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 optical power, wherein the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a concave surface; a second lens with negative optical power, wherein the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a convex surface; a third lens with positive optical power, wherein the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; a fourth lens with positive optical power, wherein the object side surface and the image side surface of the fourth lens are both convex surfaces; a fifth lens with positive optical power, wherein the object side surface of the fifth lens is a convex surface, and the image side surface of the fifth lens is a concave surface; a sixth lens with negative optical power, wherein the image side surface of the sixth lens is a concave surface; and a seventh lens with positive optical power; the object side surface curvature radius R9 of the fifth lens and the image side surface curvature radius R10 of the fifth lens satisfy: -0.85<(R9-R10) / (R9+R10)<-0.4. The optical lens provided by the application has one or more advantages of a large field of view, a large target surface, a large aperture, high imaging quality and the like through specific surface shape matching and reasonable optical power distribution.

Description

Technical Field

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

[0002] As people's demands for driving experience continue to increase, automotive optical lenses are being used more and more in intelligent driving, and the status of automotive optical lenses in the automotive industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play a crucial role in intelligent driving. They use various lenses and sensors to collect environmental information to ensure driver safety. Existing ADAS lenses not only require a slim and compact design with high pixel count and high resolution, but also need to produce clear images in low-light conditions. Therefore, it is necessary to develop an optical lens with excellent imaging performance. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an optical lens with the advantage of excellent image quality.

[0005] The technical solution adopted in this invention is as follows:

[0006] An optical lens comprises seven lenses, arranged sequentially along the optical axis from the object side to the imaging plane:

[0007] The first lens with negative optical power has a convex object side and a concave image side.

[0008] A second lens with negative optical power has a concave object side and a convex image side.

[0009] A third lens with positive optical power has a convex object-side surface and a concave image-side surface.

[0010] The fourth lens with positive optical power has convex surfaces on both its object side and image side.

[0011] The fifth lens with positive optical power has a convex object side and a concave image side.

[0012] The sixth lens has negative optical power and its image-side surface is concave.

[0013] A seventh lens with positive optical power;

[0014] The object-side radius of curvature R9 of the fifth lens and the image-side radius of curvature R10 of the fifth lens satisfy: -0.85<(R9-R10) / (R9+R10)<-0.4.

[0015] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.4 < TTL / f < 9; the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 3.9 < TTL / IH < 4.1.

[0016] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 87° < FOV / Fno < 91°; the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.3 < IH / EPD < 3.7.

[0017] Further preferably, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.3; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.7 < BFL / f < 1.4.

[0018] Further preferably, the clear aperture d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.55 < d1 / (IH / 2) / tan(FOV / 2) < 0.64; the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: 2.2 < f4567 / f < 3.3.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -29 < f2 / f < -24; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.7 < f6 / f < -1.7.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 7.3; the object side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R5 / f < 6.2; the image side curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 17 < R6 / f < 440.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.4 < f4 / f < 3.1; the object side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.9 < R7 / f < 3.4; the image side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -1.9.

[0022] More preferably, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.5 < f7 / f < 19; 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: 0.23 < R13 / R14 < 5.4.

[0023] More preferably, the clear aperture semi-diameter d9 of the object side surface of the fifth lens and the sagittal height Sag9 of the clear aperture of the object side surface of the fifth lens satisfy: 0.2 < Sag9 / d9 < 0.35; the clear aperture semi-diameter d10 of the image side surface of the fifth lens and the sagittal height Sag10 of the clear aperture of the image side surface of the fifth lens satisfy: 0.01 < Sag10 / d10 < 0.09.

[0024] The optical lens provided by the present invention adopts seven lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberration, and improve the imaging quality of the optical lens, enabling the lens to have one or more advantages such as a large viewing angle, a large target surface, a large aperture, and high imaging quality. Brief Description of the Drawings

[0025] 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, where:

[0026] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention;

[0027] Figure 2 is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 1 of the present invention;

[0028] Figure 3 is the MTF curve graph of the optical lens in Embodiment 1 of the present invention;

[0029] Figure 4 is the axial aberration curve graph of the optical lens in Embodiment 1 of the present invention;

[0030] Figure 5 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention;

[0031] Figure 6 is the F-Tan(Theta) distortion curve of the optical lens in Embodiment 2 of the present invention;

[0032] Figure 7 is the MTF curve graph of the optical lens in Embodiment 2 of the present invention;

[0033] Figure 8This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 9 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0035] Figure 10 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 3 of the present invention.

