Optical lens

Abstract

The application discloses an optical lens, which comprises six lenses in sequence along an optical axis from an object side to an imaging surface, wherein the six lenses comprise a first lens with negative optical power, an object side surface of the first lens being a concave surface; a second lens with positive optical power, an object side surface of the second lens being a convex surface and an image side surface being a convex surface; a third lens with positive optical power, an image side surface of the third lens being a convex surface; a fourth lens with positive optical power, an object side surface of the fourth lens being a concave surface and an image side surface being a convex surface; a fifth lens with negative optical power, an object side surface of the fifth lens being a concave surface and an image side surface being a concave surface; and a sixth lens with positive optical power, an object side surface of the sixth lens being a convex surface and an image side surface being a concave surface. The optical lens has the advantages of long focal length, miniaturization, low cost, high resolution, normal use in weak light and harsh environment, and at least one of the advantages.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of imaging lenses, in particular to an optical lens. BACKGROUND

[0002] With the increasing demand for driving experience, vehicle application type optical lenses are increasingly used in intelligent driving, and vehicle optical lenses are playing an increasingly important role in the automotive industry.

[0003] In vehicle cameras, front-view cameras are the core components of ADAS (Advanced Driver Assistance System), mainly responsible for forward collision warning, lane deviation warning, and pedestrian detection functions. Currently, front-view cameras are usually much more expensive than other types of cameras due to the complex algorithms and chip processing involved, which also reflects the important role of front-view cameras in vehicle camera systems. With the rapid development of advanced driver assistance systems, the requirements for front-view lenses are also increasing. Therefore, it is necessary to develop an optical lens with good imaging effect. SUMMARY

[0004] Therefore, the purpose of the present application is to provide an optical lens with at least one of the advantages of long focal length, miniaturization, low cost, high resolution, and normal use in weak light and harsh environments.

[0005] The present application provides an optical lens, which includes six lenses in order along the optical axis from the object side to the imaging surface: a first lens with negative focal power, the object side surface of which is concave; a second lens with positive focal power, the object side surface of which is convex and the image side surface of which is convex; a third lens with positive focal power, the image side surface of which is convex; a fourth lens with positive focal power, the object side surface of which is concave and the image side surface of which is convex; a fifth lens with negative focal power, the object side surface of which is concave and the image side surface of which is concave; and a sixth lens with positive focal power, the object side surface of which is convex and the image side surface of which is concave.

[0006] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface satisfy: (R3-R4) / (R3+R4) <-1.2.

[0007] In some embodiments, the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface satisfy: 0.45<(R7-R8) / (R7+R8)<0.85.

[0008] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.7<TTL / f<2.3.

[0009] In some embodiments, the optical lens satisfies: 0.95 < (IH / 2) / (f x Tan(FOV / 2)) < 1.05, where IH is the image height corresponding to the maximum field angle of the optical lens, f is the effective focal length of the optical lens, and FOV is the maximum field angle of the optical lens.

[0010] In some embodiments, the optical lens satisfies: 55 < 180° x TTL / (IH / 2) / (FOV / 2) < 75, where TTL is the total track length of the optical lens, IH is the image height corresponding to the maximum field angle of the optical lens, and FOV is the maximum field angle of the optical lens.

[0011] In some embodiments, the effective focal length f2 of the second lens satisfies: 1.3 < f2 / f < 3, where f is the effective focal length of the optical lens.

[0012] In some embodiments, the effective focal length f4 of the fourth lens satisfies: 1.3 < f4 / f < 2, where f is the effective focal length of the optical lens.

[0013] In some embodiments, the radius of curvature R1 of the object side surface of the first lens satisfies: R1 / f < -0.5, where f is the effective focal length of the optical lens.

[0014] In some embodiments, the radius of curvature R10 of the image side surface of the fifth lens satisfies: 1.3 < R10 / f < 2.7, where f is the effective focal length of the optical lens.

