Optical lens

Abstract

The invention provides an optical lens which sequentially comprises a first lens with positive focal power from an object side to an imaging surface along an optical axis, a second lens with negative focal power, a third lens with positive focal power and a fourth lens with negative focal power from the object side to the imaging surface, the object side surface of the second lens is a concave 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 near the optical axis, and the image side surface of the third lens is a concave surface near the optical axis; 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 concave surface; wherein the optical total length TTL of the optical lens, the real image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens meet the following conditions: 46lt; 180 degrees * TTL / IH / FOVlt; 51. According to the optical lens provided by the invention, through specific surface shape setting 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 in particular to an optical lens. Background Art

[0002] Currently, with the popularization of portable electronic devices and the popularity of social, video, and live streaming software, people's love for photography is increasing. Camera lenses have become a standard configuration for electronic devices, and even the primary consideration for consumers when purchasing electronic devices. To improve the imaging quality of distant objects, most flagship mobile phones are equipped with a telephoto optical lens, which can clearly magnify the scene when shooting a distant view and effectively blur the background to highlight the subject, thereby improving the quality of mobile phone photography. However, although the common five-element optical lens already has good optical performance, it cannot simultaneously meet the design requirements of ultra-long focal length and high imaging quality, affecting the user's shooting experience. Summary of the Invention

[0003] In view of the above problems, the object of the present invention is to provide an optical lens with excellent imaging quality and other advantages.

[0004] The technical solution adopted by the present invention is as follows: An optical lens, comprising a total of five lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface: A first lens with positive optical power, the object side surface of which is convex, and the image side surface of which is concave near the optical axis; A second lens with negative optical power, the object side surface of which is concave, and the image side surface of which is concave; A third lens with optical power, the object side surface of which is convex near the optical axis, and the image side surface of which is concave near the optical axis; A fourth lens with positive optical power, the image side surface of which is convex; A fifth lens with negative optical power, the object side surface of which is concave, and the image side surface of which is concave; Wherein, the total optical length TTL of the optical 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: 46 < 180°×TTL / IH / FOV < 51.

[0005] Further preferably, the effective focal length f of the optical lens and the total optical length TTL of the optical lens satisfy: 0.75 < TTL / f < 0.85; 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: 3.3 < TTL / IH < 3.7.

[0006] More preferably, the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the FOV of the maximum field of view angle of the optical lens satisfy: 1 < (IH / 2) / (f×Tan(FOV / 2)) < 1.02; the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 2.8° < FOV / Fno < 2.9°.

[0007] More preferably, 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: 1 < IH / EPD < 1.05; 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: 0.8 < IH / BFL < 1.

[0008] More preferably, the half clear aperture 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 FOV of the maximum field of view angle of the optical lens satisfy: 8.5 < d1 / (IH / 2) / tan(FOV / 2) < 8.8; the half clear aperture d1 of the object side of the first lens and the half clear aperture d10 of the image side of the fifth lens satisfy: 1.3 < d1 / d10 < 1.4; the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 4.35 < f / IH < 4.45.

[0009] More preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 0.35 < f1 / f < 0.5; the effective focal length f of the optical lens and the object side curvature radius R1 of the first lens satisfy: 0.15 < R1 / f < 0.25; the effective focal length f of the optical lens and the image side curvature radius R2 of the first lens satisfy: 1.8 < R2 / f < 2.2.

[0010] More preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -0.55 < f2 / f < -0.25; the object side curvature radius R3 and the image side curvature radius R4 of the second lens satisfy: 0.3 < (R3 + R4) / (R3 - R4) < 0.7.

[0011] More preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.35 < f4 / f < 0.45; the focal length f4 of the fourth lens and the image side curvature radius R8 of the fourth lens satisfy: -13.5 < R8 / f4 < -0.5.

