A wide-angle lens

Abstract

The invention discloses a wide-angle lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from an object plane to an image plane along an optical axis; the first lens, the second lens, the fourth lens and the sixth lens are negative focal lenses, the third lens, the fifth lens and the seventh lens are positive focal lenses; the focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the focal length of the fifth lens is f6. The focal length of the fifth lens is f4, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, and the focal length of the wide-angle lens is f, wherein: 1.1≤|f1 / f|≤2.4;|f2 / f|≥4.2; 0.7≤|f3 / f|≤2.85; 2.5≤|f4 / f|; 0.6≤|f5 / f|≤2.9; 0.33≤|f6 / f|≤1.87; 0.55≤|f7 / f|≤2.73. The wide-angle lens provided by the present invention ensures that the ultra-large light flux is met at a low cost and the monitoring requirements under low illumination conditions are realized.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of optical devices, and in particular to a wide-angle lens. Background Art

[0002] As the security monitoring field becomes increasingly high-definition, networked, and intelligent, the application scope of cameras is becoming more and more extensive. Many places with poor monitoring conditions and dim light also require the installation of multi-functional cameras, especially low-light high-definition cameras, to meet the needs of 24-hour monitoring. For low-light environments such as night, if the camera does not collect enough light, the picture will be very dark, affecting the clarity. For improving the low-light performance of cameras, ultra-large aperture lenses are one of the key technologies, so it is necessary to develop a large aperture wide-angle lens to solve the above problems. Summary of the invention

[0003] The present invention provides a wide-angle lens to realize a wide-angle lens with a large aperture, thereby ensuring that an ultra-large light flux is met at a low cost and realizing monitoring requirements under low illumination conditions.

[0004] In a first aspect, an embodiment of the present invention provides a wide-angle lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from an object plane to an image plane along an optical axis;

[0005] The first lens is a negative power lens, the second lens is a negative power lens, the third lens is a positive power lens, the fourth lens is a negative power lens, the fifth lens is a positive power lens, the sixth lens is a negative power lens, and the seventh lens is a positive power lens;

[0006] The focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, and the focal length of the wide-angle lens is f, wherein:

[0007] 1.1≤|f1 / f|≤2.4; |f2 / f|≥4.2; 0.7≤|f3 / f|≤2.85; 2.5≤|f4 / f|; 0.6≤|f5 / f|≤2.9; 0.33≤|f6 / f|≤1.87; 0.55≤|f7 / f|≤2.73.

[0008] Optionally, the third lens is a glass spherical lens; and the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all plastic aspherical lenses.

[0009] Optionally, the wide-angle lens further includes a stop, and the stop is arranged in the light path between the fourth lens and the fifth lens.

[0010] Optionally, the refractive index of the second lens is n2; the refractive index of the third lens is n3, and the Abbe number is v3; wherein:

[0011] 1.43≤n2≤1.75;n3≥1.65,22≤v3≤56.

[0012] Optionally, a clear aperture of the first lens is D1, and a distance from an optical axis center of the image-side surface of the seventh lens to an image plane is BFL, wherein |D1 / BFL|≥1.8.

[0013] Optionally, the air gap between the fifth lens and the sixth lens is TH56, the air gap between the sixth lens and the seventh lens is TH67, and the distance from the optical axis center of the object side of the first lens to the image plane is TTL, wherein TH56 / TTL≥0, and / or TH67 / TTL≥0.

[0014] Optionally, the fourth lens is a meniscus lens.

[0015] Optionally, the distance from the optical axis center of the image side surface of the seventh lens to the image plane is BFL, and the distance from the optical axis center of the object side surface of the first lens to the image plane is TTL, wherein 0.05≤BFL / TTL≤0.88.

[0016] Optionally, the aperture number of the wide-angle lens is F, where 0.8≤F≤1.2.

[0017] Optionally, the field of view of the wide-angle lens is FOV, where 100°≤FOV≤120°.

