Optical lens

Abstract

The invention provides an optical lens, which comprises six lenses which sequentially comprise a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with negative focal power from an object side to an imaging surface along an optical axis, the image side surface of the second lens is a convex surface; the object side surface of the third lens is a concave surface; the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a concave surface, and the image side surface of the fifth lens is a convex surface; and the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a concave surface near the optical axis. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal 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.

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, with the continuous improvement of consumers' requirements for the photography quality of smart phones. The 6P optical lens is more and more widely used, not only in high-end models, but also in many mid-range and low-end mobile phones, in order to enhance their competitiveness in the mobile phone market. The 6P optical lens still occupies the mainstream position in the market due to its cost-effectiveness and good performance. At the same time, consumers' demand for the performance of mobile phone cameras is constantly increasing. A large aperture and a large image plane can bring a larger light input and better image quality. At the same time, for the portability and beauty of mobile phones, it is also required that the optical lens has a thin, light, short and small shape, which makes the lens design difficulty increase exponentially. How to meet the requirements of large aperture and high pixel while maintaining the miniaturization of the lens is also a difficult point in lens design at the present stage. Summary of the Invention

[0003] Aiming at the above problems, the purpose of the present invention is to provide an optical lens with excellent imaging quality.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An optical lens, comprising a total of six lenses, which are sequentially arranged from the object side to the imaging surface along the optical axis:

[0006] A first lens with positive optical power, the object side surface thereof is convex, and the image side surface thereof is concave;

[0007] A second lens with positive optical power, the image side surface thereof is convex;

[0008] A third lens with negative optical power, the object side surface thereof is concave;

[0009] A fourth lens with positive optical power, the image side surface thereof is convex;

[0010] A fifth lens with positive optical power, the object side surface thereof is concave, and the image side surface thereof is convex;

[0011] A sixth lens with negative optical power, the object side surface thereof is concave, and the image side surface thereof is concave near the optical axis;

[0012] Wherein, the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: 1.1 < f123 / f < 1.3; the radius of curvature R6 of the image side surface of the third lens, the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 37 < (R6 + R7) / f < 68.

[0013] More preferably, the effective focal length f, the maximum field of view FOV, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1 < (IH / 2) / (f×tan(FOV / 2)) < 1.03; the half-aperture d1 of the object side of the first lens, the true 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: 0.3 < d1 / (IH / 2) / tan(FOV / 2) < 0.4.

[0014] More preferably, the maximum field of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 53° < FOV / Fno < 57°; the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3 < IH / EPD < 3.3.

[0015] More preferably, the true 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: 1.8 < IH / f < 2.1; the true image height IH corresponding to the maximum field of view of the optical lens and the back focal length BFL of the optical lens satisfy: 7 < IH / BFL < 8.

[0016] More preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.4 < f5 / f < 0.6; the radius of curvature R9 of the object side of the fifth lens and the effective focal length f of the optical lens satisfy: -12.2 < R9 / f < -3.7; the radius of curvature R10 of the image side of the fifth lens and the effective focal length f of the optical lens satisfy: -0.4 < R10 / f < -0.2.

[0017] More preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -0.4 < f6 / f < -0.3; the radius of curvature R11 of the object side of the sixth lens and the effective focal length f of the optical lens satisfy: -0.7 < R11 / f < -0.4; the radius of curvature R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: 0.35 < R12 / f < 0.5.

[0018] More preferably, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.5 < f3 / f4 < -0.2; the radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the object side of the fourth lens satisfy: -25 < R6 / R7 < 0.

[0019] More preferably, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.2 < f2 / f3 < -1; the radius of curvature R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: -1.1 < R4 / f < -0.7; the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -1.3 < R5 / f < -0.6.

[0020] More preferably, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -1.5 < f5 / f6 < -1.3; the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side satisfy: 13.1 < R9 / R10 < 36.5; the radius of curvature R10 of the image side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 0.5 < R10 / R11 < 0.7.

[0021] More preferably, the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side satisfy: 0.8 < (R9 - R10) / (R9 + R10) < 1; the radius of curvature R11 of the object side of the sixth lens and the radius of curvature R12 of the image side satisfy: 0 < (R11 - R12) / (R11 + R12) < 0.2;

[0022] The image side of the third lens is convex, and the object side of the fourth lens is convex near the optical axis; or the image side of the third lens is concave near the optical axis, and the object side of the fourth lens is concave.

