Optical lens

Abstract

The invention provides an optical lens, which sequentially comprises a first lens with negative 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 near the optical axis is a convex 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; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has focal power, and the object side surface of the fifth lens is a concave surface; the sixth lens has positive focal power, and the image side surface of the sixth lens is a convex surface; the object side surface of the seventh lens is a concave surface, and the image side surface of the seventh lens is a convex surface; the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens near the optical axis is a convex surface; and the image side surface of the ninth lens is a concave surface near the optical axis. The imaging quality of the optical lens can be improved, and the optical lens has the advantage of being excellent in imaging quality.

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] With the rapid development of drones, security, automobiles and other fields, the pursuit of imaging effects of the lenses they carry has become more diversified. At present, drones are developing rapidly and have won the favor of consumers with their unique high-altitude perspective and wide-angle shooting images. Correspondingly, the demand for optical lenses that match them is also increasing. The optical lenses they carry require not only high-definition image quality, but also the ability to present larger local details, so as to achieve high-altitude vision and fully express local details, and shoot local close-up images.

[0003] However, the field of view of drone lenses on the market is too small to fully detect changes in the surrounding environment. How to better achieve a large field of view and high imaging quality is still an urgent problem to be solved. Summary of the invention

[0004] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0005] The present invention provides an optical lens, comprising nine lenses in total, which include the following lenses in order from the object side to the imaging surface along the optical axis: The first lens has a negative optical power, the object side surface of which is convex, and the image side surface of which is concave; The second lens has a negative optical power, the object side surface of which is concave, and the image side surface of which is convex near the optical axis; The third lens has positive power, its object side surface is convex, and its image side surface is concave; a fourth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is convex; a fifth lens having optical power and having a concave object side surface; a sixth lens element having positive refractive power and having a convex image-side surface; The seventh lens has positive refractive power, its object side surface is concave, and its image side surface is convex; The eighth lens with negative optical power has a concave object side surface and a convex image side surface near the optical axis; The ninth lens element has a negative optical power and its image side surface is concave at the near optical axis; The combined focal length fa of the first lens, the second lens and the third lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens satisfy the following conditions: -1.5 <fa / fb<-0.8。

[0006] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5 < TTL / f < 7; 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: 1.5 < TTL / IH < 2.3.

[0007] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -1.8; the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.8 < f1 / f2 < 1.

[0008] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3 < f2 / f < -2; 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: 0.01 < R3 / R4 < 0.1.

[0009] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 3 < f3 / f < 14.

[0010] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1 < f4 / f < 1.5.

[0011] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 2 < f6 / f < 3.3.

[0012] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.8 < f7 / f < 4.

[0013] Further preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -6 < f8 / f < -1.

[0014] Further preferably, the effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: -10 < f9 / f < -1.

[0015] Compared with the prior art, the optical lens provided by the present invention adopts nine 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 ultra-wide angle, small distortion, miniaturization, and large image plane. Description of the Drawings

[0016] 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 Schematic diagram of the structure of the optical lens in Example 1 of the present invention.

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

[0018] Figure 3 4 is an f-θ distortion curve diagram of the optical lens in Example 1 of the present invention.

[0019] Figure 4 Graph showing the axial aberration of the optical lens in Example 1 of the present invention.

[0020] Figure 5 Graph showing the vertical axis chromatic aberration of the optical lens in Example 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 4 is a field curvature curve diagram of the optical lens in Example 2 of the present invention.

[0023] Figure 8 4 is an f-θ distortion curve diagram of the optical lens in Example 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 4 is an f-θ distortion curve diagram of the optical lens in Example 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] Fig.16 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0032] Fig.17It is a field curvature curve diagram of the optical lens in Example 4 of the present invention.

[0033] Fig.18 4 is an f-θ distortion curve of the optical lens in Example 4 of the present invention.

[0034] Fig.19 4 is an axial aberration curve diagram of the optical lens in Example 4 of the present invention.

[0035] Fig. 20 Graph showing the vertical axis chromatic aberration of the optical lens in Example 4 of the present invention.

