Optical lens

Abstract

The invention discloses an optical lens, and the optical lens sequentially comprises a first lens with negative focal power, a second lens with positive focal power or negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, and a fifth lens with positive focal power from the object side to the image side along an optical axis. The first lens has a positive focal power, the second lens has a negative focal power, the sixth lens has a negative focal power, the seventh lens has a positive focal power, the eighth lens has a negative focal power, and the ninth lens has a positive focal power. Wherein the effective focal length F3 of the third lens and the total effective focal length F of the optical lens meet the condition that F3 / F is larger than or equal to 0.7 and smaller than or equal to 1.2.

Description

Technical Field

[0001] The present application relates to the field of optical elements, and more specifically, to an optical lens. Background Art

[0002] With the continuous upgrading and development of Internet technology, video lenses are widely used in video conferencing, online teaching, live streaming and other shooting fields, so the requirements for their image quality are getting higher and higher.

[0003] However, existing video lenses still have many shortcomings. For example, some existing lenses are generally too long and too large in size, which makes the overall cost and weight of the lenses too high; the thermal stability of the lenses is poor and cannot meet the requirements of clear imaging in extreme temperature environments; in addition, some existing lens systems have large aberrations, poor imaging quality, and large distortion, which causes obvious deformation of the captured images and affects the later image processing; and some existing lenses have small imaging circles and cannot meet the imaging requirements of large target chips with higher resolution. Summary of the invention

[0004] The present application provides an optical lens, which may include, in order from the object side to the image side along the optical axis: a first lens with negative optical power, a second lens with positive optical power or negative optical power, a third lens with positive optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, a sixth lens with negative optical power, a seventh lens with positive optical power, an eighth lens with negative optical power, and a ninth lens with positive optical power; wherein an effective focal length F3 of the third lens and a total effective focal length F of the optical lens may satisfy: 0.7≤F3 / F≤1.2.

[0005] In one embodiment, the object side surface of the second lens is concave, and the image side surface is convex; the object side surface of the third lens is convex, and the image side surface is concave; the object side surface of the fourth lens is convex, and the image side surface is concave; the image side surface of the fifth lens is convex, and the image side surface is convex; the object side surface of the sixth lens is convex, and the image side surface is concave; the object side surface of the seventh lens is convex, and the image side surface is convex; the object side surface of the eighth lens is convex, and the image side surface is concave; the object side surface of the ninth lens is convex, and the image side surface is concave.

[0006] In one embodiment, the fourth lens and the fifth lens are doublet lenses cemented to each other.

[0007] In one embodiment, the effective focal length F1 of the first lens and the total effective focal length F of the optical lens may satisfy: -1.6≤F1 / F≤-1.14.

[0008] In one embodiment, the radius of curvature R21 of the object-side surface of the second lens and the total effective focal length F of the optical lens may satisfy: -1.1≤R21 / F≤-0.5.

[0009] In one embodiment, the effective focal length F4 of the fourth lens and the total effective focal length F of the optical lens may satisfy: -0.9≤F4 / F≤-0.4.

[0010] In one embodiment, the effective focal length F5 of the fifth lens and the total effective focal length F of the optical lens may satisfy: 0.4≤F5 / F≤0.8.

[0011] In one embodiment, the effective focal length F6 of the sixth lens and the total effective focal length F of the optical lens may satisfy: -2.33≤F6 / F≤-1.7.

[0012] In one embodiment, the effective focal length F7 of the seventh lens and the total effective focal length F of the optical lens may satisfy: 0.41≤F7 / F≤8.69.

[0013] In one embodiment, the effective focal length F8 of the eighth lens and the total effective focal length F of the optical lens may satisfy: -3.84≤F8 / F≤-1.73.

[0014] In one embodiment, a curvature radius R91 of the object-side surface of the ninth lens and a curvature radius R92 of the image-side surface of the ninth lens may satisfy: 0.4≤R91 / R92≤0.8.

[0015] In one embodiment, the effective focal length F9 of the ninth lens and the total effective focal length F of the optical lens may satisfy: 1.1≤F9 / F≤1.8.

[0016] In one embodiment, the combined effective focal length F45 of the fourth lens and the fifth lens and the total effective focal length F of the optical lens may satisfy: 0≤F45 / F≤60.15.

[0017] In one embodiment, the combined effective focal length Fb of the fourth to ninth lenses and the total effective focal length F of the optical lens may satisfy: 2.71≤Fb / F≤7.42.

[0018] In one embodiment, the refractive index ND3 of the third lens may satisfy: 1.85≤ND3≤2.01.

[0019] In one embodiment, the Abbe number VD5 of the fifth lens may satisfy: 60≤VD5≤95.

[0020] In one embodiment, the total effective focal length F of the optical lens and the entrance pupil diameter ENPD of the optical lens may satisfy: 2.1≤F / ENPD≤2.3.

[0021] In one embodiment, the maximum light-clearance full aperture Dmax of the optical lens and the distance TTL from the center of the object-side surface of the first lens to the imaging surface of the optical lens on the optical axis may satisfy: 0.3≤Dmax / TTL≤0.5.

[0022] In one embodiment, a distance BFL from the center of the image side surface of the ninth lens to the imaging plane on the optical axis and a distance TTL from the center of the object side surface of the first lens to the imaging plane on the optical axis may satisfy: 0.04≤BFL / TTL≤0.2.

