Vehicle-mounted front-view lens

Abstract

The utility model discloses a vehicle front vision lens head relates to optical system technical field, wherein, vehicle front vision lens head includes the first lens group of negative optical power, the second lens group of positive optical power and the image surface that are arranged in order from object side to image side along the direction of optical axis, vehicle front vision lens head satisfies the following condition :-40F11 / FF-8, and 0F22 / FF2.0, the focal length of vehicle front vision lens head is F, the focal length of first lens group is F11, the focal length of second lens group is F12. Thus, with the diameter of image surface of vehicle front vision lens head can reach 9.5mm, and, with the resolving power of vehicle chamber lens reaches eight million pixels, to realize high resolution, high illumination and small distortion ability of vehicle front vision lens head.

Description

Technical Field

[0001] This utility model relates to the field of optical system technology, and in particular to a vehicle-mounted forward-looking lens. Background Technology

[0002] Currently, intelligent driving systems have become one of the core R&D directions for mainstream automakers. The forward-facing camera, as a crucial component of intelligent driving systems, is responsible for functions such as road condition recognition, lane departure warning, and collision warning. However, current mainstream forward-facing cameras suffer from problems such as low image resolution and low illumination, limiting their ability to detect distant, small targets and failing to meet the early warning requirements of Advanced Driver Assistance Systems (ADAS). Furthermore, in extreme conditions of hot or cold, excessive thermal defocusing of the lens can lead to blurred images, affecting the vehicle's normal operation. Utility Model Content

[0003] The main purpose of this invention is to propose a vehicle-mounted forward-viewing lens, which aims to improve the existing vehicle forward-viewing lenses that cannot meet the early warning requirements of advanced driver assistance systems (ADAS), and that in extreme conditions of hot or cold, excessive thermal defocusing of the lens can lead to blurred images, affecting the normal driving of the vehicle.

[0004] To achieve the above objectives, the present invention proposes a vehicle-mounted forward-looking lens, comprising a first lens group with negative optical power, a second lens group with positive optical power, and an image plane arranged sequentially from the object side to the image side along the optical axis. The vehicle-mounted forward-looking lens satisfies the following conditions: -40 < F11 / F < -8, and 0 < F22 / F < 2.0; The focal length of the vehicle-mounted forward-looking lens is F, the focal length of the first lens group is F11, and the focal length of the second lens group is F12.

[0005] In one embodiment, the first lens group includes a first lens with negative optical power. The first lens is configured as a glass spherical lens with a concave object side and a convex image side. The focal length of the first lens is F1, where -40 < F1 / F < -20.

[0006] In one embodiment, the refractive index of the first lens is Nd1, where Nd1 ≥ 1.5.

[0007] In one embodiment, the aperture of the first lens is D1, and the radius of curvature near the image side is r2, where -1.5 < D1 / r2 < -0.5.

[0008] In one embodiment, the second lens group includes a second lens with positive optical power, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power, arranged sequentially from the object side to the image side along the optical axis. The second lens is a glass aspherical lens, and the third, fourth, fifth, and sixth lenses are glass spherical lenses. The second lens group satisfies the following condition: 0<F2 / F<1.5; -2<F3 / F<0; 0<F4 / F<1.5; -5<F5 / F<-1; -2.5<F6 / F<-0.5; The second lens has a focal length of F2, the third lens has a focal length of F3, the fourth lens has a focal length of F4, the fifth lens has a focal length of F5, and the sixth lens has a focal length of F6.

[0009] In one embodiment, the object-side surface of the second lens is convex, and the image-side surface is also convex. The object-side surface of the third lens is flat, and the image-side surface is concave. The object-side surface of the fourth lens is convex, and the image-side surface is also convex. The object-side surface of the fifth lens is convex, and the image-side surface is concave. The object-side surface of the sixth lens is concave, and the image-side surface is convex.

[0010] In one embodiment, the refractive index of the second lens is Nd2, where 1.45 ≤ Nd2 ≤ 1.6; The refractive index of the third lens is Nd3, 1.6≤Nd3≤1.8; The refractive index of the fourth lens is Nd4, 1.6≤Nd4≤1.8; The refractive index of the fifth lens is Nd5, where 1.45 ≤ Nd5 ≤ 1.8; The refractive index of the sixth lens is Nd6, where 1.6 ≤ Nd6 ≤ 1.7.

