wide-angle lens

Abstract

The present application relates to a kind of wide-angle lenses, first lens, second lens, third lens, diaphragm, fourth lens, fifth lens and sixth lens are sequentially arranged from object side to image side direction and consist of;Wherein, the first surface, second surface of first lens, fifth lens and sixth lens are odd non-spherical surface, the surface of each lens is spherical surface.The present application overcomes the clearness of existing wide-angle lens, the small size and the small size of the shortcoming of distortion, by specially designing lens shape, refractive power, radius of curvature, center thickness, air gap and other parameters, and by three non-spherical surface lenses and other three spherical surface lenses, it has the advantages of good clarity, small distortion and small size.

Description

Technical Field

[0001] This invention relates to a wide-angle lens, which is used in the field of optical imaging. Background Technology

[0002] With continuous economic development, wide-angle lenses have been widely used in security monitoring, smart homes, vehicle monitoring, and binocular video stitching. However, most wide-angle lenses currently on the market are all-glass lenses or composed of four or more glass elements, and their optical distortion is relatively large (about 20%), resulting in significant distortion around the edges of the image during imaging. This makes it impossible to balance sharpness, distortion, and cost (as shown in the low-distortion wide-angle lens disclosed in CN207502801U), and their size (aperture) is approximately 16mm. Therefore, providing a wide-angle lens with good sharpness, low distortion, small size, and low cost has become an urgent priority. Summary of the Invention

[0003] To overcome the shortcomings of existing wide-angle lenses, which cannot balance sharpness, distortion, and small size, this invention provides a wide-angle lens that, through specially designed parameters such as lens shape, optical power, radius of curvature, center thickness, and air gap, and through the cooperation of three aspherical lenses with three other spherical lenses, has the advantages of good sharpness, low distortion, and small size.

[0004] The technical solution of the present invention is as follows:

[0005] A wide-angle lens comprises a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from the object side to the image side; wherein the first and second surfaces of the first lens, the fifth lens, and the sixth lens are odd-order aspherical surfaces, and all surfaces of the remaining lenses are spherical surfaces.

[0006] The first lens is a negative power lens, with both the first and second surfaces being concave.

[0007] The second lens is a positive power lens, with both the first and second surfaces being convex.

[0008] The third lens is a negative power lens, with both the first and second surfaces being concave.

[0009] The fourth lens is a positive power lens, with both its first and second surfaces being convex.

[0010] The fifth lens is a positive power lens, with both its first and second surfaces being convex.

[0011] The sixth lens is a negative power lens, with a concave first surface and a convex second surface;

[0012] The radius of curvature of the first surface of the first lens is -7.461 to -7.834 mm, and the radius of curvature of the second surface is 1.767 to 1.855 mm.

[0013] The radius of curvature of the first surface of the second lens is 3.591–3.770 mm, and the radius of curvature of the second surface is -20.435–-21.457 mm.

[0014] The radius of curvature of the first surface of the third lens is -7.133 to -7.490 mm, and the radius of curvature of the second surface is 7.784 to 8.173 mm.

[0015] The radius of curvature of the first surface of the fourth lens is 4.248–4.460 mm, and the radius of curvature of the second surface is -3.609–-3.790 mm.

[0016] The radius of curvature of the first surface of the fifth lens is 13.151–13.808 mm, and the radius of curvature of the second surface is -1.267–-1.330 mm.

[0017] The radius of curvature of the first surface of the sixth lens is -0.812 to -0.853 mm, and the radius of curvature of the second surface is -1.503 to -1.578 mm.

[0018] The center thickness of the first lens is 1.463–1.536 mm.

[0019] The center thickness of the second lens is 1.596–1.676 mm.

[0020] The center thickness of the third lens is 0.784–0.823 mm.

[0021] The center thickness of the fourth lens is 2.303–2.418 mm.

[0022] The center thickness of the fifth lens is 2.27–2.383 mm.

[0023] The center thickness of the sixth lens is 0.93–0.977 mm;

[0024] The air gap between the first lens and the second lens is 0.738–0.775 mm.

[0025] The air gap between the second and third lenses is 0.076–0.079 mm.

[0026] The air gap between the third lens and the aperture stop is 0.066–0.069 mm.

[0027] The air gap between the aperture stop and the fourth lens is 0.049–0.0515 mm.

[0028] The air gap between the fourth and fifth lenses is 0.09796–0.103 mm.

