A vehicle-mounted front-view camera

Abstract

The present invention provides a vehicle-mounted front view lens, which has good processability, high resolution, and small distortion, and can achieve clear imaging in the range of -40° to 125°. It includes 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 the object side to the image side along the optical axis; five spherical lenses and two aspherical lenses are provided among the seven lenses; it also includes a diaphragm.

Description

Technical Field

[0001] The present invention relates to the technical field of lens structures, and particularly to a vehicle front view lens. Background Art

[0002] With the development of vehicle technologies, in the applications of front view camera devices, adaptive cruise control systems, and driving recorders, the technical requirements for vehicle cameras are getting higher and higher. Among them, the front view vehicle lens is an important part of the advanced driver assistance system. The driver can discover obstacles in front of the vehicle through the front view vehicle lens to avoid the occurrence of driving accidents.

[0003] However, the images captured by traditional front view camera lenses have low resolution, a small depth of field, and cannot clearly distinguish details at a long distance, making it impossible for the driving assistance system to accurately judge the information of the vehicle in front at a long distance in real time and then give timely warnings or avoidances, thus there are driving risks. Summary of the Invention

[0004] In view of the above problems, the present invention provides a vehicle front view lens, which has good processability, high resolution, and small distortion, and can achieve clear imaging in the range of -40° to 125°.

[0005] A vehicle front view 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 arranged in sequence from the object side to the image side along the optical axis; among the seven lenses, there are five spherical lenses and two aspherical lenses;

[0006] It further includes a diaphragm.

[0007] It is further characterized in that:

[0008] At least one flat plate and an image plane IMA are arranged in sequence behind the image side of the seventh lens;

[0009] Preferably, the first lens and the seventh lens are glass aspherical lenses, and the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are spherical lenses;

[0010] The second lens and the third lens form a cemented lens or a separated lens;

[0011] The fourth lens and the fifth lens form a cemented lens or a separated lens;

[0012] The sixth lens and the seventh lens form a cemented lens or a separated lens;

[0013] The first lens has Nd1 > 1.8 and Vd1 > 40; the second lens has Nd2 > 1.8 and Vd2 < 25; the third lens has Nd3 > 1.7 and Vd3 > 50; the fourth lens has Nd4 < 1.6 and Vd4 > 65; the fifth lens has Nd5 < 1.75 and Vd5 < 35; the sixth lens has Nd6 > 1.9 and Vd6 < 30; the seventh lens has Nd7 > 1.7 and Vd7 < 50;

[0014] The on-vehicle front view lens meets the condition: BFL / TTL > 0.15; where BFL is the distance from the center of the image side surface of the last lens of the optical lens to the imaging surface of the optical lens on the optical axis, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the optical lens on the optical axis; BFL / TTL > 0.15 is beneficial to increasing the optical back focus of the lens and leaving sufficient space for the module;

[0015] The on-vehicle front view lens meets the condition: 0.25 ≤ FOV / h / D ≤ 0.35; where FOV is the maximum field of view angle of the optical lens, D is the maximum clear aperture of the object side surface of the first lens corresponding to the maximum field of view angle of the optical lens, and h is the image height corresponding to the maximum field of view angle of the optical lens; it is beneficial for the front-end lens to achieve a small aperture;

[0016] Among the maximum field of view angle FOV of the on-vehicle front view lens, the overall focal length value f of the optical lens, and the image height h corresponding to the maximum field of view angle of the optical lens, the following is satisfied: 56.5 ≤ (FOV × f) / h ≤ 56.8. Controlling these three indicators is beneficial to reducing lens distortion;

[0017] The on-vehicle front view lens meets the condition: TTL / f ≤ 2.25; where TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the optical lens on the optical axis, and f is the overall focal length of the lens. Preferably, TTL / f ≤ 2.0, which is more beneficial to lens miniaturization;

[0018] The on-vehicle front view lens meets the conditions: 4.7 ≤ f1 / f ≤ 6.7, 0.1 ≤ f3 / f ≤ 1.5, -0.8 ≤ f5 / f ≤ -0.1; where f1, f3, and f5 are the focal lengths of the first lens, the third lens, and the fifth lens in sequence. By reasonably matching the focal lengths of the lenses, it is beneficial to reduce the assembly sensitivity and control the drift of the back focus at high and low temperatures within a very small range to meet clear imaging.

