Optical lens

Abstract

The invention provides an optical lens, which comprises eight lenses from an object side to an imaging surface along an optical axis: 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, the object side surface of the second lens is a concave surface; the third lens has positive focal power; the object side surface of the fourth lens is a concave surface, and the image side surface of the fourth lens is a convex surface; the fifth lens has positive focal power, and the image side surface of the fifth lens 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 concave surface; the seventh lens has positive focal power, and the object side surface of the seventh lens is a convex surface; the object side surface of the eighth lens is a concave surface, and the image side surface of the eighth lens is a convex surface. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of an ultra-wide angle, a large image plane, a large aperture, high imaging quality and the like.

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, automotive optical lenses are increasingly used in intelligent driving, and the status of automotive optical lenses in the automotive-related industries continues to improve.

[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 systems require not only a thin, compact form factor with high pixel count and resolution, but also the ability to produce clear images in low-light conditions. Therefore, developing an optical lens with excellent imaging performance is crucial. Summary of the Invention

[0004] 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.

[0005] The technical solution adopted in the present invention is:

[0006] An optical lens, comprising eight lenses, including the following elements in order from the object side to the imaging surface along the optical axis:

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

[0008] a second lens having negative optical power and a concave object-side surface;

[0009] a third lens having positive optical power;

[0010] a fourth lens element having positive refractive power, whose object-side surface is concave and whose image-side surface is convex;

[0011] a fifth lens element having positive refractive power and a convex image-side surface;

[0012] a sixth lens element having negative optical power, whose object-side surface and image-side surface are concave;

[0013] a seventh lens element having positive refractive power and a convex object-side surface;

[0014] an eighth lens element having positive refractive power, whose object-side surface is concave and whose image-side surface is convex;

[0015] Among them, 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 < (R7 - R8) / (R7 + R8) < 0.9; the curvature radius R15 of the object side surface of the eighth lens and the curvature radius R16 of the image side surface of the eighth lens satisfy: 0.1 < (R15 - R16) / (R15 + R16) < 1.

[0016] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6.1 < TTL / f < 8.5; 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: 2.7 < TTL / IH < 3.6.

[0017] Further preferably, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 75° < FOV / Fno < 100°; 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: 3.1 < IH / EPD < 4.3.

[0018] 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: 1.8 < IH / f < 2.6; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.64 < BFL / f < 1.85.

[0019] Further preferably, 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: 0.4 < d1 / (IH / 2) / tan(FOV / 2) < 0.71; the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.5 < f45678 / f < 5.5.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.9 < f1 / f < -1.5; the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 4 < R1 / f < 14; the curvature radius R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1 < R2 / f < 1.4.

[0021] Further preferably, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -70 < f2 / f < -2.5; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.8 < f3 / f < 6.

[0022] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.8 < f4 / f < 15.8; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -3.5; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -4.5 < R8 / f < -1.5.

[0023] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.2 < f5 / f < 3; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1 < f6 / f < -0.7; the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.2 < f7 / f < 2.5.

[0024] Further preferably, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 2.7 < f8 / f < 40; the object-side curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -70 < R15 / f < -8.5; the image-side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: -16 < R16 / f < -2.1.

[0025] The optical lens provided by the present invention adopts eight 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, improve the imaging quality of the optical lens, and endow the lens with one or more advantages such as ultra-wide angle, large image plane, large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a schematic structural diagram of the optical lens in Embodiment 1 of the present invention.

[0028] Figure 2 is a MTF curve graph of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 3 is a schematic structural diagram of the optical lens in Embodiment 2 of the present invention.

[0030] Figure 4 is a MTF curve graph of the optical lens in Embodiment 2 of the present invention.

[0031] Figure 5Schematic diagram of the structure of the optical lens in Example 3 of the present invention.

[0032] Figure 6 This is the MTF curve of the optical lens in Example 3 of the present invention.

[0033] Figure 7 Schematic diagram of the structure of the optical lens in Example 4 of the present invention.

[0034] Figure 8 This is the MTF curve of the optical lens in Example 4 of the present invention.

[0035] Figure 9 Schematic diagram of the structure of the optical lens in Example 5 of the present invention.

[0036] Figure 10 This is the MTF curve of the optical lens in Example 5 of the present invention.

[0037] Figure 11 Schematic diagram of the structure of the optical lens in Example 6 of the present invention.

[0038] Figure 12 This is the MTF curve of the optical lens in Example 6 of the present invention.

[0039] Figure 13 Schematic diagram of the structure of the optical lens in Example 7 of the present invention.

