A fisheye lens

Abstract

The application discloses a fisheye lens, which comprises, in sequence from the object side to the image side along the optical axis, a first lens with negative refractive power, the object side of which is a convex surface and the image side of which is a concave surface; a second lens with refractive power; a third lens with refractive power; a fourth lens with refractive power, the refractive power of which is opposite to that of the third lens; a fifth lens with positive refractive power, the object side of which is a convex surface and the image side of which is a convex surface; a sixth lens with positive refractive power, the object side of which is a convex surface and the image side of which is a convex surface; a seventh lens with negative refractive power, the object side of which is a concave surface and the image side of which is a concave surface; and an eighth lens with positive refractive power, the object side of which is a convex surface and the image side of which is a convex surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical elements, and more particularly to a fisheye lens. BACKGROUND

[0002] With the continuous development of existing image processing algorithms and AI technology, in recent years, the application of fisheye lens has become more diversified and is widely used in action cameras, drones, smart doorbells and smart homes, etc. Therefore, the requirements for fisheye lens are becoming higher and higher.

[0003] However, the existing fisheye lens still has many shortcomings. For example, although the fisheye lens on the market can achieve a large field of view, the existing lens configuration form is difficult to correct the system aberration well, resulting in poor lens imaging quality. In addition, the existing fisheye lens generally has poor color correction, which seriously affects the imaging quality of the lens. Moreover, the existing fisheye lens has a small relative aperture and poor light transmission performance, which cannot adapt to the dark environment at night or in rainy days. In addition, the imaging target surface of the existing fisheye lens is small, which cannot meet the market demand.

[0004] Therefore, how to improve the performance and performance of fisheye lens in the above aspects and provide a fisheye lens with one or more characteristics such as large field of view, high imaging quality, large aperture, small size, large target surface, etc. so as to better meet the high demand of market development has become one of the technical problems to be solved by the technical personnel in the field at present. SUMMARY

[0005] The present application provides a fisheye lens, which can include, in order from the object side to the image side along the optical axis: a first lens with negative refractive power, whose object side is convex and whose image side is concave; a second lens with refractive power; a third lens with refractive power; a fourth lens with refractive power, whose refractive power is opposite in sign to that of the third lens; a fifth lens with positive refractive power, whose object side is convex and whose image side is convex; a sixth lens with positive refractive power, whose object side is convex and whose image side is convex; a seventh lens with negative refractive power, whose object side is concave and whose image side is concave; and an eighth lens with positive refractive power, whose object side is convex and whose image side is convex.

[0006] In one embodiment, the effective focal length f1 of the first lens and the total effective focal length f of the fisheye lens can satisfy: -2.3≤f1 / f≤-1.4.

[0007] In one embodiment, the effective focal length f2 of the second lens and the total effective focal length f of the fisheye lens can satisfy: -4.5≤f2 / f≤9.5.

[0008] In an embodiment, a combined focal length f234 of the second lens, the third lens and the fourth lens and a total effective focal length f of the fisheye lens can satisfy: -23.0≤f234 / f≤45.0.

[0009] In an embodiment, an effective focal length f3 of the third lens and a total effective focal length f of the fisheye lens can satisfy: -2.8≤f3 / f≤3.3.

[0010] In an embodiment, an effective focal length f4 of the fourth lens and a total effective focal length f of the fisheye lens can satisfy: -5.1≤f4 / f≤7.9.

[0011] In an embodiment, an effective focal length f5 of the fifth lens and a total effective focal length f of the fisheye lens can satisfy: 2.0≤f5 / f≤3.6.

[0012] In an embodiment, a combined focal length f67 of the sixth lens and the seventh lens and a total effective focal length f of the fisheye lens can satisfy: -9.2≤f67 / f≤-2.5.

[0013] In an embodiment, an effective focal length f5 of the fifth lens, an effective focal length f6 of the sixth lens and an effective focal length f7 of the seventh lens can satisfy: -1.2≤f5 / f6+f5 / f7≤-0.3.

[0014] In an embodiment, an effective focal length f8 of the eighth lens and a total effective focal length f of the fisheye lens can satisfy: 2.1≤f8 / f≤3.7.

[0015] In an embodiment, a total effective focal length f of the fisheye lens and an entrance pupil diameter ENPD of the fisheye lens can satisfy: 1.70≤f / ENPD≤1.85.

[0016] In an embodiment, a distance BFL on the optical axis from a center of an image side surface of the eighth lens to an imaging surface of the fisheye lens and a distance TTL on the optical axis from a center of an object side surface of the first lens to the imaging surface can satisfy: BFL / TTL≤0.2.

[0017] In an embodiment, the fisheye lens further comprises a stop between the fourth lens and the fifth lens, a distance THI1 on the optical axis from a center of an object side surface of the first lens to the stop and a distance TTL on the optical axis from a center of an object side surface of the first lens to an imaging surface of the fisheye lens can satisfy: 0.4≤THI1 / TTL≤0.6.

[0018] In an embodiment, a distance TTL on the optical axis from a center of an object side surface of the first lens to an imaging surface of the fisheye lens and a total effective focal length f of the fisheye lens can satisfy: 7.8≤TTL / f≤8.8.

[0019] In an embodiment, an effective optical aperture D1 of the first lens and an image height IH of the fisheye lens can satisfy: 1.1≤D1 / IH≤1.5.

[0020] In an embodiment, an effective optical aperture D1 of the first lens and a curvature radius R11 of the object side surface of the first lens can satisfy: 0.4≤D1 / R11≤1.0.

[0021] In an embodiment, a curvature radius R32 of the image side surface of the third lens and a curvature radius R31 of the object side surface of the third lens can satisfy: -77≤R32 / R31≤0.

[0022] In an embodiment, a curvature radius R51 of the object side surface of the fifth lens, a curvature radius R52 of the image side surface of the fifth lens, a curvature radius R61 of the object side surface of the sixth lens, and a curvature radius R62 of the image side surface of the sixth lens can satisfy: │((R51+R52) / (R61+R62)) / ((R51-R52) / (R61-R62))│≤1.0.

[0023] In an embodiment, an Abbe number VD1 of the first lens can satisfy: VD1≤35.

[0024] In an embodiment, an Abbe number VD5 of the fifth lens can satisfy: VD5≥60.

[0025] In an embodiment, a refractive index ND1 of the first lens can satisfy: ND1≥1.80.