[0015] Compared with the prior art, the optical lens provided by the present application adopts six lenses with optical power, and has at least one of the advantages of long focal length, miniaturization, low cost, high resolution, normal use in weak light and harsh environment, etc. by specific surface shape setting and reasonable power distribution. In particular, the object side surface of the first lens is concave, which plays a role in diverging light rays, and the light rays passing through the object side surface of the first lens can make the subsequent lenses have a larger light acceptance surface. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the description of the embodiments, taken in conjunction with the following drawings in which:

[0017] Figure 1 FIG. 1 is a structural diagram of an optical lens according to an embodiment of the present application.

[0018] Figure 2 FIG. 2 is a field curvature curve of the optical lens according to the embodiment of the present application.

[0019] Figure 3 FIG. 3 is an F-Tan(Theta) distortion curve of the optical lens according to the embodiment of the present application.

[0020] Figure 4A MTF curve diagram of the optical lens in Embodiment 1 of the present application.

[0021] Figure 5 A structure diagram of the optical lens in Embodiment 2 of the present application.

[0022] Figure 6 A field curvature curve diagram of the optical lens in Embodiment 2 of the present application.

[0023] Figure 7 An F-Tan(Theta) distortion curve diagram of the optical lens in Embodiment 2 of the present application.

[0024] Figure 8 A MTF curve diagram of the optical lens in Embodiment 2 of the present application.

[0025] Figure 9 A structure diagram of the optical lens in Embodiment 3 of the present application.

[0026] Figure 10 A field curvature curve diagram of the optical lens in Embodiment 3 of the present application.

[0027] Figure 11 An F-Tan(Theta) distortion curve diagram of the optical lens in Embodiment 3 of the present application.

[0028] Figure 12 A MTF curve diagram of the optical lens in Embodiment 3 of the present application. DETAILED DESCRIPTION

[0029] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of embodiments of the present application and is not intended to limit the scope of the present application in any way. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0030] It is noted that, in this specification, the expressions first, second, third, etc. are merely used to distinguish one feature from another, and do not indicate any limitation on the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0031] In the drawings, the thickness, size, and shape of lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of a spherical surface or an aspherical surface shown in the drawings is shown by way of example. That is, the shape of a spherical surface or an aspherical surface is not limited to the shape of a spherical surface or an aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0032] In the present disclosure, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not specified, 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 specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the imaging plane is referred to as the image side surface of the lens.

[0033] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when expressions such as "at least one of" appear after a list of items, it modifies the entire list of items and not the individual items themselves. Furthermore, when describing embodiments of the present application, the word "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0034] Unless otherwise defined, all terms (including technical and scientific terms) used herein 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 the terms should be interpreted as having a meaning that is 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.

[0035] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0036] The present application provides an optical lens, which comprises six lenses in sequence from an object side to an imaging plane along an optical axis, i.e., a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, and the optical centers of the lenses are located on the same line.

[0037] In some embodiments, the first lens is configured to have a negative focal power, which is beneficial for diverging light rays. Under the same field of view angle condition, the light rays emitted from the image side surface of the first lens can provide a larger light acceptance for the subsequent optical system, thereby reducing the front aperture. The object side surface is concave, which is beneficial for diverging light rays. The light rays emitted from the object side surface of the first lens can provide a larger light acceptance for the subsequent lens.

[0038] In some embodiments, the second lens is configured to have positive refractive power, which is conducive to converging light rays, and is matched with the first lens having negative refractive power, so as to reduce the total length of the optical lens and further reduce the rear aperture; the object side is convex, and the image side is convex, which can converge the light rays passing through the first lens and reduce the height of the light rays, so as to reduce the aperture of the object side of the fourth lens while slowing down the turning trend of the light rays and making the transition smooth, and meanwhile, the various aberrations generated by the front lens can be balanced, thereby improving the overall imaging quality of the optical lens.

[0039] In some embodiments, the third lens is configured to have positive refractive power, which is conducive to receiving the light rays converged by the second lens, reducing the height of the light beam when incident on the object side of the fourth lens, and reducing the aperture of the object side of the fourth lens; the image side is convex, which can smoothly receive the light rays, so that the light rays emitted by the second lens can smoothly enter the rear optical system, reduce the generation of aberrations, and improve the imaging quality. The edge field of view light rays can be deflected towards the optical axis after passing through the second side of the third lens, which is conducive to reducing the rear aperture of the system.