[0023] Compared with the prior art, the optical lens provided by the present invention uses six lenses with specific optical powers. Through specific surface shape settings and reasonable optical power distribution, the lens can simultaneously have the characteristics of a large image plane and a large aperture. The large image plane helps to improve the resolution of the lens, and the large aperture enables the lens to have excellent imaging quality even in dark environments at night. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, where:

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

[0026] Figure 2 is the field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 Graph showing the vertical axis chromatic aberration of the optical lens in Example 1 of the present invention.

[0029] Figure 5 Graph showing the axial aberration of the optical lens in Example 1 of the present invention.

[0030] Figure 6 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0031] Figure 7 Graph showing the field curvature of the optical lens in Embodiment 2 of the present invention.

[0032] Figure 8 : is the F-Tan (Theta) distortion curve of the optical lens in Example 2 of the present invention.

[0033] Fig. 9 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0034] Fig.10 Graph showing the axial aberration of the optical lens in Embodiment 2 of the present invention.

[0035] Fig.11 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0036] Fig.12 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0037] Fig.13 : is the F-Tan (Theta) distortion curve of the optical lens in Example 3 of the present invention.

[0038] Fig.14 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0039] Fig.15 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0040] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] The optical lens provided by the embodiment of the present invention comprises six lenses in total, which include, in sequence from the object side to the imaging surface along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens.

[0049] In some embodiments, the first lens may have a positive focal power, with its object side being convex and its image side being concave. The second lens may have a positive focal power, with its object side being concave or convex near the optical axis, and its image side being concave. The third lens may have a negative focal power, with its object side being concave and its image side being convex or concave near the optical axis. The fourth lens may have a positive focal power, with its object side being concave or convex near the optical axis, and its image side being convex. The fifth lens may have a positive focal power, with its object side being concave and its image side being convex. The sixth lens may have a negative focal power, with its object side being concave and its image side being concave near the optical axis.

[0050] In some embodiments, the image side of the third lens is convex, and the object side of the fourth lens is convex near the optical axis; or the image side of the third lens is concave near the optical axis, and the object side of the fourth lens is concave near the optical axis.

[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 can be used to limit the amount of incident light to change the brightness of the imaging.

[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 combined focal length f123 of the first lens, the second lens, and the third lens and the effective focal length f of the optical lens satisfy: 1.1 < f123 / f < 1.3; the radius of curvature R6 of the image side of the third lens, the radius of curvature R7 of the object side of the fourth lens, and the effective focal length f of the optical lens satisfy: 37 < (R6 + R7) / f < 68. By satisfying the above ranges, through reasonable distribution of the focal power of the front lens group of the optical lens and the surface type limitation of the image side of the third lens and the object side of the fourth lens, the optical total length of the optical lens can be effectively shortened, which is beneficial to the miniaturization and light weight of the optical lens, and can reasonably control the degree of light deflection, which is beneficial to improving the imaging effect of the optical lens. More specifically, 1.15 < f123 / f < 1.26, 37.76 < (R6 + R7) / f < 67.98.

[0054] In some embodiments, the effective focal length f, the maximum field of view FOV, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 1 < (IH / 2) / (f×tan(FOV / 2)) < 1.03; the half clear aperture d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.3 < d1 / (IH / 2) / tan(FOV / 2) < 0.4. Meeting the above ranges indicates that the optical distortion of the optical lens is well controlled, making the imaging of each field of view clearer and improving the resolution of the optical lens; and by reasonably controlling the relationship between the front aperture of the optical lens, the true image height corresponding to the maximum field of view, and the maximum field of view, it helps to meet the small head requirement of the optical lens and improve the structural rationality of the optical lens. More specifically, 0.3 < d1 / (IH / 2) / tan(FOV / 2) < 0.36.

[0055] In some embodiments, the maximum field of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 53° < FOV / Fno < 57°; the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3 < IH / EPD < 3.3. Meeting the above ranges makes the aperture match the field of view angle, which is beneficial to expanding the field of view angle of the optical lens and increasing the aperture of the optical lens, facilitating the acquisition of more picture information and meeting the requirements of large-range detection. The characteristic of a large aperture enables the optical lens to be able to take pictures in a darker environment, and at the same time helps with background blurring, making the main body more prominent; and it can make the width of the light beam incident on the optical lens at different field of view angles reasonable, improve the brightness of the optical lens at the image plane, avoid vignetting, and at the same time increase the image height of the optical lens, facilitating the backend chip to obtain more picture information and reducing the information processing pressure of the backend chip. More specifically, 53.74° < FOV / Fno < 56.97°, 3.02 < IH / EPD < 3.23.