[0026] The fisheye lens of the present application adopts eight lenses, and by reasonably setting parameters such as refractive power, surface shape, curvature radius, and Abbe number of each lens, the fisheye lens can have characteristics such as large field of view, high imaging quality, large aperture, and small size, and large target surface. BRIEF DESCRIPTION OF DRAWINGS

[0027] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of the embodiments when read in conjunction with the accompanying drawings. In the drawings:

[0028] Figure 1 is a structure schematic diagram of a fisheye lens according to Embodiment 1 of the present application;

[0029] Figure 2is a structural schematic diagram of a fisheye lens according to Embodiment 2 of the present application;

[0030] Figure 3 is a structural schematic diagram of a fisheye lens according to Embodiment 3 of the present application;

[0031] Figure 4 is a structural schematic diagram of a fisheye lens according to Embodiment 4 of the present application; and

[0032] Figure 5 is a structural schematic diagram of a fisheye lens according to Embodiment 5 of the present application. DETAILED DESCRIPTION

[0033] For the purpose of promoting an understanding of the present application, the present application will be described in greater detail below with reference to the relevant drawings. It should be understood that these detailed description is merely a description of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0034] It should be noted that, in the present specification, the expressions first, second, third, and the like are merely used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, the first lens discussed below can also be referred to as the second lens or the third lens without departing from the teachings of the present application.

[0035] In the drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for the purpose of illustration. Specifically, the shape of the spherical surface or the aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical surface or the aspherical surface is not limited to the shape of the spherical surface or the aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0036] In the present specification, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the imaging side is referred to as the image side surface of the lens.

[0037] It should also be understood that the words "comprise," "comprising," "include," "including," and / or "has," "having," when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when terms such as "at least one of," "one or more of," or "one or more" are used in this specification, these terms are intended to mean that the list of features, elements, and / or components followed by these terms is intended to be inclusive of one, more than one, or all of the listed features, elements, and / or components, and any combination thereof. Furthermore, when describing the embodiments of the present application, the use of "can" means "one or more embodiments of the present application." Also, the use of the term "exemplary" is intended to present an example or an illustration.

[0038] 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 will be further 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 overly literal or overly formal sense unless expressly so defined herein.

[0039] It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0040] The features, principles, and other aspects of the present application are described in detail below.

[0041] In an exemplary embodiment, the fisheye lens includes, for example, eight lenses with optical power, i.e., a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The eight lenses are arranged in order along the optical axis from the object side to the image side.

[0042] In an exemplary embodiment, the first lens can have negative optical power. The first lens can have a convex-concave surface type. The first lens is a meniscus shape with a convex surface facing the object side and has negative optical power, which can effectively play a role in light collection to achieve a large field of view and high resolution. At the same time, the first lens can effectively control the aperture of the optical system to achieve the longitudinal miniaturization of the optical lens.

[0043] In an exemplary embodiment, the second lens can have positive optical power. The second lens can have a concave-convex surface type. The second lens is a positive power lens, which, in cooperation with the first lens having negative optical power, can effectively correct the edge field of view aberration and improve the resolution.

[0044] In an exemplary embodiment, the second lens can have a negative focal power. The second lens can have a convex-concave surface type. The second lens is a negative focal power lens, and the image side is concave, which is beneficial for further collecting light rays so that as many large-angle light rays as possible enter the optical system, effectively improving the illumination of the optical system.

[0045] In an exemplary embodiment, the third lens can have a negative focal power. The third lens can have a concave-concave surface type. The third lens is a negative focal power lens, which effectively diverges light rays, can improve the illumination while meeting the image size requirement.

[0046] In an exemplary embodiment, the third lens can have a positive focal power. The third lens can have a convex-convex surface type. The third lens is a positive focal power lens, which effectively converges light rays, and in cooperation with the negative focal power lenses of the first lens and the second lens, can balance the large field aberration and improve the resolution.

[0047] In an exemplary embodiment, the fourth lens can have a positive focal power. The fourth lens can have a convex-concave surface type, or the fourth lens can have a concave-convex surface type. The fourth lens is a positive focal power lens, which cooperates with the positive focal power lens of the second lens and the negative focal power lens of the third lens, can eliminate chromatic aberration, reduce spherical aberration, and also correct astigmatism and improve the resolution.

[0048] In an exemplary embodiment, the fourth lens can have a negative focal power. The fourth lens can have a concave-convex surface type. The fourth lens is a negative focal power lens, which cooperates with the negative focal power lens of the second lens and the positive focal power lens of the third lens, can eliminate chromatic aberration, reduce spherical aberration, and also correct astigmatism and improve the resolution.

[0049] In an exemplary embodiment, the fifth lens can have a positive focal power. The fifth lens can have a convex-convex surface type. The fifth lens is a positive focal power lens, which can effectively correct the chromatic aberration of the system and play a good balancing role in the high and low temperature of the optical system.

[0050] In an exemplary embodiment, the sixth lens can have a positive focal power. The sixth lens can have a convex-convex surface type.

[0051] In an exemplary embodiment, the seventh lens can have a negative focal power. The seventh lens can have a concave-concave surface type.

[0052] The sixth lens is set as a positive focal power lens, and the seventh lens is set as a negative focal power lens. By cementing the sixth lens and the seventh lens, chromatic aberration can be corrected and the imaging quality can be improved; at the same time, it is beneficial to reduce the system tolerance sensitivity.

[0053] In an exemplary embodiment, the eighth lens can have positive refractive power. The eighth lens can have a convex-convex surface shape. The eighth lens, as a positive refractive power lens, can effectively eliminate aberration and control the exit angle of the chief ray to achieve a large target surface.

[0054] In an exemplary embodiment, the first lens can have negative refractive power, the object side surface thereof can be convex, and the image side surface thereof can be concave; the second lens can have refractive power; the third lens and the fourth lens can have positive and negative refractive power respectively; the fifth lens can have positive refractive power, the object side surface thereof can be convex, and the image side surface thereof can be convex; the sixth lens can have positive refractive power, the object side surface thereof can be convex, and the image side surface thereof can be convex; the seventh lens can have negative refractive power, the object side surface thereof can be concave, and the image side surface thereof can be concave; and the eighth lens can have positive refractive power, the object side surface thereof can be convex, and the image side surface thereof can be convex. Such arrangement of the refractive power and surface shape of each lens included in the fisheye lens of the present application can be beneficial to achieving one or more of the following advantages, such as a large field of view, high imaging quality, a large aperture, a small size, and a large target surface.