[0036] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The optical lens provided by the embodiment of the present invention comprises nine lenses in total, and the optical lens comprises, in order from the object side to the imaging surface along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens.

[0045] In some embodiments, the first lens may have a negative optical power, its object side surface is convex, and its image side surface is concave. The second lens may have a negative optical power, its object side surface is concave, and its image side surface is convex at the near optical axis. The third lens may have a positive optical power, its object side surface is convex, and its image side surface is concave. The fourth lens may have a positive optical power, its object side surface is convex, and its image side surface is convex. The fifth lens may have a positive optical power or a negative optical power, its object side surface is concave, and its image side surface may be concave or convex. The sixth lens may have a positive optical power, its object side surface may be concave or convex, and its image side surface is convex. The seventh lens may have a positive optical power, its object side surface is concave, and its image side surface is convex. The eighth lens may have a negative optical power, its object side surface is concave, and its image side surface is convex at the near optical axis. The ninth lens element may have negative refractive power, its object side surface may be a concave surface or a convex surface, and its image side surface is a concave surface near the optical axis.

[0046] In some embodiments, the optical lens may further include a diaphragm, which may be located between the third lens and the fourth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the image. When the diaphragm is located between the third lens and the fourth lens, it is convenient for the correction of diaphragm aberration.

[0047] In some embodiments, the optical lens may further include a filter, which is disposed between the ninth 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.

[0048] In some embodiments, the combined focal length fa of the first lens, the second lens, and the third lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens satisfy: -1.5 < fa / fb < -0.8. Meeting the above conditions, by reasonably setting the focal length relationship of the lens groups before and after the diaphragm, it helps the smooth transition of light, reduces the difficulty of correcting distortion and chromatic aberration of the rear lenses while ensuring the realization of ultra-large field-of-view imaging, and improves the image quality of the optical imaging lens.

[0049] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5 < TTL / f < 7. Meeting the above conditions can effectively limit the length of the lens and realize the miniaturization of the lens.

[0050] In some embodiments, 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: 1.5 < TTL / IH < 2.3. Meeting the above conditions can better realize the miniaturization of the lens. At the same time, when ensuring the same overall length of the lens, it has a larger image plane and can match a larger-size imaging chip to achieve high-definition imaging.

[0051] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -1.8. Meeting the above conditions can make the first lens have a large negative refractive power, which is beneficial to collecting as much marginal field light as possible into the rear system, realizing the collection of large-angle light, and thus realizing the ultra-wide-angle imaging of the lens.

[0052] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.8 < f1 / f2 < 1. Meeting the above conditions can effectively converge the large range of light entering the system, and at the same time is beneficial to the correction of large-angle aberration by the rear optical system, thus realizing the balance of miniaturization and high pixel of the optical lens.

[0053] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -3 < f2 / f < -2. Meeting the above conditions, the second lens has a negative optical power, which can share the negative optical power at the front end of the optical lens, thus helping to avoid excessive light deflection caused by over-concentration of the optical power of the first lens and reducing the difficulty of chromatic aberration correction of the optical lens.

[0054] In some embodiments, 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: 0.01 < R3 / R4 < 0.1. Meeting the above conditions, by setting the second lens to a concave-convex surface type, it is beneficial to achieve the ultra-wide-angle characteristic, so that more scene information can be obtained, meeting the requirements of large-range detection of the optical lens.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 3 < f3 / f < 14. Meeting the above conditions, the third lens has an appropriate positive optical power, which can converge the light entering the system well, balance the aberration brought by the front lens, and improve the imaging quality of the optical lens.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1 < f4 / f < 1.5; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: -0.5 < R7 / R8 < -0.2. Meeting the above conditions, the light can be further effectively converged, the difficulty of edge field distortion correction can be reduced, ensuring that the lens has a small distortion while achieving a large field of view angle, improving the resolution of the edge field of view, and enabling the lens to have a high imaging quality throughout the field of view.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 2 < f6 / f < 3.3. Meeting the above conditions, it is beneficial to converge the light while correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.8 < f7 / f < 4; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 1.8 < R13 / R14 < 2.8. Meeting the above conditions, the seventh lens can have an appropriate positive optical power, which is beneficial to balance the coma, astigmatism and field curvature of the optical lens, and improve the imaging quality of the optical lens.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -6 < f8 / f < -1; the object-side curvature radius R15 of the eighth lens and the image-side curvature radius R16 of the eighth lens satisfy: 0.2 < R15 / R16 < 0.7. Satisfying the above conditions is beneficial to diverging the light rays in the central field of view to a certain extent, and at the same time, combining with the curvature of the peripheral field of view to reduce the exit angle of the light rays in the peripheral field of view, and improving the relative illumination of the peripheral field of view.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: -10 < f9 / f < -1. Satisfying the above conditions is beneficial to increasing the height of the light rays incident on the imaging surface, increasing the area of the light rays entering the imaging surface, realizing large-format imaging of the lens, and improving the imaging quality of the optical lens.

