Vehicle-mounted wide-angle lens optical system

Abstract

The invention relates to a vehicle-mounted wide-angle lens optical system, and the system sequentially comprises a first lens with negative focal power from an object side to an image side along an optical axis, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the object side surface of the third lens is a convex surface, and the image side surface of the third lens is a concave surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a convex surface; the object side surface of the fifth lens is a concave surface or a convex surface, and the image side surface of the fifth lens is a concave surface; and the object side surface of the sixth lens is a convex surface, and the image side surface of the sixth lens is a convex surface. The invention has the beneficial effects of being capable of increasing the visual angle, low in distortion, high in pixel, excellent in temperature characteristic and capable of meeting day and night confocal.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging, and particularly to an in-vehicle wide-angle lens optical system. Background Art

[0002] In recent years, with the continuous popularization of intelligent driving, wide-angle lenses have been increasingly applied to various vehicles, playing an important role in fields such as driving record, safe driving, in-vehicle and out-of-vehicle monitoring, lane departure warning, pedestrian detection warning, etc. Subsequently, the performance requirements for lenses are also getting higher and higher, specifically manifested in the optical lens as features of low distortion, high definition resolution, and excellent temperature characteristics. However, due to the large field of view angle of the wide-angle lens, the distortion of the optical system is generally large and the image distortion is serious.

[0003] In addition, automobiles are used in harsh outdoor weather environments, and it is required that the in-vehicle lens can maintain stable imaging performance at different temperatures. Moreover, in relatively dark environments such as at night, most of the current in-vehicle imaging optical systems have the disadvantage of too low imaging brightness, unable to clearly distinguish the image, and it is difficult to meet the use requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide an in-vehicle wide-angle lens optical system that can increase the viewing angle, has low distortion, high pixels, excellent temperature characteristics, and meets day and night confocal requirements.

[0005] An in-vehicle wide-angle lens optical system sequentially includes, along the optical axis from the object side to the image side: a first lens with negative optical power, the object side of the first lens is convex, and the image side is concave; a second lens with negative optical power, the object side of the second lens is convex, and the image side is concave; a third lens with positive optical power, the object side of the third lens is convex, and the image side is concave; a fourth lens with positive optical power, the object side of the fourth lens is convex, and the image side is convex; a fifth lens with negative optical power, the object side of the fifth lens is concave or convex, and the image side is concave; a sixth lens with positive optical power, the object side of the sixth lens is convex, and the image side is convex; the first lens and the fourth lens are made of low-dispersion glass material, and the second lens, the third lens, the fifth lens, and the sixth lens are all made of low-dispersion plastic material.

[0006] By adopting the optimized design of the first lens to the sixth lens, the full field of view angle of the optical system can be expanded, large-angle image capture can be achieved, and at the same time, the performance of low distortion can be taken into account. The TV distortion of the system is lower than 19%. Moreover, a hybrid design scheme of glass materials and plastic materials is adopted, which is beneficial to correcting the temperature drift problem, so that the optical system does not defocus within the temperature range of -40°C to 80°C, avoiding the risk of defocusing during shooting in harsh environments, and is beneficial to further reducing the weight of the lens and making the lens more miniaturized. At the same time, by using low-dispersion materials, chromatic aberration can be effectively reduced, enabling the system to meet day-night confocal requirements, having excellent day-night dual-use performance, and expanding the usage range of the lens.

[0007] Further, the vehicle-mounted wide-angle lens optical system satisfies the following conditional expressions: -4.0 < f1 / f < -3.0, -3.3 < f2 / f < -2.3, 3.6 < f3 / f < 4.8, 1.5 < f4 / f < 2.5, -2.6 < f5 / f < -1.5, 1.0 < f6 / f < 2.0, where f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f is the focal length of the vehicle-mounted wide-angle lens optical system.

[0008] In the above solution, the first lens, the second lens, and the third lens are used as the front group, and the fourth lens, the fifth lens, and the sixth lens are used as the rear group. The optical powers of each lens have a reasonable distribution ratio. The first lens and the second lens of the front group work together, which is beneficial to reducing the angle between the light beam and the optical axis after passing through the front group of lenses, quickly reducing the light height, and entering the third lens at a reasonable height, preparing for further correcting aberration by the rear group and improving the lens resolution. At the same time, it is beneficial to increasing the field of view angle and achieving wide-angle imaging.