[0036] Figure 11 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0037] Figure 12 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 13 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0039] Figure 14 This is the F-Tan (Theta) distortion curve of the optical lens in Embodiment 4 of the present invention.

[0040] Figure 15 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0041] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0042] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0043] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this 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.

[0044] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0045] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0046] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity 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 location of the concaveness 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 subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0047] It should also be understood that the terms "comprising," "including," "having," "containing," 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. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0048] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] The optical lens provided in this embodiment of the invention has a total of seven lenses, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens.

[0051] In some embodiments, the first lens may have negative optical power, with its object-side surface being convex and its image-side surface being concave. The second lens may have negative optical power, with its object-side surface being concave and its image-side surface being convex. The third lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave. The fourth lens may have positive optical power, with both its object-side and image-side surfaces being convex. The fifth lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave. The sixth lens may have negative optical power, with its object-side surface being either concave or convex, and its image-side surface being concave. The seventh lens may have positive optical power, with its object-side surface being either concave or convex, and its image-side surface being either concave or convex.

[0052] In some embodiments, the optical lens may also include an aperture stop, which may be located between the third and fourth lenses. It is understood that the aperture stop is used to limit the amount of light entering the lens, thereby changing the brightness of the image. Furthermore, when the aperture stop is located between the third and fourth lenses, it can rationally allocate the functions of the first to seventh lenses. For example, the first, second, and third lenses can be used to receive light to a greater extent, while the fourth to seventh lenses can be used to correct aberrations, which is beneficial for balancing the overall structure of the optical system. In addition, when the aperture stop is located between the third and fourth lenses, it facilitates the correction of aperture aberrations.

[0053] In some embodiments, the optical lens may further include a filter and a protective glass, which are sequentially disposed between the seventh lens and the imaging plane along the optical axis. The filter is used to filter out interfering light, preventing it from reaching the imaging plane of the optical lens and affecting normal imaging. The protective glass protects the optical lens, preventing damage to the image sensor, and improves the lens's shock and scratch resistance, while having almost no impact on the image quality.

[0054] In some embodiments, the object-side radius of curvature R9 of the fifth lens and the image-side radius of curvature R10 of the fifth lens satisfy: -0.85 < (R9 - R10) / (R9 + R10) < -0.4. Meeting this range facilitates light convergence, ensuring a smooth transition of light rays to the rear, which is beneficial for correcting aberrations in the entire optical lens and improving its imaging quality. Simultaneously, it reduces the height of incident light rays, mitigating the upward trend of the light and preventing light energy loss caused by excessive angles between large field-of-view rays and the chip's principal ray when reaching the imaging surface, thus improving the illumination at the edge of the field of view. More specifically, -0.81 < (R9 - R10) / (R9 + R10) < -0.41.

[0055] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.4 < TTL / f < 9. Meeting the above range can effectively limit the length of the lens and is conducive to the miniaturization of the optical lens. More specifically, 8.42 < TTL / f < 8.97.

[0056] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 3.9 < TTL / IH < 4.1. 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, 3.98 < TTL / IH < 4.02.

[0057] In some embodiments, the maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 87° < FOV / Fno < 91°. Meeting the above range defines that the optical lens has an appropriate field angle and f-number, can collect light at a large angle, and obtain good imaging quality. More specifically, 87.92° < FOV / Fno < 90.69°.

[0058] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.3 < IH / EPD < 3.7. Meeting the above range can increase the width of the light beam entering the optical lens, improve the brightness at the image plane of the optical lens, and avoid the generation of vignetting. More specifically, 3.36 < IH / EPD < 3.63.

