A small-sized, low-chromatic-aberration, large-image-surface, high-resolution automotive fisheye lens

Abstract

The present invention discloses a small-volume, low-chromatic-aberration, large-target-area, and high-resolution vehicle-mounted fisheye lens. The optical system comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture C, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, and an image plane IMG, which are sequentially arranged along an incident light path. The first lens L1 to the fifth lens L5 form a front lens group; the sixth lens L6 to the ninth lens L9 form a rear lens group; the sixth lens L6, the seventh lens L7, and the eighth lens L8 are cemented together to form a cemented lens group. The vehicle-mounted fisheye lens satisfies the following conditions: 12≤TTL / f≤12.5, |f u1 / f|≤2.5, 3.7≤|f u2 The vehicle-mounted fisheye lens of the present invention has the characteristics of low distortion, low chromatic aberration, large target area, high resolution and small size.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical lenses, and in particular relates to a vehicle-mounted fisheye lens with small volume, low chromatic aberration, large target surface and high resolution. Background Art

[0002] As an important component of intelligent vehicle systems, the vehicle-mounted fisheye lens is an element for obtaining surrounding environment information and identifying objects.

[0003] According to the particularity of its application environment, some performance of automotive fisheye lenses needs to be different from that of ordinary lenses, such as small size, low chromatic aberration, high relative illumination, large target area, and high resolution.

[0004] The performance of existing fisheye lenses on the market has certain shortcomings. The market needs a fisheye lens with small size, low chromatic aberration, high relative illumination, large target area and high resolution.

[0005] Therefore, it is necessary to invent a monitoring lens that meets the above requirements. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a vehicle-mounted fisheye lens with small size, low chromatic aberration, large target surface and high resolution.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens, wherein the optical system of the automotive fisheye lens comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture C, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, and an image plane IMG, which are sequentially arranged along an incident light path.

[0008] The first lens L1 is a negative meniscus lens with its convex surface facing the object;

[0009] The second lens L2 is a negative meniscus lens with its convex surface facing the object;

[0010] The third lens L3 is a biconcave negative lens or a meniscus negative lens with its concave surface facing the object;

[0011] The fourth lens L4 is a positive meniscus lens with its convex surface facing the image side;

[0012] The fifth lens L5 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the object.

[0013] The sixth lens L6 is a biconvex positive lens;

[0014] The seventh lens L7 is a biconcave negative lens;

[0015] The eighth lens L8 is a biconvex positive lens;

[0016] The ninth lens L9 is a biconvex positive lens;

[0017] The first lens L1 to the fifth lens L5 form a front lens group; the sixth lens L6 to the ninth lens L9 form a rear lens group.

[0018] The sixth lens L6, the seventh lens L7 and the eighth lens L8 are cemented together to form a cemented lens assembly;

[0019] The vehicle-mounted fisheye lens satisfies the following condition: 12≤TTL / f≤12.5, |f u1 / f|≤2.5, 3.7≤|f u2 / f|≤3.8, where f u1 Indicates the effective focal length of the front lens group; f u2 It represents the effective focal length of the rear lens group; f represents the effective focal length of the car-mounted fisheye lens; TTL represents the total optical length of the car-mounted fisheye lens.

[0020] As a specific implementation, the vehicle-mounted fisheye lens also satisfies the following conditional formula: 58≤(FOV×f) / IH≤59, where FOV represents the maximum field of view angle of the vehicle-mounted fisheye lens; IH represents the maximum image plane height of the vehicle-mounted fisheye lens; and f represents the effective focal length of the vehicle-mounted fisheye lens.

[0021] As a specific implementation, the vehicle-mounted fisheye lens also satisfies the following condition: 0.6≤SD max / TTL≤0.7, where SD max It indicates the clear aperture of the largest lens in the car-mounted fisheye lens; TTL indicates the total optical length of the car-mounted fisheye lens.

[0022] As a specific implementation, the vehicle-mounted fisheye lens also satisfies the following condition: 0.3≤FOV / (D×TTL) ≤0.33, where FOV represents the maximum field of view of the vehicle-mounted fisheye lens; TTL represents the total optical length of the vehicle-mounted fisheye lens; and D represents the aperture size of the vehicle-mounted fisheye lens head.

