A fisheye lens

Abstract

The application discloses a fisheye imaging 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 image side of which is concave; a second lens with refractive power; a third lens with positive refractive power, the object side of which is convex; a diaphragm; a fourth lens with positive refractive power; a fifth lens with refractive power; and a sixth lens with positive refractive power. The effective focal length f1 of the first lens and half of the maximum field angle Semi-FOV of the fisheye imaging lens satisfy 0.9mm < f1 / TAN(Semi-FOV) < 1.6mm. By controlling the ratio of the focal length and the field angle, a large angle resolution can be realized, and a wider field angle can be realized in the same focal length section. The design of the refractive power and shape is stable in structure, the assembly structure is stable during installation, and the imaging quality is high. By controlling the ratio of the refractive index between the lenses, the edge light is smoothly transitioned, and the performance of the edge field is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fisheye imaging lens, in particular to a fisheye imaging lens comprising six lenses. BACKGROUND

[0002] With the development of camera lens industry, the requirement for the imaging quality of lens in extremely low light environment is higher and higher, not only the picture needs to be bright, but also needs to have high definition. The picture taken by the lens used in the prior art is dark, has large noise and low recognition in extremely dark environment, which cannot meet the market demand. The existing fisheye imaging lens also has the problem of high and low temperature non-afocal, and the performance and cost are difficult to balance.

[0003] The present application provides a fisheye lens with good imaging quality, high and low temperature afocal, and ultra-wide angle characteristics, which is suitable for products with demand for fisheye lens.

[0004] APPLICATION CONTENT

[0005] The present application aims to provide a fisheye imaging lens composed of six lenses, which has the characteristics of high and low temperature afocal and ultra-wide angle, and is suitable for product demand for fisheye lens.

[0006] The present application provides a fisheye imaging lens, which comprises, in order from the object side to the image side along the optical axis: a first lens with negative refractive power, the image side of which is concave; a second lens with refractive power; a third lens with positive refractive power, the object side of which is convex; a stop; a fourth lens with positive refractive power; a fifth lens with refractive power; and a sixth lens with positive refractive power.

[0007] Wherein, the effective focal length f1 of the first lens and half of the maximum field angle of view Semi-FOV of the fisheye imaging lens satisfy: 0.9mm < f1 / TAN(Semi-FOV) < 1.6mm.

[0008] According to one embodiment of the present application, the distance SD of the stop to the image side of the sixth lens on the optical axis and the distance TD of the object side of the first lens to the image side of the sixth lens on the optical axis satisfy: 0.2 < SD / TD < 0.4.

[0009] According to one embodiment of the present application, the effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens satisfy: 1.3 < f3 / f4 < 4.3.

[0010] According to one embodiment of the present application, the effective focal length f1 of the first lens and the effective focal length f6 of the sixth lens satisfy: -2.0 < f1 / f6 < -1.2.

[0011] According to an embodiment of the present application, a center thickness CT3 of the third lens on the optical axis, a center thickness CT6 of the sixth lens on the optical axis, and an effective focal length f of the fisheye imaging lens satisfy: 0.7 < (CT3-CT6) / f < 2.

[0012] According to an embodiment of the present application, a center thickness CT2 of the second lens on the optical axis and an edge thickness ET2 of the second lens satisfy: 0.3 < CT2 / ET2 < 0.5.

[0013] According to an embodiment of the present application, a distance TTL of the fisheye imaging lens from the object side surface of the first lens to the image plane on the optical axis, a center thickness CT3 of the third lens on the optical axis, and a center thickness CT4 of the fourth lens on the optical axis satisfy: 2.8 < TTL / (CT3+CT4) < 3.8.

[0014] According to an embodiment of the present application, an air gap thickness T34 of the third lens and the fourth lens on the optical axis and an air gap thickness T12 of the first lens and the second lens on the optical axis satisfy: 0 < Sin(0.5 x Semi-FOV) x T34 / T12 <= 0.2.

[0015] According to an embodiment of the present application, a radius of curvature R7 of the object side surface of the fourth lens and a radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.7 < (R7+R8) / CT6 < 2.5.

[0016] According to an embodiment of the present application, an effective focal length f of the fisheye imaging lens and an effective focal length f4 of the fourth lens satisfy: 0.5 < f / f4 < 0.7.

[0017] The present application also provides a fisheye imaging lens, which comprises, in order along the optical axis from the object side to the image side: a first lens having negative refractive power, whose image side surface is concave; a second lens having refractive power; a third lens having positive refractive power, whose object side surface is convex; a stop; a fourth lens having positive refractive power; a fifth lens having refractive power; a sixth lens having positive refractive power;

[0018] Wherein, a refractive index N1 of the first lens, a refractive index N2 of the second lens, a refractive index N3 of the third lens, a refractive index N4 of the fourth lens, and a refractive index N5 of the fifth lens satisfy: 1.5 < (N1+N3+N5) / (N2+N4) < 2.0.

[0019] According to an embodiment of the present application, a distance SD of the stop to the image side surface of the sixth lens on the optical axis and a distance TD of the object side surface of the first lens to the image side surface of the sixth lens on the optical axis satisfy: 0.2 < SD / TD < 0.4.

[0020] According to an embodiment of the present application, the effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens satisfy: 1.3 < f3 / f4 < 4.3.

[0021] According to an embodiment of the present application, the effective focal length f1 of the first lens and the effective focal length f6 of the sixth lens satisfy: -2.0 < f1 / f6 < -1.2.

[0022] According to an embodiment of the present application, the central thickness CT3 of the third lens on the optical axis, the central thickness CT6 of the sixth lens on the optical axis and the effective focal length f of the fisheye imaging lens satisfy: 0.7 < (CT3-CT6) / f < 2.

[0023] According to an embodiment of the present application, the central thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 0.3 < CT2 / ET2 < 0.5.

[0024] According to an embodiment of the present application, the distance TTL of the fisheye imaging lens from the object side surface of the first lens to the imaging surface on the optical axis, the central thickness CT3 of the third lens on the optical axis and the central thickness CT4 of the fourth lens on the optical axis satisfy: 2.8 < TTL / (CT3+CT4) < 3.8.

[0025] According to an embodiment of the present application, the air separation thickness T34 of the third lens and the fourth lens on the optical axis and the air separation thickness T12 of the first lens and the second lens on the optical axis satisfy: 0 < Sin(0.5 x Semi-FOV) x T34 / T12 <= 0.2.

[0026] According to an embodiment of the present application, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.7 < (R7+R8) / CT6 < 2.5.

[0027] According to an embodiment of the present application, the effective focal length f of the fisheye imaging lens and the effective focal length f4 of the fourth lens satisfy: 0.5 < f / f4 < 0.7.

[0028] The beneficial effects of the present application are:

[0029] The fisheye imaging lens provided in the application comprises multiple lenses, such as a first lens to a sixth lens. By controlling the ratio of focal length to field angle, a large angle resolution can be achieved, and a wider field angle can be achieved in the same focal length section. The design of optical power and shape is stable in structure, and the assembly structure is stable during installation, and the imaging quality is high. By controlling the ratio of refractive index between the lenses, the edge light is smoothly transitioned, and the performance of the edge field is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0031] Figure 1 The lens group structure schematic diagram of the fisheye imaging lens embodiment 1 of the application is shown in FIG. 1.

