Optical lens

Abstract

The application provides an optical lens, which has eight lenses with optical power, and sequentially comprises, along an optical axis from an object side to an imaging surface, a first lens with negative optical power; a second lens with negative optical power; a third lens with negative optical power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; a fourth lens with positive optical power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a fifth lens with positive optical power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; a sixth lens with negative optical power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface; a seventh lens with positive optical power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; and an eighth lens with negative optical power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface. The optical lens provided by the application can improve the imaging quality of the optical lens, reduce aberration, and improve the imaging quality of the optical lens.

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] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An optical lens has eight lenses with optical power, arranged sequentially along the optical axis from the object side to the imaging plane:

[0007] A first lens with negative optical power;

[0008] A second lens with negative optical power;

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

[0010] The fourth lens with positive optical power has a convex object-side surface and a convex image-side surface.

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

[0012] The sixth lens with negative optical power has a concave object side and a convex image side.

[0013] The seventh lens with positive optical power has a convex object-side surface and a convex image-side surface.

[0014] The eighth lens has a negative optical power, with both its object-side and image-side surfaces being concave.

[0015] wherein the radius of curvature R12 of the image side of the sixth lens and the effective focal length f of the optical lens satisfy: -7.8<R12 / f<-1.8; and the radius of curvature R11 of the object side of the sixth lens and the radius of curvature R12 of the image side of the sixth lens satisfy: 0<R11 / R12<0.3.

[0016] Further preferably, the light-passing half-aperture d1 of the object side of the first lens and the light-passing half-aperture d16 of the image side of the eighth lens satisfy: 1.1<d1 / d16<1.6.

[0017] Further preferably, the combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.8<f56 / f<3.3.

[0018] Further preferably, the combined focal length f48 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: 0.45<f48 / f<0.7.

[0019] Further preferably, the sagittal height SAG4 at the light-passing half-aperture of the image side of the second lens, the sagittal height SAG3 at the light-passing half-aperture of the object side of the second lens and the center thickness CT2 of the second lens satisfy: -0.2<(SAG4-SAG3) / CT2<0.28.

[0020] Further preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.9<TTL / f<2.7.

[0021] Further preferably, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -9.5<f3 / f<-5.5.

[0022] Further preferably, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -8.5<f3 / f4<-5.5.

[0023] Further preferably, the center thickness CT5 of the fifth lens and the center thickness CT6 of the sixth lens satisfy: 2<CT5 / CT6<10.

[0024] Further preferably, the radius of curvature R11 of the object side of the sixth lens and the radius of curvature R12 of the image side of the sixth lens satisfy: -0.9<(R11-R12) / (R11+R12)<-0.55.

[0025] The optical lens provided by this invention uses eight 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 large aperture, long focal length, high pixel count, and high imaging quality. Attached Figure Description

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

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

[0028] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0029] Figure 3 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0030] Figure 4 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0031] Figure 5 This is an MTF curve of the optical lens in Embodiment 1 of the present invention.

[0032] Figure 6 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0033] Figure 7 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0034] Figure 8 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0035] Figure 9 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0036] Figure 10 This is the MTF curve of the optical lens in Embodiment 2 of the present invention.

[0037] Figure 11 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0038] Figure 12 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0039] Figure 13 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0040] Figure 14 This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0041] Figure 15 This is an MTF curve of the optical lens in Embodiment 3 of the present invention.

[0042] Figure 16 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0043] Figure 17 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0044] Figure 18 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0045] Figure 19 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0046] Figure 20 This is the MTF curve of the optical lens in Embodiment 4 of the present invention.

[0047] Figure 21 This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0048] Figure 22 This is a field curvature curve diagram of the optical lens in Embodiment 5 of the present invention.

[0049] Figure 23 This is an axial aberration curve of the optical lens in Embodiment 5 of the present invention.

[0050] Figure 24 This is a chromatic aberration curve of the optical lens in Embodiment 5 of the present invention.

[0051] Figure 25 This is the MTF curve of the optical lens in Embodiment 5 of the present invention.

[0052] Figure 26 This is a schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0053] Figure 27 This is a field curvature curve diagram of the optical lens in Embodiment 6 of the present invention.

[0054] Figure 28 This is an axial aberration curve of the optical lens in Embodiment 6 of the present invention.

