Optical lens

Abstract

The utility model discloses an optical lens. The optical lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along an optical axis, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the fourth lens has positive focal power; the fifth lens has positive focal power; the object side surface of the sixth lens is a concave surface, and the image side surface of the sixth lens is a convex surface; the effective focal length f6 of the sixth lens and the total focal length f of the optical lens meet the condition that f6 / f is larger than or equal to-9.1 and smaller than or equal to-3.9.

Description

Technical Field

[0001] This 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 shooting fields such as video conferencing, online teaching, and webcasting, and people's requirements for video lenses are getting higher and higher.

[0003] However, the existing video lenses at least still have the following deficiencies: 1) Some existing lenses generally have problems of too long overall length and too large volume, resulting in too high cost and weight of the overall lens; 2) Some existing lenses have poor thermal stability and cannot meet the requirements of clear imaging in extreme temperature environments; 3) Some existing lenses have slightly larger aberrations, poor imaging quality, and insufficient distortion control, resulting in obvious deformation of the captured image and affecting the subsequent image processing; 4) Some existing lenses have a small depth-of-field range and cannot meet the requirements of clear imaging with a large depth of field. Summary of the Utility Model

[0004] This application provides an optical lens, which sequentially includes, 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, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with positive optical power, and a sixth lens with negative optical power; wherein, the object side surface of the second lens is convex and the image side surface is concave; the object side surface of the third lens is convex and the image side surface is concave; the object side surface of the sixth lens is concave and the image side surface is convex; the effective focal length f6 of the sixth lens and the total focal length f of the optical lens satisfy: -9.1 ≤ f6 / f ≤ -3.9.

[0005] In one embodiment, the object side surface of the first 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 convex; the object side surface of the fifth lens is convex and the image side surface is concave.

[0006] In one embodiment, the optical lens satisfies: -0.4 ≤ R11 / f1 ≤ -0.2, where R11 is the curvature radius of the object side surface of the first lens and f1 is the effective focal length of the first lens.

[0007] In one embodiment, the optical lens satisfies: 2.1 ≤ f2 / f ≤ 5.9, where f2 is the effective focal length of the second lens and f is the total focal length of the optical lens.

[0008] In one embodiment, the optical lens satisfies: -2.9 ≤ f2 / f3 ≤ -1.2, where f2 is the effective focal length of the second lens and f3 is the effective focal length of the third lens.

[0009] In one embodiment, the optical lens satisfies: 0.5 ≤ f4 / f ≤ 0.7, where f4 is the effective focal length of the fourth lens and f is the total focal length of the optical lens.

[0010] In one embodiment, the optical lens satisfies: 0.34 ≤ d4 / f4 ≤ 0.45, where d4 is the central thickness of the fourth lens on the optical axis and f4 is the effective focal length of the fourth lens.

[0011] In one embodiment, the optical lens satisfies: 2.9 ≤ f5 / f ≤ 7.0, where f5 is the effective focal length of the fifth lens and f is the total focal length of the optical lens.

[0012] In one embodiment, the optical lens satisfies: 0.45 ≤ fb / f ≤ 0.58, where fb is the combined focal length of the fourth, fifth, and sixth lenses and f is the total focal length of the optical lens.

[0013] In one embodiment, the optical lens satisfies: -0.15 ≤ (R52 + R61 + R62) / f56 ≤ 0.3, where R52 is the radius of curvature of the image side of the fifth lens, R61 is the radius of curvature of the object side of the sixth lens, R62 is the radius of curvature of the image side of the sixth lens, and f56 is the combined focal length of the fifth and sixth lenses.

[0014] In one embodiment, the optical lens satisfies: 12.0 ≤ (VD1 + VD4) / f ≤ 12.5, where VD1 is the Abbe number of the first lens and VD4 is the Abbe number of the fourth lens, and f is the total focal length of the optical lens.

[0015] In one embodiment, the optical lens satisfies: 3.8 ≤ dm / dn ≤ 5.1, where dm is the maximum value of the central thicknesses of the lenses on the optical axis from the first lens to the sixth lens, and dn is the minimum value of the central thicknesses of the lenses on the optical axis from the first lens to the sixth lens.

[0016] In one embodiment, the optical lens satisfies: 3.3 ≤ (R51 + R52) / d5 ≤ 4.5, where R51 is the radius of curvature of the object side of the fifth lens, R52 is the radius of curvature of the image side of the fifth lens, and d5 is the central thickness of the fifth lens on the optical axis.

[0017] In one embodiment, the optical lens satisfies: -2.8 ≤ fa / fb ≤ -1.8, where fa is the combined focal length of the first, second, and third lenses and fb is the combined focal length of the fourth, fifth, and sixth lenses.

[0018] In one embodiment, the optical lens satisfies: 1.9 ≤ 2×f×tan(FOV / 2) / (H / 2) ≤ 2.1, where FOV is the full field of view angle of the optical lens, and H is the full image height of the optical lens.

[0019] In one embodiment, the optical lens satisfies: 1.6 ≤ TTL / f ≤ 2.0, where TTL is the total optical length of the optical lens, and f is the total focal length of the optical lens.

[0020] In one embodiment, the optical lens satisfies: 0.25 ≤ BFL / TTL ≤ 0.30, where BFL is the back focal length of the optical lens, and TTL is the total optical length of the optical lens.

[0021] In one embodiment, the optical lens satisfies: 0.3 ≤ ENPD / f ≤ 0.4, where ENPD is the entrance pupil diameter of the optical lens, and f is the total focal length of the optical lens.