[0023] As a specific implementation, the vehicle-mounted fisheye lens also satisfies the following condition: 1.9≤(f u1 +f u2 ) / IH≤2.1, where f u1 Indicates the effective focal length of the front lens group; f u2 Indicates the effective focal length of the rear lens group; IH indicates the maximum image height of the car fisheye lens.

[0024] As a specific implementation, the ninth lens L9 satisfies the following conditions: N d9 ≤1.9;V d9 ≥44, where N d9V represents the refractive index of the ninth lens L9; d9 It represents the Abbe number of the ninth lens L9.

[0025] As a specific embodiment, when the first lens L1 is a negative meniscus lens with its convex surface facing the object side; the second lens L2 is a negative meniscus lens with its convex surface facing the object side; the third lens L3 is a negative meniscus lens with its concave surface facing the object side; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image side; the fifth lens L5 is a positive meniscus lens with its convex surface facing the object side; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 2.2630 The air distance between the second lens L2 and the third lens L3 is 5.3200 mm; the air distance between the third lens L3 and the fourth lens L4 is 0.5805 mm; the air distance between the fourth lens L4 and the fifth lens L5 is 0.4178 mm; the air distance between the fifth lens L5 and the aperture C is 1.9782 mm; the air distance between the aperture C and the sixth lens L6 is 0.0979 mm; the air distance between the eighth lens L8 and the ninth lens L9 is 0.1036 mm; and the air distance between the ninth lens L9 and the image plane IMG is 5.0499 mm.

[0026] As a specific embodiment, when the first lens L1 is a negative meniscus lens with its convex surface facing the object side; the second lens L2 is a negative meniscus lens with its convex surface facing the object side; the third lens L3 is a biconcave negative lens; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image side; the fifth lens L5 is a positive meniscus lens with its convex surface facing the object side; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 2.2047 mm; The air distance from the second lens L2 to the third lens L3 is 4.7445mm; the air distance from the third lens L3 to the fourth lens L4 is 0.6140mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.3385mm; the air distance from the fifth lens L5 to the aperture C is 1.6500mm; the air distance from the aperture C to the sixth lens L6 is 0.0128mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.1050mm; and the air distance from the ninth lens L9 to the image plane IMG is 5.0088mm.

[0027] As a specific embodiment, when the first lens L1 is a negative meniscus lens with its convex surface facing the object side; the second lens L2 is a negative meniscus lens with its convex surface facing the object side; the third lens L3 is a negative meniscus lens with its concave surface facing the object side; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image side; the fifth lens L5 is a biconvex positive lens; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 2.4212 mm; The air distance from the second lens L2 to the third lens L3 is 4.7996mm; the air distance from the third lens L3 to the fourth lens L4 is 0.5065mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.1188mm; the air distance from the fifth lens L5 to the aperture C is 1.7102mm; the air distance from the aperture C to the sixth lens L6 is 0.1105mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.1256mm; and the air distance from the ninth lens L9 to the image plane IMG is 5.1326mm.

[0028] Compared with the existing technology, the present invention provides a small-volume, low-chromatic-aberration, large-target-area, high-resolution vehicle-mounted fisheye lens, which has the following beneficial effects:

[0029] 1) The present invention achieves the goal of low chromatic aberration by rationally controlling the optical power of the glued optical system lenses;

[0030] 2) The present invention achieves the high resolution requirement of the optical system by rationally allocating the positions of lenses with different optical powers;

[0031] 3) Achieving high system resolution by properly allocating the proportion of front and rear lens power to the overall lens power and properly controlling the ratio of optical power to total length of the optical system.