[0023] In one embodiment, the optical lens may satisfy at least one of the following conditions: -1.55≤F1 / F≤-1.16; -1.06≤R21 / F≤-0.58; -0.75≤F4 / F≤-0.54; 0.55≤F5 / F≤0.68; -2.28≤F6 / F≤-1.80; 1.74≤F7 / F≤7.36; -3.54≤F8 / F≤-2.03; 0.55≤R91 / R92≤0.71; wherein F1 is the effective focal length of the first lens, R21 is the radius of curvature of the object side surface of the second lens, F4 is the effective focal length of the fourth lens, F5 is the effective focal length of the fifth lens, F6 is the effective focal length of the sixth lens, F7 is the effective focal length of the seventh lens, F8 is the effective focal length of the eighth lens, R91 is the radius of curvature of the object side surface of the ninth lens, and R92 is the radius of curvature of the image side surface of the ninth lens.

[0024] The optical lens according to the embodiment of the present application includes first to ninth lenses arranged in sequence from the object side to the image side along the optical axis, wherein the first, fourth, sixth and eighth lenses all have negative optical focal lengths, the third, fifth, seventh and ninth lenses all have positive optical focal lengths, and the second lens may have positive or negative optical focal lengths; the effective focal length F3 of the third lens and the total effective focal length F of the lens satisfy the conditional formula 0.7≤F3 / F≤1.2. By means of the above-mentioned setting of the optical lens, the focal length value of the third lens is reasonably allocated, and it can be matched with a high refractive index material, so as to correct the spherical aberration generated by the previous optical system, which is conducive to achieving high image quality.

[0025] According to the embodiment of the present application, the high-definition large-target optical lens adopts a nine-piece structure. By reasonably setting some parameters of the lens such as the focal length, surface shape, radius of curvature, refractive index and Abbe number, the lens can have some or all of the characteristics such as short optical total length, good thermal stability, high resolution, low distortion, high illumination and large target surface. For example, the optical lens can clearly and stably image at an ambient temperature of -30℃ to 70℃, and the optical distortion can meet: |Optical Distortion|≤2.1%, and the target surface size of the lens can meet or exceed 1 / 1.55 ​​inches. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, purposes and advantages of the present application will become more apparent through the following detailed description of the embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0027] Figure 1 A schematic structural diagram of an optical lens according to Embodiment 1 of the present application is shown;

[0028] Figure 2 shows a distortion curve diagram of the optical lens according to Example 1 of the present application;

[0029] Figure 3 shows a relative illumination curve diagram of the optical lens according to Example 1 of the present application;

[0030] Figure 4 A schematic structural diagram of an optical lens according to Embodiment 2 of the present application is shown;

[0031] Figure 5 shows a distortion curve diagram of the optical lens according to Example 2 of the present application;

[0032] Figure 6 shows a relative illumination curve diagram of the optical lens according to Example 2 of the present application;

[0033] Figure 7 A schematic structural diagram of an optical lens according to Embodiment 3 of the present application is shown;

[0034] Figure 8 shows a distortion curve diagram of the optical lens according to Example 3 of the present application;

[0035] Fig. 9 shows a relative illumination curve diagram of the optical lens according to Example 3 of the present application;

[0036] Fig.10 A schematic structural diagram of an optical lens according to Embodiment 4 of the present application is shown;

[0037] Fig.11 shows a distortion curve diagram of the optical lens according to Example 4 of the present application;

[0038] Fig.12 A relative illumination curve diagram of the optical lens according to Example 4 of the present application is shown. DETAILED DESCRIPTION

[0039] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same figure numbers refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

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

[0042] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object side of the lens, and the surface of each lens closest to the imaging side is called the image side of the lens.

[0043] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] The features, principles and other aspects of the present application are described in detail below.

[0047] In an exemplary embodiment, the optical lens according to the present application may include, for example, nine lenses having optical power, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens. The nine lenses may be arranged in sequence from the object side to the image side along the optical axis.

[0048] In an exemplary embodiment, the first lens may have negative optical power; the second lens may have positive optical power or negative optical power; the third lens may have positive optical power; the fourth lens may have negative optical power; the fifth lens may have positive optical power; the sixth lens may have negative optical power; the seventh lens may have positive optical power; the eighth lens may have negative optical power; and the ninth lens may have positive optical power.

[0049] In an exemplary embodiment, the first lens may have a negative optical power. The object side surface of the first lens may be a convex surface, and the image side surface may be a concave surface. By setting the first lens in this way, it is possible to facilitate the collection of light in the optical system, and effectively increase the field of view and illumination.

[0050] In an exemplary embodiment, the second lens may have positive power or negative power. The object side surface of the second lens may be concave, and the image side surface may be convex. By setting the second lens in this way, the trend of the edge field light can be effectively controlled to avoid the generation of high-order aberrations; at the same time, it is beneficial to balance the field curvature of the optical system and improve the imaging quality of the optical system.

[0051] In an exemplary embodiment, the third lens may have positive focal power. The object side of the third lens may be convex, and the image side may be concave. This arrangement of the third lens is conducive to reducing the incident angle of the axial light on the object side of the third lens, reducing the spherical aberration generated by the object side of the third lens, and thus facilitating high image quality. Optionally, the third lens may be made of a material with a larger refractive index, reducing the surface curvature, reducing the generation of aberrations, and facilitating high image quality.

[0052] In an exemplary embodiment, the fourth lens may have negative power. The object side of the fourth lens may be convex, and the image side may be concave. The fourth lens bears a larger optical power of the system, which is beneficial to balancing the spherical aberration, coma and astigmatism of the optical system, and improving the imaging quality of the optical system; the fourth lens has negative power in the double-cemented lens, and cooperates with the fifth lens to achieve achromatism, which is beneficial to achieve high image quality and reduce the sensitivity of system tolerance.