[0055] In an exemplary embodiment, the fisheye lens according to the present application can further include a diaphragm, which can be located between the fourth lens and the fifth lens, for example. It should be noted that the location of the diaphragm disclosed herein is merely exemplary and not limiting; in alternative embodiments, the diaphragm can be located at other positions as needed.

[0056] In an exemplary embodiment, the fisheye lens can further include a photosensitive element disposed on the imaging surface. Optionally, the photosensitive element disposed on the imaging surface can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS).

[0057] In an exemplary embodiment, the sixth lens and the seventh lens can be cemented to form a double-cemented lens group. Cementing the sixth lens and the seventh lens can be beneficial to correcting chromatic aberration and improving imaging quality, and can also be beneficial to reducing the sensitivity of system tolerance.

[0058] In an exemplary embodiment, at least one of the lenses included in the fisheye lens can be an aspherical lens. For example, in one embodiment, the second lens, the third lens, the fourth lens, and the eighth lens can be aspherical lenses. For another example, in another embodiment, the second lens, the fourth lens, and the eighth lens can be aspherical lenses.

[0059] In an exemplary embodiment, the first lens to the eighth lens can all be made of glass. Using all-glass material for the first lens to the eighth lens can be beneficial to achieving stable imaging of the lens in harsh environments such as high and low temperatures.

[0060] According to the fisheye lens of the example embodiment of the present application, a large target surface and high illumination performance can be achieved. In the example embodiment, the maximum image height of the lens can reach 8.45 mm, and the illumination can reach 45% or above.

[0061] In the example embodiment, the fisheye lens according to the present application can satisfy -2.3≤f1 / f≤-1.4, where f1 is the effective focal length of the first lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the effective focal length of the first lens to the total effective focal length of the fisheye lens within this range, it is beneficial to make large-angle light rays enter the optical system, and expand the maximum field angle of the optical system.

[0062] In the example embodiment, the fisheye lens according to the present application can satisfy -4.5≤f2 / f≤9.5, where f2 is the effective focal length of the second lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the effective focal length of the second lens to the total effective focal length of the fisheye lens within this range, it is beneficial to make more light rays enter the optical system smoothly, effectively correct the edge field aberration, and improve the resolving power of the lens.

[0063] In the example embodiment, the fisheye lens according to the present application can satisfy -23.0≤f234 / f≤45.0, where f234 is the combined focal length of the second lens, the third lens and the fourth lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the combined focal length of the second lens, the third lens and the fourth lens to the total effective focal length of the fisheye lens within this range, chromatic aberration can be eliminated, spherical aberration can be reduced, and astigmatism can be corrected, thereby improving the resolving power.

[0064] In the example embodiment, the fisheye lens according to the present application can satisfy -2.8≤f3 / f≤3.3, where f3 is the effective focal length of the third lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the effective focal length of the third lens to the total effective focal length of the fisheye lens within this range, chromatic aberration can be eliminated, spherical aberration can be reduced, and astigmatism can be corrected, thereby improving the resolving power.

[0065] In the example embodiment, the fisheye lens according to the present application can satisfy -5.1≤f4 / f≤7.9, where f4 is the effective focal length of the fourth lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the effective focal length of the fourth lens to the total effective focal length of the fisheye lens within this range, chromatic aberration can be eliminated, spherical aberration can be reduced, and astigmatism can be corrected, thereby improving the resolving power.

[0066] In an example embodiment, the fisheye lens according to the present application can satisfy: 2.0≤f5 / f≤3.6, where f5 is the effective focal length of the fifth lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the effective focal length of the fifth lens to the total effective focal length of the fisheye lens to be in this range, the system chromatic aberration can be effectively corrected, and the high and low temperature of the optical system can be well balanced.

[0067] In an example embodiment, the fisheye lens according to the present application can satisfy: -9.2≤f67 / f≤-2.5, where f67 is the combined focal length of the sixth lens and the seventh lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the combined focal length of the sixth lens and the seventh lens to the total effective focal length of the fisheye lens to be in this range, the chromatic aberration can be corrected, the imaging quality can be improved, and the system tolerance sensitivity can be reduced.

[0068] In an example embodiment, the fisheye lens according to the present application can satisfy: -1.2≤f5 / f6+f5 / f7≤-0.3, where f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f7 is the effective focal length of the seventh lens. By controlling the effective focal length of the fifth lens, the effective focal length of the sixth lens, and the effective focal length of the seventh lens to satisfy the condition -1.2≤f5 / f6+f5 / f7≤-0.3, the optical power is reasonably distributed, the imaging quality is improved, and the system tolerance sensitivity is reduced.

[0069] In an example embodiment, the fisheye lens according to the present application can satisfy: 2.1≤f8 / f≤3.7, where f8 is the effective focal length of the eighth lens, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the effective focal length of the eighth lens to the total effective focal length of the fisheye lens to be in this range, the chief ray exit angle can be controlled, high-illumination large target surface can be achieved, the maximum image height of the lens can be up to 8.45mm, and the illumination can be ≥45%.

[0070] In an example embodiment, the fisheye lens according to the present application can satisfy: 1.70≤f / ENPD≤1.85, where f is the total effective focal length of the fisheye lens, and ENPD is the entrance pupil diameter of the fisheye lens. By controlling the ratio of the total effective focal length of the lens to the entrance pupil diameter of the lens to be in this range, a large aperture of the fisheye lens can be achieved.

[0071] In an exemplary embodiment, the fisheye lens according to the present application can satisfy: BFL / TTL≤0.2, where BFL is the distance from the center of the image side surface of the eighth lens to the imaging surface of the fisheye lens on the optical axis, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface on the optical axis. By controlling the ratio of the distance from the center of the image side surface of the eighth lens to the imaging surface of the fisheye lens on the optical axis to the distance from the center of the object side surface of the first lens to the imaging surface on the optical axis to be within this range, the miniaturization of the fisheye lens can be facilitated.

[0072] In an exemplary embodiment, the fisheye lens, for example, includes a diaphragm between the fourth lens and the fifth lens, and the fisheye lens according to the present application can satisfy: 0.4≤THI1 / TTL≤0.6, where THI1 is the distance from the center of the object side surface of the first lens to the diaphragm on the optical axis, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the fisheye lens on the optical axis. By controlling the ratio of the distance from the center of the object side surface of the first lens to the diaphragm on the optical axis to the distance from the center of the object side surface of the first lens to the imaging surface of the fisheye lens on the optical axis to be within this range, the miniaturization of the fisheye lens can be facilitated.