[0055] Figure 29 This is a chromatic aberration curve of the optical lens in Embodiment 6 of the present invention.

[0056] Figure 30 This is the MTF curve of the optical lens in Embodiment 6 of the present invention.

[0057] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] The optical lens of this embodiment of the invention has eight lenses with optical power, arranged sequentially along the optical axis from the object side to the imaging plane as follows: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens.

[0066] In some embodiments, the first lens may have negative optical power, and its object-side surface may be concave or convex, and its image-side surface may be concave or convex. The second lens may have negative optical power, and its object-side surface may be concave or convex, and its image-side surface may be concave or convex. The third lens may have negative optical power, its object-side surface is convex, and its image-side surface is concave. The fourth lens may have positive optical power, and its object-side surface is convex, and its image-side surface is convex. The fifth lens may have positive optical power, and its object-side surface is convex, and its image-side surface is convex. The sixth lens may have negative optical power, its object-side surface is concave, and its image-side surface is convex. The seventh lens may have positive optical power, its object-side surface is convex, and its image-side surface is convex. The eighth lens may have negative optical power, its object-side surface is concave, and its image-side surface is concave.

[0067] In some embodiments, the optical lens may further 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 to change the brightness of the image.

[0068] In some embodiments, the optical lens may further include a filter disposed between the eighth lens and the imaging surface. The filter is used to filter out interfering light and prevent it from reaching the imaging surface of the optical lens and affecting normal imaging.

[0069] In some embodiments, the fifth lens and the sixth lens can be cemented 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 aberrations 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.

[0070] In some embodiments, the radius of curvature R12 of the image-side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -7.8<R12 / f<-1.8; the radius of curvature R11 of the object-side surface of the sixth lens and the radius of curvature R12 of the image-side surface of the sixth lens satisfy: 0<R11 / R12<0.3. Satisfying the above ranges can make the sixth lens a meniscus lens with appropriate optical power, which is beneficial for finely correcting high-order aberrations, especially off-axis aberrations, further controlling the chief ray angle, and improving the imaging quality of the optical lens.

[0071] In some embodiments, the clear half aperture d1 of the object-side surface of the first lens and the clear half aperture d16 of the image-side surface of the eighth lens satisfy: 1.1<d1 / d16<1.6. By reasonably setting the ratio of the apertures of the first and last lenses, the lens can have a large imaging surface while having a small head size, which can better meet the balance between miniaturization and high pixel count.

[0072] In some embodiments, the combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.8<f56 / f<3.3. Satisfying the above conditions helps more light enter the cemented lens smoothly, and helps to improve illumination.

[0073] In some embodiments, the combined focal length f48 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: 0.45<f48 / f<0.7. Satisfying the above requirements, by reasonably distributing the combined optical power from the fourth lens to the eighth lens, the focal length of the optical lens is balanced, the correction capability for various aberrations at the rear end of the lens is improved, and the imaging quality of the optical lens is enhanced.

[0074] In some embodiments, the sagittal height SAG4 of the clear half aperture of the image-side surface of the second lens, the sagittal height SAG3 of the clear half aperture of the object-side surface of the second lens, and the center thickness CT2 of the second lens satisfy: -0.2<(SAG4-SAG3) / CT2<0.28. Satisfying the above conditions can limit the central depression degree of the second lens and reduce the difficulty of aberration correction for the edge field of view.

[0075] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.9<TTL / f<2.7. This can effectively limit the length of the lens, which is beneficial to realizing the miniaturization of the optical lens.

[0076] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -9.5<f3 / f<-5.5. Satisfying the above conditions can control the light path trend, provide a more reasonable light incident angle for the subsequent lenses, improve the uniformity of relative illumination, and enhance the imaging quality

[0077] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -8.5<f3 / f4<-5.5. By satisfying the above conditions and reasonably setting the focal lengths of the third and fourth lenses, the convergence of light rays can be better achieved, the distance for light rays to enter the next lens can be shortened, which is conducive to the miniaturization of the optical lens.

[0078] In some embodiments, the central thickness CT5 of the fifth lens and the central thickness CT6 of the sixth lens satisfy: 2<CT5 / CT6<10. Satisfying the above conditions can reduce the performance sensitivity of the system, while ensuring the machinability of the lenses and assembly stability, and improving the assembly yield.