[0053] In an exemplary embodiment, the fifth lens may have positive power. The object side of the fifth lens may be convex, and the image side may be convex. The fifth lens shares the power, reduces the surface curvature, reduces the generation of aberrations, and is conducive to achieving high image quality. The fifth lens has positive power in the double-cemented lens, and can be preferably matched with low-dispersion materials to achromatize the system. It also helps to suppress the focus drift of the lens in high and low temperature environments, and achieves high imaging quality in a large temperature range (for example, -30°C to 70°C).

[0054] In an exemplary embodiment, the sixth lens may have a negative optical power. The object side surface of the sixth lens may be a convex surface, and the image side surface may be a concave surface. By setting the sixth lens in this way, the incident angle of the axial light on the image side surface of the sixth lens can be reduced, and the spherical aberration generated by the image side surface of the sixth lens can be reduced; at the same time, the trend of the off-axis light can be effectively controlled, so that the light can smoothly transition to the rear of the optical system, thereby reducing the generation of coma and astigmatism, which is conducive to achieving high image quality.

[0055] In an exemplary embodiment, the seventh lens may have positive power. The object side surface of the seventh lens may be convex, and the image side surface may be convex. By setting the seventh lens in this way, the incident angle of the axial light on the image side surface of the seventh lens can be reduced, and the spherical aberration generated on the image side surface of the seventh lens can be reduced, which is conducive to achieving high image quality; at the same time, the trend of the light can be effectively controlled, so that the light can smoothly transition to the rear of the optical system, and the edge field light can be raised to allow it to smoothly enter the image surface, which is conducive to achieving large target surface imaging.

[0056] In an exemplary embodiment, the eighth lens may have a negative optical power. The object side of the eighth lens may be a convex surface, and the image side may be a concave surface. By setting the eighth lens in this way, the incident angle of off-axis light on the image side of the eighth lens can be reduced, thereby reducing the generation of coma and astigmatism, which is conducive to achieving high image quality; at the same time, the eighth lens can be designed as an aspherical surface, which can effectively correct the distortion of the system, which is conducive to achieving low-distortion imaging.

[0057] In an exemplary embodiment, the ninth lens may have positive power. The object side of the ninth lens may be convex, and the image side may be concave. This arrangement of the ninth lens is conducive to correcting residual astigmatism, coma, and field curvature of the system, greatly improving the imaging performance of the optical system, and effectively correcting optical distortion. The last lens has positive power, which is conducive to reducing the main ray angle to match the imaging requirements of the chip.

[0058] In an exemplary embodiment, the optical lens according to the present application may include at least one aperture. The aperture may constrain the light path and control the light intensity. The aperture may be set at an appropriate position of the optical lens, for example, the aperture may be located between the third lens and the fourth lens. It should be noted that the position of the aperture disclosed herein is only an example and not a limitation; in alternative embodiments, the aperture may also be set at other positions according to actual needs.

[0059] In an exemplary embodiment, the optical lens may further include a photosensitive element disposed on the imaging surface. Optionally, the photosensitive element disposed on the imaging surface may be, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0060] In an exemplary embodiment, the optical lens may include one or more aspherical lenses. Aspherical lenses have better curvature radius characteristics, and have the advantages of improving distortion aberration and improving astigmatism aberration; after using aspherical lenses, aberrations occurring during imaging can be eliminated as much as possible, thereby improving imaging quality. For example, in some embodiments, the second lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens of the optical lens may be aspherical lenses.

[0061] In an exemplary embodiment, one or more lenses in the optical lens may have an inflection point, and the inflection may be arranged to facilitate correction of aberrations.

[0062] In an exemplary embodiment, the first lens to the ninth lens in the optical lens may be made of a glass-plastic hybrid material. The use of a glass-plastic hybrid material for each lens in the lens can help reduce the cost of the optical system, and help balance the high and low temperature performance of the optical lens, so that the lens can achieve high imaging quality in the range of, for example, -30°C to 70°C. In some other exemplary embodiments, the first lens to the ninth lens in the optical lens may all be glass lenses. An optical lens made of glass can suppress the deviation of the back focus of the optical lens with temperature changes, which is beneficial to improving the stability of the system; at the same time, it is beneficial for the lens to have high imaging quality in high and low temperature environments. In other exemplary embodiments, the first lens to the ninth lens in the optical lens may all be plastic lenses. In applications where, for example, temperature stability requirements are low, the use of plastic lenses can effectively reduce production costs.

[0063] In an exemplary embodiment, the fourth lens and the fifth lens may be double-cemented lenses that are cemented to each other. The cemented lens is conducive to balancing various aberrations, improving resolution, and achieving high resolution; at the same time, it can reduce the tolerance sensitivity between lenses, which is conducive to ensuring production yield; and it can reduce the light energy loss caused by reflection between lenses, which is conducive to improving relative illumination.

[0064] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.7≤F3 / F≤1.2, where F3 is the effective focal length of the third lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the third lens to the total effective focal length of the optical lens within this range, the focal length value of the third lens is reasonably allocated, and a high refractive index material can be used to correct the spherical aberration generated by the previous optical system, which is conducive to achieving high image quality.

[0065] In an exemplary embodiment, the optical lens according to the present application may satisfy: -1.6≤F1 / F≤-1.14, wherein F1 is the effective focal length of the first lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the first lens to the total effective focal length of the optical lens within this range, the focal length value of the first lens is reasonably allocated, and light is collected through the first lens, which is conducive to the optical system converging more incident light of the field of view, increasing the field of view angle of the optical system, and improving the lens illumination. More specifically, F1 and F may further satisfy: -1.55≤F1 / F≤-1.16.

