Optical lens

Abstract

The invention provides an optical lens, which comprises six lenses which sequentially comprise 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 from an object side to an image side along an optical axis, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has negative focal power; and 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. According to the optical lens provided by the invention, the imaging quality of the optical lens can be improved, the aberration can be reduced, the imaging quality of the optical lens can be improved, and the lens has one or more advantages of miniaturization, large target surface, large aperture, large field angle, high imaging quality and the like.

Description

Technical Field

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

[0002] With the continuous improvement of people's requirements for driving experience, on-vehicle application optical lenses are increasingly used in intelligent driving, and the status of on-vehicle optical lenses in the automotive-related industry is continuously rising.

[0003] An electronic rearview mirror is an indirect vision device that obtains a specified field of view through a system composed of a camera and a monitor. It includes electronic devices such as a high-definition camera, a digital vision processing system, a safety system, and a liquid crystal display, and is a new type of rearview mirror that can replace traditional rearview mirrors. Generally, an electronic rearview mirror is designed with a main lens and a wide-angle lens, and presents an image through a display screen, which can provide a wider field of view, eliminate blind spots, help the driver better understand the surrounding environment, and reduce the occurrence of accidents. In addition to requiring the lens to have a thin, light, short, and small shape and have characteristics such as high pixels and high resolution, the existing lenses of electronic rearview mirrors also require the optical lens to be able to clearly image under low illuminance conditions. Therefore, it is necessary to develop an optical lens with good imaging effects. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an optical lens, which has the advantage of excellent imaging quality.

[0005] The technical solution adopted by the present invention is as follows: An optical lens, comprising a total of six lenses, which sequentially include from the object side to the imaging surface along the optical axis: A first lens with negative optical power, the object side surface of which is concave and the image side surface of which is concave; A second lens with positive optical power, the object side surface of which is convex and the image side surface of which is concave; A third lens with positive optical power, the object side surface of which is convex; A fourth lens with positive optical power, the object side surface of which is concave and the image side surface of which is convex; A fifth lens with negative optical power; A sixth lens with positive optical power, the object side surface of which is convex and the image side surface of which is convex; Wherein, 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: -0.1 < (R7 - R8) / (R7 + R8) < 1; The curvature radius R1 of the object side surface of the first lens and the curvature radius R2 of the image side surface of the first lens satisfy: -0.6 < (R1 + R2) / (R1 - R2) < 0.9.

[0006] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < TTL / f < 2.7; 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 true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.7 < IH / EPD < 3.2; the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.1 < IH / f < 1.8.

[0008] Further preferably, the half-aperture d1 of the object side of the first lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.77 < d1 / (IH / 2) / tan(FOV / 2) < 1.81; the optical lens further includes a diaphragm, the diaphragm is located between the third lens and the fourth lens or between the second lens and the third lens, and the combined focal length f_after of the lenses behind the diaphragm and the effective focal length f of the optical lens satisfy: 0.7 < f_after / f < 2.

[0009] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -0.8; the radius of curvature R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -9 < R1 / f < -1.1; the radius of curvature R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: 0.6 < R2 / f < 5.9.

[0010] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.8 < f2 / f < 11; the radius of curvature R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: 1.2 < R3 / f < 2.5; the radius of curvature R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: 2.1 < R4 / f < 10.

[0011] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.7 < f3 / f < 2.2; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.4 < f5 / f < -0.6.

[0012] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.8 < f4 / f < 25; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -1; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -0.4.

[0013] Further preferably, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.6 < f6 / f < 10; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.5 < R11 / f < 12.4; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -10.5 < R12 / f < -0.6.

[0014] Further preferably, the object-side curvature radius R3 of the second lens and the image-side curvature radius R4 of the second lens satisfy: -0.8 < (R3 - R4) / (R3 + R4) < -0.1; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: -0.2 < (R11 + R12) / (R11 - R12) < 0.8.

[0015] The optical lens provided by the present invention uses six 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, improve the imaging quality of the optical lens, and enable the lens to have one or more advantages such as miniaturization, large target surface, large aperture, large field of view angle, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 2 is a graph of F-Tan(Theta) distortion of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 is an MTF graph of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0020] Figure 5It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 2 of the present invention.