[0059] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.3. Meeting the above range controls the image height and focal length of the optical lens within a reasonable range, helps the optical lens to have the characteristic of a large image plane, and improves the imaging quality. More specifically, 2.1 < IH / f < 2.26.

[0060] In some embodiments, the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.7 < BFL / f < 1.4. Meeting the above range defines that the optical lens has an appropriate back focus, facilitates the reasonable arrangement of the positions of each lens, and at the same time reduces the processing and assembly difficulty. More specifically, 0.73 < BFL / f < 1.31.

[0061] In some embodiments, the clear aperture d1 of the object side surface of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.55 < d1 / (IH / 2) / tan(FOV / 2) < 0.64. Meeting the above range can have a small front aperture while meeting the requirements of the optical lens having a large field angle and a large image plane.

[0062] In some embodiments, the combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens, and the seventh lens and the effective focal length f of the optical lens satisfy: 2.2 < f4567 / f < 3.3. Meeting the above range is beneficial to balancing various aberrations generated by the lens group before the aperture by reasonably setting the relationship of the lens group after the aperture, and improving the overall imaging quality. More specifically, 2.22 < f4567 / f < 3.27.

[0063] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -29 < f2 / f < -24; the radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: -2.6 < R3 / f < -1.9; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: -3.6 < R4 / f < -2.8. Meeting the above range enables the second lens to have a negative optical power and a suitable surface shape, which can share the negative optical power at the front end of the optical lens, thus helping to avoid excessive light deflection caused by excessive concentration of the optical power of the first lens and reducing the difficulty of aberration correction of the optical lens. More specifically, -28.21 < f2 / f < -24.53; -2.59 < R3 / f < -1.99; -3.58 < R4 / f < -2.88.

[0064] In some embodiments, the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.7 < f6 / f < -1.7. Meeting the above range can effectively balance various aberrations generated by the previous lens group, and at the same time is beneficial to increasing the divergence degree of light, increasing the area of light entering the imaging plane, realizing large target surface imaging of the lens, and improving the imaging quality of the optical lens. More specifically, -2.61 < f6 / f < -1.74.

[0065] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 7.3; 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: 2.3 < R5 / f < 6.2; 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: 17 < R6 / f < 440. Meeting the above ranges defines that the third lens has an appropriate positive optical power and a suitable surface shape, has the effect of converging light, reduces the height of peripheral light, is beneficial to reducing the aperture of the rear lens, and is also beneficial to balancing aberrations and improving resolution. More specifically, 4.56 < f3 / f < 7.3; 2.33 < R5 / f < 6.17; 17.99 < R6 / f < 439.93.

[0066] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.4 < f4 / f < 3.1; the radius of curvature R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 1.9 < R7 / f < 3.4; the radius of curvature R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -1.9. Meeting the above ranges defines that the fourth lens has an appropriate positive optical power and a biconvex surface shape, further converges light, is beneficial to making the light enter the rear lens smoothly, can adjust the optical path difference between different fields of view, and improves resolution. More specifically, 2.41 < f4 / f < 3.01; 1.9 < R7 / f < 3.31; -2.59 < R8 / f < -1.93.

[0067] In some embodiments, the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.5 < f7 / f < 19; 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: 0.23 < R13 / R14 < 5.4. Meeting the above ranges sets that the seventh lens has a positive refractive power and a suitable surface shape, is beneficial to light convergence, makes the light trend transition smoothly to the rear, reduces the height of the light incident on the rear, avoids the light energy loss caused by the excessive main ray angle of the large field of view light reaching the imaging surface, is beneficial to improving the illuminance of the edge field of view, and is also beneficial to achieving a short optical total length. More specifically, 3.52 < f7 / f < 18.02; 0.23 < R13 / R14 < 5.31.

[0068] In some embodiments, the clear aperture semi-diameter d9 of the object side surface of the fifth lens and the sagittal height Sag9 of the clear aperture of the object side surface of the fifth lens satisfy: 0.2 < Sag9 / d9 < 0.35; the clear aperture semi-diameter d10 of the image side surface of the fifth lens and the sagittal height Sag10 of the clear aperture of the image side surface of the fifth lens satisfy: 0.01 < Sag10 / d10 < 0.09. Meeting the above ranges helps to control the trend of light rays in the marginal field of view and highlight the detailed information of the central field of view of the optical lens.

