Optical lens

Abstract

The invention provides an optical lens, which consists of seven lenses, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a convex surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has positive focal power, and the object side surface of the fifth lens is a convex surface; the image side surface is a convex surface; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; and the object side surface of the seventh lens is a convex surface, and the image side surface of the seventh lens is a concave surface. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal 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.

Description

Technical Field

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

[0002] As people's requirements for driving experience continue to increase, the use of in-vehicle application optical lenses in intelligent driving is increasing, and the status of in-vehicle optical lenses in the automotive-related industries continues to improve. In the field of vehicle driving, in order to improve the driving safety and intelligent driving of the vehicle, it is necessary to monitor the vehicle cabin, and OMS (passenger monitoring) vehicle lenses have developed rapidly. The existing in-vehicle cabin monitoring lenses generally have a resolution of about 1M and 2M, and as the lens FOV increases, the angular resolution and resolution drop sharply. In addition to requiring the optical lens to have a thin and light appearance, a small front diameter, high pixels, high resolution and other characteristics, the OMS system lens also requires the optical lens to be able to form clear images under low illumination conditions, so it is necessary to develop an optical lens with good imaging effect. Summary of the invention

[0003] In view of the above problems, an object of the present invention is to provide an optical lens having the advantage of excellent imaging quality.

[0004] The technical solution adopted by the present invention is:

[0005] An optical lens, composed of seven lenses, including the following lenses in order from the object side to the imaging surface along the optical axis:

[0006] The first lens has a negative optical power, the object side surface of which is convex, and the image side surface of which is concave;

[0007] The second lens has a negative optical power, its object side surface is convex, and its image side surface is concave;

[0008] The third lens has positive power, its object side surface is convex, and its image side surface is convex;

[0009] a fourth lens having positive refractive power, whose object-side surface is convex and whose image-side surface is convex;

[0010] The fifth lens has positive refractive power, and its object side surface is convex; its image side surface is convex;

[0011] a sixth lens having negative optical power, whose object side surface is concave and whose image side surface is convex;

[0012] The seventh lens has positive refractive power, its object side surface is convex, and its image side surface is concave;

[0013] The image side surface curvature radius R6 of the third lens and the object side surface curvature radius R7 of the fourth lens satisfy: 0.2<(R6+R7) / (R6-R7)<1.

[0014] More preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.7 < TTL / f < 7; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.3 < TTL / IH < 2.8.

[0015] More preferably, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.3 < IH / EPD < 6; the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < IH / f < 2.9.

[0016] More preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.1 < f1 / f < -1.7; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.8 < f5 / f < 1.

[0017] More preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 6.8 < f3 / f < 9; the object side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: 4.7 < R5 / f < 8.3; the image side curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: -80 < R6 / f < -16.

[0018] More preferably, the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: 1 < f1234 / f567 < 1.3; the image side curvature radius R12 of the sixth lens and the image side curvature radius R14 of the seventh lens satisfy: 0.4 < (R12 + R14) / (R12 - R14) < 0.9.

[0019] More preferably, the focal length f4 of the fourth lens and the focal length f6 of the sixth lens satisfy: -2.85 < f4 / f6 < -2.2; the effective focal length f of the optical lens and the object side curvature radius R7 of the fourth lens satisfy: 6.3 < R7 / f < 8.8; the effective focal length f of the optical lens and the image side curvature radius R12 of the sixth lens satisfy: -7.2 < R12 / f < -4.7.

[0020] Further preferably, the focal length f2 of the second lens and the focal length f7 of the seventh lens satisfy: -1.4 < f2 / f7 < -1; the effective focal length f of the optical lens and the curvature radius R3 of the object side surface of the second lens satisfy: 0.9 < R3 / f < 1.1; the effective focal length f of the optical lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 1 < R14 / f < 1.3.

[0021] Further preferably, the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: -1 < (R5 + R6) / (R5 - R6) < -0.2; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: 0.3 < (R7 + R8) / (R7 - R8) < 0.8.

[0022] Further preferably, the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -1.4 < (R11 + R12) / (R11 - R12) < -1; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: -7.6 < (R13 + R14) / (R13 - R14) < -5.