[0018] The wide-angle lens provided in the embodiment of the present invention ensures the balance of the incident angles of the front and rear lens groups of the wide-angle lens under the premise of low cost by reasonably setting the number of lenses in the wide-angle lens, the focal power of each lens, and the relative relationship between the focal lengths of each lens, and reduces the sensitivity of the lens, and corrects the aberration at a super-large aperture to ensure that the wide-angle lens has a high resolution, thereby ensuring that the wide-angle lens meets the super-large light throughput under the premise of a small aperture number, and realizes the high-definition monitoring requirements under low illumination conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of a wide-angle lens provided by an embodiment of the present invention;

[0020] Figure 2 A spherical aberration curve diagram of a wide-angle lens provided by an embodiment of the present invention;

[0021] Figure 3 A light fan diagram of a wide-angle lens provided by an embodiment of the present invention;

[0022] Figure 4 A visible light point diagram of a wide-angle lens provided by an embodiment of the present invention;

[0023] Figure 5 A spot diagram of a wide-angle lens provided by an embodiment of the present invention at a wavelength of 436nm;

[0024] Figure 6 A field curvature distortion diagram of a wide-angle lens provided by an embodiment of the present invention;

[0025] Figure 7 This is an MTF diagram of a wide-angle lens provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0027] Figure 1 A schematic diagram of the structure of a wide-angle lens provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the wide-angle lens provided by the embodiment of the present invention includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160 and a seventh lens 170 which are arranged in sequence from the object plane to the image plane along the optical axis; the first lens 110 is a negative power lens, the second lens 120 is a negative power lens, the third lens 130 is a positive power lens, the fourth lens 140 is a negative power lens, the fifth lens 150 is a positive power lens, the sixth lens 160 is a negative power lens, and the seventh lens 170 is a positive power lens ; The focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, and the focal length of the wide-angle lens is f, where: 1.1≤|f1 / f|≤2.4; |f2 / f|≥4.2; 0.7≤|f3 / f|≤2.85; 2.5≤|f4 / f|; 0.6≤|f5 / f|≤2.9; 0.33≤|f6 / f|≤1.87; 0.55≤|f7 / f|≤2.73.

[0028] Exemplarily, the focal length is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. The focal length can be used to characterize a certain refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group). In the wide-angle lens provided in this embodiment, each lens can be fixed to a lens barrel ( Figure 1 In the optical system (not shown), the first lens 110 is set as a negative power lens to control the incident angle of light in the optical system; the second lens 120, the fourth lens 140 and the sixth lens 160 are negative power lenses; the third lens 130, the fifth lens 150 and the seventh lens 170 are positive power lenses; the fifth lens 150, the sixth lens 160 and the seventh lens 170 are used to correct off-axis aberrations, including field curvature, coma, astigmatism and other aberrations. The power of the entire wide-angle lens is distributed according to a certain ratio to ensure the balance of the incident angles of the front and rear lens groups, so as to reduce the sensitivity of the lens and improve the possibility of production.

[0029] Further, the focal length f1 of the first lens 110, the focal length f2 of the second lens 120, the focal length f3 of the third lens 130, the focal length f4 of the fourth lens 140, the focal length f5 of the fifth lens 150, the focal length f6 of the sixth lens 160, the focal length f7 of the seventh lens 170 and the focal length f of the wide-angle lens are set to meet the following conditions: 1.1≤|f1 / f|≤2.4;|f2 / f|≥4.2;0.7≤|f3 / f|≤2.85;2.5≤|f4 / f|;0.6≤|f5 / f|≤2.9;0.33≤|f6 / f|≤1.87;0.55≤|f7 / f|≤2.73. By rationally allocating the focal lengths of the lenses, it is beneficial to correct aberrations at ultra-large apertures, ensuring that the lens has a high resolution.

[0030] The wide-angle lens provided in the embodiment of the present invention ensures the balance of the incident angles of the front and rear lens groups of the wide-angle lens under the premise of low cost by reasonably setting the number of lenses in the wide-angle lens, the focal power of each lens, and the relative relationship between the focal lengths of each lens, and reduces the sensitivity of the lens, and corrects the aberration at a super-large aperture to ensure that the wide-angle lens has a high resolution, thereby ensuring that the wide-angle lens meets the super-large light throughput under the premise of a small aperture number, and realizes the high-definition monitoring requirements under low illumination conditions.