[0011] In one embodiment, the radius of curvature of the second lens near the object side is r4, and the radius of curvature near the image side is r5, where -4≤r5 / r4≤-1.5; The radius of curvature of the third lens near the object side is r6, and the radius of curvature near the image side is r7, r7 / r6=0; The radius of curvature of the fourth lens near the object side is r8, and the radius of curvature near the image side is r9, where -3.0 ≤ r9 / r8 ≤ -1.0; The radius of curvature of the fifth lens near the object side is r10, and the radius of curvature near the image side is r11, where 0 ≤ r11 / r10 ≤ 1.5; The radius of curvature of the sixth lens near the object side is r12, and the radius of curvature near the image side is r13, where 1.5 ≤ r13 / r12 ≤ 3.5.

[0012] In one embodiment, the vehicle-mounted forward-looking lens further includes an anti-reflective coating, which is deposited on the object-side surface of the third lens to reduce reflected light on the object-side surface of the third lens.

[0013] In one embodiment, the vehicle-mounted forward-looking lens further includes an aperture stop and a protective glass arranged sequentially from the object side to the image side along the optical axis. The aperture stop is located between the first lens group and the second lens group, and the protective glass is located on the side of the second lens group closer to the image plane.

[0014] In the technical solution of this utility model, the light collected by the vehicle-mounted front-view lens is successively incident into the first lens group and the second lens group, and finally illuminates the image plane to form an image. At this time, by limiting the focal length of multiple lenses in the first lens group and the second lens group, -40 < F11 / F < -8, and 0 < F22 / F < 2.0, and the focal length of the vehicle-mounted front-view lens is F, the focal length of the first lens group is F11, and the focal length of the second lens group is F12, so that the diameter of the image plane of the vehicle-mounted front-view lens can reach 9.5mm, and the resolution of the vehicle-mounted cavity lens can reach eight million pixels, so as to achieve high resolution, high illumination and low distortion capability of the vehicle-mounted front-view lens. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of an embodiment of the vehicle-mounted forward-looking lens provided by this utility model; Figure 2 for Figure 1 MTF curve of a vehicle-mounted forward-looking camera; Figure 3 for Figure 1 Defocus curve of a vehicle-mounted front-view camera at an ambient temperature of 25℃; Figure 4 for Figure 1 Relative illumination diagram of the main wavelength of the forward-looking camera in a vehicle; Figure 5 for Figure 1Field curvature and distortion curves of a vehicle-mounted forward-looking camera in the visible light band; Figure 6 A schematic diagram of another embodiment of the vehicle-mounted forward-looking lens provided by this utility model; Figure 7 for Figure 6 MTF curve of a vehicle-mounted forward-looking camera; Figure 8 for Figure 6 Defocus curve of a vehicle-mounted front-view camera at an ambient temperature of 25℃; Figure 9 for Figure 6 Relative illumination diagram of the main wavelength of the forward-looking camera in a vehicle; Figure 10 for Figure 6 Field curvature and distortion curves of a vehicle-mounted forward-looking camera in the visible light band.

[0017] Explanation of icon numbers: 100. Vehicle-mounted front-view camera; 1. First lens group; 11. First lens; 2. Second lens group; 21. Second lens; 22. Third lens; 23. Fourth lens; 24. Fifth lens; 25. Sixth lens; 3. Image plane; 4. Aperture; 5. Protective glass.

[0018] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0020] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0022] This invention proposes a vehicle-mounted forward-viewing lens, aiming to improve the existing automotive forward-viewing lenses, which cannot meet the early warning requirements of advanced driver assistance systems (ADAS), and where excessive thermal defocusing of the lens under extreme hot or cold conditions can lead to blurred images and affect the normal driving of the vehicle.

[0023] Please see Figure 1 In one embodiment of this utility model, the vehicle-mounted front-view lens 100 includes a first lens group 1 with negative optical power, a second lens group 2 with positive optical power, and an image plane 3 arranged sequentially from the object side to the image side along the optical axis. The vehicle-mounted front-view lens 100 satisfies the following conditions: -40 < F11 / F < -8, and 0 < F22 / F < 2.0. The focal length of the vehicle-mounted front-view lens 100 is F, the focal length of the first lens group 1 is F11, and the focal length of the second lens group 2 is F12.

