Optical lens

Abstract

The present invention provides an optical lens, which has a total of six lenses. Along the optical axis, from the object side to the imaging surface, it successively includes: a first lens with a positive optical power, whose object side is convex and whose image side is concave; a second lens with a positive optical power, whose object side is convex and whose image side is concave; a third lens with a positive optical power, whose object side is convex and whose image side is concave; a fourth lens with a negative optical power, whose object side is convex and whose image side is concave; a fifth lens with a positive optical power, whose object side is convex; a sixth lens with a negative optical power, whose object side is convex and whose image side is concave. The true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.4; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 12 < f2 / f < 24. The optical lens provided by the present invention has one or more advantages such as miniaturization, large image surface, and high imaging quality.

Description

Technical Field

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

[0002] In recent years, as consumers' requirements for the photography quality of smartphones have been continuously increasing. The 6P lens has been more and more widely used, not only in high-end models, but also in many mid-range and low-end mobile phones, so as to enhance their competitiveness in the mobile phone market. Although 7P / 8P and even higher configuration lenses have emerged, their total lengths are relatively long, which is not conducive to the thin and light design of mobile phones. The 6P lens still occupies the mainstream position in the market due to its cost-effectiveness and good performance.

[0003] Currently, the mainstream trend in the development of portable electronic products is towards ultra-thinness, large field of view, ultra-high definition imaging, etc., and this trend poses higher requirements for the optical lenses mounted on portable electronic products. Summary of the Invention

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

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

[0006] An optical lens, comprising a total of six lenses, which sequentially include from the object side to the imaging surface along the optical axis:

[0007] A first lens with positive optical power, whose object side is convex and whose image side is concave;

[0008] A second lens with positive optical power, whose object side is convex and whose image side is concave;

[0009] A third lens with positive optical power, whose object side is convex and whose image side is concave;

[0010] A fourth lens with negative optical power, whose object side is convex and whose image side is concave;

[0011] A fifth lens with positive optical power, whose object side is convex;

[0012] A sixth lens with negative optical power, whose object side is convex and whose image side is concave;

[0013] Wherein, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.4; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 12 < f2 / f < 24.

[0014] More preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: f3 / f > 55; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: -42 < (R5 + R6) / (R5 - R6) < -8.

[0015] More preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.8 < f5 / f < 1.2; the curvature radius R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.4 < R9 / f < 0.75.

[0016] More preferably, the combined focal length f34 of the third lens and the fourth lens and the combined focal length f56 of the fifth lens and the sixth lens satisfy: -1 < f34 / f56 < -0.6.

[0017] More preferably, the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.2 < R5 / f < 7.8; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R6 / f < 9.5.

[0018] More preferably, the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 2.3 < R7 / f < 3.6; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < R8 / f < 0.6.

[0019] More preferably, the curvature radius R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.4 < R11 / f < 2.9; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.6 < R12 / f < 0.9.

[0020] More preferably, the curvature radius R3 of the object side surface of the second lens and the focal length f2 of the second lens satisfy: 0.05 < R3 / f2 < 0.25; the curvature radius R4 of the image side surface of the second lens and the focal length f2 of the second lens satisfy: 0.1 < R4 / f2 < 0.35.

[0021] More preferably, 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: 1.2 < (R7 + R8) / (R7 - R8) < 1.7.

[0022] Further preferably, the sagittal height Sag5 of the clear aperture of the object side surface of the third lens and the clear aperture diameter d5 of the object side surface of the third lens satisfy: -0.05 < Sag5 / d5 < -0; the sagittal height Sag6 of the clear aperture of the image side surface of the third lens and the clear aperture diameter d6 of the image side surface of the third lens satisfy: -0.1 < Sag6 / d6 < -0.01.

[0023] The optical lens provided by the present invention uses six lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and make the lens have one or more advantages such as miniaturization, large image plane, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 2 is a graph of F-Tan(Theta) distortion of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 is a graph of lateral chromatic aberration of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 is a graph of axial aberration of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 6 is a graph of F-Tan(Theta) distortion of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 7 is a graph of lateral chromatic aberration of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 8 is a graph of axial aberration of the optical lens in Embodiment 2 of the present invention.

[0033] Fig. 9 is a schematic structural diagram of the optical lens in Embodiment 3 of the present invention.

[0034] Fig.10 is a graph of F-Tan(Theta) distortion of the optical lens in Embodiment 3 of the present invention.

[0035] Fig.11 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0036] Fig.12 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0037] Fig.13 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0038] Fig.14 4 is a F-Tan (Theta) distortion curve of the optical lens in Example 4 of the present invention.