[0032] 4) By properly controlling the optical focal length, TTL is set to ≤ 30.2mm to meet the miniaturization requirements;

[0033] 5) The need for a large target surface is achieved by rationally allocating the relationship between the front and rear group optical powers and the maximum image plane height of the entire lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the optical path diagram of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 1;

[0035] Figure 2 This is the MTF curve of the visible light band of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 1;

[0036] Figure 3This is a relative illumination curve of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 1;

[0037] Figure 4 A vertical axis chromatic aberration curve of the visible light band of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 1;

[0038] Figure 5 This is the optical path diagram of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 2;

[0039] Figure 6 This is the MTF curve of the visible light band of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 2;

[0040] Figure 7 This is a relative illumination curve of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 2;

[0041] Figure 8 A vertical axis chromatic aberration curve of the visible light band of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 2;

[0042] Figure 9 This is the optical path diagram of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 3;

[0043] Figure 10 This is the MTF curve of the visible light band of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 3;

[0044] Figure 11 This is a relative illumination curve of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 3;

[0045] Figure 12 This is a vertical axis chromatic aberration curve of the visible light band of the small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens in Example 3. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] Disclosed is a small, low-chromatic-aberration, large-target-area, high-resolution vehicle-mounted fisheye lens. The optical system of the vehicle-mounted fisheye lens comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture C, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, and an image plane IMG, which are sequentially arranged along an incident light path. The first lens L1 is a negative meniscus lens with a convex surface facing the object; the second lens L2 is a negative meniscus lens with a convex surface facing the object; the third lens L3 is a biconcave negative lens or a negative meniscus lens with a concave surface facing the object; the fourth lens L4 is a positive meniscus lens with a convex surface facing the image; the fifth lens L5 is a biconvex positive lens or a positive meniscus lens with a convex surface facing the object; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens.

[0048] Among them, the first lens L1 to the fifth lens L5 form a front lens group; the sixth lens L6 to the ninth lens L9 form a rear lens group; the sixth lens L6, the seventh lens L7 and the eighth lens L8 are cemented together to form a cemented lens group.

[0049] The first lens L1 is a negative meniscus lens with a convex surface facing the object side, which focuses the light entering the lens, thereby facilitating the acquisition of more light.

[0050] The second lens L2 is a negative meniscus lens with its convex surface facing the object, which forms a double meniscus structure with the first lens L1, which can effectively reduce spherical aberration and improve imaging quality.

[0051] The third lens L3 can diverge the light transmitted by the second lens L2.

[0052] The fourth lens L4 can collect the light diverged by the third lens L3, correct it, and smoothly transmit it to the subsequent optical system.

[0053] The fifth lens L5 can collect and compress the light corrected by the fourth lens L4, which is beneficial to reducing the size of the lens.

[0054] The aperture C is placed between the fifth lens L5 and the sixth lens L6 to control the imaging quality and the performance of the optical system by limiting the propagation range and direction of the light beam.

[0055] The sixth lens L6, the seventh lens L7 and the eighth lens L8 form a cemented member, which corrects the light collected by the fifth lens L5, balances the distortion produced by the lens, and improves the imaging quality of the lens.

[0056] At the same time, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are made of glass lenses to further enhance the stability of the lens group.

[0057] The ninth lens element, L9, uses an aspherical lens to focus the light corrected by the triplet lens and perform final aberration correction, reducing the size of the lens and improving its imaging performance.

[0058] The lenses in the following embodiments are all made of glass with a normal refractive index.

[0059] Example 1

[0060] In the optical system of this example, the first lens L1 is a negative meniscus lens with its convex surface facing the object; the second lens L2 is a negative meniscus lens with its convex surface facing the object; the third lens L3 is a negative meniscus lens with its concave surface facing the object; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image; the fifth lens L5 is a positive meniscus lens with its convex surface facing the object; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens. The sixth lens L6, the seventh lens L7, and the eighth lens L8 form a cemented lens group. The optical path diagram of the vehicle-mounted fisheye lens is shown in FIG. Figure 1 shown.

[0061] See Table 1, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0062] Table 1

[0063]

[0064] Infinity means infinity.

[0065] In this example, the air distance between the first lens L1 and the second lens L2 is 2.2630 mm; the air distance between the second lens L2 and the third lens L3 is 5.3200 mm; the air distance between the third lens L3 and the fourth lens L4 is 0.5805 mm; the air distance between the fourth lens L4 and the fifth lens L5 is 0.4178 mm; the air distance between the fifth lens L5 and the aperture C is 1.9782 mm; the air distance between the aperture C and the sixth lens L6 is 0.0979 mm; the air distance between the eighth lens L8 and the ninth lens L9 is 0.1036 mm; and the air distance between the ninth lens L9 and the image plane IMG is 5.0499 mm.

