Optical lens

Abstract

The invention discloses an optical lens which is sequentially arranged from an object side to an image side along an optical axis of the lens: a first lens which is a glass lens with negative focal power; the second lens has negative focal power; the third lens is provided with positive focal power; a fourth lens, wherein the fourth lens has positive focal power or negative focal power; an aperture stop; a fifth lens, wherein the fifth lens has a positive focal power or a negative focal power; a sixth lens having a positive focal power or a negative focal power; a seventh lens having a positive focal power or a negative focal power; and the eighth lens is a plastic lens with positive focal power or negative focal power. The lens is formed by mixing glass and plastic, the field angle is larger than or equal to 200 degrees, the aperture is larger than or equal to 1.9, and the lens has the advantages of being large in field of view, large in aperture, high in imaging quality and high in brightness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical lens, in particular to an optical lens for smart home. BACKGROUND

[0002] With the popularity of smart home, more and more optical lenses are used in the field of smart home, so that the position of optical lens in the field of smart home is continuously improved. At the same time, as people's experience requirements for smart home are continuously improved, the demand for optical lenses related to smart home is also increasing.

[0003] As for the optical lens for smart home, especially a large-angle fisheye lens, there are still many deficiencies, such as serious field distortion at the edge of the lens, serious squeezing of picture information, the need for software correction, large chromatic aberration of the lens, poor imaging quality at the edge area, easy to cause blue-purple edge, too large field angle of the lens, dispersed light quantity, and poor low-light effect, etc. SUMMARY

[0004] To solve the above technical problems, the present application provides an optical lens, which is composed of glass and plastic, and has the advantages of large field of view, large aperture, high imaging quality and high brightness.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] An optical lens, sequentially arranged from the object side to the image side along the optical axis of the lens, includes a first lens, a second lens, a third lens, a fourth lens, an aperture stop, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a filter and an image plane, the aperture stop is located between the fourth lens and the fifth lens, the filter is arranged on the image side of the eighth lens, and the imaging plane is arranged on the image side of the filter;

[0007] Wherein:

[0008] The first lens can have negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0009] The second lens can have negative focal power, the object side surface of which can be a convex surface or a concave surface, and the image side surface of which is a concave surface;

[0010] The third lens can have positive focal power, the object side surface of which is a convex surface, and the image side surface of which can be a concave surface or a convex surface;

[0011] The fourth lens can have positive focal power or negative focal power, the object side surface of which can be a convex surface or a concave surface, and the image side surface of which can be a concave surface or a convex surface;

[0012] The fifth lens can have positive focal power or negative focal power, the object side surface of which is a convex surface, and the image side surface of which can be a concave surface or a convex surface;

[0013] The sixth lens can have positive or negative focal power, and its object side surface can be convex or concave, and its image side surface can be concave or convex.

[0014] The seventh lens can have positive or negative focal power, and its object side surface can be convex or concave, and its image side surface can be concave or convex.

[0015] The eighth lens can have positive or negative focal power, and its object side surface can be convex or concave, and its image side surface can be concave or convex.

[0016] Further, in the present application, the first lens is a glass lens; the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are glass lenses or plastic lenses.

[0017] Further, in the present application, in view of the aberration of the optical system and the problem of different focusing distances, the focal length, the refractive index and the radius of curvature of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens respectively satisfy the following conditions:

[0018] f1 -9.11～-6.53 ND1 1.70～1.85 R11 +12.13～+13.21 R12 +3.75～+4.27 f2 -11.51～-6.98 ND2 1.52～1.56 R21 +1.50～+2.50 R22 +0.96～+1.45 f3 +5.22～+17.74 ND3 1.62～1.72 R31 +2.85～+6.54 R32 -10.99～+27.94 f4 -12.27～+16.47 ND4 1.52～1.79 R41 -5.70～-2.66 R42 -4.82～-3.06 f5 -25.49～+6.56 ND5 1.43～1.65 R51 +2.27～+2.99 R52 -130.95～+12.32 f6 -6.52～+3.24 ND6 1.43～1.90 R61 -27.48～+24.95 R62 -2.82～+7.24 f7 -5.52～+6.17 ND7 1.48～1.75 R71 -1.86～+19.96 R72 -4.41～-2.78 f8 -12.52～+13.28 ND8 1.52～1.66 R81 -141.75～+6.49 R82 -121.88～+4.37

[0019] wherein f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the object side surface radius of curvature of the first lens, and R12 is the image side surface radius of curvature of the first lens.