[0022] For the optical lens provided in this application, by optimizing the optical power and surface shape of each lens, and reasonably allocating the ratio range of the effective focal length of the sixth lens to the total focal length of the optical lens, it is beneficial to correct the residual spherical aberration, coma, and astigmatism of the system, improve the imaging performance of the optical system, and enable the optical lens to meet the resolution of chips with more than 8 million pixels; at the same time, it effectively corrects optical distortion, making the absolute value of optical distortion ≤ 0.8%, achieving the beneficial effect of low distortion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, objects, and advantages of this application will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings. Among them:

[0024] Figure 1A It is a schematic structural diagram of the optical lens according to Embodiment 1 of this application;

[0025] Figure 1B It is a distortion diagram of the optical lens according to Embodiment 1 of this application;

[0026] Figure 2A It is a schematic structural diagram of the optical lens according to Embodiment 2 of this application;

[0027] Figure 2B It is a distortion diagram of the optical lens according to Embodiment 2 of this application;

[0028] Figure 3A It is a schematic structural diagram of the optical lens according to Embodiment 3 of this application;

[0029] Figure 3B It is a distortion diagram of the optical lens according to Embodiment 3 of this application;

[0030] Figure 4A To show a schematic structural diagram of an optical lens according to Embodiment 4 of the present application; and

[0031] Figure 4B To show a distortion diagram of the optical lens according to Embodiment 4 of the present application. Detailed implementation manners

[0032] 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 the exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0033] It should be noted that in this specification, the expressions such as the first, the second, and the third are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0034] In the drawings, for the sake of convenience of illustration, the thickness, size, and shape of the lens have been slightly exaggerated. Specifically, the spherical or aspherical shapes shown in the drawings are shown by way of example. That is, the spherical or aspherical shapes are not limited to the spherical or aspherical shapes shown in the drawings. The drawings are only for illustration and are not drawn strictly to scale.

[0035] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side surface of the lens, and the surface of each lens closest to the imaging side is called the image side surface of the lens.

[0036] It should also be understood that the terms "comprise", "comprising", "have", "including" and / or "including having", 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 an expression such as "at least one of..." appears after the list of listed features, it modifies the entire list of listed features, rather than modifying a single element in the list. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0037] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formalized sense unless expressly so defined herein.

[0038] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The following will detail this application with reference to the accompanying drawings and in conjunction with the embodiments.

[0039] The features, principles, and other aspects of this application will be described in detail below.

[0040] An optical lens according to an exemplary embodiment of this application may include six lenses having optical powers, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. These six lenses are arranged in sequence along the optical axis from the object side to the image side. There may be a spacing distance between any two adjacent lenses among the first lens to the sixth lens.

[0041] In an exemplary embodiment, the optical lens may further include a photosensitive element disposed on the image side of the sixth lens. Optionally, the photosensitive element disposed on the image side of the sixth lens may be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor device (CMOS).

[0042] In an exemplary embodiment, a diaphragm for restricting light beams may be disposed between the third lens and the fourth lens to further improve the imaging quality of the optical lens. However, it should be noted that the position of the diaphragm disclosed herein is only an example and not a limitation; in alternative embodiments, the diaphragm may also be disposed at other positions according to actual needs.

[0043] In an exemplary embodiment, the first lens may have a negative optical power, with its object side surface being convex and its image side surface being concave. This setting of the first lens is beneficial to the light collection of the optical lens, can effectively increase the field of view range and illuminance, and make the full field illuminance ≥ 85%.

[0044] In an exemplary embodiment, the second lens may have a positive optical power, with its object side surface being convex and its image side surface being concave. This setting of the second lens can effectively control the trend of marginal field light rays and avoid the generation of high-order aberrations; at the same time, it is beneficial to balance the field curvature of the optical lens and improve the imaging quality of the optical lens.

[0045] In an exemplary embodiment, the third lens may have a negative optical power, with its object side being convex and its image side being concave. This arrangement of the third lens can effectively control the trend of light rays, achieving a smooth transition of light rays by compressing the angle of incident light rays; at the same time, by introducing positive spherical aberration, the spherical aberration generated by each lens in the optical lens can be effectively balanced.

[0046] In an exemplary embodiment, the fourth lens may have a positive optical power, with its object side being convex and its image side being convex. The fourth lens bears a relatively large optical power in the entire system, which is beneficial to balancing the spherical aberration, coma, and astigmatism of the optical lens and improving the imaging quality of the optical lens; at the same time, the fourth lens can adopt a material with stable thermal expansion, which helps to suppress the focus drift of the lens in high and low temperature environments, achieving high imaging quality within a large temperature range (for example, -30°C to 70°C).

[0047] In an exemplary embodiment, the fifth lens may have a positive optical power, with its object side being convex and its image side being concave. This arrangement of the fifth lens can effectively control the trend of light rays, enabling the light rays to smoothly transition to the rear of the optical lens, thereby being beneficial to compensating for the spherical aberration of the optical lens.

[0048] In an exemplary embodiment, the sixth lens may have a negative optical power, with its object side being concave and its image side being convex. This arrangement of the sixth lens is beneficial to correcting the residual spherical aberration, coma, and astigmatism of the system, greatly improving the imaging performance of the optical lens; at the same time, it can effectively correct the optical distortion of the optical lens, making the absolute value of the optical distortion ≤ 0.8%.