[0021] Figure 6 It is the MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0022] Figure 7 It is the structural schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0023] Figure 8 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 3 of the present invention.

[0024] Figure 9 It is the MTF curve graph of the optical lens in Embodiment 3 of the present invention.

[0025] Figure 10 It is the structural schematic diagram of the optical lens in Embodiment 4 of the present invention.

[0026] Figure 11 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 4 of the present invention.

[0027] Figure 12 It is the MTF curve graph of the optical lens in Embodiment 4 of the present invention.

[0028] Figure 13 It is the structural schematic diagram of the optical lens in Embodiment 5 of the present invention.

[0029] Figure 14 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 5 of the present invention.

[0030] Figure 15 It is the MTF curve graph of the optical lens in Embodiment 5 of the present invention.

[0031] Figure 16 It is the structural schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0032] Figure 17 It is the F-Tan(Theta) distortion curve graph of the optical lens in Embodiment 6 of the present invention.

[0033] Figure 18 It is the MTF curve graph of the optical lens in Embodiment 6 of the present invention.

[0034] The following specific embodiments will further illustrate the present invention in combination with the above-mentioned drawings. Specific Embodiments

[0035] To better understand the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of 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.

[0036] 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.

[0037] In the drawings, for ease of illustration, the thickness, dimensions, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only examples and are not drawn to an exact scale.

[0038] 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.

[0039] It should also be understood that the terms "comprises", "comprising", "has", "including", and / or "containing", 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 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 modifying an individual element 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.

[0040] 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.

[0041] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments 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.

[0042] The optical lens provided by the embodiment of the present invention has a total of six 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, and the sixth lens.

[0043] In some embodiments, the first lens may have a negative optical power, its object side is concave, and its image side is concave. The second lens may have a positive optical power, its object side is convex, and its image side is concave. The third lens may have a positive optical power, its object side is convex, and its image side may be concave or convex. The fourth lens may have a positive optical power, its object side is concave, and its image side is convex. The fifth lens may have a negative optical power, its object side may be concave or convex, and its image side may be concave or convex. The sixth lens may have a positive optical power, its object side is convex, and its image side is convex.

[0044] In some embodiments, the optical lens may further include a diaphragm, and the diaphragm may be located between the third lens and the fourth lens or between the second lens and the third 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 or between the second lens and the third lens, it is convenient for correcting the diaphragm aberration.

[0045] In some embodiments, the optical lens may further include a filter, and the filter is disposed between the sixth lens and the imaging surface. The filter is used to filter out interfering light to prevent the interfering light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0046] In some embodiments, the curvature radius R7 of the object side of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: -0.1 < (R7 - R8) / (R7 + R8) < 1. Meeting the above range, by controlling the fourth lens to have a suitable surface shape, it is beneficial to strengthen the correction of higher-order aberrations and reduce the attenuation degree of the relative illuminance of the optical lens. At the same time, the fourth lens adopts a meniscus shape, which is beneficial to correcting the distortion of the optical lens and improving the imaging quality of the optical lens. More specifically, -0.03 < (R7 - R8) / (R7 + R8) < 0.93.

[0047] In some embodiments, 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: -0.6 < (R1 + R2) / (R1 - R2) < 0.9. Meeting the above range can make the collected light enter the rear optical system in a divergent form as much as possible, and at the same time effectively reduce the angle between the light incident on the edge field of view and the object side surface of the first lens, improving the relative illumination at the edge of the overall lens. More specifically, -0.56 < (R1 + R2) / (R1 - R2) < 0.86.

[0048] In some embodiments, the overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < TTL / f < 2.7. Meeting the above range can effectively limit the length of the lens, which is beneficial to the miniaturization of the optical lens. More specifically, 2.51 < TTL / f < 2.68.

[0049] 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 range ensures that, with the same overall 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 overall length and the large image plane of the lens. More specifically, 1.59 < TTL / IH < 2.25.