[0019] After adopting the present invention, it uses a combination of seven lenses, including 5 glass spherical lenses and 2 glass aspherical lenses, with good processability, high resolution, and small distortion, and can achieve clear imaging in the range of -40° to 125°. Description of the Drawings

[0020] Figure 1 Combined lens structure diagram of the first embodiment of the present invention (the object side is at the leftmost position and the image side is at the rightmost position);

[0021] Figure 2 Combined lens structure diagram of the second embodiment of the present invention (the object side is at the leftmost position and the image side is at the rightmost position);

[0022] Figure 3 Combined lens structure diagram of the third embodiment of the present invention (the object side is at the leftmost position and the image side is at the rightmost position);

[0023] Figure 4 Combined lens structure diagram of the fourth embodiment of the present invention (the object side is at the leftmost position and the image side is at the rightmost position);

[0024] Figure 5 Combined lens structure diagram of the fifth embodiment of the present invention (the object side is at the leftmost position and the image side is at the rightmost position);

[0025] The names corresponding to the serial numbers in the figure are as follows:

[0026] First lens 1, second lens 2, third lens 3, fourth lens 4, fifth lens 5, sixth lens 6, seventh lens 7, diaphragm 8, flat plate 9, IMA 10. Detailed implementation mode

[0027] A vehicle front view lens, see Figures 1 - 5 : It includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, and a seventh lens 7 arranged in sequence from the object side to the image side along the optical axis; among the seven lenses, there are five spherical lenses and two aspherical lenses;

[0028] It also includes a diaphragm 8.

[0029] At least one flat plate 9 and an image plane IMA 10 are arranged in sequence behind the image side of the seventh lens 7.

[0030] During specific implementation, the second lens and the third lens are combined to form a cemented lens or a separated lens.

[0031] During specific implementation, the fourth lens and the fifth lens form a cemented lens or a separated lens.

[0032] During specific implementation, the sixth lens and the seventh lens are combined to form a cemented lens or a separated lens.

[0033] A lens formed by combining seven lenses satisfies the following parameters: the first lens has Nd1 > 1.8 and Vd1 > 40; the second lens has Nd2 > 1.8 and Vd2 < 25; the third lens has Nd3 > 1.7 and Vd3 > 50; the fourth lens has Nd4 < 1.6 and Vd4 > 65; the fifth lens has Nd5 < 1.75 and Vd5 < 35; the sixth lens has Nd6 > 1.9 and Vd6 < 30; the seventh lens has Nd7 > 1.7 and Vd7 < 50.

[0034] The vehicle front view lens satisfies the condition: BFL / TTL > 0.15; where BFL is the distance from the center of the image side of the last lens of the optical lens to the imaging plane of the optical lens on the optical axis, and TTL is the distance from the center of the object side of the first lens to the imaging plane of the optical lens on the optical axis; BFL / TTL > 0.15 is beneficial to increasing the optical back focal length of the lens and leaving sufficient space for the module;

[0035] The vehicle front view lens satisfies the condition: 0.25 ≤ FOV / h / D ≤ 0.35; where FOV is the maximum field of view angle of the optical lens, D is the maximum clear aperture of the object side of the first lens corresponding to the maximum field of view angle of the optical lens, and h is the image height corresponding to the maximum field of view angle of the optical lens; it is beneficial for the front-end lens to achieve a small aperture;

[0036] Between the maximum field of view angle FOV of the vehicle front view lens, the overall focal length value f of the optical lens, and the image height h corresponding to the maximum field of view angle of the optical lens, it satisfies: 56.5 ≤ (FOV × f) / h ≤ 56.8. Controlling these three indicators is beneficial to reducing lens distortion;