[0066] In an exemplary embodiment, the optical lens according to the present application may satisfy: -1.1≤R21 / F≤-0.5, wherein R21 is the radius of curvature of the object side of the second lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the radius of curvature of the object side of the second lens to the total effective focal length of the optical lens within this range, it is possible to effectively avoid the generation of high-order aberrations, balance the field curvature of the optical system, and achieve high image quality. More specifically, R21 and F may further satisfy: -1.06≤R21 / F≤-0.58.

[0067] In an exemplary embodiment, the optical lens according to the present application may satisfy: -0.9≤F4 / F≤-0.4, wherein F4 is the effective focal length of the fourth lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the fourth lens to the total effective focal length of the optical lens within this range, the focal length value of the fourth lens is reasonably allocated, so that the fourth lens has a negative focal power in the double-cemented lens, and cooperates with the fifth lens to achieve achromatism, which is conducive to achieving high image quality. More specifically, F4 and F may further satisfy: -0.75≤F4 / F≤-0.54.

[0068] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.4≤F5 / F≤0.8, where F5 is the effective focal length of the fifth lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the fifth lens to the total effective focal length of the optical lens within this range, the focal length value of the fifth lens is reasonably allocated, so that the fifth lens has positive focal power in the double-cemented lens, and can be matched with low-dispersion materials to achromatize the system, which is conducive to achieving high image quality. More specifically, F5 and F may further satisfy: 0.55≤F5 / F≤0.68.

[0069] In an exemplary embodiment, the optical lens according to the present application may satisfy: -2.33≤F6 / F≤-1.7, wherein F6 is the effective focal length of the sixth lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the sixth lens to the total effective focal length of the optical lens within this range, the focal length value of the sixth lens is reasonably allocated to balance the spherical aberration of the optical system, which is conducive to achieving high image quality. More specifically, F6 and F may further satisfy: -2.28≤F6 / F≤-1.80.

[0070] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.41≤F7 / F≤8.69, wherein F7 is the effective focal length of the seventh lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the seventh lens to the total effective focal length of the optical lens within this range and reasonably allocating the focal length value of the seventh lens, the angle of the light can be effectively controlled, which is conducive to achieving large target surface imaging. More specifically, F7 and F may further satisfy: 1.74≤F7 / F≤7.36.

[0071] In an exemplary embodiment, the optical lens according to the present application may satisfy: -3.84≤F8 / F≤-1.73, wherein F8 is the effective focal length of the eighth lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the eighth lens to the total effective focal length of the optical lens within this range, the focal length value of the eighth lens is reasonably allocated to balance the coma and astigmatism of the optical system, which is conducive to achieving high image quality; it is also conducive to achieving low distortion imaging. More specifically, F8 and F may further satisfy: -3.54≤F8 / F≤-2.03.

[0072] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.4≤R91 / R92≤0.8, wherein R91 is the radius of curvature of the object side surface of the ninth lens, and R92 is the radius of curvature of the image side surface of the ninth lens. By controlling the ratio of the radius of curvature of the object side surface of the ninth lens to the radius of curvature of the image side surface within this range, it is beneficial to smooth the incident light and reduce the risk of strong energy ghost images caused by off-axis edge light. More specifically, R91 and R92 may further satisfy: 0.55≤R91 / R92≤0.71.

[0073] In an exemplary embodiment, the optical lens according to the present application may satisfy: 1.1≤F9 / F≤1.8, where F9 is the effective focal length of the ninth lens and F is the total effective focal length of the optical lens. By controlling the ratio of the effective focal length of the ninth lens to the total effective focal length of the optical lens within this range, the focal length value of the ninth lens is reasonably allocated so that the residual aberration of the system can be corrected, which is conducive to achieving high image quality; it is also conducive to achieving low distortion imaging.

[0074] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0≤F45 / F≤60.15, wherein F45 is the combined effective focal length of the fourth lens and the fifth lens, and F is the total effective focal length of the optical lens. By controlling the ratio of the combined effective focal length of the fourth lens and the fifth lens to the total effective focal length of the optical lens within this range, the focal length values ​​of the double-cemented lens are reasonably allocated, so that the combined lens compensates for the axial chromatic aberration generated by the front lens group (the first lens to the third lens), which is conducive to achieving high image quality; it is also conducive to reducing the system assembly tolerance.

[0075] In an exemplary embodiment, the optical lens according to the present application may satisfy: 2.71≤Fb / F≤7.42, wherein Fb is the combined effective focal length of the rear lens group (the fourth lens to the ninth lens), and F is the total effective focal length of the optical lens. By controlling the ratio of the combined effective focal length of the fourth lens to the ninth lens to the total effective focal length of the optical lens within this range, the combined focal length values ​​of the fourth lens to the ninth lens are reasonably allocated, so that each field of view light smoothly transitions to the rear of the optical system, which is conducive to achieving large target surface imaging; at the same time, spherical aberration, astigmatism and coma can be effectively balanced, which is conducive to achieving high image quality.

[0076] In an exemplary embodiment, the optical lens according to the present application may satisfy: 1.85≤ND3≤2.01, where ND3 is the refractive index of the third lens. By properly setting the refractive index of the third lens, the third lens may preferably be made of a material with a larger refractive index, reduce the surface curvature, reduce the generation of aberrations, and facilitate the realization of high image quality.

[0077] In an exemplary embodiment, the optical lens according to the present application may satisfy: 60≤VD5≤95, where VD5 is the Abbe number of the fifth lens. By reasonably setting the Abbe number of the fifth lens, the fifth lens may preferably be made of a material with a larger Abbe number, which is beneficial to the correction of chromatic aberration and high and low temperatures, and is beneficial to achieving a lens without out-of-focus in the temperature range of -30°C to 70°C.

