Optical lens

Abstract

The invention provides an optical lens, which comprises seven lenses from an object side to an imaging surface along an optical axis: 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, the object side surface of the second lens near the optical axis is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface near the optical axis; the object side surface of the fourth lens is a convex surface near the optical axis, and the image side surface of the fourth lens is a concave surface near the optical axis; the object side surface of the fifth lens is a concave surface near the optical axis, and the image side surface of the fifth lens is a concave surface near the optical axis; the sixth lens has positive focal power, the object side surface of the sixth lens is a convex surface near the optical axis, and the image side surface of the sixth lens is a concave surface near the optical axis; and the object side surface of the seventh lens is a convex surface near the optical axis, and the image side surface of the seventh lens is a concave surface near the optical axis. The optical lens provided by the invention has one or more advantages of short total length, large aperture, small distortion and the like.

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, consumers' requirements for the photography quality of smart phones have been continuously increasing. They not only require the phone lenses to be thin and light, but also require the captured image quality to be clear and bright in various environments. However, among the existing phone lenses on the market, some have a relatively long overall length, which is not conducive to the thin and light design of the phone; while others have a relatively small aperture, resulting in insufficient brightness when shooting in a relatively dim surrounding environment, making the image quality blurred. Therefore, the mainstream trend in the development of consumer electronics products is towards ultra-thinness and high-definition imaging in complex environments, which poses higher requirements for the optical lenses mounted on electronic products. 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: An optical lens, comprising a total of seven lenses, which in sequence from the object side to the imaging surface along the optical axis include: A first lens with positive optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is convex near the optical axis and whose image side is concave; A third lens with positive optical power, whose object side is convex and whose image side is concave near the optical axis; A fourth lens with positive optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A fifth lens with negative optical power, whose object side is concave near the optical axis and whose image side is concave near the optical axis; A sixth lens with positive optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A seventh lens with negative optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; Wherein, the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side of the fifth lens satisfy: -1 < (R9 + R10) / (R9 - R10) < 0.

[0005] Further preferably, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.25 < TTL / f < 1.35; the overall 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: 0.65 < TTL / IH < 0.69.

[0006] More preferably, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 57° < FOV / Fno < 60°; 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: 2.8 < IH / EPD < 3.1.

[0007] 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: 1.85 < IH / f < 2.05; 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: 7.7 < IH / BFL < 8.8.

[0008] More preferably, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis and the overall optical length TTL of the optical lens satisfy: 0.55 < ΣCT / TTL < 0.59; the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 0.71 < ΣCT / f < 0.78; the curvature radius R9 of the object side surface of the fifth lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: -0.92 < (R9 + R10) / (R9 - R10) < -0.13.

[0009] More preferably, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1.9 < f1 / f < 2.7; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.49 < R1 / f < 0.56; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.74 < R2 / f < 1.04.

[0010] More preferably, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.8 < f2 / f < -2.1; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < R3 / f < 0.96; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.43 < R4 / f < 0.57.

[0011] More preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.3 < f5 / f < -1; 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: -2.68 < R9 / f < -0.74; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 3.51 < R10 / f < 16.09.

[0012] More preferably, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -2.6 < f7 / f < -1.1; the radius of curvature R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.49 < R13 / f < 0.92; the radius of curvature R14 of the image side surface of the seventh lens and the effective focal length f of the optical lens satisfy: 0.32 < R14 / f < 0.41.

[0013] More preferably, the sagittal height Sag9 of the object side clear aperture of the fifth lens and the object side clear aperture diameter d9 of the fifth lens satisfy: -0.25 < Sag9 / d9 < -0.19; the sagittal height Sag10 of the image side clear aperture of the fifth lens and the image side clear aperture diameter d10 of the fifth lens satisfy: -0.21 < Sag10 / d10 < -0.11.

[0014] The optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as short overall length, large aperture, and small distortion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0016] Figure 2 is a field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 3 is an F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 4 is an axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 5 is a lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 6 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0021] Figure 7 4 is a field curvature curve diagram of the optical lens in Example 2 of the present invention.