[0040] In some embodiments, the fourth lens is configured to have positive refractive power, which is conducive to converging light rays, and is matched with the fifth lens, so as to effectively correct the aberrations of the optical lens, improve the imaging quality, and optimize the optical performance such as distortion; the object side is concave, and the image side is convex, which can suppress the angle of the edge field of view incident on the imaging surface, effectively transfer more light beams to the imaging surface, and improve the imaging quality.

[0041] In some embodiments, the fifth lens is configured to have negative refractive power, which is conducive to diverging light rays, so that the subsequent optical system has a larger light beam receiving surface, improves the optical performance, effectively corrects various aberrations brought by the front lens, and improves the imaging quality of the optical lens; the object side is concave, and the image side is concave, which can adjust the light rays of the central field of view and the edge field of view passing through the fifth lens, especially adjust the angle of the edge field of view light rays incident on the imaging surface so that the chief ray is parallel to the imaging surface, thereby improving the proportion of the edge field of view in the imaging picture, enhancing the imaging clarity of the edge field of view, and correcting various aberrations brought by the front lens, thereby improving the overall imaging quality of the optical lens.

[0042] In some embodiments, the sixth lens is configured to have positive refractive power, which is conducive to receiving the front light rays and improving the resolution, and further, the fifth lens receives the compressed light rays of the front positive lens, reduces the angle of the light rays, and meets the requirement of CRA; the object side is convex, and the image side is concave, which can optimize the spherical aberration, improve the imaging quality, effectively suppress the angle of the edge field of view incident on the imaging surface, and effectively transfer more light beams to the imaging surface, thereby improving the imaging quality.

[0043] In some embodiments, a diaphragm can be arranged between the first lens and the second lens. It can be understood that the diaphragm can be used to limit the amount of light to change the brightness of the image. In addition, when the diaphragm is located between the first lens and the second lens, the diaphragm can reasonably distribute the functions of the first lens to the sixth lens, for example, the first lens can be used to receive light to a greater extent, and the second lens to the sixth lens can be used to correct the function of aberration, which is conducive to balancing the structure of the entire optical system. In addition, when the diaphragm is located between the first lens and the second lens, it is convenient to correct the diaphragm aberration and balance the structure and focal length distribution of the front lens group and the rear lens group.

[0044] In some embodiments, the optical lens can further include a filter arranged between the sixth lens and the imaging surface, used to filter out interference light to prevent interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0045] In some embodiments, the effective focal length f of the optical lens satisfies: 13mm < f < 17mm. Satisfying the above range is conducive to making the optical lens have a long focal length characteristic, which can ensure the telephoto effect of the optical lens and make the system have a larger magnification, and has a better imaging quality for the scene in a larger distance.

[0046] In some embodiments, the maximum field angle FOV of the optical lens satisfies: 30° < FOV < 40°. Satisfying the above range is conducive to making the optical lens have a suitable field angle, which can clearly capture a target at a distance.

[0047] In some embodiments, the aperture value FNO of the optical lens satisfies: 1.4 < FNO < 1.8. Satisfying the above range is conducive to realizing a large aperture characteristic, which can also ensure the clarity of the image in a weak light environment or at night.

[0048] In some embodiments, the maximum field angle chief ray angle CRA of the optical lens satisfies: 16° < CRA < 21°. Satisfying the above range can make the CRA of the optical lens have a larger allowable error range with the CRA of the chip light sensing element, which improves the adaptation ability of the optical lens to the image sensor.

[0049] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.7 < TTL / f < 2.3. Satisfying the above range can effectively compress the total length, ensure sufficient space to adjust the lens structure, and optimize the imaging effect of the optical lens.

[0050] In some embodiments, the image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy: 0.95 < (IH / 2) / (f x Tan(FOV / 2)) < 1.05. Satisfying the above range can better control the distortion of the optical lens, have the characteristic of small distortion, and improve the resolution of the optical lens.