[0061] In some embodiments, the object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: 3 < R1 / R2 < 4. Satisfying the above conditions, the first lens adopts a meniscus shape, which helps to converge the incident light rays, reduce the aperture of the front lens, facilitate the miniaturization of the front part, and at the same time increase the light flux of the incident light rays, realizing the large-aperture performance of the lens.

[0062] In some embodiments, the object-side curvature radius R5 of the third lens and the image-side curvature radius R6 of the third lens satisfy: 0.3 < R5 / R6 < 1. Satisfying the above conditions is beneficial to better converge the light rays, shorten the distance of the light rays reaching the next lens, and is beneficial to reducing the total length of the optical lens.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 12 < |f5 / f| < 25. Satisfying the above conditions, by reasonably setting the fifth lens to have an appropriate focal length, it is beneficial to balance the astigmatism and field curvature of the optical lens and improve the imaging quality of the optical lens.

[0064] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: 2 < f3 / f4 < 12. Satisfying the above conditions is beneficial to the smooth transition of the light rays, and at the same time can better correct the distortion of the peripheral field of view, reduce the image compression degree of the peripheral field of view, and improve the resolution of the peripheral field of view.

[0065] In some embodiments, the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: 0.5 < f6 / f7 < 1. Satisfying the above conditions is beneficial to the smooth transition of the light rays, and at the same time corrects various aberrations of the optical lens, and improves the imaging quality of the optical lens.

[0066] In some embodiments, the focal length f8 of the eighth lens and the focal length f9 of the ninth lens satisfy: 0.1 < f8 / f9 < 2. Satisfying the above conditions is beneficial to increasing the area of light entering the imaging surface and achieving large target surface imaging of the lens.

[0067] In some embodiments, the effective focal length f of the optical lens and the combined focal length fa of the first lens, the second lens, and the third lens satisfy: -1.5 < fa / f < -0.8. Satisfying the above conditions, by setting the lens group in front of the aperture to have a large negative refractive power, it is beneficial to reduce the astigmatism and field curvature generated by the front-end lens of the optical lens and improve the imaging quality of the optical lens.

[0068] The effective focal length f of the optical lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens satisfy: 0.8 < fb / f < 1.5. Satisfying the above conditions, by reasonably distributing the focal lengths of the lens group behind the aperture, it is beneficial to balance the distortion and astigmatism generated by the front-end lens of the optical lens and improve the imaging quality of the optical lens.

[0069] In some embodiments, the optical lens satisfies the conditional formula: 2.5 mm < f < 3 mm, 15 mm < TTL < 18 mm, 175° < FOV < 190°, Fno < 2.4; 8 mm < IH < 9 mm; where f represents the effective focal length of the optical lens, TTL represents the overall optical length of the optical lens, FOV represents the maximum field of view angle of the optical lens, Fno represents the aperture value of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. Satisfying the above conditions indicates that the optical lens provided by the embodiments of the present invention is beneficial to achieving ultra-wide-angle characteristics, so as to obtain more scene information and meet the requirements of large-range detection of the optical lens; it indicates that the lens has a smaller overall optical length; it is beneficial to improving the light input of the lens, enabling the lens to achieve high-definition imaging even in a dim environment at night; it indicates that the lens has a large imaging surface and can be matched with a larger-size chip to achieve high-definition imaging.