[0049] In an exemplary embodiment, the optical lens according to the present application may satisfy: -9.1 ≤ f6 / f ≤ -3.9, where f6 is the effective focal length of the sixth lens and f is the total focal length of the optical lens. Satisfying -9.1 ≤ f6 / f ≤ -3.9 and reasonably allocating the ratio range of the effective focal length of the sixth lens to the total focal length of the optical lens is beneficial to correcting the residual spherical aberration, coma, and astigmatism of the system, improving the imaging performance of the optical system, enabling the optical lens to satisfy the resolution of a chip with more than 8 million pixels; at the same time, it can effectively correct the optical distortion, making the absolute value of the optical distortion ≤ 0.8%, achieving a low distortion effect.

[0050] In an exemplary embodiment, the optical lens according to the present application may satisfy: -0.4 ≤ R11 / f1 ≤ -0.2, where R11 is the radius of curvature of the object side of the first lens and f1 is the effective focal length of the first lens. Satisfying -0.4 ≤ R11 / f1 ≤ -0.2 and reasonably allocating the ratio range of the radius of curvature of the object side of the first lens to its effective focal length is beneficial for the optical lens to converge the incident light rays from more fields of view, increasing the field of view angle of the optical lens and greatly improving the lens illuminance, making the full-field illuminance ≥ 85%.

[0051] In an exemplary embodiment, the optical lens according to the present application may satisfy: 2.1 ≤ f2 / f ≤ 5.9, where f2 is the effective focal length of the second lens and f is the total focal length of the optical lens. Satisfying 2.1 ≤ f2 / f ≤ 5.9 and reasonably allocating the ratio range of the effective focal length of the second lens to the total focal length of the optical lens is beneficial to the smooth transition of the light trend in the marginal field of view and avoids the generation of high-order aberrations; at the same time, it is beneficial to balance the field curvature of the optical lens and improve the imaging quality of the optical lens.

[0052] In an exemplary embodiment, the optical lens according to the present application may satisfy: -2.9 ≤ f2 / f3 ≤ -1.2, where f2 is the effective focal length of the second lens and f3 is the effective focal length of the third lens. Satisfying -2.9 ≤ f2 / f3 ≤ -1.2 and reasonably allocating the ratio range of the effective focal length of the second lens to the effective focal length of the third lens is beneficial to balancing the spherical aberration and off-axis aberration of the optical lens, and at the same time, it can effectively control the optical distortion in the marginal field of view.

[0053] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.5 ≤ f4 / f ≤ 0.7, where f4 is the effective focal length of the fourth lens and f is the total focal length of the optical lens. Satisfying 0.5 ≤ f4 / f ≤ 0.7 and reasonably allocating the ratio range of the effective focal length of the fourth lens to the total focal length of the optical lens is beneficial to balancing the spherical aberration, coma and astigmatism of the optical lens and improving the imaging quality of the optical lens.

[0054] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.34 ≤ d4 / f4 ≤ 0.45, where d4 is the central thickness of the fourth lens on the optical axis and f4 is the effective focal length of the fourth lens. Satisfying 0.34 ≤ d4 / f4 ≤ 0.45 and reasonably allocating the ratio range of the central thickness of the fourth lens to its focal length is beneficial to correcting the aberration in the central field of view region; at the same time, it helps to achieve thermal compensation of the optical lens and reduce the tolerance sensitivity of this lens.

[0055] In an exemplary embodiment, the optical lens according to the present application may satisfy: 2.9 ≤ f5 / f ≤ 7.0, where f5 is the effective focal length of the fifth lens and f is the total focal length of the optical lens. Satisfying 2.9 ≤ f5 / f ≤ 7.0 and reasonably allocating the ratio range of the effective focal length of the fifth lens to the total focal length of the optical lens is beneficial to compensating for the spherical aberration generated by the lens in front of the fifth lens, improving the imaging quality of the optical lens, and enabling the optical lens to satisfy the resolution of a chip with more than 8 million pixels.

[0056] In an exemplary embodiment, the optical lens according to the present application may satisfy: 0.45 ≤ fb / f ≤ 0.58, where fb is the combined focal length of the fourth lens, the fifth lens, and the sixth lens, and f is the total focal length of the optical lens. Satisfying 0.45 ≤ fb / f ≤ 0.58 and reasonably allocating the ratio range of the combined focal length of the fourth lens, the fifth lens, and the sixth lens to the total focal length of the optical lens can make the light rays in each field of view smoothly transition to the rear of the optical lens, effectively balancing various aberrations generated by the first three lenses (i.e., the first lens to the third lens) of the optical lens, which is beneficial to improving the imaging quality of the optical lens.

[0057] In an exemplary embodiment, the optical lens according to the present application may satisfy: -0.15 ≤ (R52 + R61 + R62) / f56 ≤ 0.3, where R52 is the curvature radius of the image side of the fifth lens, R61 is the curvature radius of the object side of the sixth lens, R62 is the curvature radius of the image side of the sixth lens, and f56 is the combined focal length of the fifth lens and the sixth lens. Satisfying -0.15 ≤ (R52 + R61 + R62) / f56 ≤ 0.3 is beneficial for the light rays to smoothly enter the imaging surface, thereby effectively reducing the deflection angle of the marginal light rays in the fifth lens and the sixth lens, improving the imaging quality and illuminance of the marginal field of view; at the same time, it also helps to reduce the risk of strong reflection energy ghost images.