[0051] In some embodiments, the 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: 0.6 < IH / f < 0.7. Satisfying the above range can ensure that the chip matches a large image surface, so that the optical lens has the characteristics of long focal length and large image surface.

[0052] In some embodiments, the optical back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.3 < BFL / f < 0.5. Satisfying the above range can balance the optical back focal length between good imaging quality and ease of assembly, which is conducive to ensuring the imaging quality of the optical lens while avoiding interference between the lens and other elements, reducing the assembly process difficulty of the camera module, and improving the production yield.

[0053] In some embodiments, the total optical length TTL of the optical lens, the 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: 55 < 180° x TTL / (IH / 2) / (FOV / 2) < 75. Satisfying the above range can limit the length of the optical lens under the condition of the same imaging area and the same field of view, and realize the miniaturization of the optical lens.

[0054] 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: 0.5 < ∑CT / TTL < 0.7. Satisfying the above range can compress the total length of the optical lens, so that the structure of the optical lens is more compact.

[0055] In some embodiments, the half light passing diameter d1 of the object side surface of the first lens, the 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: 3.3 < d1 / (IH / 2) / Tan(FOV / 2) < 4. Satisfying the above range can make the front aperture small under the condition that the optical lens has a suitable field of view and image height, which is conducive to the miniaturization of the optical lens.

[0056] In some embodiments, the effective focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: f1 / f <-2.2. Satisfying the above range, a large range of light rays can enter the optical lens, more image information can be obtained, and the lens distortion and the field curvature can be controlled, and the geometric accuracy of the imaging surface can be improved. Preferably, -4.5

[0057] In some embodiments, the effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.3

[0058] In some embodiments, the effective focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: 1

[0059] In some embodiments, the effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.3

[0060] In some embodiments, the effective focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: -1.7

[0061] In some embodiments, the effective focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: 2.5

[0062] In some embodiments, the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: R1 / f <-0.5. Satisfying the above range, the concave surface can be towards the object side, and the light rays passing through the object side of the first lens can have a larger light acceptance surface for the subsequent lenses. Preferably, -3.8

[0063] In some embodiments, the radius of curvature R6 of the image side surface of the third lens and the effective focal length f of the optical lens satisfy: -0.7 < R6 / f < -0.4. Satisfying the above range can make the convex surface face the image side, converge the edge field of view light, and improve the edge field of view imaging quality.

[0064] In some embodiments, the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1.3 < R10 / f < 2.7. Satisfying the above range can make the concave surface face the image side, and cooperate with the fourth lens to reduce chromatic aberration and improve imaging quality.

[0065] In some embodiments, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the image side surface satisfy: (R3-R4) / (R3+R4) < -1.2. Satisfying the above range is conducive to smooth transition of light to the rear, collecting more light into the lens, achieving small aperture and short total length while improving resolution.

[0066] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface satisfy: 0.45 < (R7-R8) / (R7+R8) < 0.85. Satisfying the above range helps to control the edge field of view light beam trend to increase the image height, while reducing the off-axis aberration of the optical lens.

[0067] In some embodiments, the radius of curvature R9 of the object side surface of the fifth lens and the radius of curvature R10 of the image side surface satisfy: 7 < |(R9-R10) / (R9+R10)|. Satisfying the above range is conducive to reducing the field curvature, and reducing the difficulty of field curvature correction of subsequent lenses, and improving imaging quality. Preferably, 7 < |(R9-R10) / (R9+R10)| < 11.

[0068] In some embodiments, the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface satisfy: 0.05 < (R11-R12) / (R11+R12) < 0.15. Satisfying the above range helps to control the edge field of view light beam trend to increase the image height, while reducing the off-axis aberration of the optical lens.

[0069] In some embodiments, the radius of curvature 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 < 2.1. Satisfying the above range can make the convex surface face the object side, so that the light emitted by the first lens can smoothly enter the fourth lens, and more light can be collected to improve the imaging surface detail quality, reduce the generation of aberration, and improve the imaging quality.