[0073] In an exemplary embodiment, the fisheye lens according to the present application can satisfy: 7.8≤TTL / f≤8.8, where TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the fisheye lens on the optical axis, and f is the total effective focal length of the fisheye lens. By controlling the ratio of the distance from the center of the object side surface of the first lens to the imaging surface of the fisheye lens on the optical axis to the total effective focal length of the fisheye lens to be within this range, the miniaturization of the lens can be facilitated.

[0074] In an exemplary embodiment, the fisheye lens according to the present application can satisfy: 1.1≤D1 / IH≤1.5, where D1 is the effective optical aperture of the first lens, and IH is the image height of the fisheye lens. By controlling the ratio of the effective optical aperture of the first lens to the image height of the fisheye lens to be within this range, the miniaturization of the lens can be facilitated.

[0075] In an exemplary embodiment, the fisheye lens according to the present application can satisfy: 0.4≤D1 / R11≤1.0, where D1 is the effective optical aperture of the first lens, and R11 is the radius of curvature of the object side surface of the first lens. By controlling the ratio of the effective optical aperture of the first lens to the radius of curvature of the object side surface of the first lens to be within this range, the miniaturization of the lens can be facilitated.

[0076] In an exemplary embodiment, the fisheye lens according to the present application can satisfy: -77≤R32 / R31≤0, wherein R32 is the curvature radius of the image side surface of the third lens, and R31 is the curvature radius of the object side surface of the third lens. By controlling the ratio of the curvature radius of the image side surface of the third lens to the curvature radius of the object side surface of the third lens to be within the range, the light ray path can be reasonably distributed, and a large target surface can be ensured while the resolution is improved.

[0077] In an exemplary embodiment, the fisheye lens according to the present application can satisfy: │((R51+R52) / (R61+R62)) / ((R51-R52) / (R61-R62))│≤1.0, wherein R51 is the curvature radius of the object side surface of the fifth lens, R52 is the curvature radius of the image side surface of the fifth lens, R61 is the curvature radius of the object side surface of the sixth lens, and R62 is the curvature radius of the image side surface of the sixth lens. By controlling the curvature radius of the object side surface of the fifth lens, the curvature radius of the image side surface of the fifth lens, the curvature radius of the object side surface of the sixth lens, and the curvature radius of the image side surface of the sixth lens to satisfy the condition formula │((R51+R52) / (R61+R62)) / ((R51-R52) / (R61-R62))│≤1.0, the deviation of the incidence angle and the exit angle of light rays of different fields of view can be reduced, the light rays can be smoothly transitioned, the tolerance sensitivity can be reduced, and the lens yield can be improved.

[0078] In an exemplary embodiment, the Abbe number VD1 of the first lens of the fisheye lens according to the present application can satisfy: VD1≤35. By controlling the Abbe number of the first lens to be within the range, the system chromatic aberration can be balanced, and the resolving power can be improved.

[0079] In an exemplary embodiment, the Abbe number VD5 of the fifth lens of the fisheye lens according to the present application can satisfy: VD5≥60. By controlling the Abbe number of the fifth lens to be within the range, for example, using an anomalous dispersion material, the system high and low temperature performance can be balanced while correcting chromatic aberration and improving resolution.

[0080] In an exemplary embodiment, the refractive index ND1 of the first lens of the fisheye lens according to the present application can satisfy: ND1≥1.80. By controlling the refractive index of the first lens to be within the range, for example, using a material with ND≥1.80, the lens aperture can be effectively limited, miniaturization can be achieved, and large-angle light rays can be incident into the optical system, thereby expanding the maximum field of view angle of the optical system.

[0081] In an exemplary embodiment, as needed, the fisheye lens according to the present application can further include a filter and / or a protective glass disposed between the eighth lens and the imaging surface. The filter can filter light rays with a specific wavelength, and the protective glass can prevent the image side elements (for example, a chip) of the fisheye lens from being damaged.

[0082] The fisheye lens according to the embodiments of the present application can adopt multiple lenses, for example, eight lenses as described above. By reasonably setting the parameters of the refractive power, surface shape, radius of curvature, and Abbe number of each lens, and by reasonably setting the cemented lens group, a fisheye lens with the characteristics of large field of view, high imaging quality, large aperture, and the like is provided, while meeting the characteristics of small size and large target surface.

[0083] However, those skilled in the art should understand that the number of lenses constituting the lens can be changed without departing from the technical solutions claimed by the present application, to obtain the various results and advantages described in the present specification. For example, although eight lenses are described as an example in the embodiments, the fisheye lens is not limited to including eight lenses. If necessary, the fisheye lens can also include other numbers of lenses. Specific embodiments of the fisheye lens applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

[0084] Example 1

[0085] Figure 1 is a structural schematic diagram of a fisheye lens according to Embodiment 1 of the present application, and the fisheye lens according to Embodiment 1 of the present application is described below with reference to Figure 1

[0086] As shown in Figure 1 , the fisheye lens sequentially includes, along the optical axis from the object side to the image side: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter and / or a protective glass CG, and an imaging surface IMA. Among them, the sixth lens L6 and the seventh lens L7 are cemented to form a double-cemented lens group.

[0087] In this embodiment, the first lens L1 has a negative refractive power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface. The second lens L2 has a positive refractive power, the object side surface S3 is a concave surface, and the image side surface S4 is a convex surface. The third lens L3 has a negative refractive power, the object side surface S5 is a concave surface, and the image side surface S6 is a concave surface. The fourth lens L4 has a positive refractive power, the object side surface S7 is a convex surface, and the image side surface S8 is a concave surface. The fifth lens L5 has a positive refractive power, the object side surface S10 is a convex surface, and the image side surface S11 is a convex surface. The sixth lens L6 has a positive refractive power, the object side surface S12 is a convex surface, and the image side surface S13 is a convex surface. The seventh lens L7 has a negative refractive power, the object side surface S13 is a concave surface, and the image side surface S14 is a concave surface. The eighth lens L8 has a positive refractive power, the object side surface S15 is a convex surface, and the image side surface S16 is a convex surface.

[0088] In this embodiment, the stop STO of the fisheye lens is arranged between the fourth lens L4 and the fifth lens L5. ​

[0089] In this embodiment, the filter and / or the protection glass CG located between the eighth lens L8 and the imaging surface have an object side S17 and an image side S18. The light from the object sequentially passes through each surface S1 to S18 and is finally imaged on the imaging surface, wherein an image sensing chip IMA can be provided at the imaging surface.