[0058] In an exemplary embodiment, the optical lens according to the present application may satisfy: 12.0 ≤ (VD1 + VD4) / f ≤ 12.5, where VD1 is the Abbe number of the first lens, VD4 is the Abbe number of the fourth lens, and f is the total focal length of the optical lens. Satisfying 12.0 ≤ (VD1 + VD4) / f ≤ 12.5 and reasonably allocating the ratio range of the sum of the Abbe numbers of the first lens and the fourth lens to the total focal length of the optical lens can effectively correct the system chromatic aberration, which is beneficial to improving the color saturation of the lens.

[0059] In an exemplary embodiment, the optical lens according to the present application may satisfy: 3.8 ≤ dm / dn ≤ 5.1, where dm is the maximum value of the central thickness of each lens on the optical axis among the first lens to the sixth lens, and dn is the minimum value of the central thickness of each lens on the optical axis among the first lens to the sixth lens. Satisfying 3.8 ≤ dm / dn ≤ 5.1 and reasonably allocating the ratio range of the maximum value to the minimum value of the central thickness of each lens among the first lens to the sixth lens is beneficial for realizing small changes in the light rays in each lens at high and low temperatures, enabling the lens to achieve athermalization.

[0060] In an exemplary embodiment, the optical lens according to the present application can satisfy: 3.3 ≤ (R51 + R52) / d5 ≤ 4.5, where R51 is the radius of curvature of the object side of the fifth lens, R52 is the radius of curvature of the image side of the fifth lens, and d5 is the central thickness of the fifth lens on the optical axis. Satisfying 3.3 ≤ (R51 + R52) / d5 ≤ 4.5 and reasonably distributing the ratio of the sum of the radius of curvature of the object side of the fifth lens and the radius of curvature of the image side of the fifth lens to the central thickness of the fifth lens on the optical axis is beneficial to constraining the lens shape of the fifth lens and making it easy to process and form.

[0061] In an exemplary embodiment, the optical lens according to the present application can satisfy: -2.8 ≤ fa / fb ≤ -1.8, where fa is the combined focal length of the first lens, the second lens, and the third lens, and fb is the combined focal length of the fourth lens, the fifth lens, and the sixth lens. The first lens, the second lens, and the third lens are placed on the object side of the aperture, and the fourth lens, the fifth lens, and the sixth lens are placed on the image side of the aperture. Satisfying -2.8 ≤ fa / fb ≤ -1.8 and reasonably distributing the positive and negative of the optical power of the lens group on the object side of the aperture and the lens group on the image side of the aperture is beneficial to controlling the trend of light rays, making the light rays travel more smoothly, reducing the sensitivity of the system, and improving the imaging quality of the system.

[0062] In an exemplary embodiment, the optical lens according to the present application can satisfy: 1.9 ≤ 2×f×tan(FOV / 2) / (H / 2) ≤ 2.1, where FOV is the full field of view angle of the optical lens and H is the full image height of the optical lens. Satisfying 1.9 ≤ 2×f×tan(FOV / 2) / (H / 2) ≤ 2.1 and reasonably distributing the ratio of the total focal length of the optical lens to the field of view angle, making the ratio of the actual image height to the theoretical image height smaller, is beneficial to achieving low distortion and making the absolute value of optical distortion ≤ 0.8%.

[0063] In an exemplary embodiment, the optical lens according to the present application can satisfy: 1.6 ≤ TTL / f ≤ 2.0, where TTL is the overall optical length of the optical lens and f is the total focal length of the optical lens. Satisfying 1.6 ≤ TTL / f ≤ 2.0 and reasonably setting the overall optical length of the optical lens when the total focal length of the optical lens is fixed is beneficial to realizing the miniaturization of the lens and making TTL ≤ 22.52 mm.

[0064] In an exemplary embodiment, the optical lens according to the present application can satisfy: 0.25 ≤ BFL / TTL ≤ 0.30, where BFL is the back focal length of the optical lens and TTL is the overall optical length of the optical lens. Satisfying 0.25 ≤ BFL / TTL ≤ 0.30 and controlling the back focal length of the optical lens on the basis of realizing miniaturization, making the back focal length of the lens longer, helps to reserve space for the installation of optical elements, facilitates the assembly of the optical lens, avoids interference, and improves the assembly yield of the optical lens.

[0065] In an exemplary embodiment, the optical lens according to the present application can satisfy: 0.3 ≤ ENPD / f ≤ 0.4, where ENPD is the entrance pupil diameter of the optical lens, and f is the total focal length of the optical lens. By satisfying 0.3 ≤ ENPD / f ≤ 0.4, by controlling the size of the entrance pupil diameter of the optical lens, the optical lens has a relatively large aperture value, which is beneficial to achieving clear imaging with a large depth of field from 6m to 18m.

[0066] In an exemplary embodiment, the optical lens of the present application has the characteristic of a large depth of field and can satisfy large-depth-of-field imaging in the range of 6m to 18m.

[0067] In an exemplary embodiment, the optical lens of the present application has the characteristic of high illuminance, and its full-field illuminance ≥ 85%.

[0068] In an exemplary embodiment, the optical lens of the present application has the characteristic of low distortion, and the absolute value of its optical distortion ≤ 0.80%.

[0069] In an exemplary embodiment, the chief ray angle of incidence CRA of the optical lens of the present application < 15°.

[0070] In an exemplary embodiment, the optical lens of the present application has the characteristic of high resolution and can satisfy the resolution of a chip with more than 8 million pixels.

[0071] In an exemplary embodiment, the full-field of view FOV of the optical lens of the present application can satisfy 31° ≤ FOV ≤ 35°.

[0072] In an exemplary embodiment, the optical lens of the present application has the characteristic of miniaturization, and its total optical length TTL (i.e., the distance from the object side surface of the first lens to the imaging surface of the optical lens on the optical axis) can satisfy TTL ≤ 22.52 mm.

