Optical lens

Abstract

The application provides an optical lens, which comprises seven lenses in sequence along an optical axis from an object side to an imaging surface, and the seven 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 convex surface; a third lens with negative focal power, wherein the object side surface is a concave 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 positive focal power, wherein the object side surface is a convex surface, and the image side surface is a convex surface; a sixth lens with negative focal power, wherein the object side surface is a concave surface, and the image side surface is a concave surface; and a seventh lens with positive focal power, wherein the object side surface is a convex surface, and the image side surface is a concave 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 a large target surface, a large aperture, high imaging quality and the like.

Description

TECHNICAL FIELD

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

[0002] With the increasing demand for driving experience, vehicle application optical lenses are increasingly used in intelligent driving, and the status of vehicle optical lenses in the automotive industry is continuously improving.

[0003] Advanced Driver Assistance System (ADAS) plays an important role in intelligent driving, which collects environmental information through various lenses combined with sensors to ensure the safety of drivers. In addition to the requirements of optical lenses for ADAS systems, such as light, thin, small shape and high pixel, high resolution, the optical lenses are also required to have clear imaging under low illumination conditions, so it is necessary to develop an optical lens with good imaging effect. 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:

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

[0007] The first lens has a negative focal length, the object side surface is concave, and the image side surface is concave;

[0008] The second lens has a positive focal length, the object side surface is convex, and the image side surface is convex;

[0009] The third lens has a negative focal length, the object side surface is concave, and the image side surface is convex;

[0010] The fourth lens has a positive focal length, the object side surface is concave, and the image side surface is convex;

[0011] The fifth lens has a positive focal length, the object side surface is convex, and the image side surface is convex;

[0012] The sixth lens has a negative focal length, the object side surface is concave, and the image side surface is concave;

[0013] The seventh lens has a positive focal length, the object side surface is convex, and the image side surface is concave;

[0014] The radius of curvature of the object side surface of the first lens R1 and the radius of curvature of the image side surface of the first lens R2 satisfy: 1.2 < (R1-R2) / (R1+R2) < 1.5; and the radius of curvature of the object side surface of the fourth lens R7 and the radius of curvature of the image side surface of the fourth lens R8 satisfy: 0.8 < (R7-R8) / (R7+R8) < 0.95.

[0015] Further preferably, the total track length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5 < TTL / f < 6.

[0016] Further preferably, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.82 < (IH / 2) / (f*tan(FOV / 2)) < 0.9.

[0017] 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 < 2.1.

[0018] Further preferably, 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 < 1.2.

[0019] Further preferably, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.4 < BFL / f < 0.6.

[0020] Further preferably, the effective focal length f of the optical lens, the radian value θ of the maximum half field of view angle of the optical lens, and the half entrance pupil radius d1 of the object side surface of the first lens satisfy: 0.6 < f*θ / d1 < 0.7.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.6 < f1 / f < -1.5; and the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.7 < f1 / f2 < -0.6.

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.5 < f7 / f < 1.7.

[0023] Further preferably, the radius of curvature of the object side surface of the first lens R1 and the half entrance pupil sag height Sag1 of the object side surface of the first lens satisfy: 77 < R1 / Sag1 < 166.

[0024] The optical lens provided by the present application adopts seven lenses with specific optical power, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages such as large target surface, large aperture, 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 It is a structure schematic diagram of the optical lens in the embodiment 1 of the present application.

[0027] Figure 2 It is a field curvature curve diagram of the optical lens in the embodiment 1 of the present application.

[0028] Figure 3 It is an F-Tan(Theta) distortion curve diagram of the optical lens in the embodiment 1 of the present application.

[0029] Figure 4 It is an MTF curve diagram of the optical lens in the embodiment 1 of the present application.

[0030] Figure 5 It is a structure schematic diagram of the optical lens in the embodiment 2 of the present application.

[0031] Figure 6 It is a field curvature curve diagram of the optical lens in the embodiment 2 of the present application.

[0032] Figure 7 It is an F-Tan(Theta) distortion curve diagram of the optical lens in the embodiment 2 of the present application.

[0033] Figure 8 It is an MTF curve diagram of the optical lens in the embodiment 2 of the present application.

[0034] Figure 9 It is a structure schematic diagram of the optical lens in the embodiment 3 of the present application.

[0035] Figure 10 It is a field curvature curve diagram of the optical lens in the embodiment 3 of the present application.

[0036] Figure 11 It is an F-Tan(Theta) distortion curve diagram of the optical lens in the embodiment 3 of the present application.