[0031] Optionally, the third lens 130 is a glass spherical lens, and the first lens 110, the second lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all plastic aspherical lenses.

[0032] Among them, the third lens 130 is a glass spherical lens, and the first lens 110, the second lens 120, the fourth lens 140, the fifth lens 150, the sixth lens 160 and the seventh lens 170 are all plastic aspherical lenses, and the aspherical lenses play a role in correcting all high-order aberrations. Since the cost of lenses made of plastic material is much lower than that of lenses made of glass material, in the wide-angle lens provided by the embodiment of the present invention, by setting 6 plastic aspherical lenses, the image quality is good and the cost is low. And because the two types of materials have a mutual compensation effect, it can be ensured that the wide-angle lens can still be used normally in high and low temperature environments.

[0033] Continue to refer Figure 1 Optionally, the wide-angle lens provided in the embodiment of the present invention further includes an aperture 180 , and the aperture 180 is disposed in the optical path between the fourth lens 140 and the fifth lens 150 .

[0034] Among them, by arranging the aperture 180 in the light path between the fourth lens 140 and the fifth lens 150, the propagation direction of the light beam can be adjusted, and the incident angle of the light beam can be adjusted, which is beneficial to improving the imaging quality.

[0035] Optionally, the refractive index of the second lens 120 is n2; the refractive index of the third lens 130 is n3, and the Abbe number is v3; wherein, 1.43≤n2≤1.75; n3≥1.65, 22≤v3≤56.

[0036] Among them, the refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium. It is mainly used to describe the material's ability to refract light. Different materials have different refractive indices. The Abbe number is an index used to represent the dispersion ability of a transparent medium. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less the dispersion of the medium, the larger the Abbe number. In this way, by matching the refractive index and Abbe number of each lens in the wide-angle lens, the balance of the incident angle of the front and rear lens groups is ensured to reduce the sensitivity of the lens and improve the possibility of production; at the same time, it is conducive to achieving higher pixel resolution and larger aperture.

[0037] Optionally, the first lens 110 has a light aperture of D1, and the distance from the center of the optical axis of the image-side surface of the seventh lens 170 to the image plane is BFL, wherein |D1 / BFL|≥1.8.

[0038] Among them, the distance from the center of the optical axis of the image-side surface of the seventh lens 170 to the image plane can be understood as the back focus (In air) of the wide-angle lens. By reasonably setting the maximum light aperture D1 of the first lens 110 and the back focus BFL of the wide-angle lens to satisfy |D1 / BFL|≥1.8, the entire wide-angle lens can be kept compact while meeting the light intake of the wide-angle lens.

[0039] Optionally, the air gap between the fifth lens 150 and the sixth lens 160 is TH56, the air gap between the sixth lens 160 and the seventh lens 170 is TH67, and the distance from the optical axis center of the object side of the first lens 110 to the image plane is TTL, wherein TH56 / TTL≥0, and / or TH67 / TTL≥0.

[0040] Among them, the distance from the optical axis center of the object side of the first lens 110 to the image plane can be understood as the total length of the wide-angle lens (In air). By setting TH56 / TTL≥0 and / or TH67 / TTL≥0, the total length of the air space is reasonably constrained, so that the lens structure is more compact, and the effective focal length of the wide-angle lens and the total length of the wide-angle lens are still within a reasonable range while achieving a large aperture.