[0073] In an exemplary embodiment, the back focal length BFL of the optical lens of the present application (i.e., the distance from the image side surface of the sixth lens to the imaging surface of the optical lens on the optical axis) can satisfy: 5.5 mm ≤ BFL ≤ 6.0 mm. The optical lens of the present application has a relatively long back focal length, which helps to reserve space for the installation of optical elements, facilitates the assembly of the optical lens, avoids interference, and improves the assembly yield of the optical lens.

[0074] In an exemplary embodiment, as needed, the optical lens of the present application may further include a filter and / or a protective glass disposed between the last lens and the imaging surface. The filter can filter light rays with different wavelengths, and the protective glass can prevent damage to the image-side elements (such as chips) of the optical lens.

[0075] In an exemplary embodiment, each lens of the optical lens may be a spherical lens or an aspherical lens. The present application does not specifically limit the specific number of spherical lenses and aspherical lenses. When focusing on reflecting the imaging quality, the number of aspherical lenses can be increased, and even all lenses can be aspherical lenses. The characteristic of an aspherical lens is that the curvature continuously changes from the center to the periphery of the lens. Different from a spherical lens with a constant curvature from the center to the periphery, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality of the lens. Optionally, in the optical lens according to the present application, the object side and the image side of the first lens and the fourth lens are spherical mirror surfaces, and the object side and the image side of the second lens, the third lens, the fifth lens, and the sixth lens are all aspherical mirror surfaces.

[0076] Through reasonable settings of the optical power, shape, and related parameters of each lens, the optical lens according to the above embodiment of the present application achieves at least one beneficial effect such as miniaturization (TTL≤22.52 mm), low distortion (absolute value of optical distortion≤0.80%), high illuminance (total field illuminance≥85%), large depth of field (6 m to 18 m), high resolution (more than 8 million pixels), and good thermal stability (-30°C to 70°C).

[0077] However, those skilled in the art should understand 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 six lenses are described as an example in the embodiment, the optical lens is not limited to including six lenses. If necessary, the optical lens may further include other numbers of lenses. The following further describes specific embodiments of the optical lens applicable to the above embodiment with reference to the drawings.

[0078] Example 1

[0079] The following refers to Figure 1A and Figure 1B describe the optical lens according to Embodiment 1 of the present application. Figure 1A FIG. shows a schematic structural diagram of the optical lens according to Embodiment 1 of the present application.

[0080] As Figure 1A shown, the optical lens sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 along the optical axis from the object side to the image side.

[0081] The first lens L1 has a negative optical power, its object side S1 is a convex surface, and its image side S2 is a concave surface.

[0082] The second lens L2 has a positive optical power, its object side S3 is convex, and its image side S4 is concave.

[0083] The third lens L3 has a negative optical power, its object side S5 is convex, and its image side S6 is concave.

[0084] The fourth lens L4 has a positive optical power, its object side S8 is convex, and its image side S9 is convex.

[0085] The fifth lens L5 has a positive optical power, its object side S10 is convex, and its image side S11 is concave.

[0086] The sixth lens L6 has a negative optical power, its object side S12 is concave, and its image side S13 is convex.

[0087] The optical lens further includes a stop STO disposed between the third lens L3 and the fourth lens L4.

[0088] Optionally, the optical lens may further include a filter C having an object side S14 and an image side S15 and / or a protective glass (not shown) having an object side and an image side. The filter C can be used to correct color deviation, and the protective glass can also be used to protect the image sensing chip located at the imaging surface IMA. The light from the object sequentially passes through the surfaces S1 to S15 and finally forms an image on the imaging surface IMA.

[0089] Table 1 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens of the optical lens of Example 1, where the units of the radius of curvature and thickness / distance are both millimeters (mm).

[0090]

[0091] Table 1

[0092] In Example 1, the first lens and the fourth lens are spherical lenses, and the second lens, the third lens, the fifth lens, and the sixth lens are all aspherical lenses. The surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

[0093]

[0094] where x is the sagitta, the distance from the vertex of the aspherical surface, at the position of height h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface. Table 2 gives the conic coefficient k and the higher-order term coefficients A4, A6, A8, A

[0094] ,

[0093] , ,

[0091] ,

[0092] ,

[0090] , 12 ,

[0089] , , ,

[0088] ,

[0087] , , , , , 10 , , , and A 12 .

[0095] Face number k A4 A6 A8 A10 A12 S3 -1.78 2.06E-03 -5.49E-05 3.90E-06 -3.56E-07 0.00E+00 S4 -14.55 3.70E-03 -9.63E-05 -3.51E-06 -9.36E-08 0.00E+00 S5 -5.73 2.14E-03 -2.77E-05 -4.36E-06 3.64E-07 0.00E+00 S6 -2.26 2.28E-03 9.40E-06 4.69E-07 -3.18E-07 0.00E+00 S10 0.42 -1.46E-03 -9.53E-06 3.51E-06 0.00E+00 0.00E+00 S11 0.72 -4.57E-03 -1.67E-04 6.17E-06 0.00E+00 0.00E+00 S12 -0.04 -6.65E-03 -2.36E-04 -2.07E-05 5.24E-06 0.00E+00 S13 -1.82 -3.19E-03 3.20E-05 5.67E-06 3.25E-07 0.00E+00

[0096] Table 2

[0097] Figure 1B is the distortion diagram of the optical lens of Embodiment 1. According to Figure 1B it can be seen that the optical lens given in Embodiment 1 has the characteristic of low distortion and can achieve good imaging quality.