[0032] Figures 2a-2b The astigmatism curve and the distortion curve of the fisheye imaging lens embodiment 1 of the application are shown in FIG. 2 and FIG. 3 respectively.

[0033] Figure 3 The lens group structure schematic diagram of the fisheye imaging lens embodiment 2 of the application is shown in FIG. 4.

[0034] Figures 4a-4b The astigmatism curve and the distortion curve of the fisheye imaging lens embodiment 2 of the application are shown in FIG. 5 and FIG. 6 respectively.

[0035] Figure 5 The lens group structure schematic diagram of the fisheye imaging lens embodiment 3 of the application is shown in FIG. 7.

[0036] Figures 6a-6b The astigmatism curve and the distortion curve of the fisheye imaging lens embodiment 3 of the application are shown in FIG. 8 and FIG. 9 respectively.

[0037] Figure 7 The lens group structure schematic diagram of the fisheye imaging lens embodiment 4 of the application is shown in FIG. 10.

[0038] Figures 8a-8b The astigmatism curve and the distortion curve of the fisheye imaging lens embodiment 4 of the application are shown in FIG. 11 and FIG. 12 respectively.

[0039] Figure 9 The lens group structure schematic diagram of the fisheye imaging lens embodiment 5 of the application is shown in FIG. 13.

[0040] Figures 10a-10b The astigmatism curve and the distortion curve of the fisheye imaging lens embodiment 5 of the application are shown in FIG. 14 and FIG. 15 respectively.

[0041] Figure 11A schematic view of a lens set structure of the fisheye imaging lens embodiment 6 of the present application;

[0042] Figures 12a-12b Astigmatism curve and distortion curve of the fisheye imaging lens embodiment 6 of the present application, respectively;

[0043] Figure 13 A schematic view of a lens set structure of the fisheye imaging lens embodiment 7 of the present application;

[0044] Figures 14a-14b Astigmatism curve and distortion curve of the fisheye imaging lens embodiment 7 of the present application, respectively. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without any creative effort fall within the scope of protection of the present application.

[0046] It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, 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.

[0047] It should also be understood that the words "comprise", "comprising", "include", "including", "contain", "containing", and / or "have", when used in the present specification, indicate the presence of the stated features, elements and / or components but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of" appear after a list of enumerated features, the phrase is intended to be interpreted to mean that the list of enumerated features is to be read as "one or more of the enumerated features". Furthermore, when describing embodiments of the present application, the use of "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0048] 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 or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn strictly to scale.

[0049] In the description of the present application, 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 surface is called the image side surface of the lens.

[0050] 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 idealized or overly formal sense unless expressly so defined herein.

[0051] It should be noted that the embodiments and features in the embodiments in the present application can be combined with each other without conflict. The features, principles and other aspects of the present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0052] Exemplary embodiments

[0053] The fisheye imaging lens of the exemplary embodiments of the present application includes six lenses, which, in order from the object side to the image side along the optical axis, include: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, wherein each lens is independent of each other, and each lens has an air gap on the optical axis.

[0054] In the exemplary embodiments, the fisheye imaging lens includes: a first lens with negative optical power, the image side surface of which is concave; a second lens with optical power; a third lens with positive optical power, the object side surface of which is convex; a stop; a fourth lens with positive optical power; a fifth lens with optical power; and a sixth lens with positive optical power.

[0055] In the exemplary embodiments, the effective focal length f1 of the first lens and half of the maximum field angle of the fisheye imaging lens Semi-FOV satisfy: 0.9mm < f1 / TAN(Semi-FOV) < 1.6mm. By controlling the ratio of the focal length of the first lens of the fisheye imaging lens to the field angle, a large angular resolution can be achieved, and a wider field angle can be achieved in the same focal length range. The design of optical power and shape is stable in structure, and the assembly structure is stable during installation, and the imaging quality is high. More specifically, the effective focal length f1 of the first lens and half of the maximum field angle of the fisheye imaging lens Semi-FOV satisfy: 0.91mm < f1 / TAN(Semi-FOV) < 1.59mm.

[0056] In the present exemplary embodiment, the refractive index Nl of the first lens, the refractive index N2 of the second lens, the refractive index N3 of the third lens, the refractive index N4 of the fourth lens, and the refractive index N5 of the fifth lens satisfy: 1.5 < (Nl+N3+N5) / (N2+N4) < 2.0. By controlling the ratio of the refractive index between the respective lenses, the edge ray is smoothly transitioned, and the performance of the edge field of view is improved. More specifically, the refractive index Nl of the first lens, the refractive index N2 of the second lens, the refractive index N3 of the third lens, the refractive index N4 of the fourth lens, and the refractive index N5 of the fifth lens satisfy: 1.51 < (Nl+N3+N5) / (N2+N4) < 1.99.

[0057] In the present exemplary embodiment, the distance SD from the diaphragm to the image side surface of the sixth lens on the optical axis and the distance TD from the object side surface of the first lens to the image side surface of the sixth lens on the optical axis satisfy: 0.2 < SD / TD < 0.4. By controlling the ratio of SD to TD within this range, the lens is easily manufactured, and the overall performance is improved. More specifically, the distance SD from the diaphragm to the image side surface of the sixth lens on the optical axis and the distance TD from the object side surface of the first lens to the image side surface of the sixth lens on the optical axis satisfy: 0.21 < SD / TD < 0.39.

[0058] In the present exemplary embodiment, the effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens satisfy: 1.3 < f3 / f4 < 4.3. By controlling the ratio of f3 to f4 within this range, the deflection angle of the edge field of view at the third and fourth lenses can be controlled, and the sensitivity of the system can be effectively reduced. More specifically, the effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens satisfy: 1.31 < f3 / f4 < 4.29.

[0059] In the present exemplary embodiment, the effective focal length f1 of the first lens and the effective focal length f6 of the sixth lens satisfy: -2.0 < f1 / f6 < -1.2. By controlling the ratio of f1 to f6 within this range, the deflection angle of the edge field of view at the first and sixth lenses can be controlled, and the sensitivity of the system can be effectively reduced. More specifically, the effective focal length f1 of the first lens and the effective focal length f6 of the sixth lens satisfy: -1.99 < f1 / f6 < -1.19.

[0060] In the present exemplary embodiment, the center thickness CT3 of the third lens on the optical axis, the center thickness CT6 of the sixth lens on the optical axis, and the effective focal length f of the fisheye imaging lens satisfy: 0.7 < (CT3-CT6) / f < 2. By reasonably allocating the optical power and the medium thickness of the system, the system can have good imaging quality and reduce the process sensitivity, and the product yield is improved. More specifically, the center thickness CT3 of the third lens on the optical axis, the center thickness CT6 of the sixth lens on the optical axis, and the effective focal length f of the fisheye imaging lens satisfy: 0.71 < (CT3-CT6) / f < 1.99.

[0061] In the present exemplary embodiment, the center thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 0.3 < CT2 / ET2 < 0.5. By controlling the ratio of CT2 and ET2 within this range, the shape of the second lens is controlled, and the lens forming and assembling yield is improved. More specifically, the center thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 0.31 < CT2 / ET2 < 0.49.