[0023] Compared with the prior art, the optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and make the lens have one or more advantages such as ultra-wide angle, large aperture, miniaturization, and high pixel. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0025] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0026] Figure 2 is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0027] Figure 3 is an F-Theta distortion curve diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 4 is an axial aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 5 is a lateral chromatic aberration curve diagram of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 6 This is the MTF curve diagram of the optical lens in Example 1 of the present invention.

[0031] Figure 7 Schematic diagram of the structure of the optical lens in Example 2 of the present invention.

[0032] Figure 8 4 is a field curvature curve diagram of the optical lens in Example 2 of the present invention.

[0033] Fig. 9 Graph showing the F-Theta distortion of the optical lens in Embodiment 2 of the present invention.

[0034] Fig.10 Graph showing the axial aberration of the optical lens in Embodiment 2 of the present invention.

[0035] Fig.11 Graph showing the vertical axis chromatic aberration of the optical lens in Example 2 of the present invention.

[0036] Fig.12 This is an MTF curve diagram of the optical lens in Example 2 of the present invention.

[0037] Fig.13 Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0038] Fig.14 4 is a field curvature curve diagram of the optical lens in Example 3 of the present invention.

[0039] Fig.15 Graph showing the F-Theta distortion of the optical lens in Embodiment 3 of the present invention.

[0040] Fig.16 Graph showing the axial aberration of the optical lens in Embodiment 3 of the present invention.

[0041] Fig.17 Graph showing the vertical axis chromatic aberration of the optical lens in Example 3 of the present invention.

[0042] Fig.18 This is the MTF curve diagram of the optical lens in Example 3 of the present invention.

[0043] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0044] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0046] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0047] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0048] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0049] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0050] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0051] The optical lens provided by the embodiment of the present invention is composed of seven lenses, which are a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens in order from the object side to the imaging surface along the optical axis.

[0052] In some embodiments, the first lens may have a negative optical power, with a convex object side surface and a concave image side surface. The second lens may have a negative optical power, with a convex object side surface and a concave image side surface. The third lens may have a positive optical power, with a convex object side surface and a convex image side surface. The fourth lens may have a positive optical power, with a convex object side surface and a convex image side surface. The fifth lens may have a positive optical power, with a convex object side surface and a convex image side surface. The sixth lens may have a negative optical power, with a concave object side surface and a convex image side surface. The seventh lens may have a positive optical power, with a convex object side surface and a concave image side surface.

[0053] In some embodiments, the optical lens may further include an aperture, and the aperture may be located between the fourth lens and the fifth lens. It is understood that the aperture is used to limit the amount of light entering to change the brightness of the image. It is understood that the aperture is used to limit the amount of light entering to change the brightness of the image. When the aperture is located between the fourth lens and the fifth lens, it is convenient to correct the aperture aberration.

[0054] In some embodiments, the optical lens may further include a filter, which may be disposed between the seventh lens and the imaging surface. The filter is used to filter out interference light to prevent the interference light from reaching the imaging surface of the optical lens and affecting normal imaging.

[0055] 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; it can also reduce the assembly sensitivity of the optical lens, thereby reducing the difficulty of the processing technology of the optical lens and improving the assembly yield of the optical lens.

[0056] In some embodiments, the image side curvature radius R6 of the third lens and the object side curvature radius R7 of the fourth lens satisfy: 0.2<(R6+R7) / (R6-R7)<1. Meeting the above range can reduce the light deflection angle and make the light trend more stable; it is beneficial to correct various aberrations of the optical lens and improve the imaging quality of the optical lens. More specifically, 0.42<(R6+R7) / (R6-R7)<0.81.

[0057] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.7 < TTL / f < 7. Meeting the above range can effectively limit the length of the lens, which is conducive to the miniaturization of the optical lens. More specifically, 6.36 < TTL / f < 6.7.

[0058] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.3 < TTL / IH < 2.8. Meeting the above range ensures that, with the same total length of the lens, it has a larger image plane, can match a larger-sized imaging chip to achieve high-definition imaging, and better realizes the balance between the small total length and the large image plane of the lens. More specifically, 2.5 < TTL / IH < 2.63.

