Optical lens

Abstract

The application provides an optical lens, which comprises six lenses in sequence along an optical axis from an object side to an imaging surface, and the six lenses comprise: a first lens with negative focal power, wherein the object side surface is a concave surface, and the image side surface is a concave surface; a second lens with positive focal power, wherein the object side surface is a convex surface, and the image side surface is a concave surface; a third lens with positive focal power, wherein the object side surface is a convex surface, and the image side surface is a convex surface; a fourth lens with positive focal power, wherein the object side surface is a concave surface, and the image side surface is a convex surface; a fifth lens with negative focal power, wherein the object side surface is a concave surface, and the image side surface is a convex surface; and a sixth lens with positive focal power, wherein the object side surface is a convex surface. The optical lens provided by the application can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and make the lens have one or more advantages such as miniaturization, a large target surface, a large aperture, a large field of view, high imaging quality and the like.

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 continuous improvement of people's requirements for driving experience, vehicle-mounted application type optical lenses are used more and more in intelligent driving, and vehicle-mounted optical lenses are continuously improving in the automobile industry.

[0003] Electronic rearview mirror is an indirect vision device that acquires a specified field of view through a camera and a monitor system. It contains high-definition cameras, digital vision processing systems, safety systems, liquid crystal displays, and other electronic devices, and is a new type of rearview mirror that can replace traditional rearview mirrors. Electronic rearview mirrors are generally designed with a main lens and a wide-angle lens, which present images through a display screen, providing a wider field of view, eliminating blind spots, and helping drivers better understand the surrounding environment and reducing accidents. The lenses of existing electronic rearview mirrors require not only a light, thin, and small shape and high pixel and high resolution, but also clear imaging under low illumination conditions, so an optical lens with good imaging effect needs to be developed. SUMMARY

[0004] To solve the above problems, the present application aims to provide an optical lens with excellent imaging quality.

[0005] The technical scheme adopted by the present application is as follows:

[0006] An optical lens, comprising six lenses, arranged in order along the optical axis from the object side to the imaging surface, comprising:

[0007] a first lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave;

[0008] a second lens with positive focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0009] a third lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0010] a fourth lens with positive focal power, the object side surface of which is concave, and the image side surface of which is convex;

[0011] a fifth lens with negative focal power, the object side surface of which is concave, and the image side surface of which is convex;

[0012] a sixth lens with positive focal power, the object side surface of which is convex;

[0013] The object side surface radius of curvature R3 of the second lens and the image side surface radius of curvature R4 of the second lens satisfy: -0.9 < (R3-R4) / (R3+R4) < -0.1.

[0014] The object side surface radius of curvature R9 of the fifth lens and the image side surface radius of curvature R10 of the fifth lens satisfy: -1 < (R9-R10) / (R9+R10) < -0.2.

[0015] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3 < TTL / f < 3.1; the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 1.5 < TTL / IH < 2.4.

[0016] Further preferably, the real 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 real 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 < IH / f < 1.8.

[0017] Further preferably, the object side surface half aperture radius d1 of the first lens, the real 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) < 1.67; the optical lens further comprises a diaphragm, the diaphragm is located between the third lens and the fourth lens or between the second lens and the third lens, the combined focal length f of the lenses before the diaphragm and the combined focal length f of the lenses after the diaphragm satisfy: 0 < fbefore / fafter < 4.2.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -0.9; the object side surface radius of curvature R1 of the first lens and the effective focal length f of the optical lens satisfy: -3.5 < R1 / f < -1.1; the image side surface radius of curvature R2 of the first lens and the effective focal length f of the optical lens satisfy: 1.1 < R2 / f < 3.4.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.3 < f2 / f < 25; the object side surface radius of curvature R3 of the second lens and the effective focal length f of the optical lens satisfy: 0.7 < R3 / f < 5; the image side surface radius of curvature R4 of the second lens and the effective focal length f of the optical lens satisfy: 2.7 < R4 / f < 11.