[0062] In the present exemplary embodiment, the distance TTL from the object side of the first lens to the imaging surface on the optical axis of the fisheye imaging lens, the center thickness CT3 of the third lens on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis satisfy: 2.8 < TTL / (CT3+CT4) < 3.8. By restricting the center thickness of the third and fourth lenses within a reasonable range, the processing performance is ensured, and the thinness is also ensured. More specifically, the distance TTL from the object side of the first lens to the imaging surface on the optical axis of the fisheye imaging lens, the center thickness CT3 of the third lens on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis satisfy: 2.81 < TTL / (CT3+CT4) < 3.79.

[0063] In the present exemplary embodiment, the air gap thickness T34 of the third lens and the fourth lens on the optical axis and the air gap thickness T12 of the first lens and the second lens on the optical axis satisfy: 0 < Sin(0.5 x Semi-FOV) x T34 / T12 <= 0.2. By controlling the ratio between the air gap thickness of the third lens and the fourth lens on the optical axis and the air gap thickness of the first lens and the second lens on the optical axis, the overall layout of the system is balanced, the incident large-angle light is deflected, the incident angle of the light on the subsequent lens is reduced, and the overall structure is compact. More specifically, the air gap thickness T34 of the third lens and the fourth lens on the optical axis and the air gap thickness T12 of the first lens and the second lens on the optical axis satisfy: 0.01 < Sin(0.5 x Semi-FOV) x T34 / T12 <= 0.20.

[0064] In the present exemplary embodiment, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.7 < (R7+R8) / CT6 < 2.5. By controlling the ratio of the radius of curvature of the object side surface and the image side surface of the fourth lens to the thickness of the sixth lens, the incident angle of the chief ray of each field of view of the fisheye imaging lens on the image plane can be controlled relatively reasonably, satisfying the requirement of the incident angle of the chief ray of the optical system design. More specifically, the radius of curvature R7 of the object side surface of the fourth lens and the radius of curvature R8 of the image side surface of the fourth lens satisfy: 0.71 < (R7+R8) / CT6 < 2.49.

[0065] In the present exemplary embodiment, the effective focal length f of the fisheye imaging lens and the effective focal length f4 of the fourth lens satisfy: 0.5 < f / f4 < 0.7. By reasonably distributing the optical power of the system, the system can have good imaging quality and reduce process sensitivity, improving product yield. More specifically, the effective focal length f of the fisheye imaging lens and the effective focal length f4 of the fourth lens satisfy: 0.51 < f / f4 < 0.69.

[0066] In the present exemplary embodiment, the object side surface and the image side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces, and the surface type x of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0067]

[0068] wherein x is the sag of the aspherical surface at a position along the optical axis at a height h 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); k is the conic coefficient; and Ai is the correction coefficient of the i-th order of the aspherical surface.

[0069] In the present exemplary embodiment, the fisheye imaging lens described above can further include a diaphragm. The diaphragm can be disposed at a suitable position as needed, for example, the diaphragm can be disposed between the image side of the third lens and the object side of the fourth lens. Alternatively, the fisheye imaging lens described above can further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging plane.

[0070] The fisheye imaging lens according to the above-described embodiments of the present application can employ multiple lenses, for example, the above-described six lenses. By reasonably distributing the optical power, surface type, central thickness of each lens, and axial distance between lenses, etc., the fisheye imaging lens has a relatively large imaging image plane, can achieve a large angular resolution, and can achieve a wider field of view in the same focal length range.

[0071] In the exemplary embodiments, at least one of the mirror surfaces of the lenses is an aspheric mirror surface, i.e., at least one of the object side surface to the image side surface of the first lens to the sixth lens is an aspheric mirror surface. The aspheric lens is characterized in that the curvature continuously changes from the center of the lens to the periphery of the lens, unlike the spherical lens which has a constant curvature from the center of the lens to the periphery of the lens, the aspheric lens has a better curvature radius characteristic, and has the advantages of improving the distortion aberration and improving the astigmatism aberration. After the aspheric lens is used, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, at least one of the object side surface and the image side surface of each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens is an aspheric mirror surface. Optionally, the object side surface and the image side surface of each of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are aspheric mirror surfaces.

[0072] However, those skilled in the art should understand that the number of lenses constituting the fisheye imaging 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 six lenses are described in the embodiments, the fisheye imaging lens is not limited to including six lenses, and the fisheye imaging lens can also include other numbers of lenses if necessary.

[0073] The specific embodiments of the fisheye imaging lens suitable for the above-mentioned embodiments are further described below with reference to the accompanying drawings. Specific Embodiment 1

[0075] Figure 1 The lens group structure diagram of the fisheye imaging lens embodiment 1 of the present application is shown in FIG. 1. The fisheye imaging lens includes, in order along the optical axis from the object side to the image side, a first lens E1, a second lens E2, a third lens E3, a stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a filter E7 and an imaging surface S15.

[0076] The first lens E1 has a negative optical power, the object side surface S1 is a convex surface, and the image side surface S2 is a concave surface. The second lens E2 has a negative optical power, the object side surface S3 is a convex surface, and the image side surface S4 is a concave surface. The third lens E3 has a positive optical power, the object side surface S5 is a convex surface, and the image side surface S6 is a convex surface. The fourth lens E4 has a positive optical power, the object side surface S7 is a convex surface, and the image side surface S8 is a convex surface. The fifth lens E5 has a negative optical power, the object side surface S9 is a concave surface, and the image side surface S10 is a concave surface. The sixth lens E6 has a positive optical power, the object side surface S11 is a convex surface, and the image side surface S12 is a convex surface. The filter E7 has an object side surface S13 and an image side surface S14. The light from the object sequentially passes through each of the surfaces S1 to S14 and is finally imaged on the imaging surface S15.

[0077] As shown in Table 1, a basic parameter table of the fisheye imaging lens of Example 1 is shown, wherein the units of the radius of curvature, thickness, and focal length are millimeters (mm).

[0078]

[0079] Table 1

[0080] As shown in Table 2, in Example 1, the total effective focal length f of the fisheye imaging lens is 1.03 mm, the distance TTL on the optical axis from the object side S1 of the first lens E1 to the imaging surface S15 of the fisheye imaging lens is 10.50 mm, and the half of the maximum field angle Semi-FOV of the fisheye imaging lens is 105.0°.

[0081]

[0082]

[0083] Table 2

[0084] The fisheye imaging lens in Example 1 satisfies:

[0085] f1 / TAN(Semi-FOV) = 1.26, where f1 is the effective focal length of the first lens, and Semi-FOV is the half of the maximum field angle of the fisheye imaging lens.

[0086] (N1+N3+N5) / (N2+N4) = 1.69, where N1 is the refractive index of the first lens, N2 is the refractive index of the second lens N2, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, and N5 is the refractive index of the fifth lens.

[0087] SD / TD = 0.28, where SD is the distance on the optical axis from the stop to the image side of the sixth lens, and TD is the distance on the optical axis from the object side of the first lens to the image side of the sixth lens.

[0088] f3 / f4 = 1.75, where f4 is the effective focal length of the fourth lens, and f3 is the effective focal length of the third lens.

[0089] f1 / f6 = -1.87, where f1 is the effective focal length of the first lens, and f6 is the effective focal length of the sixth lens.

[0090] (CT3-CT6) / f = 0.93, where CT3 is the center thickness of the third lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, and f is the effective focal length of the fisheye imaging lens.