[0069] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis satisfy: 0.46 < ∑CT / TTL < 0.58. Meeting the above range can effectively compress the total length of the optical lens and is beneficial to the structural design and production process of the optical lens.

[0070] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the seventh lens along the optical axis and the effective focal length f of the optical lens satisfy: 4.1 < ΣCT / f < 4.9. Meeting the above range can effectively correct the field curvature and distortion of the optical lens and improve the imaging quality of the optical lens. More specifically, 4.14 < ΣCT / f < 4.89.

[0071] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.3 < f1 / f < -1.9. Meeting the above range, by setting the first lens to have a negative refractive power, it is beneficial for the first lens to accommodate a larger angle of light rays and collect as much light as possible into the rear optical system, achieving a large field of view while increasing the light flux. More specifically, -2.29 < f1 / f < -1.95.

[0072] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 2.9 < f5 / f < 6.8; the radius of curvature R9 of the object side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 1.5 < R9 / f < 2.6; the radius of curvature R10 of the image side surface of the fifth lens and the effective focal length f of the optical lens satisfy: 5.9 < R10 / f < 22. Meeting the above ranges, setting the fifth lens to have a positive refractive power and a suitable surface shape is beneficial for converging light rays while correcting the aberration of the optical lens and improving the imaging quality of the optical lens. More specifically, 2.96 < f5 / f < 6.76; 1.56 < R9 / f < 2.59; 5.91 < R10 / f < 21.57.

[0073] In some embodiments, the radius of curvature R5 of the object side surface of the third lens and the radius of curvature R6 of the image side surface of the third lens satisfy: -0.98 < (R5 - R6) / (R5 + R6) < -0.7. Meeting the above range is beneficial to balancing the aberration generated by the front lens, facilitating the correction of the aberration of the entire optical lens, and improving the imaging quality of the optical lens.

[0074] In some embodiments, the optical lens satisfies the following conditional expressions: 4 mm < f < 4.3 mm; 140° < FOV < 150°; 2.5 mm < EPD < 2.7 mm; 35 mm < TTL < 37 mm; 1.55 < Fno < 1.65; 8.7 mm < IH < 9.1 mm; 15° < CRA < 27°; 3 mm < BFL < 5.4 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, FOV represents the maximum field angle 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 true image height corresponding to the maximum field angle of the optical lens, CRA represents the chief ray angle of incidence of the optical lens, and BFL represents the back focal length of the optical lens. Meeting the above range, the optical lens has at least one or more advantages such as a large field angle, a large target surface, and a large aperture. More specifically, 4.04 mm < f < 4.24 mm; 2.5 mm < EPD < 2.65 mm; 35.03 mm < TTL < 36.27 mm; 1.59 < Fno < 1.64; 15.55° < CRA < 26.67°; 3.05 mm < BFL < 5.31 mm; 141° < FOV < 147°; 8.74 mm < IH < 9.1 mm.

[0075] 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. When the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected by the low dispersion characteristic of the glass itself. The optical lens provided by the present invention can adopt an all-glass lens structure, which can reduce dispersion, effectively correct the chromatic aberration of the optical lens, and improve the imaging quality.

[0076] 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 fourth lens of the present invention adopts an aspherical lens; the first lens, the second lens, the third lens, the fifth lens, and the sixth lens adopt spherical lenses; the seventh lens can adopt a spherical lens or an aspherical lens.

[0077] In various embodiments of the present invention, when an aspherical lens is used, the shapes of each aspherical surface of the optical lens satisfy the following equations:

[0078]

[0079] Where 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 vertex of the surface, K is the quadratic surface coefficient, and B, C, D, E, and F are the fourth, sixth, eighth, tenth, and twelfth order surface coefficients, respectively.

[0080] The present invention will be further described below with reference to several 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 tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered as equivalent substitutions and are included within the protection scope of the present invention.