[0041] Exemplarily, TH56 / TTL=0 and / or TH67 / TTL=0 are set, and the fifth lens 150 and the sixth lens 160 can be combined into a cemented lens by gluing the image side surface of the fifth lens 150 with the object side surface of the sixth lens 160, and / or the image side surface of the sixth lens 160 with the object side surface of the seventh lens 170, and / or the sixth lens 160 and the seventh lens 170 can be combined into a cemented lens; the use of a cemented lens can effectively reduce the air gap between the fifth lens 150 and the sixth lens 160, and / or the air gap between the sixth lens 160 and the seventh lens 170, thereby reducing the total length of the lens. In addition, the cemented lens can be used to minimize or eliminate chromatic aberration, so that various aberrations of the wide-angle lens can be fully corrected, and the resolution can be improved under the premise of compact structure, and the optical properties such as distortion and CRA can be optimized; and the light loss caused by reflection between lenses can be reduced, and the illumination can be improved, thereby improving the image quality and the clarity of the lens imaging. In addition, the use of cemented lenses can also reduce the number of components between the two lenses, simplify the assembly process during the lens manufacturing process, reduce costs, and reduce the tolerance sensitivity of the lens unit due to tilt / eccentricity caused during the assembly process.

[0042] Optionally, the fourth lens 140 is a meniscus lens.

[0043] The meniscus lens is composed of two spherical surfaces with small curvature radii and little numerical difference. Setting the fourth lens 140 as a meniscus lens helps to correct field curvature.

[0044] Optionally, the distance from the optical axis center of the image-side surface of the seventh lens 170 to the image plane is BFL, and the distance from the optical axis center of the object-side surface of the first lens 110 to the image plane is TTL, wherein 0.05≤BFL / TTL≤0.88.

[0045] Among them, the distance BFL from the optical axis center of the image side surface of the seventh lens 170 to the image plane can be understood as the back focus of the wide-angle lens, and the distance TTL from the optical axis center of the object side surface of the first lens 110 to the image plane can be understood as the total length of the wide-angle lens. By reasonably setting the relationship between the back focus of the wide-angle lens and the total length of the wide-angle lens, the entire wide-angle lens can be ensured to have a compact structure and a high degree of integration.

[0046] Optionally, the aperture number of the wide-angle lens provided in the embodiment of the present invention is F, where 0.8≤F≤1.2.

[0047] The wide-angle lens provided in the embodiment of the present invention is a large-aperture wide-angle lens, which can meet ultra-large throughput and is suitable for monitoring needs under low-illumination conditions.

[0048] Optionally, the field of view of the wide-angle lens provided in the embodiment of the present invention is FOV, where 100°≤FOV≤120°.

[0049] The wide-angle lens provided in the embodiment of the present invention is a wide-angle lens with a relatively large field of view, which meets the requirement of a large field of view.

[0050] The wide-angle lens provided in the embodiment of the present invention ensures the balance of the incident angles of the front and rear lens groups of the wide-angle lens at a low cost by reasonably allocating the focal length, refractive index, Abbe number, etc. of each lens, reduces the sensitivity of the lens, and corrects the aberration at a super-large aperture to ensure that the wide-angle lens has a high resolution, thereby ensuring that the wide-angle lens meets the super-large light throughput under the premise of a small aperture number, and realizes the high-definition monitoring requirements under low illumination conditions.

[0051] As a feasible implementation, the curvature radius, thickness, material and K factor of each lens surface in the wide-angle lens are described below.

[0052] Table 1 Design values ​​of curvature radius, thickness, material and K factor of wide-angle lens

[0053]

[0054]

[0055] Continue to refer Figure 1, the wide-angle lens provided in the embodiment of the present invention comprises a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160 and a seventh lens 170 arranged in sequence from the object plane to the image plane along the optical axis. Table 1 shows the optical physical parameters such as the radius of curvature, thickness and material of each lens in the wide-angle lens provided in the embodiment. Among them, the surface number is numbered according to the surface order of each lens, for example, "1" represents the object surface of the first lens 110, "2" represents the image surface of the first lens 110, "10" represents the object surface of the fifth lens 150, "11" represents the image surface of the fifth lens 150, and so on; the radius of curvature represents the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; the thickness represents the central axial distance from the current surface to the next surface, and the units of the radius of curvature and thickness are both millimeters (mm).