[0066] The technical indicators achieved by the optical system in this example are as follows:

[0067] 1) Maximum field of view of the car fisheye lens: FOV = 180°;

[0068] 2) Effective focal length of the front lens group: f u1 =5.9353mm;

[0069] 3) Effective focal length of the rear lens group: f u2 =8.9983mm;

[0070] 4) Chief ray angle of the car fisheye lens: CRA = 13.5876°;

[0071] 5) Effective focal length of the on-board fisheye lens: f = 2.4279mm;

[0072] 6) Maximum image height of the vehicle-mounted fisheye lens: IH = 7.4244 mm;

[0073] 7) Total optical length of the vehicle-mounted fisheye lens: TTL = 30.1524mm;

[0074] 8) Aperture size of the car-mounted fisheye lens: D = 19.5533 mm;

[0075] 9) The clear aperture SD of the largest lens in the automotive fisheye lens max =19.5533mm;

[0076] 10) Abbe number of the ninth lens element L9: V d9 =44.26;

[0077] 11) Refractive index of the ninth lens element L9: N d9 =1.80.

[0078] Then we get: TTL / f=12.4191;(FOV×f) / IH=58.8629;|f u1 / f|=2.4446;|f u2 / f|=3.7062; SD max / TTL=0.6485;FOV / (D×TTL)=0.3053;(f u1 +f u2 ) / IH=2.0114.

[0079] Here, the high resolution requirement of the system is achieved by reasonably controlling the ratio of the optical power and total length of the optical system, that is, requiring 12≤TTL / f≤12.5.

[0080] By rationally combining lenses of different optical powers, that is, requiring 58<(FOV×f) / IH≤59, the propagation light in the optical system is continuously corrected, thereby achieving the high resolution requirement of the system.

[0081] By reasonably allocating the proportion of the front and rear group focal lengths to the focal length of the entire lens, that is, requiring |f u1 / f|≤2.5, 3.7≤|f u2 / f|≤3.8, meeting the system's high resolution requirements.

[0082] By properly controlling the optical focal length, TTL is made ≤ 30.2mm to meet the miniaturization requirements.

[0083] The final imaging effect of the lens in this example is achieved through Figure 2 The MTF graph shows that the MTF curves under each field of view all decrease smoothly and have good consistency. As can be seen from the graph, the MTF value is greater than 0.58 at the spatial frequency of 90pl / mm in the edge field of view, which means that the lens has good imaging effect and resolution in the entire field of view. Figure 3 It can be seen from the relative illumination curve that at the maximum field of view, the relative illumination value of the lens is greater than 0.8; Figure 4 This is a vertical axis chromatic aberration curve. It can be seen that the vertical axis chromatic aberration is less than 7μm.

[0084] Example 2

[0085] In the optical system of this example, the first lens L1 is a negative meniscus lens with its convex surface facing the object; the second lens L2 is a negative meniscus lens with its convex surface facing the object; the third lens L3 is a double-concave negative lens; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image; the fifth lens L5 is a positive meniscus lens with its convex surface facing the object; the sixth lens L6 is a double-convex positive lens; the seventh lens L7 is a double-concave negative lens; the eighth lens L8 is a double-convex positive lens; and the ninth lens L9 is a double-convex positive lens. The optical path diagram of this car fisheye lens is shown in Figure 5 shown.

[0086] See Table 2, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0087] Table 2

[0088]

[0089] Infinity means infinity.

[0090] In this example, the air distance between the first lens L1 and the second lens L2 is 2.2047 mm; the air distance between the second lens L2 and the third lens L3 is 4.7445 mm; the air distance between the third lens L3 and the fourth lens L4 is 0.6140 mm; the air distance between the fourth lens L4 and the fifth lens L5 is 0.3385 mm; the air distance between the fifth lens L5 and the aperture C is 1.6500 mm; the air distance between the aperture C and the sixth lens L6 is 0.0128 mm; the air distance between the eighth lens L8 and the ninth lens L9 is 0.1050 mm; and the air distance between the ninth lens L9 and the image plane IMG is 5.0088 mm.