[0009] Further, the vehicle-mounted wide-angle lens optical system satisfies the following conditional expressions: 1.5 ≤ Nd1 ≤ 1.7, 50 ≤ Vd1 ≤ 70; 1.5 ≤ Nd2 ≤ 1.6, 50 ≤ Vd2 ≤ 60; 1.6 ≤ Nd3 ≤ 1.7, 20 ≤ Vd3 ≤ 25; 1.5 ≤ Nd4 ≤ 1.7, 60 ≤ Vd4 ≤ 80; 1.6 ≤ Nd5 ≤ 1.7, 20 ≤ Vd5 ≤ 25; 1.5 ≤ Nd6 ≤ 1.7, 50 ≤ Vd6 ≤ 60;

[0010] Wherein, Nd1 is the refractive index of the first lens, Vd1 is the dispersion coefficient of the first lens, Nd2 is the refractive index of the second lens, Vd2 is the dispersion coefficient of the second lens, Nd3 is the refractive index of the third lens, Vd3 is the dispersion coefficient of the third lens, Nd4 is the refractive index of the fourth lens, Vd4 is the dispersion coefficient of the fourth lens, Nd5 is the refractive index of the fifth lens, Vd5 is the dispersion coefficient of the fifth lens, Nd6 is the refractive index of the sixth lens, and Vd6 is the dispersion coefficient of the sixth lens.

[0011] In the above solution, the lens combination structure satisfying the above refractive index relationship is conducive to realizing reasonable distribution of optical power, and can better correct aberrations such as spherical aberration and field curvature, thereby improving the lens resolution. Moreover, the fourth lens is made of an ultra-low dispersion material, which can effectively reduce the axial chromatic aberration of the system, enabling the system to have a better infrared imaging effect without defocusing during the day and at night.

[0012] Furthermore, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: -8×10 -6 ≤dn / dt (L4) ≤-3×10 -6 , where dn / dt (L4) is the relative refractive index temperature coefficient of the fourth lens.

[0013] In the above solution, the fourth lens satisfying the above relational formula is conducive to the temperature correction of the athermalized system, and can more effectively balance the image plane drift amount of the optical system in high and low temperature states.

[0014] Furthermore, the first lens and the fourth lens are spherical lenses, and the second lens, the third lens, the fifth lens and the sixth lens are all aspherical lenses.

[0015] In the above solution, the second lens, the third lens, the fifth lens and the sixth lens are all aspherical lenses. Since the aspherical surface type has a large degree of freedom, the ability to deflect light and correct aberrations is significantly stronger than that of a spherical surface, which is conducive to improving the lens resolution and correcting lens distortion. At the same time, it is also conducive to correcting the exit light angle of the lens and can better match the photosensitive element.

[0016] Furthermore, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: D12 / R12 < 1.84, where D12 is the effective aperture of the image side of the first lens, and R12 is the curvature radius of the image side of the first lens.

[0017] In the above solution, by making the first lens satisfy the above conditional formula, the lens structure of the vehicle-mounted wide-angle lens can be made simple and compact, and the lens of the wide-angle lens can be ensured to have good optical performance and processing performance.

[0018] Furthermore, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: 0.1 < f / TTL < 0.25, where f is the focal length of the vehicle-mounted wide-angle lens optical system, and TTL is the on-axis distance from the object side surface of the first lens to the imaging surface.

[0019] In the above solution, the focal length of the vehicle-mounted wide-angle lens optical system and the on-axis distance from the object side surface of the first lens to the imaging surface satisfy the above relational formula, which can enable the optical system to maintain high imaging quality while effectively shortening the overall system length.

[0020] Furthermore, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: 0.15 < BFL / TTL < 0.25, where BFL is the on-axis distance from the image side surface of the sixth lens to the imaging surface, and TTL is the on-axis distance from the object side surface of the first lens to the imaging surface.

[0021] In the above solution, by making the optical system satisfy the above conditional formula, it is beneficial to ensure the optical performance of the system while restricting the overall optical length of the system.

[0022] Furthermore, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: DFOV > 115°, where DFOV is the full field of view angle of the vehicle-mounted wide-angle lens optical system.

[0023] In the above solution, through the optimized design of the first lens, the second lens, the third lens, and the fourth lens, the full field of view angle of the optical system can reach more than 115°, and the TV distortion of the system is lower than 19%. This optical system can achieve a large full field of view angle while maintaining a small overall size, and can also take into account the low distortion performance.

[0024] Furthermore, it further includes a diaphragm, and the diaphragm is arranged between the first lens and the second lens.

[0025] In the above solution, by arranging the diaphragm between the first lens and the second lens, with such a setting, it is beneficial to increase the field of view angle of the wide-angle lens optical system, and at the same time, it can better balance the exit angle of the optical system, which is further beneficial to matching the corresponding image sensor, and can also ensure the improvement of imaging quality while satisfying a shorter system length.