[0050] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.7 < IH / EPD < 3.2. Meeting the above range is beneficial to increasing the light passing amount, making the brightness of the peripheral field of view and the central field of view more uniform. More specifically, 1.79 < IH / EPD < 2.97.

[0051] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 1.1 < IH / f < 1.8. 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 improve the imaging quality. More specifically, 1.12 < IH / f < 1.66.

[0052] In some embodiments, the half-aperture d1 of the light passing through 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: 0.77 < d1 / (IH / 2) / tan(FOV / 2) < 1.81. 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 f_back of the lenses located behind the aperture and the effective focal length f of the optical lens satisfy: 0.7 < f_back / f < 2. Meeting the above range and reasonably setting the focal lengths of the lens groups before and after the aperture is beneficial to balancing various aberrations of the system and improving the overall imaging quality. More specifically, 0.7 < f_back / f < 1.93.

[0054] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 < f1 / f < -0.8; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -9 < R1 / f < -1.1; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 0.6 < R2 / f < 5.9. Meeting the above range and setting the first lens to have a negative refractive power and a suitable surface shape is beneficial for the first lens to accommodate a larger angle of light and collect as much light as possible into the rear optical system, achieving a large field of view while increasing the light flux. More specifically, -2.29 < f1 / f < -0.91; -8.62 < R1 / f < -1.24; 0.66 < R2 / f < 5.41.

[0055] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.8 < f2 / f < 11; the curvature radius R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 1.2 < R3 / f < 2.5; the curvature radius R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 2.1 < R4 / f < 10; 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: -0.8 < (R3 - R4) / (R3 + R4) < -0.1. Meeting the above range and defining the second lens to have an appropriate positive optical power and a suitable surface shape has the effect of converging light, enabling the diverging light to smoothly enter the rear optical system, depressing the height of the peripheral light, and being beneficial for reducing the aperture of the rear lens. More specifically, 1.97 < f2 / f < 10.24; 1.3 < R3 / f < 2.37; 2.29 < R4 / f < 9.03; -0.76 < (R3 - R4) / (R3 + R4) < -0.14.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.7 < f3 / f < 2.2. Meeting the above range and defining the third lens to have an appropriate positive optical power is beneficial for the convergence of light, can effectively correct the distortion of the edge field of view, reduce the degree of deformation of the edge of the captured image, and improve the image quality. More specifically, 0.77 < f3 / f < 2.06.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.4 < f5 / f < -0.6. Meeting the above range makes the light rays in the marginal field of view show an upward trend, which is beneficial for the image points on the imaging surface to be away from the optical axis, so as to facilitate achieving the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolution ability of the optical lens. More specifically, -1.24 < f5 / f < -0.69.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.8 < f4 / f < 25; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -1; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -0.4. Meeting the above range is beneficial for the convergence of light rays, sharing the positive optical power of the second lens and the third lens, avoiding excessive light ray deflection, and better achieving high-quality imaging of the lens. More specifically, 0.81 < f4 / f < 23.27; -14.65 < R7 / f < -1.09; -2.39 < R8 / f < -0.45.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.6 < f6 / f < 10; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.5 < R11 / f < 12.4; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -10.5 < R12 / f < -0.6; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: -0.2 < (R11 + R12) / (R11 - R12) < 0.8. Meeting the above range defines that the sixth lens has positive optical power and a suitable surface shape, which is beneficial for light ray convergence, making the light ray trend transition smoothly to the rear, reducing the height of the light rays incident on the rear, slowing down the upward trend of the light rays, avoiding the light energy loss caused by the excessive main light ray angle of the large field of view light rays reaching the imaging surface, facilitating the improvement of the illuminance of the marginal field of view, and being beneficial for achieving a short optical total length. More specifically, 0.67 < f6 / f < 9.08; 0.56 < R11 / f < 11.33; -9.88 < R12 / f < -0.65; -0.15 < (R11 + R12) / (R11 - R12) < 0.75.