[0091] CT2 / ET2 = 0.40, where CT2 is the center thickness of the second lens on the optical axis, and ET2 is the edge thickness of the second lens.

[0092] TTL / (CT3+CT4)=3.70, where TTL is the distance from the object side surface of the first lens of the fisheye imaging lens to the imaging surface on the optical axis, CT3 is the center thickness of the third lens on the optical axis, and CT4 is the center thickness of the fourth lens on the optical axis.

[0093] Sin(0.5xSemi-FOV)xT34 / T12=0.09, where T34 is the air gap thickness of the third lens and the fourth lens on the optical axis, and T12 is the air gap thickness of the first lens and the second lens on the optical axis.

[0094] (R7+R8) / CT6=2.38, where R7 is the radius of curvature of the object side surface of the fourth lens, and R8 is the radius of curvature of the image side surface of the fourth lens.

[0095] f / f4=0.64, where f is the effective focal length of the fisheye imaging lens, and f4 is the effective focal length of the fourth lens.

[0096] In the embodiment 1, the object side surface and the image side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces, and Table 3 shows the high order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, and A26 of the aspherical surfaces S1-S12 which can be used in the embodiment 1. 10 12 14 16 18 20

[0097]

[0098]

[0099] Table 3

[0100] Figure 2a Figure 6 shows the astigmatism curve of the fisheye imaging lens of the embodiment 1, which represents the meridional image surface curvature and the sagittal image surface curvature. Figure 2b Figure 7 shows the distortion curve of the fisheye imaging lens of the embodiment 1, which represents the distortion size values corresponding to different image heights. As shown in Figure 7, the fisheye imaging lens given in the embodiment 1 can achieve good imaging quality. Figures 2a-2b Specific Embodiment 2

[0102] Figure 3 ​​​​​​​Fig. 2 shows a schematic view of a lens structure of the fisheye imaging lens according to Embodiment 2. The fisheye imaging lens includes, in order from the object side to the image side along the optical axis, a first lens E1, a second lens E2, a third lens E3, a stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a filter E7, and an imaging surface S15.

[0103] The first lens E1 has negative refractive power, the object side surface S1 is convex, and the image side surface S2 is concave. The second lens E2 has negative refractive power, the object side surface S3 is convex, and the image side surface S4 is concave. The third lens E3 has positive refractive power, the object side surface S5 is convex, and the image side surface S6 is convex. The fourth lens E4 has positive refractive power, the object side surface S7 is convex, and the image side surface S8 is convex. The fifth lens E5 has negative refractive power, the object side surface S9 is concave, and the image side surface S10 is concave. The sixth lens E6 has positive refractive power, the object side surface S11 is convex, and the image side surface S12 is convex. The filter E7 has an object side surface S13 and an image side surface S14. Light from an object sequentially passes through each of the surfaces S1 to S14 and is finally imaged on the imaging surface S15.

[0104] As shown in Table 4, the fisheye imaging lens according to Embodiment 2 has the following basic parameters, wherein the radius of curvature, the thickness, and the focal length are all in millimeters (mm).

[0105]

[0106]

[0107] Table 4

[0108] As shown in Table 5, in Embodiment 2, the total effective focal length of the fisheye imaging lens is f = 1.03 mm, the distance from the object side surface S1 of the first lens E1 to the imaging surface S15 of the fisheye imaging lens on the optical axis is TTL = 10.30 mm, and the half of the maximum field angle of the fisheye imaging lens is Semi-FOV = 105.0°.

[0109]

[0110] Table 5

[0111] The fisheye imaging lens according to Embodiment 2 satisfies:

[0112] f1 / TAN(Semi-FOV) = 1.27, wherein f1 is the effective focal length of the first lens, and Semi-FOV is the half of the maximum field angle of the fisheye imaging lens.

[0113] (N1+N3+N5) / (N2+N4)=1.70, where N1 is the refractive index of the first lens, N2 is the refractive index of the second lens, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, and N5 is the refractive index of the fifth lens.

[0114] SD / TD = 0.30, where SD is the distance on the optical axis from the aperture stop to the image side of the sixth lens, and TD is the distance on the optical axis from the object side of the first lens to the image side of the sixth lens.

[0115] f3 / f4 = 1.95, where f4 is the effective focal length of the fourth lens and f3 is the effective focal length of the third lens.

[0116] f1 / f6 = -1.50, where f1 is the effective focal length of the first lens and f6 is the effective focal length of the sixth lens.

[0117] (CT3-CT6) / f=1.22, where CT3 is the center thickness of the third lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, and f is the effective focal length of the fisheye lens.

[0118] CT2 / ET2 = 0.41, where CT2 is the center thickness of the second lens on the optical axis and ET2 is the edge thickness of the second lens.

[0119] TTL / (CT3+CT4)=3.12, where TTL is the distance on the optical axis from the object side of the first lens of the fisheye lens to the imaging plane, CT3 is the center thickness of the third lens on the optical axis, and CT4 is the center thickness of the fourth lens on the optical axis.

[0120] Sin(0.5×Semi-FOV)×T34 / T12=0.04, where T34 is the air gap thickness between the third and fourth lenses on the optical axis, and T12 is the air gap thickness between the first and second lenses on the optical axis.

[0121] (R7+R8) / CT6=1.69, where R7 is the radius of curvature of the object side of the fourth lens and R8 is the radius of curvature of the image side of the fourth lens.

[0122] f / f4 = 0.62, where f is the effective focal length of the fisheye lens and f4 is the effective focal length of the fourth lens.

[0123] In Example 2, the object-side surface and image-side surface of any one of the lenses, from the first lens E1 to the sixth lens E6, are aspherical. Table 6 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S12 in Example 2. 10 A 12 A 14 A16 A 18 and A 20 .

[0124] Face number A4 A6 A8 A10 A12 A14 A16 S3 -1.3571E-02 -1.1682E-02 3.8399E-03 5.0451E-03 -4.7709E-03 1.8430E-03 -3.8034E-04 S4 -2.5184E-02 3.1088E-01 -1.5661E+00 3.6868E+00 -5.0406E+00 4.2237E+00 -2.1503E+00 S7 -2.9160E-02 1.5403E-01 -1.7637E+00 9.7962E+00 -3.5455E+01 7.9751E+01 -1.0792E+02 S8 4.7147E-01 -3.4129E+00 1.1136E+01 -2.5005E+01 3.9035E+01 -4.1512E+01 2.8556E+01 S9 6.9595E-01 -4.4854E+00 1.5115E+01 -3.8036E+01 6.8027E+01 -8.2240E+01 6.3226E+01 S10 1.8858E-01 -9.2554E-01 2.3032E+00 -3.5103E+00 2.8566E+00 -4.4586E-01 -1.2092E+00 S11 -2.0527E-01 5.2345E-01 -1.1988E+00 2.8957E+00 -5.0157E+00 5.4261E+00 -3.4983E+00 S12 -1.0258E-01 -1.9207E-02 2.2465E-01 -2.7963E-01 7.6829E-02 2.1281E-01 -2.4934E-01 Face number A18 A20 S3 4.1239E-05 -1.8524E-06 S4 6.1225E-01 -7.4942E-02 S7 7.8594E+01 -2.3041E+01 S8 -1.1436E+01 2.0245E+00 S9 -2.7566E+01 5.1425E+00 S10 9.5495E-01 -2.2438E-01 S11 1.2262E+00 -1.7899E-01 S12 1.0445E-01 -1.5548E-02

[0125] Table 6

[0126] Figure 4a The astigmatism curve of the fisheye lens of Embodiment 2 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 4b The distortion curve of the fisheye lens in Example 2 is shown, representing the distortion magnitude corresponding to different image heights. According to... Figures 4a-4b As shown, the fisheye lens given in Example 2 can achieve good imaging quality. Specific Implementation Example 3

[0128] Figure 5 This is a schematic diagram of the lens group structure of embodiment 3 of the fisheye imaging lens of this application. The fisheye imaging lens includes, in sequence from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, an aperture stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a filter E7, and an imaging surface S15.