[0037] Figure 12 It is an MTF curve diagram of the optical lens in the embodiment 3 of the present application.

[0038] The following detailed description will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0039] For a better understanding of the present application, various aspects of the present application will be described in greater detail below with reference to the accompanying drawings. It is to be noted that these 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 specification, like drawing reference numerals will refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] It should be noted that the terms first, second, third, etc. are used herein only to distinguish one feature from another, and do not denote any limitation on the features. Thus, a first lens discussed below can also be called a second lens or a third lens, without departing from the teachings of the present application.

[0041] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for the sake of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0042] Herein, the paraxial region refers to a region near the optical axis. If a 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 a lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side surface of the lens, and the surface of each lens closest to the image plane is called the image side surface of the lens.

[0043] 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 describing the embodiments of the present application, the use of "may" indicates that one or more embodiments of the present application. Also, the expression "exemplary" is intended to mean example or illustrative.

[0044] 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 will be further understood that terms, such as those defined in commonly used dictionaries, 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.

[0045] It should be noted that the embodiments and features in the embodiments of the present application 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.

[0046] The optical lens provided by the embodiment of the present application comprises seven 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, the sixth lens and the seventh lens.

[0047] In some embodiments, the first lens can have a negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface. The second lens can have a positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface. The third lens can have a negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface. The fourth lens can have a positive focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface. The fifth lens can have a positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface. The sixth lens can have a negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface. The seventh lens can have a positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface.

[0048] In some embodiments, the optical lens can further comprise a diaphragm, which can be located between the third lens and the fourth 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, the correction of the diaphragm aberration is facilitated.

[0049] In some embodiments, the optical lens can further comprise a filter, which and a protective glass are sequentially arranged along the optical axis between the seventh 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. The protective glass plays a role in protecting the optical lens, preventing the photosensitive chip from being damaged, and can improve the impact resistance and scratch resistance of the optical lens, while having little effect on the imaging quality of the optical lens.

[0050] In some embodiments, the fifth lens and the sixth lens can be glued to form a glued lens, which can effectively correct the chromatic aberration of the optical lens, reduce the eccentricity sensitivity of the optical lens, balance the aberration of the optical lens, and improve the imaging quality of the optical lens; and can also reduce the assembly sensitivity of the optical lens, thereby reducing the processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0051] In some embodiments, the object-side surface radius of curvature R1 of the first lens and the image-side surface radius of curvature R2 of the first lens satisfy: 1.2 < (R1-R2) / (R1+R2) < 1.5. Satisfying the above range can make the collected light rays enter the rear optical system in a divergent form as much as possible, while effectively reducing the angle between the edge field of view light rays and the object-side surface of the first lens, improving the overall edge relative luminance of the lens.

[0052] In some embodiments, the object-side surface radius of curvature R7 of the fourth lens and the image-side surface radius of curvature R8 of the fourth lens satisfy: 0.8 < (R7-R8) / (R7+R8) < 0.95. Satisfying the above range can assist in smoothing the light ray trend, and the convex image-side surface can converge light rays, reducing the total optical length.

[0053] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5 < TTL / f < 6. Satisfying the above range is conducive to miniaturization and long focal length of the entire lens.

[0054] In some embodiments, the effective focal length f of the optical lens, the maximum field of view angle FOV of the optical lens, and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 0.82 < (IH / 2) / (f*tan(FOV / 2)) < 0.9. Satisfying the above range can control the optical lens to have smaller distortion, and improve the imaging quality of the optical lens.

[0055] 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 < 2.1. Satisfying the above range is conducive to increasing the light flux, so that the peripheral field of view and the central field of view have more uniform brightness.

[0056] 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 < 1.2. Satisfying the above range controls the image height and focal length of the optical lens to be within a reasonable range, which is helpful for the optical lens to have a large image surface and improve the imaging quality.

[0057] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.4 < BFL / f < 0.6. Satisfying the above range limits the optical lens to have a suitable back focus, which is conducive to reasonable arrangement of the positions of the lenses, while reducing the difficulty of processing and assembly.

[0058] 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 seventh lens along the optical axis respectively satisfy: 0.85 < ∑CT / TTL < 0.95. Satisfying the above range, reasonably configuring the total track length of the optical lens and the sum of the thicknesses of the lenses, the high-pixel characteristics can be achieved, and the imaging quality of the optical lens is improved.