[0056] In some embodiments, the true 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: 1.8 < IH / f < 2.1; the true image height IH corresponding to the maximum field of view of the optical lens and the back focal length BFL of the optical lens satisfy: 7 < IH / BFL < 8. Meeting the above ranges can achieve the large image plane characteristic, match a large-size chip, and improve the imaging quality of the optical lens. More specifically, 1.88 < IH / f < 2.05, 7.17 < IH / BFL < 7.43.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.4 < f5 / f < 0.6; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -12.2 < R9 / f < -3.7; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -0.4 < R10 / f < -0.2. Satisfying the above ranges, by reasonably defining the proportion of the focal length of the fifth lens and the shapes of the object side surface and the image side surface of the fifth lens, it helps to control the degree of light deflection and improve the imaging quality of the optical lens. More specifically, 0.45 < f5 / f < 0.54, -12.12 < R9 / f < -3.76, -0.34 < R10 / f < -0.28.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -0.4 < f6 / f < -0.3; the radius of curvature R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -0.7 < R11 / f < -0.4; the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.35 < R12 / f < 0.5. Satisfying the above ranges, by reasonably defining the proportion of the focal length of the sixth lens and the shapes of the object side surface and the image side surface of the sixth lens, it helps to reasonably adjust the light path and the incident angle of the light relative to the image plane, reduce the sensitivity of the optical lens, improve the imaging quality of the optical lens, and at the same time helps to achieve the large image plane feature. More specifically, -0.4 < f6 / f < -0.32, -0.63 < R11 / f < -0.48, 0.39 < R12 / f < 0.48.

[0059] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.5 < f3 / f4 < -0.2; the radius of curvature R6 of the image side surface of the third lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: -25 < R6 / R7 < 0. Satisfying the above ranges, by reasonably defining the proportion of the focal lengths of the third lens and the fourth lens, and the shapes of the image side surface of the third lens and the object side surface of the fourth lens, it helps to correct various aberrations of the optical lens, improve the imaging quality of the optical lens, and improve the picture clarity. More specifically, -0.5 < f3 / f4 < -0.24, -24.83 < R6 / R7 < -0.04.

[0060] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.2 < f2 / f3 < -1; the radius of curvature R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: -1.1 < R4 / f < -0.7; the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -1.3 < R5 / f < -0.6. Meeting the above ranges, by reasonably defining the ratio of the focal lengths of the second lens and the third lens, as well as the shapes of the image side of the second lens and the object side of the third lens, it helps to reduce field curvature and at the same time reduce the difficulty of aberration correction for the rear lenses. More specifically, -1.16 < f2 / f3 < -1.03, -1.05 < R4 / f < -0.72, -1.26 < R5 / f < -0.66.

[0061] In some embodiments, the focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -1.5 < f5 / f6 < -1.3; the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side satisfy: 13.1 < R9 / R10 < 36.5; the radius of curvature R10 of the image side of the fifth lens and the radius of curvature R11 of the object side of the sixth lens satisfy: 0.5 < R10 / R11 < 0.7. Meeting the above ranges, by reasonably defining the ratio of the focal lengths of the fifth lens and the sixth lens, as well as the shapes of the object side of the fifth lens, the image side of the fifth lens, and the object side of the sixth lens, it helps to correct the aberration of the peripheral field of view and improve the imaging quality of the peripheral field of view. More specifically, -1.46 < f5 / f6 < -1.33, 13.16 < R9 / R10 < 36.47, 0.5 < R10 / R11 < 0.64.

[0062] In some embodiments, the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side satisfy: 0.8 < (R9 - R10) / (R9 + R10) < 1; the radius of curvature R11 of the object side of the sixth lens and the radius of curvature R12 of the image side satisfy: 0 < (R11 - R12) / (R11 + R12) < 0.2. Meeting the above ranges, by reasonably defining the shapes of the object side and the image side of the fifth lens, as well as the object side and the image side of the sixth lens, it can reasonably control the degree of light deflection, reduce aberration, and improve imaging quality. More specifically, 0.85 < (R9 - R10) / (R9 + R10) < 0.96, 0.01 < (R11 - R12) / (R11 + R12) < 0.17.