[0078] In an exemplary embodiment, the optical lens according to the present application may satisfy: 2.1≤F / ENPD≤2.3, where F is the total effective focal length of the optical lens, and ENPD is the entrance pupil diameter of the optical lens. By controlling the ratio of the total effective focal length of the optical lens to the entrance pupil diameter of the optical lens within this range, the system has a smaller aperture value, which is conducive to achieving a large aperture.

[0079] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.3≤Dmax / TTL≤0.5, wherein Dmax is the maximum clear aperture of the optical lens, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the optical lens on the optical axis, that is, the total optical length of the lens. By controlling the ratio of the maximum clear aperture of the optical lens to the total optical length of the lens within this range, under a certain total optical length of the system, by controlling the maximum clear aperture of the system, the maximum clear aperture of the system is made smaller, which is conducive to miniaturization.

[0080] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.04≤BFL / TTL≤0.2, wherein BFL is the distance from the center of the image side surface of the ninth lens to the imaging surface of the optical lens on the optical axis, i.e., the system optical back focus, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the optical lens on the optical axis, i.e., the total optical length of the lens. By controlling the ratio of the system optical back focus to the system optical length within this range, the system optical back focus length can be reasonably controlled on the basis of miniaturization, thereby improving the ease of assembly of the lens and also helping to reserve space for the installation of optical elements.

[0081] In an exemplary embodiment, the optical lens of the present application may further include a filter and / or a protective glass disposed between the ninth lens and the imaging surface as required. The filter may filter light having a specific wavelength, and the protective glass may prevent the image side element (e.g., chip) of the optical lens from being damaged.

[0082] On the one hand, the optical lens provided according to the exemplary embodiment of the present application includes the first to ninth lenses arranged in sequence from the object side to the image side along the optical axis, wherein the first, fourth, sixth and eighth lenses all have negative optical focal lengths, the third, fifth, seventh and ninth lenses all have positive optical focal lengths, and the second lens may have positive or negative optical focal lengths; the effective focal length F3 of the third lens and the total effective focal length F of the lens satisfy the conditional formula 0.7≤F3 / F≤1.2. By the above-mentioned setting of the optical lens, the focal length value of the third lens is reasonably allocated, and with a high refractive index material, the spherical aberration generated by the previous optical system can be corrected, which is conducive to achieving high image quality; at the same time, it is conducive to the lens having one or more characteristics such as a short total optical length, good thermal stability, high resolution, low distortion, high illumination and a large target surface.

[0083] On the other hand, the optical lens provided according to the exemplary embodiment of the present application includes the first to ninth lenses arranged in sequence from the object side to the image side along the optical axis, wherein the first, fourth, sixth and eighth lenses all have negative optical power, the third, fifth, seventh and ninth lenses all have positive optical power, and the second lens may have positive or negative optical power; the combined effective focal length Fb of the rear lens group (the fourth lens to the ninth lens) and the total effective focal length F of the lens satisfy the conditional formula 2.71≤Fb / F≤7.42. Through the above-mentioned setting of the optical lens, the combined focal length value of the fourth lens to the ninth lens is reasonably allocated, so that each field of view light smoothly transitions to the rear of the optical system, which is conducive to the realization of large target surface imaging; at the same time, spherical aberration, astigmatism and coma can be effectively balanced, which is conducive to the realization of high image quality; at the same time, it is conducive to the lens having one or more characteristics such as short total optical length, good thermal stability, high resolution, low distortion and high illumination.

[0084] On the other hand, the optical lens provided according to the exemplary embodiment of the present application includes the first to ninth lenses arranged in sequence from the object side to the image side along the optical axis, wherein the first, fourth, sixth and eighth lenses all have negative optical power, the third, fifth, seventh and ninth lenses all have positive optical power, and the second lens may have positive or negative optical power; the effective focal length F8 of the eighth lens and the total effective focal length F of the optical lens satisfy the conditional formula -3.84≤F8 / F≤-1.73. Through the above-mentioned setting of the optical lens, the focal length value of the eighth lens is reasonably allocated to balance the coma and astigmatism of the optical system, which is conducive to achieving high image quality and low distortion imaging; at the same time, it is conducive to the lens having one or more characteristics such as short total optical length, good thermal stability, high resolution, high illumination and large target surface.

[0085] The optical lens according to the embodiment of the present application may use multiple lenses, such as the nine lenses described above. By reasonably setting some parameters of the lens parameters such as the focal length, surface shape, radius of curvature, refractive index and Abbe number, the lens can have some or all of the characteristics such as short total optical length, good thermal stability, high resolution, low distortion, high illumination and large target surface. For example, the full field illumination of the optical lens can meet ≥60%; the optical lens can form clear and stable images at an ambient temperature of -30℃ to 70℃; when the half field of view H=5.5mm, the optical distortion of the lens can meet: |OpticalDistortion|≤2.1%; the incident angle CRA of the main light of the lens can meet: CRA<13°; the target surface size of the lens can meet ≥1 / 1.55"; and the lens can meet the resolution requirements of more than 1200W, etc.

[0086] However, it should be understood by those skilled in the art that, without departing from the technical solution claimed in the present application, the number of lenses constituting the lens can be changed to obtain the various results and advantages described in this specification. For example, although ten lenses are described as an example in the embodiments, the optical lens is not limited to including ten lenses. If necessary, the optical lens may also include other numbers of lenses. The specific embodiments of the optical lens applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings.

[0087] Example 1

[0088] Figure 1 is a schematic diagram of the structure of an optical lens according to Example 1 of the present application, and the following reference is made to Figure 1 An optical lens according to Example 1 of the present application is described.