[0060] In some embodiments, the effective focal length f of the optical lens, the true image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0.79 < (IH / 2) / (f × Tan(FOV / 2)) < 1.13. Meeting the above range controls the distortion of the optical lens within a reasonable range.

[0061] In some embodiments, the maximum field of view FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 35° < FOV / Fno < 42°. Meeting the above range defines that the optical lens has a suitable field of view and aperture value, can collect light at a large angle, and obtain good imaging quality. More specifically, 37.7° < FOV / Fno < 40.34°.

[0062] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.18 < BFL / f < 0.92. Meeting the above range defines that the optical lens has a suitable back focus, which facilitates the reasonable arrangement of the positions of each lens and reduces the processing and assembly difficulty.

[0063] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis satisfy: 0.51 < ∑CT / TTL < 0.72. Meeting the above range and reasonably configuring the total optical length of the optical lens and the sum of the thicknesses of each lens contribute to achieving high pixel characteristics and improving the imaging quality of the optical lens.

[0064] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the sixth lens along the optical axis and the effective focal length f of the optical lens satisfy: 1.37 < ΣCT / f < 1.79. Meeting the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens.

[0065] In some embodiments, the optical lens satisfies the following conditional expressions: 4 mm < f < 5.5 mm; 2.3 mm < EPD < 3.2 mm; 11 mm < TTL < 13 mm; 1.5 < Fno < 2; 16° < CRA < 34°; 0.9 mm < BFL < 4 mm; 60° < FOV < 80°; 5.5 mm < IH < 7.5 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 total 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 target surface, large aperture, and large field of view angle. More specifically, 4.3 mm < f < 5.08 mm; 2.32 mm < EPD < 3.18 mm; 11.49 mm < TTL < 12.81 mm; 1.59 < Fno < 1.91; 16.13° < CRA < 33.17°; 0.97 mm < BFL < 3.94 mm; 61° < FOV < 77°; 5.71 mm < IH < 7.39 mm.

[0066] In some embodiments, the lens material in the optical lens provided by the present invention may 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. In the optical lens provided by the present invention, the first lens is a glass lens, the fourth lens, the fifth lens, and the sixth lens are plastic lenses; the second lens and the third lens are glass or plastic lenses; adopting a glass-plastic hybrid structure can effectively reduce costs, correct aberrations, reduce volume, and provide an optical lens product with higher cost performance.

[0067] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens of the present invention adopts a spherical lens; the fourth lens, the fifth lens, and the sixth lens adopt aspherical lenses; the second lens and the third lens adopt spherical or aspherical lenses.

[0068] In various embodiments of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equation: ; Among them, z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, and F are the conic coefficients of the fourth, sixth, eighth, tenth, and twelfth orders respectively.

[0069] The present invention will be further described below with multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are partially different. For specific differences, 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.

[0070] 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 diaphragm ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a filter G1.

[0071] 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 convex surface; The fourth lens L4 has a positive optical power. Its object side surface S7 is a concave 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 concave surface, and its image side surface S10 is a convex surface; The sixth lens L6 has a positive optical power. Its object side surface S11 is a convex surface, and its image side surface S12 is a convex surface; Both the object side surface S13 and the image side surface S14 of the filter G1 are flat surfaces; The imaging surface S15 is a flat surface.

[0072] The first lens L1 and the third lens L3 adopt glass spherical lenses, and the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 adopt plastic aspherical lenses.

[0073] The relevant parameters of each lens in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0074] Table 1-1 The surface type parameters of the aspherical lens of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0075] Table 1-2 In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 100 are respectively as Figure 2 , Figure 3 shown.

[0076] Figure 2 shows the F-Tan(Theta) distortion curve of Embodiment 1, which represents the distortion of light rays with different wavelengths at different image heights on the imaging surface. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the semi-field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within 0-13%, indicating that the optical lens 100 can well correct the distortion.

[0077] Figure 3 shows the MTF (Modulation Transfer Function) curve graph of Embodiment 1, which represents the modulation degree 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 in this embodiment is above 0.4 within the entire field of view. In the range of 0-120 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] Embodiment 2 Please refer to Figure 4 , 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 difference is that the optical parameters such as the radius of curvature of each lens surface and the lens thickness are different.