[0059] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.3 < IH / EPD < 6. Meeting the above range can increase the width of the light beam incident on the optical lens, improve the brightness of the optical lens at the image plane, and avoid the generation of vignetting. More specifically, 4.73 < IH / EPD < 5.45.

[0060] In some embodiments, the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < IH / f < 2.9. Meeting the above range controls the image height and focal length of the optical lens within a reasonable range, which helps the optical lens to have the characteristic of a large image plane and improves the imaging quality. More specifically, 2.42 < IH / f < 2.68.

[0061] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.1 < f1 / f < -1.7. Meeting the above range, by setting the first lens to have a negative refractive power, it is beneficial for the first lens to collect light at a larger angle and collect as much light as possible into the rear optical system, achieving a large field of view while increasing the light flux. More specifically, -1.96 < f1 / f < -1.91.

[0062] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.8 < f5 / f < 1. Meeting the above conditions, setting the fifth lens to have a positive refractive power is beneficial for converging light while correcting the field curvature and distortion of the optical lens, and improving the imaging quality of the optical lens. More specifically, 0.85 < f5 / f < 0.94.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 6.8 < f3 / f < 9; the radius of curvature R5 of the object side surface of the third lens and the effective focal length f of the optical lens satisfy: 4.7 < R5 / f < 8.3; 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: -80 < R6 / f < -16. Meeting the above ranges is beneficial to the further convergence of light rays, enabling the divergent light rays to smoothly enter the rear optical system and better achieving high-quality imaging of the lens; at the same time, it can effectively correct the distortion of the edge field of view, reduce the degree of deformation of the edge of the captured image, and improve the image quality. More specifically, 7.56 < f3 / f < 8.24; 5.2 < R5 / f < 7.48; -73.62 < R6 / f < -17.69.

[0064] In some embodiments, the combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: 1 < f1234 / f567 < 1.3. Meeting the above range is beneficial to balancing various aberrations of the system and improving the overall imaging quality by reasonably setting the relationship between the lens groups before and after the aperture. More specifically, 1.08 < f1234 / f567 < 1.21.

[0065] In some embodiments, the radius of curvature R12 of the image side surface of the sixth lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: 0.4 < (R12 + R14) / (R12 - R14) < 0.9. Meeting the above range can reduce the light deflection angle, make the light trend smoother; at the same time, it can correct coma and field curvature, improve the flatness of imaging, and improve the imaging quality of the optical lens. More specifically, 0.65 < (R12 + R14) / (R12 - R14) < 0.71.

[0066] In some embodiments, the focal length f4 of the fourth lens and the focal length f6 of the sixth lens satisfy: -2.85 < f4 / f6 < -2.2; the effective focal length f of the optical lens and the radius of curvature R7 of the object side surface of the fourth lens satisfy: 6.3 < R7 / f < 8.8; the effective focal length f of the optical lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -7.2 < R12 / f < -4.7. Meeting the above ranges is beneficial for the object side surface of the fourth lens and the image side surface of the sixth lens to obtain a symmetric surface type, which is beneficial to the correction of various aberrations of the optical lens and improves the imaging quality of the optical lens. More specifically, -2.6 < f4 / f6 < -2.42; 6.97 < R7 / f < 8.02; -6.6 < R12 / f < -5.21.

[0067] In some embodiments, the focal length f2 of the second lens and the focal length f7 of the seventh lens satisfy: -1.4 < f2 / f7 < -1; the effective focal length f of the optical lens and the curvature radius R3 of the object side surface of the second lens satisfy: 0.9 < R3 / f < 1.1; the effective focal length f of the optical lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 1 < R14 / f < 1.3. Meeting the above ranges, the object side surface of the second lens and the image side surface of the seventh lens adopt a lens shape close to concentric circles, which can effectively reduce the optical path difference between the center and the periphery of the lens, and is beneficial to correcting the distortion of the optical lens. More specifically, -1.27 < f2 / f7 < -1.15; 0.95 < R3 / f < 1.03; 1.06 < R14 / f < 1.21.