[0079] In some embodiments, the curvature radius R11 of the object side of the sixth lens and the curvature radius R12 of the image side of the sixth lens satisfy: -0.9<(R11-R12) / (R11+R12)<-0.55. Satisfying the above conditions is beneficial for the sixth lens to correct coma and astigmatism of the imaging system, balance field curvature, and improve imaging quality.

[0080] In some embodiments, the combined focal length f13 of the first lens, the second lens and the third lens and the combined focal length f48 of the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens satisfy: -4<f13 / f48<-3. Satisfying the above range can reasonably distribute the focal power proportion of the lens groups before and after the aperture stop, increase the relative illumination of the lens, and improve the imaging quality of the lens.

[0081] In some embodiments, the combined focal length f13 of the first lens, the second lens and the third lens and the effective focal length f of the optical lens satisfy: -2.4<f13 / f<-1.6. Meeting the above requirements, by reasonably distributing the combined focal power of the first lens to the third lens, the deflection angle of light rays at the front end of the lens can be reduced, and the generation of various off-axis aberrations can be reduced.

[0082] In some embodiments, the sag height SAG16 of the clear half-aperture on the image side of the eighth lens, the sag height SAG15 of the clear half-aperture on the object side of the eighth lens, and the central thickness CT8 of the eighth lens satisfy: 0.5<(SAG16-SAG15) / CT8<1.25. Satisfying the above conditions, by controlling the relationship between the sag height difference between the image side and the object side of the eighth lens and the central thickness of the eighth lens, it is beneficial to correct the coma of the off-axis field of view, and is conducive to improving the imaging quality of the off-axis field of view of the optical lens.

[0083] In some embodiments, the total optical length TTL of the optical lens and the real image height IH corresponding to the maximum field of view angle of the optical lens satisfy: 2.2<TTL / IH<3.7. Satisfying the above conditions can better realize the miniaturization of the lens, and at the same time ensure that the lens has a larger image plane under the condition of the same total length, and can match an imaging chip of a larger size to achieve high-definition imaging.

[0084] In some embodiments, the maximum field of view angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 20°<FOV / Fno<34°. Satisfying the above conditions is beneficial to increasing the light intake of the lens, enabling the lens to perform high-definition imaging even in dim environments.

[0085] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 0.9<IH / EPD<1.6. Satisfying the above range enables the optical lens to have sufficient image plane brightness at the edge field of view while satisfying the large image plane, preventing the occurrence of vignetting, thereby improving the imaging quality.

[0086] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the effective focal length f of the optical lens satisfy: 0.65<IH / f<0.95. Satisfying the above conditions can achieve a larger field of view angle and imaging range, and can realize the large image plane characteristic while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0087] In some embodiments, the back focal length BFL of the optical lens and the effective focal length f of the optical lens satisfy: 0.1<BFL / f<0.25. Satisfying the above range is conducive to achieving a balance between obtaining good imaging quality and easy assembly, ensuring the imaging quality of the optical lens while avoiding interference between the lens and other components, and reducing the assembly process difficulty of the camera module.

[0088] In some embodiments, the total optical length TTL of the optical lens, the real image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 0<TTL / IH / FOV<0.1 / °. Satisfying the above range can achieve a balance between large image height, long focal length and miniaturization, and improve the imaging quality of the optical lens.

[0089] In some embodiments, the effective focal length f of the optical lens, the real image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 50°<f×FOV / IH<60°. By reasonably limiting the relationship among the focal length, field of view angle and image height of the optical lens, satisfying the above conditional expression is beneficial to realizing the balance between the field of view angle of the optical lens and large target surface imaging, and better meets the use requirement of high-image-quality shooting of the optical lens.

[0090] In some embodiments, the total optical length TTL of the optical lens and the sum ΣCT of the central thicknesses of the first lens to the eighth lens along the optical axis respectively satisfy: 0.6<ΣCT / TTL<0.75. Meeting the above conditions can effectively compress the total length of the optical lens, and is beneficial to the structural design and production process of the optical lens.

[0091] In some embodiments, the clear half-aperture D1 of the object side of the first lens, the real image height IH corresponding to the maximum field of view angle of the optical lens, and the maximum field of view angle FOV of the optical lens satisfy: 1<D1 / IH / tan(FOV / 2)<2.1. Meeting the above range can ensure the balance between the size of the optical lens, the field of view angle and the image plane.