[0070] In some embodiments, the nine lenses in the optical lens can all adopt plastic lenses or adopt a glass-plastic hybrid material matching structure. Preferably, the optical lens of the present invention adopts a nine-piece glass-plastic hybrid matching lens structure. Specifically, the first lens, the third lens, and the fourth lens can adopt glass lenses, and the second lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens are all plastic lenses; adopting a glass-plastic hybrid structure can improve the thermal stability performance, effectively reduce costs, correct aberrations, reduce the volume, and provide an optical lens product with higher cost performance.

[0071] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens may be spherical lenses or aspherical lenses. Compared with spherical structures, aspherical structures can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and reducing the size of lenses, and better realizing miniaturization of lenses. More specifically, in the optical lens provided by the present invention, the first lens, the third lens, and the fourth lens may be spherical lenses, and the second lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens may be aspherical lenses.

[0072] In various embodiments of the present invention, when the lens is an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; 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, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0073] 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.

[0074] Example 1 See also Figure 1 , which is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention, wherein the optical lens 100 includes, in sequence from the object side to the imaging surface S21 along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a filter G1.

[0075] The first lens L1 has negative 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 concave, and its image side surface S4 is convex near the optical axis; 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, its object-side surface S7 is convex, 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 at the near optical axis; The sixth lens L6 has positive refractive power, its object-side surface S11 is concave, and its image-side surface S12 is convex; The seventh lens L7 has positive refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex; The eighth lens L8 has negative refractive power, its object-side surface S15 is concave, and its image-side surface S16 is convex near the optical axis; The ninth lens L9 has negative refractive power, an object-side surface S17 thereof is convex at the near optical axis, and an image-side surface S18 thereof is concave at the near optical axis; The object side surface S19 and the image side surface S20 of the filter G1 are both planes; The imaging surface S21 is a plane.

[0076] The first lens L1, the third lens L3, and the fourth lens L4 are glass spherical lenses; the second lens L2, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are plastic aspherical lenses.

[0077] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0078] Table 1-1 The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0079] Table 1-2 In this embodiment, the field curvature curve, f-θ 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 and Figure 5 shown.

[0080] Figure 2 The field curvature curve in this embodiment 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 field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.1mm, indicating that the optical lens 100 can well correct the field curvature.

[0081] Figure 3The f-θ distortion curve of this embodiment is shown, which represents the distortion of different field angles on the imaging plane, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the field angle (unit: °). It can be seen from the figure that the distortion value is controlled within ±4%, indicating that the optical lens 100 can correct the distortion well.

[0082] Figure 4 The axial aberration curve in this embodiment is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the offset of the axial aberration is controlled within ±0.04mm, indicating that the optical lens 100 can better correct the axial aberration.

[0083] Figure 5 The vertical axis chromatic aberration curve in this embodiment is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.55 μm) at different image heights on the imaging surface, the horizontal axis represents the vertical axis chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5 μm, indicating that the optical lens 100 can correct the vertical axis chromatic aberration well.

[0084] 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 image side surface S10 of the fifth lens L5 is a convex surface; the object side surface S11 of the sixth lens L6 is a convex 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 200 in Example 2 are shown in Table 2-1.

[0086] Table 2-1 The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0087] Table 2-2 In this embodiment, the field curvature curve, f-θ distortion curve, axial aberration curve, and vertical axis chromatic aberration curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Fig. 9 and Fig.10 shown.

[0088] from Figure 7It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 200 can correct the field curvature well.

[0089] from Figure 8 It can be seen that the distortion value is controlled within ±3%, indicating that the optical lens 200 can correct the distortion well.

[0090] 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.

[0091] from Fig.10 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5μm, indicating that the optical lens 200 can correct the vertical axis chromatic aberration well.

[0092] 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 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.

[0093] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0094] Table 3-1 The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0095] Table 3-2 In this embodiment, the field curvature curve, f-θ distortion curve, axial aberration curve, and vertical axis chromatic aberration curve of the optical lens 300 are respectively as follows: Fig.12 , Fig.13 , Fig.14 and Fig.15 shown.