[0024] In the technical solution of this utility model, the light collected by the vehicle-mounted front-view lens 100 is successively incident into the first lens group 1 and the second lens group 2, and finally illuminates the image plane 3 for imaging. At this time, by limiting the focal length of multiple lenses in the first lens group 1 and the second lens group 2, -40 < F11 / F < -8, and 0 < F22 / F < 2.0, and the focal length of the vehicle-mounted front-view lens 100 is F, the focal length of the first lens group 1 is F11, and the focal length of the second lens group 2 is F12, so that the diameter of the image plane 3 of the vehicle-mounted front-view lens 100 can reach 9.5mm, and the resolution of the vehicle-mounted cavity lens can reach eight million pixels, so as to achieve high resolution, high illumination and low distortion capability of the vehicle-mounted front-view lens 100.

[0025] It should be noted that in this utility model, the optical power of the first lens group 1 is set to a negative value, which can further increase the amount of light incident on the vehicle front view lens 100, thereby improving the brightness of the vehicle front view lens 100; while the optical power of the second lens group 2 is set to a positive value, which can enable the second lens group 2 to focus the light, thereby enabling it to be successfully imaged on the image plane 3.

[0026] In one embodiment of this utility model, the first lens group 1 includes a first lens 11 with negative optical power. The first lens 11 is a glass spherical lens with a concave object side and a convex image side. The focal length of the first lens 11 is F1, where -40 < F1 / F < -20. By setting the material of the first lens 11 to be a glass lens, when light enters the vehicle-mounted front-view lens 100, the light first enters the first lens 11. Since the first lens 11 is a glass lens, its deformation due to heat is small. Therefore, the vehicle-mounted front-view lens 100 can have good thermal performance, reducing the impact of the heat of the incident light on the imaging of the vehicle-mounted front-view lens 100.

[0027] Meanwhile, by setting the first lens 11 as a spherical lens, the manufacturing difficulty of the first lens 11 can be reduced, thereby reducing the manufacturing cost of the vehicle-mounted forward-looking lens 100.

[0028] It is understood that this utility model does not limit the specific value of the ratio of the focal length F1 of the first lens 11 to the focal length F of the vehicle front-view lens 100. In this utility model, the ratio of the focal length of the first lens 11 to the focal length of the vehicle front-view lens 100 can be set to any value within its range, as long as the optimization of the imaging quality of the vehicle front-view lens 100 by the first lens 11 is guaranteed. In actual settings, it can be selected according to the requirements, and this utility model does not impose any restrictions on it.

[0029] In a further embodiment of this invention, the refractive index of the first lens 11 is Nd1, where Nd1 ≥ 1.5. This setting, by limiting the refractive index of the first lens 11, facilitates adjusting the exit direction of large-angle light rays, reducing the incident angle, and minimizing introduced higher-order aberrations.

[0030] Of course, this utility model does not limit the specific value of the refractive index of the first lens 11. In this utility model, the specific value of the refractive index of the first lens 11 can also be set to any value within its range to ensure the refraction effect of the first lens 11 on light. In actual setting, it can be selected according to the needs.

[0031] In a further embodiment of this invention, the aperture of the first lens 11 is D1, and the radius of curvature near the image side is r2, where -1.5 < D1 / r2 < -0.5. This effectively controls the risk of the first lens 11 being hemispherical, which is beneficial for its manufacturing process. Simultaneously, the first lens 11 has a certain degree of curvature, which can correct optical system aberrations to a certain extent.

[0032] Similarly, it is understood that in this invention, the ratio of the aperture of the first lens 11 to the radius of curvature near the image side can also be set to any value within its range. For example, in some embodiments of this invention, D1 / r2 = -1; in other embodiments of this invention, D1 / r2 = -0.8. Of course, the ratio of the aperture of the first lens 11 to its radius of curvature near the image side can also be set to other values. In actual settings, it can be selected according to the requirements, and this invention does not impose any restrictions on this.