[0092] In some embodiments, the back focal length BFL of the optical lens and the total optical length TTL of the optical lens satisfy: 0<BFL / TTL<0.1. Meeting the above range and reasonably configuring the ratio of the back focal length of the optical lens to the total optical length of the optical lens is beneficial to realizing the short back focal length of the optical lens, and is beneficial to realizing the miniaturization of the optical lens while ensuring sufficient space for the installation and focusing adjustment of optical elements.

[0093] In some embodiments, the real image height IH corresponding to the maximum field of view angle of the optical lens and the F-number Fno of the optical lens satisfy: 4mm<IH / Fno<9mm. Meeting the above conditions ensures that the optical lens has a large aperture while maintaining a large image plane, so as to achieve a balance between the large image plane and the large aperture.

[0094] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -9.5<f1 / f<-3.5. Meeting the above range can allow a wide range of light to enter the optical lens to obtain more image information, and help to control lens distortion and reduce field curvature, so as to improve the geometric accuracy of the imaging plane.

[0095] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: -8<f2 / f<-5. Meeting the above conditions, the second lens adopts a negative focal lens with weaker refractive power, which can avoid introducing excessively strong light deflection, so as to better control other aberrations (such as spherical aberration and coma).

[0096] In some embodiments, the focal length f4 of the fourth lens and the effective focal length f of the optical lens satisfy: 0.75<f4 / f<1.2. The fourth lens meeting the above conditions can balance the optical power, control the back focal offset after high and low temperature, and avoid defocusing.

[0097] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 0.65<f5 / f<0.85; the focal length f6 of the sixth lens and the effective focal length f of the optical lens satisfy: -1.1<f6 / f<-0.85. The fifth lens and the sixth lens are cemented to form a double cemented lens. The fifth lens and the sixth lens may have optical powers of opposite positive and negative signs, so that various aberrations of the optical lens are fully corrected, the resolution can be improved, and high resolution is achieved. At the same time, the use of the cemented element is beneficial to reducing the tolerance sensitivity of the lenses to tilt / decentration and the like during the assembly process, improving the resolution stability, and further enhancing the system performance.

[0098] In some embodiments, the focal length f7 of the seventh lens and the effective focal length f of the optical lens satisfy: 0.9<f7 / f<2. The seventh lens adopts positive optical power, which can further focus light, optimize imaging quality, and correct residual aberrations (such as distortion, chromatic aberration, etc.), thereby ensuring imaging clarity and color reproduction.

[0099] In some embodiments, the focal length f8 of the eighth lens and the effective focal length f of the optical lens satisfy: -0.7<f8 / f<-0.45. Satisfying the above conditions, the effective focal length of the eighth lens is relatively small, and the light diverging effect is good, which can further increase the luminous flux while ensuring high imaging quality.

[0100] In some embodiments, the focal length f6 of the sixth lens and the focal length f7 of the seventh lens satisfy: -1.1<f6 / f7<-0.5. Within the above range, by reasonably setting the focal length relationship between the sixth lens and the seventh lens, the incident angle of marginal rays can be converged, the illumination uniformity and clarity at the edge of the frame can be improved, and aberrations such as distortion can be finely corrected at the same time, so that the lens frame can obtain a high-quality, clear image without vignetting and deformation.

[0101] In some embodiments, the center thickness CT1 of the first lens and the center thickness CT2 of the second lens satisfy: 0.8<CT1 / CT2<2.6. The ratio of the thickness of the first lens on the optical axis to the thickness of the second lens on the optical axis is reasonably configured, which can be mutually regulated to maintain the miniaturization feature of the optical system.

[0102] In some embodiments, the radius of curvature R1 of the object side of the first lens and the effective focal length f of the optical lens satisfy: -0.9<R1 / f<1.2; the radius of curvature R2 of the image side of the first lens and the effective focal length f of the optical lens satisfy: -1.25<R2 / f<0.8. The first lens is a meniscus negative lens. By reasonably configuring the ratio of the radius of curvature of the object side and the image side of the first lens to the effective focal length of the optical lens, the first lens can collect as much light with a large field of view angle as possible and make the light smoothly enter the rear system, increase the luminous flux of the optical lens, and effectively expand the field of view range of the optical lens.