[0029] The air gap between the fifth and sixth lenses is 0.304–0.319 mm.

[0030] The wide-angle lens of this application, through specially designed lens shape, optical power, radius of curvature, center thickness, air gap, and other parameters, and by combining three aspherical lenses with three other spherical lenses, has the advantages of good sharpness, low distortion, and small size. This wide-angle lens provides clear imaging in the 0.435 to 0.7 μm wavelength range, with a full-field MTF of 145 lp / mm > 0.1, while effectively correcting aberrations and controlling distortion, and meeting the following parameters:

[0031] Focal length: 2.5034-2.62857mm (at an object distance of 39.2 to 154.35mm), F number: 4.04, total optical length: 14.2521-15.1316mm (i.e., total length ≤ 15.2mm), FOV: 109.906-110.92°, image height: 3.43-3.6075mm, distortion < 5.714%, aperture ≤ 7mm.

[0032] Each aspherical surface conforms to the following odd-order aspherical surface formula:

[0033]

[0034] In the formula, r is the aperture perpendicular to the optical axis, z is the distance vector from the vertex of the aspherical surface at a height of r along the optical axis, c represents the vertex curvature of the surface (i.e., the reciprocal of the radius of curvature), k is the conic coefficient, β is the higher-order aspherical coefficient, the value of which is taken from the aspherical coefficient table, i is the order of the aspherical surface, βi is the coefficient of each higher-order term, and i is the higher power of the aspherical surface.

[0035] The first lens is made of plastic: 1.534≤n≤1.536, 55.7≤V d ≤56.1;

[0036] The second lens is made of glass: 1.92 ≤ n ≤ 1.946, 17.9 ≤ V d ≤20.9;

[0037] The third lens is made of glass: 2.00 ≤ n ≤ 2.104, 17.0 ≤ V d ≤26.9;

[0038] The fourth lens is made of glass: 1.57 ≤ n ≤ 1.593, 40.9 ≤ V d ≤68.3;

[0039] The fifth lens is made of plastic: 1.534≤n≤1.536, 55.7≤V d ≤56.1;

[0040] The sixth lens is made of plastic: 1.636≤n≤1.651, 21.5≤V d ≤24;

[0041] Where n is the refractive index and Vd is the Abbe coefficient.

[0042] The three aspherical lens elements of the wide-angle lens in this application are all made of plastic, which reduces the number of glass lenses in the lens and thus greatly reduces the cost.

[0043] The first lens has a half-diameter of 3.33–3.50 mm on its first surface and a half-diameter of 1.55–1.63 mm on its second surface.

[0044] The semi-diameter of the first surface of the second lens is 1.50–1.57 mm, and the semi-diameter of the second surface is 0.91–0.95 mm.

[0045] The third lens has a half-diameter of 0.81–0.86 mm on its first surface and a half-diameter of 0.51–0.54 mm on its second surface.

[0046] The semi-diameter of the aperture is 0.47–0.49 mm.

[0047] The semi-diameter of the first surface of the fourth lens is 0.62–0.65 mm, and the semi-diameter of the second surface is 1.54–1.61 mm.

[0048] The half-diameter of the first surface of the fifth lens is 1.76–1.84 mm, and the half-diameter of the second surface is 2.19–2.30 mm.

[0049] The semi-diameter of the first surface of the sixth lens is 2.21–2.32 mm, and the semi-diameter of the second surface is 2.60–2.73 mm.

[0050] The optimized semi-diameter parameters of each lens element result in a lower overall cost and smaller size for the wide-angle lens.

[0051] The wide-angle lens is located in front of the detector, and a protective glass, which is a planar lens, is provided between the detector and the wide-angle lens.

[0052] The air gap between the sixth lens and the protective glass is 0.316–0.332 mm; the air gap between the protective glass and the detector is 2.929–3.076 mm.

[0053] The thickness of the protective glass is 0.49 to 0.5145 mm.

[0054] The optimized protective glass design makes the detector less susceptible to scratches.

[0055] The protective glass is flat glass: n = 1.52, V d =64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0056] The selected protective glass is more durable and can further enhance the overall performance of wide-angle lenses.

[0057] The semi-diameter of the first surface of the protective glass is 2.85–2.99 mm, and the semi-diameter of the second surface is 2.91–3.05 mm.

[0058] Preferred protective glass is cheaper and smaller in size.