[0040] Figure 14 This is the MTF curve of the optical lens in Example 7 of the present invention.

[0041] Figure 15 Schematic diagram of the structure of the optical lens in Example 8 of the present invention.

[0042] Figure 16 This is the MTF curve of the optical lens in Example 8 of the present invention.

[0043] Figure 17 Schematic diagram of the structure of the optical lens in Example 9 of the present invention.

[0044] Figure 18 This is an MTF curve diagram of the optical lens in Example 9 of the present invention.

[0045] Figure 19 Schematic diagram of the structure of the optical lens in Example 10 of the present invention.

[0046] Figure 20 This is an MTF curve diagram of the optical lens in Example 10 of the present invention.

[0047] Figure 21 Schematic diagram of the structure of the optical lens in Example 11 of the present invention.

[0048] Figure 22 This is the MTF curve of the optical lens in Example 11 of the present invention.

[0049] Figure 23 Schematic diagram of the structure of the optical lens in Example 12 of the present invention.

[0050] Figure 24 This is the MTF curve of the optical lens in Example 12 of the present invention.

[0051] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0052] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of 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.

[0053] It should be noted that in this specification, the terms "first," "second," "third," etc., are used solely to distinguish one feature from another and do not limit the features. Thus, the first lens discussed below could also be referred to as the second lens or the third lens without departing from the teachings of the present invention.

[0054] In the drawings, the thickness, size, and shape of the lenses are slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical and aspherical surfaces shown in the drawings are provided by way of example. That is, the shapes of the spherical and aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0055] In this article, the paraxial region refers to the area near the optical axis. If a lens surface is convex and the location of the convex surface is undefined, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the location of the concave surface is undefined, 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.

[0056] 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 preclude 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 list of 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.

[0057] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0058] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this 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.

[0059] The optical lens provided by the embodiment of the present invention comprises eight lenses, which are arranged in order from the object side to the imaging surface along the optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens.

[0060] In some embodiments, the first lens may have negative optical power, its object-side surface is convex, and its image-side surface is concave. The second lens may have negative optical power, its object-side surface is concave, and its image-side surface may be concave or convex. The third lens may have positive optical power, its object-side surface may be concave or convex, and its image-side surface may be concave or convex. The fourth lens may have positive optical power, its object-side surface is concave, and its image-side surface is convex. The fifth lens may have positive optical power, its object-side surface may be concave or convex, and its image-side surface may be convex. The sixth lens may have negative optical power, its object-side surface is concave, and its image-side surface is concave. The seventh lens may have positive optical power, its object-side surface is convex, and its image-side surface may be concave or convex. The eighth lens may have positive optical power, its object-side surface is concave, and its image-side surface is convex.

[0061] In some embodiments, the optical lens may further include an aperture, which may be located between the third and fourth lens elements. It is understood that the aperture is used to limit the amount of light entering, thereby changing the brightness of the image. When the aperture is located between the third and fourth lens elements, it facilitates correction of aperture aberrations.

[0062] In some embodiments, the optical lens may further include a filter and a protective glass, which may be sequentially disposed between the eighth lens and the imaging surface along the optical axis. The filter is used to filter out interfering light to prevent it from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass serves to protect the optical lens and prevent the photosensitive chip from being damaged and affecting the imaging effect of the lens.

[0063] In some embodiments, the fifth lens, the sixth lens, and the seventh lens may be glued together to form a cemented 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 processing difficulty of the optical lens and improving the assembly yield of the optical lens.

[0064] [[ID=**6**]]In some embodiments, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0 < (R7 - R8) / (R7 + R8) < 0.9. Meeting the above range can make the fourth lens have a meniscus shape, which is beneficial to improving the light-gathering ability of the optical lens, and at the same time can balance various aberrations generated by the optical lens and improve the imaging quality of the optical lens. More specifically, 0.11 < (R7 - R8) / (R7 + R8) < 0.78.