[0033] In other embodiments of this utility model, the second lens group 2 includes a second lens 21 with positive optical power, a third lens 22 with negative optical power, a fourth lens 23 with positive optical power, a fifth lens 24 with negative optical power, and a sixth lens 25 with negative optical power, arranged sequentially from the object side to the image side along the optical axis. The second lens 21 is a glass aspherical lens, and the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25 are glass spherical lenses. The second lens group 2 satisfies the following conditions: 0 < F2 / F < 1.5; -2 < F3 / F < 0; 0 < F4 / F < 1.5; -5 < F5 / F < -1; -2.5 < F6 / F < -0.5. The focal length of the second lens 21 is F2, the focal length of the third lens 22 is F3, the focal length of the fourth lens 23 is F4, the focal length of the fifth lens 24 is F5, and the focal length of the sixth lens 25 is F6. In this invention, the second lens 21 is configured as an aspherical lens, which gives the second lens 21 better curvature radius characteristics and the advantages of improving distortion aberration, astigmatism, and phase aberration. By using an aspherical lens, aberrations that occur during imaging of the vehicle front-view lens 100 can be eliminated as much as possible, thereby improving edge image quality and improving the imaging quality of the vehicle front-view lens 100.

[0034] It is understood that this utility model does not limit the specific values ​​of the ratios of the focal lengths of the second lens 21, the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25 to the focal length of the vehicle-mounted front-view lens 100. In this utility model, the specific values ​​of the ratios of the focal lengths of the second lens 21, the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25 to the focal length of the vehicle-mounted front-view lens 100 can all be set to any value within the corresponding range. It is only necessary to ensure that the focal lengths of the five lenses are coordinated to guarantee the light processing quality of the second lens group 2. In actual settings, the selection can be made according to the requirements, and this utility model does not impose any restrictions on this.

[0035] In one specific embodiment of this utility model, the object-side surface of the second lens 21 is convex, the image-side surface of the third lens 22 is planar, and the image-side surface is concave; the object-side surface of the fourth lens 23 is convex, and the image-side surface is convex; the object-side surface of the fifth lens 24 is convex, and the image-side surface is concave; and the object-side surface of the sixth lens 25 is concave, and the image-side surface is convex.

[0036] It should be noted that making the object side of the third lens 22 a plane is beneficial for depositing an anti-reflection coating on the plane, thereby further improving the imaging quality by filtering out stray light from other wavelengths.

[0037] In a further embodiment of this utility model, the refractive index of the second lens 21 is Nd2, 1.45≤Nd2≤1.6; the refractive index of the third lens 22 is Nd3, 1.6≤Nd3≤1.8; the refractive index of the fourth lens 23 is Nd4, 1.6≤Nd4≤1.8; the refractive index of the fifth lens 24 is Nd5, 1.45≤Nd5≤1.8; and the refractive index of the sixth lens 25 is Nd6, 1.6≤Nd6≤1.7.

[0038] Similarly, it is understood that this utility model does not limit the specific values ​​of the refractive indices of the second lens 21, the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25. In this utility model, the refractive indices of the second lens 21, the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25 can all be set to any value within the corresponding range. It is only necessary to ensure that the coordination of the refractive indices of the five lenses guarantees the imaging quality of the vehicle-mounted forward-looking lens 100. In actual settings, they can also be selected according to requirements.

[0039] In a further embodiment of this utility model, the second lens 21 has a radius of curvature of r4 near the object side and a radius of curvature of r5 near the image side, with -4≤r5 / r4≤-1.5; the third lens 22 has a radius of curvature of r6 near the object side and a radius of curvature of r7 near the image side, with r7 / r6=0; the fourth lens 23 has a radius of curvature of r8 near the object side and a radius of curvature of r9 near the image side, with -3.0≤r9 / r8≤-1.0; the fifth lens 24 has a radius of curvature of r10 near the object side and a radius of curvature of r11 near the image side, with 0≤r11 / r10≤1.5; and the sixth lens 25 has a radius of curvature of r12 near the object side and a radius of curvature of r13 near the image side, with 1.5≤r13 / r12≤3.5.

[0040] It should be noted that limiting -4≤r5 / r4≤-1.5 can control distortion and, to a certain extent, correct the aberrations of the vehicle-mounted forward-viewing lens 100.

[0041] Of course, this method does not limit the specific value of the ratio of the radius of curvature away from the image side to the radius of curvature near the image side for each of the second lens 21, the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25. In actual settings, the specific ratios of the radius of curvature away from the image side and the radius of curvature near the image side for the second lens 21, the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25 can all be set to any value within the corresponding range. Similarly, it is only necessary to ensure that the specific values ​​of the five lenses are coordinated to guarantee the imaging quality of the vehicle-mounted forward-looking lens 100.