[0020] f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the object side surface radius of curvature of the second lens, and R22 is the image side surface radius of curvature of the second lens.

[0021] f3 is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the object side surface radius of curvature of the third lens, and R32 is the image side surface radius of curvature of the third lens.

[0022] f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, R41 is the object side surface radius of curvature of the fourth lens, and R42 is the image side surface radius of curvature of the fourth lens.

[0023] f5 is the focal length of the fifth lens, ND5 is the refractive index of the fifth lens, R51 is the object side surface radius of curvature of the fifth lens, and R52 is the image side surface radius of curvature of the fifth lens.

[0024] f6 is the focal length of the sixth lens, ND6 is the refractive index of the sixth lens, R61 is the object side surface radius of curvature of the sixth lens, and R62 is the image side surface radius of curvature of the sixth lens.

[0025] f7 is the focal length of the seventh lens, ND7 is the refractive index of the seventh lens, R71 is the curvature radius of the object side surface of the seventh lens, and R72 is the curvature radius of the image side surface of the seventh lens;

[0026] f8 is the focal length of the eighth lens, ND8 is the refractive index of the eighth lens, R81 is the curvature radius of the object side surface of the eighth lens, and R82 is the curvature radius of the image side surface of the eighth lens;

[0027] Focal length: "+" indicates that the lens has positive refractive power, "-" indicates that the lens has negative refractive power, and the unit is mm;

[0028] Curvature radius: "+" indicates that the surface is curved to the image side, "-" indicates that the surface is curved to the object side, and the unit is mm.

[0029] Further, in the present application, in order to make the optical system have better performance, we reasonably select the lens material, reasonably distribute the focal lengths of each lens and reasonably optimize the optical system in the design process to correct the aberration of the system, so that the performance of the optical system is optimized, and the ratio of the focal length of each lens to the total focal length of the lens also satisfies the following conditions:

[0030] -3.93≤f1 / f≤-2.86;

[0031] -4.94≤f2 / f≤-3.01;

[0032] 2.31≤f3 / f≤6.85;

[0033] -5.42≤f4 / f≤7.10;

[0034] -10.95≤f5 / f≤2.71;

[0035] -2.88≤f6 / f≤1.39;

[0036] -2.37≤f7 / f≤2.66;

[0037] -5.13≤f8 / f≤5.70;

[0038] In the relationship, f is the total focal length of the optical lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

[0039] Further, in the present application,

[0040] The field of view of the optical lens is FOV, and FOV≥200° is satisfied;

[0041] An aperture of the optical lens is F#, which satisfies F#>=1.9;

[0042] An overall optical length of the optical lens is TTL, which satisfies TTL<=16.0mm;

[0043] An overall focal length of the optical lens is f, which satisfies f>=2.25mm;

[0044] An optical back focal length of the optical lens is OBFL, which satisfies OBFL>=2.47mm.

[0045] Further, the lens satisfies the following relationship in the application:

[0046] IC / TTL>=0.38;

[0047] TTL / f<=7.15;

[0048] OBFL / TTL>=0.15;

[0049] IC / f>=2.39;

[0050] In the relationship, f is the overall focal length of the optical lens, TTL is the overall optical length of the optical lens, OBFL is the optical back focal length of the optical lens, the optical back focal length is the distance from the point closest to the image plane on the image side of the eighth lens to the image plane, and IC is the full image height of the chip matched with the optical lens.

[0051] Further, when any one of the first lens to the eighth lens is aspherical in the application, the aspheric surface of the lens satisfies the following formula:

[0052]

[0053] In the formula, Z is the sag of the lens along the optical axis, k is the conic coefficient of the quadratic surface, gamma is the height of the lens, c is the curvature of the lens, A, B, C, D, E, F, and G are the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order term coefficients of the aspheric polynomial.