[0020] It is further preferred that the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 0.7 < f3 / f < 1; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: 0.6 < f6 / f < 25.

[0021] It is further preferred that the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 3 < f4 / f < 35; the object side surface curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -3.2; the image side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -3.4 < R8 / f < -1.3.

[0022] It is further preferred that the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.7 < f5 / f < -0.6; the object side surface curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.65 < R9 / f < -0.1; the image side surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -12 < R10 / f < -0.3.

[0023] It is further preferred that the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0 < (R7-R8) / (R7+R8) < 0.8; the object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: -0.1 < (R1+R2) / (R1-R2) < 0.4.

[0024] The optical lens provided by the application adopts six lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of miniaturization, large target surface, large aperture, large field of view, high imaging quality, etc. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0026] Figure 1 FIG. 1 is a structural schematic diagram of an optical lens according to an embodiment of the present application.

[0027] Figure 2 FIG. 2 is an F-Tan(Theta) distortion curve diagram of the optical lens according to the embodiment 1 of the present application.

[0028] Figure 3 FIG. 3 is an MTF curve diagram of the optical lens according to the embodiment 1 of the present application.

[0029] Figure 4 Structure diagram of the optical lens in Embodiment 2 of the present application.

[0030] Figure 5 F-Tan(Theta) distortion curve diagram of the optical lens in Embodiment 2 of the present application.

[0031] Figure 6 MTF curve diagram of the optical lens in Embodiment 2 of the present application.

[0032] Figure 7 Structure diagram of the optical lens in Embodiment 3 of the present application.

[0033] Figure 8 F-Tan(Theta) distortion curve diagram of the optical lens in Embodiment 3 of the present application.

[0034] Figure 9 MTF curve diagram of the optical lens in Embodiment 3 of the present application.

[0035] Figure 10 Structure diagram of the optical lens in Embodiment 4 of the present application.

[0036] Figure 11 F-Tan(Theta) distortion curve diagram of the optical lens in Embodiment 4 of the present application.

[0037] Figure 12 MTF curve diagram of the optical lens in Embodiment 4 of the present application.

[0038] Figure 13 Structure diagram of the optical lens in Embodiment 5 of the present application.

[0039] Figure 14 F-Tan(Theta) distortion curve diagram of the optical lens in Embodiment 5 of the present application.

[0040] Figure 15 MTF curve diagram of the optical lens in Embodiment 5 of the present application.

[0041] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0042] For a better understanding of the present application, various aspects of the present application will be described in more detail 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 in any way to limit the scope of the present application. Throughout the description, 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.

[0043] It should be noted that the terms first, second, third, etc. in the present specification are only used to distinguish one feature from another, and do not represent any limitation on the features. Therefore, 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.

[0044] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shape of the spherical surface or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or aspherical surface is not limited to the shape of the spherical surface or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0045] In the present specification, 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 surface is referred to as the image side surface of the lens.

[0046] 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 one or more items, the phrase "at least one of" modifies the entire list of items and does not modify the list of items individually. Furthermore, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0047] 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.

[0048] 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 drawings and in conjunction with embodiments.

[0049] The optical lens provided by the embodiments of the present application comprises six lenses, which are sequentially arranged along the optical axis from the object side to the imaging surface as the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens.

[0050] In some embodiments, the first lens can have negative focal power, the object side surface of which is concave, and the image side surface of which is concave. The second lens can have positive focal power, the object side surface of which is convex, and the image side surface of which is concave. The third lens can have positive focal power, the object side surface of which is convex, and the image side surface of which is convex. The fourth lens can have positive focal power, the object side surface of which is concave, and the image side surface of which is convex. The fifth lens can have negative focal power, the object side surface of which is concave, and the image side surface of which is convex. The sixth lens can have positive focal power, the object side surface of which is convex, and the image side surface of which can be concave or convex.