[0098] Example 2

[0099] The following refers to Figure 2A and Figure 2B to describe the optical lens according to Embodiment 2 of the present application. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to those in Embodiment 1 will be omitted. Figure 2A shows a schematic structural diagram of the optical lens according to Embodiment 2 of the present application.

[0100] As Figure 2A shown, the optical lens sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 along the optical axis from the object side to the image side.

[0101] The first lens L1 has a negative optical power, its object side S1 is a convex surface, and its image side S2 is a concave surface.

[0102] The second lens L2 has a positive optical power, its object side S3 is a convex surface, and its image side S4 is a concave surface.

[0103] The third lens L3 has a negative optical power, its object side S5 is a convex surface, and its image side S6 is a concave surface.

[0104] The fourth lens L4 has a positive optical power, its object side S8 is a convex surface, and its image side S9 is a convex surface.

[0105] The fifth lens L5 has a positive optical power, its object side S10 is a convex surface, and its image side S11 is a concave surface.

[0106] The sixth lens L6 has a negative optical power, its object side S12 is a concave surface, and its image side S13 is a convex surface.

[0107] The optical lens further includes a diaphragm STO disposed between the third lens L3 and the fourth lens L4.

[0108] Optionally, the optical lens may further include a filter C having an object side S14 and an image side S15 and / or a protective glass (not shown) having an object side and an image side. The filter C can be used to correct color deviation, and the protective glass can also be used to protect the image sensing chip located at the imaging surface IMA. Light from the object sequentially passes through the surfaces S1 to S15 and finally forms an image on the imaging surface IMA.

[0109] Table 3 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens of the optical lens of Example 2, where the units of the radius of curvature and thickness / distance are both millimeters (mm). Table 4 shows the conic coefficient k and the high-order term coefficients of each aspherical mirror surface that can be used in Example 2, where each aspherical surface type can be defined by the formula (1) given in the above Example 1.

[0110]

[0111]

[0112] Table 3

[0113] Face number k A4 A6 A8 A10 A12 S3 -6.54 2.26E-03 3.16E-05 -1.82E-05 4.33E-07 -2.29E-08 S4 -18.73 3.21E-03 2.27E-05 -2.14E-05 -1.25E-06 9.17E-08 S5 -9.57 1.43E-03 3.23E-05 -9.00E-07 -1.14E-06 6.52E-08 S6 -4.32 9.52E-04 1.40E-04 -1.36E-05 -1.14E-07 3.78E-08 S10 -0.14 -2.68E-03 7.04E-05 4.12E-06 3.09E-07 0.00E+00 S11 1.33 -7.67E-03 -4.26E-05 4.65E-06 -4.29E-07 0.00E+00 S12 0.57 -7.97E-03 -1.05E-04 2.56E-05 3.38E-06 3.95E-07 S13 0.21 -4.02E-03 7.80E-05 1.44E-05 -9.23E-07 6.05E-08

[0114] Table 4

[0115] Figure 2B is the distortion diagram of the optical lens of Example 2. According to Figure 2B it can be seen that the optical lens given in Example 2 has the characteristic of low distortion and can achieve good imaging quality.

[0116] Example 3

[0117] The following refers to Figure 3A and Figure 3B to describe the optical lens according to Embodiment 3 of the present application. Figure 3A shows a schematic structural diagram of the optical lens according to Embodiment 3 of the present application.

[0118] As Figure 3A shown, the optical lens sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 along the optical axis from the object side to the image side.

[0119] The first lens L1 has a negative optical power, its object side S1 is a convex surface, and its image side S2 is a concave surface.

[0120] The second lens L2 has a positive optical power, its object side S3 is a convex surface, and its image side S4 is a concave surface.

[0121] The third lens L3 has a negative optical power, its object side S5 is a convex surface, and its image side S6 is a concave surface.

[0122] The fourth lens L4 has a positive optical power, its object side S8 is convex, and its image side S9 is convex.

[0123] The fifth lens L5 has a positive optical power, its object side S10 is convex, and its image side S11 is concave.

[0124] The sixth lens L6 has a negative optical power, its object side S12 is concave, and its image side S13 is convex.

[0125] The optical lens further includes a diaphragm STO disposed between the third lens L3 and the fourth lens L4.

[0126] Optionally, the optical lens may further include a filter C having an object side S14 and an image side S15 and / or a protective glass (not shown) having an object side and an image side. The filter C can be used to correct color deviation, and the protective glass can also be used to protect the image sensing chip located at the imaging surface IMA. The light from the object sequentially passes through the surfaces S1 to S15 and finally forms an image on the imaging surface IMA.

[0127] Table 5 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens of the optical lens of Embodiment 3, where the units of the radius of curvature and thickness / distance are both millimeters (mm). Table 6 shows the conic coefficient k and the high-order term coefficients of each aspherical mirror surface that can be used in Embodiment 3, where each aspherical surface type can be defined by the formula (1) given in the above Embodiment 1.