[0059] In some embodiments, the effective focal length f of the optical lens, the radian value θ of the maximum half field angle of the optical lens, and the half entrance pupil diameter d1 of the object side of the first lens satisfy: 0.6 < f x θ / d1 < 0.7. Satisfying the above range, controlling the focal length of the optical lens, the radian value corresponding to the maximum half field angle of the lens, and the front diameter of the lens, the balance of the focal length, the field of view, and the diameter of the lens can be achieved.

[0060] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.6 < f1 / f < -1.5. Satisfying the above range, the first lens has a negative refractive power, and the light passing through it can have a diverging effect, which is beneficial to achieve a small front diameter.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: 2 < f2 / f < 3. Satisfying the above range, the second lens is limited to have an appropriate positive refractive power, which has the effect of converging light, and is matched with the negative refractive power of the first lens, which can further converge the light passing through the first lens, and reduce the height of the peripheral light, which is beneficial to the reduction of the diameter of the rear lens, while balancing the aberration and improving the resolution.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: f3 / f < -540. Satisfying the above range, the light rays are diverged, which can disperse the central light and the edge light of each field of view, so that the rear optical system has a larger light receiving surface to receive the light emitted from the image side of the third lens, which realizes a larger light amount and is beneficial to increase the relative illumination.

[0063] 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 < 4. Satisfying the above range, the light rays are converged, which makes the diverging light rays smoothly enter the rear optical system, and better realizes high-quality imaging of the lens; at the same time, the distortion of the edge field of view can be effectively corrected, the deformation degree of the edge of the photographed picture is reduced, and the picture quality is improved.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.6 < f5 / f < 1.75. Satisfying the above range, the fifth lens is defined to have appropriate positive refractive power, which is conducive to light convergence. And the cooperation of the fifth lens with positive refractive power and the sixth lens with negative refractive power can adjust the optical path difference between different fields of view, improve resolution, and is conducive to making the light enter the rear lens gently, which can further reduce the field curvature and correct the off-axis point aberration of the optical lens.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1 < f6 / f < -0.9. Satisfying the above range, the sixth lens is defined to have appropriate negative refractive power, which can diverge the light emitted by the fifth lens and make the light of the edge field have an upward trend, so as to be conducive to realizing the effect of matching with a large chip, obtaining a larger picture, effectively eliminating aberration, and improving the resolving power of the optical lens.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.5 < f7 / f < 1.7. Satisfying the above range, the seventh lens is defined to have positive refractive power, which is conducive to light convergence, makes the light trend transition to the rear smoothly, reduces the height of the light incident to the rear, slows down the upward trend of the light, avoids the light energy loss caused by the large angle of the main light of the chip when the light of the large field of view reaches the imaging surface, is conducive to improving the illumination of the edge field, and is conducive to realizing a short total optical length.

[0067] In some embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.7 < f1 / f2 < -0.6. Satisfying the above range, the refractive powers of the first lens and the second lens are controlled to be positive and negative, which is conducive to balancing aberration and improving resolution; further, the ratio of the two is controlled within the conditional range, which is conducive to the smooth light trend and reduces sensitivity.

[0068] In some embodiments, the object side surface curvature radius R1 of the first lens and the object side surface half-diameter sag1 of the first lens satisfy: 77 < R1 / Sag1 < 166. Satisfying the above range, the ratio of the object side surface half-diameter sag1 and the curvature radius is controlled, which is conducive to reducing the angle between the light of the edge field and the object side surface of the first lens when the light is incident, and improving the overall edge relative illumination of the lens.

[0069] In some embodiments, the air gap CT34 of the third lens and the fourth lens on the optical axis satisfies: 0.15 < CT34 / TTL < 0.25, where TTL is the total optical length of the optical lens. The air gap between the third lens and the fourth lens is controlled to facilitate smooth transition of light rays and improve imaging quality under the premise of miniaturization. Further, the optical sensitivity of the optical lens can be further reduced when the air gap is relatively large.

[0070] In some embodiments, the optical lens satisfies the following conditions: 7mm < f < 8mm; 60° < FOV < 75°; 4mm < EPD < 5mm; 38mm < TTL < 41mm; 1.5 < Fno < 1.8; 8mm < IH < 9mm; 25° < CRA < 30°; 3mm < BFL < 4mm. In the above conditions, f represents the effective focal length of the optical lens, FOV represents the maximum field of view 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, IH represents the real image height corresponding to the maximum field of view of the optical lens, CRA represents the chief ray incidence angle at the maximum image height of the optical lens, and BFL represents the back focal length of the optical lens. The optical lens at least has one or more advantages such as large target surface, large aperture, and long focal length.