[0051] In some embodiments, the optical lens can further comprise a diaphragm, which can 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 light to change the brightness of the imaging. When the diaphragm is located between the third lens and the fourth lens or between the second lens and the third lens, the correction of the diaphragm aberration is facilitated.

[0052] In some embodiments, the optical lens can further comprise a filter, which is arranged between the sixth lens and the imaging surface. The filter is used to filter out the interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting the normal imaging.

[0053] In some embodiments, the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy: -0.9<(R3-R4) / (R3+R4)<-0.1. By satisfying the above range and by controlling the second lens to have a suitable surface shape, it is beneficial to strengthen the correction of high-order aberrations and to reduce the degree of relative luminance attenuation of the optical lens. At the same time, the second lens adopts a meniscus shape, which is beneficial to correct the distortion of the optical lens. More specifically, -0.87<(R3-R4) / (R3+R4)<-0.14.

[0054] In some embodiments, the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy: -1<(R9-R10) / (R9+R10)<-0.2. By satisfying the above range and by reasonably controlling the surface shape of the fifth lens, it is helpful to further optimize the distortion and the field curvature and to reduce the difficulty of high-order aberration correction of the subsequent lenses. More specifically, -0.91<(R9-R10) / (R9+R10)<-0.3.

[0055] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.3<TTL / f<3.1. By satisfying the above range, the length of the lens can be effectively limited, which is beneficial to realize the miniaturization of the optical lens. More specifically, 2.53<TTL / f<3.04.

[0056] In some embodiments, the total track length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 1.5 < TTL / IH < 2.4. Satisfying the above range ensures that the lens has a larger image surface under the condition of equal total length, which can match a larger imaging chip to realize high-definition imaging, and better realize the balance between small total length and large image surface of the lens. More specifically, 1.59 < TTL / IH < 2.27.

[0057] In some embodiments, the real 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. Satisfying the above range is beneficial to increase the light quantity, so that the peripheral field of view and the central field of view have more uniform brightness. More specifically, 1.84 < IH / EPD < 2.97.

[0058] In some embodiments, the real 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 < IH / f < 1.8. Satisfying the above range controls the image height and focal length of the optical lens within a reasonable range, which is helpful for the optical lens to have the characteristics of large image surface and improve the imaging quality. More specifically, 1.11 < IH / f < 1.66.

[0059] In some embodiments, the real 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) < 1.67. Satisfying the above range can satisfy the optical lens having a large field of view angle and a large image surface while the front aperture is small.

[0060] In some embodiments, the combined focal length ffront of the lenses located in front of the diaphragm and the effective focal length f of the optical lens satisfy: 0.8 < ffront / f < 7; the combined focal length fback of the lenses located behind the diaphragm and the effective focal length f of the optical lens satisfy: 1 < fback / f < 20; the combined focal length ffront of the lenses located in front of the diaphragm and the combined focal length fback of the lenses located behind the diaphragm satisfy: 0 < ffront / fback < 4.2. Satisfying the above range is beneficial to balance various aberrations of the system by reasonably setting the focal lengths of the lens groups before and after the diaphragm, and improve the overall imaging quality. More specifically, 0.86 < ffront / f < 6.62; 1.1 < fback / f < 19.87; 0.03 < ffront / fback < 4.02.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.8 < f1 / f < -0.9; the object-side surface curvature radius R1 of the first lens and the effective focal length f of the optical lens satisfy: -3.5 < R1 / f < -1.1; the image-side surface curvature radius R2 of the first lens and the effective focal length f of the optical lens satisfy: 1.1 < R2 / f < 3.4; the object-side surface curvature radius R1 of the first lens and the image-side surface curvature radius R2 of the first lens satisfy: -0.1 < (R1+R2) / (R1-R2) < 0.4. By setting the first lens to have a negative refractive power and a suitable surface shape, the first lens can collect more light rays with a larger angle and collect as many light rays as possible into the rear optical system, thereby achieving a large field of view while increasing the light flux, when the above ranges are satisfied. More specifically, -2.63 < f1 / f < -0.91; -3.32 < R1 / f < -1.24; 1.16 < R2 / f < 3.12; -0.03 < (R1+R2) / (R1-R2) < 0.36.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 1.3 < f2 / f < 25; the object-side surface curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 0.7 < R3 / f < 5; the image-side surface curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 2.7 < R4 / f < 11. By setting the second lens to have a suitable positive refractive power and a suitable surface shape, the second lens can converge light rays and smoothly guide divergent light rays into the rear optical system, thereby reducing the height of peripheral light rays and facilitating the reduction of the aperture of the rear lens. More specifically, 1.47 < f2 / f < 24.24; 0.74 < R3 / f < 4.7; 2.92 < R4 / f < 10.09.