[0065] [[ID=**9**]]In some embodiments, the radius of curvature R15 of the object side surface of the eighth lens and the radius of curvature R16 of the image side surface of the eighth lens satisfy: 0.1 < (R15 - R16) / (R15 + R16) < 1. Meeting the above range is beneficial to suppressing the angle of incidence of the marginal field of view on the imaging surface, effectively transmitting more light beams to the imaging surface, and at the same time can balance the field curvature and spherical aberration of the optical lens and improve the imaging quality of the optical lens. More specifically, 0.29 < (R15 - R16) / (R15 + R16) < **0.89**

[0066] [[ID=**12**]]In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6.1 < TTL / f < 8.5. Meeting the above range can effectively limit the length of the lens and is beneficial to the miniaturization of the optical lens. More specifically, 6.78 < TTL / f < **7.83**

[0067] [[ID=**15**]]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: 2.7 < TTL / IH < 3.6. Meeting the above range ensures that the lens has a larger image surface under the same total length of the lens, can match a larger-size imaging chip to achieve high-definition imaging, and better realizes the balance of the small total length and the large image surface of the lens. More specifically, 3 < TTL / IH < **3.34**

[0068] Note: The numbers in bold are the parts that seem to be inconsistent or might need further clarification in the original text. The translation is done as per the given rules while maintaining the original format and content as closely as possible.In some embodiments, the maximum field of view (FOV) of the optical lens and the f-number (Fno) of the optical lens satisfy: 75° < FOV / Fno < 100°. Meeting the above range defines that the optical lens has an appropriate field of view and f-number, can collect light at large angles, and obtain good imaging quality. More specifically, 79° < FOV / Fno < 92.28°.

[0069] In some embodiments, the true image height (IH) corresponding to the maximum field of view of the optical lens and the entrance pupil diameter (EPD) of the optical lens satisfy: 3.1 < IH / EPD < 4.3. Meeting the above range can increase the width of the light beam incident on the optical lens, improve the brightness at the image plane of the optical lens, and avoid vignetting. More specifically, 3.48 < IH / EPD < 3.92.

[0070] In some embodiments, the true image height (IH) corresponding to the maximum field of view of the optical lens and the effective focal length (f) of the optical lens satisfy: 1.8 < IH / f < 2.6. Meeting the above range controls the image height and focal length of the optical lens within a reasonable range, which helps the optical lens have the characteristic of a large image plane and improve the imaging quality. More specifically, 2.04 < IH / f < 2.43.

[0071] In some embodiments, the effective focal length (f) of the optical lens and the back focal length (BFL) of the optical lens satisfy: 0.64 < BFL / f < 1.85. Meeting the above range defines that the optical lens has an appropriate back focus, which is convenient for reasonably arranging the positions of each lens and reduces the processing and assembly difficulty.

[0072] 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 of view of the optical lens, and the maximum field of view (FOV) of the optical lens satisfy: 0.4 < d1 / (IH / 2) / tan(FOV / 2) < 0.71. Meeting the above range can have a small front aperture while meeting the requirements of the optical lens having a large field of view and a large image plane.

[0073] In some embodiments, the combined focal length (f45678) of the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens and the effective focal length (f) of the optical lens satisfy: 1.5 < f45678 / f < 5.5. Meeting the above range, by reasonably setting the relationship of the lens group behind the aperture, it is beneficial to balance various aberrations generated by the lens group in front of the aperture and improve the overall imaging quality. More specifically, 1.65 < f45678 / f < 5.05.

[0074] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.9 < f1 / f < -1.5; the radius of curvature R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: 4 < R1 / f < 14; the radius of curvature R2 of the image side surface of the first lens and the effective focal length f of the optical lens satisfy: 1 < R2 / f < 1.4. Meeting the above ranges, by setting the first lens to have a negative refractive power and a suitable surface shape, it is beneficial for the first lens to receive light at a larger angle and collect as much light as possible to enter the rear optical system, increasing the light flux while achieving a large field of view. More specifically, -2.63 < f1 / f < -1.62; 4.37 < R1 / f < 13.02; 1.11 < R2 / f < 1.33.

[0075] In some embodiments, the effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -70 < f2 / f < -2.5; 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: -3.4 < R3 / f < -1.5. Meeting the above ranges, the second lens has a negative optical power and a concave object side surface, which has the effect of diverging light. At the same field angle, the light emerging from the image side surface of the first lens is further diverged, and the central light and edge light of each field can be dispersed, enabling the rear optical system to have a larger light receiving surface to receive the light emerging from the image side surface of the second lens, achieving a larger light input, and being beneficial for increasing the relative illumination. More specifically, -68.04 < f2 / f < -2.69; -3.1 < R3 / f < -1.68.

[0076] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.8 < f3 / f < 6. Meeting the above ranges, it is specified that the third lens has an appropriate positive optical power and has the effect of converging light, reducing the height of peripheral light, which is beneficial for reducing the aperture of the rear lens. More specifically, 2.04 < f3 / f < 5.53.