[0081] Example 1

[0082] Please see Figure 1 The diagram shows a schematic of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, along the optical axis from the object side to the imaging plane, the following components in sequence: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, a filter G1, and a protective glass G2.

[0083] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0084] The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is convex.

[0085] The third lens L3 has positive optical power, its object side S5 is convex, and its image side S6 is concave.

[0086] The fourth lens L4 has positive optical power, and both its object-side surface S7 and image-side surface S8 are convex.

[0087] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side S10 is concave.

[0088] The sixth lens L6 has negative optical power, its object side S11 is convex, and its image side S12 is concave.

[0089] The seventh lens L7 has positive optical power, its object side S13 is concave, and its image side S14 is convex.

[0090] The object-side surface S15 and the image-side surface S16 of filter G1 are both planar.

[0091] The object side S17 and image side S18 of the protective glass G2 are both flat.

[0092] The imaging plane S19 is a plane.

[0093] The fourth lens L4 is a glass aspherical lens; the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, and the seventh lens L7 are glass spherical lenses.

[0094] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0095] Table 1-1

[0096]

[0097]

[0098] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0099] Table 1-2

[0100] Face number K B C D E F S7 -2.84E-01 -9.93E-04 4.29E-05 -1.10E-05 9.04E-07 -2.87E-08 S8 2.99E+00 4.08E-04 -1.25E-05 9.33E-07 -3.51E-08 7.87E-10

[0101] In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and axial aberration curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 As shown.

[0102] Figure 2 The F-Tan (Theta) distortion curve of Example 1 is shown, which represents the F-Tan (Theta) distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the F-Tan (Theta) distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tan (Theta) distortion of the optical lens is controlled within -70% to 0, and the image compression in the edge angle region is relatively smooth, effectively improving the sharpness of the unfolded image.

[0103] Figure 3The MTF (Modulation Transfer Function) curve of Example 1 is shown, which represents the lens imaging modulation at different spatial frequencies in various fields of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of this example is above 0.35 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and uniformly from the center to the edge of the field of view, exhibiting good imaging quality and good detail resolution at both low and high frequencies.

[0104] Figure 4 The axial aberration curve of Example 1 is shown, which represents the aberration of each wavelength on the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the figure, the axial aberration offset is controlled within -0.02 mm to 0.05 mm, indicating that the optical lens can correct axial aberration well.

[0105] Example 2

[0106] Please see Figure 5 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S13 of the seventh lens L7 is a convex surface; the image side surface S14 of the seventh lens L7 is a concave surface; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0107] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0108] Table 2-1

[0109]

[0110] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0111] Table 2-2

[0112]

[0113]

[0114] In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and axial aberration curve of the optical lens 200 are respectively as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0115] from Figure 6As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -70% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.

[0116] from Figure 7 As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0117] from Figure 8 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0118] Example 3

[0119] Please see Figure 9 The figure shown is a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the object side surface S11 of the sixth lens L6 is concave; the object side surface S13 of the seventh lens L7 is convex; the image side surface S14 of the seventh lens L7 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0120] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0121] Table 3-1

[0122]

[0123]

[0124] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0125] Table 3-2

[0126] Face number K B C D E F S7 -1.78E+01 -3.45E-04 1.09E-04 -3.59E-05 3.56E-06 -1.36E-07 S8 1.71E+00 2.17E-04 2.72E-06 -1.03E-06 7.84E-08 -2.12E-09

[0127] In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and axial aberration curve of the optical lens 300 are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown.

[0128] from Figure 10 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -65% to 0, indicating that the optical lens can correct distortion well.

[0129] from Figure 11 As can be seen, the MTF value of this embodiment is above 0.35 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0130] from Figure 12 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0131] Example 4

[0132] Please see Figure 13 The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the seventh lens is a glass aspherical lens; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0133] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4.