[0056] On the basis of the above implementation, optionally, the third lens 130 is a glass spherical lens, and the first lens 110, the second lens 120, the fourth lens 140, the fifth lens 150, the sixth lens 160 and the seventh lens 170 are all plastic aspherical lenses. The wide-angle lens provided in the embodiment of the present invention also includes an aperture 180 (STO). By adding the aperture 180, the propagation direction of the light beam can be adjusted, which is beneficial to improving the imaging quality. The aperture 180 can be located in the optical path between the fourth lens 140 and the fifth lens 150, but the embodiment of the present invention does not limit the specific setting position of the aperture 180.

[0057] The aspherical surface shape equation Z of the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160 and the seventh lens 170 satisfies:

[0058]

[0059] Wherein, Z is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of y along the optical axis; c = 1 / R, R represents the paraxial curvature radius of the mirror surface; K is the cone coefficient; A, B, C, D, E, and F are high-order aspheric coefficients, where the units of Z, R, and y are all mm.

[0060] Exemplarily, Table 2 describes in detail the aspheric coefficients of each lens in this embodiment in a feasible implementation manner.

[0061] Table 2 Aspheric coefficients in wide-angle lenses

[0062]

[0063]

[0064] Among them, -3.82E-03 means that the coefficient A of the face number 1 is -3.82*10 -3 , and so on.

[0065] The wide-angle lens provided in this embodiment achieves the following technical indicators:

[0066] Entrance diameter: N = 3.65;

[0067] Aperture: F=1.0;

[0068] TTL / BFL=5.3;

[0069] Field of view: 2w ≥ 100°;

[0070] Resolution: Compatible with 5-megapixel high-resolution CCD or CMOS cameras.

[0071] Furthermore, Figure 2 A spherical aberration curve diagram of a wide-angle lens provided by an embodiment of the present invention, such as Figure 2 As shown, the spherical aberration of the wide-angle lens at different wavelengths (0.486 μm, 0.588 μm and 0.656 μm) is within 0.05 mm, and the curves at different wavelengths are relatively concentrated, indicating that the axial aberration of the wide-angle lens is very small. Therefore, it can be seen that the wide-angle lens provided by the embodiment of the present invention can correct the aberration well.

[0072] Figure 3 A light fan diagram of a wide-angle lens provided by an embodiment of the present invention, such as Figure 3 As shown, the imaging range of different wavelengths of light (0.486μm, 0.588μm and 0.656μm) at different field angles of the wide-angle lens is all within 30μm and the curves are very concentrated, ensuring that the aberrations in different field areas are small, which means that the wide-angle lens can better correct the aberrations of the optical system.

[0073] Figure 4 The present invention provides a visible light spot diagram of a wide-angle lens, wherein the spot diagram is one of the most commonly used evaluation methods in modern optical design. The spot diagram refers to a diffuse pattern formed by many light rays emitted by a point light source after passing through an optical system, where the intersection points of the light rays with the image plane are no longer concentrated at the same point due to aberration, but are scattered in a certain range. Figure 4As shown, the wide-angle lens provided by the embodiment of the present invention has relatively concentrated diffusion patterns of visible light of different wavelengths (0.4861μm, 0.5876μm and 0.6563μm) in each field of view, and the distribution is relatively uniform. There is no phenomenon that the diffusion pattern in a certain field of view is separated up and down with the wavelength, indicating that there is no obvious purple edge. At the same time, the root mean square radius values ​​(RMSradius) of visible light of different wavelengths (0.4861μm, 0.5876μm and 0.6563μm) at each field of view position of the wide-angle lens are 1.402mm, 2.022mm, 2.420mm, 2.305mm, 2.398mm and 2.460mm respectively, indicating that the RMS radius of each field of view is less than 2.5μm, which means that the wide-angle lens has lower chromatic aberration and aberration in the full field of view, solves the purple edge problem of imaging in the visible light band, and can achieve high-resolution imaging.