[0012] More preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -0.5 < f5 / f < -0.25; the effective focal length f of the optical lens and the object-side curvature radius R9 of the fifth lens satisfy: -0.35 < R9 / f < -0.2; the effective focal length f of the optical lens and the image-side curvature radius R10 of the fifth lens satisfy: 0.45 < R10 / f < 5.

[0013] More preferably, the focal length f3 of the third lens and the object-side curvature radius R7 of the fourth lens satisfy: 6.6 < f3 / R7 < 52.8; the object-side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: 0.15 < R5 / f < 8.5; the image-side curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 0.15 < R6 / f < 3.3.

[0014] More preferably, the object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: -0.5 < R9 / R10 < 0; the object-side curvature radius R9 of the fifth lens and the image-side curvature radius R10 of the fifth lens satisfy: -1 < (R9 + R10) / (R9 - R10) < -0.3.

[0015] Compared with the prior art, the optical lens provided by the present invention can improve the imaging quality of the optical lens, reduce aberration, and improve the imaging quality of the optical lens through specific surface shape settings and reasonable optical power distribution, enabling the lens to have one or more advantages such as ultra-long focal length, large target surface, small distortion, and high pixel. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, wherein: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 is an F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 is an axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 is a lateral chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0022] Figure 7 It is a field curvature curve diagram of the optical lens in Example 2 of the present invention.

[0023] Figure 8 Graph showing the F-Theta distortion of the optical lens in Embodiment 2 of the present invention.

[0024] Fig. 9 Graph showing the axial aberration of the optical lens in Embodiment 2 of the present invention.

[0025] Fig.10 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0026] Fig.11 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0027] Fig.12 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0028] Fig.13 Graph showing the F-Theta distortion of the optical lens in Embodiment 3 of the present invention.

[0029] Fig.14 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0030] Fig.15 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0031] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] The optical lens provided by the embodiment of the present invention comprises five lenses in total, which are a first lens, a second lens, a third lens, a fourth lens and a fifth lens in order from the object side to the imaging surface along the optical axis.

[0040] In some embodiments, the first lens may have a positive optical power, with its object side being convex and its image side being concave near the optical axis. The second lens may have a negative optical power, with its object side being concave and its image side being concave. The third lens may have a positive or negative optical power, with its object side being convex near the optical axis and its image side being concave near the optical axis. The fourth lens may have a positive optical power, with its object side being either concave or convex and its image side being convex. The fifth lens may have a negative optical power, with its object side being concave and its image side being concave.

[0041] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the object side and the first lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging.

[0042] In some embodiments, the optical lens may further include a filter, and the filter is disposed between the fifth 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.

[0043] In some embodiments, the total optical length TTL of the optical 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: 46 < 180°×TTL / IH / FOV < 51. Meeting the above range is beneficial to balancing the relationship among the total length, image height, and field of view angle of the optical lens. More specifically, 46.77 < 180°×TTL / IH / FOV < 50.33.

[0044] In some embodiments, the effective focal length f of the optical lens and the total optical length TTL of the optical lens satisfy: 0.75 < TTL / f < 0.85. Meeting the above range can effectively limit the length of the lens, which is beneficial to realizing the miniaturization of the optical lens and also has an ultra-long focal length. More specifically, 0.75 < TTL / f < 0.84.

[0045] In some embodiments, 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: 3.3 < TTL / IH < 3.7. Meeting the above range is beneficial to realizing large image plane imaging while shortening the total optical length, achieving the balance between the miniaturization of the optical lens and large image plane imaging. More specifically, 3.32 < TTL / IH < 3.64.

[0046] In some embodiments, the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the FOV of the maximum field of view angle of the optical lens satisfy: 1 < (IH / 2) / (f×Tan(FOV / 2)) < 1.02. Meeting the above range, the optical distortion of the optical lens is better controlled, the resolution of the optical lens is improved, and better imaging effects can be obtained.