[0022] Figure 8 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 2 of the present invention.

[0023] Fig. 9 Graph showing the axial aberration of the optical lens in Embodiment 2 of the present invention.

[0024] Fig.10 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0025] Fig.11 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0026] Fig.12 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0027] Fig.13 Graph showing the F-Tan (Theta) distortion of the optical lens in Example 3 of the present invention.

[0028] Fig.14 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0029] Fig.15 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0030] Fig.16 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0031] Fig.17 It is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0032] Fig.18 4 is a F-Tan (Theta) distortion curve of the optical lens in Example 4 of the present invention.

[0033] Fig.19 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0034] Fig. 20 Graph showing the vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0035] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] The optical lens provided by the embodiment of the present invention comprises seven lenses, which are a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in order from the object side to the imaging surface along the optical axis.

[0044] In some embodiments, the first lens may have positive optical power, the object side surface thereof may be convex, and the image side surface thereof may be concave. The second lens may have negative optical power, the object side surface thereof may be convex at the near optical axis, and the image side surface thereof may be concave. The third lens may have positive optical power, the object side surface thereof may be convex, and the image side surface thereof may be concave at the near optical axis. The fourth lens may have positive optical power, the object side surface thereof may be convex at the near optical axis, and the image side surface thereof may be concave at the near optical axis. The fifth lens may have negative optical power, the object side surface thereof may be concave at the near optical axis, and the image side surface thereof may be concave at the near optical axis. The sixth lens may have positive optical power, the object side surface thereof may be convex at the near optical axis, and the image side surface thereof may be concave at the near optical axis. The seventh lens may have negative optical power, the object side surface thereof may be convex at the near optical axis, and the image side surface thereof may be concave at the near optical axis.

[0045] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the object side and the first lens. It is understood that the aperture is used to limit the amount of incoming light to change the brightness of the image.

[0046] In some embodiments, the optical lens may further include a filter, which may be disposed between the seventh lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0047] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface of the fifth lens satisfy: -1<(R9+R10) / (R9-R10)<0. By satisfying the above range, by reasonably limiting the shapes of the object side surface and the image side surface of the fifth lens, the fifth lens can be controlled to have an appropriate surface shape, and the aberration of the optical lens can be effectively corrected. More specifically: -0.92<(R9+R10) / (R9-R10)<-0.13.

[0048] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.25 < TTL / f < 1.35; 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: 0.65 < TTL / IH < 0.69. Satisfying the above ranges can effectively limit the length of the lens, which is beneficial to reducing the volume of the optical lens. At the same time, it ensures that when the lens is used for wide-angle shooting, it still maintains a compact structure and has the characteristic of a short total length. More specifically: 1.28 < TTL / f < 1.34.

[0049] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 57° < FOV / Fno < 60°; 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: 2.8 < IH / EPD < 3.1. Satisfying the above ranges, reasonably limiting the ratio of the maximum field of view angle to the aperture, is beneficial to ensuring a large field of view while increasing the light input, and thus achieving high-pixel imaging. At the same time, reasonably limiting the ratio of the image height to the entrance pupil diameter is beneficial to balancing the imaging quality and the volume of the lens. More specifically: 57.32° < FOV / Fno < 59.34°; 2.84 < IH / EPD < 3.03.

[0050] 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: 1.85 < IH / f < 2.05; 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: 7.7 < IH / BFL < 8.8. Satisfying the above ranges is beneficial to controlling the field of view angle within a suitable range. At the same time, the lens has the characteristic of miniaturization. More specifically: 1.89 < IH / f < 2.02; 7.77 < IH / BFL < 8.77.

[0051] In some embodiments, the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis and the total optical length TTL of the optical lens satisfy: 0.55 < ΣCT / TTL < 0.59; the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 0.71 < ΣCT / f < 0.78. Satisfying the above ranges, controlling the total optical 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. At the same time, controlling the effective focal length of the optical lens and the sum of the central thicknesses of each lens within a reasonable range makes the lens more compact, which is beneficial to realizing the miniaturization of the lens.