[0129] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being concave and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0130] Table 7 shows the basic parameters of the fisheye lens in Example 3, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0131]

[0132] Table 7

[0133] As shown in Table 8, in Example 3, the total effective focal length f of the fisheye lens is 1.03 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S15 of the fisheye lens on the optical axis is 10.50 mm, and half of the maximum field of view of the fisheye lens, Semi-FOV, is 105.0°.

[0134]

[0135] Table 8

[0136] The fisheye imaging lens in Example 3 satisfies:

[0137] f1 / TAN(Semi-FOV) = 1.30, where f1 is the effective focal length of the first lens, and Semi-FOV is half of the maximum field angle of the fisheye imaging lens.

[0138] (N1+N3+N5) / (N2+N4) = 1.77, where N1 is the refractive index of the first lens, N2 is the refractive index of the second lens N2, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, and N5 is the refractive index of the fifth lens.

[0139] SD / TD = 0.29, where SD is the distance on the optical axis from the stop to the image side surface of the sixth lens, and TD is the distance on the optical axis from the object side surface of the first lens to the image side surface of the sixth lens.

[0140] f3 / f4 = 4.19, where f4 is the effective focal length of the fourth lens, and f3 is the effective focal length of the third lens.

[0141] f1 / f6 = -1.32, where f1 is the effective focal length of the first lens, and f6 is the effective focal length of the sixth lens.

[0142] (CT3-CT6) / f = 1.46, where CT3 is the center thickness on the optical axis of the third lens, CT6 is the center thickness on the optical axis of the sixth lens, and f is the effective focal length of the fisheye imaging lens.

[0143] CT2 / ET2 = 0.45, where CT2 is the center thickness on the optical axis of the second lens, and ET2 is the edge thickness of the second lens.

[0144] TTL / (CT3+CT4) = 3.12, where TTL is the distance on the optical axis from the object side surface of the fisheye imaging lens first lens to the imaging surface, CT3 is the center thickness on the optical axis of the third lens, and CT4 is the center thickness on the optical axis of the fourth lens.

[0145] Sin(0.5 x Semi-FOV) x T34 / T12 = 0.04, where T34 is the air separation thickness on the optical axis of the third lens and the fourth lens, and T12 is the air separation thickness on the optical axis of the first lens and the second lens.

[0146] (R7+R8) / CT6=1.47, where R7 is the radius of curvature of the object side of the fourth lens and R8 is the radius of curvature of the image side of the fourth lens.

[0147] f / f4 = 0.67, where f is the effective focal length of the fisheye lens and f4 is the effective focal length of the fourth lens.

[0148] In Example 3, the object-side surface and image-side surface of any one of the lenses, from the first lens E1 to the sixth lens E6, are aspherical. Table 9 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S12 in Example 3. 10 A 12 A 14 A 16 A 18 and A 20 .

[0149] Face number A4 A6 A8 A10 A12 A14 A16 S3 4.4421E-02 -1.8292E-02 -2.3757E-03 6.5032E-03 -3.5202E-03 1.0298E-03 -1.7667E-04 S4 2.2671E-01 -1.8920E-01 4.4606E-01 -9.3797E-01 1.2268E+00 -9.2063E-01 3.6866E-01 S7 -9.1925E-03 -6.9013E-02 1.7415E-01 -6.8593E-01 1.4723E+00 -2.8068E+00 4.1705E+00 S8 2.0118E-01 -2.0681E+00 7.2266E+00 -1.6819E+01 2.6017E+01 -2.6467E+01 1.6987E+01 S9 7.4481E-01 -4.1584E+00 1.4433E+01 -3.7390E+01 6.7059E+01 -8.0493E+01 6.1142E+01 S10 1.0978E-01 -4.9726E-01 1.5865E+00 -3.7100E+00 5.4990E+00 -5.0813E+00 2.8510E+00 S11 -1.1148E-01 8.7732E-02 2.3178E-02 3.2805E-01 -1.1793E+00 1.7314E+00 -1.3876E+00 S12 -5.5486E-02 6.8664E-02 -2.5162E-01 5.8080E-01 -7.0422E-01 4.7604E-01 -1.4779E-01 Face number A18 A20 S3 1.6748E-05 -6.7973E-07 S4 -6.2955E-02 9.1772E-04 S7 -3.8736E+00 1.5416E+00 S8 -6.2347E+00 9.9653E-01 S9 -2.6251E+01 4.8157E+00 S10 -8.8837E-01 1.1833E-01 S11 5.9873E-01 -1.0982E-01 S12 2.1008E-03 5.9031E-03

[0150] Table 9

[0151] Figure 6a The astigmatism curve of the fisheye lens of Embodiment 3 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 6b The distortion curve of the fisheye lens in Example 3 is shown, representing the distortion magnitude corresponding to different image heights. According to... Figures 6a-6b As shown, the fisheye lens given in Example 3 can achieve good imaging quality. Specific Implementation Example 4

[0153] Figure 7 This is a schematic diagram of the lens group structure of embodiment 4 of the fisheye imaging lens of this application. The fisheye imaging lens includes, in sequence from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, an aperture stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a filter E7, and an imaging surface S15.

[0154] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being concave and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0155] As shown in Table 10, a basic parameter table of the fisheye imaging lens of Example 4 is shown, wherein the units of the radius of curvature, the thickness, and the focal length are all millimeters (mm).

[0156]

[0157] Table 10

[0158] As shown in Table 11, in Example 4, the total effective focal length of the fisheye imaging lens f = 1.03 mm, the distance on the optical axis from the object side S1 of the first lens E1 to the imaging surface S15 of the fisheye imaging lens TTL = 10.30 mm, and the half of the maximum field angle of the fisheye imaging lens Semi-FOV = 105.0°.

[0159]

[0160] Table 11

[0161] The fisheye imaging lens in Example 4 satisfies:

[0162] f1 / TAN(Semi-FOV) = 1.30, wherein f1 is the effective focal length of the first lens, and Semi-FOV is the half of the maximum field angle of the fisheye imaging lens.

[0163] (N1+N3+N5) / (N2+N4) = 1.77, wherein N1 is the refractive index of the first lens, N2 is the refractive index of the second lens N2, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, and N5 is the refractive index of the fifth lens.

[0164] SD / TD = 0.32, wherein SD is the distance on the optical axis from the stop to the image side of the sixth lens, and TD is the distance on the optical axis from the object side of the first lens to the image side of the sixth lens.

[0165] f3 / f4 = 3.06, wherein f4 is the effective focal length of the fourth lens, and f3 is the effective focal length of the third lens.

[0166] f1 / f6 = -1.74, wherein f1 is the effective focal length of the first lens, and f6 is the effective focal length of the sixth lens.