[0063] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.2 < TTL / f < 1.4; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.6 < TTL / IH < 0.7. Meeting the above ranges is beneficial to shortening the total length of the optical lens while taking into account good imaging quality, realizing miniaturization of the optical lens, and meeting the requirements of miniaturization and large image plane in mobile phone application scenarios. More specifically, 1.27 < TTL / f < 1.33, 0.64 < TTL / IH < 0.69.

[0064] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.6 < ∑CT / TTL < 0.7, and the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis and the effective focal length f of the optical lens satisfy: 0.8 < ∑CT / f < 0.9. Meeting the above ranges can achieve high pixel characteristics, improve the imaging quality of the optical lens, and is beneficial to meeting the processability of each lens and reducing production costs. More specifically, 0.62 < ∑CT / TTL < 0.66, 0.81 < ∑CT / f < 0.84.

[0065] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1.1 < f1 / f < 1.3. Meeting the above range can endow the first lens with an appropriate positive optical power, which is beneficial to the convergence of light rays, optimize aberrations, and improve resolution. More specifically, 1.1 < f1 / f < 1.24.

[0066] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.3 < f2 / f < 1.9. Meeting the above range can endow the second lens with an appropriate positive optical power, and can reduce the influence of spherical aberration and astigmatism on the optical lens, and improve the imaging quality of the optical lens. More specifically, 1.36 < f2 / f < 1.9.

[0067] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1.9 < f3 / f < -1.2. Meeting the above range can endow the third lens with an appropriate negative optical power, which is beneficial to balancing various aberrations generated by the optical lens and improving the imaging quality of the optical lens. More specifically, -1.82 < f3 / f < -1.26.

[0068] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 3.3 < f4 / f < 5.1, and the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -3.6 < R8 / f < -1.2. Meeting the above ranges can endow the fourth lens with an appropriate positive optical power, reasonably control the shape of the image side surface of the fourth lens, reduce the spherical aberration and coma generated by itself, and improve the imaging quality of the optical lens. More specifically, 3.33 < f4 / f < 5.02, -3.51 < R8 / f < -1.2.

[0069] In some embodiments, the edge spacing ET12 between the first lens and the second lens, the edge spacing ET23 between the second lens and the third lens, the edge spacing ET34 between the third lens and the fourth lens, the edge spacing ET45 between the fourth lens and the fifth lens, the edge spacing ET56 between the fifth lens and the sixth lens, and the overall optical length TTL of the optical lens satisfy: 0 < (ET12 + ET23 + ET34 + ET45 + ET56) / TTL < 0.1. Meeting the above range can reduce the edge spacing between adjacent lenses, make the optical lens structure compact, and can reduce the number of assembly spacers, thereby reducing the production cost of the optical lens. More specifically, 0.05 < (ET12 + ET23 + ET34 + ET45 + ET56) / TTL < 0.1.

[0070] In some embodiments, the sagittal height Sag6 of the clear aperture and the clear aperture diameter d6 of the image side surface of the third lens satisfy: -0.2 < Sag6 / d6 < -0.1, and the sagittal height Sag7 / d7 of the clear aperture of the object side surface of the fourth lens satisfies: -0.2 < Sag7 / d7 < -0.1. Meeting the above ranges can effectively improve the imaging quality of the marginal field of view and the imaging quality of the optical lens by reasonably controlling the clear aperture of the image side surface of the third lens and the corresponding sagittal height, as well as the clear aperture of the object side surface of the fourth lens and the corresponding sagittal height. More specifically, -0.16 < Sag6 / d6 < -0.1, -0.2 < Sag7 / d7 < -0.18.

[0071] In some embodiments, the optical lens satisfies the conditional formula: 4.2 mm < f < 4.6 mm, 85° < FOV < 91°, 2.6 mm < EPD < 2.9 mm, 5.5 mm < TTL < 5.9 mm, 1.5 < Fno < 1.7, 8.5 mm < IH < 8.7 mm, 37° < CRA < 39°, 1.1 mm < BFL < 1.3 mm; where 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 f-number of the optical lens, IH represents the image height corresponding to the maximum field of view angle of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least the characteristics of small volume, large image plane, large aperture, etc. More specifically, 4.22 mm < f < 4.55 mm, 85.9° < FOV < 90.1°, 2.66 mm < EPD < 2.85 mm, 5.56 mm < TTL < 5.83 mm, 1.57 < Fno < 1.61, 8.56 mm < IH < 8.63 mm, 37.65° < CRA < 38.52°, 1.14 mm < BFL < 1.21 mm.