[0089] like Figure 1 As shown, the optical lens includes, from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, an aperture STO, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a filter and / or a protective glass C, and an imaging surface (IMA). The fourth lens L4 and the fifth lens L5 are doublet lenses.

[0090] In this embodiment, the first lens L1 has negative power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens L2 has positive power, its object side surface S3 is concave, and its image side surface S4 is convex. The third lens L3 has positive power, its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens L4 has negative power, its object side surface S8 is convex, and its image side surface S9 is concave. The fifth lens L5 has positive power, its object side surface S9 is convex, and its image side surface S10 is convex. The sixth lens L6 has negative power, its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens L7 has positive power, its object side surface S13 is convex, and its image side surface S14 is convex. The eighth lens L8 has negative power, its object side surface S15 is convex, and its image side surface S16 is concave. The ninth lens L9 has positive refractive power, and its object-side surface S17 is convex, and its image-side surface S18 is concave.

[0091] In this embodiment, the second lens L2, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are aspherical lenses. The aperture STO of the optical lens is located between the third lens L3 and the fourth lens L4. The distortion of the optical lens of this embodiment is -1.12%; the half field angle is 28.042°; and the half image height is 5.50 mm.

[0092] In this embodiment, the filter and / or protective glass C between the ninth lens L9 and the imaging surface has an object side surface S19 and an image side surface S20. Light from the object may, for example, sequentially pass through the surfaces S1 to S20 and finally be imaged on the imaging surface IMA, where, for example, an image sensor chip may be disposed at the imaging surface.

[0093] Table 1 shows the curvature radius R, thickness d, refractive index ND, and Abbe number VD of each lens of the optical lens of Example 1.

[0094]

[0095]

[0096] Table 1

[0097] In this embodiment, the object side surface and the image side surface of the second lens L2, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are all aspherical surfaces, and the surface shape of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0098]

[0099] in, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 below gives the cone coefficient k and the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A71, A72, A73, A74, A75 10 , A 12 , A 14 and A 16 .

[0100] Face number k A4 A6 A8 A10 A12 A14 A16 S3 0.574 3.39E-04 -6.65E-06 3.79E-06 -4.91E-07 3.56E-08 -1.36E-09 2.25E-11 S4 0.032 1.95E-04 -4.68E-06 1.00E-06 6.99E-09 -1.18E-08 8.77E-10 -1.98E-11 S11 3.231 -3.18E-03 6.85E-05 -6.92E-06 9.74E-07 -1.79E-07 1.67E-08 -6.78E-10 S12 0.655 -5.22E-03 6.68E-05 -2.05E-06 -1.17E-06 1.07E-07 -6.18E-09 -9.71E-11 S13 7.572 -1.65E-03 -1.40E-04 2.04E-05 -2.45E-06 1.71E-07 -4.25E-09 -3.57E-11 S14 -61.753 -2.92E-03 -8.17E-05 1.19E-05 -7.73E-07 1.34E-08 1.19E-09 -5.35E-11 S15 -14.401 5.48E-04 -3.45E-04 1.54E-05 -4.85E-07 1.60E-08 -5.88E-10 9.73E-12 S16 -9.035 -9.26E-04 -9.90E-05 -3.52E-06 4.80E-07 -2.19E-08 5.35E-10 -4.87E-12 S17 -5.782 -3.30E-03 5.11E-06 6.50E-06 -4.76E-07 2.16E-09 6.88E-10 -1.55E-11 S18 -8.781 -3.00E-03 2.44E-05 4.09E-06 -1.83E-07 -2.49E-10 1.43E-10 -2.35E-12

[0101] Table 2

[0102] Figure 2 shows a distortion curve diagram of the optical lens according to Example 1 of the present application, Figure 3 According to this application

[0103] The relative illumination curve of the optical lens of Example 1 is as follows: Figure 2 and Figure 3 It can be seen that the optical lens according to Example 1 of the present application has the characteristics of low distortion and high illumination, and can achieve good imaging quality.

[0104] Example 2

[0105] Figure 4 The structure diagram of the optical lens according to the second embodiment of the present application is shown below. Figure 4 The optical lens according to Embodiment 2 of the present application is described. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted.

[0106] like Figure 4 As shown, the optical lens includes, from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, an aperture STO, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a filter and / or a protective glass C, and an imaging surface (IMA). The fourth lens L4 and the fifth lens L5 are doublet lenses.

[0107] In this embodiment, the first lens L1 has negative power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens L2 has negative power, its object side surface S3 is concave, and its image side surface S4 is convex. The third lens L3 has positive power, its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens L4 has negative power, its object side surface S8 is convex, and its image side surface S9 is concave. The fifth lens L5 has positive power, its object side surface S9 is convex, and its image side surface S10 is convex. The sixth lens L6 has negative power, its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens L7 has positive power, its object side surface S13 is convex, and its image side surface S14 is convex. The eighth lens L8 has negative power, its object side surface S15 is convex, and its image side surface S16 is concave. The ninth lens L9 has positive refractive power, and its object-side surface S17 is convex, and its image-side surface S18 is concave.

[0108] The distortion of the optical lens of this embodiment is -1.17%; the half field angle is 27.805°; and the half image height is 5.50 mm.

[0109] Table 3 shows the curvature radius R, thickness d, refractive index ND, and Abbe number VD of each lens of the optical lens of Example 2.

[0110]

[0111]

[0112] Table 3

[0113] In this embodiment, the object side surface and the image side surface of the second lens L2, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are all aspherical surfaces, and the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. Table 4 shows the cone coefficient k and the high-order coefficients A4, A6, A8, A9 that can be used for each aspherical mirror surface S3-S4, S11-S18 in this embodiment. 10 , A 12 , A 14 and A 16 .