[0079] The relevant parameters of each lens in the optical lens 200 in Embodiment 2 are shown in Table 2-1.

[0080] 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.

[0081] Table 2-2 In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 200 are respectively as Figure 5 , Figure 6 shown.

[0082] From Figure 5 it can be seen that the distortion of the optical lens is controlled within 0-13%, indicating that the optical lens 200 can correct the distortion well.

[0083] From Figure 6 it can be seen that the MTF value of this embodiment is above 0.48 within the entire field of view. In the range of 0-120 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0084] Embodiment 3 Please refer to Figure 7 , 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: the object side surface S9 of the fifth lens L5 is a convex surface; the image side surface S10 of the fifth lens L5 is a concave surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

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

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

[0087] Table 3-2 In this embodiment, the F-Tan(Theta) distortion curve graph and MTF curve graph of the optical lens 300 are respectively as shown in Figure 8 , Figure 9 shown.

[0088] From Figure 8 it can be seen that the distortion of the optical lens is controlled within -8% to 0, indicating that the optical lens 300 can correct the distortion well.

[0089] From Figure 9 it can be seen that the MTF value of this embodiment is above 0.5 within the entire field of view. In the range of 0-120 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0090] Embodiment 4 Please refer to Figure 10, which shows a schematic structural diagram of the optical lens 400 provided in Embodiment 4 of the present invention. Compared with Embodiment 1, the main differences are as follows: the image side S6 of the third lens L3 is a concave surface; the object side S9 of the fifth lens L5 is a convex surface; the image side S10 of the fifth lens L5 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0091] The relevant parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0092] Table 4-1 The aspheric lens surface parameters of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0093] Table 4-2 In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 400 are respectively as shown in Figure 11 , Figure 12 shown.

[0094] From Figure 11 it can be seen that the distortion of the optical lens is controlled within -8% to 0, indicating that the optical lens 400 can well correct the distortion.

[0095] From Figure 12 it can be seen that the MTF value of this embodiment is above 0.48 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0096] Embodiment 5 Please refer to Figure 13 , which shows a schematic structural diagram of the optical lens 500 provided in Embodiment 5 of the present invention. Compared with Embodiment 1, the main differences are as follows: the aperture stop ST is arranged between the second lens L2 and the third lens L3; the second lens L2 is a glass spherical lens; the third lens L3 is a plastic aspheric lens; the object side S9 of the fifth lens L5 is a convex surface; the image side S10 of the fifth lens L5 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0097] The relevant parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0098] Table 5-1 The surface parameters of the aspherical lens of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0099] Table 5-2 In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 500 are respectively as shown in Figure 14 、 Figure 15 shown.

[0100] From Figure 14 it can be seen that the distortion of the optical lens is controlled within -8% to 0, indicating that the optical lens 500 can correct distortion well.

[0101] From Figure 15 it can be seen that the MTF value of this embodiment is above 0.38 within the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve smoothly decreases uniformly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0102] Embodiment 6 Please refer to Figure 16 , which shows the structural schematic diagram of the optical lens 600 provided in Embodiment 6 of the present invention. Compared with Embodiment 1, the main differences are: the aperture stop ST is disposed between the second lens L2 and the third lens L3; the image side surface S10 of the fifth lens L5 is a concave surface; the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0103] The relevant parameters of each lens in the optical lens 600 in Embodiment 6 are shown in Table 6-1.

[0104] Table 6-1 The surface parameters of the aspherical lens of the optical lens 600 in Embodiment 6 are shown in Table 6-2.

[0105] Table 6-2 In this embodiment, the F-Tan(Theta) distortion curve graph and the MTF curve graph of the optical lens 600 are respectively as shown in Figure 17 、 Figure 18 shown.

[0106] From Figure 17 it can be seen that the distortion of the optical lens is controlled within -21% to 0, indicating that the optical lens 600 can correct distortion well.

[0107] From Figure 18It can be seen that the MTF value of this embodiment is above 0.38 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases uniformly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency cases.