[0026] An in-vehicle wide-angle lens optical system of the present invention has beneficial effects of being able to increase the viewing angle, having low distortion, excellent temperature characteristics, and meeting day-night co-focus. Through the optimized design of the first lens to the sixth lens, the full field of view angle of the optical system can be expanded, realizing large-angle image capture. At the same time, the performance of low distortion can also be taken into account. The TV distortion of the system is lower than 19%. Moreover, a mixed design scheme of glass materials and plastic materials is adopted, which is beneficial to correcting the temperature drift problem, making the optical system not defocus within the temperature range of -40°C to 80°C, avoiding the risk of defocus during shooting in harsh environments, and being beneficial to further reducing the weight of the lens and being more conducive to the miniaturization of the lens. At the same time, by using low-dispersion materials, chromatic aberration can be effectively reduced, enabling the system to meet day-night co-focus, having excellent day-night dual-use performance, and expanding the use range of the lens. Brief Description of the Drawings

[0027] Figure 1 It is a structural diagram of the in-vehicle wide-angle lens 1 in Embodiment 1.

[0028] Figure 2 It is a field curvature distortion diagram of the in-vehicle wide-angle lens 1 in Embodiment 1.

[0029] Figure 3 It is a defocus MTF curve diagram of the in-vehicle wide-angle lens 1 in Embodiment 1 at room temperature of 20°C.

[0030] Figure 4 It is a defocus MTF curve diagram of the in-vehicle wide-angle lens 1 in Embodiment 1 at low temperature of -40°C.

[0031] Figure 5 It is a defocus MTF curve diagram of the in-vehicle wide-angle lens 1 in Embodiment 1 at high temperature of 80°C.

[0032] Figure 6 It is an infrared light defocus MTF curve diagram of the in-vehicle wide-angle lens 1 in Embodiment 1.

[0033] Figure 7 It is a structural diagram of the in-vehicle wide-angle lens 2 in Embodiment 2.

[0034] Figure 8 It is a field curvature distortion diagram of the in-vehicle wide-angle lens 2 in Embodiment 2.

[0035] Figure 9 It is a defocus MTF curve diagram of the in-vehicle wide-angle lens 2 in Embodiment 2 at room temperature of 20°C.

[0036] Figure 10 It is a defocus MTF curve diagram of the in-vehicle wide-angle lens 2 in Embodiment 2 at low temperature of -40°C.

[0037] Figure 11It is the defocus MTF curve graph of the vehicle-mounted wide-angle lens 2 in Example 2 at a high temperature of 80°C.

[0038] Figure 12 It is the infrared light defocus MTF curve graph of the vehicle-mounted wide-angle lens 2 in Example 2.

[0039] Figure 13 It is the structural diagram of the vehicle-mounted wide-angle lens 3 in Example 3.

[0040] Figure 14 It is the field curvature and distortion graph of the vehicle-mounted wide-angle lens 3 in Example 3.

[0041] Figure 15 It is the defocus MTF curve graph of the vehicle-mounted wide-angle lens 3 in Example 3 at a normal temperature of 20°C.

[0042] Figure 16 It is the defocus MTF curve graph of the vehicle-mounted wide-angle lens 3 in Example 3 at a low temperature of -40°C.

[0043] Figure 17 It is the defocus MTF curve graph of the vehicle-mounted wide-angle lens 3 in Example 3 at a high temperature of 80°C.

[0044] Figure 18 It is the infrared light defocus MTF curve graph of the vehicle-mounted wide-angle lens 3 in Example 3.

[0045] Figure 19 It is the structural diagram of the vehicle-mounted wide-angle lens 4 in Example 4.

[0046] Figure 20 It is the field curvature and distortion graph of the vehicle-mounted wide-angle lens 4 in Example 4.

[0047] Figure 21 It is the defocus MTF curve graph of the vehicle-mounted wide-angle lens 4 in Example 4 at a normal temperature of 20°C.

[0048] Figure 22 It is the defocus MTF curve graph of the vehicle-mounted wide-angle lens 4 in Example 4 at a low temperature of -40°C.

[0049] Figure 23 It is the defocus MTF curve graph of the vehicle-mounted wide-angle lens 4 in Example 4 at a high temperature of 80°C.

[0050] Figure 24 It is the infrared light defocus MTF curve graph of the vehicle-mounted wide-angle lens 4 in Example 4.

[0051] Explanation of the reference numerals in the drawings: L1, the first lens; L2, the second lens; L3, the third lens; L4, the fourth lens; L5, the fifth lens; L6, the sixth lens; STO, the aperture stop; BPF: the band-pass filter; IMA: the imaging surface. Detailed implementation manners

[0052] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0053] The on-vehicle wide-angle lens optical system involved in this embodiment is composed of six lenses, with a simple structure and a small volume. By combining different-structured lenses and reasonably distributing the optical powers of each lens, it can ensure a sufficient field of view, has excellent temperature characteristics, and is particularly suitable for on-vehicle monitoring systems.