[0059] Compared with the prior art, this invention application has the following advantages:

[0060] 1) The wide-angle lens of this application has the advantages of good sharpness, low distortion and small size by specially designing parameters such as lens shape, optical power, radius of curvature, center thickness and air gap, and by the cooperation of three aspherical lenses and three spherical lenses.

[0061] 2) The three aspherical lens elements of the wide-angle lens in this application are all made of plastic material, which reduces the number of glass lenses in the lens as a whole, thereby greatly reducing the cost;

[0062] 3) Optimized semi-diameter parameters for each lens element result in lower overall cost and smaller size for the wide-angle lens;

[0063] 4) The preferred protective glass design makes the detector less susceptible to scratches. Attached Figure Description

[0064] Figure 1 This is an optical system diagram of the wide-angle lens described in this invention;

[0065] Figure 2 This is the MTF diagram of embodiment 1 of the wide-angle lens described in this invention;

[0066] Figure 3 This is a dot diagram of embodiment 1 of the wide-angle lens described in this invention;

[0067] Figure 4 This is the field curvature / distortion diagram of the wide-angle lens embodiment 1 described in this invention;

[0068] Figure 5 This is the illumination diagram of embodiment 1 of the wide-angle lens described in this invention;

[0069] Figure 6 This is the MTF diagram of embodiment 2 of the wide-angle lens described in this invention;

[0070] Figure 7 This is a dot diagram of embodiment 2 of the wide-angle lens described in this invention;

[0071] Figure 8 This is the field curvature / distortion diagram of the wide-angle lens embodiment 2 described in this invention;

[0072] Figure 9 This is the illumination diagram of embodiment 2 of the wide-angle lens described in this invention;

[0073] Figure 10 This is the MTF diagram of embodiment 3 of the wide-angle lens described in this invention;

[0074] Figure 11 This is a dot diagram of embodiment 3 of the wide-angle lens described in this invention;

[0075] Figure 12 This is the field curvature / distortion diagram of the wide-angle lens embodiment 3 described in this invention;

[0076] Figure 13 This is the illumination diagram of embodiment 3 of the wide-angle lens described in this invention.

[0077] Label Explanation:

[0078] 1. First lens, 2. Second lens, 3. Third lens, 4. Fourth lens, 5. Fifth lens, 6. Sixth lens, 7. Protective glass, 8. Aperture, 9. Detector. Detailed Implementation

[0079] The following is in conjunction with the instruction manual appendix. Figure 1-13 The technical solution of the present invention will be described in detail below.

[0080] Example 1

[0081] like Figure 1-5 As shown, the wide-angle lens of the present invention is composed of a first lens 1, a second lens 2, a third lens 3, an aperture 8, a fourth lens 4, a fifth lens 5, and a sixth lens 6 arranged sequentially from the object side to the image side; wherein, the first and second surfaces of the first lens 1, the fifth lens 5, and the sixth lens 6 are all odd-order aspherical surfaces, and all surfaces of the other lenses are spherical surfaces.

[0082] Each aspherical surface conforms to the following odd-order aspherical surface formula:

[0083]

[0084] In the formula, r is the aperture perpendicular to the optical axis, z is the distance vector from the vertex of the aspherical surface at a height of r along the optical axis, c represents the vertex curvature of the surface (i.e., the reciprocal of the radius of curvature), k is the conic coefficient, β is the higher-order aspherical coefficient (its value is taken from the aspherical coefficient table), i is the order of the aspherical surface, βi is the coefficient of each higher-order term, and i is the higher power of the aspherical surface. The aspherical coefficients are as follows (the coefficients of odd-order terms are 0):

[0085] Table 1 Aspherical coefficients

[0086]

[0087]

[0088] The first lens 1 is a negative power lens, with both its first and second surfaces being concave.

[0089] The second lens 2 is a positive power lens, with both its first and second surfaces being convex.

[0090] The third lens 3 is a negative power lens, with both its first and second surfaces being concave.

[0091] The fourth lens 4 is a positive power lens, with both its first and second surfaces being convex.