[0077] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.8 < f4 / f < 15.8; 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: -15 < R7 / f < -3.5; 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: -4.5 < R8 / f < -1.5. Meeting the above ranges, the fourth lens adopts a positive optical power and a suitable surface shape, which can further focus light, adjust the angle of the chief ray, optimize the imaging quality, and correct residual aberrations (such as distortion, chromatic aberration, etc.), reducing the distortion of the wide-angle lens. More specifically, 3.12 < f4 / f < 14.4; -13.91 < R7 / f < -3.83; -4.21 < R8 / f < -1.64.

[0078] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.2 < f5 / f < 3; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1 < f6 / f < -0.7; the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.2 < f7 / f < 2.5. Meeting the above ranges, defining that the fifth and seventh lenses have appropriate positive optical powers and the sixth lens has an appropriate negative optical power can adjust the optical path difference between different fields of view, improve the resolution, facilitate the gentle entry of light into the rear lenses, further reduce the field curvature, and correct the off-axis aberration of the optical lens. 1.33 < f5 / f < 2.79; -0.92 < f6 / f < -0.72; 1.35 < f7 / f < 2.37.

[0079] In some embodiments, the effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 2.7 < f8 / f < 40; the object-side curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -70 < R15 / f < -8.5; the image-side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: -16 < R16 / f < -2.1. Meeting the above ranges, setting the eighth lens to have a positive refractive power and an appropriate surface shape is beneficial for light convergence, enabling the light trend to smoothly transition 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 light when reaching the imaging surface, facilitating the improvement of the illuminance of the edge field of view, and being beneficial for achieving a short overall optical length. More specifically, 2.9 < f8 / f < 36.35; -67.03 < R15 / f < -9.19; -14.67 < R16 / f < -2.34.

[0080] In some embodiments, the effective focal length f of the optical lens and the image-side curvature radius R10 of the fifth lens satisfy: -2.7 < R10 / f < -1.1; the effective focal length f of the optical lens and the object-side curvature radius R11 of the sixth lens satisfy: -2.7 < R!1 / f < -1.1. Meeting the above ranges is beneficial for balancing the aberration of the optical lens and improving the imaging quality of the optical lens. More specifically, -2.49 < R10 / f < -1.21; -2.49 < R11 / f < -1.21.

[0081] In some embodiments, the effective focal length f of the optical lens and the image-side curvature radius R12 of the sixth lens satisfy: 0.7 < R12 / f < 1.3; the effective focal length f of the optical lens and the object-side curvature radius R13 of the seventh lens satisfy: 0.7 < R13 / f < 1.3. Meeting the above ranges is beneficial to balancing the aberrations of the optical lens and improving the imaging quality of the optical lens. More specifically, 0.8 < R12 / f < 1.23; 0.8 < R13 / f < 1.3.

[0082] In some embodiments, the optical lens satisfies the following conditional expressions: 5 mm < f < 7 mm; 3.2 mm < EPD < 4 mm; 40 mm < TTL < 50 mm; 1.5 < Fno < 1.8; 13° < CRA < 24°; 4 mm < BFL < 12 mm; 130° < FOV < 160°; 13 mm < IH < 14 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the total optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray angle of incidence of the optical lens, BFL represents the back focal length of the optical lens, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as ultra-wide angle, large target surface, and large aperture. More specifically, 5.62 mm < f < 6.66 mm; 3.48 mm < EPD < 3.92 mm; 41.1 mm < TTL < 45.46 mm; 1.55 < Fno < 1.71; 13.4° < CRA < 23.83°; 4.32 mm < BFL < 11.11 mm; 135.5° < FOV < 150.5°; 13.61 mm < IH < 13.67 mm.

[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 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.

[0084] In some embodiments, the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses may be spherical or aspherical lenses. Compared to spherical lenses, aspherical structures can effectively reduce aberrations in the optical system, thereby reducing the number and size of lenses and achieving better miniaturization. More specifically, the fourth and eighth lenses of the present invention are aspherical lenses, while the first, second, third, fifth, sixth, and seventh lenses are spherical lenses.

[0085] In various embodiments of the present invention, when the lens is an aspheric lens, the shapes of the aspheric surfaces of the optical lens satisfy the following equations:

[0086]

[0087] Where z is the distance between the surface and the vertex 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, and 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 illustrated below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens vary; for details, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any other changes, substitutions, combinations, or simplifications that do not deviate from the novelties of the present invention shall be considered equivalent replacements and are included within the scope of protection of the present invention.

