A large-aperture athermal high-definition vehicle-mounted lens

Abstract

The present application relates to a kind of high-definition vehicle-mounted lenses, the optical system of the lens is by first lens, second lens, third lens, fourth lens, fifth lens and sixth lens in turn from left to right along the light path of light incidence is formed, diaphragm is arranged between third lens and fourth lens.Wherein first lens, second lens, fifth lens and sixth lens are glass spherical lens, third lens, fourth lens are glass aspherical lens.By reasonably distributing the optical power of each lens, surface type, the center thickness of each lens and the on-axis distance between each lens etc., while meeting the requirements of large-aperture high-definition imaging performance of lens, it has good thermal stability, can also high-definition imaging under working temperature-40 DEG C to 105 DEG C, can adapt to complex and changeable driving environment;And system structure is reasonable, assembly tolerance sensitivity is low, more suitable for large-scale high-yield mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging technology, and particularly relates to a large-aperture athermal high-definition vehicle-mounted lens. BACKGROUND

[0002] With the rapid development of intelligent vehicles, the advanced driver assistance system technology is constantly improving. As an important part of the intelligent driving system, the demand for vehicle-mounted camera lenses is increasing day by day, and the requirements for the imaging performance of vehicle-mounted lenses are also becoming higher and higher.

[0003] Due to the high safety performance requirement of vehicles, the camera lenses carried need to have high resolving power, small aberration and low distortion, so that the road environment can be more accurately distinguished and the misjudgment in the driving process can be reduced, effectively preventing road safety hazards. At the same time, the use environment of vehicles is complex and changeable, and the optical lens carried needs a large light aperture to ensure sufficient light flux and imaging clarity under different light environments, and requires strong environmental reliability to ensure good resolving power in high-temperature or low-temperature environments. However, most of the vehicle-mounted lenses used on the market cannot meet the above technical requirements. Therefore, vehicle-mounted lenses with high resolving power, large aperture, low distortion and athermalization meet the trend of future development. SUMMARY

[0004] In view of the shortcomings of the prior art, the purpose of the present application is to provide a large-aperture athermal high-definition vehicle-mounted lens, which has the advantages of large aperture, high resolving power and athermalization.

[0005] The present application provides a large-aperture athermal high-definition vehicle-mounted lens, which includes, in order from the object side to the image side along the optical axis: a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens.

[0006] The first lens is a double-concave lens with negative focal power, the object side is concave, and the image side is concave. The second lens is a double-convex positive lens with positive focal power, the object side is convex, and the image side is convex. The third lens is a negative meniscus lens with negative focal power, the object side is convex, and the image side is concave. The fourth lens is a double-convex positive lens with positive focal power, both the object side and the image side are convex. The fifth lens is a double-convex positive lens with positive focal power, both the object side and the image side are convex. The sixth lens is a double-concave lens with negative focal power, both the object side and the image side are concave. All the lenses are made of glass material, wherein the first lens, the second lens, the fifth lens and the sixth lens are glass spherical lenses, the third lens and the fourth lens are glass aspherical lenses, and the fifth and sixth lenses are cemented lens groups.

[0007] Preferably, the focal length of the optical system is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are f1, f2, f3, f4, f5 and f6 respectively, wherein f1, f2, f3, f4, f5 and f6 satisfy the following ratios: -2.0 < f1 / f < -1.0, 2.0 < f2 / f < 3.0, -5.0 < f3 / f < -4.0, 1.0 < f4 / f < 2.0, 1.0 < f5 / f < 2.0, and -1.0 < f6 / f < 0.

[0008] Preferably, the first lens satisfies the relationship: 1.8 ≤ N d ≤ 2.0, and V d ≤ 50.0; the second lens satisfies the relationship: 1.8 ≤ N d ≤ 2.0, and V d ≤ 50.0; the third lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≥ 50.0; the fourth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≥ 50.0; the fifth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≥ 50.0; and the sixth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, and V d ≤ 50.0; wherein N d is the refractive index, and V d is the Abbe number.

[0009] Preferably, the distance between each lens on the optical axis satisfies the following relationships: the air gap between the first lens and the second lens is 4.5-5.0 mm; the air gap between the second lens and the third lens is 0.1-0.5 mm; the air gap between the third lens and the diaphragm is 1.0-1.5 mm; the air gap between the diaphragm and the fourth lens is -0.1-0 mm; the air gap between the fourth lens and the fifth lens is 0-0.1 mm; and the fifth lens and the sixth lens are a cemented lens group with an air gap of 0 mm.