[0128]

[0129] Table 5

[0130] Face number k A4 A6 A8 A10 A12 A14 S3 -7.96 1.93E-03 9.48E-05 -1.54E-05 5.07E-07 -3.86E-08 2.24E-10 S4 -47.74 2.17E-03 2.00E-04 -8.52E-06 -3.11E-06 1.22E-07 9.23E-10 S5 -5.84 -1.53E-03 5.19E-04 -4.54E-05 1.31E-06 -5.85E-08 3.29E-09 S6 -3.60 -1.09E-03 6.20E-04 -8.90E-05 6.49E-06 4.30E-07 -1.20E-07 S10 -0.63 -1.77E-03 1.23E-05 1.05E-05 -2.35E-08 -3.06E-08 0.00E+00 S11 0.56 -4.93E-03 -8.47E-05 1.43E-05 2.05E-06 -3.97E-07 0.00E+00 S12 -2.05 -4.03E-03 -1.24E-04 7.76E-05 -1.18E-05 3.85E-07 2.06E-08 S13 -3.07 -2.66E-03 -7.88E-06 2.55E-05 -3.75E-06 1.27E-07 1.42E-09

[0131] Table 6

[0132] Figure 3B is the distortion diagram of the optical lens of Embodiment 3. According to Figure 3B it can be seen that the optical lens given in Embodiment 3 has the characteristic of low distortion and can achieve good imaging quality.

[0133] Example 4

[0134] The following refers to Figure 4A and Figure 4B to describe the optical lens according to Embodiment 4 of the present application. Figure 4A shows a schematic structural diagram of the optical lens according to Embodiment 4 of the present application.

[0135] As Figure 4AAs shown, the optical lens sequentially includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 along the optical axis from the object side to the image side.

[0136] The first lens L1 has a negative optical power, its object side surface S1 is convex, and its image side surface S2 is concave.

[0137] The second lens L2 has a positive optical power, its object side surface S3 is convex, and its image side surface S4 is concave.

[0138] The third lens L3 has a negative optical power, its object side surface S5 is convex, and its image side surface S6 is concave.

[0139] The fourth lens L4 has a positive optical power, its object side surface S8 is convex, and its image side surface S9 is convex.

[0140] The fifth lens L5 has a positive optical power, its object side surface S10 is convex, and its image side surface S11 is concave.

[0141] The sixth lens L6 has a negative optical power, its object side surface S12 is concave, and its image side surface S13 is convex.

[0142] The optical lens further includes a stop STO disposed between the third lens L3 and the fourth lens L4.

[0143] Optionally, the optical lens may further include a filter C having an object side surface S14 and an image side surface S15 and / or a protective glass (not shown) having an object side surface and an image side surface. The filter C can be used to correct color deviation, and the protective glass can also be used to protect the image sensing chip located at the imaging surface IMA. Light from the object sequentially passes through the surfaces S1 to S15 and finally forms an image on the imaging surface IMA.

[0144] Table 7 shows the radius of curvature, thickness / distance, refractive index, and Abbe number of each lens of the optical lens of Example 4, where the units of the radius of curvature and thickness / distance are both millimeters (mm). Table 8 shows the conic coefficient k and the higher-order term coefficients of each aspherical mirror surface that can be used in Example 4, where each aspherical surface type can be defined by the formula (1) given in the above Example 1.

[0145]

[0146] Table 7

[0147] Face number k A4 A6 A8 A10 A12 S3 -10.97 2.57E-03 1.39E-04 -2.37E-05 6.51E-07 -4.25E-08 S4 -42.90 3.12E-03 1.61E-04 -1.23E-05 -3.53E-06 1.70E-07 S5 -3.27 -1.66E-03 5.00E-04 -5.04E-05 2.07E-06 -4.11E-08 S6 -2.94 -1.82E-03 7.58E-04 -1.07E-04 8.60E-06 -3.66E-07 S10 -0.64 -2.33E-03 1.15E-04 1.30E-05 8.75E-09 0.00E+00 S11 0.76 -8.48E-03 -4.61E-05 1.76E-05 -2.06E-07 0.00E+00 S12 0.28 -8.00E-03 -3.31E-04 6.27E-06 4.07E-06 1.51E-07 S13 -0.44 -3.39E-03 -5.53E-06 1.14E-05 -6.15E-07 2.70E-08

[0148] Table 8

[0149] Figure 4B is the distortion diagram of the optical lens of Example 4. According to Figure 4BIt can be seen that the optical lens given in Embodiment 4 has the characteristic of low distortion and can achieve good imaging quality.

[0150] In summary, Embodiments 1 to 4 respectively satisfy the relationships shown in Table 9 below.

[0151] Conditional / Example Example 1 Example 2 Example 3 Example 4 -0.4 ≤ R11 / f1 ≤ -0.2 -0.284 -0.311 -0.265 -0.275 2.1 ≤ f2 / f ≤ 5.9 2.460 5.680 3.263 4.617 -2.9 ≤ f2 / f3 ≤ -1.2 -1.584 -2.726 -1.716 -2.352 0.5 ≤ f4 / f ≤ 0.7 0.572 0.631 0.619 0.611 0.34 ≤ d4 / f4 ≤ 0.45 0.423 0.360 0.412 0.365 2.9 ≤ f5 / f ≤ 7.0 6.748 2.963 4.680 3.039 -9.1 ≤ f6 / f ≤ -3.9 -4.003 -5.300 -5.944 -7.152 0.45 ≤ fb / f ≤ 0.58 0.521 0.495 0.550 0.506 -0.15 ≤ (R52 + R61 + R62) / f56 ≤ 0.3 -0.098 0.280 0.058 0.242 12.0 ≤ (VD1 + VD4) / f ≤ 12.5 12.309 12.307 12.333 12.315 3.8 ≤ dm / dn ≤ 5.1 4.978 4.682 4.013 4.773 3.3 ≤ (R51 + R52) / d5 ≤ 4.5 4.336 3.515 4.100 3.603 -2.8 ≤ fa / fb ≤ -1.8 -2.226 -1.944 -2.469 -2.097 1.9 ≤ 2×f×tan(FOV / 2) / (H / 2) ≤ 2.1 2.010 2.008 2.010 2.010 1.6 ≤ TTL / f ≤ 2.0 1.763 1.822 1.825 1.823 0.25 ≤ BFL / TTL ≤ 0.30 0.271 0.262 0.262 0.262 0.3 ≤ ENPD / f ≤ 0.4 0.357 0.357 0.357 0.357

[0152] Table 9

[0153] The above description is only the preferred embodiments of the present application and the description of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solutions formed by the 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 technical solutions formed by mutually replacing the above features with the technical features (but not limited to) having similar functions disclosed in the present application.