[0063] 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 < 1; the object-side surface curvature radius R5 of the third lens and the image-side surface curvature radius R6 of the third lens satisfy: -0.4 < (R5+R6) / (R5-R6) < 0.3. By setting the third lens to have a suitable positive refractive power and a suitable surface shape, the third lens can converge light rays and effectively correct the distortion of the edge field of view, thereby reducing the degree of deformation of the edge of the captured image and improving the image quality. More specifically, 0.77 < f3 / f < 0.93; -0.38 < (R5+R6) / (R5-R6) < 0.22.

[0064] 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 < 25. Satisfying the above range, the sixth lens is defined to have positive refractive power, which is conducive to light convergence, smooth transition of light trend to the rear, reduction of the height of light incident to the rear, slowing down of the upward trend of light, avoidance of light energy loss caused by too large angle between the main light ray and the chip when the large field of view light reaches the imaging surface, improvement of the illumination of the edge field of view, and realization of short optical total length. More specifically, 0.67 < f6 / f < 23.46.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 3 < f4 / f < 35; the object side surface curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -3.2; the image side surface curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -3.4 < R8 / f < -1.3; and the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0 < (R7-R8) / (R7+R8) < 0.8. Satisfying the above range is conducive to light convergence, sharing of positive refractive power of the second lens and the third lens, and avoidance of too large light deflection, and better realization of high-quality imaging of the lens. More specifically, 3.22 < f4 / f < 33.44; -14.65 < R7 / f < -3.49; -3.1 < R8 / f < -1.45; and 0.05 < (R7-R8) / (R7+R8) < 0.73.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: -1.7 < f5 / f < -0.6; the object side surface curvature radius R9 of the fifth lens and the effective focal length f of the optical lens satisfy: -0.65 < R9 / f < -0.1; and the image side surface curvature radius R10 of the fifth lens and the effective focal length f of the optical lens satisfy: -12 < R10 / f < -0.3. Satisfying the above range makes the light of the edge field of view have an upward trend, which is conducive to the imaging point on the imaging surface being away from the optical axis, so as to realize the effect of matching with a large chip, obtain a larger picture, effectively eliminate aberration, and improve the resolving power of the optical lens. More specifically, -1.56 < f5 / f < -0.69; -0.61 < R9 / f < -0.15; and -11.62 < R10 / f < -0.31.

[0067] In some embodiments, the effective focal length f of the optical lens, the real 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: 0.8 < (IH / 2) / (f x Tan(FOV / 2)) < 1.13. Satisfying the above range controls the distortion of the optical lens within a reasonable range.

[0068] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.24 < BFL / f < 0.5. Satisfying the above range, the optical lens is limited to have a suitable back focus, the positions of the lenses are reasonably arranged, and the processing and assembling difficulty is reduced.

[0069] In some embodiments, the total track 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 respectively satisfy: 0.57 < ∑CT / TTL < 0.73. Satisfying the above range, the total track length of the optical lens and the sum of the thicknesses of the lenses are reasonably configured, which is helpful to realize high-pixel characteristics and improve the imaging quality of the optical lens.