[0010] Preferably, the third lens and the fourth lens are both aspherical lenses, and the aspherical curve equation is expressed as:

[0011]

[0012] wherein Z is the sagittal height of the aspherical surface at a height of h along the optical axis from the vertex of the aspherical surface; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5 and α6 are high-order coefficients.

[0013] Preferably, the total track length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤7.

[0014] Preferably, the F number of the optical system is ≤1.7.

[0015] Preferably, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0016] Preferably, the rear side of the sixth lens is provided with a filter.

[0017] Compared with the prior art, the present application has the following advantages:

[0018] The vehicle-mounted lens provided by the present application adopts six optical glass lenses, and is composed of four glass spherical lenses and two glass aspherical lenses to form an optical imaging system, and has the advantages of high resolution, small temperature drift, small chromatic aberration, and strong aberration correction capability.

[0019] 1. By reasonably setting the refractive power of the six lenses, the lens has a field of view angle of 80 degrees, and can realize large-range picture monitoring; meanwhile, the lens has a large light aperture, so that the lens has high imaging clarity under different illumination environments in the daytime or at night, and can more comprehensively monitor the scene outside the vehicle.

[0020] 2. By reasonably matching the optical lenses, the system structure is compact and reasonable, easy to assemble, low in tolerance sensitivity, and more suitable for large-scale high-yield production.

[0021] 3. The all-glass lenses are adopted, so that the lens has good thermal stability, can make good compensation for the focal plane displacement at high and low temperatures, and has complex environment adaptability.

[0022] 4. Meanwhile, by reasonably matching and setting the surface shapes of the spherical lenses and the aspherical lenses, the axial chromatic aberration, the sagittal chromatic aberration, and the high-order chromatic aberration are effectively corrected, so that the imaging system can also have high imaging quality at a large angle.

[0023] The present application will be further described in detail below in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic diagram of the optical structure of the present application;

[0025] Figure 2 is a sagittal chromatic aberration diagram of the full working waveband of the present application;

[0026] Figure 3 is an axial chromatic aberration diagram of the full working waveband of the present application;

[0027] Figure 4 is a field curvature distortion diagram of the full working waveband of the present application;

[0028] Figure 5 is the full working waveband MTF curve diagram of the present application;

[0029] In the figure: STO- stop; L1- first lens; L2- second lens; L3- third lens; L4- fourth lens; L5- fifth lens; L6- sixth lens; L7- equivalent glass flat plate; IMA- imaging plane. DETAILED DESCRIPTION

[0030] The present application is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0031] As shown in Figure 1 , a vehicle-mounted optical lens is provided, which is sequentially provided with a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side, and a stop is arranged between the third lens and the fourth lens, wherein the first lens, the second lens, the fifth lens and the sixth lens are all glass spherical lenses, and the third lens and the fourth lens are glass aspherical lenses; the first lens has a negative focal power, and the object side surface and the image side surface thereof can both be concave surfaces; the first lens is provided in a double-concave shape, which is beneficial to adjusting the light rays at a large angle, so that the light rays at a large angle can enter the optical system as much as possible, thereby increasing the light throughput; the second lens has a positive focal power, and the object side surface and the image side surface thereof are both convex surfaces; the third lens has a negative focal power, and the object side surface thereof is a convex surface and the image side surface thereof is a concave surface; the reasonable arrangement of the second lens and the third lens is beneficial to converging the light rays passing through the first lens and smoothly transitioning the light rays into the rear lens, while effectively correcting the system aberration; the stop is arranged between the third lens and the fourth lens, which can balance the positive and negative focal powers of the lens groups before and after the stop, effectively reduce the distortion of the optical system, and improve the resolving power of the edge field of view of the lens; the fourth lens has a positive focal power, and the object side surface and the image side surface thereof are both convex surfaces; the fifth lens has a positive focal power, and the object side surface and the image side surface thereof are both convex surfaces; the sixth lens has a negative focal power, and the object side surface and the image side surface thereof are both concave surfaces; the fifth lens and the sixth lens are designed as achromatic double cemented lenses, which can effectively reduce the chromatic aberration, so that the on-axis chromatic aberration is controlled to be within 20 um, and the off-axis chromatic aberration is controlled to be within 6 um.

[0032] As shown in Figures 2 to 5 , through the reasonable lens matching described above, the aberration in the optical system is effectively corrected, so that the optical lens has a high resolution, good imaging performance, and realizes a large aperture, day and night confocal and non-thermal design.