[0092] The fifth lens, 5, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0093] The sixth lens 6 is a negative power lens, with a concave first surface and a convex second surface;

[0094] The first lens 1 is made of plastic: n = 1.535, V d =55.7;

[0095] The second lens 2 is made of glass: n = 1.946, V d =17.9;

[0096] The third lens 3 is made of glass: n = 2.104, V d =17.0;

[0097] The fourth lens, 4, is made of glass: n = 1.593, V d =68.3;

[0098] The fifth lens 5 is made of plastic: n = 1.535, V d =55.7;

[0099] The sixth lens, 6, is made of plastic: n = 1.64, V d =23.5;

[0100] Where n is the refractive index and Vd is the Abbe coefficient.

[0101] The wide-angle lens is located in front of the detector 9, and a protective glass 7 is provided between the detector 9 and the wide-angle lens. The protective glass 7 is a planar lens.

[0102] Protective glass 7 is flat glass: n = 1.52, V d =64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0103] The optical structural parameters of the wide-angle lens in Example 1 are as follows:

[0104] Table 2 Optical structure parameters of the wide-angle lens in Example 1

[0105]

[0106]

[0107] The wide-angle lens described in Example 1 provides clear imaging in the 0.435 to 0.7 μm wavelength range, with a full-field MTF of 145 lp / mm > 0.1, and meets the following parameters: focal length: 2.55449 mm (object distance 40-150 mm), F-number: 4.04, total optical length: 14.5429-14.7051 mm, FOV: 109.906-110.92°, image height: 3.5 mm, and distortion < 5.714%.

[0108] Example 2

[0109] like Figure 1 , 6 As shown in Figure 9, the wide-angle lens of the present invention is composed of a first lens 1, a second lens 2, a third lens 3, an aperture 8, a fourth lens 4, a fifth lens 5, and a sixth lens 6 arranged sequentially from the object side to the image side; wherein, the first and second surfaces of the first lens 1, the fifth lens 5, and the sixth lens 6 are all odd-order aspherical surfaces, and all surfaces of the other lenses are spherical surfaces.

[0110] Each aspherical surface conforms to the following odd-order aspherical surface formula:

[0111]

[0112] In the formula, r is the aperture perpendicular to the optical axis, z is the distance sag from the vertex of the aspherical surface at a height of r along the optical axis, c represents the vertex curvature of the surface (i.e., the reciprocal of the radius of curvature), k is the conic coefficient, β is the higher-order aspherical coefficient (its value is taken from the aspherical coefficient table), i is the order of the aspherical surface, and β... i These are the coefficients of the higher-order terms, where i represents the higher powers of the aspheric surface. The aspheric coefficients are as follows (the coefficients of odd-order terms are 0):

[0113] Table 3 Aspherical Coefficients

[0114]

[0115] The first lens 1 is a negative power lens, with both its first and second surfaces being concave.

[0116] The second lens 2 is a positive power lens, with both its first and second surfaces being convex.

[0117] The third lens 3 is a negative power lens, with both its first and second surfaces being concave.

[0118] The fourth lens 4 is a positive power lens, with both its first and second surfaces being convex.

[0119] The fifth lens, 5, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0120] The sixth lens 6 is a negative power lens, with a concave first surface and a convex second surface;

[0121] The first lens 1 is made of plastic: n = 1.536, V d =56.0;

[0122] The second lens 2 is made of glass: n = 1.92, V d =20.9;

[0123] The third lens 3 is made of glass: n = 2.00, V d =19.3;

[0124] The fourth lens 4 is made of glass: n = 1.57, V d =71.3;

[0125] The fifth lens, 5, is made of plastic: n = 1.536, V d =56.0;

[0126] The sixth lens, 6, is made of plastic: n = 1.636, V d =24.0;

[0127] Where n is the refractive index and Vd is the Abbe coefficient.

[0128] The wide-angle lens is located in front of the detector 9, and a protective glass 7 is provided between the detector 9 and the wide-angle lens. The protective glass 7 is a planar lens.

[0129] Protective glass 7 is flat glass: n = 1.52, V d =64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0130] The optical structural parameters of the wide-angle lens in this embodiment 2 are as follows:

[0131] Table 4 Optical structural parameters of the wide-angle lens in Example 2

[0132]

[0133] The wide-angle lens described in Example 2 provides clear imaging in the 0.435 to 0.7 μm wavelength range, with a full-field MTF of 145 lp / mm > 0.1 and meeting the following parameters: focal length: 2.5034 mm (object distance 39.2-147 mm), F-number: 4.04, total optical length: 14.2521-14.411 mm, FOV: 109.906-110.92°, image height: 3.43 mm, and distortion < 5.714%.