[0091] The technical indicators achieved by the optical system in this example are as follows:

[0092] 1) Maximum field of view of the car fisheye lens: FOV = 180°;

[0093] 2) Effective focal length of the front lens group: f u1 =6.0092mm;

[0094] 3) Effective focal length of the rear lens group: f u2 =9.1135mm;

[0095] 4) Chief ray angle of the car fisheye lens: CRA = 15.5969°;

[0096] 5) Effective focal length of the on-board fisheye lens: f = 2.4192mm;

[0097] 6) Maximum image height of the vehicle-mounted fisheye lens: IH = 7.4244 mm;

[0098] 7) Total optical length of the vehicle-mounted fisheye lens: TTL = 30.1291 mm;

[0099] 8) Aperture size of the vehicle-mounted fisheye lens: D = 19.3111 mm;

[0100] 9) The clear aperture SD of the largest lens in the automotive fisheye lens max =19.3111mm;

[0101] 10) Abbe number of the ninth lens element L9: V d9 =44.26;

[0102] 11) Refractive index of the ninth lens element L9: N d9 =1.80.

[0103] Then we can get: TTL / f=12.4542;(FOV×f) / IH=58.6520;|f u1 / f|=2.4840;|f u2 / f|=3.7672; SD max / TTL=0.6409;FOV / (D×TTL)=0.3094;(f u1 +f u2 ) / IH=2.0369.

[0104] The final imaging effect of the lens in this example is achieved through Figure 6-8 To evaluate, from Figure 6 As can be seen from the figure, the MTF curves under each field of view all decrease smoothly and have good consistency. It can be seen from the figure that at the edge of the field of view at the spatial frequency of 00pl / mm, the MTF value is greater than 0.55, which means that the lens has good imaging effect and resolution in the entire field of view. Figure 7The relative illumination curve shows that at the maximum field of view, the relative illumination value of the lens is greater than 0.8; Figure 8 This is a vertical axis chromatic aberration curve. It can be seen that the vertical axis chromatic aberration is less than 7μm.

[0105] Example 3

[0106] In the optical system of this example, the first lens L1 is a negative meniscus lens with its convex surface facing the object; the second lens L2 is a negative meniscus lens with its convex surface facing the object; the third lens L3 is a negative meniscus lens with its concave surface facing the object; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image; the fifth lens L5 is a biconvex positive lens; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens. The optical path diagram of this car fisheye lens is shown in Figure 9 shown.

[0107] See Table 3, which lists the relevant parameters of each lens in this example, including the radius of curvature, thickness, refractive index of the material, and Abbe number:

[0108] Table 3

[0109]

[0110] Infinity means infinity.

[0111] In this example, the air distance between the first lens L1 and the second lens L2 is 2.4212 mm; the air distance between the second lens L2 and the third lens L3 is 4.7996 mm; the air distance between the third lens L3 and the fourth lens L4 is 0.5065 mm; the air distance between the fourth lens L4 and the fifth lens L5 is 0.1188 mm; the air distance between the fifth lens L5 and the aperture C is 1.7102 mm; the air distance between the aperture C and the sixth lens L6 is 0.1105 mm; the air distance between the eighth lens L8 and the ninth lens L9 is 0.1256 mm; and the air distance between the ninth lens L9 and the image plane IMG is 5.1326 mm.

[0112] The technical indicators achieved by the optical system in this example are as follows:

[0113] 1) Maximum field of view of the car fisheye lens: FOV = 180°;

[0114] 2) Effective focal length of the front lens group: f u1 =5.5567mm;

[0115] 3) Effective focal length of the rear lens group: f u2 =9.0691mm;

[0116] 4) Chief ray angle of the car fisheye lens: CRA = 13.7654°;

[0117] 5) Effective focal length of the on-board fisheye lens: f = 2.4151mm;

[0118] 6) Maximum image height of the vehicle-mounted fisheye lens: IH = 7.4244 mm;

[0119] 7) Total optical length of the vehicle-mounted fisheye lens: TTL = 29.9419 mm;

[0120] 8) Aperture size of the vehicle-mounted fisheye lens: D = 18.8286 mm;

[0121] 9) The clear aperture SD of the largest lens in the automotive fisheye lens max =18.8286mm;

[0122] 10) Abbe number of the ninth lens element L9: V d9 =44.26;

[0123] 11) Refractive index of the ninth lens element L9: N d9 =1.80.