[0039] Fig.15 Graph showing the vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0040] Fig.16 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0041] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0042] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0043] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0044] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0045] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0046] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0047] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0048] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The optical lens provided by the embodiment of the present invention comprises six lenses, which are a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in order from the object side to the imaging surface along the optical axis.

[0050] In some embodiments, the first lens may have positive optical power, and its object side surface may be convex, and its image side surface may be concave. The second lens may have positive optical power, and its object side surface may be convex, and its image side surface may be concave. The third lens may have positive optical power, and its object side surface may be convex, and its image side surface may be concave. The fourth lens may have negative optical power, and its object side surface may be convex, and its image side surface may be concave. The fifth lens may have positive optical power, and its object side surface may be convex, and its image side surface may be convex or concave. The sixth lens may have negative optical power, and its object side surface may be convex, and its image side surface may be concave.

[0051] In some embodiments, the optical lens may further include a diaphragm, which may be located between the object side and the first lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image.

[0052] In some embodiments, the optical lens may further include a filter, which may be disposed between the sixth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0053] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.4; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 12 < f2 / f < 24. Meeting the above conditions, by reasonably controlling the ratio of the image height to the focal length of the optical lens, the large image plane characteristic can be achieved, and the imaging quality of the optical lens can be improved. And the second lens has appropriate positive refractive power, which is beneficial to slowing down the deflection trend of light rays and promoting the miniaturization of the structure of the optical lens. More specifically: 2.26 < IH / f < 2.29; 13.75 < f2 / f < 22.64.

[0054] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: f3 / f > 55; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: -42 < (R5 + R6) / (R5 - R6) < -8. Meeting the above range, by reasonably defining the shapes of the object side surface and the image side surface of the third lens, the third lens can have an appropriate surface shape, and the aberration of the optical lens can be effectively corrected. More specifically: 55 < f3 / f < 90; -38.5 < (R5 + R6) / (R5 - R6) < -8.83.

[0055] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.8 < f5 / f < 1.2; the curvature radius R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.4 < R9 / f < 0.75. Meeting the above range can make the fifth lens have appropriate positive optical power and define the surface shape of the object side surface of the fifth lens, which can effectively balance the lens aberration and improve the imaging quality. More specifically: 0.9 < f5 / f < 1.03; 0.47 < R9 / f < 0.68.

[0056] In some embodiments, the combined focal length f34 of the third lens and the fourth lens and the combined focal length f56 of the fifth lens and the sixth lens satisfy: -1 < f34 / f56 < -0.6. Meeting the above conditions can control the magnitudes of f34 and f56, thereby enabling the balance of the system spherical aberration and allowing the on-axis field of view to have relatively good imaging quality. More specifically: -0.83 < f34 / f56 < -0.72.

[0057] In some embodiments, the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.2 < R5 / f < 7.8; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R6 / f < 9.5. Meeting the above ranges, by reasonably setting the surface shape of the third lens, the light entering the third lens can have appropriate incident and exit angles, which is beneficial to increasing the field of view angle of the lens while reducing the outer diameter of the lens and maintaining the miniaturization of the head of the system. More specifically: 2.41 < R5 / f < 7.09; 2.54 < R6 / f < 8.89.

[0058] In some embodiments, the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 2.3 < R7 / f < 3.6; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < R8 / f < 0.6. Meeting the above ranges, by reasonably setting the surface shape of the fourth lens, it is beneficial to obtain a wider field of view without changing the physical size of the lens. More specifically: 2.62 < R7 / f < 3.28; 0.52 < R8 / f < 0.55.

[0059] In some embodiments, the curvature radius R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 1.4 < R11 / f < 2.9; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.6 < R12 / f < 0.9. Meeting the above ranges, by reasonably setting the surface shape of the sixth lens, the imaging quality of the optical system can be improved, making the image more real and natural. More specifically: 1.54 < R11 / f < 2.67; 0.72 < R12 / f < 0.79.

[0060] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the focal length f2 of the second lens satisfy: 0.05 < R3 / f2 < 0.25; the curvature radius R4 of the image side surface of the second lens and the focal length f2 of the second lens satisfy: 0.1 < R4 / f2 < 0.35. Meeting the above ranges, by reasonably setting the surface shape of the second lens, spherical aberration and coma can be effectively reduced, improving the clarity and sharpness of imaging. More specifically: 0.1 < R3 / f2 < 0.21; 0.12 < R4 / f2 < 0.3.