[0167] (CT3-CT6) / f = 0.80, wherein CT3 is the center thickness of the third lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, and f is the effective focal length of the fisheye imaging lens.

[0168] CT2 / ET2 = 0.46, wherein CT2 is the center thickness of the second lens on the optical axis, and ET2 is the edge thickness of the second lens.

[0169] TTL / (CT3+CT4)=3.42, where TTL is the distance from the object side surface of the first lens of the fisheye imaging lens to the imaging surface on the optical axis, CT3 is the center thickness of the third lens on the optical axis, and CT4 is the center thickness of the fourth lens on the optical axis.

[0170] Sin(0.5xSemi-FOV)xT34 / T12=0.04, where T34 is the air gap thickness of the third lens and the fourth lens on the optical axis, and T12 is the air gap thickness of the first lens and the second lens on the optical axis.

[0171] (R7+R8) / CT6=0.79, where R7 is the radius of curvature of the object side surface of the fourth lens, and R8 is the radius of curvature of the image side surface of the fourth lens.

[0172] f / f4=0.66, where f is the effective focal length of the fisheye imaging lens, and f4 is the effective focal length of the fourth lens.

[0173] In Embodiment 4, the object side surface and the image side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces, and Table 12 shows the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, and A26 of the aspherical surfaces S1-S12 that can be used in Embodiment 4. 10 12 14 16 18 20

[0174]

[0175]

[0176] Table 12

[0177] Figure 8a Figure 8 shows the astigmatism curve of the fisheye imaging lens of Embodiment 4, which represents the meridional image surface curvature and the sagittal image surface curvature. Figure 8b Figure 9 shows the distortion curve of the fisheye imaging lens of Embodiment 4, which represents the distortion size values corresponding to different image heights. As shown in Figure 9, the fisheye imaging lens given in Embodiment 4 can achieve good imaging quality. Figures 8a-8b Specific Embodiment 5

[0179] Figure 9 Figure 10 is a schematic diagram of the lens group structure of Embodiment 5 of the fisheye imaging lens of the present application, which includes, in order from the object side to the image side along the optical axis, the first lens E1, the second lens E2, the third lens E3, the stop STO, the fourth lens E4, the fifth lens E5, the sixth lens E6, the filter E7, and the imaging surface S15.​​​​​​​

[0180] The first lens E1 has negative focal power, the object side surface S1 is convex, and the image side surface S2 is concave. The second lens E2 has negative focal power, the object side surface S3 is convex, and the image side surface S4 is concave. The third lens E3 has positive focal power, the object side surface S5 is convex, and the image side surface S6 is convex. The fourth lens E4 has positive focal power, the object side surface S7 is convex, and the image side surface S8 is convex. The fifth lens E5 has negative focal power, the object side surface S9 is concave, and the image side surface S10 is concave. The sixth lens E6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex. The filter E7 has an object side surface S13 and an image side surface S14. Light from an object sequentially passes through each of the surfaces S1 to S14 and is finally imaged on the imaging surface S15.

[0181] As shown in Table 13, a basic parameter table of the fisheye imaging lens of Example 5 is shown, wherein the units of the radius of curvature, the thickness, and the focal length are all millimeters (mm).

[0182]

[0183]

[0184] Table 13

[0185] As shown in Table 14, in Example 5, the total effective focal length of the fisheye imaging lens f = 1.03 mm, the distance on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S15 of the fisheye imaging lens TTL = 10.44 mm, and the half of the maximum field angle of the fisheye imaging lens Semi-FOV = 106.0°.

[0186]

[0187] Table 14

[0188] The fisheye imaging lens in Example 5 satisfies:

[0189] f1 / TAN(Semi-FOV) = 1.37, where f1 is the effective focal length of the first lens, and Semi-FOV is the half of the maximum field angle of the fisheye imaging lens.

[0190] (N1+N3+N5) / (N2+N4) = 1.71, where N1 is the refractive index of the first lens, N2 is the refractive index of the second lens N2, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, and N5 is the refractive index of the fifth lens.

[0191] SD / TD = 0.26, where SD is the distance on the optical axis from the stop to the image side surface of the sixth lens, and TD is the distance on the optical axis from the object side surface of the first lens to the image side surface of the sixth lens.

[0192] f3 / f4 = 1.56, where f4 is the effective focal length of the fourth lens and f3 is the effective focal length of the third lens.

[0193] f1 / f6 = -1.62, where f1 is the effective focal length of the first lens and f6 is the effective focal length of the sixth lens.

[0194] (CT3-CT6) / f=1.83, where CT3 is the center thickness of the third lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, and f is the effective focal length of the fisheye lens.

[0195] CT2 / ET2 = 0.42, where CT2 is the center thickness of the second lens on the optical axis and ET2 is the edge thickness of the second lens.

[0196] TTL / (CT3+CT4)=2.95, where TTL is the distance on the optical axis from the object side of the first lens of the fisheye lens to the imaging plane, CT3 is the center thickness of the third lens on the optical axis, and CT4 is the center thickness of the fourth lens on the optical axis.

[0197] Sin(0.5×Semi-FOV)×T34 / T12=0.10, where T34 is the air gap thickness between the third and fourth lenses on the optical axis, and T12 is the air gap thickness between the first and second lenses on the optical axis.

[0198] (R7+R8) / CT6=1.51, where R7 is the radius of curvature of the object side of the fourth lens and R8 is the radius of curvature of the image side of the fourth lens.

[0199] f / f4 = 0.56, where f is the effective focal length of the fisheye lens and f4 is the effective focal length of the fourth lens.

[0200] In Example 5, the object-side surface and image-side surface of any one of the lenses, from the first lens E1 to the sixth lens E6, are aspherical. Table 15 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S12 in Example 5. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0201] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.1918E-01 -2.0632E-01 3.9832E-01 -8.1452E-01 1.2887E+00 -1.4487E+00 1.1559E+00 S4 2.6871E-01 -1.5011E+00 1.4033E+01 -9.1654E+01 3.9992E+02 -1.2121E+03 2.6232E+03 S7 1.5907E-02 -3.3239E-02 8.6930E-02 -2.6725E-01 2.5706E-01 -1.1894E-01 0.0000E+00 S8 1.0640E-01 -3.2322E-01 -4.0013E-01 1.5990E+01 -1.0879E+02 4.2276E+02 -1.1025E+03 S9 -7.0150E-02 -2.8464E+00 2.3343E+01 -1.0076E+02 2.2959E+02 -3.5287E+01 -1.5962E+03 S10 4.3313E-01 -4.7545E+00 3.1534E+01 -1.6259E+02 6.6417E+02 -2.0898E+03 4.9459E+03 S11 3.5429E-01 -1.1798E+00 -1.8639E+00 3.4418E+01 -1.6544E+02 4.7469E+02 -9.1195E+02 S12 1.4132E-01 -2.6859E-01 3.6780E+00 -3.3280E+01 1.6802E+02 -5.3928E+02 1.1787E+03 Face number A18 A20 A22 A24 A26 A28 A30 S3 -6.6069E-01 2.7135E-01 -7.9410E-02 1.6157E-02 -2.1719E-03 1.7338E-04 -6.2243E-06 S4 -4.1070E+03 4.6577E+03 -3.7842E+03 2.1445E+03 -8.0412E+02 1.7915E+02 -1.7944E+01 S7 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S8 2.0306E+03 -2.6781E+03 2.5134E+03 -1.6373E+03 7.0286E+02 -1.7862E+02 2.0335E+01 S9 5.7598E+03 -1.1254E+04 1.4088E+04 -1.1605E+04 6.1077E+03 -1.8660E+03 2.5213E+02 S10 -8.6824E+03 1.1175E+04 -1.0370E+04 6.7368E+03 -2.9030E+03 7.4467E+02 -8.6006E+01 S11 1.2034E+03 -1.0766E+03 6.1697E+02 -1.9051E+02 6.8810E+00 1.3913E+01 -3.0392E+00 S12 -1.8140E+03 1.9897E+03 -1.5486E+03 8.3590E+02 -2.9752E+02 6.2784E+01 -5.9474E+00