[0054] The beneficial effects of the application are:

[0055] The application adopts a combination of multiple pieces of glass and multiple pieces of aspherical plastic, and through the mutual matching of different shapes of lenses and the reasonable distribution of optical powers, the aberration of the optical system can be reduced, the imaging quality of the lens can be improved, the optical performance of the entire lens is good, and the lens has the advantages of large field of view, large aperture, high imaging quality, and high brightness. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 The optical structure of the embodiment 1 of the application is shown in the figure;

[0057] Figure 2 MTF plot for Example 1 of the present application for visible light 0.435-0.656 μm (160 lp / mm);

[0058] Figure 3 Relative intensity plot for Example 1 of the present application for visible light 0.546 μm;

[0059] Figure 4 Optical structure schematic for Example 2 of the present application;

[0060] Figure 5 MTF plot for Example 2 of the present application for visible light 0.435-0.656 μm (160 lp / mm);

[0061] Figure 6 Relative intensity plot for Example 2 of the present application for visible light 0.546 μm;

[0062] Figure 7 Optical structure schematic for Example 3 of the present application;

[0063] Figure 8 MTF plot for Example 3 of the present application for visible light 0.435-0.656 μm (160 lp / mm);

[0064] Figure 9 Relative intensity plot for Example 3 of the present application for visible light 0.546 μm;

[0065] Figure 10 Optical structure schematic for Example 4 of the present application;

[0066] Figure 11 MTF plot for Example 4 of the present application for visible light 0.435-0.656 μm (160 lp / mm);

[0067] Figure 12 Relative intensity plot for Example 4 of the present application for visible light 0.546 μm;

[0068] Figure 13 Optical structure schematic for Example 5 of the present application;

[0069] Figure 14 MTF plot for Example 5 of the present application for visible light 0.435-0.656 μm (160 lp / mm);

[0070] Figure 15 Relative intensity plot for Example 5 of the present application for visible light 0.546 μm;

[0071] Reference signs: L1-first lens, L2-second lens, L3-third lens, L4-fourth lens, L5-fifth lens, L6-sixth lens, L7-seventh lens, L8-eighth lens, ST-aperture stop, G1-filter, S19-imaging plane. DETAILED DESCRIPTION

[0072] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. In the present specification, the expressions first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. The shapes of the spherical surface or the aspherical surface are not limited to the shapes of the spherical surface or the aspherical surface shown in the drawings. The drawings are only examples and are not strictly drawn to scale.

[0073] In the present application, the paraxial region refers to a region near the optical axis. If the lens surface is convex and the position of the convex surface is not limited, 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 limited, it means that the lens surface is concave at least in the paraxial region; if the lens surface is not limited to be convex, concave or flat, it means that the lens surface can be convex, concave or flat. 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 plane is called the image side surface of the lens.

[0074] Unless otherwise defined, all terms (including technical and scientific terms) used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms 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 in the present application.

[0075] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. Based on the embodiments of the present application, all other embodiments obtained by one of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0076] The application provides an optical lens, the surface of a lens adjacent to an object side is an object side surface, the surface of the lens adjacent to an image side is an image side surface, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture stop ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter G1 and an image plane S19 are sequentially arranged from the object side to the image side along an optical axis of the lens, the aperture stop ST is located between the fourth lens L4 and the fifth lens L5, the filter G1 is arranged on the image side surface of the eighth lens L8, and the image plane S19 is arranged on the image side surface of the filter G1.

[0077] Wherein:

[0078] The first lens L1 can have a negative focal length, the object side surface thereof is a convex surface, and the image side surface thereof is a concave surface.

[0079] The second lens L2 can have a negative focal length, the object side surface thereof can be a convex surface or a concave surface, and the image side surface thereof is a concave surface.

[0080] The third lens L3 can have a positive focal length, the object side surface thereof is a convex surface, and the image side surface thereof can be a concave surface or a convex surface.