[0134] Table 4-1

[0135]

[0136]

[0137] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0138] Table 4-2

[0139] Face number K B C D E F S7 1.18E+00 -7.56E-04 2.38E-05 -4.98E-06 2.06E-07 -3.99E-09 S8 3.54E+00 7.47E-04 -2.30E-05 2.57E-06 -1.54E-07 4.17E-09 S13 -4.97E+01 -6.70E-04 -4.93E-05 -1.90E-07 5.22E-08 0.00E+00 S14 -1.86E+01 8.67E-05 -8.07E-06 7.34E-07 4.68E-08 0.00E+00

[0140] In this embodiment, the F-Tan (Theta) distortion curve, MTF curve, and axial aberration curve of the optical lens 400 are respectively as follows: Figure 14 , Figure 15 , Figure 16 As shown.

[0141] from Figure 14 As can be seen, the F-Tan (Theta) distortion of the optical lens is controlled within -65% to 0, and the image compression in the edge angle area is relatively smooth, which effectively improves the clarity of the unfolded image.

[0142] from Figure 15As can be seen, the MTF value of this embodiment is above 0.4 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0143] from Figure 16 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.03mm, indicating that the optical lens can effectively correct axial aberration.

[0144] Please refer to Table 5 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0145] Table 5

[0146]

[0147]

[0148] In summary, the optical lens provided by the present invention employs seven lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as a large field of view, a large target surface, a large aperture, and high imaging quality.

[0149] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0150] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising seven lenses, characterized in that, It sequentially 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 concave and whose image side is convex; A third lens with a positive optical power, whose object side is convex and whose image side is concave; A fourth lens with a positive optical power, both of whose object side and image side are convex; A fifth lens with a positive optical power, whose object side is convex and whose image side is concave; A sixth lens with a negative optical power, whose image side is concave; A seventh lens with a positive optical power; Among them, the curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: -0.85 < (R9 - R10) / (R9 + R10) < -0.4; The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.4 < TTL / f < 9; The total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 3.9 < TTL / IH < 4.

1.

2. The optical lens according to claim 1, characterized in that, The curvature radius R9 of the object side of the fifth lens and the curvature radius R10 of the image side of the fifth lens satisfy: -0.81 < (R9 - R10) / (R9 + R10) < -0.41; The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 8.42 < TTL / f < 8.97; The total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 3.98 < TTL / IH < 4.

02.

3. The optical lens according to claim 1, characterized in that, The maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 87° < FOV / Fno < 91°; The true image height IH corresponding to the maximum field angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 3.3 < IH / EPD < 3.

7.

4. The optical lens according to claim 1, characterized in that, The true image height IH corresponding to the maximum field angle of the optical lens and the effective focal length f of the optical lens satisfy: 2.1 < IH / f < 2.3; The effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.7 < BFL / f < 1.

4.

5. The optical lens according to claim 1, characterized in that, The clear aperture d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.55 < d1 / (IH / 2) / tan(FOV / 2) < 0.64; The combined focal length f4567 of the fourth lens, the fifth lens, the sixth lens and the seventh lens and the effective focal length f of the optical lens satisfy: 2.2 < f4567 / f < 3.

3.

6. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -29 < f2 / f < -24; The effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -2.7 < f6 / f < -1.

7.

7. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 4.5 < f3 / f < 7.3; the object-side curvature radius R5 of the third lens and the effective focal length f of the optical lens satisfy: 2.3 < R5 / f < 6.2; the image-side curvature radius R6 of the third lens and the effective focal length f of the optical lens satisfy: 17 < R6 / f < 440.

8. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.4 < f4 / f < 3.1; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: 1.9 < R7 / f < 3.4; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -2.6 < R8 / f < -1.

9.

9. The optical lens according to claim 1, characterized in that, The effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 3.5 < f7 / f < 19; the object-side curvature radius R13 of the seventh lens and the image-side curvature radius R14 of the seventh lens satisfy: 0.23 < R13 / R14 < 5.

4.

10. The optical lens according to claim 1, characterized in that, The object-side clear aperture semi-diameter d9 of the fifth lens and the object-side clear aperture sagitta Sag9 of the fifth lens satisfy: 0.2 < Sag9 / d9 < 0.35; the image-side clear aperture semi-diameter d10 of the fifth lens and the image-side clear aperture sagitta Sag10 of the fifth lens satisfy: 0.01 < Sag10 / d10 < 0.09.

Images