[0061] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 1.2 < (R7 + R8) / (R7 - R8) < 1.7. By satisfying the above range and controlling the shapes of the object side surface and the image side surface of the fourth lens, it is possible to control the fourth lens to have an appropriate surface shape, effectively improve the field curvature and aberration, and enhance the imaging quality. More specifically: 1.37 < (R7 + R8) / (R7 - R8) < 1.51.

[0062] In some embodiments, the sagittal height Sag5 of the clear aperture of the object side surface of the third lens and the clear aperture d5 of the object side surface of the third lens satisfy: -0.05 < Sag5 / d5 < -0; the sagittal height Sag6 of the clear aperture of the image side surface of the third lens and the clear aperture d6 of the image side surface of the third lens satisfy: -0.1 < Sag6 / d6 < -0.01. By satisfying the above range, it helps to control the light ray trend and highlight the detailed information of the central field of view of the optical lens. More specifically: -0.04 < Sag5 / d5 < -0.01; -0.07 < Sag6 / d6 < -0.02.

[0063] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1 < TTL / f < 1.2. By satisfying the above range, the length of the lens can be effectively limited, which is beneficial to reducing the volume of the optical lens. More specifically: 1.12 < TTL / f < 1.15.

[0064] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.25 < BFL / f < 0.3. By satisfying the above conditions, it is beneficial to reduce the volume of the optical lens and is also beneficial to reducing the interference between the lens and the imaging chip, thereby improving the assembly yield. More specifically: 0.27 < BFL / f < 0.3.

[0065] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 0.9 < f1 / f < 1.1. By satisfying the above conditions, it is beneficial to balance the spherical aberration, making the axial aberration smaller and enabling good imaging quality. More specifically: 0.96 < f1 / f < 1.03.

[0066] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: -1.1 < f4 / f < -0.8. By satisfying the above conditions, the degree of deflection of the light rays from the third lens is reduced, making the light ray trend stable and balancing the aberration generated by the front-end lens. More specifically: -1.01 < f4 / f < -0.94.

[0067] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -2.9 < f6 / f < -1.9. Meeting the above conditions is beneficial to increasing the imaging area of the optical lens and improving the imaging quality. More specifically: -2.78 < f6 / f < -2.09.

[0068] In some embodiments, 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: 2.2 < R3 / f < 3.8; 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: 2.7 < R4 / f < 5.1. Meeting the above ranges, by reasonably setting the surface shape of the second lens, the light passing through the second lens can be better focused, reducing aberration and distortion. More specifically: 2.43 < R3 / f < 3.52; 3.01 < R4 / f < 4.71.

[0069] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: 0.1 < f2 / f3 < 0.4. Meeting the above ranges, the second lens and the third lens can work together, which is beneficial to controlling the convergence of light, making the light focus more accurately on the imaging surface when passing through the optical system. More specifically: 0.15 < f2 / f3 < 0.37.

[0070] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.7 < R5 / R6 < 1. Meeting the above ranges, by reasonably setting the surface shape of the third lens, various aberrations of the optical lens are balanced, improving the imaging quality of the optical lens. More specifically: 0.79 < R5 / R6 < 0.96.

[0071] In some embodiments, the radius of curvature R8 of the image side surface of the fourth lens and the radius of curvature R9 of the object side surface of the fifth lens satisfy: 0.7 < R8 / R9 < 1.2. Meeting the above ranges is beneficial to balancing the axial aberration of the optical lens, correcting the off-axis aberration of the optical lens, reducing the optical sensitivity of the optical lens, and improving the imaging quality of the optical lens. More specifically: 0.77 < R8 / R9 < 1.12.

[0072] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis respectively and the optical total length TTL of the optical lens satisfy: 0.45 < ∑CT / TTL < 0.6. Meeting the above ranges, controlling the optical total length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range can facilitate the structural design and processing, and further improve the imaging quality. More specifically: 0.51 < ∑CT / TTL < 0.56.

[0073] In some embodiments, the focal length f5 of the fifth lens and the distance CT45 between the fourth lens and the fifth lens on the optical axis satisfy: 35 < f5 / CT45 < 45. Meeting the above range is beneficial to balancing the performance and physical size of the optical system, ensuring that the entire optical system can be more compact on the premise of meeting a certain imaging quality. More specifically: 37.1 < f5 / CT45 < 43.1.