[0071] 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 by the low dispersion characteristics of the glass. The optical lens provided by the present application can adopt a full-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0072] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens can adopt a spherical lens or an aspherical lens. Compared with a spherical structure, an 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 miniaturization of the lens. More specifically, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens of the present application adopt a spherical lens, and the seventh lens adopts an aspherical lens.

[0073] In various embodiments of the present application, when the lens adopts an aspherical lens, the shape of each aspherical surface of the optical lens satisfies the following equation:

[0074]

[0075] Wherein, z is the distance of the curved surface and the curved surface vertex 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 curved surface vertex, K is the quadratic curved surface coefficient, B, C, D, E, F are the fourth order, sixth order, eighth order, tenth order, twelfth order curved surface coefficients respectively.

[0076] 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.

[0077] Embodiment 1

[0078] Please refer to Figure 1 , which is a structural schematic diagram of the optical lens 100 provided in the embodiment 1 of the application, the optical lens 100 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, a seventh lens L7 and a filter G1.

[0079] The first lens L1 has negative focal power, the object side surface S1 thereof is a concave surface, and the image side surface S2 thereof is a concave surface;

[0080] The second lens L2 has positive focal power, the object side surface S3 thereof is a convex surface, and the image side surface S4 thereof is a convex surface;

[0081] The third lens L3 has negative focal power, the object side surface S5 thereof is a concave surface, and the image side surface S6 thereof is a convex surface;

[0082] The fourth lens L4 has positive focal power, the object side surface S7 thereof is a concave surface, and the image side surface S8 thereof is a convex surface;

[0083] The fifth lens L5 has positive focal power, the object side surface S9 thereof is a convex surface, and the image side surface S10 thereof is a convex surface;

[0084] The sixth lens L6 has negative focal power, the object side surface S10 thereof is a concave surface, and the image side surface S11 thereof is a concave surface;

[0085] The fifth lens L5 and the sixth lens L6 constitute a cemented lens group, that is, the cemented surface of the image side surface of the fifth lens L5 and the object side surface of the sixth lens L6 is S10;

[0086] The seventh lens L7 has positive focal power, the object side surface S12 thereof is a convex surface, and the image side surface S13 thereof is a concave surface;

[0087] The object side S14 and the image side S15 of the filter G1 are both planar surfaces;

[0088] The object side S16 and the image side S17 of the protective glass G2 are both planar surfaces;

[0089] The imaging surface S18 is a planar surface.

[0090] The seventh lens L7 is a glass aspheric lens, and the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are glass spherical lenses.

[0091] The related parameters of the lenses in the optical lens 100 in Embodiment 1 are shown in Table 1-1.

[0092] Table 1-1

[0093]

[0094]

[0095] The surface type parameters of the aspheric lenses of the optical lens 100 in Embodiment 1 are shown in Table 1-2.

[0096] Table 1-2

[0097] Face number K B C D E F S12 -1.82E+00 8.14E-04 5.14E-06 -7.75E-08 5.38E-09 1.23E-10 S13 1.76E+00 8.82E-04 5.75E-06 5.44E-06 -4.42E-07 1.96E-08

[0098] In this embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 100 are shown in FIGS. Figure 2 、 Figure 3 、 Figure 4

[0099] Figure 2 The field curvature curve of Embodiment 1 is shown, which represents the curvature degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.02 mm, which shows that the optical lens can well correct the field curvature.

[0100] Figure 3 The F-Tan(Theta) distortion curve of Embodiment 1 is shown, which represents the distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field angle (unit: °). It can be seen from the figure that the distortion of the optical lens is controlled within -15%~0, which shows that the optical lens can well correct the distortion.

[0101] Figure 4 ​The MTF (Modulation Transfer Function) curve of the embodiment 1 is shown, which represents the lens imaging modulation degree of 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. It can be seen from the figure that the MTF value of the embodiment is above 0.6 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.

[0102] Embodiment 2

[0103] Please refer to Figure 5 , 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.

[0104] The related parameters of each lens in the optical lens 200 in the embodiment 2 are shown in Table 2-1.

[0105] Table 2-1

[0106]

[0107] The surface type parameters of the aspherical lens of the optical lens 200 in the embodiment 2 are shown in Table 2-2.