[0042] Furthermore, to further improve the imaging quality of the vehicle-mounted front-view lens 100, in one embodiment of this utility model, the vehicle-mounted front-view lens 100 also includes an anti-reflection coating. The anti-reflection coating is deposited on the object-side surface of the third lens 22 to reduce reflected light on the object-side surface of the third lens 22. Thus, by depositing the anti-reflection coating on the object-side surface of the third lens 22, the anti-reflection coating can reduce the reflected light generated when light shines on the object-side surface of the third lens 22, thereby reducing glare and ghosting caused by reflections between multiple lenses, further improving the imaging quality of the vehicle-mounted front-view lens 100. Simultaneously, the anti-reflection coating allows the vehicle-mounted front-view lens 100 to reduce the number of filters, thereby reducing the manufacturing cost and weight of the vehicle-mounted front-view lens 100.

[0043] It should also be noted that, in another embodiment of this utility model, the vehicle-mounted forward-viewing lens 100 further includes an aperture 4, which is disposed between the first lens group 1 and the second lens group 2. With this arrangement, the aperture 4 can effectively control the light transmission aperture, thereby reducing stray light interference and improving image quality.

[0044] In a further embodiment of this utility model, the vehicle-mounted forward-viewing lens 100 also includes a protective glass 5, which provides effective protection for the image surface 3.

[0045] This utility model provides an effective specific embodiment of the vehicle-mounted forward-looking lens 100. In this embodiment, the vehicle-mounted forward-looking lens 100 includes a first lens 11, an aperture 4, a second lens 21, a third lens 22, a fourth lens 23, a fifth lens 24, a sixth lens 25, a protective glass 5, and an image plane 3, arranged sequentially from the object side to the image side along the optical axis. The image side and the object side of the protective glass 5 are both planar. The first lens 11 has a negative optical power, and the object side S1 is concave while the image side S2 is convex. The second lens 21 has a positive optical power, and its object-side surface S4 is convex, and its image-side surface S5 is convex. The third lens 22 has a negative optical power, and its object-side surface S6 is flat, and its image-side surface S7 is concave. The fourth lens 23 has a positive optical power, and its object-side surface S8 is convex, and its image-side surface S9 is convex. The fifth lens 24 has a negative optical power, and its object-side surface S10 is convex, and its image-side surface S11 is concave. The sixth lens 25 has a negative optical power, and its object-side surface S12 is concave, and its image-side surface S13 is convex.

[0046] In this embodiment, the optical assembly of the vehicle-mounted forward-looking lens 100 is set to TTL, TTL=30.1mm, the aperture number is set to FNO, FNO=1.6, the first lens 11, the third lens 22 and the sixth lens 25 are set as high dispersion lenses with an Abbe number ≤50 dB, and the refractive index Nd of the first lens 11, the third lens 22, the fourth lens 23 and the sixth lens 25 is ≥1.6.

[0047] In this embodiment, the basic parameters of each lens of the vehicle-mounted forward-looking lens 100, including surface type, radius of curvature (mm), thickness (mm), material characteristics, and Conic value, are shown in Table 1: Table 1

[0048] As disclosed above, in this embodiment, the ratio of the focal length of the first lens 11 to the focal length of the vehicle-mounted front-view lens 100 is F1 / F = -26.928; the ratio of the focal length of the second lens 21 to the focal length of the vehicle-mounted front-view lens 100 is F2 / F = 0.970; the ratio of the focal length of the third lens 22 to the focal length of the vehicle-mounted front-view lens 100 is F3 / F = -0.871; the ratio of the focal length of the fourth lens 23 to the focal length of the vehicle-mounted front-view lens 100 is F4 / F = 0.727; the ratio of the focal length of the fifth lens 24 to the focal length of the vehicle-mounted front-view lens 100 is F5 / F = -3.133; and the ratio of the focal length of the sixth lens 25 to the focal length of the vehicle-mounted front-view lens 100 is F6 / F = -1.250.

[0049] In this embodiment, D1 / r2=-0.817; r5 / r4=-2.848; r7 / r6=0.000; r9 / r8=-1.718; r11 / r10=0.541; r13 / r12=2.206.