[0047] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 2.8° < FOV / Fno < 2.9°. Meeting the above range limits the optical lens to have an appropriate field of view angle and aperture value, and good imaging quality can be obtained. More specifically, 2.83° < FOV / Fno < 2.9°.

[0048] In some embodiments, 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: 1 < IH / EPD < 1.05. Meeting the above range can increase the width of the light beam entering the optical lens, improve the relative illumination, and avoid vignetting. More specifically, 1.01 < IH / EPD < 1.04.

[0049] In some embodiments, 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: 0.8 < IH / BFL < 1. Meeting the above range is beneficial to ensuring that the optical system has a long back focus, and the distribution of the lenses in the optical lens in space can be reasonably allocated to achieve high pixels. More specifically, 0.83 < IH / BFL < 0.96.

[0050] In some embodiments, the clear aperture radius d1 of the object side of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 8.5 < d1 / (IH / 2) / tan(FOV / 2) < 8.8. Meeting the above range can have a small front aperture while meeting the requirements of a large field of view angle and a large image plane for the optical lens, which is beneficial to the miniaturization of the optical lens. More specifically, 8.52 < d1 / (IH / 2) / tan(FOV / 2) < 8.73.

[0051] In some embodiments, the clear aperture radius d1 of the object side of the first lens and the clear aperture radius d10 of the image side of the fifth lens satisfy: 1.3 < d1 / d10 < 1.4. Meeting the above range reasonably matches the aperture ratio of the first lens and the fifth lens, facilitating the structural design and at the same time helping to improve the imaging quality of the optical lens. More specifically, 1.31 < d1 / d10 < 1.36.

[0052] In some embodiments, the effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 4.35 < f / IH < 4.45. Meeting the above range helps to achieve a long focal length and a large image plane, and improve the imaging quality of the optical lens. More specifically, 4.36 < f / IH < 4.41.

[0053] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 0.35 < f1 / f < 0.5; the effective focal length f of the optical lens and the curvature radius R1 of the object side surface of the first lens satisfy: 0.15 < R1 / f < 0.25; the effective focal length f of the optical lens and the curvature radius R2 of the image side surface of the first lens satisfy: 1.8 < R2 / f < 2.2. Meeting the above ranges, by reasonably setting the focal length and surface shape of the first lens, the light entering the first lens can be well converged into the optical system, increasing the light flux, which is beneficial to reducing the difficulty of aberration correction and ensuring the imaging quality of the optical lens. More specifically, 0.36 < f1 / f < 0.46; 0.18 < R1 / f < 0.24; 1.82 < R2 / f < 2.14.

[0054] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -0.55 < f2 / f < -0.25; the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: 0.3 < (R3 + R4) / (R3 - R4) < 0.7. Meeting the above ranges, by reasonably setting the focal length and surface shape of the second lens, it is beneficial to avoid excessive light deflection caused by overly concentrated optical power of the first lens, reducing the difficulty of aberration correction, and at the same time facilitating large image plane imaging of the lens. More specifically, -0.52 < f2 / f < -0.29; 0.31 < (R3 + R4) / (R3 - R4) < 0.7.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.35 < f4 / f < 0.45; the focal length f4 of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -13.5 < R8 / f4 < -0.5. Meeting the above ranges, by reasonably setting the focal length of the fourth lens and the surface shape of the image side surface, the light can be effectively converged, the light path direction can be controlled, and the difficulty of aberration correction can be reduced. More specifically, 0.36 < f4 / f < 0.44; -13.45 < R8 / f4 < -0.53.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -0.5 < f5 / f < -0.25; the effective focal length f of the optical lens and the curvature radius R9 of the object side surface of the fifth lens satisfy: -0.35 < R9 / f < -0.2; the effective focal length f of the optical lens and the curvature radius R10 of the image side surface of the fifth lens satisfy: 0.45 < R10 / f < 5. Meeting the above ranges and reasonably setting the focal length and surface shape of the fifth lens are beneficial to achieving a large image surface and are conducive to balancing various aberrations of the optical lens, thereby improving the overall imaging quality. More specifically, -0.49 < f5 / f < -0.26; -0.32 < R9 / f < -0.21; 0.46 < R10 / f < 4.97.