[0090] Table 1 shows the radius of curvature R, the thickness d / distance T, the refractive index N and the Abbe number Vd of each lens of the fisheye lens of embodiment 1. Wherein, regarding the "thickness d / distance T", it should be understood that the thickness d / distance T of the row where S1 is located is the central thickness of the first lens L1, the thickness d / distance T of the row where S2 is located is the air gap distance between the first lens L1 and the second lens L2, the thickness d / distance T of the row where S3 is located is the central thickness of the second lens L2, and so on.

[0091]

[0092] Table 1

[0093] In this embodiment, the maximum field of view FOV of the fisheye lens = 160°, and the aperture value FNO of the fisheye lens = 1.80.

[0094] In embodiment 1, the object side and the image side of the second lens L2, the third lens L3, the fourth lens L4 and the eighth lens L8 are all aspherical surfaces, and the surface type x of each aspherical surface can be defined by, but not limited to, the following aspherical surface formula:

[0095]

[0096] Wherein, x is the distance sag of the aspherical surface at a height h along the optical axis direction from the vertex of the aspherical surface; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the inverse 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 below gives the conic coefficient k and the high-order term coefficients A4, A6, A8, A10 of each aspherical surface S3 to S8, S15 and S16 that can be used in embodiment 1. 10 and A 12 .

[0097] Face number k A4 A6 A8 A10 A12 S3 1.72 9.39E-03 -7.89E-04 9.87E-05 -6.28E-06 4.27E-07 S4 0.40 7.07E-03 -1.31E-03 2.38E-04 -2.55E-05 1.66E-06 S5 -1.91 1.13E-03 -1.33E-03 3.77E-04 -4.40E-05 2.28E-06 S6 27.23 1.47E-03 -3.55E-04 -1.02E-04 2.06E-05 -1.71E-06 S7 -0.14 8.71E-04 -4.04E-04 2.37E-05 1.65E-06 -2.56E-07 S8 0.00 4.65E-03 1.92E-04 -2.67E-05 8.94E-06 -9.36E-07 S15 -1.34 2.42E-03 1.24E-04 -8.20E-06 6.78E-07 -1.61E-08 S16 -20.37 8.66E-04 6.48E-04 -5.03E-05 3.09E-06 -7.96E-08

[0098] Table 2

[0099] Example 2

[0100] Figure 2 The structure schematic diagram of the fisheye lens according to embodiment 2 of the present application is shown, and the following refers to Figure 2An fisheye lens according to Embodiment 2 of the present application is described. In this and the following embodiments, the description similar to Embodiment 1 will be omitted for brevity.

[0101] As shown in FIG. 2, the fisheye lens comprises, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter and / or a cover glass CG, and an imaging surface IMA. The sixth lens L6 and the seventh lens L7 are cemented to form a double cemented lens group. Figure 2

[0102] In this embodiment, the first lens L1 has a negative refractive power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface. The second lens L2 has a positive refractive power, the object side surface S3 is a concave surface, and the image side surface S4 is a convex surface. The third lens L3 has a negative refractive power, the object side surface S5 is a concave surface, and the image side surface S6 is a concave surface. The fourth lens L4 has a positive refractive power, the object side surface S7 is a concave surface, and the image side surface S8 is a convex surface. The fifth lens L5 has a positive refractive power, the object side surface S10 is a convex surface, and the image side surface S11 is a convex surface. The sixth lens L6 has a positive refractive power, the object side surface S12 is a convex surface, and the image side surface S13 is a convex surface. The seventh lens L7 has a negative refractive power, the object side surface S13 is a concave surface, and the image side surface S14 is a concave surface. The eighth lens L8 has a positive refractive power, the object side surface S15 is a convex surface, and the image side surface S16 is a convex surface.

[0103] In this embodiment, the stop STO of the fisheye lens is arranged between the fourth lens L4 and the fifth lens L5.

[0104] In this embodiment, the filter and / or the cover glass CG between the eighth lens L8 and the imaging surface has an object side surface S17 and an image side surface S18. Light from the object passes through the surfaces S1 to S18 in order and is finally imaged on the imaging surface, wherein an image sensor chip IMA can be arranged at the imaging surface.

[0105] Table 3 shows the radius of curvature R, the thickness d / distance T, the refractive index N, and the Abbe number Vd of each lens of the fisheye lens of Embodiment 2.

[0106]

[0107] Table 3

[0108] In this embodiment, the maximum field of view FOV of the fisheye lens is 160°, and the aperture value FNO of the fisheye lens is 1.73.

[0109] ​In this embodiment, the object-side and image-side surfaces of the second lens L2, the third lens L3, the fourth lens L4, and the eighth lens L8 are all aspherical surfaces, and the surface shape of each aspherical surface can be defined by formula (1) given in Embodiment 1 above. Table 4 gives the conic coefficient k and higher-order coefficients A4, A6, A8, and A6 of each aspherical mirror surface S3 to S8, S15, and S16 that can be used in this embodiment. 10 A 12 and A 14 .

[0110] Face number k A4 A6 A8 A10 A12 A14 S3 0.89 2.06E-03 -1.07E-04 -1.03E-05 2.22E-06 -8.63E-08 -7.95E-10 S4 -0.27 7.60E-03 -1.16E-03 1.63E-04 -1.32E-05 6.68E-07 -1.17E-09 S5 -0.01 1.14E-02 -2.17E-03 3.57E-04 -2.39E-05 7.60E-07 -9.99E-10 S6 0.00 1.45E-03 4.64E-03 -1.24E-03 1.52E-04 -7.89E-06 -4.36E-09 S7 0.00 3.45E-03 2.70E-03 -7.68E-04 9.46E-05 -4.82E-06 -1.05E-09 S8 2.45 1.37E-03 2.99E-04 -8.56E-05 1.07E-05 -5.58E-07 -1.24E-10 S15 -0.03 -1.88E-03 1.06E-04 -7.39E-06 6.97E-07 3.65E-10 0.00E+00 S16 0.41 2.73E-03 -1.32E-04 3.79E-05 -3.26E-06 1.50E-07 0.00E+00

[0111] Table 4

[0112] Example 3

[0113] Figure 3 A schematic diagram of the structure of a fisheye lens according to Embodiment 3 of this application is shown below, with reference to the following. Figure 3 The fisheye lens according to Embodiment 3 of this application is described.