[0089] Example 1

[0090] See also Figure 1 , shown is a schematic structural diagram of the optical lens 100 provided in Example 1 of the present invention. The optical lens 100 includes, in order from the object side to the imaging surface along the optical axis: a first lens L1, a second lens L2, a third lens L3, an aperture ST, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1, and a protective glass G2.

[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 concave, and its image-side surface S4 is convex;

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

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

[0096] The sixth lens L6 has negative refractive power, and its object-side surface and image-side surface are concave.

[0097] The seventh lens L7 has positive refractive power, its object-side surface is convex, and its image-side surface S12 is concave;

[0098] The fifth lens L5, the sixth lens L6, and the seventh lens L7 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 L7 is S10, and the cemented surface between the image-side surface of the sixth lens L6 and the object-side surface of the seventh lens L7 is S11.

[0099] The eighth lens L8 has positive refractive power, its object-side surface S13 is concave, and its image-side surface S14 is convex;

[0100] The object-side surface S15 and the image-side surface S16 of the filter G1 are both flat surfaces;

[0101] The object side surface S17 and the image side surface S18 of the protective glass G2 are both flat surfaces;

[0102] The imaging surface S19 is a plane.

[0103] The fourth lens L4 and the eighth lens L8 are glass aspherical lenses; 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.

[0104] Table 1 shows the parameters of the lenses in the optical lens 100 in Example 1.

[0105] Table 1

[0106]

[0107] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0108] Table 1-2

[0109] Face number K B C D E F S7 2.00E+02 -1.58E-04 9.37E-07 1.42E-07 -6.12E-09 1.21E-10 S8 1.33E+01 6.86E-05 3.90E-06 1.69E-08 -1.85E-09 7.47E-11 S13 -2.00E+02 -1.19E-03 -2.26E-05 -2.32E-08 -2.59E-08 2.99E-10 S14 -1.96E+01 -8.74E-04 -1.30E-05 3.10E-07 -1.08E-08 1.44E-10

[0110] Figure 2The MTF (Modulation Transfer Function) curve for Example 1 is shown, representing the degree of lens imaging modulation at different spatial frequencies across the field of view. The horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the graph, the MTF value of this embodiment is consistently above 0.2 across the entire field of view. Within 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, demonstrating excellent imaging quality and detail resolution at both low and high frequencies.

[0111] Example 2

[0112] See also Figure 3 , shown is a schematic structural diagram of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image-side surface S14 of the seventh lens L7 is a convex surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0113] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0114] Table 2-1

[0115]

[0116] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0117] Table 2-2

[0118] Face number K B C D E F S7 1.03E+02 -2.00E-04 -8.76E-07 0.00E+00 0.00E+00 0.00E+00 S8 1.30E+01 -9.98E-05 8.98E-07 -7.35E-08 2.62E-09 -2.96E-11 S13 -2.00E+02 -1.07E-03 -1.71E-05 1.83E-07 -9.20E-09 2.14E-11 S14 4.29E+01 -7.57E-04 -9.87E-06 3.00E-07 -6.37E-09 3.46E-11

[0119] from Figure 4 It can be seen that the MTF value of this embodiment is above 0.38 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0120] Example 3

[0121] See also Figure 5 , shown is a schematic structural diagram of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences between this embodiment and Example 1 are: the image-side surface S6 of the third lens L3 is convex; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0122] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0123] Table 3-1

[0124]

[0125] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0126] Table 3-2

[0127] Face number K B C D E F S7 1.74E+02 -3.72E-04 -1.47E-06 6.36E-08 -1.99E-09 3.92E-11 S8 9.40E+00 -2.46E-04 1.32E-06 9.86E-09 1.91E-10 1.24E-11 S13 -2.00E+02 -8.51E-04 -2.28E-06 -5.60E-07 2.45E-08 -5.19E-10 S14 -5.67E+00 -6.01E-04 -3.30E-06 -8.96E-08 4.62E-09 -1.12E-10

[0128] from Figure 6 It can be seen that the MTF value of this embodiment is above 0.2 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0129] Example 4

[0130] See also Figure 7 , shown is a schematic structural diagram of an optical lens 400 provided in Example 4 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S6 of the third lens L3 is a convex surface; the image-side surface S14 of the seventh lens L7 is a convex surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0131] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0132] Table 4-1

[0133]

[0134] The surface parameters of the aspheric lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0135] Table 4-2