[0096] from Fig.12 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 300 can correct the field curvature well.

[0097] from Fig.13 It can be seen that the distortion value is controlled within ±5%, indicating that the optical lens 300 can correct the distortion well.

[0098] from Fig.14It can be seen that the offset of the axial aberration is controlled within ±0.03 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0099] from Fig.15 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5μm, indicating that the optical lens 300 can correct the vertical axis chromatic aberration well.

[0100] Example 4 See also Fig.16 , shown is a schematic diagram of the structure of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, this embodiment has the following main differences: the fifth lens L5 has positive focal power; the image side surface S10 of the fifth lens L5 is a convex surface; the object side surface S17 of the ninth lens L9 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0101] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0102] Table 4-1 The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0103] Table 4-2 In this embodiment, the field curvature curve, f-θ distortion curve, axial aberration curve, and vertical axis chromatic aberration curve of the optical lens 400 are respectively as follows: Fig.17 , Fig.18 , Fig.19 and Fig. 20 shown.

[0104] from Fig.17 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.1 mm, indicating that the optical lens 400 can correct the field curvature well.

[0105] from Fig.18 It can be seen that the distortion value is controlled within ±4%, indicating that the optical lens 400 can correct the distortion well.

[0106] from Fig.19 It can be seen that the offset of the axial aberration is controlled within ±0.04 mm, indicating that the optical lens 400 can correct the axial aberration well.

[0107] from Fig. 20 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5μm, indicating that the optical lens 400 can correct the vertical axis chromatic aberration well.

[0108] Please refer to Table 5, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0109] Table 5 Compared with the prior art, the optical lens provided by the present invention has at least the following advantages: (1) The optical lens provided by the present invention has a relatively compact structure through a specific surface shape setting and a reasonable optical focal length distribution, which is conducive to the miniaturization of the optical lens; it can achieve an ultra-wide angle of the lens, thereby being able to obtain more scene information and meet the needs of large-range detection of the optical lens.

[0110] (2) The optical lens provided by the present invention has a large image surface, which can be well matched with a large-size chip to ensure good resolution quality; at the same time, it can also reasonably correct the overall aberration of the optical lens, so that the optical lens has small distortion, thereby improving the imaging quality of the optical lens.

[0111] (3) The optical lens provided by the present invention adopts a glass-plastic hybrid structure, which not only makes the lens have good thermal stability, improves the stability of the lens under high and low temperature conditions, but also improves the imaging quality. It also greatly reduces the production cost of the lens, reduces the size of the lens, and better realizes the miniaturization of the lens.

[0112] 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.

[0113] 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 nine lenses, characterized in that: From the object side to the imaging plane along the optical axis, it successively includes: A first lens with a negative focal power, whose object side is convex and whose image side is concave; A second lens with a negative focal power, whose object side is concave and whose image side is convex near the optical axis; A third lens with a positive focal power, whose object side is convex and whose image side is concave; A fourth lens with a positive focal power, whose object side is convex and whose image side is convex; A fifth lens with a focal power, whose object side is concave; A sixth lens with a positive focal power, whose image side is convex; A seventh lens with a positive focal power, whose object side is concave and whose image side is convex; An eighth lens with a negative focal power, whose object side is concave and whose image side is convex near the optical axis; A ninth lens with a negative focal power, whose image side is concave near the optical axis; Among them, the combined focal length fa of the first lens, the second lens and the third lens and the combined focal length fb of the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens and the ninth lens satisfy: -1.5 < fa / fb < -0.

8.

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: 5 < TTL / f < 7; 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: 1.5 < TTL / IH < 2.

3.

3. 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: -2.8 < f1 / f < -1.8; the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: 0.8 < f1 / f2 < 1.

4. 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: -3 < f2 / f < -2; 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: 0.01 < R3 / R4 < 0.

1.

5. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 3 < f3 / f < 14.

6. 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: 1 < f4 / f < 1.

5.

7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 2 < f6 / f < 3.

3.

8. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.8 < f7 / f < 4.

9. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -6 < f8 / f < -1.

10. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: -10 < f9 / f < -1.

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