[0081] The fourth lens L4 can have a positive focal length or a negative focal length, the object side surface thereof can be a convex surface or a concave surface, and the image side surface thereof can be a concave surface or a convex surface.

[0082] The fifth lens L5 can have a positive focal length or a negative focal length, the object side surface thereof is a convex surface, and the image side surface thereof can be a concave surface or a convex surface.

[0083] The sixth lens L6 can have a positive focal length or a negative focal length, the object side surface thereof can be a convex surface or a concave surface, and the image side surface thereof can be a concave surface or a convex surface.

[0084] The seventh lens L7 can have a positive focal length or a negative focal length, the object side surface thereof can be a convex surface or a concave surface, and the image side surface thereof can be a concave surface or a convex surface.

[0085] The eighth lens L8 can have a positive focal length or a negative focal length, the object side surface thereof can be a convex surface or a concave surface, and the image side surface thereof can be a concave surface or a convex surface.

[0086] In the application, the field of view of the optical lens is FOV, and FOV≥200° is met.

[0087] The aperture of the optical lens is F#, and F#≥1.9 is met.

[0088] The total length of the optical lens is TTL, and TTL≤16.0mm is met.

[0089] The total focal length of the optical lens is f, and f≥2.25mm is met.

[0090] An optical back focal length of the optical lens is OBFL, and the optical back focal length satisfies OBFL >= 2.47 mm, and the optical back focal length is a distance from a point closest to an image plane on an image side of the eighth lens L8 to the image plane.

[0091] They also satisfy the following relationship:

[0092] IC / TTL >= 0.38;

[0093] TTL / f <= 7.15;

[0094] OBFL / TTL >= 0.15;

[0095] IC / f >= 2.39;

[0096] IC is a full image height of a chip matched with the optical lens.

[0097] The optical lens provided by the application has the advantages that the lens material can be glass or plastic.

[0098] In the application, when any one of the first lens to the eighth lens is an aspherical surface, the aspherical surface of the lens satisfies the following formula:

[0099]

[0100] In the formula, Z is a sag of the lens along an optical axis, k is a conic coefficient of a quadratic surface, gamma is a height of the lens, c is a curvature of the lens, A, B, C, D, E, F, and G are coefficients of 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

[0101] The following is a specific embodiment according to the above settings of the application, which specifically describes the optical lens of the application.

[0102] The main element symbols in the specific embodiments of the application are shown in Table 1.

[0103] Table 1

[0104] S1 First lens object side surface S8 Fourth lens image side surface S14 Seventh lens image side surface S2 First lens image side surface ST Diaphragm S15 Eighth lens object side surface S3 Second lens object side surface S9 Fifth lens object side surface S16 Eighth lens image side surface S4 Second lens image side surface S10 Fifth lens image side surface S17 Filter object side surface S5 Third lens object side surface S11 Sixth lens object side surface S18 Filter image side surface S6 Third lens image side surface S12 Sixth lens image side surface S19 Imaging surface S7 Fourth lens object side surface S13 Seventh lens object side surface

[0105] The data of the specific embodiments of the application are shown in Table 2.

[0106] Table 2

[0107]

[0108]

[0109] Embodiment 1

[0110] Referring to Figure 1 Fig. 1 is a schematic diagram of the optical structure of the optical lens of the present embodiment. The lens in the present embodiment is sequentially arranged from the object side to the image side along the optical axis of the lens, and comprises:

[0111] The first lens L1 is a spherical glass lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0112] The second lens L2 is an aspherical plastic lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0113] The third lens L3 is an aspherical plastic lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0114] The fourth lens L4 is a spherical glass lens with positive focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;

[0115] The aperture stop ST;

[0116] The fifth lens L5 is an aspherical glass lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;

[0117] The sixth lens L6 is an aspherical glass lens with negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface;

[0118] The seventh lens L7 is an aspherical glass lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;

[0119] The eighth lens L8 is an aspherical plastic lens with negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface;

[0120] The object side surface and the image side surface of the filter G1 are both flat surfaces;

[0121] The imaging surface S19 is a flat surface.

