Optical lens

Abstract

The invention provides an optical lens, which comprises nine lenses from an object side to an imaging surface in sequence along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the object side surface of the second lens is a convex surface; the third lens has positive focal power; the fourth lens has positive focal power, and the object side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface; the seventh lens has negative focal power, and the object side surface of the seventh lens is a concave surface; the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a concave surface; and the object side surface of the ninth lens is a convex surface. The optical lens provided by the invention has one or more advantages of miniaturization, large field angle, large image plane, large aperture, high imaging quality and the like through specific surface shape matching and reasonable focal power distribution.

Description

Technical Field

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

[0002] In the field of modern motion image capture, high-performance portable optical systems are a core requirement. Most of the current action camera lenses on the market adopt large-aperture and ultra-wide-angle designs to adapt to high-speed motion scenes and extreme environment shooting. However, these traditional optical structures generally have problems such as a decline in imaging quality in low-light environments and insufficient dynamic range. At the same time, in order to improve the anti-shake performance, a complex optical compensation mechanism is often adopted, resulting in an increase in the volume and weight of the lens module, which not only restricts the adaptability of the device to extreme motion scenes but also significantly increases the production and maintenance costs. At the same time, as the field of view angle of the lens increases, it becomes difficult to correct system aberrations, resulting in a decline in imaging quality; the relative aperture of the lens is small, the light transmission performance is poor, and it cannot adapt to a darker environment; and the existing lens imaging target surface is small, making it difficult to meet market demands. Summary of the Invention

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

[0004] The technical solution adopted by the present invention is as follows: An optical lens, comprising a total of nine lenses, which sequentially include, along the optical axis from the object side to the imaging surface: A first lens with a negative optical power, whose object side is concave and whose image side is concave; A second lens with a positive optical power, whose object side is convex; A third lens with a positive optical power; A fourth lens with a positive optical power, whose object side is convex; A fifth lens with a negative optical power, whose object side is convex and whose image side is concave; A sixth lens with a positive optical power, whose object side is convex and whose image side is convex; A seventh lens with a negative optical power, whose object side is concave; An eighth lens with a negative optical power, whose object side is concave and whose image side is concave; A ninth lens with a positive optical power, whose object side is convex.

[0005] 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 < 6.5; 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: 2.1 < TTL / IH < 2.5.

[0006] More preferably, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 60° < FOV / Fno < 70°; the true image height IH corresponding to the maximum field of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 5.5 < IH / EPD < 6.5.

[0007] More preferably, the true image height IH corresponding to the maximum field of view of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.7; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.3 < BFL / f < 0.6.

[0008] More preferably, the clear aperture d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field of view of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.21 < d1 / (IH / 2) / tan(FOV / 2) < 0.26; the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f56789 of the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens satisfy: 0.07 < f1234 / f56789 < 0.72.

[0009] More preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.7 < f1 / f < -1.5; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -24 < R1 / f < -2.5; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.8 < R2 / f < 1.2.

[0010] More preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 11 < f3 / f < 32; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.29 < R5 / R6 < 1.02.

[0011] More preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -5.8 < f8 / f < -3.7; the curvature radius R15 of the object side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -8.5 < R15 / f < -4.3; the curvature radius R16 of the image side surface of the eighth lens and the effective focal length f of the optical lens satisfy: 4.3 < R16 / f < 5.

[0012] Further preferably, the effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: 38 < f9 / f < 51; the radius of curvature R17 of the object side surface of the ninth lens and the effective focal length f of the optical lens satisfy: 1.5 < R17 / f < 36.

[0013] Further preferably, the radius of curvature R1 of the object side surface of the first lens and the radius of curvature R2 of the image side surface of the first lens satisfy: 0.2 < (R1 + R2) / (R1 - R2) < 1.

[0014] The optical lens provided by the present invention uses nine lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, enabling the lens to have one or more advantages such as miniaturization, large field of view, large image plane, large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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, where: Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0016] Figure 2 is an MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0017] Figure 3 is a field curvature curve graph of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 4 is an F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 5 is an axial aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 6 is a lateral chromatic aberration curve graph of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 7 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 8 is an MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0023] Figure 9 is a field curvature curve graph of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 10It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 11 It is the axial aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 12 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 2 of the present invention.