[0114] like Figure 3 As shown, the fisheye lens, along the optical axis from the object side to the image side, includes, in sequence: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture stop STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter and / or protective glass CG, and an imaging plane IMA. The sixth lens L6 and the seventh lens L7 are cemented together to form a cemented doublet lens group.

[0115] In this embodiment, the first lens L1 has negative optical power, its object-side surface S1 is convex, and its image-side surface S2 is concave. The second lens L2 has positive optical power, its object-side surface S3 is concave, and its image-side surface S4 is convex. The third lens L3 has negative optical power, its object-side surface S5 is concave, and its image-side surface S6 is concave. The fourth lens L4 has positive optical power, its object-side surface S7 is concave, and its image-side surface S8 is convex. The fifth lens L5 has positive optical power, its object-side surface S10 is convex, and its image-side surface S11 is convex. The sixth lens L6 has positive optical power, its object-side surface S12 is convex, and its image-side surface S13 is convex. The seventh lens L7 has negative optical power, its object-side surface S13 is concave, and its image-side surface S14 is concave. The eighth lens L8 has positive optical power, its object-side surface S15 is convex, and its image-side surface S16 is convex.

[0116] In this embodiment, the aperture stop STO of the fisheye lens is positioned between the fourth lens L4 and the fifth lens L5.

[0117] In this embodiment, the filter and / or the protection glass CG located between the eighth lens L8 and the imaging surface has an object side surface S17 and an image side surface S18. The light from the object sequentially passes through each surface S1 to S18 and is finally imaged on the imaging surface, wherein an image sensing chip IMA can be provided at the imaging surface.

[0118] Table 5 shows the radius of curvature R, the thickness d / distance T, the refractive index N and the Abbe number Vd of each lens of the fisheye lens of embodiment 3.

[0119]

[0120]

[0121] Table 5

[0122] In this embodiment, the maximum field of view FOV of the fisheye lens = 160°, and the aperture value FNO of the fisheye lens = 1.73.

[0123] In this embodiment, the object side surface and the image side surface of the second lens L2, the third lens L3, the fourth lens L4 and the eighth lens L8 are aspherical surfaces, each of which can be defined by the formula (1) given in embodiment 1 above. Table 6 gives the conic constant k and the high order term coefficients A4, A6, A8, A10 and A12 of each aspherical surface S3 to S8, S15 and S16 which can be used in this embodiment. 10 and A 12 .

[0124] Face number k A4 A6 A8 A10 A12 S3 -0.51 2.12E-03 -2.26E-04 1.95E-05 -9.86E-07 2.46E-08 S4 -0.15 7.43E-03 -1.28E-03 2.23E-04 -2.03E-05 7.41E-07 S5 -0.28 8.31E-03 -1.47E-03 3.07E-04 -3.48E-05 1.55E-06 S6 0.00 2.80E-03 4.86E-03 -1.27E-03 1.55E-04 -8.21E-06 S7 0.00 3.91E-03 2.32E-03 -7.24E-04 9.71E-05 5.48E-06 S8 5.89 1.25E-03 1.91E-04 -7.26E-05 9.97E-06 -5.37E-07 S15 0.12 -1.39E-03 1.64E-04 -8.07E-06 1.27E-06 -5.03E-08 S16 -0.85 2.80E-03 -1.15E-04 4.33E-05 -3.64E-06 1.77E-07

[0125] Table 6

[0126] Example 4

[0127] Figure 4 A structure schematic diagram of a fisheye lens according to embodiment 4 of the present application is shown, and the fisheye lens according to embodiment 4 of the present application is described below with reference to Figure 4

[0128] As shown in Figure 4 , the fisheye lens sequentially comprises, along the optical axis from the object side to the image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter and / or a protection glass CG and an imaging surface IMA. Among them, the sixth lens L6 and the seventh lens L7 are cemented to form a double cemented lens group.

[0129] ​In this embodiment, the first lens L1 has a negative focal power, the object side surface S1 is convex, and the image side surface S2 is concave. The second lens L2 has a negative focal power, the object side surface S3 is convex, and the image side surface S4 is concave. The third lens L3 has a positive focal power, the object side surface S5 is convex, and the image side surface S6 is convex. The fourth lens L4 has a negative focal power, the object side surface S7 is concave, and the image side surface S8 is convex. The fifth lens L5 has a positive focal power, the object side surface S10 is convex, and the image side surface S11 is convex. The sixth lens L6 has a positive focal power, the object side surface S12 is convex, and the image side surface S13 is convex. The seventh lens L7 has a negative focal power, the object side surface S13 is concave, and the image side surface S14 is concave. The eighth lens L8 has a positive focal power, the object side surface S15 is convex, and the image side surface S16 is convex.

[0130] In this embodiment, the stop STO of the fisheye lens is arranged between the fourth lens L4 and the fifth lens L5.

[0131] In this embodiment, the filter and / or the protective glass CG between the eighth lens L8 and the imaging surface have an object side surface S17 and an image side surface S18. The light from the object sequentially passes through the surfaces S1 to S18 and is finally imaged on the imaging surface, wherein an image sensor chip IMA can be arranged at the imaging surface.

[0132] Table 7 shows the radius of curvature R, the thickness d / distance T, the refractive index N, and the Abbe number Vd of each lens of the fisheye lens of embodiment 4.

[0133]

[0134] Table 7

[0135] In this embodiment, the maximum field of view FOV of the fisheye lens is 160°, and the aperture value FNO of the fisheye lens is 1.80.

[0136] In this embodiment, the object side surface and the image side surface of the second lens L2, the fourth lens L4, and the eighth lens L8 are aspherical surfaces, and each aspherical surface can be defined by the formula (1) given in embodiment 1 above. Table 8 gives the conic coefficients k and the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, A30, A32, A34, A36, A38, A40, A42, A44, A46, A48, A50, A52, A54, A56, A58, A60, A62, A64, A66, A68, A70, A72, A74, A76, A78, A80, A82, A84, A86, A88, A90, A92, A94, A96, A98, and A100 of the aspherical surfaces S3, S4, S7, S8, S15, and S16 that can be used in this embodiment. 10 12 .