[0103] In some embodiments, 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: 0.7 < R7 / f < 1. Meeting the above range allows the fourth lens to have an appropriate surface profile, which is beneficial to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0104] In some embodiments, the radius of curvature R15 of the object-side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -1.9 < R15 / f < -0.9. Meeting the above conditions is beneficial to moderating the deflection degree of light passing through the lens, and can reduce aberrations well.

[0105] In some embodiments, the radius of curvature R1 of the object-side surface of the first lens and the radius of curvature R2 of the image-side surface of the first lens satisfy: -0.2 < (R1-R2) / (R1+R2) < 0.25. The surface profile of the first lens that meets the above conditions is beneficial to diverging light, obtaining a larger frame, effectively eliminating aberrations, and improving the resolution capability of the optical lens.

[0106] In some embodiments, the radius of curvature R3 of the object-side surface of the second lens and the radius of curvature R4 of the image-side surface of the second lens satisfy: -0.2 < (R3-R4) / (R3+R4) < 0.2. By making the optical system satisfy the above relational expression, it is beneficial to reasonably configure the ratio of the radius of curvature of the object-side surface of the second lens to the radius of curvature of the image-side surface of the second lens, control the shape of the second lens, comprehensively balance the spherical aberration, chromatic aberration and field curvature of the optical system, reduce the risk of ghosting, improve the resolution capability of the optical system, and at the same time, is also beneficial to reducing the processing difficulty of the second lens.

[0107] In some embodiments, the radius of curvature R14 of the image-side surface of the seventh lens and the radius of curvature R15 of the object-side surface of the eighth lens satisfy: 0.1 < (R14-R15) / (R14+R15) < 0.4. Reasonably controlling the radius of curvature of the image-side surface of the seventh lens and the radius of curvature of the object-side surface of the eighth lens can ensure that the seventh lens and the eighth lens have good machinability.

[0108] In some embodiments, the optical lens satisfies the conditional expressions: 11mm<f<17mm, 27mm<TTL<40mm, 1.4<Fno<1.9, 28°<CRA<34°, 35°<FOV<55°, 8mm<IH<12.5mm, where f denotes the effective focal length of the optical lens, TTL denotes the total optical length of the optical lens, Fno denotes the F-number of the optical lens, CRA denotes the chief ray incident angle at the maximum image height of the optical lens, FOV denotes the maximum field of view of the optical lens, and IH denotes the image height corresponding to the maximum field of view of the optical lens. Satisfying the above conditions indicates that the optical lens provided by the embodiments of the present invention at least: has telephoto characteristics, which can ensure the telephoto effect of the optical lens, enable the system to have a large magnification, and achieve good imaging quality for objects in a relatively far field of view; has a suitable field of view, which can clearly photograph long-distance targets; has a large image plane, which is adapted to a large-target-surface sensor to improve better imaging quality; has a large aperture, which further increases the light intake of the lens, and can ensure clear images even in low-light environments or at night.

[0109] In some implementations, the material of the lenses in the optical lens provided by the present invention may be glass or plastic. When the material of the lenses is plastic, the production cost can be effectively reduced. In addition, when the material of the lenses is glass, the geometric chromatic aberration of the optical system can be effectively corrected by utilizing the low dispersion characteristic of 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.

[0110] In some implementations, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, and the eighth lens may be spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the first lens and the fourth lens of the present invention adopt spherical lenses or aspherical lenses; the second lens and the eighth lens adopt aspherical lenses; the third lens, the fifth lens, the sixth lens, and the seventh lens adopt spherical lenses.

[0111] In various embodiments of the present invention, when the lenses adopt aspherical lenses, each aspherical surface shape of the optical lens satisfies the following equation:

[0112]

[0113] where z is the distance between the curved surface and the vertex of the curved surface in the optical axis direction, h is the distance from the optical axis to the curved surface, c is the curvature at the vertex of the curved surface, K is the conic coefficient, and B, C, D, E, F are the 4th-order, 6th-order, 8th-order, 10th-order, and 12th-order surface coefficients respectively.

[0114] 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 equivalent substitutions and are included within the protection scope of the present invention.

[0115] Example 1

[0116] Please see Figure 1 The figure shown is a schematic diagram 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, an eighth lens L8, and a filter G1.

[0117] Among them, the first lens L1 has negative optical power, its object side S1 is convex, and its image side S2 is concave.