[0070] In some embodiments, the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: -2 < R4 / f. Satisfying the above range can make the convex surface face the image side, converge light rays, improve the central field of view imaging quality, increase the depth of field, and improve the imaging quality. Preferably, -14.8 < R4 / f < -2.

[0071] In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: R7 / f < -2. Satisfying the above range can make the concave surface face the object side, improve the detail quality of the edge field of view of the imaging surface, reduce the generation of aberration, and improve the imaging quality.

[0072] In some embodiments, the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -0.9 < R8 / f < -0.7. Satisfying the above range can make the convex surface face the image side, further converge light rays, suppress the angle of the edge field of view incident on the imaging surface, effectively transfer more light beams to the imaging surface, and improve the imaging quality.

[0073] As an embodiment, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens can be all-glass lenses or glass-plastic hybrid lenses, both of which can achieve good imaging effects. In this application, in order to improve the imaging quality of the lens, each lens is a glass lens. At the same time, at least one of the object side surface or the image side surface of the second lens and the sixth lens is an aspherical surface. The aspherical lens has the following characteristics: from the center of the lens to the periphery of the lens, the curvature is continuously changed, which is different from the spherical lens with constant curvature from the center of the lens to the periphery of the lens. The aspherical lens has better curvature radius characteristics and has the advantages of improving the distortion aberration and improving the astigmatism aberration.

[0074] In order to make the system have better optical performance, multiple aspherical lenses are used in the lens, and the shape of each aspherical surface of the optical lens satisfies the following equation:

[0075]

[0076] wherein z is the distance of the curved surface to the vertex of the curved surface in the direction of the optical axis, h is the distance of the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, A, B, C, D, E, and F are the second-order, fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients, respectively.

[0077] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, the material selection of each lens in the optical lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, any changes, substitutions, combinations or simplifications made without departing from the innovative points of the application should be regarded as equivalent replacement, and are included in the protection scope of the application.

[0078] Embodiment 1

[0079] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens provided in the embodiment 1 of the application. The optical lens includes, along the optical axis from the object side to the imaging surface S15, a first lens L1, a diaphragm ST, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a filter G1.

[0080] The first lens L1 is a spherical lens with negative focal power, the object side surface S1 of the first lens is a concave surface, and the image side surface S2 of the first lens is a convex surface; the second lens L2 is an aspherical lens with positive focal power, the object side surface S3 of the second lens is a convex surface, and the image side surface S4 of the second lens is a convex surface; the third lens L3 is a spherical lens with positive focal power, the object side surface S5 of the third lens is a concave surface, and the image side surface S6 of the third lens is a convex surface; the fourth lens L4 is a spherical lens with positive focal power, the object side surface S7 of the fourth lens is a concave surface, and the image side surface S8 of the fourth lens is a convex surface; the fifth lens L5 is a spherical lens with negative focal power, the object side surface S9 of the fifth lens is a concave surface, and the image side surface S10 of the fifth lens is a concave surface; the sixth lens L6 is an aspherical lens with positive focal power, the object side surface S11 of the sixth lens is a convex surface, and the image side surface S12 of the sixth lens is a concave surface; the object side surface S13 and the image side surface S14 of the filter G1 are both flat surfaces.

[0081] Specifically, the design parameters of each lens of the optical lens provided in the embodiment are shown in Table 1-1.

[0082] Table 1-1

[0083]

[0084] The surface type coefficients of each aspherical surface of the optical lens in the embodiment are shown in Table 1-2.

[0085] Table 1-2

[0086] Face number K A B C S3 -5.90E-01 0.00E+00 0.00E+00 -3.24E-05 S4 -5.08E+01 0.00E+00 0.00E+00 -7.67E-06 S11 -6.58E-01 0.00E+00 -9.41E-05 -2.07E-08 S12 -4.11E-01 0.00E+00 3.03E-05 1.22E-05 Face number D E F S3 2.18E-06 -7.17E-08 7.23E-10 S4 1.09E-06 -4.00E-08 4.21E-10 S11 -2.33E-08 6.14E-10 -1.66E-11 S12 -1.46E-06 6.79E-08 -1.30E-09

[0087] Figure 2The field curvature curve of the embodiment 1 is shown, which represents the bending degree of the meridional image surface and the sagittal image surface of the light rays of different wavelengths, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image surface and the sagittal image surface is controlled within 0.05-0.2 mm, which shows that the optical lens can well correct the field curvature.