[0052] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1.9 < f1 / f < 2.7; the object-side curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: 0.49 < R1 / f < 0.56; the image-side curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: 0.74 < R2 / f < 1.04. Satisfying the above ranges, by reasonably defining the proportion of the optical power of the first lens and its surface shape, it is beneficial to diverge light and improve the brightness of the peripheral field of view. More specifically: 1.94 < f1 / f < 2.7.

[0053] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.8 < f2 / f < -2.1; the object-side curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < R3 / f < 0.96; the image-side curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 0.43 < R4 / f < 0.57. Satisfying the above ranges, by reasonably defining the proportion of the optical power of the second lens and its surface shape, it is beneficial to obtain a wider field of view without changing the physical size of the lens. More specifically: -3.74 < f2 / f < -2.13.

[0054] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.3 < f5 / f < -1; the object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.68 < R9 / f < -0.74; the image-side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 3.51 < R10 / f < 16.09. Satisfying the above ranges, by reasonably defining the proportion of the optical power of the fifth lens and its surface shape, it can effectively balance the lens aberration and improve the imaging quality. More specifically: -2.25 < f5 / f < -1.03.

[0055] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -2.6 < f7 / f < -1.1; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.49 < R13 / f < 0.92; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.32 < R14 / f < 0.41. Satisfying the above ranges, by reasonably defining the proportion of the optical power of the seventh lens and its surface shape, it is beneficial to reduce the aberration and distortion. More specifically: -2.53 < f7 / f < -1.11.

[0056] In some embodiments, the sagittal height Sag9 of the clear aperture on the object side of the fifth lens and the clear aperture d9 of the object side of the fifth lens satisfy: -0.25 < Sag9 / d9 < -0.19; the sagittal height Sag10 of the clear aperture on the image side of the fifth lens and the clear aperture d10 of the image side of the fifth lens satisfy: -0.21 < Sag10 / d10 < -0.11. Meeting the above ranges helps to control the light path and highlight the detailed information of the central field of view of the optical lens.

[0057] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1.1 < f3 / f < 1.7. Meeting the above range reasonably limits the proportion of the optical power of the third lens, which is beneficial to balancing spherical aberration, resulting in smaller axial aberration and good imaging quality. More specifically: 1.12 < f3 / f < 1.7.

[0058] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 3.1 < f4 / f < 6.6. Meeting the above range reasonably limits the proportion of the optical power of the fourth lens, which is beneficial to balancing lens aberration and improving imaging quality. More specifically: 3.15 < f4 / f < 6.52.

[0059] In some embodiments, the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 1 < f6 / f < 1.7; the radius of curvature R11 of the object side of the sixth lens and the effective focal length f of the optical lens satisfy: 0.39 < R11 / f < 0.48; the radius of curvature R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: 0.75 < R12 / f < 0.91. Meeting the above ranges can improve the imaging quality of the optical system and make the image more real and natural by reasonably limiting the proportion of the optical power of the sixth lens and its surface shape. More specifically: 1.02 < f6 / f < 1.63.

[0060] In some embodiments, the radius of curvature R7 of the object side of the fourth lens and the radius of curvature R8 of the image side of the fourth lens satisfy: -1.39 < (R7 + R8) / (R7 - R8) < -1.13. Meeting the above range can control the fourth lens to have an appropriate surface shape by reasonably limiting the shapes of the object side and the image side of the fourth lens, effectively improving field curvature and aberration and enhancing imaging quality.