[0136] Face number K B C D E F S7 1.32E+02 -4.79E-04 -2.55E-07 0.00E+00 0.00E+00 0.00E+00 S8 1.25E+01 -3.17E-04 5.53E-07 1.22E-07 -4.06E-09 7.77E-11 S13 -8.77E+01 -7.63E-04 -6.44E-06 1.37E-07 -8.37E-09 1.02E-10 S14 2.85E+01 -5.01E-04 -2.72E-06 1.64E-07 -4.72E-09 4.82E-11

[0137] from Figure 8 It can be seen that the MTF value of this embodiment is above 0.3 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0138] Example 5

[0139] See also Figure 9 , shown is a schematic structural diagram of an optical lens 500 provided in Example 5 of the present invention. Compared with Example 1, this embodiment has the following main differences: the fifth lens L5, the sixth lens L6, and the seventh lens L7 form a cemented lens group with negative optical power; the object-side surface S9 of the fifth lens L5 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0140] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0141] Table 5-1

[0142]

[0143] The surface parameters of the aspheric lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0144] Table 5-2

[0145] Face number K B C D E F S7 1.84E+02 -2.57E-04 3.32E-06 -6.60E-07 2.78E-08 -7.34E-10 S8 -8.17E-01 3.76E-05 -3.03E-06 -3.51E-07 1.05E-08 -3.08E-10 S13 -1.14E+02 -3.09E-04 -1.08E-05 -2.15E-07 -5.27E-09 -2.37E-10 S14 1.25E+00 -7.84E-05 -7.29E-06 -9.30E-08 -5.96E-09 1.59E-12

[0146] from Figure 10 It can be seen that the MTF value of this embodiment is above 0.28 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0147] Example 6

[0148] See also Figure 11 , shown is a schematic structural diagram of an optical lens 600 provided in Example 6 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the fifth lens L5, the sixth lens L6, and the seventh lens L7 form a cemented lens group with negative optical power; the image-side surface S6 of the third lens L3 is convex; the object-side surface S9 of the fifth lens L5 is concave; and the image-side surface S14 of the seventh lens L7 is convex; and the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0149] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0150] Table 6-1

[0151]

[0152] The surface parameters of the aspheric lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0153] Table 6-2

[0154] Face number K B C D E F S7 8.97E+01 -2.86E-04 -3.56E-07 0.00E+00 0.00E+00 0.00E+00 S8 -1.70E-01 -3.37E-04 4.87E-06 -8.50E-08 1.04E-09 -1.23E-11 S13 -2.00E+02 -4.77E-04 2.09E-06 -2.77E-07 1.16E-08 -2.52E-10 S14 1.07E+01 -2.00E-04 1.65E-07 -3.16E-08 1.72E-09 -4.54E-11

[0155] from Figure 12 It can be seen that the MTF value of this embodiment is above 0.3 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0156] Example 7

[0157] See also Figure 13, shown is a schematic structural diagram of an optical lens 700 provided in Example 7 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the fifth lens L5, the sixth lens L6, and the seventh lens L7 form a cemented lens group with negative optical power; the image-side surface S6 of the third lens L3 is convex; the object-side surface S9 of the fifth lens L5 is concave; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0158] The relevant parameters of each lens in the optical lens 700 in Example 7 are shown in Table 7-1.

[0159] Table 7-1

[0160]

[0161] The surface parameters of the aspheric lens of the optical lens 700 in Example 7 are shown in Table 7-2.

[0162] Table 7-2

[0163] Face number K B C D E F S7 1.18E+02 -1.65E-04 -5.67E-07 0.00E+00 0.00E+00 0.00E+00 S8 -1.75E+00 -1.45E-04 9.95E-08 -3.25E-08 1.11E-10 -2.23E-12 S13 -1.57E+02 -3.26E-04 6.24E-06 -8.13E-07 3.22E-08 -6.29E-10 S14 2.82E+00 -8.11E-05 2.23E-06 -2.10E-07 6.74E-09 -1.15E-10

[0164] from Figure 14 It can be seen that the MTF value of this embodiment is above 0.2 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0165] Example 8

[0166] See also Figure 15 , shown is a schematic structural diagram of an optical lens 800 provided in Example 8 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image-side surface S4 of the second lens L2 is a concave surface; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0167] The relevant parameters of each lens in the optical lens 800 in Example 8 are shown in Table 8-1.

[0168] Table 8-1

[0169]

[0170] The surface parameters of the aspheric lens of the optical lens 800 in Example 8 are shown in Table 8-2.