[0124] Then we can get: TTL / f=12.3978;(FOV×f) / IH=58.5526;|f u1 / f|=2.3008;|f u2 / f|=3.7552; SD max / TTL=0.6288;FOV / (D×TTL)=0.3193;(f u1 +f u2 ) / IH=1.9700.

[0125] The final imaging effect of the lens in this example is achieved through Figure 10-12 To evaluate, from Figure 12 As can be seen from the figure, the MTF curves under each field of view all decrease smoothly and have good consistency. It can be seen from the figure that at the edge of the field of view at the spatial frequency of 00pl / mm, the MTF value is greater than 0.55, which means that the lens has good imaging effect and resolution in the entire field of view. Figure 11 It can be seen from the relative illumination curve that at the maximum field of view, the relative illumination value of the lens is greater than 0.8; Figure 12 2 is a vertical chromatic aberration curve of the lens of this embodiment. It can be seen that the vertical chromatic aberration is less than 7μm.

[0126] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens, characterized by: The optical system of the vehicle-mounted fisheye lens consists of a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, an aperture C, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and an image plane IMG, which are arranged in sequence along the incident light path. The first lens L1 is a negative meniscus lens with its convex surface facing the object; The second lens L2 is a negative meniscus lens with its convex surface facing the object; The third lens L3 is a biconcave negative lens or a meniscus negative lens with its concave surface facing the object; The fourth lens L4 is a positive meniscus lens with its convex surface facing the image side; The fifth lens L5 is a biconvex positive lens or a meniscus positive lens with the convex surface facing the object. The sixth lens L6 is a biconvex positive lens; The seventh lens L7 is a biconcave negative lens; The eighth lens L8 is a biconvex positive lens; The ninth lens L9 is a biconvex positive lens; The first lens L1 to the fifth lens L5 form a front lens group; the sixth lens L6 to the ninth lens L9 form a rear lens group. The sixth lens L6, the seventh lens L7 and the eighth lens L8 are cemented together to form a cemented lens assembly; The vehicle-mounted fisheye lens satisfies the following conditions: 12≤TTL / f≤12.5, 2.3008≤|f u1 / f|≤2.5, 3.7≤|f u2 / f|≤3.8, where f u1 Indicates the effective focal length of the front lens group; f u2 It represents the effective focal length of the rear lens group; f represents the effective focal length of the car-mounted fisheye lens; TTL represents the total optical length of the car-mounted fisheye lens.

2. The small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens according to claim 1, characterized in that: The vehicle-mounted fisheye lens also satisfies the following conditional formula: 58≤(FOV×f) / IH≤59, where FOV represents the maximum field of view angle of the vehicle-mounted fisheye lens; IH represents the maximum image plane height of the vehicle-mounted fisheye lens; and f represents the effective focal length of the vehicle-mounted fisheye lens.

3. The small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens according to claim 1, characterized in that: The vehicle-mounted fisheye lens also satisfies the following condition: 0.6≤SD max / TTL≤0.7, where SD max It indicates the clear aperture of the largest lens in the car-mounted fisheye lens; TTL indicates the total optical length of the car-mounted fisheye lens.

4. The small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens according to claim 1, characterized in that: The vehicle-mounted fisheye lens also satisfies the following conditional formula: 0.3≤FOV / (D×TTL)≤0.33, where FOV represents the maximum field of view of the vehicle-mounted fisheye lens; TTL represents the total optical length of the vehicle-mounted fisheye lens; and D represents the aperture size of the vehicle-mounted fisheye lens head.