[0054] The basic structure of the on-vehicle wide-angle lens optical system involved in this embodiment will be described.

[0055] As Figures 1 to 24 shown, in a preferred embodiment, an on-vehicle wide-angle lens optical system includes, in order along the optical axis from the object side to the image side: a first lens L1 with a negative optical power, the object side of the first lens L1 is convex, and the image side is concave; a second lens L2 with a negative optical power, the object side of the second lens L2 is convex, and the image side is concave; a third lens L3 with a positive optical power, the object side of the third lens L3 is convex, and the image side is concave; a fourth lens L4 with a positive optical power, the object side of the fourth lens L4 is convex, and the image side is convex; a fifth lens L5 with a negative optical power, the object side of the fifth lens L5 is concave or convex, and the image side is concave; a sixth lens L6 with a positive optical power, the object side of the sixth lens L6 is convex, and the image side is convex; the first lens L1 and the fourth lens L4 are made of low-dispersion glass material, and the second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6 are all made of low-dispersion plastic material.

[0056] By adopting the optimized design of the first lens L1 to the sixth lens L6, the full field of view angle of the optical system can be expanded, large-angle image capture can be achieved, and at the same time, the performance of low distortion can be taken into account. The TV distortion of the system is less than 19%. Moreover, a hybrid design scheme of glass material and plastic material is adopted, which is beneficial to correcting the temperature drift problem, so that the optical system does not defocus within the temperature range of -40°C to 80°C, avoiding the risk of defocus during shooting in harsh environments, and is beneficial to further reducing the weight of the lens and making the lens more miniaturized. At the same time, by using low-dispersion materials, chromatic aberration can be effectively reduced, enabling the system to meet day-night confocal, having excellent day-night dual-use performance, and expanding the usage range of the lens.

[0057] In addition, there are more lenses made of plastic material, which is beneficial to further reducing the weight of the lens and making the lens more miniaturized.

[0058] As shown in the figure, in some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional expressions: -4.0 < f1 / f < -3.0, -3.3 < f2 / f < -2.3, 3.6 < f3 / f < 4.8, 1.5 < f4 / f < 2.5, -2.6 < f5 / f < -1.5, 1.0 < f6 / f < 2.0, where f1 is the focal length of the first lens L1, f2 is the focal length of the second lens L2, f3 is the focal length of the third lens L3, f4 is the focal length of the fourth lens L4, f5 is the focal length of the fifth lens L5, f6 is the focal length of the sixth lens L6, and f is the focal length of the vehicle-mounted wide-angle lens optical system. The first lens L1, the second lens L2, and the third lens L3 serve as the front group, and the fourth lens L4, the fifth lens L5, and the sixth lens L6 serve as the rear group. The optical powers of the respective lenses have a reasonable distribution ratio. The first lens L1 and the second lens L2 of the front group act together, which is conducive to reducing the angle between the light beam and the optical axis after passing through the front group of lenses, rapidly reducing the light height, and incident on the third lens L3 at a reasonable height, preparing for further correcting aberrations by the rear group to improve the lens resolution. At the same time, it is conducive to increasing the field of view angle and achieving wide-angle imaging.

[0059] As Figures 1 to 24 shown, in some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional expressions: 1.5 ≤ Nd1 ≤ 1.7, 50 ≤ Vd1 ≤ 70; 1.5 ≤ Nd2 ≤ 1.6, 50 ≤ Vd2 ≤ 60; 1.6 ≤ Nd3 ≤ 1.7, 20 ≤ Vd3 ≤ 25; 1.5 ≤ Nd4 ≤ 1.7, 60 ≤ Vd4 ≤ 80; 1.6 ≤ Nd5 ≤ 1.7, 20 ≤ Vd5 ≤ 25; 1.5 ≤ Nd6 ≤ 1.7, 50 ≤ Vd6 ≤ 60; where Nd1 is the refractive index of the first lens L1, Vd1 is the dispersion coefficient of the first lens L1, Nd2 is the refractive index of the second lens L2, Vd2 is the dispersion coefficient of the second lens L2, Nd3 is the refractive index of the third lens L3, Vd3 is the dispersion coefficient of the third lens L3, Nd4 is the refractive index of the fourth lens L4, Vd4 is the dispersion coefficient of the fourth lens L4, Nd5 is the refractive index of the fifth lens L5, Vd5 is the dispersion coefficient of the fifth lens L5, Nd6 is the refractive index of the sixth lens L6, and Vd6 is the dispersion coefficient of the sixth lens L6.