[0171] Table 8-2

[0172] Face number K B C D E F S7 2.00E+02 -2.91E-04 -1.44E-06 2.93E-07 -1.35E-08 2.91E-10 S8 3.87E+00 2.36E-05 4.96E-06 -1.29E-07 5.15E-09 -3.75E-11 S13 1.84E+02 -1.14E-03 -4.19E-05 2.05E-06 -1.29E-07 2.72E-09 S14 1.55E+01 -6.55E-04 -1.74E-05 8.05E-07 -2.60E-08 4.72E-10

[0173] from Figure 16 It can be seen that the MTF value of this embodiment is above 0.2 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0174] Example 9

[0175] See also Figure 17 , shown is a schematic structural diagram of an optical lens 900 provided in Example 9 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S4 of the second lens element L2 is concave; the image-side surface S6 of the third lens element L3 is convex; the image-side surface S14 of the seventh lens element L7 is convex; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0176] The relevant parameters of each lens in the optical lens 900 in Example 9 are shown in Table 9-1.

[0177] Table 9-1

[0178]

[0179] The surface parameters of the aspheric lens of the optical lens 900 in Example 9 are shown in Table 9-2.

[0180] Table 9-2

[0181] Face number K B C D E F S7 -1.62E+02 -3.99E-04 3.85E-07 -1.08E-07 3.38E-09 -4.37E-11 S8 7.92E+00 -1.31E-04 8.07E-07 -6.94E-08 2.43E-09 -2.88E-11 S13 -2.22E+01 -8.46E-04 -1.59E-05 4.38E-07 -2.09E-08 2.78E-10 S14 1.30E+01 -5.33E-04 -8.29E-06 3.07E-07 -7.92E-09 8.56E-11

[0182] from Figure 18 It can be seen that the MTF value of this embodiment is above 0.25 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0183] Example 10

[0184] See also Figure 19 , shown is a schematic structural diagram of the optical lens 1000 provided in Example 10 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S4 of the second lens L2 is concave; the image-side surface S6 of the third lens L3 is convex; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0185] The relevant parameters of each lens in the optical lens 1000 in Example 10 are shown in Table 10-1.

[0186] Table 10-1

[0187]

[0188]

[0189] The surface parameters of the aspheric lens of the optical lens 1000 in Example 10 are shown in Table 10-2.

[0190] Table 10-2

[0191] Face number K B C D E F S7 -1.93E+01 -3.56E-04 9.95E-06 1.58E-09 -7.32E-10 -2.91E-12 S8 -1.16E+00 6.50E-06 6.31E-06 5.55E-08 -1.14E-09 7.74E-12 S13 -9.28E+01 -1.30E-03 -4.53E-05 2.55E-06 -1.82E-07 4.35E-09 S14 7.26E+00 -6.94E-04 -1.69E-05 8.42E-07 -2.88E-08 5.94E-10

[0192] from Figure 20 It can be seen that the MTF value of this embodiment is above 0.38 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0193] Example 11

[0194] See also Figure 21 , shown is a schematic structural diagram of an optical lens 1100 provided in Example 11 of the present invention. Compared with Example 1, this embodiment mainly differs in that: the image-side surface S4 of the second lens L2 is concave; the image-side surface S14 of the seventh lens L7 is convex; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0195] The relevant parameters of each lens in the optical lens 1100 in Example 11 are shown in Table 11-1.

[0196] Table 11-1

[0197]

[0198]

[0199] The surface parameters of the aspheric lens of the optical lens 1100 in Example 11 are shown in Table 11-2.

[0200] Table 11-2

[0201] Face number K B C D E F S7 1.99E+02 -3.61E-04 -1.10E-06 -4.09E-08 -5.26E-10 5.05E-11 S8 2.67E+00 -1.18E-04 1.28E-06 -1.61E-07 5.39E-09 -8.13E-11 S13 -2.00E+02 -1.15E-03 -1.62E-05 3.99E-07 -3.62E-08 8.84E-10 S14 6.21E+01 -7.52E-04 -3.67E-06 2.33E-07 -5.24E-09 9.11E-11

[0202] from Figure 22 It can be seen that the MTF value of this embodiment is above 0.38 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0203] Example 12

[0204] See also Figure 23 , shown is a schematic structural diagram of an optical lens 1200 provided in Example 12 of the present invention. Compared with Example 1, this embodiment has the following main differences: the image-side surface S4 of the second lens element L2 is concave; the object-side surface S5 of the third lens element L3 is concave; the image-side surface S6 of the third lens element L3 is convex; and the image-side surface S14 of the seventh lens element L7 is convex; and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0205] The relevant parameters of each lens in the optical lens 1200 in Example 12 are shown in Table 12-1.