[0068] In some embodiments, the curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: -1 < (R5 + R6) / (R5 - R6) < -0.2. Meeting the above range is beneficial to the further convergence of light rays, enabling the divergent light rays to smoothly enter the rear optical system, and better realizing the high-quality imaging of the lens; at the same time, it can effectively correct the distortion of the edge field of view, reduce the deformation degree of the edge of the captured image, and improve the image quality. More specifically, -0.88 < (R5 + R6) / (R5 - R6) < -0.4.

[0069] 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 of the fourth lens satisfy: 0.3 < (R7 + R8) / (R7 - R8) < 0.8. Meeting the above range is beneficial to the smooth transition of light rays, can effectively correct the distortion of the edge field of view, reduce the deformation degree of the edge of the captured image, and improve the image quality. More specifically, 0.55 < (R7 + R8) / (R7 - R8) < 0.63.

[0070] In some embodiments, the curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -1.4 < (R11 + R12) / (R11 - R12) < -1. Meeting the above range, controlling the surface shape of the sixth lens, is beneficial to increasing the imaging area and the field of view angle of the optical lens, is beneficial to balancing the aberration of the optical lens, and improving the imaging quality of the optical lens. More specifically, -1.21 < (R11 - R12) / (R11 + R12) < -1.15.

[0071] In some embodiments, the radius of curvature R13 of the object side surface of the seventh lens and the radius of curvature R14 of the image side surface of the seventh lens satisfy: -7.6 < (R13 + R14) / (R13 - R14) < -5. Meeting the above range defines that the seventh lens has a suitable surface shape, enabling the light to transition smoothly to the rear, reducing the height of the light incident on the rear, slowing down the upward trend of the light, avoiding the light energy loss caused by the excessive main ray angle of the large field of view light when reaching the imaging surface, facilitating the improvement of the illuminance of the edge field of view, and being conducive to achieving a short overall optical length. More specifically, -6.91 < (R13 - R14) / (R13 + R14) < -5.61.

[0072] In some embodiments, the maximum field of view FOV of the optical lens and the f-number Fno of the optical lens satisfy: 70° < FOV / Fno < 80°. Meeting the above range defines that the optical lens has a suitable field of view and f-number, capable of collecting light at large angles and obtaining good imaging quality. More specifically, 73.15° < FOV / Fno < 74.43°.

[0073] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.4 < BFL / f < 0.6. Meeting the above range defines that the optical lens has a suitable back focus, facilitating the reasonable arrangement of the positions of each lens and reducing the processing and assembly difficulty at the same time. More specifically, 0.48 < BFL / f < 0.55.

[0074] In some embodiments, the effective focal length f of the optical lens, the maximum field of view FOV of the optical lens, and the true image height IH corresponding to the maximum field of view of the optical lens satisfy: 50° < (f × FOV) / IH < 65°. Meeting the above range, by reasonably restricting the relationship between the focal length, field of view, and image height of the optical lens, it can be ensured that the optical lens has the characteristics of a large field of view and a large image plane, so that the optical lens has good optical performance and can well capture the details of the object to be photographed. More specifically, 56.57° < (f × FOV) / IH < 59.61°.

[0075] In some embodiments, the overall optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.5 < ∑CT / TTL < 0.6. Meeting the above range can effectively compress the overall length of the optical lens, and is conducive to the structural design and production process of the optical lens at the same time. More specifically, 0.55 < ∑CT / TTL < 0.58.

[0076] In some embodiments, the effective focal length f of the optical lens, the radian θ of the maximum half field of view angle, and the true image height IH corresponding to the maximum field of view angle satisfy: 0.95 < (IH / 2) / (f×θ) < 1.02. Meeting the above range is beneficial to realizing the ultra-wide angle characteristic of the optical lens and can control the optical lens to have a small distortion.