[0057] In some embodiments, the focal length f3 of the third lens and the curvature radius R7 of the object side surface of the fourth lens satisfy: 6.6 < f3 / R7 < 52.8; the curvature radius R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 0.15 < R5 / f < 8.5; the curvature radius R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: 0.15 < R6 / f < 3.3. Meeting the above ranges and reasonably matching the positive and negative optical powers of the third lens and the surface shape of the object side surface of the fourth lens can control the combination of the third lens with negative optical power and the concave surface of the object side surface of the fourth lens, and the combination of the third lens with positive optical power and the convex surface of the object side surface of the fourth lens, which helps the fourth lens receive more light from the front-end lens, can improve the ability to converge the marginal field light, and improve the imaging quality of the marginal field. More specifically, 6.64 < f3 / R7 < 52.73; 0.19 < R5 / f < 8.47; 0.17 < R6 / f < 3.26.

[0058] In some embodiments, 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: -0.5 < R9 / R10 < 0; 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: -1 < (R9 + R10) / (R9 - R10) < -0.3. Meeting the above ranges and controlling the surface shape of the fifth lens are beneficial to increasing the imaging area and field angle of the optical lens, are conducive to balancing the aberrations of the optical lens, and improving the imaging quality of the optical lens. More specifically, -0.48 < R9 / R10 < -0.04; -0.91 < (R9 + R10) / (R9 - R10) < -0.35.

[0059] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis satisfy: 0.25 < ∑CT / TTL < 0.5. Satisfying the above range can effectively compress the total length of the optical lens, and is beneficial to the structural design and production process of the optical lens. More specifically, 0.28 < ∑CT / TTL < 0.5.

[0060] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis and the effective focal length f of the optical lens satisfy: 0.2 < ∑CT / f < 0.45. Satisfying the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens. More specifically, 0.21 < ∑CT / f < 0.42.

[0061] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 2.7 < |f3 / f| < 13.6. Satisfying the above range, the third lens can be a positive or negative optical power, so that the positive and negative of the optical power of the third lens are reasonably matched with the surface shape of the object side of the fourth lens. More specifically, 2.71 < |f3 / f| < 13.52.

[0062] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f34 of the third lens and the fourth lens satisfy: 1.6 < f12 / f34 < 16.4. Satisfying the above range, by reasonably setting the relationship between the optical powers of the combined focal lengths of the first lens and the second lens and the combined focal lengths of the third lens and the fourth lens in the lens, the incident light can be converged to a certain extent, which is beneficial to realizing the long focal length performance of the lens. More specifically, 1.62 < f12 / f34 < 16.34.

[0063] In some embodiments, the sagittal height Sag1 of the object side clear aperture semi-diameter of the first lens and the object side clear aperture semi-diameter d1 of the first lens satisfy: 0.25 < Sag1 / d1 < 0.31; the sagittal height Sag10 of the image side clear aperture semi-diameter of the fifth lens and the image side clear aperture semi-diameter d10 of the second lens satisfy: 0.02 < |Sag10 / d10| < 0.09. Satisfying the above range helps to control the trend of the marginal field light and highlight the detailed information of the central field of the optical lens.

[0064] In some embodiments, the optical lens satisfies the conditional formula: 37 mm < f < 38 mm, 8.4 mm < EPD < 8.5 mm, 28 mm < TTL < 32 mm, 4.4 < Fno < 4.6, 12.5° < CRA < 13°, 9 mm < BFL < 11 mm, 12.5° < FOV < 13.5°, 8.5 mm < IH < 8.8 mm; where f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the overall optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the principal ray angle of incidence at the maximum image height of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least characteristics such as long focal length and large target surface. More specifically, 37.88 mm < f < 37.91 mm, 8.41 mm < EPD < 8.43 mm, 28.63 mm < TTL < 31.51 mm, 4.49 < Fno < 4.51, 12.77° < CRA < 12.99°, 9.02 mm < BFL < 10.32 mm, 12.79° < FOV < 13.01°, 8.6 mm < IH < 8.68 mm.