[0070] 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: 1.51 < ∑CT / f < 2.2. Satisfying the above range, the field curvature and distortion of the optical lens can be effectively corrected, and the imaging quality of the optical lens is improved.

[0071] 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 < 14 mm; 1.6 < Fno < 2; 15° < CRA < 32°; 1 mm < BFL < 2.6 mm; 55° < 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 track 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 real image height corresponding to the maximum field of view angle of the optical lens. Satisfying the above range, the optical lens has at least one or more advantages such as miniaturization, large target surface, large aperture, large field of view angle, and the like. More specifically, 4.12 mm < f < 5.13 mm; 2.25 mm < EPD < 3.11 mm; 11.77 mm < TTL < 13.01 mm; 1.64 < Fno < 1.96; 16.13° < CRA < 31.42°; 1.14 mm < BFL < 2.49 mm; 59° < FOV < 76°; 5.71 mm < IH < 7.39 mm.

[0072] In some embodiments, the lens material in the optical lens provided by the present application can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. 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 application, the first lens and the third lens are glass lenses, and the second lens, the fourth lens, the fifth lens and the sixth lens are plastic lenses. The glass-plastic hybrid structure can effectively reduce the cost, correct the aberration, reduce the size, and provide an optical lens product with higher performance-price ratio.

[0073] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens can be 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 achieving the miniaturization of the lens. More specifically, the first lens and the third lens in the present application are spherical lenses, and the second lens, the fourth lens, the fifth lens and the sixth lens are aspherical lenses.

[0074] In various embodiments of the present application, when the lens is an aspherical lens, 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 from the vertex of the curved surface in the direction of the optical axis, 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 quadratic surface coefficient, and B, C, D, E and F are the fourth-order, sixth-order, eighth-order, tenth-order and twelfth-order surface coefficients, respectively.

[0077] The present application will be further described in the following embodiments. In various embodiments, the thickness, the radius of curvature and 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 preferred embodiments of the present application, but the embodiments of the present application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the present application should be regarded as equivalent replacement methods, and are included in the protection scope of the present application.

[0078] Embodiment 1

[0079] Please refer to Figure 1 , which is a structure schematic diagram of the optical lens 100 provided in the embodiment 1 of the present application. The optical lens 100 includes, in order from the object side to the imaging surface along the optical axis, 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.

[0080] The first lens L1 has negative focal power, the object side S1 is a concave surface, and the image side S2 is a concave surface.

[0081] The second lens L2 has positive focal power, the object side S3 is a convex surface, and the image side S4 is a concave surface.

[0082] The third lens L3 has positive focal power, the object side S5 is a convex surface, and the image side S6 is a convex surface.

[0083] The fourth lens L4 has positive focal power, the object side S7 is a concave surface, and the image side S8 is a convex surface.

[0084] The fifth lens L5 has negative focal power, the object side S9 is a concave surface, and the image side S10 is a convex surface.

[0085] The sixth lens L6 has positive focal power, the object side S11 is a convex surface, and the image side S12 is a convex surface.

[0086] The object side S13 and the image side S14 of the filter G1 are both flat surfaces.

[0087] The imaging surface S15 is a flat surface.

[0088] The first lens L1 and the third lens L3 are glass spherical lenses, and the second lens L2, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are plastic aspherical lenses.

[0089] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0090] Table 1-1

[0091]

[0092] The surface type parameters of the aspherical lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0093] Table 1-2

[0094]

[0095] In this embodiment, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 100 are shown in Figure 2 , Figure 3 respectively.

[0096] Figure 2The F-Tan(Theta) distortion curve of the optical lens 100 is shown in FIG. 1, which represents the distortion of light rays of different wavelengths at different image heights on the imaging plane, and the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the distortion of the optical lens is controlled within 0~13%, which shows that the optical lens 100 can well correct the distortion.