[0077] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -4.3 < f2 / f < -3.4. Meeting the above range can control the second lens to have an appropriate negative optical power, which can share the negative optical power at the front end of the optical lens, thereby facilitating avoiding excessive light deflection caused by overly concentrated optical power of the first lens and reducing the difficulty of chromatic aberration correction of the optical lens. More specifically, -3.94 < f2 / f < -3.75.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 1.9 < f4 / f < 2.4. Meeting the above range can effectively converge light, reduce the difficulty of edge field of view distortion correction, ensure that the lens has a small distortion while achieving a large field of view angle, and improve the overall imaging quality. More specifically, 2.13 < f4 / f < 2.17.

[0079] 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 < -0.7. Meeting the above range can effectively balance various aberrations generated by the front lens group, and at the same time is beneficial to increasing the divergence degree of light, increasing the area of light entering the imaging surface, realizing large target surface imaging of the lens, and improving the imaging quality of the optical lens. More specifically, -0.9 < f6 / f < -0.82.

[0080] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 2.8 < f7 / f < 3.6. Meeting the above range can make the seventh lens have an appropriate positive optical power, which is beneficial to balancing the astigmatism of the optical lens and improving the imaging quality of the optical lens. More specifically, 3.12 < f7 / f < 3.25.

[0081] In some embodiments, the sagittal height Sag3 of the object side light-passing semi-aperture of the second lens and the object side light-passing semi-aperture d3 of the second lens satisfy: 0.2 < Sag3 / d3 < 0.3; the sagittal height Sag14 of the image side light-passing semi-aperture of the seventh lens and the image side light-passing semi-aperture d14 of the seventh lens satisfy: 0.2 < Sag14 / d14 < 0.4. Meeting the above range helps to control the trend of edge field of view light and highlight the detailed information of the central field of view of the optical lens. More specifically, 0.22 < Sag3 / d3 < 0.27; 0.26 < Sag14 / d14 < 0.34.

[0082] In some embodiments, the optical lens satisfies the conditional formula: 2mm < f < 2.5mm, 1mm < EPD < 1.3mm, 14mm < TTL < 16mm, 1.8 < Fno < 2.2, 14.3° < CRA < 19.2°, 1mm < BFL < 1.4mm, 130° < FOV < 160°, 5mm < IH < 6.5mm; where f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, and IH represents the true image height corresponding to the maximum field of view angle of the optical lens. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has at least the characteristics of miniaturization, large target surface, large field of view angle, large aperture, etc. More specifically, 2.23mm < f < 2.29mm, 1.09mm < EPD < 1.18mm, 14.5mm < TTL < 15.01mm, 1.94 < Fno < 2.06, 15.79° < CRA < 17.5°, 1.11mm < BFL < 1.24mm, 144° < FOV < 151°, 5.53mm < IH < 5.99mm.

[0083] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected due to the low dispersion characteristic of the glass itself. The first lens and the fourth lens in the optical lens provided by the present invention are made of glass lenses, and the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens are made of plastic lenses. The optical lens of the present invention adopts a glass-plastic hybrid structure to improve the thermal stability.

[0084] 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 spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens and the fourth lens of the present invention adopt spherical lenses, and the second lens, the third lens, the fifth lens, the sixth lens, and the seventh lens can all adopt aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens.

[0085] In each embodiment of the present invention, when the lens adopts an aspherical lens, the surface shapes of the aspherical surfaces of the optical lens satisfy the following equation:

[0086]

[0087] Among them, z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, B, C, D, E, and F are the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order surface coefficients respectively.

[0088] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0089] Example 1

[0090] See also Figure 1 , which is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention, wherein the optical lens includes, in sequence 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 fourth lens L4, an aperture ST, a fifth lens L5, a sixth lens L6, a seventh lens L7 and a filter G1.