[0074] In some embodiments, the optical lens satisfies the following conditional expressions: 2 mm < f < 2.5 mm; 90° < FOV < 100°; 1 mm < EPD < 1.3 mm; 2.4 mm < TTL < 2.8 mm; 1.8 < Fno < 2.2; 4.8 mm < IH < 5.6 mm; 40° < CRA < 50°; 0.55 mm < BFL < 0.75 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, IH represents the true image height corresponding to the maximum field of view angle of the optical lens, CRA represents the principal ray incident angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as miniaturization, large image plane, and high imaging quality. More specifically: 2.27 mm < f < 2.3 mm; 94.98° < FOV < 95.02°; 1.13 mm < EPD < 1.16 mm; 2.59 mm < TTL < 2.61 mm; 1.99 < Fno < 2.01; 5.18 mm < IH < 5.24 mm; 44.81° < CRA < 45.39°; 0.63 mm < BFL < 0.67 mm.

[0075] 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. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-plastic lens structure, which can make the structure of the lens relatively compact, and can better achieve the balance of miniaturization and high image quality of the lens, and reduce the cost.

[0076] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth 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, and the sixth lens of the present invention all adopt aspherical lenses.

[0077] In various embodiments of the present invention, when the lens is an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0078] ;

[0079] Among them, z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, B, C, D, E, F, G, H, I, and J are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order, eighteenth-order, and twentieth-order surface coefficients respectively.

[0080] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate 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.

[0081] Example 1

[0082] See also Figure 1 , shown is a schematic diagram of the structure of the optical lens 100 provided in Example 1 of the present invention, and the optical lens 100 includes, along the optical axis from the object side to the imaging surface, an aperture ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter G1.

[0083] The first lens L1 has positive refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0084] The second lens L2 has positive refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0085] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave;

[0086] The fourth lens L4 has negative refractive power, its object-side surface S7 is convex, and its image-side surface S8 is concave;

[0087] The fifth lens L5 has positive refractive power, its object-side surface S9 is convex, and its image-side surface S10 is convex;

[0088] The sixth lens L6 has negative refractive power, its object-side surface S11 is convex, and its image-side surface S12 is concave;

[0089] The object side surface S13 and the image side surface S14 of the filter G1 are both planes;

[0090] The imaging surface S15 is a plane.

[0091] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all plastic aspherical lenses.

[0092] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0093] Table 1-1

[0094]

[0095] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0096] Table 1-2

[0097]

[0098] In this embodiment, the F-Tan (Theta) distortion curve, the vertical axis chromatic aberration curve, and the axial aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 shown.

[0099] Figure 2 The F-Tan (Theta) distortion curve of Example 1 is shown, which represents the F-Tan (Theta) distortion at different image heights on the imaging plane, the horizontal axis represents the F-Tan (Theta) distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the F-Tan (Theta) distortion of the optical lens 100 is controlled within -3% to 4%, indicating that the distortion of the optical lens 100 is well corrected.

[0100] Figure 3 The vertical chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging surface, the horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±4 μm, indicating that the optical lens 100 can perfectly correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image surface.

[0101] Figure 4The 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. It can be seen from the figure that the offset of the axial aberration is controlled within -0.04mm~0.09mm, indicating that the optical lens 100 can better correct the axial aberration.

[0102] Example 2

[0103] See also Figure 5 , shown is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0104] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0105] Table 2-1

[0106]

[0107] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0108] Table 2-2

[0109]

[0110] In this embodiment, the F-Tan (Theta) distortion curve, the vertical axis chromatic aberration curve, and the axial aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 shown.

[0111] from Figure 6 It can be seen that the F-Tan (Theta) distortion of the optical lens is controlled within -3%~4%, indicating that the distortion of the optical lens 200 is well corrected.

[0112] from Figure 7 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±3μm, indicating that the optical lens 200 can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0113] from Figure 8 It can be seen that the offset of the axial aberration is controlled within -0.04mm~0.10mm, which means that the optical lens 200 can correct the axial aberration well.

[0114] Example 3

[0115] See also Fig. 9 , shown is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0116] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0117] Table 3-1

[0118]

[0119] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0120] Table 3-2

[0121]

[0122] In this embodiment, the F-Tan (Theta) distortion curve, the vertical axis chromatic aberration curve, and the axial aberration curve of the optical lens 300 are respectively as follows: Fig.10 , Fig.11 , Fig.12 shown.

[0123] from Fig.10 It can be seen that the F-Tan (Theta) distortion of the optical lens is controlled within -2%~4%, indicating that the distortion of the optical lens 300 is well corrected.

[0124] from Fig.11 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±3μm, indicating that the optical lens 300 can extremely well correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0125] from Fig.12 It can be seen that the offset of the axial aberration is controlled within -0.04mm~0.09mm, which means that the optical lens 300 can correct the axial aberration well.