[0137] Face number k A4 A6 A8 A10 A12 S3 -6.62 1.06E-02 -9.20E-04 8.31E-05 -5.56E-06 1.18E-07 S4 0.35 1.06E-02 -1.11E-03 1.11E-04 -1.44E-05 2.12E-08 S7 -0.28 1.06E-02 -4.55E-05 -1.49E-05 5.62E-06 -2.62E-07 S8 -0.56 6.92E-03 -3.59E-05 3.81E-05 -3.52E-06 3.79E-07 S15 0.73 5.99E-04 1.65E-04 -1.88E-05 1.07E-06 -2.86E-08 S16 -9.07 -8.39E-04 3.64E-04 -2.09E-05 9.09E-07 -2.82E-08

[0138] Table 8

[0139] Example 5

[0140] Figure 5 ​A structural schematic of the fisheye lens according to Embodiment 5 of the present application is shown, and the following refers to Figure 5 A fisheye lens according to Embodiment 5 of the present application is described.

[0141] As shown in Figure 5 the fisheye lens includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a stop STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter and / or a cover glass CG, and an imaging surface IMA. The sixth lens L6 and the seventh lens L7 are cemented to form a double cemented lens group.

[0142] In this embodiment, the first lens L1 has a negative refractive power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface. The second lens L2 has a negative refractive power, the object side surface S3 is a convex surface, and the image side surface S4 is a concave surface. The third lens L3 has a positive refractive power, the object side surface S5 is a convex surface, and the image side surface S6 is a convex surface. The fourth lens L4 has a negative refractive power, the object side surface S7 is a concave surface, and the image side surface S8 is a convex surface. The fifth lens L5 has a positive refractive power, the object side surface S10 is a convex surface, and the image side surface S11 is a convex surface. The sixth lens L6 has a positive refractive power, the object side surface S12 is a convex surface, and the image side surface S13 is a convex surface. The seventh lens L7 has a negative refractive power, the object side surface S13 is a concave surface, and the image side surface S14 is a concave surface. The eighth lens L8 has a positive refractive power, the object side surface S15 is a convex surface, and the image side surface S16 is a convex surface.

[0143] In this embodiment, the stop STO of the fisheye lens is arranged between the fourth lens L4 and the fifth lens L5.

[0144] In this embodiment, the filter and / or the cover glass CG between the eighth lens L8 and the imaging surface has an object side surface S17 and an image side surface S18. Light from an object passes through the surfaces S1 to S18 in order and is finally imaged on the imaging surface, wherein an image sensor chip IMA can be arranged at the imaging surface.

[0145] Table 9 shows the curvature radius R, the thickness d / distance T, the refractive index N, and the Abbe number Vd of each lens of the fisheye lens of Embodiment 5.

[0146]

[0147] Table 9

[0148] In this embodiment, the fisheye lens has a maximum field of view FOV = 160°, and the aperture value FNO of the fisheye lens is 1.80.

[0149] In this embodiment, the object-side and image-side surfaces of the second lens L2, the fourth lens L4, and the eighth lens L8 are all aspherical surfaces, and the surface shape of each aspherical surface can be defined by formula (1) given in Embodiment 1 above. Table 10 gives the conic coefficient k and higher-order coefficients A4, A6, A8, and A6 of each aspherical mirror surface S3, S4, S7, S8, S15, and S16 that can be used in this embodiment. 10 and A 12 .

[0150] Face number k A4 A6 A8 A10 A12 S3 -0.71 1.03E-02 -9.34E-04 1.01E-04 -8.31E-06 2.24E-07 S4 -0.06 1.32E-02 -1.51E-03 2.80E-04 -4.63E-05 2.15E-06 S7 -0.69 1.29E-02 -3.76E-04 2.83E-05 -2.00E-06 2.01E-07 S8 -2.79 7.82E-03 -1.94E-05 1.49E-05 -2.34E-06 3.75E-07 S15 1.46 1.61E-03 1.49E-04 -1.79E-05 1.06E-06 -2.48E-08 S16 -29.59 5.37E-04 6.06E-04 -5.19E-05 2.42E-06 -5.33E-08

[0151] Table 10 summarizes that Examples 1 to 5 respectively satisfy the relationships shown in Table 11 below.

[0152] Conditional expression\Example Example 1 Example 2 Example 3 Example 4 Example 5 f1 / f -1.63 -1.60 -1.89 -1.93 -2.00 f2 / f 9.09 3.45 3.11 -3.38 -4.18 f234 / f 14.99 8.68 44.26 -22.22 -10.28 f3 / f -1.80 -2.40 -2.53 2.32 3.20 f4 / f 2.08 4.21 7.57 -4.33 -4.91 f5 / f 2.56 3.45 2.65 2.17 2.21 f67 / f -8.95 -5.83 -4.24 -3.44 -5.50 f5 / f6+f5 / f7 -0.40 -1.10 -1.03 -0.82 -0.60 f8 / f 3.49 2.56 2.64 2.23 2.63 f / ENPD 1.80 1.73 1.73 1.80 1.80 BFL / TTL 0.14 0.17 0.13 0.15 0.14 THI1 / TTL 0.45 0.43 0.42 0.41 0.44 TTL / f 8.42 8.23 8.22 8.59 8.68 D1 / IH 1.19 1.18 1.30 1.28 1.37 D1 / R11 0.83 0.88 0.75 0.58 0.53 R32 / R31 -5.13 -13.85 -76.73 -0.47 -0.07 |((R51+R52) / (R61+R62)) / ((R51-R52) / (R61-R62))| 0.37 0.75 0.90 0.33 0.09 VD1 31.32 28.32 25.48 31.32 31.32 VD5 90.19 94.52 81.61 68.62 63.41 ND1 1.90 2.00 1.81 1.90 1.90

[0153] Table 11

[0154] This application also provides an electronic device that may include a fisheye lens according to the above embodiments of this application and an imaging element for converting the optical image formed by the fisheye lens into an electrical signal.

[0155] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A fisheye lens characterized by comprising: In order from the object side to the image side along the optical axis, the fisheye lens comprises: a first lens with negative refractive power, the object side surface of which is convex, and the image side surface of which is concave; a second lens with refractive power; a third lens with refractive power; a fourth lens with refractive power, the refractive power of which is opposite in sign to the refractive power of the third lens; a fifth lens with positive refractive power, the object side surface of which is convex, and the image side surface of which is convex; a sixth lens with positive refractive power, the object side surface of which is convex, and the image side surface of which is convex; a seventh lens with negative refractive power, the object side surface of which is concave, and the image side surface of which is concave; and an eighth lens with positive refractive power, the object side surface of which is convex, and the image side surface of which is convex; the number of lenses with refractive power in the fisheye lens is eight; and the effective optical aperture D1 of the first lens and the image height IH of the fisheye lens satisfy: 1.1≤D1 / IH≤1.