[0060] The lens combination structure satisfying the above refractive index relationship is conducive to achieving a reasonable distribution of optical power, and can better correct aberrations such as spherical aberration and field curvature, thereby improving the lens resolution. Moreover, the fourth lens L4 is made of an ultra-low dispersion material, which can effectively reduce the axial chromatic aberration of the system, enabling the system to have a better infrared imaging effect and no defocus during the day and at night.

[0061] As Figures 1 to 24As shown, in some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: -8×10 -6 ≤dn / dt (L4) ≤-3×10 -6 , where dn / dt (L4) is the relative refractive index temperature coefficient of the fourth lens L4. The fourth lens L4 that satisfies the above relational formula is beneficial to the temperature correction of the athermalization system and can more effectively balance the image plane drift amount of the optical system in high and low temperature states.

[0062] As Figures 1 to 24 shown, in some embodiments, the first lens L1 and the fourth lens L4 are spherical lenses, and the second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6 are all aspherical lenses. The second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6 are all aspherical lenses. Due to the large degree of freedom of the aspherical surface type, the deflection of light and the correction ability of aberration are significantly stronger than those of the spherical surface, which is beneficial to improving the lens resolution and correcting lens distortion. At the same time, it is also beneficial to correct the exit light angle of the lens and can better match the photosensitive element.

[0063] As Figures 1 to 24 shown, in some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: D12 / R12 < 1.84, where D12 is the effective aperture of the image side of the first lens L1, and R12 is the curvature radius of the image side of the first lens L1. By making the first lens L1 satisfy the above conditional formula, the lens structure of the vehicle-mounted wide-angle lens can be made simple and compact, and the lens of the wide-angle lens can be ensured to have good optical performance and processing performance.

[0064] As Figures 1 to 24 shown, in some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: 0.1 < f / TTL < 0.25, where f is the focal length of the vehicle-mounted wide-angle lens optical system, and TTL is the on-axis distance from the object side of the first lens L1 to the imaging plane. When the focal length of the vehicle-mounted wide-angle lens optical system and the on-axis distance from the object side of the first lens L1 to the imaging plane satisfy the above relational formula, the optical system can maintain a high imaging quality while effectively shortening the total length of the system.

[0065] As Figures 1 to 24 shown, in some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: 0.15 < BFL / TTL < 0.25, where BFL is the on-axis distance from the image side of the sixth lens L6 to the imaging plane, and TTL is the on-axis distance from the object side of the first lens L1 to the imaging plane. By making the optical system satisfy the above conditional formula, it is beneficial to ensure the optical performance of the system while restricting the total optical length of the system.

[0066] AsFigures 1 to 24 As shown, in some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: DFOV > 115°, where DFOV is the full field of view angle of the vehicle-mounted wide-angle lens optical system. Through the optimized design of the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4, the full field of view angle of the optical system can reach more than 115°, while the TV distortion of the system is lower than 19%. This optical system can achieve a large full field of view angle while maintaining a small overall size, and can also take into account the low distortion performance.

[0067] As Figures 1 to 24 shown, in some embodiments, a diaphragm is further included, and the diaphragm is disposed between the first lens L1 and the second lens L2. By configuring the diaphragm between the first lens L1 and the second lens L2, such a setting is beneficial to increasing the field of view angle of the wide-angle lens optical system, and can also better balance the exit angle of the optical system, thereby facilitating matching with the corresponding image sensor, and can also ensure improving the imaging quality while satisfying a short system length. The aperture can achieve FNO ≤ 2.3, the light input of the lens is large, and the imaging brightness is high.

[0068] In some embodiments, the vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: TTL < 12.6 mm, where TTL is the on-axis distance from the object side surface of the first lens L1 to the imaging surface. In addition to ensuring that f / TTL is greater than 0.1 and less than 0.25, it is also necessary to ensure that TTL, that is, the on-axis distance from the object side surface of the first lens L1 to the imaging surface, is less than 12.6 mm, which is beneficial to ensuring the optical performance of the system while limiting the total optical length of the system.

[0069] For a vehicle-mounted wide-angle lens optical system of the present invention, through the optimized design of the above-mentioned first lens L1 to the sixth lens L6, the horizontal field of view angle can reach more than 115°, achieving image capture at a large angle, and the maximum image plane diameter can reach 6.8 mm; at the same time, it takes into account the low distortion performance, the TV distortion of the system is lower than 9%, the image deformation is small, and the imaging picture is more real.

[0070] By using a large number of aspherical surfaces, the system aberration is well corrected, and high-definition imaging of 5 million pixels can be achieved, and the total optical length of the optical system is less than 15.2 mm, with a small volume, which is beneficial to realizing the miniaturization of the lens.