[0118] The second lens L2 has negative optical power, its object side S3 is concave, and its image side S4 is convex.

[0119] The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0120] The fourth lens L4 has positive optical power, and its object side S7 is convex, and its image side S8 is convex.

[0121] The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side is convex.

[0122] The sixth lens L6 has negative optical power, its object side is concave, and its image side S11 is convex.

[0123] The fifth lens L5 and the sixth lens L6 form a cemented lens group with positive optical power, that is, the cemented surface of the image side of the fifth lens L5 and the object side of the sixth lens L6 is S10.

[0124] The seventh lens L7 has positive optical power, its object side S12 is convex, and its image side S13 is convex.

[0125] The eighth lens L8 has negative optical power, its object side S14 is concave, and its image side S15 is concave.

[0126] The object-side surface S16 and the image-side surface S17 of filter G1 are both planar.

[0127] The imaging plane S18 is a plane.

[0128] The first, third, fifth, sixth, and seventh lenses are glass spherical lenses, while the second, fourth, and eighth lenses are glass aspherical lenses.

[0129] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0130] Table 1-1

[0131]

[0132] The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0133] Table 1-2

[0134] S3 -3.28E+00 3.70E-06 5.84E-06 -3.46E-08 8.73E-10 -2.30E-11 S4 -1.09E+01 8.54E-05 8.08E-06 -1.32E-08 2.13E-09 -1.04E-11 S7 3.64E-01 2.98E-05 -3.09E-06 -3.01E-08 3.57E-09 5.29E-11 S8 2.08E+00 -1.20E-04 1.01E-06 2.73E-08 -2.61E-09 1.84E-10 S14 1.06E+01 -2.18E-03 5.73E-05 -1.95E-07 -2.94E-08 9.24E-10 S15 -1.10E+01 -1.28E-03 4.24E-05 -9.94E-07 1.15E-08 -6.32E-11

[0135] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown.

[0136] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.04 mm to 0, indicating that the optical lens can effectively correct the field curvature.

[0137] Figure 3 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 0.01 mm, indicating that the optical lens can correct axial aberration well.

[0138] Figure 4 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.546 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within -1 μm to 2 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0139] Figure 5 The 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 0.48 throughout the entire field of view. Within the range of 0–120 lp / mm, the MTF curve decreases smoothly and evenly 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.

[0140] Example 2

[0141] Please see Figure 6 The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The optical lens in this embodiment is roughly the same as that in Embodiment 1. The main difference is that the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0142] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0143] Table 2-1

[0144]

[0145] The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0146] Table 2-2

[0147] S3 -9.06E+00 8.17E-05 5.46E-06 -8.97E-08 2.07E-09 -2.13E-11 S4 -2.09E+01 1.33E-04 7.94E-06 -9.23E-08 2.37E-09 4.60E-12 S7 -1.05E-01 -4.65E-05 -2.29E-06 4.28E-09 7.18E-10 3.51E-12 S8 3.09E+00 -1.44E-04 -1.18E-06 1.11E-07 -3.95E-09 6.20E-11 S14 2.52E+01 -1.35E-03 2.23E-05 -1.72E-08 -6.85E-09 2.30E-10 S15 9.69E-01 -1.44E-03 2.40E-05 -3.28E-07 -1.21E-09 4.19E-11

[0148] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 200 are respectively as follows: Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown.

[0149] from Figure 7 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0, indicating that the optical lens can effectively correct the field curvature.

[0150] from Figure 8 As can be seen, the axial aberration offset is controlled within ±0.03mm, indicating that the optical lens can effectively correct axial aberration.

[0151] from Figure 9 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0152] from Figure 10 As can be seen, the MTF value of this embodiment is above 0.5 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, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0153] Example 3

[0154] Please see Figure 11 The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The optical lens of this embodiment is roughly the same as that of Embodiment 1. The main difference is that the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0155] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0156] Table 3-1

[0157]

[0158] The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0159] Table 3-2

[0160]

[0161]

[0162] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 300 are respectively as follows: Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown.

[0163] from Figure 12 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.04mm to 0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0164] from Figure 13 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0165] from Figure 14 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0166] from Figure 15 As can be seen, the MTF value of this embodiment is above 0.6 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.