[0027] Figure 13 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0028] Figure 14 It is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 15 It is the field curvature curve graph of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 16 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 17 It is the axial aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 18 It is the lateral chromatic aberration curve graph of the optical lens in Embodiment 3 of the present invention.

[0033] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0034] To better understand the present application, more detailed descriptions of various aspects of the present application will be made 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 do not 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.

[0035] It should be noted that in this specification, the expressions such as first, second, third, etc. are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0036] In the drawings, for ease of explanation, the thickness, dimensions, and shape of the lenses are slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are presented by way of example. That is, the spherical or aspherical shapes are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not drawn to an exact scale.

[0037] In this document, 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 to be photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging surface is called the image side surface of the lens.

[0038] It should also be understood that the terms "comprises", "comprising", "has", "including", and / or "including having", when used in this specification, denote the presence of the stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. In addition, when an expression such as "at least one of..." appears after a list of listed features, it modifies the entire list of listed features, rather than individual elements in the list. In addition, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0039] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0040] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0041] The optical lens provided by the embodiment of the present invention has a total of nine lenses, which are, in order from the object side to the imaging surface along the optical axis, 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.

[0042] In some embodiments, the first lens may have a negative focal power, with its object side being concave and its image side being concave. The second lens may have a positive focal power, with its object side being convex and its image side being either concave or convex. The third lens may have a positive focal power, with its object side being either concave or convex and its image side being either concave or convex. The fourth lens may have a positive focal power, with its object side being convex and its image side being either concave or convex. The fifth lens may have a negative focal power, with its object side being convex and its image side being concave. The sixth lens may have a positive focal power, with its object side being convex and its image side being convex. The seventh lens may have a negative focal power, with its object side being concave and its image side being either concave or convex. The eighth lens may have a negative focal power, with its object side being concave and its image side being concave. The ninth lens may have a positive focal power, with its object side being convex and its image side being either concave or convex.

[0043] In some embodiments, the optical lens may further include a diaphragm, which may be located between the fourth lens and the fifth lens. It can be understood that the diaphragm is used to limit the amount of incident light to change the brightness of the imaging. Additionally, when the diaphragm is located between the fourth lens and the fifth lens, the diaphragm can reasonably distribute the functions of the first lens to the ninth lens. For example, the first lens, the second lens, the third lens, and the fourth lens can be used to receive light to a greater extent, and the fifth lens to the ninth lens can be used to correct aberrations, which is beneficial to balancing the structure of the entire optical system. Furthermore, when the diaphragm is located between the fourth lens and the fifth lens, it is convenient to correct the diaphragm aberration.

[0044] 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.

[0045] In some embodiments, the fifth lens and the sixth lens may be glued together to form a cemented lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0046] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5 < TTL / f < 6.5. Meeting the above range can effectively limit the length of the lens, which is beneficial to realizing the miniaturization of the optical lens. More specifically, 5.2 < TTL / f < 6.08.

[0047] 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: 2.1 < TTL / IH < 2.5. Meeting the above range ensures that, with the same total length of the lens, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging, and better realizes the balance between the small total length and the large image plane of the lens. More specifically, 2.25 < TTL / IH < 2.4.

[0048] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 60° < FOV / Fno < 70°. Meeting the above range limits that the optical lens has an appropriate field of view angle and aperture value, can collect light at large angles and obtain good imaging quality. More specifically, 65.2° < FOV / Fno < 65.9°.

[0049] 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: 5.5 < IH / EPD < 6.5. Meeting the above range can increase the width of the light beam incident on the optical lens, so that the brightness at the image plane of the optical lens is improved and vignetting is avoided. More specifically, 5.61 < IH / EPD < 6.24.

[0050] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.7. Meeting the above range controls the image height and focal length of the optical lens within a reasonable range, which helps the optical lens to have the characteristic of a large image plane and improves the imaging quality. More specifically, 2.3 < IH / f < 2.55.

[0051] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.3 < BFL / f < 0.6. Meeting the above range limits that the optical lens has an appropriate back focus, which is convenient for reasonably arranging the positions of each lens and reduces the processing and assembly difficulty. More specifically, 0.35 < BFL / f < 0.57.