[0206] Table 12-1

[0207]

[0208]

[0209] The surface parameters of the aspheric lens of the optical lens 1200 in Example 12 are shown in Table 12-2.

[0210] Table 12-2

[0211] Face number K B C D E F S7 -7.61E+01 -2.53E-04 9.26E-08 -4.61E-07 1.81E-08 -3.94E-10 S8 3.83E+00 7.11E-05 1.22E-06 2.06E-08 -2.35E-09 1.36E-10 S13 -5.46E+01 -7.22E-04 -5.66E-06 -4.54E-07 1.63E-08 -4.42E-10 S14 3.80E+01 -5.22E-04 -5.16E-06 1.38E-07 -1.73E-09 1.66E-12

[0212] from Figure 24 As can be seen from the figure, the MTF value of this embodiment is above 0.35 in the entire field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0213] Please refer to Table 13, which shows the optical characteristics corresponding to the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, real image height IH corresponding to the maximum field of view angle, maximum field of view angle FOV, and the numerical value corresponding to each conditional expression in each embodiment.

[0214] Table 13

[0215]

[0216]

[0217]

[0218] In summary, the optical lens provided by the present invention uses eight lenses with specific optical powers. Through the combination of specific surface shapes 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 image surface, large aperture, and high imaging quality.

[0219] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations 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 any one or more embodiments or examples.

[0220] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An optical lens, comprising eight 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 concave; A third lens with a positive optical power; A fourth lens with a positive optical power, whose object side is concave and whose image side is convex; A fifth lens with a positive optical power, whose image side is convex; A sixth lens with a negative optical power, whose object side is concave and whose image side is concave; A seventh lens with a positive optical power, whose object side is convex; An eighth lens with a positive optical power, whose object side is concave and whose image side is convex; Wherein, the curvature radius R7 of the object side of the fourth lens and the curvature radius R8 of the image side of the fourth lens satisfy: 0 < (R7 - R8) / (R7 + R8) < 0.9; the curvature radius R15 of the object side of the eighth lens and the curvature radius R16 of the image side of the eighth lens satisfy: 0.1 < (R15 - R16) / (R15 + R16) < 1.

2. The optical lens according to claim 1, wherein: The overall optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 6.1 < TTL / f < 8.5; the overall optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 2.7 < TTL / IH < 3.

6.

3. The optical lens according to claim 1, wherein: The maximum field angle FOV of the optical lens and the f-number Fno of the optical lens satisfy: 75° < FOV / Fno < 100°; 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: 3.1 < IH / EPD < 4.

3.

4. The optical lens according to claim 1, wherein: 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: 1.8 < IH / f < 2.6; the effective focal length f of the optical lens and the back focal length BFL of the optical lens satisfy: 0.64 < BFL / f < 1.

85.

5. The optical lens according to claim 1, wherein: 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: 0.4 < d1 / (IH / 2) / tan(FOV / 2) < 0.71; the combined focal length f45678 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens and the effective focal length f of the optical lens satisfy: 1.5 < f45678 / f < 5.

5.

6. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: -2.9 < f1 / f < -; the curvature radius R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: 4 < R1 / f < 14; the curvature radius R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: 1 < R2 / f < 1.

4.

7. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f2 of the second lens satisfy: -70 < f2 / f < -2.5; the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: 1.8 < f3 / f < 6.

8. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 2.8 < f4 / f < 15.8; the object-side curvature radius R7 of the fourth lens and the effective focal length f of the optical lens satisfy: -15 < R7 / f < -3.5; the image-side curvature radius R8 of the fourth lens and the effective focal length f of the optical lens satisfy: -4.5 < R8 / f < -1.

5.

9. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 1.2 < f5 / f < 3; the effective focal length f of the optical lens and the focal length f6 of the sixth lens satisfy: -1 < f6 / f < -0.7; the effective focal length f of the optical lens and the focal length f7 of the seventh lens satisfy: 1.2 < f7 / f < 2.

5.

10. The optical lens according to claim 1, wherein: The effective focal length f of the optical lens and the focal length f8 of the eighth lens satisfy: 2.7 < f8 / f < 40; the object-side curvature radius R15 of the eighth lens and the effective focal length f of the optical lens satisfy: -70 < R15 / f < -8.5; the image-side curvature radius R16 of the eighth lens and the effective focal length f of the optical lens satisfy: -16 < R16 / f < -2.1.

Images