 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1μm to 2μm, indicating that the optical lens 500 can correct chromatic aberration very well.

[0154] Please refer to Table 6 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0155] Table 6

[0156]

[0157]

[0158] In summary, the optical lens provided by the present invention employs seven lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as telephoto, large aperture, and high imaging quality.

[0159] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0160] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but cannot be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging surface along the optical axis, successively comprises: a first 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 second lens with positive refractive power, both the object side surface and the image side surface of which are convex surfaces; a third lens with positive refractive power, the image side surface of which is a convex surface; a fourth 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 fifth lens with positive refractive power, both the object side surface and the image side surface of which are convex surfaces; a sixth lens with positive refractive power, the object side surface of which is a convex surface; a seventh 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; wherein the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: -1.5<(R7+R8) / (R7-R8)<-1.33; the total optical length TTL of the optical lens, the real image height IH corresponding to the maximum field angle of view FOV of the optical lens, and the maximum field angle of view FOV of the optical lens satisfy: 0.59 / °<TTL / (IH / 2) / (FOV / 2)<0.64 / °.

2. The optical lens of claim 1, wherein, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.4<TTL / f<2.7; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 4.6<TTL / IH<5.

3. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field angle of view of the optical lens, the effective focal length f of the optical lens, and the maximum field angle of view FOV of the optical lens satisfy: 0.95<(IH / 2) / (f×Tan(FOV / 2))<0.

98.

4. The optical lens of claim 1, wherein, The real image height IH corresponding to the maximum field angle of view of the optical lens and the effective focal length f of the optical lens satisfy: 0.52<IH / f<0.55; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.25<BFL / f<0.

29.

5. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2<f1 / f<-1.1; the object side surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: -0.9<R1 / f<-0.75; the image side surface curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: -10<R2 / f<-2.

5.

6. The optical lens of claim 1, wherein, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: -1.15<f4 / f<-0.85; the object side surface curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -0.88<R7 / f<-0.65; the image side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -6<R8 / f<-3.

3.

7. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: 1.2 < f5 / f < 1.45; a curvature radius R9 of an object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.7 < R9 / f < 0.9; a curvature radius R10 of an image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -3.7 < R10 / f < -2.

7.

8. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f7 of the seventh lens satisfy: -0.7 < f7 / f < -0.55; a curvature radius R13 of an object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -0.9 < R13 / f < -0.5; a curvature radius R14 of an image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.8 < R14 / f < 12.

9. The optical lens of claim 1, wherein, A combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and a combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: 1.4 < f1234 / f567 < 3.

6.

10. The optical lens of claim 1, wherein, A curvature radius R1 of an object side surface of the first lens and a curvature radius R2 of an image side surface of the first lens satisfy: -0.85 < (R1-R2) / (R1+R2) < -0.51; a curvature radius R13 of an object side surface of the seventh lens and a curvature radius R14 of an image side surface of the seventh lens satisfy: -0.92 < (R13+R14) / (R13-R14) < -0.

02.

11. The optical lens of claim 1, wherein, A half light entrance radius d7 of an object side surface of the fourth lens and a sag Sag7 of the half light entrance radius of the object side surface of the fourth lens satisfy: -0.29 < Sag7 / d7 < -0.23; a half light entrance radius d8 of an image side surface of the fourth lens and a sag Sag8 of the half light entrance radius of the image side surface of the fourth lens satisfy: -0.06 < Sag8 / d8 < -0.02.

Images