[0122] In the present embodiment, the radius of curvature (unit: mm), the center thickness d (unit: mm), the refractive index (ND), and the Abbe number (VD) of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are shown in Table 1-1.

[0123] Table 1-1

[0124]

[0125] In Table 1-1, the curvature radius represents the bending degree of the lens surface, the positive value represents that the surface bends to the image side, and the negative value represents that the surface bends to the object side; the center thickness represents the center axial distance from the current surface to the next surface, the refractive index represents the deflection ability of the current lens material to light, and the Abbe number represents the dispersion characteristics of the current lens material to light.

[0126] In this embodiment, the aspheric surfaces of the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 can be defined by the above equation of even aspheric surface. Table 1-2 shows the coefficients of the aspheric surfaces of the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8.

[0127] Table 1-2

[0128]

[0129] In this embodiment, the total focal length of the lens is f = 2.32 mm, the aperture value is F# = 1.91, the total image height is IC = 6.2 mm, the field of view angle is DFOV = 200°, the total optical length of the lens is TTL = 16 mm, and the optical back focal length of the lens system is OBFL = 2.51 mm.

[0130] Reference Figure 2 Fig. 4 shows the MTF curves of the lens in this embodiment at different spatial frequencies in the visible light wavelength range of 0.435-0.656 μm. The horizontal axis represents the spatial frequency, and the vertical axis represents the MTF value. As can be seen from the figure, when the spatial frequency is 160 lp / mm, the MTF value of the lens in the full field of view is above 0.5, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, indicating that the optical lens has good imaging quality and good detail resolution ability in both low and high frequency cases.

[0131] Reference Figure 3 Fig. 5 shows the relative luminance curves of the lens in this embodiment at the visible light wavelength of 0.546 μm. As can be seen from the figure, the relative luminance of the lens at the maximum field of view is above 55%, indicating that the optical lens has sufficient light intake, ensuring that the lens can be used even in a relatively dark environment, and the edge of the actual shooting picture will not have a dark corner.

[0132] Embodiment 2

[0133] Reference Figure 4 Fig. 1 shows the optical structure of the optical lens in this embodiment. The lens in this embodiment is sequentially arranged from the object side to the image side along the optical axis of the lens as follows:

[0134] The first lens L1 is a spherical glass lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0135] The second lens L2 is an aspherical plastic lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0136] The third lens L3 is an aspherical plastic lens with positive focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0137] The fourth lens L4 is a spherical glass lens with positive focal power, the object side surface of which is concave, and the image side surface of which is convex;

[0138] The aperture stop ST;

[0139] The fifth lens L5 is an aspherical glass lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0140] The sixth lens L6 is an aspherical plastic lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0141] The seventh lens L7 is an aspherical plastic lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0142] The eighth lens L8 is an aspherical plastic lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0143] The object side surface and the image side surface of the filter G1 are both flat;

[0144] The imaging surface S19 is flat.

[0145] In this embodiment, the curvature radius (unit: mm), the center thickness d (unit: mm), the refractive index (ND) and the Abbe number (VD) of each lens are shown in Table 2-1.

[0146] Table 2-1

[0147]

[0148] In this embodiment 2, the aspherical surfaces of the optical lens can be defined by the above-mentioned even aspherical surface equation, and the aspherical surface parameters are shown in Table 2-2.

[0149] Table 2-2

[0150]

[0151] In this embodiment, the total focal length of the lens is f = 2.44 mm, the aperture value is F# = 1.91, the holographic height is IC = 6.1 mm, the field of view (DFOV) is 200.6°, the total optical length (TTL) of the lens is 16 mm, and the optical back focal length (OBFL) of the lens system is 2.72 mm.

[0152] refer to Figure 5 The figure shows the MTF curves of the lens in this embodiment at different spatial frequencies and fields of view under visible light wavelengths of 0.435-0.656μm. The horizontal axis represents spatial frequency, and the vertical axis represents MTF value. As can be seen from the figure, at a spatial frequency of 160 lp / mm, the MTF value of the lens across the entire field of view is above 0.35. Within the range of 0-160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating that the optical lens has good imaging quality and good detail resolution at both low and high frequencies.