[0202] Table 15

[0203] Figure 10a The astigmatism curve of the fisheye lens of Embodiment 5 is shown, which represents the meridional image plane curvature and the sagittal image plane curvature. Figure 10b The distortion curve of the fisheye lens in Example 5 is shown, representing the distortion magnitude corresponding to different image heights. According to... Figures 10a-10b As shown, the fisheye lens given in Example 5 can achieve good imaging quality. Specific Implementation Example 6

[0205] Figure 11 This is a schematic diagram of the lens group structure of Embodiment 6 of the fisheye imaging lens of this application. The fisheye imaging lens includes, in sequence from the object side to the image side along the optical axis: a first lens E1, a second lens E2, a third lens E3, an aperture stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a filter E7, and an imaging surface S15.

[0206] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has negative optical power, with its object-side surface S3 being concave and its image-side surface S4 being concave. The third lens E3 has positive optical power, with its object-side surface S5 being convex and its image-side surface S6 being convex. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has negative optical power, with its object-side surface S9 being concave and its image-side surface S10 being concave. The sixth lens E6 has positive optical power, with its object-side surface S11 being convex and its image-side surface S12 being convex. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0207] Table 16 shows the basic parameters of the fisheye lens in Example 6, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0208]

[0209] Table 16

[0210] As shown in Table 17, in Example 6, the total effective focal length f of the fisheye lens is 1.03 mm, the distance TTL from the object side surface S1 of the first lens E1 to the imaging surface S15 of the fisheye lens on the optical axis is 10.49 mm, and half of the maximum field of view of the fisheye lens, Semi-FOV, is 105.0°.

[0211]

[0212]

[0213] Table 17

[0214] The fisheye imaging lens in Example 6 satisfies:

[0215] f1 / TAN(Semi-FOV) = 1.20, where f1 is the effective focal length of the first lens, and Semi-FOV is half of the maximum field angle of the fisheye imaging lens.

[0216] (N1+N3+N5) / (N2+N4) = 1.71, where N1 is the refractive index of the first lens, N2 is the refractive index of the second lens N2, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, and N5 is the refractive index of the fifth lens.

[0217] SD / TD = 0.25, where SD is the distance on the optical axis from the stop to the image side surface of the sixth lens, and TD is the distance on the optical axis from the object side surface of the first lens to the image side surface of the sixth lens.

[0218] f3 / f4 = 1.41, where f4 is the effective focal length of the fourth lens, and f3 is the effective focal length of the third lens.

[0219] f1 / f6 = -1.43, where f1 is the effective focal length of the first lens, and f6 is the effective focal length of the sixth lens.

[0220] (CT3-CT6) / f = 1.29, where CT3 is the center thickness on the optical axis of the third lens, CT6 is the center thickness on the optical axis of the sixth lens, and f is the effective focal length of the fisheye imaging lens.

[0221] CT2 / ET2 = 0.40, where CT2 is the center thickness on the optical axis of the second lens, and ET2 is the edge thickness of the second lens.

[0222] TTL / (CT3+CT4) = 3.48, where TTL is the distance on the optical axis from the object side surface of the first lens of the fisheye imaging lens to the imaging surface, CT3 is the center thickness on the optical axis of the third lens, and CT4 is the center thickness on the optical axis of the fourth lens.

[0223] Sin(0.5 x Semi-FOV) x T34 / T12 = 0.18, where T34 is the air separation thickness on the optical axis of the third lens and the fourth lens, and T12 is the air separation thickness on the optical axis of the first lens and the second lens.

[0224] (R7+R8) / CT6 = 1.57, where R7 is the radius of curvature of the object side surface of the fourth lens, and R8 is the radius of curvature of the image side surface of the fourth lens.

[0225] f / f4=0.55, where f is the effective focal length of the fisheye imaging lens, and f4 is the effective focal length of the fourth lens.

[0226] In Embodiment 6, the object side surface and the image side surface of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces, and Table 18 shows the high-order term 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 S1-S12 that can be used in Embodiment 6. 10 12 14 16 18 20 22 24 26 28 30 .

[0227]

[0228]

[0229] Table 18

[0230] Figure 12a Figure 19 shows the astigmatism curve of the fisheye imaging lens of Embodiment 6, which represents the meridional image curvature and the sagittal image curvature. Figure 12b Figure 20 shows the distortion curve of the fisheye imaging lens of Embodiment 6, which represents the distortion size values corresponding to different image heights. As shown in Figure 20, the fisheye imaging lens given in Embodiment 6 can achieve good imaging quality. Figures 12a-12b Specific Embodiment 7

[0232] Figure 13 Figure 21 is a schematic diagram of the lens group structure of Embodiment 7 of the fisheye imaging lens of the present application. The fisheye imaging lens includes, in order from the object side to the image side along the optical axis, a first lens E1, a second lens E2, a third lens E3, a stop STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a filter E7, and an imaging surface S15.

[0233] ​​​​​​​​​​​The first lens E1 has negative focal power, the object side surface S1 is convex, and the image side surface S2 is concave. The second lens E2 has negative focal power, the object side surface S3 is concave, and the image side surface S4 is concave. The third lens E3 has positive focal power, the object side surface S5 is convex, and the image side surface S6 is convex. The fourth lens E4 has positive focal power, the object side surface S7 is convex, and the image side surface S8 is convex. The fifth lens E5 has negative focal power, the object side surface S9 is convex, and the image side surface S10 is concave. The sixth lens E6 has positive focal power, the object side surface S11 is convex, and the image side surface S12 is convex. The filter E7 has an object side surface S13 and an image side surface S14. Light from an object sequentially passes through each of the surfaces S1 to S14 and is finally imaged on the imaging surface S15.

[0234] As shown in Table 19, a basic parameter table of the fisheye imaging lens of Example 7 is shown, wherein the units of the radius of curvature, the thickness, and the focal length are all millimeters (mm).

[0235]

[0236]

[0237] Table 19

[0238] As shown in Table 20, in the example, the total effective focal length of the fisheye imaging lens f = 1.09 mm, the distance on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S15 of the fisheye imaging lens TTL = 11.11 mm, and the half of the maximum field angle of the fisheye imaging lens Semi-FOV = 105.0°.

[0239]

[0240] Table 20

[0241] The fisheye imaging lens in Example 7 satisfies:

[0242] f1 / TAN(Semi-FOV) = 1.38, where f1 is the effective focal length of the first lens, and Semi-FOV is the half of the maximum field angle of the fisheye imaging lens.