[0114] Face number k A4 A6 A8 A10 A12 A14 A16 S3 0.233 6.31E-04 3.73E-06 3.43E-06 -4.80E-07 3.81E-08 -1.63E-09 3.10E-11 S4 -0.287 3.19E-04 6.04E-07 9.87E-07 3.98E-09 -1.17E-08 8.94E-10 -2.02E-11 S11 3.373 -2.44E-03 -3.17E-06 -7.20E-06 1.05E-06 -1.92E-07 1.65E-08 -6.79E-10 S12 0.564 -4.75E-03 -2.81E-05 1.96E-06 -1.39E-06 8.55E-08 -1.96E-09 -5.39E-11 S13 -3.481 -2.10E-03 -1.65E-04 2.07E-05 -2.33E-06 1.58E-07 -5.55E-09 4.00E-10 S14 -27.569 -2.49E-03 -8.88E-05 9.17E-06 -5.37E-07 1.76E-08 4.93E-11 2.46E-11 S15 -17.298 8.18E-04 -3.25E-04 1.54E-05 -6.05E-07 1.68E-08 -1.59E-10 -3.07E-12 S16 -9.589 -9.10E-04 -8.38E-05 -4.75E-06 4.83E-07 -2.08E-08 5.53E-10 -5.89E-12 S17 -6.011 -2.59E-03 -6.32E-05 8.23E-06 -4.75E-07 7.77E-10 6.81E-10 -1.39E-11 S18 -8.825 -2.70E-03 -1.60E-05 4.76E-06 -1.62E-07 -1.21E-10 8.66E-11 -1.13E-12

[0115] Table 4

[0116] Figure 5 shows a distortion curve diagram of the optical lens according to Example 2 of the present application, Figure 6 FIG. 4 shows a relative illumination curve diagram of an optical lens according to Embodiment 2 of the present application, wherein Figure 5 and Figure 6 It can be seen that the optical lens according to Example 2 of the present application has the characteristics of low distortion and high illumination, and can achieve good imaging quality.

[0117] Example 3

[0118] Figure 7 The structure diagram of the optical lens according to Embodiment 3 of the present application is shown below. Figure 7 Describe the optical lens according to Example 3 of the present application.

[0119] like Figure 7 As shown, the optical lens includes, from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, an aperture STO, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a filter and / or a protective glass C, and an imaging surface (IMA). The fourth lens L4 and the fifth lens L5 are doublet lenses.

[0120] In this embodiment, the first lens L1 has negative power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens L2 has negative power, its object side surface S3 is concave, and its image side surface S4 is convex. The third lens L3 has positive power, its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens L4 has negative power, its object side surface S8 is convex, and its image side surface S9 is concave. The fifth lens L5 has positive power, its object side surface S9 is convex, and its image side surface S10 is convex. The sixth lens L6 has negative power, its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens L7 has positive power, its object side surface S13 is convex, and its image side surface S14 is convex. The eighth lens L8 has negative power, its object side surface S15 is convex, and its image side surface S16 is concave. The ninth lens L9 has positive refractive power, and its object-side surface S17 is convex, and its image-side surface S18 is concave.

[0121] The distortion of the optical lens of this embodiment is -1.02%; the half field angle is 27.786°; and the half image height is 5.50 mm.

[0122] Table 5 shows the curvature radius R, thickness d, refractive index ND and Abbe number VD of each lens of the optical lens of Example 3.

[0123]

[0124] Table 5

[0125] In this embodiment, the object side surface and the image side surface of the second lens L2, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are all aspherical surfaces, and the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. Table 6 shows the cone coefficient k and the high-order coefficients A4, A6, A8, A9 that can be used for each aspherical mirror surface S3-S4, S11-S18 in this embodiment. 10 , A 12 , A 14 and A 16 .

[0126]

[0127]

[0128] Table 6

[0129] Figure 8 shows a distortion curve diagram of the optical lens according to Example 3 of the present application, Fig. 9 FIG. 4 shows a relative illumination curve diagram of an optical lens according to Embodiment 3 of the present application, wherein Figure 8 and Fig. 9It can be seen that the optical lens according to Example 3 of the present application has the characteristics of low distortion and high illumination, and can achieve good imaging quality.

[0130] Example 4

[0131] Fig.10 The structure diagram of the optical lens according to Embodiment 4 of the present application is shown below. Fig.10 Describe the optical lens according to Example 4 of the present application.

[0132] like Fig.10 As shown, the optical lens includes, from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, an aperture STO, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a filter and / or a protective glass C, and an imaging surface (IMA). The fourth lens L4 and the fifth lens L5 are doublet lenses.

[0133] In this embodiment, the first lens L1 has negative power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens L2 has positive power, its object side surface S3 is concave, and its image side surface S4 is convex. The third lens L3 has positive power, its object side surface S5 is convex, and its image side surface S6 is concave. The fourth lens L4 has negative power, its object side surface S8 is convex, and its image side surface S9 is concave. The fifth lens L5 has positive power, its object side surface S9 is convex, and its image side surface S10 is convex. The sixth lens L6 has negative power, its object side surface S11 is convex, and its image side surface S12 is concave. The seventh lens L7 has positive power, its object side surface S13 is convex, and its image side surface S14 is convex. The eighth lens L8 has negative power, its object side surface S15 is convex, and its image side surface S16 is concave. The ninth lens L9 has positive refractive power, and its object-side surface S17 is convex, and its image-side surface S18 is concave.