[0033] The technical indicators realized by the optical system of the present embodiment are as follows:

[0034] (1) focal length: 5.0≤EFFL≤6.0mm;

[0035] (2) Focal ratio F≤1.7;

[0036] (3) Field of view: 2w≥80°;

[0037] (4) Working waveband: visible waveband and short wave infrared waveband.

[0038] To realize the above design parameters, the specific design of the optical system of the embodiment is shown in the following table:

[0039]

[0040] The aspheric coefficients of each aspheric lens of the optical system of the embodiment are shown in the following table:

[0041]

[0042] The optical system of the embodiment, by reasonably distributing the focal power, surface shape, central thickness of each lens, and axial distance between each lens, etc., while meeting the imaging performance requirements of the lens, has a large light aperture, good thermal stability, strong environmental reliability, and can adapt to complex and variable driving environments; and the system structure is reasonable, the assembly tolerance sensitivity is low, and is more suitable for large-scale high-yield production.

[0043] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technical content to equivalent embodiments. However, any simple modification, equivalent change and modification made according to the technical essence of the present application to the above embodiments, without departing from the technical solution content of the present application, still falls within the protection scope of the present application.

Claims

1. A high aperture, athermalized, high definition vehicle lens, characterized in that: The lens comprises, in order from the object side to the image side along the optical axis, a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, and a sixth lens; the number of lenses with optical power in the lens is 6, the focal length of the lens is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are f1, f2, f3, f4, f5, and f6, respectively, wherein f1, f2, f3, f4, f5, and f6 and f satisfy the following ratios: -2.0 < f1 / f < -1.0, 2.0 < f2 / f < 3.0, -5.0 < f3 / f < -4.0, 1.0 < f4 / f < 2.0, 1.0 < f5 / f < 2.0, and -1.0 < f6 / f < 0; the total optical length TTL of the lens and the focal length f of the lens satisfy: TTL / f ≤ 7; the F number of the lens is ≤ 1.7; the image height H of the lens and the focal length f of the lens satisfy: H / f ≥ 1.0; the rear side of the sixth lens of the lens is provided with a filter; and the technical indexes realized by the lens are as follows: (1) focal length: 5.0 mm ≤ f ≤ 6.0 mm; (2) aperture F number ≤ 1.7; (3) field of view angle ≥ 80°; (4) working waveband: visible light waveband and short-wave infrared waveband; The first lens is a double-concave lens with negative optical power, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; the second lens is a double-convex positive lens with positive optical power, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; the third lens is a negative meniscus lens with negative optical power, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; the fourth lens is a double-convex positive lens with positive optical power, both the object side surface and the image side surface of which are convex surfaces; the fifth lens is a double-convex positive lens with positive optical power, both the object side surface and the image side surface of which are convex surfaces; and the sixth lens is a double-concave lens with negative optical power, both the object side surface and the image side surface of which are concave surfaces; all the lenses are made of glass material, wherein the first lens, the second lens, the fifth lens, and the sixth lens are glass spherical surface lenses, the third lens and the fourth lens are glass aspherical surface lenses, and the fifth lens and the sixth lens form a cemented lens group. 2.The high definition vehicle lens with large aperture and free from heat according to claim 1, wherein: The first lens satisfies the relationship: 1.8 ≤ N d ≤ 2.0, V d ≤ 50.0; the second lens satisfies the relationship: 1.8 ≤ N d ≤ 2.0, V d ≤ 50.0; the third lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≥ 50.0; the fourth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≥ 50.0; the fifth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≥ 50.0; the sixth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≤ 50.0; wherein N d is the refractive index, and V d is the Abbe number. 3.The high definition vehicle lens with large aperture and free from heat according to claim 2, characterized in that: The distance between each lens of the lens on the optical axis satisfies the following relationship: the air gap between the first lens and the second lens is 4.5-5.0 mm; the air gap between the second lens and the third lens is 0.1-0.5 mm; the air gap between the third lens and the diaphragm is 1.0-1.5 mm; the air gap between the diaphragm and the fourth lens is -0.1-0 mm; the air gap between the fourth lens and the fifth lens is 0-0.1 mm; the fifth lens and the sixth lens form a cemented lens group, and the air gap is 0 mm. 4.The high definition vehicle lens with large aperture and free from heat according to claim 3, characterized in that: The third lens and the fourth lens of the lens are aspherical surface lenses, and the aspherical curve equation expression is as follows: wherein Z is the sagittal height of the aspherical surface at a height of h along the optical axis from the vertex of the aspherical surface; c is the paraxial curvature of the aspherical surface; r is 1 / c; k is the conic constant; and α1, α2, α3, α4, α5, and α6 are high-order coefficients.

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