[0071] Adopting a mixed design scheme of glass materials and plastic materials is beneficial to correcting the temperature drift problem, so that the optical system does not defocus within the temperature range of -40°C to 80°C, avoiding the risk of defocus during shooting in harsh environments. At the same time, by using low-dispersion materials, chromatic aberration can be effectively reduced, enabling the system to meet day and night confocal, having excellent day and night dual-use performance, and expanding the use range of the lens.

[0072] In various embodiments of the present invention, when the lens has an aspherical surface profile, the aspherical surface profiles of the optical lens satisfy the following relational expression:

[0073]

[0074] In the formula, Z is the distance between the surface and the vertex of the surface in the optical axis direction, the parameter c is the curvature corresponding to the radius of the lens, y is the radial coordinate, k is the conic coefficient, and a4, a6, a8, a10, a12, a14, a16 are the surface coefficients corresponding to the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order radial coordinates respectively.

[0075] Next, for the vehicle-mounted wide-angle lens, embodiments will be listed and described in detail with reference to the accompanying drawings.

[0076] Embodiment 1

[0077] The design parameters of the optical system of the vehicle-mounted wide-angle lens in this embodiment can be shown in the following table:

[0078] Table 1-1

[0079]

[0080]

[0081] In the above table, the units of the surface radius and thickness are both millimeters; the surface marked with "*" represents an aspherical surface, and the surface profile of the aspherical lens satisfies the following relational expression:

[0082] The aspherical surface profile parameters of the vehicle-mounted wide-angle lens 1 in this embodiment are shown in Table 1-2:

[0083] Table 1-2:

[0084]

[0085]

[0086] Figure 2 is the field curvature and distortion diagram of the vehicle-mounted wide-angle lens 1 in this embodiment. Figure 3 、 Figure 4 、 Figure 5 respectively represent the defocus MTF curve diagrams of the vehicle-mounted wide-angle lens 1 in this embodiment at room temperature of 20 °C, at low temperature of -40 °C, and at high temperature of 80 °C. Figure 6 is the infrared light defocus MTF curve diagram of the vehicle-mounted wide-angle lens 1 in this embodiment.

[0087] From Figure 2 it can be seen that the field of view angle reaches 129°, and the optical distortion is controlled within -20%, indicating that the distortion of the vehicle-mounted wide-angle lens 1 is well corrected and the image deformation is small.

[0088] From Figures 3 to 5 it can be seen that in the temperature range of -40°C to 80°C, the temperature drift is small, indicating that the on-vehicle wide-angle lens 1 has excellent performance in harsh environments of low temperature and high temperature.

[0089] From Figure 6 it can be seen that the infrared defocus is small, indicating that the on-vehicle wide-angle lens 1 has excellent day and night performance and does not defocus during the day and at night.

[0090] Embodiment 2

[0091] Figure 7 is the structural diagram of the on-vehicle wide-angle lens 2 of this embodiment. Compared with Embodiment 1, the main difference lies in that the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0092] In this embodiment, the horizontal field of view HFOV of the on-vehicle wide-angle lens 2 is 118.3° and the FNO is 2.3.

[0093] The relevant parameters of each lens in the on-vehicle wide-angle lens 1 in this embodiment are shown in Table 2-1.

[0094] Table 2-1

[0095]

[0096]

[0097] In Table 2-1, the surface marked with "*" represents an aspherical surface.

[0098] The aspherical surface type parameters of the on-vehicle wide-angle lens 2 in this embodiment are shown in Table 2-2.

[0099] Table 2-2

[0100]

[0101] Figure 8 is the field curvature and distortion diagram of the on-vehicle wide-angle lens 2 of this embodiment. Figure 9 、 Figure 10 、 Figure 11 respectively represent the defocus MTF curve graphs of the on-vehicle wide-angle lens 2 of this embodiment at normal temperature of 20°C, at low temperature of -40°C, and at high temperature of 80°C. Figure 12 is the infrared light defocus MTF curve graph of the on-vehicle wide-angle lens 2 of this embodiment.

[0102] From Figure 8 it can be seen that the field of view angle reaches 129.1° and the optical distortion is controlled within -20%, indicating that the distortion of the on-vehicle wide-angle lens 2 is well corrected and the image deformation is small.

[0103] It can be seen from Figures 9 to 11 that within the temperature range of -40°C to 80°C, the temperature drift is small, indicating that the on-vehicle wide-angle lens 2 has excellent performance in harsh environments of low temperature and high temperature.

[0104] It can be seen from Figure 12 that the infrared defocus is small, indicating that the on-vehicle wide-angle lens 2 has excellent day and night performance and does not defocus during the day and at night.