[0088] Figure 3 The distortion curve of the embodiment 1 is shown, which represents the F-Tan (Theta) distortion of different field angles on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the distortion value is controlled within the range of-1.2% to 0, which shows that the optical lens has small distortion, the image compression in the edge angle region is relatively flat, and the clarity of the unfolded image is effectively improved.

[0089] Figure 4 The modulation transfer function (MTF) curve of the embodiment 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.2 within the full field of view, and the MTF curve uniformly and smoothly decreases from the center to the edge field of view within the range of 0-120 lp / mm, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0090] Embodiment 2

[0091] Please refer to Figure 5 , which is a structural schematic diagram of the optical lens provided by the embodiment 2 of the present application. The optical lens of the embodiment is substantially the same as the embodiment 1 described above, and the difference lies in that the curvature radius of each lens surface, the thickness of each lens, and the aspheric surface coefficient and other parameters are different.

[0092] Specifically, the design parameters of each lens of the optical lens provided by the embodiment are shown in Table 2-1.

[0093] Table 2-1

[0094]

[0095]

[0096] The aspheric surface coefficients of the optical lens in the embodiment are shown in Table 2-2.

[0097] Table 2-2

[0098] Face number K A B C S3 -8.88E+00 0.00E+00 0.00E+00 -3.30E-05 S4 -5.03E+01 0.00E+00 0.00E+00 -9.16E-06 S11 -6.33E-01 0.00E+00 -6.97E-05 3.93E-08 S12 -4.41E-01 0.00E+00 9.26E-05 6.00E-06 Face number D E F S3 2.06E-06 -7.27E-08 7.66E-10 S4 9.86E-07 -3.79E-08 4.34E-10 S11 -3.27E-08 1.91E-11 -9.77E-12 S12 -5.14E-07 1.78E-08 -4.55E-10

[0099] Figures 6 to 8The field curvature curve, the distortion curve and the modulation transfer function (MTF) curve of the optical lens of the embodiment 2 are shown respectively. As can be seen from the figures, the field curvature of the meridional image surface and the sagittal image surface is controlled within 0-0.15 mm, which shows that the optical lens can correct the field curvature well; the distortion value is controlled within the range of 0.8%-0, which shows that the optical lens has small distortion; the MTF value of the optical lens is above 0.25 within the full field of view, and within the range of 0-120 lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and the optical lens has good imaging quality and good detail resolution ability in the low frequency and high frequency conditions.

[0100] Embodiment 3

[0101] Please refer to Figure 9 , which is a structural schematic view of the optical lens provided by the embodiment 3 of the present application. The optical lens of the embodiment is substantially the same as the optical lens of the above-mentioned embodiment 1, and the difference lies in that the curvature radius of each lens surface, the thickness of each lens, the aspheric surface coefficient and other parameters are different.

[0102] Specifically, the design parameters of each lens of the optical lens provided by the embodiment are shown in Table 3-1.

[0103] Table 3-1

[0104]

[0105]

[0106] The aspheric surface coefficients of each lens of the optical lens in the embodiment are shown in Table 3-2.

[0107] Table 3-2

[0108] Face number K A B C S3 -5.46E+01 0.00E+00 0.00E+00 -3.53E-05 S4 -4.65E+01 0.00E+00 0.00E+00 -8.93E-06 S11 -6.34E-01 0.00E+00 -1.17E-04 -1.24E-06 S12 -5.46E-01 0.00E+00 1.84E-04 -4.29E-06 Face number D E F S3 2.17E-06 -7.09E-08 7.63E-10 S4 1.02E-06 -3.26E-08 3.48E-10 S11 -3.10E-07 3.29E-09 -4.32E-11 S12 -1.42E-06 3.22E-08 -3.52E-10