[0061] In some embodiments, the optical lens satisfies the following conditional expressions: 4 mm < f < 5 mm; 85° < FOV < 90°; 2.8 mm < EPD < 3.1 mm; 5.5 mm < TTL < 6 mm; 1.4 < Fno < 1.6; 8.5 mm < IH < 8.7 mm; 38° < CRA < 40°; 0.95 mm < BFL < 1.15 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 ranges, the optical lens has at least one or more advantages such as a short total length, a large aperture, and small distortion. More specifically: 4.27 mm < f < 4.54 mm; 85.9° < FOV < 89.1°; 2.84 mm < EPD < 3.03 mm; 5.66 mm < TTL < 5.88 mm; 1.49 < Fno < 1.51; 8.58 mm < IH < 8.64 mm; 38.13° < CRA < 39.64°; 0.97 mm < BFL < 1.11 mm.

[0062] 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, due to the low dispersion characteristic of the glass itself, the geometric chromatic aberration of the optical system can be effectively corrected. The optical lens provided by the present invention can adopt an all-plastic lens structure, which can make the structure of the lens relatively compact, and can better achieve the balance between the miniaturization of the lens and high image quality, and reduce costs.

[0063] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens of the present invention all adopt aspherical lenses.

[0064] In each embodiment of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equation: ; 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.

[0065] 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.

[0066] Example 1 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, a seventh lens L7 and a filter G1.

[0067] The first lens L1 has positive refractive power, its object side surface S1 is convex, and its image side surface S2 is concave; The second lens L2 has negative refractive power, its object side surface S3 is convex at the near optical axis, and its image side surface S4 is concave; The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is concave; The fourth lens L4 has positive refractive power, an object-side surface S7 thereof is convex at the near optical axis, and an image-side surface S8 thereof is concave at the near optical axis; The fifth lens L5 has negative refractive power, its object side surface S9 is concave, and its image side surface S10 is concave at the near optical axis; The sixth lens L6 has positive refractive power, an object-side surface S11 thereof is convex at the near optical axis, and an image-side surface S12 thereof is concave at the near optical axis; The seventh lens L7 has negative refractive power, an object-side surface S13 thereof is convex at the near optical axis, and an image-side surface S14 thereof is concave at the near optical axis; The object side surface S15 and the image side surface S16 of the filter G1 are both planes; The imaging surface S17 is a plane.

[0068] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are all plastic aspherical lenses.

[0069] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0070] Table 1-1 The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0071] Table 1-2 In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 shown.

[0072] 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 ±0.08 mm, indicating that the optical lens 100 can well correct the field curvature.

[0073] Figure 3 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 0%~2%, indicating that the distortion of the optical lens 100 is well corrected.

[0074] Figure 4 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane, 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~0.03mm, indicating that the optical lens 100 can correct the axial aberration well.

[0075] Figure 5The 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 -1.5 μm~1 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.

[0076] Example 2 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 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.

[0077] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0078] Table 2-1 The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0079] Table 2-2 In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 200 are shown as follows: Figure 7 , Figure 8 , Fig. 9 , Fig.10 shown.

[0080] from Figure 7 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within -0.08mm~0.06mm, indicating that the optical lens 200 can correct the field curvature well.

[0081] from Figure 8 It can be seen that the F-Tan (Theta) distortion of the optical lens is controlled within -0.5%~1.8%, indicating that the distortion of the optical lens 200 is well corrected.

[0082] from Fig. 9 It can be seen that the offset of the axial aberration is controlled within ±0.03 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0083] from Fig.10It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~1.5μm, which means that the optical lens 200 can perfectly correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0084] Example 3 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 image side surface S6 of the third lens L3 is a concave surface at the near optical axis; the object side surface S9 of the fifth lens L5 is a concave surface at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0085] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0086] Table 3-1 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0087] Table 3-2 In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 300 are respectively as follows: Fig.12 , Fig.13 , Fig.14 , Fig.15 shown.

[0088] from Fig.12 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within -0.12mm~0.04mm, indicating that the optical lens 300 can correct the field curvature well.

[0089] from Fig.13 It can be seen that the F-Tan (Theta) distortion of the optical lens is controlled within 0%~1.8%, indicating that the distortion of the optical lens 300 is well corrected.