[0153] refer to Figure 6 The figure shows the relative illuminance curve of the lens at 0.546μm visible light in this embodiment. As can be seen from the figure, the relative illuminance at the maximum field of view is above 50%, indicating that the optical lens has sufficient light intake, ensuring that the lens can be used even in relatively dark environments, and there is no vignetting at the edge of the field of view in the actual shooting image.

[0154] Example 3

[0155] Reference Figure 7 As shown, this is a schematic diagram of the optical structure of the optical lens in this embodiment. The main difference between the optical lens in this embodiment 3 and that in embodiment 1 is that: the image-side surface S16 of the eighth lens L8 is convex, the fourth lens L4 is an aspherical plastic lens, and the fifth lens L5 is a spherical glass lens; the optical parameters such as the radius of curvature and thickness of each lens surface are different.

[0156] In this embodiment, the radius of curvature (unit: mm), center thickness d (unit: mm), refractive index (ND), and Abbe constant (VD) of each lens are shown in Table 3-1.

[0157] Table 3-1

[0158]

[0159] In this embodiment 3, the aspherical surfaces of the optical lens can all be defined by the above-mentioned equations for even-order aspherical surfaces, and the aspherical parameters are shown in Table 3-2.

[0160] Table 3-2

[0161]

[0162] In this embodiment, the total focal length of the lens is f = 2.59 mm, the aperture value is F# = 1.91, the holographic height is IC = 6.2 mm, the field of view is DFOV = 200.2°, the total optical length of the lens is TTL = 16 mm, and the optical back focal length of the lens system is OBFL = 2.51 mm.

[0163] refer to Figure 8 The figure shows the MTF curves of the lens in this embodiment at different spatial frequencies and fields of view under visible light wavelengths of 0.435-0.656μm. The horizontal axis represents spatial frequency, and the vertical axis represents MTF value. As can be seen from the figure, at a spatial frequency of 160 lp / mm, the MTF value of the lens across the entire field of view is above 0.4. Within the range of 0-160 lp / mm, the MTF curve decreases smoothly and evenly from the center to the edge of the field of view, indicating that the optical lens has good imaging quality and good detail resolution at both low and high frequencies.

[0164] refer to Figure 9 The figure shows the relative illuminance curve of the lens at 0.546μm visible light in this embodiment. As can be seen from the figure, the relative illuminance at the maximum field of view is above 45%, indicating that the optical lens has sufficient light intake, ensuring that the lens can be used even in dim environments, and there is no vignetting at the edge of the field of view in the actual shot.

[0165] Example 4

[0166] Reference Figure 10 The diagram shown is a schematic representation of the optical structure of the lens in this embodiment. In this embodiment, the lens is arranged sequentially from the object side to the image side along the lens optical axis:

[0167] The first lens L1 is a spherical glass lens with negative optical power, its object side is convex and its image side is concave.

[0168] The second lens L2 is an aspherical plastic lens with negative optical power, its object side is convex and its image side is concave.

[0169] The third lens L3 is a spherical glass lens with positive optical power, and its object side is convex and its image side is convex.

[0170] The fourth lens L4 is an aspherical glass lens with negative optical power. Its object side is concave and its image side is convex.

[0171] Aperture stop ST;

[0172] The fifth lens L5 is an aspherical glass lens with positive optical power. Its object side is convex and its image side is concave.

[0173] The sixth lens L6 is a non-spherical plastic lens with negative focal power, the object side surface of which is convex, and the image side surface of which is concave;

[0174] The seventh lens L7 is a non-spherical plastic lens with positive focal power, the object side surface of which is convex, and the image side surface of which is convex;

[0175] The eighth lens L8 is a non-spherical plastic lens with negative focal power, the object side surface of which is concave, and the image side surface of which is concave;

[0176] The filter G1 has a flat object side surface and a flat image side surface;

[0177] The imaging surface S19 is flat.