[0097] Figure 3 The MTF (Modulation Transfer Function) curve of the optical lens 100 is shown in FIG. 2, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, and 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 present embodiment is above 0.4 in the full field of view, and in the range of 0~120 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0098] Embodiment 2

[0099] Please refer to Figure 4 , which is a structural schematic diagram of the optical lens 200 provided in the embodiment 2 of the present application. Compared with the 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.

[0100] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0101] Table 2-1

[0102]

[0103] The surface type parameters of the aspherical lens of the optical lens 200 in the embodiment 2 are shown in Table 2-2.

[0104] Table 2-2

[0105]

[0106] In the present embodiment, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 200 are shown in Figure 5 , Figure 6 respectively.

[0107] As can be seen from Figure 5 , the distortion of the optical lens is controlled within 0~13%, which shows that the optical lens 200 can well correct the distortion.

[0108] As can be seen from Figure 6As can be seen, the MTF value of this embodiment is above 0.48 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0109] Example 3

[0110] Please see Figure 7 The figure shown is a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S12 of the sixth lens L6 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0111] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0112] Table 3-1

[0113]

[0114] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0115] Table 3-2

[0116]

[0117] In this embodiment, the F-Tan (Theta) distortion curve and MTF curve of the optical lens 300 are respectively as follows: Figure 8 , Figure 9 As shown.

[0118] from Figure 8 As can be seen, the distortion of the optical lens is controlled within -4% to 0%, indicating that the optical lens 300 can effectively correct distortion.

[0119] from Figure 9 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0120] Example 4

[0121] Please see Figure 10 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side surface S12 of the sixth lens L6 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0122] The related parameters of each lens in the optical lens 400 in Embodiment 4 are shown in Table 4-1.

[0123] Table 4-1

[0124]

[0125] The surface type parameters of the aspherical lens of the optical lens 400 in Embodiment 4 are shown in Table 4-2.

[0126] Table 4-2

[0127]

[0128] In this embodiment, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 400 are shown in Figure 11 , Figure 12 respectively.

[0129] As can be seen from Figure 11 , the distortion of the optical lens is controlled within 0-8%, which indicates that the optical lens 400 can well correct the distortion.

[0130] As can be seen from Figure 12 , the MTF value of this embodiment is above 0.4 in the full field of view, and in 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 has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0131] Embodiment 5

[0132] Please refer to Figure 13 , which is a structural schematic diagram of the optical lens 500 provided in Embodiment 5 of the present application. Compared with Embodiment 1, the main difference is that the diaphragm ST is arranged between the second lens L2 and the third lens L3; the image side surface S12 of the sixth lens L6 is a concave surface; the optical parameters such as the curvature radius and the lens thickness of each lens surface are different.

[0133] The related parameters of each lens in the optical lens 500 in Embodiment 5 are shown in Table 5-1.

[0134] Table 5-1

[0135]

[0136] The surface type parameters of the aspherical lens of the optical lens 500 in Embodiment 5 are shown in Table 5-2.

[0137] Table 5-2

[0138]

[0139] In the present embodiment, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 500 are shown in FIGS. Figure 14 、 Figure 15

[0140] As can be seen from FIG. Figure 14 , the distortion of the optical lens is controlled within-20%~0, which indicates that the optical lens 500 can correct the distortion well.

[0141] As can be seen from FIG. Figure 15 , the MTF value of the present embodiment is above 0.4 in the full field of view, and the MTF curve is uniformly and smoothly decreased from the center to the edge of the field of view in the range of 0~120lp / mm, which has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0142] Referring to Table 6, the optical properties corresponding to the above embodiments are shown, including the effective focal length f, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view, the chief ray angle CRA at the maximum image height, the maximum field of view FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0143] Table 6

[0144]

[0145] In summary of the above embodiments, the optical lens provided by the present application adopts six lenses with specific optical power, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens can be improved, the aberration can be reduced, and the imaging quality of the optical lens can be improved, so that the lens has one or more advantages of miniaturization, large target surface, large aperture, large field of view, high imaging quality, etc.