[0091] The first lens L1 has negative refractive power, its object side surface S1 is convex, and its image side surface S2 is concave;

[0092] The second lens L2 has negative refractive power, its object-side surface S3 is convex, and its image-side surface S4 is concave;

[0093] The third lens L3 has positive refractive power, its object-side surface S5 is convex, and its image-side surface S6 is convex;

[0094] The fourth lens L4 has positive refractive power, its object-side surface S7 is convex, and its image-side surface S8 is convex;

[0095] The fifth lens L5 has positive refractive power, its object-side surface S9 is convex, and its image-side surface S10 is convex;

[0096] The sixth lens L6 has negative refractive power, its object-side surface S10 is concave, and its image-side surface S11 is convex;

[0097] The fifth lens L5 and the sixth lens L6 form a cemented lens group with positive refractive power, that is, the cemented surface between the image side surface of the fifth lens L5 and the object side surface of the sixth lens L6 is S10;

[0098] The seventh lens L7 has positive refractive power, its object-side surface S12 is convex, and its image-side surface S13 is concave;

[0099] The object side surface S14 and the image side surface S15 of the filter G1 are both planes;

[0100] The imaging surface S16 is a plane.

[0101] The first lens L1 and the fourth lens L4 are glass spherical lenses, and the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6 and the seventh lens L7 are plastic aspherical lenses.

[0102] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0103] Table 1-1

[0104]

[0105]

[0106] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0107] Table 1-2

[0108] Face number K B C D E F S3 -3.75E+00 4.45E-03 -6.89E-03 9.32E-04 1.92E-05 -8.22E-06 S4 -1.06E+00 -1.28E-02 2.68E-03 -3.58E-03 1.04E-03 -8.53E-05 S5 6.23E+01 5.48E-03 -1.73E-03 2.61E-05 -2.92E-04 5.13E-05 S6 -4.50E+01 3.50E-03 -1.85E-03 3.10E-04 -2.08E-04 3.72E-05 S9 8.61E+00 -2.51E-03 5.33E-04 -5.79E-04 1.50E-04 -3.22E-05 S10 -3.94E+00 -1.62E-01 7.11E-02 -2.32E-02 4.31E-03 -3.04E-04 S11 -6.86E+01 -3.63E-02 1.18E-02 -2.11E-03 2.22E-04 -9.08E-06 S12 -3.47E+00 9.47E-03 -2.42E-03 1.73E-04 1.89E-06 -1.57E-06 S13 -9.86E-01 2.02E-03 -4.19E-03 7.88E-04 -8.11E-05 2.85E-06

[0109] Figure 2 The field curvature curve of the optical lens 100 in this embodiment is shown, which indicates the degree of curvature of light in the meridian image plane and the sagittal image plane, the horizontal axis indicates the offset (unit: mm), and the vertical axis indicates the half field angle (unit: °). It can be seen from the figure that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.06mm, indicating that the optical lens 100 can correct the field curvature well.

[0110] Figure 3 The F-Theta distortion curve of the optical lens 100 in this embodiment is shown, which represents the 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: °). It can be seen from the figure that the distortion value is controlled within ±2%, indicating that the optical lens 100 can correct the distortion well.

[0111] Figure 4 The axial aberration curve of the optical lens 100 in this embodiment is shown, which represents the aberration of each wavelength on the optical axis at the imaging surface, the horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. It can be seen from the figure that the offset of the axial aberration is controlled within ±0.02mm, indicating that the optical lens 100 can better correct the axial aberration.

[0112] Figure 5 The vertical axis chromatic aberration curve of the optical lens 100 in this embodiment is shown, which represents the chromatic aberration of each wavelength relative to the central wavelength (0.555 μm) at different image heights on the imaging surface, the horizontal axis represents the vertical axis chromatic aberration value of each wavelength relative to the central wavelength (unit: μm), and the vertical axis represents the normalized field angle. It can be seen from the figure that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±6 μm, indicating that the optical lens 100 can correct the chromatic aberration well.

[0113] Figure 6 The modulation transfer function (MTF) curve of the optical lens 100 in this embodiment is shown, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of this embodiment is above 0.4 in the whole field of view, and in the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency conditions.