[0134] The distortion of the optical lens of this embodiment is -2.06%; the half field angle is 27.879°; and the half image height is 5.50 mm.

[0135] Table 7 shows the curvature radius R, thickness d, refractive index ND and Abbe number VD of each lens of the optical lens of Example 4.

[0136]

[0137]

[0138] Table 7

[0139] In this embodiment, the object side surface and the image side surface of the second lens L2, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are all aspherical surfaces, and the surface shape of each aspherical surface can be defined by the formula (1) given in the above embodiment 1. Table 8 shows the cone coefficient k and the high-order coefficients A4, A6, A8, A 10 , A 12 , A 14 and A 16 .

[0140] Face number k A4 A6 A8 A10 A12 A14 A16 S3 2.442 -3.88E-04 -9.52E-06 3.98E-06 -5.68E-07 4.70E-08 -2.19E-09 4.46E-11 S4 0.921 -2.70E-04 6.35E-06 -7.36E-07 1.89E-07 -1.94E-08 8.50E-10 -1.27E-11 S11 2.028 -3.69E-03 2.32E-05 -5.25E-06 1.18E-06 -2.44E-07 2.22E-08 -9.35E-10 S12 0.153 -6.09E-03 -2.32E-06 8.30E-06 -1.68E-06 6.94E-08 7.10E-09 -6.48E-10 S13 52.863 -2.04E-03 -1.37E-04 2.63E-05 -2.59E-06 1.83E-07 4.01E-09 -4.69E-10 S14 -99.000 -3.10E-03 3.74E-05 6.16E-06 -3.63E-07 2.81E-08 -1.96E-10 -1.25E-11 S15 -11.953 7.42E-04 -3.14E-04 1.60E-05 -5.68E-07 1.57E-08 -4.04E-10 1.00E-11 S16 -9.420 -1.06E-03 -7.97E-05 -4.28E-06 4.87E-07 -2.15E-08 5.40E-10 -4.70E-12 S17 -6.068 -2.30E-03 -4.72E-05 7.51E-06 -4.12E-07 1.09E-09 5.62E-10 -1.17E-11 S18 -11.523 -2.26E-03 -6.19E-05 8.90E-06 -2.64E-07 -2.27E-09 2.25E-10 -2.89E-12

[0141] Table 8

[0142] Fig.11 shows a distortion curve diagram of the optical lens according to Example 4 of the present application, Fig.12 FIG. 4 shows a relative illumination curve of an optical lens according to Embodiment 4 of the present application, wherein Fig.11 and Fig.12 It can be seen that the optical lens according to Example 4 of the present application has the characteristics of low distortion and high illumination, and can achieve good imaging quality.

[0143] In summary, Examples 1 to 4 respectively satisfy the relationship shown in Table 9 below.

[0144]

[0145]

[0146] Table 9

[0147] The present application also provides an electronic device, which may include an optical lens according to the above-mentioned embodiment of the present application and an imaging element for converting an optical image formed by the optical lens into an electrical signal.

[0148] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims

1. An optical lens, characterized in that: Along the optical axis from the object side to the image side, they include: A first lens having negative optical power, a second lens having positive or negative optical power, The third lens has positive power, The fourth lens has negative optical power, The fifth lens has positive refractive power, a sixth lens having negative optical power, The seventh lens has positive power, an eighth lens having negative optical power, and a ninth lens having positive refractive power; The effective focal length F3 of the third lens and the total effective focal length F of the optical lens satisfy: 0.7≤F3 / F≤1.

2.

2. The optical lens according to claim 1, characterized in that: The object side surface of the second lens is concave, and the image side surface is convex; The object side surface of the third lens is convex, and the image side surface is concave; The object side surface of the fourth lens is convex, and the image side surface is concave; The image side surface of the fifth lens is a convex surface, and the image side surface is a convex surface; The object side surface of the sixth lens is convex, and the image side surface is concave; The object side surface of the seventh lens is convex, and the image side surface is convex; The object side surface of the eighth lens is convex, and the image side surface is concave; and The object side surface of the ninth lens is convex, and the image side surface is concave.

3. The optical lens according to claim 1, characterized in that: The fourth lens and the fifth lens are doublet lenses glued to each other.

4. The optical lens according to any one of claims 1 to 3, characterized in that: The effective focal length F1 of the first lens and the total effective focal length F of the optical lens satisfy: -1.6≤F1 / F≤-1.

14.

5. The optical lens according to any one of claims 1 to 3, characterized in that: The curvature radius R21 of the object side surface of the second lens and the total effective focal length F of the optical lens satisfy: -1.1≤R21 / F≤-0.

5.

6. The optical lens according to any one of claims 1 to 3, characterized in that: The effective focal length F4 of the fourth lens and the total effective focal length F of the optical lens satisfy: -0.9≤F4 / F≤-0.

4.

7. The optical lens according to any one of claims 1 to 3, characterized in that: The effective focal length F5 of the fifth lens and the total effective focal length F of the optical lens satisfy: 0.4≤F5 / F≤0.

8.

8. The optical lens according to any one of claims 1 to 3, characterized in that: The effective focal length F6 of the sixth lens and the total effective focal length F of the optical lens satisfy: -2.33≤F6 / F≤-1.

7.

9. The optical lens according to any one of claims 1 to 3, characterized in that: The effective focal length F7 of the seventh lens and the total effective focal length F of the optical lens satisfy: 0.41≤F7 / F≤8.

69.

10. The optical lens according to any one of claims 1 to 3, characterized in that: The effective focal length F8 of the eighth lens and the total effective focal length F of the optical lens satisfy: -3.84≤F8 / F≤-1.73.

Images