[0146] In the description of the present specification, the description of the terms "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 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.

[0147] ​The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An optical lens, six pieces of lenses in total, characterized in that, In order from the object side to the imaging surface along the optical axis, successively comprises: a first lens with negative focal length, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a second lens with positive focal length, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a third lens with positive focal length, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a fourth lens with positive focal length, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a fifth lens with negative focal length, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a sixth lens with positive focal length, the object side surface of which is a convex surface; wherein the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy -0.9 < (R3-R4) / (R3+R4) < -0.1; the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy -1 < (R9-R10) / (R9+R10) < -0.2; the optical lens further comprises a diaphragm, the diaphragm is located between the third lens and the fourth lens or between the second lens and the third lens, the combined focal length f of each lens located in front of the diaphragm and the combined focal length f of each lens located behind the diaphragm satisfy 0 < f front / f back < 4.2; 1.6 < Fno < 2, Fno represents the aperture value of the optical lens.

2. The optical lens of 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 < 3.1; the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field angle of the optical lens satisfy 1.5 < TTL / IH < 2.

4.

3. The optical lens of 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; the real image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy 1 < IH / f < 1.

8.

4. The optical lens of claim 1, wherein, the object side surface half light radius d1 of the first lens, the real image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy 0.77 < d1 / (IH / 2) / tan(FOV / 2) < 1.67; the object side surface curvature radius R3 of the second lens and the image side surface curvature radius R4 of the second lens satisfy -0.87 < (R3-R4) / (R3+R4) < -0.14; the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy -0.91 < (R9-R10) / (R9+R10) < -0.3; the optical lens further comprises a diaphragm, the diaphragm is located between the third lens and the fourth lens or between the second lens and the third lens, the combined focal length f of each lens located in front of the diaphragm and the combined focal length f of each lens located behind the diaphragm satisfy 0.03 < f front / f back < 4.02; 1.64 < Fno < 1.96, Fno represents the aperture value of the optical lens.

5. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f1 of the first lens satisfy: -2.8 < f1 / f < -0.9; a curvature radius R1 of an object side surface of the first lens and the effective focal length f of the optical lens satisfy: -3.5 < R1 / f < -1.1; a curvature radius R2 of an image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1.1 < R2 / f < 3.

4.

6. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f2 of the second lens satisfy: 1.3 < f2 / f < 25; a curvature radius R3 of an object side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.7 < R3 / f < 5; a curvature radius R4 of an image side surface of the second lens and the effective focal length f of the optical lens satisfy: 2.7 < R4 / f < 11.

7. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f3 of the third lens satisfy: 0.7 < f3 / f < 1; the effective focal length f of the optical lens and a focal length f6 of the sixth lens satisfy: 0.6 < f6 / f < 25.

8. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f4 of the fourth lens satisfy: 3 < f4 / f < 35; a curvature radius R7 of an object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -3.2; a curvature radius R8 of an image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -3.4 < R8 / f < -1.

3.

9. The optical lens of claim 1, wherein, An effective focal length f of the optical lens and a focal length f5 of the fifth lens satisfy: -1.7 < f5 / f < -0.6; a curvature radius R9 of an object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -0.65 < R9 / f < -0.1; a curvature radius R10 of an image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: -12 < R10 / f < -0.

3.

10. The optical lens of claim 1, wherein, A curvature radius R7 of an object side surface of the fourth lens and a curvature radius R8 of an image side surface of the fourth lens satisfy: 0 < (R7-R8) / (R7+R8) < 0.8; a curvature radius R1 of an object side surface of the first lens and a curvature radius R2 of an image side surface of the first lens satisfy: -0.1 < (R1+R2) / (R1-R2) < 0.4.

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