[0108] Table 2-2

[0109] Face number K B C D E F S12 -1.84E+00 8.13E-04 5.25E-06 -8.44E-08 5.10E-09 1.94E-10 S13 1.35E+00 8.68E-04 3.95E-06 5.30E-06 -4.45E-07 2.01E-08

[0110] In the embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 200 are shown in Figure 6 , Figure 7 , Figure 8 respectively.

[0111] It can be seen from Figure 6 that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.02 mm, which indicates that the optical lens can well correct the field curvature.

[0112] It can be seen from Figure 7 that the distortion of the optical lens is controlled within -17%~0, which indicates that the optical lens can well correct the distortion.

[0113] It can be seen from Figure 8 that the MTF value of the embodiment is above 0.6 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.

[0114] Embodiment 3

[0115] Please refer to Figure 9 , which is a structural schematic diagram of the optical lens 300 provided in Embodiment 3 of the present application. 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.

[0116] The related parameters of each lens in the optical lens 300 in Embodiment 3 are shown in Table 3-1.

[0117] Table 3-1

[0118]

[0119]

[0120] The surface type parameters of the aspherical lens of the optical lens 300 in Embodiment 3 are shown in Table 3-2.

[0121] Table 3-2

[0122] Face number K B C D E F S12 -1.08E+00 3.90E-04 6.48E-06 -2.09E-08 -1.07E-09 1.77E-10 S13 1.20E+01 4.77E-04 -1.07E-05 4.71E-06 -3.75E-07 1.34E-08

[0123] In this embodiment, the field curvature curve, the F-Tan(Theta) distortion curve and the MTF curve of the optical lens 300 are shown in Figure 10 , Figure 11 , Figure 12 respectively.

[0124] As can be seen from Figure 10 , the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.02 mm, which indicates that the optical lens can well correct the field curvature.

[0125] As can be seen from Figure 11 , the distortion of the optical lens is controlled within -15%~0, which indicates that the optical lens can well correct the distortion.

[0126] As can be seen from Figure 12 , the MTF value of this embodiment is above 0.6 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.

[0127] Please refer to Table 4, which is the optical characteristics corresponding to each of the above embodiments, 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 of incidence CRA at the maximum image height, the maximum field of view FOV and the numerical value corresponding to each conditional expression in each embodiment of the optical lens.

[0128] Table 4

[0129]

[0130]

[0131] In summary, the optical lens provided by the present application adopts seven lenses with specific optical powers, and through specific surface shape matching and reasonable optical power distribution, the imaging quality of the optical lens is improved, the aberration is reduced, and the imaging quality of the optical lens is improved, so that the lens has one or more advantages such as large target surface, large aperture, high imaging quality, etc.

[0132] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like 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.

[0133] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to 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, in total seven pieces of lenses, characterized in that, In order from the object side to the imaging surface along the optical axis, sequentially comprises: a first lens with negative refractive power, 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 refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a third lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a fourth lens with positive refractive power, 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 positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a sixth lens with negative refractive power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; a seventh lens with positive refractive power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; wherein the object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: 1.2<(R1-R2) / (R1+R2)<1.5; the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0.8<(R7-R8) / (R7+R8)<0.95; 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<2.

1.

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: 5<TTL / f<6.

3. The optical lens of claim 1, wherein, the effective focal length f of the optical lens, the maximum field angle FOV of the optical lens, and the real image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.82<(IH / 2) / (fxtan(FOV / 2))<0.

9.

4. The optical lens of claim 1, wherein, the object side surface curvature radius R1 of the first lens and the image side surface curvature radius R2 of the first lens satisfy: 1.29≤(R1-R2) / (R1+R2)≤1.48; the object side surface curvature radius R7 of the fourth lens and the image side surface curvature radius R8 of the fourth lens satisfy: 0.83≤(R7-R8) / (R7+R8)≤0.90; 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: 1.8≤IH / EPD≤2.

01.

5. The optical lens of claim 1, wherein, 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.

2.

6. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.4<BFL / f<0.

6.

7. The optical lens of claim 1, wherein, the effective focal length f of the optical lens, the radian value θ of the maximum half field angle of the optical lens, and the object side surface half light entrance radius d1 of the first lens satisfy: 0.6<f×θ / d1<0.

7.

8. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -1.6<f1 / f<-1.5; the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -0.7<f1 / f2<-0.

6.

9. The optical lens of claim 1, wherein, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.5<f7 / f<1.

7.

10. The optical lens of claim 1, wherein, A radius of curvature R1 of an object side surface of the first lens and a sagittal height Sag1 of the object side surface of the first lens satisfy: 77 < R1 / Sag1 < 166.

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