[0072] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. Additionally, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low-dispersion characteristic of the glass itself. The first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens in the optical lens provided by the present invention all adopt plastic lenses.

[0073] In some embodiments, the first lens, second lens, third lens, fourth lens, fifth lens, and 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, second lens, third lens, fourth lens, fifth lens, and sixth lens of the present invention can all adopt aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens.

[0074] In various embodiments of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0075]

[0076] Among them, z is the distance vector height from the vertex of the aspherical surface when the aspherical surface is at a height of h along the optical axis, c is the curvature of the vertex of the surface, K is the quadratic surface coefficient, B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0077] 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.

[0078] Example 1

[0079] 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.

[0080] The first lens L1 has positive refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0081] The second lens L2 has positive refractive power, its object-side surface S3 is concave, and its image-side surface S4 is convex;

[0082] The third lens L3 has negative refractive power, its object-side surface S5 is concave, and its image-side surface S6 is convex;

[0083] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex at the near optical axis, and its image-side surface S8 is convex;

[0084] The fifth lens L5 has positive refractive power, its object-side surface S9 is concave, and its image-side surface S10 is convex;

[0085] The sixth lens L6 has negative refractive power, its object-side surface S11 is concave, and its image-side surface S12 is concave at the near optical axis;

[0086] The object side surface S13 and the image side surface S14 of the filter G1 are both planes;

[0087] The imaging surface S15 is a plane.

[0088] 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.

[0089] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0090] Table 1-1

[0091]

[0092] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0093] Table 1-2

[0094]

[0095]

[0096] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, vertical axis chromatic aberration curve, and axial aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 shown.

[0097] Figure 2 The field curvature curve of Example 1 is shown, which indicates the degree of curvature of light of different wavelengths on the meridional image plane and the sagittal image plane, with the horizontal axis indicating the offset (unit: mm) and the vertical axis indicating the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within -0.1mm to 0.2mm, indicating that the optical lens can correct the field curvature well.

[0098] Figure 3 The F-Tan (Theta) distortion curve of Example 1 is shown, which represents the distortion of light of different wavelengths at different image heights on the imaging surface, with the horizontal axis representing the distortion value (unit: %) and the vertical axis representing the half field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within ±1%, indicating that the optical lens can correct the distortion well.

[0099] Figure 4 The vertical axis chromatic aberration curve of the optical lens 100 in this embodiment 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 axis 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 axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1.5 μm to 1 μm, indicating that the optical lens can correct chromatic aberration well.

[0100] Figure 5 The axial aberration curve of the optical lens 100 in this embodiment 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 ±0.05mm, indicating that the optical lens can better correct the axial aberration.

[0101] Example 2

[0102] See also Figure 6 , 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 differences of this embodiment are: the image side surface S6 of the third lens L3 is a concave surface at the near optical axis, the object side surface S7 of the fourth lens L4 is a concave surface, and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0103] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0104] Table 2-1

[0105]

[0106] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0107] Table 2-2

[0108]

[0109]

[0110] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, vertical axis chromatic aberration curve, and axial aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Fig. 9 , Fig.10 shown.

[0111] from Figure 7 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.2mm, indicating that the optical lens can correct the field curvature well.

[0112] from Figure 8 It can be seen that the distortion of the optical lens is controlled within ±1%, indicating that the optical lens can correct the distortion well.

[0113] from Fig. 9It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm to 1.5μm, indicating that the optical lens can correct chromatic aberration well.

[0114] from Fig.10 It can be seen that the offset of axial aberration is controlled within ±0.05mm, which means that the optical lens can correct axial aberration well.

[0115] Example 3

[0116] See also Fig.11 , 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 differences of this embodiment are: the object side surface S3 of the second lens L2 is convex at the near optical axis, the image side surface S6 of the third lens L3 is concave at the near optical axis, the object side surface S7 of the fourth lens L4 is concave, and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0117] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0118] Table 3-1

[0119]

[0120]

[0121] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0122] Table 3-2

[0123]

[0124]

[0125] In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, vertical axis chromatic aberration curve, and axial aberration curve of the optical lens 300 are respectively as follows: Fig.12 , Fig.13 , Fig.14 , Fig.15 shown.

[0126] from Fig.12 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.2mm, indicating that the optical lens can correct the field curvature well.