[0052] In some embodiments, the clear aperture d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.21 < d1 / (IH / 2) / tan(FOV / 2) < 0.26. Meeting the above range can have a small front aperture while meeting the requirements of the optical lens having a large field of view angle and a large image plane.

[0053] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f56789 of the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens satisfy: 0.07 < f1234 / f56789 < 0.72. The combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the effective focal length f of the optical lens satisfy: 1.3 < f1234 / f < 2.7; the combined focal length f56789 of the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens and the effective focal length f of the optical lens satisfy: 3.5 < f56789 / f < 18. Satisfying the above ranges and reasonably setting the focal lengths of the lens groups before and after the aperture is beneficial to balancing various aberrations generated by the lens group in front of the aperture and improving the overall imaging quality. More specifically, 1.4 < f1234 / f < 2.63; 3.69 < f56789 / f < 17.55.

[0054] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.7 < f1 / f < -1.5; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -24 < R1 / f < -2.5; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.8 < R2 / f < 1.2. Satisfying the above ranges and setting the first lens to have negative refractive power and a biconcave shape is beneficial for the first lens to receive a larger angle of light and collect as much light as possible into the subsequent optical system, achieving a large field of view while increasing the light flux. More specifically, -1.67 < f1 / f < -1.55; -23.15 < R1 / f < -2.7; 0.84 < R2 / f < 1.12.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 11 < f3 / f < 32; the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: 0.29 < R5 / R6 < 1.02. Satisfying the above ranges can make the third lens have appropriate positive optical power and a meniscus shape, which is beneficial for improving the light converging ability of the optical lens, and at the same time can balance various aberrations generated by the optical lens and improve the imaging quality of the optical lens. More specifically, 11.79 < f3 / f < 31.79.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: -5.8 < f8 / f < -3.7; the object-side curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -8.5 < R15 / f < -4.3; the image-side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: 4.3 < R16 / f < 5. Meeting the above ranges and setting the eighth lens to have a negative refractive power and a double-concave shape is beneficial to increasing the divergence degree of light, increasing the area of light entering the imaging surface, achieving large-format imaging of the lens, and improving the imaging quality of the optical lens. More specifically, -5.54 < f8 / f < -3.88; -8.06 < R15 / f < -4.42; 4.45 < R16 / f < 4.88.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f9 of the ninth lens satisfy: 38 < f9 / f < 51; the object-side curvature radius R17 of the ninth lens and the effective focal length f of the optical lens satisfy: 1.5 < R17 / f < 36. Meeting the above ranges can make the eighth lens have a positive optical power and a convex object side, control the light trend smoothly, reduce the angle between the chief ray of the marginal field of view and the optical axis, and improve the aberration by reducing the spot diameter. More specifically, 38.32 < f9 / f < 50.82; 1.59 < R17 / f < 35.71.

[0058] 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: 0.2 < (R1 + R2) / (R1 - R2) < 1. Meeting the above ranges can control the light direction, reduce spherical aberration, correct coma, increase light utilization rate, and improve stability. More specifically, 0.41 < (R1 + R2) / (R1 - R2) < 0.94.

[0059] In some embodiments, the overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the ninth lens along the optical axis respectively satisfy: 0.49 < ∑CT / TTL < 0.55. Meeting the above ranges can effectively compress the overall length of the optical lens, and is beneficial to the structural design and production process of the optical lens.

[0060] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the ninth lens along the optical axis respectively and the effective focal length f of the optical lens satisfy: 2.81 < ΣCT / f < 3.02. Meeting the above ranges can effectively correct the field curvature and distortion of the optical lens, and improve the imaging quality of the optical lens.