[0167] Example 4

[0168] Please see Figure 16 The diagram shows a schematic of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The optical lens in this embodiment is generally the same as that in Embodiment 1, except that: the object-side surface S1 of the first lens L1 is concave; the image-side surface S2 of the first lens L2 is convex; the object-side surface S3 of the second lens L2 is convex; the image-side surface S4 of the second lens L2 is concave; the first lens L1 is a glass aspherical lens; the fourth lens L4 is a glass spherical lens; and the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0169] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0170] Table 4-1

[0171]

[0172]

[0173] The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0174] Table 4-2

[0175] S1 -8.35E+00 2.33E-04 8.32E-08 -5.74E-09 -1.89E-10 -2.97E-12 S2 -1.69E+01 4.73E-04 2.48E-06 1.04E-08 3.01E-09 -8.37E-11 S3 -6.18E+00 2.00E-05 5.34E-06 2.82E-07 -4.72E-09 1.54E-11 S4 -1.17E+01 1.09E-04 6.29E-06 -1.27E-07 1.07E-08 -1.36E-10 S14 6.08E+00 -2.29E-03 6.81E-05 6.62E-07 -1.05E-07 2.79E-09 S15 -2.00E+00 -2.18E-03 7.24E-05 -1.44E-06 6.01E-09 1.13E-10

[0176] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 400 are respectively as follows: Figure 17 , Figure 18 , Figure 19 , Figure 20 As shown.

[0177] from Figure 17 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0178] from Figure 18 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0179] from Figure 19As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0180] from Figure 20 As can be seen, the MTF value of this embodiment is above 0.48 throughout the entire field of view. In the range of 0 to 120 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view. It has good imaging quality and good detail resolution in both low and high frequency conditions.

[0181] Example 5

[0182] Please see Figure 21 The diagram shows a schematic of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The optical lens in this embodiment is generally the same as that in Embodiment 1, except that: the object-side surface S1 of the first lens L1 is concave; the image-side surface S2 of the first lens L2 is convex; the object-side surface S3 of the second lens L2 is convex; the image-side surface S4 of the second lens L2 is concave; the first lens L1 is a glass aspherical lens; the fourth lens L4 is a glass spherical lens; and the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0183] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0184] Table 5-1

[0185]

[0186] The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0187] Table 5-2

[0188] S1 -6.60E+00 3.39E-04 -4.00E-06 3.95E-08 -1.99E-10 -1.52E-13 S2 -2.05E+01 3.03E-04 2.38E-06 -1.10E-07 2.36E-09 -1.75E-11 S3 -2.43E+00 5.66E-06 -1.86E-06 4.98E-08 -4.09E-11 -2.75E-12 S4 -4.80E+00 -8.32E-05 3.80E-06 -1.09E-07 2.38E-09 -1.83E-11 S14 5.38E+00 -1.36E-03 6.26E-05 -1.81E-06 3.65E-08 -3.17E-10 S15 2.67E+00 -1.75E-03 5.91E-05 -1.85E-06 3.25E-08 -2.97E-10

[0189] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 500 are respectively as follows: Figure 22 , Figure 23 , Figure 24 , Figure 25 As shown.

[0190] from Figure 22 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, indicating that the optical lens can effectively correct the field curvature.

[0191] from Figure 23 As can be seen, the axial aberration offset is controlled within -0.05mm to 0.02mm, indicating that the optical lens can effectively correct axial aberration.

[0192] from Figure 24 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0193] from Figure 25 As can be seen, the MTF value of this embodiment is above 0.5 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, and it has good imaging quality and good detail resolution in both low and high frequency conditions.

[0194] Example 6

[0195] Please see Figure 26 The diagram shows a schematic of the structure of the optical lens 600 provided in Embodiment 6 of the present invention. The optical lens in this embodiment is generally the same as that in Embodiment 1, except that: the object-side surface S1 of the first lens L1 is concave; the image-side surface S2 of the first lens L2 is convex; the object-side surface S3 of the second lens L2 is convex; the image-side surface S4 of the second lens L2 is concave; the first lens L1 is a glass aspherical lens; the fourth lens L4 is a glass spherical lens; and the optical parameters such as the radius of curvature, aspherical coefficient, and thickness of each lens surface are different.