[0050] Furthermore, in this embodiment, the aspherical surface shape of the aspherical lens satisfies the following condition:

[0051] Where Z represents the distance of the surface from the vertex of the surface in the optical axis direction, parameter c is the curvature corresponding to the radius, y is the radial coordinate, and its unit is the same as the lens length unit, k is the conic quadratic coefficient; when the coefficient k is less than -1, the surface curve of the lens is a hyperbola, when the coefficient k is equal to -1, the surface curve of the lens is a parabola; when the coefficient k is between -1 and 0, the surface curve of the lens is an ellipse, when the coefficient k is equal to 0, the surface curve of the lens is a circle, when the coefficient k is greater than 0, the surface curve of the lens is an oval, and α1 to α8 represent the coefficients corresponding to each radial coordinate.

[0052] In this embodiment, the coefficients of the higher-order terms of each aspherical mirror are shown in Table 2 below: Table 2

[0053] It is understandable that number 4 is the object-side number of the second lens 21, and number 5 is the image-side number of the second lens 21.

[0054] This setup, by rationally allocating the lens power and adjusting the glass shape and material combination, effectively eliminates chromatic aberration and secondary spectrum, allowing spherical aberration, coma, astigmatism, etc. on each lens to compensate and cancel each other out, thereby achieving a clear imaging effect and realizing optimal correction of higher-order aberrations and chromatic aberration.

[0055] It should be noted that, Figure 2 This is the MTF curve of the vehicle-mounted forward-looking camera 100 described in this embodiment, derived from... Figure 2 It can be seen that the MTF value of the vehicle-mounted front-view lens 100 at the maximum image plane Φ9.3mm is above 0.3, indicating that the vehicle-mounted front-view lens 100 still has good imaging capability at the maximum image plane.

[0056] Figure 3 This is a defocus curve of the vehicle-mounted front-view lens 100 described in this embodiment at an ambient temperature of 25°C. Figure 3 It can be seen that the defocus amount of the vehicle-mounted front-view lens 100 in each field of view in the visible light band does not exceed 0.01mm, indicating that the vehicle-mounted front-view lens 100 basically achieves a non-defocus state in each field of view.

[0057] Figure 4 This is the relative illumination map of the main wavelength of the vehicle-mounted forward-looking lens 100 described in this embodiment, derived from... Figure 4 It can be seen that the relative illuminance of the main wavelength at the maximum image plane Φ9.3mm of the vehicle-mounted front-view lens 100 is greater than 75%, indicating that the brightness of the image image of the vehicle-mounted front-view lens 100 is uniform, which further improves the image quality.

[0058] Figure 5 This is a graph showing the field curvature and distortion of the vehicle-mounted forward-looking lens 100 in the visible light band, as described in this embodiment. Figure 5 It can be seen that the optical distortion of the vehicle-mounted forward-looking lens 100 has been well corrected, meeting the requirements for low distortion.

[0059] In summary, the maximum image plane of the vehicle-mounted forward-viewing lens 100 in this embodiment can reach 9.3mm, and under this field of view, the vehicle-mounted forward-viewing lens 100 still has high resolution, as well as the advantages of high illumination and low distortion.

[0060] This utility model also provides another effective specific embodiment of the vehicle-mounted forward-looking lens 100. In this embodiment, the vehicle-mounted forward-looking lens 100 includes a first lens 11, an aperture 4, a second lens 21, a third lens 22, a fourth lens 23, a fifth lens 24, a sixth lens 25, a protective glass 5, and an image plane 3, arranged sequentially from the object side to the image side along the optical axis. The image side and the object side of the protective glass 5 are both planar. The first lens 11 has a negative optical power, and the object side S1 is concave while the image side S2 is convex. The second lens 21 has a positive optical power, and its object-side surface S4 and image-side surface S5 are convex. The third lens 22 has a negative optical power, and its object-side surface S6 is flat and its image-side surface S7 is concave. The fourth lens 23 has a positive optical power, and its object-side surface S8 and image-side surface S9 are convex. The fifth lens 24 has a negative optical power, and its object-side surface S10 is convex and its image-side surface S11 is concave. The sixth lens 25 has a negative optical power, and its object-side surface S12 is concave and its image-side surface S13 is convex.

[0061] In this embodiment, the optical assembly of the vehicle-mounted forward-looking lens 100 is set to TTL, TTL=30.2mm, and the aperture number is set to FNO, FNO=1.6. The first lens 11, the third lens 22, the fifth lens 24, and the sixth lens 25 are set as high dispersion lenses with an Abbe number ≤50 dB. The refractive index Nd of the first lens 11, the third lens 22, the fourth lens 23, the fifth lens 24, and the sixth lens 25 is ≥1.6.