5.

2. The fisheye lens according to claim 1, characterized by the effective focal length f1 of the first lens and the total effective focal length f of the fisheye lens satisfy: -2.3≤f1 / f≤-1.

4.

3. The fisheye lens according to claim 1, characterized by the effective focal length f2 of the second lens and the total effective focal length f of the fisheye lens satisfy: -4.5≤f2 / f≤9.

5.

4. The fisheye lens according to claim 1, characterized by the combined focal length f234 of the second lens, the third lens and the fourth lens and the total effective focal length f of the fisheye lens satisfy: -23.0≤f234 / f≤45.

0.

5. The fisheye lens according to claim 1, wherein the effective focal length f3 of the third lens and the total effective focal length f of the fisheye lens satisfy: -2.8≤f3 / f≤3.

3.

6. The fisheye lens according to claim 1, wherein the effective focal length f4 of the fourth lens and the total effective focal length f of the fisheye lens satisfy: -5.1≤f4 / f≤7.

9.

7. The fisheye lens according to claim 1, wherein the effective focal length f5 of the fifth lens and the total effective focal length f of the fisheye lens satisfy: 2.0≤f5 / f≤3.

6.

8. The fisheye lens according to claim 1, wherein the combined focal length f67 of the sixth lens and the seventh lens and the total effective focal length f of the fisheye lens satisfy: -9.2≤f67 / f≤-2.

5.

9. The fisheye lens of claim 1, wherein, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens and the effective focal length f7 of the seventh lens satisfy: -1.2≤f5 / f6+f5 / f7≤-0.

3.

10. The fisheye lens of claim 1, wherein, the effective focal length f8 of the eighth lens and the total effective focal length f of the fisheye lens satisfy: 2.1≤f8 / f≤3.

7.

11. The fisheye lens according to any one of claims 1 to 10, characterized in that, the total effective focal length f of the fisheye lens and the entrance pupil diameter ENPD of the fisheye lens satisfy: 1.70≤f / ENPD≤1.

85.

12. The fisheye lens according to any one of claims 1 to 10, characterized in that, the distance BFL from the center of the image side surface of the eighth lens to the imaging surface of the fisheye lens on the optical axis and the distance TTL from the center of the object side surface of the first lens to the imaging surface on the optical axis satisfy: BFL / TTL≤0.

2.

13. The fisheye lens according to any one of claims 1 to 10, characterized in that, the fisheye lens further comprises a diaphragm between the fourth lens and the fifth lens, the distance THI1 from the center of the object side surface of the first lens to the diaphragm on the optical axis and the distance TTL from the center of the object side surface of the first lens to the imaging surface of the fisheye lens on the optical axis satisfy: 0.4≤THI1 / TTL≤0.

6.

14. The fisheye lens according to any one of claims 1 to 10, characterized by A distance TTL on the optical axis from a center of an object side surface of the first lens to an imaging surface of the fisheye lens satisfies: 7.8≤TTL / f≤8.

8.

15. The fisheye lens according to any one of claims 1 to 10, characterized in that, An effective optical aperture D1 of the first lens and a curvature radius R11 of the object side surface of the first lens satisfy: 0.4≤D1 / R11≤1.

0.

16. The fisheye lens according to any one of claims 1 to 10, characterized by A curvature radius R32 of the image side surface of the third lens and a curvature radius R31 of the object side surface of the third lens satisfy: -77≤R32 / R31≤0.

17. The fisheye lens according to any one of claims 1 to 10, characterized by A curvature radius R51 of the object side surface of the fifth lens, a curvature radius R52 of the image side surface of the fifth lens, a curvature radius R61 of the object side surface of the sixth lens, and a curvature radius R62 of the image side surface of the sixth lens satisfy: │((R51+R52) / (R61+R62)) / ((R51-R52) / (R61-R62))│≤1.

0.

18. The fisheye lens according to any one of claims 1 to 10, characterized by An Abbe number VD1 of the first lens satisfies: VD1≤35.

19. The fisheye lens according to any one of claims 1 to 10, characterized by An Abbe number VD5 of the fifth lens satisfies: VD5≥60.

20. The fisheye lens according to any one of claims 1 to 10, characterized by A refractive index ND1 of the first lens satisfies: ND1≥1.

80.

21. The fisheye lens of claim 1, wherein, The fisheye lens further comprises a diaphragm between the fourth lens and the fifth lens. The fisheye lens satisfies at least one of the following: -2.00≤f1 / f≤-1.60; -4.18≤f2 / f≤9.09; -22.22≤f234 / f≤44.26; -2.53≤f3 / f≤3.20; -4.91≤f4 / f≤7.57; 2.17≤f5 / f≤3.45; -8.95≤f67 / f≤-3.44; -1.10≤f5 / f6+f5 / f7≤-0.40; 2.23≤f8 / f≤3.49; 1.70≤f / ENPD≤1.80; 0.13≤BFL / TTL≤0.2; 0.4≤THI1 / TTL≤0.45; 8.22≤TTL / f≤8.68; 1.18≤D1 / IH≤1.37; 0.53≤D1 / R11≤0.88; -76.73≤R32 / R31≤-0.07; 0.09≤│((R51+R52) / (R61+R62)) / ((R51-R52) / (R61-R62))│≤0.90; 25.48≤VD1≤31.32; 94.52≥VD5≥63.41; 2.00≥ND1≥1.80; Wherein, f is the total effective focal length of the fisheye lens, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third 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, f234 is the combined focal length of the third lens and the fourth lens, f67 is the combined focal length of the sixth lens and the seventh lens, ENPD is the entrance pupil diameter of the fisheye lens, BFL is the distance from the center of the image side surface of the eighth lens to the imaging surface of the fisheye lens on the optical axis, TTL is the distance from the center of the object side surface of the first lens to the imaging surface on the optical axis, THI1 is the distance from the center of the object side surface of the first lens to the diaphragm on the optical axis, R11 is the curvature radius of the object side surface of the first lens, R32 is the curvature radius of the image side surface of the third lens, R31 is the curvature radius of the object side surface of the third lens, R51 is the curvature radius of the object side surface of the fifth lens, R52 is the curvature radius of the image side surface of the fifth lens, R61 is the curvature radius of the object side surface of the sixth lens, R62 is the curvature radius of the image side surface of the sixth lens, VD1 is the Abbe number of the first lens, VD5 is the Abbe number of the fifth lens, ND1 is the refractive index of the first lens.

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