[0065] In some embodiments, the lens material of 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 characteristics 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 not only enables the lens to have excellent imaging performance, but also makes the structure of the lens relatively compact, and can better achieve the balance between lens miniaturization and high image quality.

[0066] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth 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 lens miniaturization. More specifically, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens of the present invention can all adopt aspherical lenses.

[0067] 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 equations: ; 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.

[0068] 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.

[0069] 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 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 and a filter G1.

[0070] The first lens L1 has positive refractive power, its object side surface S1 is convex, and its image side surface S2 is concave at the near optical axis; The second lens L2 has negative refractive power, its object-side surface S3 is concave, and its image-side surface S4 is concave; The third lens L3 has negative refractive power, an object-side surface S5 thereof is convex at the near optical axis, and an image-side surface S6 thereof is concave at the near optical axis; The fourth lens L4 has positive refractive power, its object-side surface S7 is concave, and its image-side surface S8 is convex; The fifth lens L5 has negative refractive power, its object-side surface S9 is concave, and its image-side surface S10 is concave; The object side surface S11 and the image side surface S12 of the filter G1 are both planes; The imaging surface S13 is a plane.

[0071] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all plastic aspherical lenses.

[0072] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0073] Table 1-1 The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0074] Table 1-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and vertical axis chromatic aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 shown.

[0075] Figure 2 The field curvature curve of Example 1 is shown, which represents the field curvature of light on the meridional image plane and the sagittal image plane, the horizontal axis represents the offset (unit: mm), and the vertical axis represents 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 -0.3mm~0.1mm, indicating that the optical lens 100 can well correct the field curvature.

[0076] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion at different image heights on the imaging surface, the horizontal axis represents the F-Theta distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the F-Theta distortion of the optical lens 100 is controlled within 0~1.5%, indicating that the distortion of the optical lens 100 is well corrected.

[0077] Figure 4 The axial aberration curve of the present embodiment 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. As can be seen from the figure, the offset of the axial aberration is controlled within -0.05mm~0.15mm, indicating that the optical lens 100 can better correct the axial aberration.

[0078] Figure 5 The vertical chromatic aberration curve of Example 1 is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging surface, the horizontal axis represents the vertical chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the 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, indicating that the optical lens 100 can extremely well correct the chromatic aberration of each field of view.

[0079] 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 differences of this embodiment are: the third lens L3 has positive focal power; the object side surface S7 of the fourth lens L4 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0080] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0081] Table 2-1 The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0082] Table 2-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, and vertical chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Fig. 9 , Fig.10 shown.

[0083] 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~0.1mm, which means that the optical lens 200 can correct the field curvature well.

[0084] from Figure 8 It can be seen that the F-Theta distortion of the optical lens 200 is controlled within 0~0.6%, indicating that the distortion of the optical lens 200 is well corrected.

[0085] from Fig. 9 It can be seen that the offset of the axial aberration is controlled within -0.05mm~0.15mm, which means that the optical lens 200 can correct the axial aberration well.

[0086] from Fig.10 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 200 can extremely well correct the chromatic aberration of each field of view.

[0087] 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 third lens L3 has positive focal length; the object side surface S7 of the fourth lens L4 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0088] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0089] Table 3-1 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0090] Table 3-2 In this embodiment, the field curvature curve, F-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.

[0091] 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~0.1mm, which means that the optical lens 300 can correct the field curvature well.

[0092] from Fig.13 It can be seen that the F-Theta distortion of the optical lens 300 is controlled within 0~0.4%, indicating that the distortion of the optical lens 300 is well corrected.