[0062] In this embodiment, the basic parameters of each lens of the vehicle-mounted forward-looking lens 100, including surface type, radius of curvature (mm), thickness (mm), material characteristics, and Conic value, are shown in Table 3: Table 3

[0063] As disclosed above, in this embodiment, the ratio of the focal length of the first lens 11 to the focal length of the vehicle-mounted front-view lens 100 is F1 / F = -25.303; the ratio of the focal length of the second lens 21 to the focal length of the vehicle-mounted front-view lens 100 is F2 / F = 0.997; the ratio of the focal length of the third lens 22 to the focal length of the vehicle-mounted front-view lens 100 is F3 / F = -0.934; the ratio of the focal length of the fourth lens 23 to the focal length of the vehicle-mounted front-view lens 100 is F4 / F = 0.786; the ratio of the focal length of the fifth lens 24 to the focal length of the vehicle-mounted front-view lens 100 is F5 / F = -2.977; and the ratio of the focal length of the sixth lens 25 to the focal length of the vehicle-mounted front-view lens 100 is F6 / F = -1.466.

[0064] In this embodiment, D1 / r2=-0.905; r5 / r4=-2.699; r7 / r6=0.000; r9 / r8=-1.761; r11 / r10=0.610; r13 / r12=2.075.

[0065] Furthermore, in this embodiment, the aspherical surface shape of the aspherical lens satisfies the following condition:

[0066] Where Z represents the distance of the surface from the vertex of the surface in the optical axis direction, parameter c is the curvature corresponding to the radius, y is the radial coordinate, and its unit is the same as the lens length unit, k is the conic quadratic coefficient; when the coefficient k is less than -1, the surface curve of the lens is a hyperbola, when the coefficient k is equal to -1, the surface curve of the lens is a parabola; when the coefficient k is between -1 and 0, the surface curve of the lens is an ellipse, when the coefficient k is equal to 0, the surface curve of the lens is a circle, when the coefficient k is greater than 0, the surface curve of the lens is an oval, and α1 to α8 represent the coefficients corresponding to each radial coordinate.

[0067] In this embodiment, the coefficients of the higher-order terms of each aspherical mirror are shown in Table 2 below: Table 2

[0068] It is understandable that number 4 is the object-side number of the second lens 21, and number 5 is the image-side number of the second lens 21.

[0069] This setup, by rationally allocating the lens power and adjusting the glass shape and material combination, effectively eliminates chromatic aberration and secondary spectrum, allowing spherical aberration, coma, astigmatism, etc. on each lens to compensate and cancel each other out, thereby achieving a clear imaging effect and realizing optimal correction of higher-order aberrations and chromatic aberration.

[0070] It should be noted that, Figure 7 This is the MTF curve of the vehicle-mounted forward-looking camera 100 described in this embodiment, derived from... Figure 7 It can be seen that the MTF value of the vehicle-mounted front-view lens 100 at the maximum image plane Φ9.3mm is above 0.3, indicating that the vehicle-mounted front-view lens 100 still has good imaging capability at the maximum image plane.

[0071] Figure 8 This is a defocus curve of the vehicle-mounted front-view lens 100 described in this embodiment at an ambient temperature of 25°C. Figure 8 It can be seen that the defocus amount of the vehicle-mounted front-view lens 100 in each field of view in the visible light band does not exceed 0.01mm, indicating that the vehicle-mounted front-view lens 100 basically achieves a non-defocus state in each field of view.

[0072] Figure 9 This is the relative illumination map of the main wavelength of the vehicle-mounted forward-looking lens 100 described in this embodiment, derived from... Figure 9 It can be seen that the relative illuminance of the main wavelength at the maximum image plane Φ9.3mm of the vehicle-mounted front-view lens 100 is greater than 75%, indicating that the brightness of the image image of the vehicle-mounted front-view lens 100 is uniform, which further improves the image quality.

[0073] Figure 10 This is a graph showing the field curvature and distortion of the vehicle-mounted forward-looking lens 100 in the visible light band, as described in this embodiment. Figure 10 It can be seen that the optical distortion of the vehicle-mounted forward-looking lens 100 has been well corrected, meeting the requirements for low distortion.

[0074] In summary, the maximum image plane of the vehicle-mounted forward-viewing lens 100 in this embodiment can also reach 9.3mm, and under this field of view, the vehicle-mounted forward-viewing lens 100 can also have high resolution, as well as the advantages of high illumination and low distortion.