[0090] from Fig.14 It can be seen that the offset of the axial aberration is controlled within ±0.02 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0091] from Fig.15 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1μm~1.5μm, which means that the optical lens 300 can perfectly correct the chromatic aberration of the edge field of view and the secondary spectrum of the entire image plane.

[0092] Example 4 See also Fig.16 , 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 S6 of the third lens L3 is concave at the near optical axis; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0093] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0094] Table 4-1 The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0095] Table 4-2 In this embodiment, the field curvature curve, F-Tan (Theta) distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 400 are respectively as follows: Fig.17 , Fig.18 , Fig.19 , Fig. 20 shown.

[0096] from Fig.17 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within -0.08mm~0.07mm, indicating that the optical lens 400 can correct the field curvature well.

[0097] from Fig.18 It can be seen that the F-Tan (Theta) distortion of the optical lens is controlled within -0.5%~2%, indicating that the distortion of the optical lens 400 is well corrected.

[0098] from Fig.19 It can be seen that the offset of the axial aberration is controlled within ±0.03 mm, indicating that the optical lens 400 can correct the axial aberration well.

[0099] from Fig. 20 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within -1.5μm~1μm, 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.

[0100] 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.

[0101] Table 5-1 Table 5-2 In summary of the above embodiments, the optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it 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 short total length, large aperture, and small distortion.

[0102] 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.

[0103] 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 seven lenses, characterized in that: From the object side to the imaging plane along the optical axis, it sequentially includes: A first lens with positive optical power, whose object side is convex and whose image side is concave; A second lens with negative optical power, whose object side is convex near the optical axis and whose image side is concave; A third lens with positive optical power, whose object side is convex and whose image side is concave near the optical axis; A fourth lens with positive optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A fifth lens with negative optical power, whose object side is concave near the optical axis and whose image side is concave near the optical axis; A sixth lens with positive optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A seventh lens with negative optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; Wherein, the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: -1 < (R9 + R10) / (R9 - R10) < 0.

2. The optical lens according to claim 1, characterized in that: The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.25 < TTL / f < 1.35; 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: 0.65 < TTL / IH < 0.

69.

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: 57° < FOV / Fno < 60°; 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: 2.8 < IH / EPD < 3.

1.

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: 1.85 < IH / f < 2.05; 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: 7.7 < IH / BFL < 8.

8.

5. The optical lens according to claim 1, characterized in that: The sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the total optical length TTL of the optical lens satisfy: 0.55 < ΣCT / TTL < 0.59; the sum ΣCT of the central thicknesses of the first lens to the seventh lens along the optical axis respectively and the effective focal length f of the optical lens satisfy: 0.71 < ΣCT / f < 0.78; the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: -0.92 < (R9 + R10) / (R9 - R10) < -0.

13.

6. The optical lens according to claim 1, characterized in that: The focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: 1.9 < f1 / f < 2.7; the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: 0.49 < R1 / f < 0.56; the curvature radius R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: 0.74 < R2 / f < 1.

04.

7. The optical lens according to claim 1, characterized in that: The focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -3.8 < f2 / f < -2.1; the object-side curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < R3 / f < 0.96; the image-side curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 0.43 < R4 / f < 0.

57.

8. 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: -2.3 < f5 / f < -1; the object-side curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -2.68 < R9 / f < -0.74; the image-side curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: 3.51 < R10 / f < 16.

09.

9. The optical lens according to claim 1, characterized in that: The focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: -2.6 < f7 / f < -1.1; the object-side curvature radius R13 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.49 < R13 / f < 0.92; the image-side curvature radius R14 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.32 < R14 / f < 0.

41.

10. The optical lens according to claim 1, characterized in that: The object-side clear aperture sagittal height Sag9 of the fifth lens and the object-side clear aperture d9 of the fifth lens satisfy: -0.25 < Sag9 / d9 < -0.19; the image-side clear aperture sagittal height Sag10 of the fifth lens and the image-side clear aperture d10 of the fifth lens satisfy: -0.21 < Sag10 / d10 < -0.11.

Images