[0105] Embodiment 3

[0106] Figure 13 is the structural diagram of the on-vehicle wide-angle lens 3 in this embodiment. Compared with Embodiment 1, the main differences are that the object side of the fifth lens L5 is convex and the optical parameters such as the curvature radius and lens thickness of each lens surface are different.

[0107] In this embodiment, the horizontal field of view HFOV of the on-vehicle wide-angle lens 3 is 119° and the FNO is 2.3.

[0108] The relevant parameters of each lens in the on-vehicle wide-angle lens 3 in this embodiment are shown in Table 3-1.

[0109] Table 3-1

[0110]

[0111] In Table 3-1, the surface marked with "*" represents an aspherical surface.

[0112] The aspherical surface type parameters of the on-vehicle wide-angle lens 3 in this embodiment are shown in Table 3-2.

[0113] Table 3-2

[0114]

[0115] Figure 14 is the field curvature and distortion diagram of the on-vehicle wide-angle lens 3 in this embodiment. Figure 15 , Figure 16 , Figure 17 respectively represent the defocus MTF curve diagrams of the on-vehicle wide-angle lens 3 in this embodiment at normal temperature of 20°C, at low temperature of -40°C, and at high temperature of 80°C. Figure 18 is the infrared light defocus MTF curve diagram of the on-vehicle wide-angle lens 3 in this embodiment.

[0116] It can be seen from Figure 14 that the field of view angle reaches 129° and the optical distortion is controlled within -20%, indicating that the distortion of the on-vehicle wide-angle lens 3 is well corrected and the image deformation is small.

[0117] It can be seen from Figures 15 to 17It can be seen that in the temperature range of -40°C to 80°C, the temperature drift is small, indicating that the on-vehicle wide-angle lens 3 has excellent performance in harsh environments of low temperature and high temperature.

[0118] From Figure 18 it can be seen that the infrared defocus is small, indicating that the on-vehicle wide-angle lens 3 has excellent day and night performance and does not defocus during the day and at night.

[0119] Embodiment 4

[0120] Figure 19 is the structural diagram of the on-vehicle wide-angle lens 4 of this embodiment. Compared with Embodiment 1, the main differences are that the object side of the fifth lens L5 is convex and the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0121] In this embodiment, the horizontal field of view HFOV of the on-vehicle wide-angle lens 4 is 118.9° and the FNO is 2.3.

[0122] The relevant parameters of each lens in the on-vehicle wide-angle lens 4 of this embodiment are shown in Table 4-1.

[0123] Table 4-1

[0124]

[0125]

[0126] In Table 4-1, the surface marked with "*" represents an aspherical surface.

[0127] The aspherical surface type parameters of the on-vehicle wide-angle lens 4 of this embodiment are shown in Table 4-2. Table 4-1

[0128]

[0129]

[0130] Figure 20 is the field curvature and distortion diagram of the on-vehicle wide-angle lens 4 of this embodiment. Figure 21 , Figure 22 , Figure 23 respectively represent the defocus MTF curve graphs of the on-vehicle wide-angle lens 4 of this embodiment at normal temperature of 20°C, at low temperature of -40°C, and at high temperature of 80°C. Figure 24 is the infrared light defocus MTF curve graph of the on-vehicle wide-angle lens 4 of this embodiment.

[0131] From Figure 20 it can be seen that the field of view angle reaches 129°, and the optical distortion is controlled within -20%, indicating that the distortion of the on-vehicle wide-angle lens 4 is well corrected and the image deformation is small.

[0132] From Figures 21 to 23 It can be seen that in the temperature range of -40°C to 80°C, the temperature drift is small, indicating that the on-vehicle wide-angle lens 4 has excellent performance in harsh environments of low temperature and high temperature.

[0133] From Figure 24 It can be seen that the infrared defocus is small, indicating that the on-vehicle wide-angle lens 4 has excellent day and night performance, without defocusing during the day and at night.

[0134] Referring to Table 5, it shows the optical characteristics corresponding to the above-mentioned embodiments, including the effective focal length f of the optical lens, the total optical length TTL, the relative refractive index temperature coefficient dn / dt (L4) of the fourth lens, and the values corresponding to each conditional formula in the embodiments.

[0135] Table 5

[0136]

[0137]

[0138] Combining the above embodiments, the on-vehicle wide-angle lens provided by the present invention realizes the effects of large field of view, low distortion, high pixel, short total length, low temperature drift, and infrared confocal by reasonably matching the surface shapes and optical power combinations of each lens and selecting appropriate lens materials.

[0139] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0140] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0141] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "coupled", "fixed", etc. shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0142] Although the description of the present invention is made in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications, and variations based on the above content. Therefore, all such substitutions, improvements, and variations are included within the spirit and scope of the appended claims.