[0109] Figures 10 to 12 The field curvature curve, the distortion curve and the modulation transfer function (MTF) curve of the optical lens of the embodiment 3 are shown respectively. As can be seen from the figures, the field curvature of the meridional image surface and the sagittal image surface is controlled within-0.05 mm-0.2 mm, which shows that the optical lens can correct the field curvature well; the distortion value is controlled within the range of 0-1.2%, which shows that the optical lens has small distortion; the MTF value of the optical lens is above 0.2 within the full field of view, and within the range of 0-120 lp / mm, the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view, and the optical lens has good imaging quality and good detail resolution ability in the low frequency and high frequency conditions.

[0110] Please refer to Table 4, which shows the optical characteristics of the optical lens provided in the above three embodiments, including effective focal length f, maximum field of view FOV, pupil diameter EPD, total optical length TTL, aperture value FNO, image height IH corresponding to the maximum field of view, chief ray angle CRA, optical back focal length BFL, and the numerical value corresponding to each conditional expression in each embodiment.

[0111] Table 4

[0112]

[0113]

[0114] In summary, the optical lens in the embodiments of the present application adopts six lenses with optical power, and by reasonably allocating the optical power of each lens, reasonably matching the surface shape of each lens, reasonably setting the thickness of each lens and the distance between lenses, reasonably setting the position of the aperture, and setting the optical lens to have small distortion, the balance of long focal length (the maximum value of f is 15.20mm), large aperture (the minimum value of FNO is 1.60) and high pixels can be achieved, thereby meeting the use requirements of vehicle-mounted lenses.

[0115] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a 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 application. In the present specification, the illustrative description of the above terms does 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.

[0116] The above-described embodiments only express several implementation manners of the present application, which are described in a more specific and detailed manner, but should not be understood as a limitation on the scope of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. An optical lens comprising six lenses, characterized in that, Along the optical axis from the object side to the imaging plane, the following are included in sequence: The first lens with negative optical power has a concave object side. A second lens with positive optical power has a convex object-side surface and a convex image-side surface; A third lens with positive optical power has a convex image-side surface; The fourth lens with positive optical power has a concave object side and a convex image side. The fifth lens with negative optical power has a concave object side and a concave image side. The sixth lens with positive optical power has a convex object side and a concave image side. The radius of curvature R7 of the object side and the radius of curvature R8 of the image side of the fourth lens satisfy: 0.45 < (R7-R8) / (R7+R8) < 0.85; The total optical length TTL of the optical lens, the 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: 55 < 180° × TTL / (IH / 2) / (FOV / 2) < 75.

2. The optical lens according to claim 1, characterized in that, The radius of curvature R3 of the object side and the radius of curvature R4 of the image side of the second lens satisfy: -6.15≤(R3-R4) / (R3+R4)<-1.

2.

3. The optical lens according to claim 1, characterized in that, The radius of curvature R7 of the object side and the radius of curvature R8 of the image side of the fourth lens satisfy: 0.50≤(R7-R8) / (R7+R8)≤0.

78.

4. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy the following condition: 1.7 < TTL / f < 2.

3.

5. The optical lens according to claim 1, characterized in that, The image height IH corresponding to the maximum field of view of the optical lens, the effective focal length f of the optical lens, and the maximum field of view FOV of the optical lens satisfy the following: 0.95<(IH / 2) / (f×Tan(FOV / 2))<1.

05.

6. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens, the 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: 61.69≤180°×TTL / (IH / 2) / (FOV / 2)≤70.

17.

7. The optical lens according to claim 1, characterized in that, The effective focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 1.3 < f2 / f < 3.

8. The optical lens according to claim 1, characterized in that, The effective focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy the following condition: 1.3 < f4 / f < 2.

9. The optical lens according to claim 1, characterized in that, The radius of curvature R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -3.8 < R1 / f < -0.

5.

10. The optical lens according to claim 1, characterized in that, The radius of curvature R10 of the image side of the fifth lens and the effective focal length f of the optical lens satisfy the following condition: 1.3 < R10 / f < 2.7.

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