[0037] The vehicle front view lens satisfies the condition: TTL / f ≤ 2.25; where TTL is the distance from the center of the object side of the first lens to the imaging plane of the optical lens on the optical axis, and f is the overall focal length of the lens,

[0038] In specific implementation, TTL / f ≤ 2.0 is more beneficial for lens miniaturization;

[0039] The vehicle front view lens satisfies the conditions: 4.7 ≤ f1 / f ≤ 6.7, 0.1 ≤ f3 / f ≤ 1.5, -0.8 ≤ f5 / f ≤ -0.1; where f1, f3, and f5 are the focal lengths of the first lens, the third lens, and the fifth lens in sequence. By reasonably matching the focal lengths of the lenses, it is beneficial to reduce the assembly sensitivity and control the drift of the back focal length of the lens at high and low temperatures within a very small range to meet clear imaging.

[0040] Specific embodiment one, its structure is shown in Figure 1: It includes a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a flat plate, and an image plane IMA, which are arranged in the incident direction from left to right along the optical axis. The second lens and the third lens form a cemented lens, and the fifth lens and the sixth lens form a cemented lens. The optical parameters are shown in Table 1:

[0041] Table 1

[0042]

[0043]

[0044] When the radius of curvature of the surfaces of the diaphragm, the IR filter, and the protective glass in Table 1 is Infinity, it means that this surface is a plane.

[0045] In this embodiment, the aspheric surface equation is as follows:

[0046]

[0047] Among them, z is the sagitta, the distance from the vertex of the aspheric surface when the height of the aspheric surface along the optical axis is r. c is the paraxial curvature of the aspheric surface, c = 1 / R, R is the radius of curvature, c is the reciprocal of the radius of curvature, k is the conic coefficient, a1 is the second-order coefficient of the aspheric surface, a2 is the fourth-order coefficient of the aspheric surface, a3 is the sixth-order coefficient of the aspheric surface, a4 is the eighth-order coefficient of the aspheric surface, a5 is the tenth-order coefficient of the aspheric surface, a6 is the twelfth-order coefficient of the aspheric surface, a7 is the fourteenth-order coefficient of the aspheric surface, and a8 is the sixteenth-order coefficient of the aspheric surface.

[0048] The optical parameters of Specific Embodiment 1 are shown in Table 2:

[0049] Table 2

[0050]

[0051] Specific Embodiment 2, its structure is shown in Figure 2 : A first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a flat plate, and an image plane IMA. The third lens and the fourth lens form a cemented lens, and the sixth lens and the seventh lens form a cemented lens. The optical parameters are shown in Table 3:

[0052] Table 3

[0053]

[0054] The coefficients of each term of the aspheric surface equation in Specific Embodiment 2 are shown in Table 4:

[0055] Table 4

[0056]

[0057] Specific Embodiment Three, the structure of which is shown in Figure 3 : It includes a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a protective glass, and an image plane IMA arranged in sequence along the optical axis in the incident direction from left to right. The fourth lens and the fifth lens are combined to form a cemented lens. The optical parameters are shown in Table 5:

[0058] Table 5

[0059]

[0060] The coefficients of each term of the aspheric equation in Specific Embodiment Three are shown in Table 6:

[0061] Table 6

[0062]

[0063] Specific Embodiment Four, the structure of which is shown in Figure 4 : It includes a first lens, a diaphragm, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a protective glass, and an image plane IMA arranged in sequence along the optical axis in the incident direction from left to right. The fourth lens and the fifth lens are combined to form a cemented lens. The sixth lens and the seventh lens are combined to form a cemented lens. The optical parameters are shown in Table 7:

[0064] Table 7

[0065]

[0066] The coefficients of each term of the aspheric equation in Specific Embodiment Four are shown in Table 8:

[0067] Table 8

[0068]