Claims

1. A vehicle-mounted wide-angle lens optical system, characterized in that, From the object side to the image side along the optical axis, it successively includes: A first lens with negative optical power, the object side of the first lens is convex, and the image side is concave; A second lens with negative optical power, the object side of the second lens is convex, and the image side is concave; A third lens with positive optical power, the object side of the third lens is convex, and the image side is concave; A fourth lens with positive optical power, the object side of the fourth lens is convex, and the image side is convex; A fifth lens with negative optical power, the object side of the fifth lens is concave or convex, and the image side is concave; A sixth lens with positive optical power, the object side of the sixth lens is convex, and the image side is convex; The first lens and the fourth lens are made of low-dispersion glass material, and the second lens, the third lens, the fifth lens and the sixth lens are all made of low-dispersion plastic material.

2. The vehicle-mounted wide-angle lens optical system according to claim 1, characterized in that, The vehicle-mounted wide-angle lens optical system satisfies the following conditional expressions: -4.0 < f1 / f < -3.0, -3.3 < f2 / f < -2.3, 3.6 < f3 / f < 4.8, 1.5 < f4 / f < 2.5, -2.6 < f5 / f < -1.5, 1.0 < f6 / f < 2.0, Wherein, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, and f is the focal length of the vehicle-mounted wide-angle lens, and f is the focal length of the vehicle-mounted wide-angle lens optical system.

3. The vehicle-mounted wide-angle lens optical system according to claim 1, wherein The vehicle-mounted wide-angle lens optical system satisfies the following conditional expressions: 1.5 ≤ Nd1 ≤ 1.7, 50 ≤ Vd1 ≤ 70; 1.5 ≤ Nd2 ≤ 1.6, 50 ≤ Vd2 ≤ 60; 1.6 ≤ Nd3 ≤ 1.7, 20 ≤ Vd3 ≤ 25; 1.5 ≤ Nd4 ≤ 1.7, 60 ≤ Vd4 ≤ 80; 1.6 ≤ Nd5 ≤ 1.7, 20 ≤ Vd5 ≤ 25; 1.5 ≤ Nd6 ≤ 1.7, 50 ≤ Vd6 ≤ 60; Wherein, Nd1 is the refractive index of the first lens, Vd1 is the dispersion coefficient of the first lens, Nd2 is the refractive index of the second lens, Vd2 is the dispersion coefficient of the second lens, Nd3 is the refractive index of the third lens, Vd3 is the dispersion coefficient of the third lens, Nd4 is the refractive index of the fourth lens, Vd4 is the dispersion coefficient of the fourth lens, Nd5 is the refractive index of the fifth lens, Vd5 is the dispersion coefficient of the fifth lens, Nd6 is the refractive index of the sixth lens, and Vd6 is the dispersion coefficient of the sixth lens.

4. The vehicle-mounted wide-angle lens optical system according to claim 1, characterized in that, The vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: -8×10 -6 ≤dn / dt (L4) ≤-3×10 -6 , where dn / dt (L4) is the relative refractive index temperature coefficient of the fourth lens.

5. The vehicle-mounted wide-angle lens optical system according to claim 1, wherein The first lens and the fourth lens are spherical lenses, and the second lens, the third lens, the fifth lens and the sixth lens are all aspherical lenses.

6. The vehicle-mounted wide-angle lens optical system according to claim 1, wherein, The vehicle-mounted wide-angle lens optical system satisfies the following conditional expression: D12 / R12 < 1.84, where D12 is the effective aperture of the image side of the first lens, and R12 is the radius of curvature of the image side of the first lens.

7. The vehicle-mounted wide-angle lens optical system according to claim 1, characterized in that The vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: 0.1 < f / TTL < 0.15, where f is the focal length of the vehicle-mounted wide-angle lens optical system, and TTL is the axial distance from the object side surface of the first lens to the imaging surface.

8. The vehicle-mounted wide-angle lens optical system according to claim 7, characterized in that The vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: 0.15 < BFL / TTL < 0.25, where BFL is the axial distance from the image side surface of the sixth lens to the imaging surface, and TTL is the axial distance from the object side surface of the first lens to the imaging surface.

9. The vehicle-mounted wide-angle lens optical system according to claim 1, characterized in that The vehicle-mounted wide-angle lens optical system satisfies the following conditional formula: DFOV > 115°, where DFOV is the full field of view angle of the vehicle-mounted wide-angle lens optical system.

10. The vehicle-mounted wide-angle lens optical system according to claim 1, characterized in that, It is characterized in that An aperture is provided between the third lens and the fourth lens.

Images