[0126] Example 4

[0127] See also Fig.13 , shown is a schematic diagram of the structure of the optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, the main differences of this embodiment are: the image side surface of the fifth lens is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0128] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0129] Table 4-1

[0130]

[0131] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0132] Table 4-2

[0133]

[0134] In this embodiment, the F-Tan (Theta) distortion curve, the vertical axis chromatic aberration curve, and the axial aberration curve of the optical lens 400 are respectively as follows: Fig.14 , Fig.15 , Fig.16 shown.

[0135] from Fig.14 It can be seen that the F-Tan (Theta) distortion of the optical lens is controlled within -3%~4%, indicating that the distortion of the optical lens 400 is well corrected.

[0136] from Fig.15 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -4μm~5μm, which means that the optical lens 400 can perfectly correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0137] from Fig.16 It can be seen that the offset of the axial aberration is controlled within -0.04mm~0.10mm, which means that the optical lens 400 can correct the axial aberration well.

[0138] Please refer to Table 5-1 and Table 5-2, which are the optical characteristics corresponding to the above-mentioned embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the main ray incidence angle CRA at the maximum image height, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, the entrance pupil diameter EPD, the back focal length BFL and the numerical value corresponding to each conditional expression in each embodiment.

[0139] Table 5-1

[0140]

[0141] Table 5-2

[0142]

[0143] In summary of the above embodiments, the optical lens provided by the present invention adopts six lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as miniaturization, large image surface, and high imaging quality.

[0144] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", 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 invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0145] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, comprising six lenses, characterized in that: It successively includes from the object side to the imaging surface along the optical axis: A first lens with positive optical power, whose object side is convex and whose image side is concave; A second lens with positive optical power, whose object side is convex and whose image side is concave; A third lens with positive optical power, whose object side is convex and whose image side is concave; A fourth lens with negative optical power, whose object side is convex and whose image side is concave; A fifth lens with positive optical power, whose object side is convex; A sixth lens with negative optical power, whose object side is convex and whose image side is concave; Wherein, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.4; the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 12 < f2 / f < 24; the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1 < TTL / f < 1.

2.

2. The optical lens according to claim 1, characterized in that: The focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: f3 / f > 55; the curvature radius R5 of the object side of the third lens and the curvature radius R6 of the image side of the third lens satisfy: -42 < (R5 + R6) / (R5 - R6) < -8.

3. The optical lens according to claim 1, characterized in that: The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.8 < f5 / f < 1.2; the curvature radius R9 of the object side of the fifth lens and the effective focal length f of the optical lens satisfy: 0.4 < R9 / f < 0.

75.

4. The optical lens according to claim 1, characterized in that: The combined focal length f34 of the third lens and the fourth lens and the combined focal length f56 of the fifth lens and the sixth lens satisfy: -1 < f34 / f56 < -0.

6.

5. The optical lens according to claim 1, characterized in that: The curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 2.2 < R5 / f < 7.8; the curvature radius R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R6 / f < 9.

5.

6. The optical lens according to claim 1, characterized in that: The curvature radius R7 of the object side of the fourth lens and the effective focal length f of the optical lens satisfy: 2.3 < R7 / f < 3.6; the curvature radius R8 of the image side of the fourth lens and the effective focal length f of the optical lens satisfy: 0.5 < R8 / f < 0.

6.

7. The optical lens according to claim 1, characterized in that: The curvature radius R11 of the object side of the sixth lens and the effective focal length f of the optical lens satisfy: 1.4 < R11 / f < 2.9; the curvature radius R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: 0.6 < R12 / f < 0.

9.

8. The optical lens according to claim 1, characterized in that: The curvature radius R3 of the object side of the second lens and the focal length f2 of the second lens satisfy: 0.05 < R3 / f2 < 0.25; the curvature radius R4 of the image side of the second lens and the focal length f2 of the second lens satisfy: 0.1 < R4 / f2 < 0.

35.

9. The optical lens according to claim 1, characterized in that: The curvature radius R7 of the object side of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: 1.2 < (R7 + R8) / (R7 - R8) < 1.

7.

10. The optical lens according to claim 1, characterized in that: The sagittal height Sag5 of the clear aperture on the object side of the third lens and the clear aperture diameter d5 of the object side of the third lens satisfy: -0.05 < Sag5 / d5 < -0; the sagittal height Sag6 of the clear aperture on the image side of the third lens and the clear aperture diameter d6 of the image side of the third lens satisfy: -0.1 < Sag6 / d6 < -0.01.

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