[0108] Please refer to Table 7 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 chief ray angle of incidence CRA at the maximum image height, the maximum field of view angle FOV, and the values corresponding to each conditional expression in each embodiment.

[0109] Table 7 In summary of the above embodiments, the optical lens provided by the present invention uses six 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 aberrations, and improve the imaging quality of the optical lens, making the lens have one or more advantages such as miniaturization, large target surface, large aperture, large field of view angle, and high imaging quality.

[0110] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", 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 any one or more embodiments or examples in a suitable manner.

[0111] The above embodiments only 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 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 patent of the present invention should be subject to the appended claims.

Claims

1. An optical lens, consisting of six lenses in total, characterized in that, Along the optical axis from the object side to the imaging surface, it includes: The first lens has a negative optical power, and its object side surface is concave and its image side surface is concave; The second lens has positive refractive power, its object side surface is convex, and its image side surface is concave; The third lens has positive power and its object side surface is convex; a fourth lens having positive refractive power, whose object-side surface is concave and whose image-side surface is convex; a fifth lens having negative optical power; a sixth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is convex; The object side curvature radius R7 of the fourth lens and the image side curvature radius R8 of the fourth lens satisfy: -0.1<(R7-R8) / (R7+R8)<1; A curvature radius R1 of the object side surface of the first lens and a curvature radius R2 of the image side surface of the first lens satisfy: -0.6<(R1+R2) / (R1-R2)<0.

9.

2. The optical lens according to claim 1, wherein The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 <TTL / f<2.7;所述光学镜头的光学总长TTL与所述光学镜头的最大视场角所对应的真实像高IH满足:1.5<TTL / IH<2.3。 3. The optical lens according to claim 1, wherein The real image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.7 <IH / EPD<3.2;所述光学镜头的最大视场角所对应的真实像高IH与所述光学镜头的有效焦距f满足:1.1<IH / f<1.8。 4. The optical lens according to claim 1, wherein The semi-aperture d1 of the object side of the first lens, the real 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: 0.77 <d1 / (IH / 2) / tan(FOV / 2)<1.81;所述光学镜头还包括一光阑,所述光阑位于所述第三透镜与所述第四透镜之间或所述第二透镜与所述第三透镜之间,位于所述光阑后的各透镜的组合焦距f后与所述光学镜头的有效焦距f满足:0.7<f后 / f<2。 5. The optical lens according to claim 1, wherein The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.4 <f1 / f<-0.8;所述第一透镜的物侧面曲率半径R1与所述光学镜头的有效焦距f满足:-9<R1 / f<-1.1;所述第一透镜的像侧面曲率半径R2与所述光学镜头的有效焦距f满足:0.6<R2 / f<5.9。 6. The optical lens according to claim 1, wherein The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.8 <f2 / f<11;所述第二透镜的物侧面曲率半径R3与所述光学镜头的有效焦距f满足:1.2<R3 / f<2.5;所述第二透镜的像侧面曲率半径R4与所述光学镜头的有效焦距f满足:2.1<R4 / f<10。 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: 0.7 < f3 / f < 2.2; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.4 < f5 / f < -0.

6.

8. The optical lens according to claim 1, wherein The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.8 < f4 / f < 25; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -1; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -0.

4.

9. The optical lens according to claim 1, wherein The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.6 < f6 / f < 10; the object-side curvature radius R11 of the sixth lens and the effective focal length f of the optical lens satisfy: 0.5 < R11 / f < 12.4; the image-side curvature radius R12 of the sixth lens and the effective focal length f of the optical lens satisfy: -10.5 < R12 / f < -0.

6.

10. The optical lens according to claim 1, characterized in that, The object-side curvature radius R3 of the second lens and the image-side curvature radius R4 of the second lens satisfy: -0.8 < (R3 - R4) / (R3 + R4) < -0.1; the object-side curvature radius R11 of the sixth lens and the image-side curvature radius R12 of the sixth lens satisfy: -0.2 < (R11 + R12) / (R11 - R12) < 0.8.

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