[0093] from Fig.14 It can be seen that the offset of the axial aberration is controlled within -0.05mm~0.1mm, which means that the optical lens 300 can correct the axial aberration well.

[0094] from Fig.15 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 300 can extremely well correct the chromatic aberration of each field of view.

[0095] 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 chief ray incident angle CRA at the maximum image height, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0096] Table 4 In summary, the optical lens provided by the present invention has at least the following advantages: (1) Through specific surface shape settings and reasonable optical focal length distribution, the lens has an ultra-long focal length, which can better present larger local details, making the picture more focused and compact, thereby meeting local shooting needs; ensuring large target surface imaging, and being able to match imaging chips with larger target surfaces to achieve high-definition imaging.

[0097] (2) The optical lens of the present invention can reasonably correct the overall aberration of the optical lens. The overall lens aberration is small and has the characteristics of small distortion and small chromatic aberration, thereby improving the imaging quality of the optical lens.

[0098] 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.

[0099] 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 five 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 near the optical axis; A second lens with negative optical power, whose object side is concave and whose image side is concave; A third lens with optical power, whose object side is convex near the optical axis and whose image side is concave near the optical axis; A fourth lens with positive optical power, whose image side is convex; A fifth lens with negative optical power, whose object side is concave and whose image side is concave; Wherein, the total optical length TTL of the optical 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: 46 < 180°×TTL / IH / FOV < 51.

2. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the total optical length TTL of the optical lens satisfy: 0.75 < TTL / f < 0.85; 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: 3.3 < TTL / IH < 3.

7.

3. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the FOV of the maximum field of view angle of the optical lens satisfy: 1 < (IH / 2) / (f×Tan(FOV / 2)) < 1.02; The maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 2.8° < FOV / Fno < 2.9°.

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 entrance pupil diameter EPD of the optical lens satisfy: 1 < IH / EPD < 1.05; 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: 0.8 < IH / BFL < 1.

5. The optical lens according to claim 1, characterized in that: The clear aperture semi-diameter 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: 8.5 < d1 / (IH / 2) / tan(FOV / 2) < 8.8; The clear aperture semi-diameter d1 of the object side of the first lens and the clear aperture semi-diameter d10 of the image side of the fifth lens satisfy: 1.3 < d1 / d10 < 1.4; The effective focal length f of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 4.35 < f / IH < 4.

45.

6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 0.35 < f1 / f < 0.5; The effective focal length f of the optical lens and the curvature radius R1 of the object side of the first lens satisfy: 0.15 < R1 / f < 0.25; The effective focal length f of the optical lens and the curvature radius R2 of the image side of the first lens satisfy: 1.8 < R2 / f < 2.

2.

7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -0.55 < f2 / f < -0.25; the curvature radius R3 of the object side of the second lens and the curvature radius R4 of the image side of the second lens satisfy: 0.3 < (R3 + R4) / (R3 - R4) < 0.

7.

8. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.35 < f4 / f < 0.45; the focal length f4 of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: -13.5 < R8 / f4 < -0.

5.

9. 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: -0.5 < f5 / f < -0.25; the effective focal length f of the optical lens and the curvature radius R9 of the object side of the fifth lens satisfy: -0.35 < R9 / f < -0.2; the effective focal length f of the optical lens and the curvature radius R10 of the image side of the fifth lens satisfy: 0.45 < R10 / f < 5.

10. The optical lens according to claim 1, characterized in that: The focal length f3 of the third lens and the curvature radius R7 of the object side of the fourth lens satisfy: 6.6 < f3 / R7 < 52.8; the curvature radius R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 0.15 < R5 / f < 8.5; the curvature radius R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: 0.15 < R6 / f < 3.

3.

11. 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 of the fifth lens satisfy: -0.5 < R9 / R10 < 0; 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) < -0.3.

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