[0134] Example 3

[0135] like Figure 1 , 10 As shown in Figure 13, the wide-angle lens of the present invention is composed of a first lens 1, a second lens 2, a third lens 3, an aperture 8, a fourth lens 4, a fifth lens 5, and a sixth lens 6 arranged sequentially from the object side to the image side; wherein, the first and second surfaces of the first lens 1, the fifth lens 5, and the sixth lens 6 are all odd-order aspherical surfaces, and all surfaces of the other lenses are spherical surfaces.

[0136] Each aspherical surface conforms to the following odd-order aspherical surface formula:

[0137]

[0138] In the formula, r is the aperture perpendicular to the optical axis, z is the distance sag from the vertex of the aspherical surface at a height of r along the optical axis, c represents the vertex curvature of the surface (i.e., the reciprocal of the radius of curvature), k is the conic coefficient, β is the higher-order aspherical coefficient (its value is taken from the aspherical coefficient table), i is the order of the aspherical surface, and β... i are the coefficients of each higher-order term, and i is the higher power of the aspherical surface.

[0139] The aspherical coefficients are as follows (the coefficients of odd-power terms are 0):

[0140] Table 5 Aspherical Coefficients

[0141]

[0142] The first lens 1 is a negative power lens, with both its first and second surfaces being concave.

[0143] The second lens 2 is a positive power lens, with both its first and second surfaces being convex.

[0144] The third lens 3 is a negative power lens, with both its first and second surfaces being concave.

[0145] The fourth lens 4 is a positive power lens, with both its first and second surfaces being convex.

[0146] The fifth lens, 5, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0147] The sixth lens 6 is a negative power lens, with a concave first surface and a convex second surface;

[0148] The first lens 1 is made of plastic: n = 1.534, V d =56.1;

[0149] The second lens 2 is made of glass: n = 1.923, V d =18.9;

[0150] The third lens 3 is made of glass: n = 2.05, V d =26.9;

[0151] The fourth lens, 4, is made of glass: n = 1.581, V d =40.9;

[0152] The fifth lens 5 is made of plastic: n = 1.534, V d =56.1;

[0153] The sixth lens, 6, is made of plastic: n = 1.651, V d =21.5;

[0154] Where n is the refractive index and Vd is the Abbe coefficient.

[0155] The wide-angle lens is located in front of the detector 9, and a protective glass 7 is provided between the detector 9 and the wide-angle lens. The protective glass 7 is a planar lens.

[0156] Protective glass 7 is flat glass: n = 1.52, V d =64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0157] The optical structural parameters of the wide-angle lens in this embodiment 3 are as follows:

[0158] Table 6 Optical structural parameters of the wide-angle lens in Example 3

[0159]

[0160] The wide-angle lens described in Example 3 provides clear imaging in the 0.435 to 0.7 μm wavelength range, with a full-field MTF of 145 lp / mm > 0.1 and meeting the following parameters: focal length: 2.62857 mm (object distance 41.16-154.35 mm), F-number: 4.04, total optical length: 14.9647-15.1316 mm, FOV: 109.906-110.92°, image height: 3.6015 mm, and distortion < 5.714%.

[0161] The wide-angle lens described in this invention is not limited to the above embodiments. Any improvements or substitutions based on the principles of this invention should be within the protection scope of this invention.