Claims

1. An optical lens, characterized in that, The optical lens sequentially includes, 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, having a convex object side and a concave image side; A third lens with negative optical power, having a convex object side and a concave image side; A fourth lens with positive optical power; A fifth lens with positive optical power; and A sixth lens with negative optical power, having a concave object side and a convex image side; wherein, The effective focal length f6 of the sixth lens and the total focal length f of the optical lens satisfy: -9.1 ≤ f6 / f ≤ -3.

9.

2. The optical lens according to claim 1, wherein The object side of the first lens is convex and the image side is concave; The object side of the fourth lens is convex and the image side is convex; The object side of the fifth lens is convex and the image side is concave.

3. The optical lens according to claim 1, characterized in that Satisfies: -0.4 ≤ R11 / f1 ≤ -0.2, where R11 is the curvature radius of the object side of the first lens and f1 is the effective focal length of the first lens.

4. The optical lens according to claim 1, characterized in that, Satisfies: 2.1 ≤ f2 / f ≤ 5.9, where f2 is the effective focal length of the second lens and f is the total focal length of the optical lens.

5. The optical lens according to claim 1, characterized in that, Satisfies: -2.9 ≤ f2 / f3 ≤ -1.2, where f2 is the effective focal length of the second lens and f3 is the effective focal length of the third lens.

6. The optical lens according to claim 1, characterized in that, Satisfies: 0.5 ≤ f4 / f ≤ 0.7, where f4 is the effective focal length of the fourth lens and f is the total focal length of the optical lens.

7. The optical lens according to claim 1, wherein Satisfies: 0.34 ≤ d4 / f4 ≤ 0.45, where d4 is the central thickness of the fourth lens on the optical axis and f4 is the effective focal length of the fourth lens.

8. The optical lens according to claim 1, characterized in that Satisfies: 2.9 ≤ f5 / f ≤ 7.0, where f5 is the effective focal length of the fifth lens and f is the total focal length of the optical lens.

9. The optical lens according to claim 1, characterized in that, Satisfies: 0.45 ≤ fb / f ≤ 0.58, where fb is the combined focal length of the fourth lens, the fifth lens and the sixth lens, and f is the total focal length of the optical lens.

10. The optical lens according to any one of claims 1-9, characterized in that, Satisfies: -0.15 ≤ (R52 + R61 + R62) / f56 ≤ 0.3, where R52 is the curvature radius of the image side of the fifth lens, R61 is the curvature radius of the object side of the sixth lens, R62 is the curvature radius of the image side of the sixth lens, and f56 is the combined focal length of the fifth lens and the sixth lens.

11. The optical lens according to any one of claims 1-9, characterized in that, Satisfies: 12.0 ≤ (VD1 + VD4) / f ≤ 12.5, where VD1 is the Abbe number of the first lens, VD4 is the Abbe number of the fourth lens, and f is the total focal length of the optical lens.

12. The optical lens according to any one of claims 1-9, characterized in that, Satisfies: 3.8 ≤ dm / dn ≤ 5.1, where dm is the maximum value of the central thicknesses of the lenses from the first lens to the sixth lens on the optical axis, and dn is the minimum value of the central thicknesses of the lenses from the first lens to the sixth lens on the optical axis.

13. The optical lens according to any one of claims 1-9, characterized in that, Satisfied: 3.3 ≤ (R51 + R52) / d5 ≤ 4.5, where R51 is the radius of curvature of the object side surface of the fifth lens, R52 is the radius of curvature of the image side surface of the fifth lens, and d5 is the central thickness of the fifth lens on the optical axis.

14. The optical lens according to any one of claims 1-9, characterized in that, Satisfied: -2.8 ≤ fa / fb ≤ -1.8, where fa is the combined focal length of the first lens, the second lens, and the third lens, and fb is the combined focal length of the fourth lens, the fifth lens, and the sixth lens.

15. The optical lens according to any one of claims 1-9, characterized in that, Satisfied: 1.9 ≤ 2×f×tan(FOV / 2) / (H / 2) ≤ 2.1, where FOV is the full field of view angle of the optical lens, and H is the full image height of the optical lens.

16. The optical lens according to any one of claims 1-9, characterized in that, Satisfied: 1.6 ≤ TTL / f ≤ 2.0, where TTL is the overall optical length of the optical lens, and f is the total focal length of the optical lens.

17. The optical lens according to any one of claims 1-9, characterized in that, Satisfied: 0.25 ≤ BFL / TTL ≤ 0.30, where BFL is the back focal length of the optical lens, and TTL is the overall optical length of the optical lens.

18. The optical lens according to any one of claims 1-9, characterized in that, Satisfied: 0.3 ≤ ENPD / f ≤ 0.4, where ENPD is the entrance pupil diameter of the optical lens, and f is the total focal length of the optical lens.

Images