[0178] In this embodiment, the curvature radius (unit: mm), the center thickness d (unit: mm), the refractive index (ND) and the Abbe number (VD) of each lens are shown in Table 4-1.

[0179] Table 4-1

[0180]

[0181] In this embodiment 4, the non-spherical surfaces of the optical lens can be defined by the above equation of even non-spherical surface, and the non-spherical surface parameters are shown in Table 4-2.

[0182] Table 4-2

[0183]

[0184] In this embodiment, the total focal length of the lens is f = 2.26 mm, the aperture value is F# = 1.90, the full image height is IC = 6.2 mm, the field of view angle is DFOV = 200.6°, the total optical length of the lens is TTL = 16 mm, and the optical back focal length of the lens system is OBFL = 2.48 mm.

[0185] Reference Figure 11 The MTF curves of the lens in this embodiment at different spatial frequencies in the visible light wavelength range of 0.435-0.656 μm are shown in FIG. 6. In the figure, the horizontal axis represents the spatial frequency, and the vertical axis represents the MTF value. As can be seen from the figure, when the spatial frequency is 160 lp / mm, the MTF value of the full field of view of the lens is above 0.28, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, which indicates that the optical lens has good imaging quality and good detail resolution capability in both low frequency and high frequency cases.

[0186] Reference Figure 12The relative luminance curve of the visible light 0.546 μm of the lens in the embodiment is shown. As can be seen from the figure, the relative luminance at the maximum field of view is above 45%, which indicates that the amount of light entering the optical lens is sufficient, thereby ensuring that the lens can be used even in a relatively dark environment, and the edge of field of view of the actual shot picture will not have a dark corner.

[0187] Embodiment 5

[0188] Referring to Figure 13 The optical structure schematic diagram of the optical lens in the embodiment is shown. The lens in the embodiment is sequentially provided from the object side to the image side along the optical axis of the lens as follows:

[0189] The first lens L1 is a spherical glass lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0190] The second lens L2 is a non-spherical plastic lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0191] The third lens L3 is a non-spherical plastic lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0192] The fourth lens L4 is a spherical glass lens with positive focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;

[0193] The aperture stop ST;

[0194] The fifth lens L5 is a non-spherical plastic lens with negative focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;

[0195] The sixth lens L6 is a non-spherical glass lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;

[0196] The seventh lens L7 is a non-spherical plastic lens with negative focal power, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;

[0197] The eighth lens L8 is a non-spherical plastic lens with positive focal power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0198] The object side surface and the image side surface of the filter G1 are both flat surfaces;

[0199] The imaging surface S19 is a flat surface.

[0200] In the embodiment, the curvature radius (unit: mm), the center thickness d (unit: mm), the refractive index (ND) and the Abbe number (VD) of each lens are shown in Table 5-1.

[0201] Table 5-1

[0202]

[0203] In this embodiment 5, the aspheric surfaces of the optical lens can be defined by the above equation of even aspheric surface, and the aspheric surface parameters are shown in Table 5-2

[0204] Table 5-2

[0205]

[0206] In this embodiment, the total focal length of the lens is f = 2.33 mm, the aperture value is F# = 1.91, the total image height is IC = 6.2 mm, the field of view angle is DFOV = 200.1°, the total optical length of the lens is TTL = 16 mm, and the optical back focal length of the lens system is OBFL = 2.51 mm.

[0207] Reference Figure 14 Fig. 6 shows the MTF curves of the lens in this embodiment at different spatial frequencies in each field of view at the visible wavelength of 0.435-0.656 μm. In the figure, the horizontal axis represents the spatial frequency, and the vertical axis represents the MTF value. As can be seen from the figure, when the spatial frequency is 160 lp / mm, the MTF value of the lens in the full field of view is above 0.45, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, which indicates that the optical lens has good imaging quality and good detail resolution capability in both low and high frequency cases.

[0208] Reference Figure 15 Fig. 7 shows the relative luminance curve of the lens in this embodiment at the visible light of 0.546 μm. As can be seen from the figure, the relative luminance at the maximum field of view is above 55%, which indicates that the optical lens has sufficient light input, ensuring that the lens can be used even in a relatively dark environment, and the edge of the actual shooting picture will not have a dark corner.