[0074] Figure 5 A spot diagram of a wide-angle lens provided by an embodiment of the present invention at a wavelength of 436 nm is shown in FIG. Figure 5 As shown, the wide-angle lens provided by the embodiment of the present invention has a relatively concentrated diffusion pattern of light with a wavelength of 436nm in each field of view, and the distribution is relatively uniform. There is no phenomenon that the diffusion pattern in a certain field of view is separated up and down with the wavelength, indicating that there is no obvious purple edge. At the same time, the root mean square radius values ​​(RMSradius) of the light with a wavelength of 436μm at each field of view of the wide-angle lens are 6.533mm, 6.957mm, 6.835mm, 7.007mm, 6.877mm and 7.223mm, respectively, indicating that the wide-angle lens also performs better aberration and chromatic aberration correction under shorter wavelength visible light, solves the purple edge problem of imaging in the visible light band, and can achieve high-resolution imaging.

[0075] Figure 6 A field curvature distortion diagram of a wide-angle lens provided by an embodiment of the present invention, such as Figure 6 As shown, the wide-angle lens provided by the embodiment of the present invention has a small field curvature, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; the imaging distortion is small, meeting the requirement of low distortion.

[0076] Figure 7 The MTF diagram of a wide-angle lens provided by an embodiment of the present invention is as follows: Figure 7 As shown, the transfer functions at 160 line pairs / mm in the MTF curve are basically above 0.4, and the image quality is high, meeting the resolution requirement of 5 million pixels.

[0077] In summary, the wide-angle lens provided by the embodiment of the present invention has the advantages of large aperture, high image quality and no obvious purple fringing. The design adopts a 7-piece structure, which can achieve the 5MP image quality requirement at a low cost. The glass-plastic hybrid structure can meet the requirement of no focus deviation in an environment of -30℃-80℃.

[0078] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A wide-angle lens, characterized in that: It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from the object plane to the image plane along the optical axis; The first lens is a negative power lens, the second lens is a negative power lens, the third lens is a positive power lens, the fourth lens is a negative power lens, the fifth lens is a positive power lens, the sixth lens is a negative power lens, and the seventh lens is a positive power lens; The focal length of the first lens is f1, the focal length of the second lens is f2, the focal length of the third lens is f3, the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, the focal length of the sixth lens is f6, the focal length of the seventh lens is f7, and the focal length of the wide-angle lens is f, wherein: 1.1≤|f1 / f|≤2.4; |f2 / f|≥4.2; 0.7≤|f3 / f|≤2.85; 2.5≤|f4 / f|; 0.6≤|f5 / f|≤2.9; 0.33≤|f6 / f|≤1.87; 0.55≤|f7 / f|≤2.73; The clear aperture of the first lens is D1, and the distance from the optical axis center of the image side surface of the seventh lens to the image plane is BFL, wherein |D1 / BFL|≥1.8; The fourth lens is a meniscus lens.

2. The wide-angle lens according to claim 1, characterized in that: The third lens is a glass spherical lens; the first lens, the second lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all plastic aspherical lenses.

3. The wide-angle lens according to claim 1, characterized in that: The wide-angle lens further includes a stop disposed in an optical path between the fourth lens and the fifth lens.

4. The wide-angle lens according to claim 1, characterized in that: The refractive index of the second lens is n2; the refractive index of the third lens is n3, and the Abbe number is v3; wherein: 1.43≤n2≤1.75;n3≥1.65,22≤v3≤56.

5. The wide-angle lens according to claim 1, characterized in that: The air interval from the fifth lens to the sixth lens is TH56, the air interval from the sixth lens to the seventh lens is TH67, and the distance from the optical axis center of the object side of the first lens to the image plane is TTL, wherein TH56 / TTL≥0, and / or TH67 / TTL≥0.

6. The wide-angle lens according to claim 1, characterized in that: The distance from the optical axis center of the image side surface of the seventh lens to the image plane is BFL, and the distance from the optical axis center of the object side surface of the first lens to the image plane is TTL, wherein 0.05≤BFL / TTL≤0.

88.

7. The wide-angle lens according to claim 1, characterized in that: The aperture number of the wide-angle lens is F, wherein 0.8≤F≤1.

2.

8. The wide-angle lens according to claim 1, characterized in that: The field of view of the wide-angle lens is FOV, wherein 100°≤FOV≤120°.

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