[0127] from Fig.13 It can be seen that the distortion of the optical lens is controlled within -0.5% to 1.5%, indicating that the optical lens can correct the distortion well.

[0128] from Fig.14 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±2μm, indicating that the optical lens can correct chromatic aberration well.

[0129] from Fig.15 It can be seen that the offset of axial aberration is controlled within -0.08mm~0.05mm, which means that the optical lens can correct axial aberration well.

[0130] Please refer to Table 4, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0131] Table 4

[0132]

[0133]

[0134] In summary of the above embodiments, the optical lens provided by the present invention can improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens through a specific surface shape setting and a reasonable distribution of optical focal length, so that the optical lens has the advantages of miniaturization, high pixels, and low distortion, which is in line with the development of increasingly miniaturized and high-performance mobile devices. The small total optical length is conducive to better miniaturization and portability; the large aperture means that it can be used for shooting in darker environments, and it is also conducive to blurring the background, making the subject more prominent; the small edge distance between any two lenses can reduce the assembly of the spacer and reduce the cost of the overall lens; low distortion can provide more accurate and clear imaging effects.

[0135] 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.

[0136] 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 sequentially 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 image side is convex; A third lens with negative optical power, whose object side is concave; A fourth lens with positive optical power, whose image side is convex; A fifth lens with positive optical power, whose object side is concave and whose image side is convex; A sixth lens with negative optical power, whose object side is concave and whose image side is concave near the optical axis; Wherein, the combined focal length f123 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: 1.1 < f123 / f < 1.3; the radius of curvature R6 of the image side of the third lens, the radius of curvature R7 of the object side of the fourth lens and the effective focal length f of the optical lens satisfy: 37 < (R6 + R7) / f < 68.

2. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens, the maximum field of view angle FOV and the true image height IH corresponding to the maximum field of view angle satisfy: 1 < (IH / 2) / (f×tan(FOV / 2)) < 1.03; the clear aperture radius d1 of the object side of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens and the maximum field of view angle FOV of the optical lens satisfy: 0.3 < d1 / (IH / 2) / tan(FOV / 2) < 0.

4.

3. The optical lens according to claim 1, characterized in that: The maximum field of view angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 53° < FOV / Fno < 57°; the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3 < IH / EPD < 3.

3.

4. The optical lens according to claim 1, characterized in that: 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: 1.8 < IH / f < 2.1; the true image height IH corresponding to the maximum field of view angle of the optical lens and the back focal length BFL of the optical lens satisfy: 7 < IH / BFL < 8.

5. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.4 < f5 / f < 0.6; the radius of curvature R9 of the object side of the fifth lens and the effective focal length f of the optical lens satisfy: -12.2 < R9 / f < -3.7; the radius of curvature R10 of the image side of the fifth lens and the effective focal length f of the optical lens satisfy: -0.4 < R10 / f < -0.

2.

6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -0.4 < f6 / f < -0.3; the radius of curvature R11 of the object side of the sixth lens and the effective focal length f of the optical lens satisfy: -0.7 < R11 / f < -0.4; the radius of curvature R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: 0.35 < R12 / f < 0.

5.

7. The optical lens according to claim 1, characterized in that: The focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.5 < f3 / f4 < -0.2; the curvature radius R6 of the image side of the third lens and the curvature radius R7 of the object side of the fourth lens satisfy: -25 < R6 / R7 < 0.

8. The optical lens according to claim 1, characterized in that: The focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.2 < f2 / f3 < -1; the curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: -1.1 < R4 / f < -0.7; the curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: -1.3 < R5 / f < -0.

6.

9. The optical lens according to claim 1, characterized in that: The focal length f5 of the fifth lens and the focal length f6 of the sixth lens satisfy: -1.5 < f5 / f6 < -1.3; the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side satisfy: 13.1 < R9 / R10 < 36.5; the curvature radius R10 of the image side of the fifth lens and the curvature radius R11 of the object side of the sixth lens satisfy: 0.5 < R10 / R11 < 0.

7.

10. The optical lens according to claim 1, characterized in that: The curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side satisfy: 0.8 < (R9 - R10) / (R9 + R10) < 1; the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side satisfy: 0 < (R11 - R12) / (R11 + R12) < 0.2; The image side of the third lens is convex, and the object side of the fourth lens is convex near the optical axis; or the image side of the third lens is concave near the optical axis, and the object side of the fourth lens is concave.

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