[0114] Example 2

[0115] See also Figure 7 , shown is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0116] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0117] Table 2-1

[0118]

[0119] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0120] Table 2-2

[0121] Face number K B C D E F S3 -3.52E+00 4.76E-03 -6.84E-03 9.17E-04 1.62E-05 -5.87E-06 S4 -1.08E+00 -1.38E-02 1.61E-03 -3.93E-03 1.01E-03 -9.01E-05 S5 1.24E+01 3.41E-03 -2.11E-03 -3.25E-04 -4.14E-04 7.76E-05 S6 -1.65E+02 3.17E-03 -2.23E-03 3.16E-04 -1.91E-04 3.82E-05 S9 9.20E+00 -1.95E-03 3.84E-04 -6.70E-04 1.74E-04 -3.15E-05 S10 -3.30E+00 -1.63E-01 7.22E-02 -2.27E-02 4.39E-03 -3.52E-04 S11 -7.65E+01 -3.51E-02 1.17E-02 -2.13E-03 2.25E-04 -9.45E-06 S12 -2.98E+00 8.24E-03 -2.48E-03 1.86E-04 7.99E-07 -1.69E-06 S13 -1.20E+00 1.11E-03 -3.98E-03 7.67E-04 -8.27E-05 3.01E-06

[0122] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, vertical axis chromatic aberration curve, and MTF curve of the optical lens 200 are shown as follows: Figure 8 , Fig. 9 , Fig.10 , Fig.11 , Fig.12 shown.

[0123] from Figure 8It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.05mm, indicating that the optical lens 200 can correct the field curvature well.

[0124] from Fig. 9 It can be seen that the distortion value is controlled within ±4%, indicating that the optical lens 200 can correct the distortion well.

[0125] from Fig.10 It can be seen that the offset of the axial aberration is controlled within ±0.05 mm, indicating that the optical lens 200 can correct the axial aberration well.

[0126] from Fig.11 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5μm, indicating that the optical lens 200 can correct chromatic aberration well.

[0127] from Fig.12 It can be seen that the MTF value of this embodiment is above 0.4 in the whole field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0128] Example 3

[0129] See also Fig.13 , shown is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main difference between this embodiment and Example 1 is that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0130] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0131] Table 3-1

[0132]

[0133]

[0134] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0135] Table 3-2

[0136] Face number K B C D E F S3 -3.95E+00 4.62E-03 -6.85E-03 9.40E-04 2.26E-05 -7.61E-06 S4 -1.09E+00 -1.41E-02 2.21E-03 -3.72E-03 1.02E-03 -8.87E-05 S5 5.12E+01 5.07E-03 -1.97E-03 -6.03E-05 -3.12E-04 5.27E-05 S6 -1.14E+02 3.73E-03 -1.63E-03 3.92E-04 -1.97E-04 3.24E-05 S9 9.30E+00 -1.47E-03 4.17E-04 -6.62E-04 1.70E-04 -3.68E-05 S10 -3.44E+00 -1.68E-01 7.11E-02 -2.28E-02 4.49E-03 -3.29E-04 S11 -9.08E+01 -3.56E-02 1.18E-02 -2.11E-03 2.22E-04 -8.65E-06 S12 -3.21E+00 8.00E-03 -2.34E-03 1.70E-04 1.11E-06 -1.49E-06 S13 -1.07E+00 1.67E-03 -4.22E-03 7.82E-04 -8.13E-05 2.94E-06

[0137] In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, vertical axis chromatic aberration curve, and MTF curve of the optical lens 300 are shown as follows: Fig.14 , Fig.15 , Fig.16 , Fig.17 , Fig.18 shown.

[0138] from Fig.14 It can be seen that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.06mm, indicating that the optical lens 300 can correct the field curvature well.

[0139] from Fig.15 It can be seen that the distortion value is controlled within ±4%, indicating that the optical lens 300 can correct the distortion well.

[0140] from Fig.16 It can be seen that the offset of the axial aberration is controlled within ±0.05 mm, indicating that the optical lens 300 can correct the axial aberration well.

[0141] from Fig.17 It can be seen that the vertical axis chromatic aberration of the longest wavelength and the shortest wavelength is controlled within ±5μm, indicating that the optical lens 300 can correct chromatic aberration well.