[0061] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 4.8 < f2 / f < 9. Meeting the above range defines that the second lens has an appropriate positive optical power, which has the effect of converging light rays, reducing the height of peripheral light rays, and is beneficial to reducing the aperture of the rear lens. More specifically, 4.01 < f2 / f < 8.91.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.2 < f4 / f < 2.9. Meeting the above range sets the fourth lens to have a positive refractive power, which is beneficial to converging light rays while correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens. More specifically, 2.32 < f4 / f < 2.8.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.9 < f5 / f < -1.2. Meeting the above range can make the fifth lens have an appropriate negative optical power, which can balance various aberrations generated by the optical lens and improve the imaging quality of the optical lens. More specifically, -1.8 < f5 / f < -1.29.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.8 < f6 / f < 1; the curvature radius R11 of the object side surface of the sixth lens and the effective focal length f of the optical lens satisfy: 0.55 < R11 / f < 0.65; the curvature radius R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -5.7 < R12 / f < -3.3. Meeting the above range defines that the sixth lens has a positive optical power and a suitable surface shape, which is beneficial to light convergence. And the cooperation of the sixth lens with positive optical power and the fifth lens with negative optical power can adjust the optical path difference between different fields of view, improve the resolution, and is beneficial to making the light enter the rear lens smoothly, further reducing the field curvature and correcting the off-axis point aberration of the optical lens. More specifically, 0.86 < f6 / f < 0.95; 0.56 < R11 / f < 0.63; -5.64 < R12 / f < -3.32.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: -8.2 < f7 / f < -3.6; the curvature radius R13 of the object side surface of the seventh lens and the effective focal length f of the optical lens satisfy: -4 < R13 / f < -2.9. Meeting the above range sets the seventh lens to have a negative refractive power and the object side surface to be concave, which can effectively balance various aberrations generated by the front lens group. More specifically, -7.96 < f7 / f < -4.8; -3.9 < R13 / f < -2.93.

[0066] In some embodiments, the optical lens satisfies the following conditional expressions: 3.7 mm < f < 4.6 mm; 1.5 mm < EPD < 1.8 mm; 20 mm < TTL < 25 mm; 2.2 < Fno < 2.6; 30° < CRA < 40°; 1.3 mm < BFL < 2.4 mm; 150° < FOV < 170°; 9 mm < IH < 11 mm. In the above conditional expressions, 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 chief ray angle of incidence 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 ranges, the optical lens has at least one or more advantages such as miniaturization, large image plane, large aperture, and large field of view angle. More specifically, 3.93 mm < f < 4.34 mm; 1.59 mm < EPD < 1.79 mm; 22.54 mm < TTL < 23.88 mm; 2.42 < Fno < 2.46; 31.39° < CRA < 36.86°; 1.45 mm < BFL < 2.21 mm; 159° < FOV < 161°; 9.9 mm < IH < 10.1 mm.

[0067] 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, the geometric chromatic aberration of the optical system can be effectively corrected due to the low dispersion characteristic of the glass itself. The optical lens of the present invention adopts a lens structure with nine pieces of glass-plastic hybrid combination, which can improve the thermal stability performance. Specifically, the seventh lens is a plastic lens; the eighth lens is a plastic or glass lens; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the ninth lens are all glass lenses; adopting a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce the volume, and provide an optical lens product with higher cost performance.

[0068] 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 can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, in the optical lens provided by the present invention, the first lens, the second lens, the seventh lens, the eighth lens, and the ninth lens can adopt aspherical lenses, and the third lens, the fourth lens, the fifth lens, and the sixth lens can adopt spherical lenses.

[0069] 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 equation: ; where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, and F are the surface coefficients of the fourth, sixth, eighth, tenth, and twelfth orders, respectively.

[0070] The present invention will be further described in multiple embodiments below. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are somewhat different. For specific differences, please refer to the parameter tables of each embodiment. The following embodiments are only the preferred embodiments of the present invention, but the embodiments of the present invention are not limited only by the following embodiments. Any other changes, substitutions, combinations, or simplifications made without departing 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.

[0071] Embodiment 1 Please refer to Figure 1 , which shows a schematic structural diagram of an optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 sequentially includes, along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a diaphragm ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, and a filter G1.

[0072] Among them, the first lens L1 has a negative optical power, its object side surface S1 is a concave surface, and its image side surface S2 is a concave surface; The second lens L2 has a positive optical power, its object side surface S3 is a convex surface, and its image side surface S4 is a concave surface; The third lens L3 has a positive optical power, its object side surface S5 is a convex surface, and its image side surface S6 is a concave surface; The fourth lens L4 has a positive optical power, its object side surface S7 is a convex surface, and its image side surface S8 is a convex surface; The fifth lens L5 has a negative optical power, its object side surface S9 is a convex surface, and its image side is a concave surface; The sixth lens L6 has a positive optical power, its object side is a convex surface, and its image side surface S11 is a convex surface; The fifth lens L5 and the sixth lens L6 form a cemented lens group with a positive optical power, that is, the cemented surface of the image side surface of the fifth lens L5 and the object side surface of the sixth lens L6 is S10; The seventh lens L7 has a negative optical power, its object side surface S12 is a concave surface, and its image side surface S13 is a convex surface; The eighth lens L8 has a negative optical power, its object side S14 is concave, and its image side S15 is concave; The ninth lens L9 has a positive optical power, its object side S16 is convex, and its image side S17 is concave; Both the object side S18 and the image side S19 of the filter G1 are flat; The imaging surface S20 is flat.