[0069] Specific Embodiment Five, the structure of which is shown in Figure 5:It includes an aperture, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a first protective glass, a second protective glass, an image plane IMA, and a fourth lens. The fifth lens is combined to form a cemented lens. The first lens is a meniscus, which is conducive to collecting light and reducing distortion. Setting it as a non-curved glass surface will further reduce aberrations and improve imaging quality; the aperture is set between the first lens and the second lens, which is conducive to reducing the lens aperture; the second lens is a meniscus negative lens and bends toward the first lens, which is conducive to receiving the refracted light more smoothly, reducing aberrations, reducing lens sensitivity, and also helping to reduce the lens aperture; the third lens, the fourth lens, and the sixth lens are positive lenses, which are conducive to refracting light and reducing the length of the lens; the fourth lens and the fifth lens form a cemented lens to reduce or eliminate chromatic aberration and improve imaging quality. The cemented lens improves the lens transmittance and reduces the difficulty of assembly. The seventh lens is a negative lens, which is conducive to correcting field curvature. At the same time, it is a glass aspheric surface to improve imaging quality. The optical parameters are shown in Table 9:

[0070] Table 9

[0071]

[0072]

[0073] The coefficients of the equation of the aspheric surface in the second specific embodiment are shown in Table 10:

[0074] Table 10

[0075]

[0076] The parameter values ​​corresponding to the specific embodiments 1 to 5 are shown in Table 11

[0077] Table 11

[0078] Specific Embodiment 1 Specific Embodiment 2 Specific Embodiment 3 Specific Embodiment 4 Specific Embodiment 5 f 15.3 15.35 15.35 15.29 15.341 BFL 5.41 8.58 3.7 8.46 5.28 TTL 32.54 34.25 32.33 34.25 33.9 FOV 35.2 35.2 35.2 35.2 35.2 h 9.52 9.52 9.52 9.52 9.52 D 11.12 10.6 11 11 11.58

[0079] It uses 5 glass spherical lenses and 2 glass aspherical lenses, which is suitable for manufacturing 8M vehicle-mounted front-view lenses. It has good processability, high resolution, small distortion, and can achieve clear imaging in the range of -40° to 125°.

[0080] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims concerned.

[0081] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A vehicle-mounted front-view 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 arranged in sequence from the object side to the image side along the optical axis; among the seven lenses, there are five spherical lenses and two aspherical lenses. It further includes a diaphragm. At least one flat plate and an image plane IMA are arranged in sequence behind the image side of the seventh lens. The first lens and the seventh lens are glass aspherical lenses, and the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are spherical lenses. The second lens and the third lens are combined to form a cemented lens or a separated lens. The fourth lens and the fifth lens form a cemented lens or a separated lens. For the first lens, Nd1 > 1.8 and Vd1 > 40; for the second lens, Nd2 > 1.8 and Vd2 < 25; for the third lens, Nd3 > 1.7 and Vd3 > 50; for the fourth lens, Nd4 < 1.6 and Vd4 > 65; for the fifth lens, Nd5 < 1.75 and Vd5 < 35; for the sixth lens, Nd6 > 1.9 and Vd6 < 30; for the seventh lens, Nd7 > 1.7 and Vd7 < 50. BFL / TTL > 0.15; where BFL is the distance from the center of the image side surface of the last lens of the vehicle front view lens to the imaging surface of the vehicle front view lens on the optical axis, and TTL is the distance from the center of the object side surface of the first lens to the imaging surface of the vehicle front view lens on the optical axis. The maximum field of view angle FOV of the vehicle front view lens, the overall focal length value f of the vehicle front view lens, and the image height h corresponding to the maximum field of view angle of the vehicle front view lens satisfy: 56.5 ≤ (FOV × f) / h ≤ 56.

8.

2. The vehicle-mounted front-view lens according to claim 1, characterized in that, The vehicle front view lens satisfies the condition: TTL / f ≤ 2.25.

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