Claims

1. A wide-angle lens, characterized in that: The system consists of a first lens (1), a second lens (2), a third lens (3), an aperture (8), a fourth lens (4), a fifth lens (5), and a sixth lens (6) arranged sequentially from the object side to the image side; wherein the first and second surfaces of the first lens (1), the fifth lens (5), and the sixth lens (6) are odd-order aspherical surfaces, and the surfaces of the other lenses are spherical surfaces. The first lens (1) is a negative power lens, with a first concave surface and a second concave surface. The second lens (2) is a positive power lens, with both its first and second surfaces being convex. The third lens (3) is a negative power lens, with its first surface being concave and its second surface being concave. The fourth lens (4) is a positive power lens, with a convex first surface and a convex second surface. The fifth lens (5) is a positive power lens, with a convex first surface and a convex second surface. The sixth lens (6) is a negative power lens, with a concave first surface and a convex second surface; The radius of curvature of the first surface of the first lens (1) is -7.461 to -7.834 mm, and the radius of curvature of the second surface is 1.767 to 1.855 mm. The radius of curvature of the first surface of the second lens (2) is 3.591 to 3.770 mm, and the radius of curvature of the second surface is -20.435 to -21.457 mm. The radius of curvature of the first surface of the third lens (3) is -7.133 to -7.490 mm, and the radius of curvature of the second surface is 7.784 to 8.173 mm. The radius of curvature of the first surface of the fourth lens (4) is 4.248 to 4.460 mm, and the radius of curvature of the second surface is -3.609 to -3.790 mm. The radius of curvature of the first surface of the fifth lens (5) is 13.151 to 13.808 mm, and the radius of curvature of the second surface is -1.267 to -1.330 mm. The radius of curvature of the first surface of the sixth lens (6) is -0.812 to -0.853 mm, and the radius of curvature of the second surface is -1.503 to -1.578 mm; The center thickness of the first lens (1) is 1.463–1.536 mm. The center thickness of the second lens (2) is 1.596–1.676 mm. The center thickness of the third lens (3) is 0.784–0.823 mm. The center thickness of the fourth lens (4) is 2.303–2.418 mm. The center thickness of the fifth lens (5) is 2.27–2.383 mm. The center thickness of the sixth lens (6) is 0.93–0.977 mm; The air gap between the first lens (1) and the second lens (2) is 0.738–0.775 mm. The air gap between the second lens (2) and the third lens (3) is 0.076–0.079 mm. The air gap between the third lens (3) and the aperture (8) is 0.066–0.069 mm. The air gap between the aperture stop (8) and the fourth lens (4) is 0.049–0.0515 mm. The air gap between the fourth lens (4) and the fifth lens (5) is 0.09796–0.103 mm. The air gap between the fifth lens (5) and the sixth lens (6) is 0.304 to 0.319 mm.

2. The wide-angle lens according to claim 1, characterized in that: The first lens (1) is made of plastic: 1.534≤n≤1.536, 55.7≤V d ≤56.1; The second lens (2) is made of glass: 1.92≤n≤1.946, 17.9≤V d ≤20.9; The third lens (3) is made of glass: 2.00≤n≤2.104, 17.0≤V d ≤26.9; The fourth lens (4) is made of glass: 1.57≤n≤1.593, 40.9≤V d ≤68.3; The fifth lens (5) is made of plastic: 1.534≤n≤1.536, 55.7≤V d ≤56.1; The sixth lens (6) is made of plastic: 1.636≤n≤1.651, 21.5≤V d ≤24; Where n is the refractive index and Vd is the Abbe coefficient.

3. The wide-angle lens according to claim 1, characterized in that: The first lens (1) has a half-diameter of 3.33–3.50 mm on its first surface and a half-diameter of 1.55–1.63 mm on its second surface. The second lens (2) has a half-diameter of 1.50–1.57 mm on its first surface and a half-diameter of 0.91–0.95 mm on its second surface. The third lens (3) has a half-diameter of 0.81–0.86 mm on its first surface and a half-diameter of 0.51–0.54 mm on its second surface. The semi-diameter of the aperture (8) is 0.47–0.49 mm. The fourth lens (4) has a half-diameter of 0.62–0.65 mm on its first surface and a half-diameter of 1.54–1.61 mm on its second surface. The fifth lens (5) has a half-diameter of 1.76–1.84 mm on its first surface and a half-diameter of 2.19–2.30 mm on its second surface. The sixth lens (6) has a half-diameter of 2.21 to 2.32 mm on the first surface and a half-diameter of 2.60 to 2.73 mm on the second surface.

4. The wide-angle lens according to claim 1, characterized in that: The wide-angle lens is located in front of the detector (9), and a protective glass (7) is provided between the detector (9) and the wide-angle lens. The protective glass (7) is a plane lens. The air gap between the sixth lens (6) and the protective glass (7) is 0.316 to 0.332 mm; the air gap between the protective glass (7) and the detector (9) is 2.929 to 3.076 mm. The thickness of the protective glass (7) is 0.49 to 0.5145 mm.

5. The wide-angle lens according to claim 1, characterized in that: The protective glass (7) is flat glass: n = 1.52, V d =64.2; where n is the refractive index and Vd is the Abbe coefficient.

6. The wide-angle lens according to claim 1, characterized in that: The protective glass (7) has a half-diameter of 2.85 to 2.99 mm on the first surface and a half-diameter of 2.91 to 3.05 mm on the second surface.

Images