[0073] The seventh lens L7 and the eighth lens L8 are plastic aspherical lenses; the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are glass spherical lenses; the first lens L1, the second lens L2, and the ninth lens L9 are glass aspherical lenses.

[0074] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0075] Table 1-1 The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0076] Table 1-2 In this embodiment, the MTF curve graph, field curvature curve graph, F-Tan(Theta) distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 shown.

[0077] Figure 2 shows the MTF (Modulation Transfer Function) curve graph of Embodiment 1, which represents the modulation of the lens imaging at different spatial frequencies in each field of view. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.25 in the entire field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0078] Figure 3 shows the field curvature curve of Embodiment 1, which represents the bending degree of light rays of different wavelengths in 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 of view 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 ±0.02 mm, indicating that the optical lens can well correct the field curvature.

[0079] Figure 4 Shows the F-Tan(Theta) distortion curve of Embodiment 1, which represents the F-Tan(Theta) distortion of light rays with different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tan(Theta) distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the F-Tan(Theta) distortion of the optical lens is controlled within -80% to 0, and the image compression in the edge angle region is relatively gentle, effectively improving the clarity of the expanded image.

[0080] Figure 5 Shows the axial aberration curve graph of the optical lens 100 in this embodiment, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens 100 can correct the axial aberration well.

[0081] Figure 6 Shows the lateral chromatic aberration curve graph of the optical lens 100 in this embodiment, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.522 μm) at different image heights on the imaging plane. The horizontal axis represents the lateral 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 lateral chromatic aberration of the longest wavelength and the shortest wavelength is controlled within 0 to 3 μm, indicating that the optical lens can correct the chromatic aberration well.

[0082] Embodiment 2 Please refer to Figure 7 , which shows the structural schematic diagram of the optical lens 200 provided in Embodiment 2 of the present invention. Compared with Embodiment 1, the main differences are as follows: The image side S4 of the second lens L2 is a convex surface; the object side S5 of the third lens L3 is a concave surface; the image side S6 of the third lens L3 is a convex surface; the image side S13 of the seventh lens L7 is a concave surface; the eighth lens L8 uses a glass aspherical lens; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0083] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0084] Table 2-1 The surface type parameters of the aspherical lens of the optical lens 200 in Embodiment 2 are shown in Table 2-2.

[0085] Table 2-2 In this embodiment, the MTF curve graph, field curvature curve graph, F-Tan(Theta) distortion curve graph, axial aberration curve graph, and lateral chromatic aberration curve graph of the optical lens 200 are respectively as follows Figure 8 , Figure 9 , Figure 10 , Figure 11 and Figure 12 shown.

[0086] It can be seen from Figure 8 that the MTF value of this embodiment is above 0.4 within the entire field of view. In the range of 0 - 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0087] It can be seen from Figure 9 that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.01 mm, indicating that the optical lens can well correct the field curvature.

[0088] It can be seen from Figure 10 that the F-Tan(Theta) distortion of the optical lens is controlled within -80% to 0, and the image compression in the edge angle region is relatively gentle, effectively improving the clarity of the unfolded image.

[0089] It can be seen from Figure 11 that the offset of the axial aberration is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens can better correct the axial aberration.

[0090] It can be seen from Figure 12 that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within -0.5 μm to 1.5 μm, indicating that the optical lens can better correct the chromatic aberration.