[0209] It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, and the present application also intends to include these modifications and improvements.

Claims

1. An optical lens, characterized in that: Set sequentially from the object side to the image side along the lens optical axis: A first lens, the first lens having negative optical power; A second lens, the second lens having negative optical power; A third lens, wherein the third lens has positive optical power; A fourth lens, which has a positive optical power or a negative optical power; Aperture stop; The fifth lens has either positive or negative optical power; The sixth lens has a positive optical power or a negative optical power; The seventh lens has either positive or negative optical power; The eighth lens has either positive or negative optical power; The field of view of the optical lens is FOV, which satisfies FOV≥200°; The aperture of the optical lens is F#, which satisfies F#≥1.

9.

2. An optical lens according to claim 1, characterized in that: The total optical length of the optical lens is TTL, which satisfies TTL≤16.0mm.

3. An optical lens according to claim 1, characterized in that: The total focal length of the optical lens is f, which satisfies f≥2.25mm.

4. An optical lens according to claim 1, characterized in that: The optical back focal length of the optical lens is OBFL, which satisfies OBFL≥2.47mm.

5. An optical lens according to claim 1, characterized in that: The lens also satisfies the following relationship: IC / TTL ≥ 0.38; TTL / f≤7.15; OBFL / TTL ≥ 0.15; IC / f ≥ 2.39; In the formula, f is the total focal length of the optical lens, TTL is the total optical length of the optical lens, OBFL is the optical back focal length of the optical lens, and IC is the full image height of the chip paired with the optical lens.

6. An optical lens according to claim 1, characterized in that: The lens satisfies the following relationship: The lens satisfies the following relationship: -3.93≤f1 / f≤-2.86; -4.94≤f² / f≤-3.01; 2.31≤f3 / f≤6.85; -5.42≤f4 / f≤7.10; -10.95≤f5 / f≤2.71; -2.88≤f6 / f≤1.39; -2.37≤f7 / f≤2.66; -5.13≤f8 / f≤5.70; In the formula, f is the total focal length of the optical lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

7. An optical lens according to claim 1, characterized in that: The focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens are respectively -9.11 to -6.53, -11.51 to -6.98, +5.22 to +17.74, -12.27 to +16.47, -25.49 to +6.56, -6.52 to +3.24, -5.52 to +6.17, and -12.52 to +13.

28. A "+" sign indicates that the lens has positive optical power, and a "-" sign indicates that the lens has negative optical power. The unit of focal length is mm.

8. An optical lens according to claim 1, characterized in that: The refractive index ranges of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens and eighth lens are 1.70~1.85, 1.52~1.56, 1.62~1.72, 1.52~1.79, 1.43~1.65, 1.43~1.90, 1.48~1.75 and 1.52~1.66 respectively.

9. An optical lens according to claim 1, characterized in that: The ranges of the object surface radii of curvature for the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens are +12.13 to +13.21, +1.50 to +2.50, +2.85 to +6.54, -5.70 to -2.66, +2.27 to +2.99, -27.48 to +24.95, -1.86 to +19.96, and -141.75 to +6.49, respectively. The image-side surface curvature radii of the first, second, third, fourth, fifth, sixth, seventh, and eighth lenses, respectively, range from +3.75 to +4.27, +0.96 to +1.45, -10.99 to +27.94, -4.82 to -3.06, -130.95 to +12.32, -2.82 to +7.24, -4.41 to -2.78, and -121.88 to +4.

37. In this context, "+" indicates that the surface bends towards the image plane, and "-" indicates that the surface bends towards the object plane. The unit of radius of curvature is mm.

10. An optical lens according to claim 1, characterized in that: Also set along the lens optical axis: A filter, wherein the filter is disposed on the image-side surface of the eighth lens; An imaging surface is disposed on the image-side surface of the filter; The first lens is a glass lens, and the second, third, fourth, fifth, sixth, seventh, and eighth lenses are glass lenses or plastic lenses.

Images