5. The small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens according to claim 1, characterized in that: The vehicle-mounted fisheye lens also satisfies the following conditional formula: 1.9≤(f u1 +f u2 ) / IH≤2.1, where f u1 Indicates the effective focal length of the front lens group; f u2 Indicates the effective focal length of the rear lens group; IH indicates the maximum image height of the car fisheye lens.

6. The small-volume, low-chromatic-aberration, large-target-area, high-resolution vehicle-mounted fisheye lens according to claim 1, characterized in that: The ninth lens L9 satisfies the following conditions: N d9 ≤1.9;V d9 ≥44, where N d9 V represents the refractive index of the ninth lens L9; d9 It represents the Abbe number of the ninth lens L9.

7. The small-volume, low-chromatic-aberration, large-target-area, high-resolution vehicle-mounted fisheye lens according to claim 1, characterized in that: When the first lens L1 is a negative meniscus lens with its convex surface facing the object; the second lens L2 is a negative meniscus lens with its convex surface facing the object; the third lens L3 is a negative meniscus lens with its concave surface facing the object; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image; the fifth lens L5 is a positive meniscus lens with its convex surface facing the object; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 2.2630 mm; the second lens L4 is a positive meniscus lens with its convex surface facing the image; the fifth lens L5 is a positive meniscus lens with its convex surface facing the object; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 2.2630 mm; The air distance from the lens L2 to the third lens L3 is 5.3200mm; the air distance from the third lens L3 to the fourth lens L4 is 0.5805mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.4178mm; the air distance from the fifth lens L5 to the aperture C is 1.9782mm; the air distance from the aperture C to the sixth lens L6 is 0.0979mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.1036mm; and the air distance from the ninth lens L9 to the image plane IMG is 5.0499mm.

8. The small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens according to claim 1, characterized in that: When the first lens L1 is a negative meniscus lens with its convex surface facing the object; the second lens L2 is a negative meniscus lens with its convex surface facing the object; the third lens L3 is a double concave negative lens; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image; the fifth lens L5 is a positive meniscus lens with its convex surface facing the object; the sixth lens L6 is a double convex positive lens; the seventh lens L7 is a double concave negative lens; the eighth lens L8 is a double convex positive lens; and the ninth lens L9 is a double convex positive lens, the air distance from the first lens L1 to the second lens L2 is 2.2047 mm; the air distance from the second lens L2 to The air distance of the third lens L3 is 4.7445mm; the air distance from the third lens L3 to the fourth lens L4 is 0.6140mm; the air distance from the fourth lens L4 to the fifth lens L5 is 0.3385mm; the air distance from the fifth lens L5 to the aperture C is 1.6500mm; the air distance from the aperture C to the sixth lens L6 is 0.0128mm; the air distance from the eighth lens L8 to the ninth lens L9 is 0.1050mm; and the air distance from the ninth lens L9 to the image plane IMG is 5.0088mm.

9. The small-volume, low-chromatic-aberration, large-target-area, high-resolution automotive fisheye lens according to claim 1, characterized in that: When the first lens L1 is a negative meniscus lens with its convex surface facing the object; the second lens L2 is a negative meniscus lens with its convex surface facing the object; the third lens L3 is a negative meniscus lens with its concave surface facing the object; the fourth lens L4 is a positive meniscus lens with its convex surface facing the image; the fifth lens L5 is a biconvex positive lens; the sixth lens L6 is a biconvex positive lens; the seventh lens L7 is a biconcave negative lens; the eighth lens L8 is a biconvex positive lens; and the ninth lens L9 is a biconvex positive lens, the air distance from the first lens L1 to the second lens L2 is 2.4212 mm; and the air distance from the second lens L2 to the third lens L3 is 4.7996 mm. The air distance between the third lens L3 and the fourth lens L4 is 0.5065mm; the air distance between the fourth lens L4 and the fifth lens L5 is 0.1188mm; the air distance between the fifth lens L5 and the aperture C is 1.7102mm; the air distance between the aperture C and the sixth lens L6 is 0.1105mm; the air distance between the eighth lens L8 and the ninth lens L9 is 0.1256mm; and the air distance between the ninth lens L9 and the image plane IMG is 5.1326mm.

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