[0091] Embodiment 3 Please refer to Figure 13 , which shows the structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present invention. Compared with Embodiment 1, the main differences are as follows: The image side surface S4 of the second lens L2 is a convex surface; the object side surface S5 of the third lens L3 is a concave surface; the image side surface S6 of the third lens L3 is a convex surface; the image side surface S8 of the fourth lens L4 is a concave surface; the image side surface S17 of the ninth lens L9 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0092] The relevant parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0093] Table 3-1 The surface parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0094] Table 3-2 In this embodiment, the MTF curve graph, field curvature graph, F-Tan(Theta) distortion graph, axial aberration graph, and lateral chromatic aberration graph of the optical lens 300 are respectively as Figure 14 , Figure 15 , Figure 16 , Figure 17 and Figure 18 shown.

[0095] From Figure 14 it can be seen that the MTF value of this embodiment is above 0.4 within the entire field of view. In the range of 0 - 160 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and it has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0096] From Figure 15 it can be seen that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.02 mm, indicating that the optical lens can well correct the field curvature.

[0097] From Figure 16 it can be seen that the F-Tan(Theta) distortion of the optical lens is controlled within -80% to 0, and the image compression in the edge angle region is relatively gentle, effectively improving the clarity of the unfolded image.

[0098] From Figure 17 it can be seen that the offset of the axial aberration is controlled within -0.01 mm to 0.02 mm, indicating that the optical lens can well correct the axial aberration.

[0099] From Figure 18 it can be seen that the lateral chromatic aberration between the longest wavelength and the shortest wavelength is controlled within 0 - 2 μm, indicating that the optical lens can well correct the chromatic aberration.

[0100] Please refer to Table 4 for 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 true image height IH corresponding to the maximum field of view angle, the maximum field of view angle FOV, and the values corresponding to each conditional formula in each embodiment.

[0101] Table 4 In summary of the above embodiments, the optical lens provided by the present invention uses nine lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberrations, enhance the imaging quality of the optical lens, and endow the lens with one or more advantages such as miniaturization, large field of view, large image plane, large aperture, and high imaging quality.

[0102] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0103] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent of the present invention shall be subject to the appended claims.

Claims

1. An optical lens, comprising nine lenses, characterized in that: 依次包括从物侧到成像面沿光轴的部分: 第一透镜,具有负光焦度,其物侧面为凹面,像侧面为凹面; 第二透镜,具有正光焦度,其物侧面为凸面; 第三透镜,具有正光焦度; 第四透镜,具有正光焦度,其物侧面为凸面; 第五透镜,具有负光焦度,其物侧面为凸面,像侧面为凹面; 第六透镜,具有正光焦度,其物侧面为凸面,像侧面为凸面; 第七透镜,具有负光焦度,其物侧面为凹面; 第八透镜,具有负光焦度,其物侧面为凹面,像侧面为凹面; 第九透镜,具有正光焦度,其物侧面为凸面。 2. The optical lens according to claim 1, characterized in that: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5 < TTL / f < 6.5; 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: 2.1 < TTL / IH < 2.

5.

3. The optical lens according to claim 1, characterized in that: The maximum field of view angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 60° < FOV / Fno < 70°; 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: 5.5 < IH / EPD < 6.

5.

4. The optical lens according to claim 1, characterized in that: The true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.7; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.3 < BFL / f < 0.

6.

5. The optical lens according to claim 1, characterized in that: The clear aperture d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.21 < d1 / (IH / 2) / tan(FOV / 2) < 0.26; the combined focal length f1234 of the first lens, the second lens, the third lens, and the fourth lens and the combined focal length f56789 of the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens satisfy: 0.07 < f1234 / f56789 < 0.

72.

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: -1.7 < f1 / f < -1.5; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -24 < R1 / f < -2.5; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.8 < R2 / f < 1.

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 f3 of the third lens satisfy: 11 < f3 / f < 32; the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: 0.29 < R5 / R6 < 1.

02.

8. 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: -5.8 < f8 / f < -3.7; the object-side curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -8.5 < R15 / f < -4.3; the image-side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: 4.3 < R16 / f < 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 f9 of the ninth lens satisfy: 38 < f9 / f < 51; the object-side curvature radius R17 of the ninth lens and the effective focal length f of the optical lens satisfy: 1.5 < R17 / f < 36.

10. The optical lens according to claim 1, characterized in that: The object-side curvature radius R1 of the first lens and the image-side curvature radius R2 of the first lens satisfy: 0.2 < (R1 + R2) / (R1 - R2) < 1.

Images