[0243] (N1+N3+N5) / (N2+N4) = 1.77, where N1 is the refractive index of the first lens, N2 is the refractive index of the second lens N2, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, and N5 is the refractive index of the fifth lens.

[0244] SD / TD = 0.29, where SD is the distance on the optical axis from the stop to the image side surface of the sixth lens, and TD is the distance on the optical axis from the object side surface of the first lens to the image side surface of the sixth lens.

[0245] f3 / f4 = 4.19, where f4 is the effective focal length of the fourth lens and f3 is the effective focal length of the third lens.

[0246] f1 / f6 = -1.32, where f1 is the effective focal length of the first lens and f6 is the effective focal length of the sixth lens.

[0247] (CT3-CT6) / f = 1.46, where CT3 is the center thickness of the third lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, and f is the effective focal length of the fisheye imaging lens.

[0248] CT2 / ET2 = 0.45, where CT2 is the center thickness of the second lens on the optical axis and ET2 is the edge thickness of the second lens.

[0249] TTL / (CT3+CT4) = 3.12, where TTL is the distance from the fisheye imaging lens first lens object side to the imaging surface on the optical axis, CT3 is the center thickness of the third lens on the optical axis, and CT4 is the center thickness of the fourth lens on the optical axis.

[0250] Sin(0.5xSemi-FOV)xT34 / T12 = 0.04, where T34 is the air separation thickness of the third lens and the fourth lens on the optical axis, and T12 is the air separation thickness of the first lens and the second lens on the optical axis.

[0251] (R7+R8) / CT6 = 1.47, where R7 is the radius of curvature of the fourth lens object side, and R8 is the radius of curvature of the fourth lens image side.

[0252] f / f4 = 0.67, where f is the effective focal length of the fisheye imaging lens and f4 is the effective focal length of the fourth lens.

[0253] In embodiment 7, the object side and the image side of any one of the first lens E1 to the sixth lens E6 are aspherical surfaces, and Table 21 shows the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, and A26 that can be used for each aspherical surface S1-S12 in embodiment 7. 10 12 14 16 18 20

[0254] Face number A4 A6 A8 A10 A12 A14 A16 S3 -6.5616E-02 1.2906E-02 9.9013E-03 -9.2235E-03 3.7118E-03 -8.7832E-04 1.2623E-04 S4 -1.4163E-01 -2.0038E-02 9.7444E-02 -1.5775E-01 2.4436E-01 -3.1342E-01 2.3349E-01 S7 -4.2353E-02 3.7636E-01 -6.4101E+00 5.0613E+01 -2.4161E+02 6.9786E+02 -1.1946E+03 S8 3.8881E-01 -3.0838E+00 1.1064E+01 -2.8573E+01 5.1488E+01 -6.3008E+01 4.9887E+01 S9 5.1280E-01 -4.1486E+00 1.6203E+01 -4.6263E+01 9.1301E+01 -1.1885E+02 9.6684E+01 S10 1.6107E-01 -9.9829E-01 3.1425E+00 -6.1894E+00 7.5828E+00 -5.5051E+00 2.0324E+00 S11 -1.0619E-01 1.4075E-01 -2.9022E-01 1.3932E+00 -3.3735E+00 4.3660E+00 -3.1915E+00 S12 -1.1093E-01 2.0187E-01 -7.3902E-01 1.9877E+00 -3.2084E+00 3.2029E+00 -1.8993E+00 Face number A18 A20 S3 -1.0254E-05 3.6208E-07 S4 -8.8402E-02 1.3193E-02 S7 1.1062E+03 -4.2373E+02 S8 -2.3266E+01 4.9184E+00 S9 -4.4114E+01 8.5568E+00 S10 -1.8146E-01 -5.8630E-02 S11 1.2457E+00 -2.0178E-01 S12 6.0823E-01 -8.0887E-02

[0255] Table 21

[0256] Figure 14a The astigmatic curve of the fisheye imaging lens of embodiment 7 is shown, which represents the meridional image surface curvature and the sagittal image surface curvature. Figure 14b ​​​​​​The distortion curve of the fisheye imaging lens of embodiment 7 is shown, which represents the distortion size values corresponding to different image heights. According to Figures 14a-14b It can be seen from the figure that the fisheye imaging lens of embodiment 7 can achieve good imaging quality.

[0257] The above merely provides the preferred embodiments of the present application, but not for limiting the present application. Any modification, improvement, equivalent replacement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fisheye image capturing lens, characterized by, The fish-eye imaging lens has six pieces of lenses with optical power, and sequentially comprises, from the object side to the image side along the optical axis: a first lens with negative optical power, whose object side surface is convex and whose image side surface is concave; a second lens with negative optical power, whose image side surface is concave; a third lens with positive optical power, whose object side surface is convex and whose image side surface is convex; a stop; a fourth lens with positive optical power, whose object side surface is convex and whose image side surface is convex; a fifth lens with negative optical power, whose image side surface is concave; a sixth lens with positive optical power, whose object side surface is convex and whose image side surface is convex. Wherein, the refractive index N1 of the first lens, the refractive index N2 of the second lens, the refractive index N3 of the third lens, the refractive index N4 of the fourth lens and the refractive index N5 of the fifth lens satisfy: 1.69≤(N1+N3+N5) / (N2+N4)≤1.77; The central thickness CT3 of the third lens on the optical axis, the central thickness CT6 of the sixth lens on the optical axis and the effective focal length f of the fish-eye imaging lens satisfy: 0.8≤(CT3-CT6) / f≤1.83; The air separation thickness T34 of the third lens and the fourth lens on the optical axis and the air separation thickness T12 of the first lens and the second lens on the optical axis satisfy: 0.04≤Sin(0.5×Semi-FOV)×T34 / T12≤0.2; The effective focal length f1 of the first lens and the effective focal length f6 of the sixth lens satisfy: -1.87≤f1 / f6≤-1.32; The effective focal length f of the fish-eye imaging lens and the effective focal length f4 of the fourth lens satisfy: 0.55≤f / f4≤0.

67.

2. The fisheye image-taking lens according to claim 1, wherein: The distance SD of the stop to the image side surface of the sixth lens on the optical axis and the distance TD of the object side surface of the first lens to the image side surface of the sixth lens on the optical axis satisfy: 0.25≤SD / TD≤0.

32.

3. The fisheye image-taking lens according to claim 1, wherein: The effective focal length f4 of the fourth lens and the effective focal length f3 of the third lens satisfy: 1.41≤f3 / f4≤4.

19.

4. The fisheye image-taking lens according to claim 1, wherein: The central thickness CT2 of the second lens on the optical axis and the edge thickness ET2 of the second lens satisfy: 0.4≤CT2 / ET2<0.

5.

5. The fisheye image-taking lens according to claim 1, wherein: The distance TTL of the object side surface of the first lens of the fish-eye imaging lens to the imaging surface on the optical axis, the central thickness CT3 of the third lens on the optical axis and the central thickness CT4 of the fourth lens on the optical axis satisfy: 2.95≤TTL / (CT3+CT4)≤3.

7.

6. The fisheye image-taking lens according to claim 1, wherein: The curvature radius R7 of the object side surface of the fourth lens and the curvature radius R8 of the image side surface of the fourth lens satisfy: 0.79≤(R7+R8) / CT6≤2.38.

Images