[0196] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0197] Table 6-1

[0198]

[0199]

[0200] The surface profile parameters of the aspherical lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0201] Table 6-2

[0202] S1 -8.56E+00 4.01E-04 4.05E-06 -2.03E-07 3.74E-10 1.95E-11 S2 -1.93E+01 7.91E-04 1.35E-05 -2.98E-07 3.29E-08 -1.07E-09 S3 -4.36E+00 -5.06E-05 3.43E-06 8.83E-07 1.38E-08 -1.28E-09 S4 -1.11E+01 -1.14E-04 1.64E-05 -8.42E-07 1.18E-07 -3.86E-09 S14 8.02E+00 -2.91E-03 1.50E-04 -3.47E-06 1.11E-07 6.31E-09 S15 2.34E+00 -3.39E-03 1.38E-04 -2.38E-06 -2.54E-07 1.35E-08

[0203] In this embodiment, the field curvature curve, axial aberration curve, transverse chromatic aberration curve, and MTF curve of the optical lens 600 are respectively as follows: Figure 27 , Figure 28 , Figure 29 , Figure 30 As shown.

[0204] from Figure 27 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.02mm, indicating that the optical lens can effectively correct the field curvature.

[0205] from Figure 28 As can be seen, the axial aberration offset is controlled within -0.03mm to 0.01mm, indicating that the optical lens can effectively correct axial aberration.

[0206] from Figure 29 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±1μm, indicating that the optical lens can effectively correct chromatic aberration.

[0207] from Figure 30 As can be seen, the MTF value of this embodiment is above 0.6 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.

[0208] Please refer to Table 7 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, principal ray incident angle CRA at the maximum image height, maximum field of view FOV, and the values ​​corresponding to each conditional expression in each embodiment.

[0209] Table 7

[0210]

[0211]

[0212]

[0213] In summary, the optical lens provided by the present invention employs eight 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 large aperture, long focal length, high pixel count, and high imaging quality.

[0214] 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.

[0215] 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 eight lenses having optical power, characterized in that, In sequence from the object side to the image plane along the optical axis, the system comprises: a first lens with negative optical power; a second lens with negative optical power; a third lens with negative optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface; a fourth lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; a fifth lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; a sixth lens with negative optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a convex surface; a seventh lens with positive optical power, wherein the object side surface thereof is a convex surface, and the image side surface thereof is a convex surface; an eighth lens with negative optical power, wherein the object side surface thereof is a concave surface, and the image side surface thereof is a concave surface; wherein the radius of curvature R12 of the image side surface of the sixth lens and the effective focal length f of the optical lens satisfy: -7.8<R12 / f<-1.8; the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: 0<R11 / R12<0.3; the sagittal height SAG4 of the clear aperture half-diameter of the image side surface of the second lens, the sagittal height SAG3 of the clear aperture half-diameter of the object side surface of the second lens and the center thickness CT2 of the second lens satisfy: -0.2<(SAG4-SAG3) / CT2<0.28; the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 1.9<TTL / f<2.

7.

2. The optical lens according to claim 1, characterized in that, the clear aperture half-diameter d1 of the object side surface of the first lens and the clear aperture half-diameter d16 of the image side surface of the eighth lens satisfy: 1.1<d1 / d16<1.

6.

3. The optical lens according to claim 1, characterized in that, the combined focal length f56 of the fifth lens and the sixth lens and the effective focal length f of the optical lens satisfy: 1.8<f56 / f<3.

3.

4. The optical lens according to claim 1, characterized in that, the combined focal length f48 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: 0.45<f48 / f<0.

7.

5. The optical lens according to claim 1, characterized in that, 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: 0.7<R7 / f<1.

6. The optical lens according to claim 1, characterized in that, the radius of curvature R15 of the object side surface of the eighth lens and the effective focal length f of the optical lens satisfy: -1.9<R15 / f<-0.

9.

7. The optical lens according to claim 1, characterized in that, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -9.5<f3 / f<-5.

5.

8. The optical lens according to claim 1, characterized in that, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -8.5<f3 / f4<-5.

5.

9. The optical lens according to claim 1, characterized in that, the center thickness CT5 of the fifth lens and the center thickness CT6 of the sixth lens satisfy: 2<CT5 / CT6<10.

10. The optical lens according to claim 1, characterized in that, the radius of curvature R11 of the object side surface of the sixth lens and the radius of curvature R12 of the image side surface of the sixth lens satisfy: -0.9<(R11-R12) / (R11+R12)<-0.55.

Images