[0075] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A vehicle-mounted forward-looking camera, characterized in that, The vehicle-mounted forward-looking lens comprises a first lens group with negative optical power, a second lens group with positive optical power, and an image plane, arranged sequentially from the object side to the image side along the optical axis. The lens satisfies the following conditions: -40 < F11 / F < -8, and 0 < F22 / F < 2.0; The focal length of the vehicle-mounted forward-looking lens is F, the focal length of the first lens group is F11, and the focal length of the second lens group is F12.

2. The vehicle-mounted forward-looking camera as described in claim 1, characterized in that, The first lens group includes a first lens with negative optical power. The first lens is configured as a glass spherical lens with a concave object side and a convex image side. The focal length of the first lens is F1, and -40 < F1 / F < -20.

3. The vehicle-mounted forward-looking camera as described in claim 2, characterized in that, The refractive index of the first lens is Nd1, where Nd1 ≥ 1.

5.

4. The vehicle-mounted forward-looking camera as described in claim 2, characterized in that, The aperture of the first lens is D1, and the radius of curvature near the image side is r2, -1.5 < D1 / r2 < -0.

5.

5. The vehicle-mounted forward-looking camera as described in claim 1, characterized in that, The second lens group includes a second lens with positive optical power, a third lens with negative optical power, a fourth lens with positive optical power, a fifth lens with negative optical power, and a sixth lens with negative optical power, arranged sequentially from the object side to the image side along the optical axis. The second lens is a glass aspherical lens, and the third, fourth, fifth, and sixth lenses are glass spherical lenses. The second lens group satisfies the following conditions: 0<F2 / F<1.5; -2<F3 / F<0; 0<F4 / F<1.5; -5<F5 / F<-1; -2.5<F6 / F<-0.5; The second lens has a focal length of F2, the third lens has a focal length of F3, the fourth lens has a focal length of F4, the fifth lens has a focal length of F5, and the sixth lens has a focal length of F6.

6. The vehicle-mounted forward-looking camera as described in claim 5, characterized in that, The object-side surface of the second lens is convex, and the image-side surface is also convex. The object-side surface of the third lens is flat, and the image-side surface is concave. The object-side surface of the fourth lens is convex, and the image-side surface is also convex. The object-side surface of the fifth lens is convex, and the image-side surface is concave. The object-side surface of the sixth lens is concave, and the image-side surface is convex.

7. The vehicle-mounted forward-looking camera as described in claim 5, characterized in that, The refractive index of the second lens is Nd2, 1.45≤Nd2≤1.6; The refractive index of the third lens is Nd3, 1.6≤Nd3≤1.8; The refractive index of the fourth lens is Nd4, 1.6≤Nd4≤1.8; The refractive index of the fifth lens is Nd5, where 1.45 ≤ Nd5 ≤ 1.8; The refractive index of the sixth lens is Nd6, where 1.6 ≤ Nd6 ≤ 1.

7.

8. The vehicle-mounted forward-looking lens as described in claim 5, characterized in that, The second lens has a radius of curvature of r4 near the object side and a radius of curvature of r5 near the image side, where -4≤r5 / r4≤-1.5; The radius of curvature of the third lens near the object side is r6, and the radius of curvature near the image side is r7, r7 / r6=0; The radius of curvature of the fourth lens near the object side is r8, and the radius of curvature near the image side is r9, where -3.0 ≤ r9 / r8 ≤ -1.0; The radius of curvature of the fifth lens near the object side is r10, and the radius of curvature near the image side is r11, where 0 ≤ r11 / r10 ≤ 1.5; The radius of curvature of the sixth lens near the object side is r12, and the radius of curvature near the image side is r13, where 1.5 ≤ r13 / r12 ≤ 3.

5.

9. The vehicle-mounted forward-looking lens as described in claim 5, characterized in that, The vehicle-mounted front-view lens also includes an anti-reflection coating, which is coated on the object-side surface of the third lens to reduce reflected light on the object-side surface of the third lens.

10. The vehicle-mounted forward-looking lens as described in any one of claims 1 to 9, characterized in that, The vehicle-mounted forward-looking lens also includes an aperture stop and a protective glass arranged sequentially from the object side to the image side along the optical axis. The aperture stop is located between the first lens group and the second lens group, and the protective glass is located on the side of the second lens group closer to the image plane.

Images