[0142] from Fig.18 It can be seen that the MTF value of this embodiment is above 0.4 in the whole field of view. In the range of 0 to 160 lp / mm, the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0143] Please refer to Table 4, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the aperture value Fno, the real image height IH corresponding to the maximum field of view angle, the chief ray incident angle CRA at the maximum image height, the maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0144] Table 4

[0145]

[0146]

[0147] In summary of the above embodiments, the optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape matching and reasonable optical power distribution, it is possible to improve the imaging quality of the optical lens, reduce aberrations, and improve the imaging quality of the optical lens, so that the lens has one or more advantages such as ultra-wide angle, large aperture, miniaturization, and high pixel.

[0148] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0149] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, consisting of seven lenses, characterized in that: It successively includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is convex and whose image side is concave; A second lens with a negative optical power, whose object side is convex and whose image side is concave; A third lens with a positive optical power, whose object side is convex and whose image side is convex; A fourth lens with a positive optical power, whose object side is convex and whose image side is convex; A fifth lens with a positive optical power, whose object side is convex; whose image side is convex; A sixth lens with a negative optical power, whose object side is concave and whose image side is convex; A seventh lens with a positive optical power, whose object side is convex and whose image side is concave; Wherein, the radius of curvature R6 of the image side of the third lens and the radius of curvature R7 of the object side of the fourth lens satisfy: 0.2 < (R6 + R7) / (R6 - R7) < 1.

2. The optical lens according to claim 1, characterized in that: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 5.7 < TTL / f < 7; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.3 < TTL / IH < 2.

8.

3. The optical lens according to claim 1, characterized in that: The true image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 4.3 < IH / EPD < 6; the true image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.2 < IH / f < 2.

9.

4. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.1 < f1 / f < -1.7; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.8 < f5 / f < 1.

5. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 6.8 < f3 / f < 9; the radius of curvature R5 of the object side of the third lens and the effective focal length f of the optical lens satisfy: 4.7 < R5 / f < 8.3; the radius of curvature R6 of the image side of the third lens and the effective focal length f of the optical lens satisfy: -80 < R6 / f < -16.

6. The optical lens according to claim 1, characterized in that: The combined focal length f1234 of the first lens, the second lens, the third lens and the fourth lens and the combined focal length f567 of the fifth lens, the sixth lens and the seventh lens satisfy: 1 < f1234 / f567 < 1.3; the radius of curvature R12 of the image side of the sixth lens and the radius of curvature R14 of the image side of the seventh lens satisfy: 0.4 < (R12 + R14) / (R12 - R14) < 0.

9.

7. The optical lens according to claim 1, characterized in that: The focal length f4 of the fourth lens and the focal length f6 of the sixth lens satisfy: -2.85 < f4 / f6 < -2.2; the effective focal length f of the optical lens and the radius of curvature R7 of the object side of the fourth lens satisfy: 6.3 < R7 / f < 8.8; the effective focal length f of the optical lens and the radius of curvature R12 of the image side of the sixth lens satisfy: -7.2 < R12 / f < -4.

7.

8. The optical lens according to claim 1, characterized in that: The focal length f2 of the second lens and the focal length f7 of the seventh lens satisfy: -1.4 < f2 / f7 < -1; the effective focal length f of the optical lens and the curvature radius R3 of the object side surface of the second lens satisfy: 0.9 < R3 / f < 1.1; the effective focal length f of the optical lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: 1 < R14 / f < 1.

3.

9. The optical lens according to claim 1, characterized in that: The curvature radius R5 of the object side surface of the third lens and the curvature radius R6 of the image side surface of the third lens satisfy: -1 < (R5 + R6) / (R5 - R6) < -0.2; the curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: 0.3 < (R7 + R8) / (R7 - R8) < 0.

8.

10. The optical lens according to claim 1, characterized in that: The curvature radius R11 of the object side surface of the sixth lens and the curvature radius R12 of the image side surface of the sixth lens satisfy: -1.4 < (R11 + R12) / (R11 - R12) < -1; the curvature radius R13 of the object side surface of the seventh lens and the curvature radius R14 of the image side surface of the seventh lens satisfy: -7.6 < (R13 + R14) / (R13 - R14) < -5.

Images