Vehicle-mounted foresight optical lens and working method thereof

Abstract

The invention relates to a vehicle-mounted foresight optical lens and a working method thereof, an optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from left to right along a light incident light path, and a diaphragm is arranged between the second lens and the third lens. Wherein the first lens, the second lens, the third lens, the fourth lens and the fifth lens are glass spherical lenses, and the sixth lens is a glass aspheric lens. The system has the advantages of high resolution, large aperture, large field angle, low temperature drift and the like by reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the axial distance between the lenses and the like, and can meet the requirements of a vehicle-mounted automatic driving system.

Description

Technical Field

[0001] This invention relates to the field of lens technology, and in particular to a vehicle-mounted forward-looking optical lens and its working method. Background Technology

[0002] With the rapid development and widespread application of autonomous driving technology, vehicle cameras, as core sensors for environmental perception, are increasingly becoming crucial to system safety due to their imaging performance and reliability. Forward-facing cameras, in particular, bear the important responsibility of capturing real-time road conditions ahead. Their imaging quality directly affects the accuracy and timeliness of obstacle recognition, path planning, and driving decisions, forming a fundamental link in ensuring driving safety. However, some widely used forward-facing cameras still have significant limitations: overall image resolution is low, depth of field is limited, and it is difficult to achieve an effective balance between capturing distant details and maintaining wide-angle coverage. This insufficient imaging capability prevents the system from conducting comprehensive, high-precision real-time monitoring of the vehicle's surroundings, thus creating potential driving risks and failing to meet the increasingly stringent perception requirements of advanced autonomous driving systems. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a vehicle-mounted forward-looking lens with a large field of view, a large aperture and a high resolution, and a method for its operation, so as to meet the needs of autonomous driving.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] A vehicle-mounted forward-looking optical lens, characterized in that: the optical system of the lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from left to right along the incident light path; an aperture stop is disposed between the second lens and the third lens; without considering the curvature caused by the aspherical coefficient, the first lens is a meniscus negative lens with a convex object-side surface and a concave image-side surface; the second lens is a meniscus negative lens with a concave object-side surface and a convex image-side surface; the third lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; the fourth lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; the fifth lens is a meniscus negative lens with a concave object-side surface and a convex image-side surface; the sixth lens is a meniscus positive lens with a convex object-side surface and a concave image-side surface; the lenses are made of glass material, wherein the first, second, third, fourth, and fifth lenses are spherical glass lenses, the sixth lens is an aspherical glass lens, and the fourth and fifth lenses form a cemented lens group.

[0006] Preferably, the focal length of the optical system is f, and the focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are f1, f2, f3, f4, f5, and f6, respectively, wherein f1, f2, f3, f4, f5, and f6 satisfy the following ratio with f: -2.0 <f1 / f<-1.0,-8.0<f2 / f<-7.0,2.0<f3 / f<3.0,1.0<f4 / f<2.0,-2.0<f5 / f<-1.0,3.0<f6 / f<4.0。

[0007] Preferably, the first lens satisfies the relationship: 1.8 ≤ N d ≤2.0, V d ≤50.0; The second lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; The third lens satisfies the relationship: 1.7≤N d ≤2.0, 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: 1.8≤N d ≤2.1, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; where N d V is the refractive index. d Let be Abbe's constant.

[0008] Preferably, the on-axis distances between the lenses satisfy the following relationships: the air gap between the first lens and the second lens is 2.5–3.0 mm; the air gap between the second lens and the aperture stop is 0.0–0.5 mm; the air gap between the aperture stop and the third lens is 0.0–0.5 mm; the air gap between the third lens and the fourth lens is 1.5–2.0 mm; the fourth lens and the fifth lens are a cemented lens group with an air gap of 0 mm; and the air gap between the fifth lens and the sixth lens is 1.0–1.5 mm.

[0009] Preferably, the sixth lens is an aspherical lens. The equation for the aspherical curve is:

[0010]

[0011] Where z is the sag of the aspherical surface at a height of r 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; α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0012] Preferably, the total optical length (TTL) of the optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 7.0.

[0013] Preferably, the F-number of the optical system is ≤1.9.

[0014] Preferably, the image height H of the optical system and the focal length f of the optical system satisfy the following relationship: H / f≥1.1.

[0015] Preferably, the aperture of the optical system is located between the second lens and the third lens.

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

[0017] A method for operating a vehicle-mounted forward-looking optical lens, characterized in that: incident light rays pass sequentially from left to right through a first lens, a second lens, an aperture stop, a third lens, a fourth lens, a fifth lens, a sixth lens, a first equivalent glass plate, and a second equivalent glass plate, and form an image on the imaging surface of the second equivalent glass plate.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. This lens has an imaging angle of more than 135 degrees and features high imaging clarity, large aperture, low tolerance sensitivity and good high and low temperature stability, enabling more comprehensive monitoring of the scene outside the vehicle.

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

[0021] 3. By using only one glass aspherical lens, costs are reduced while adapting to different environments;

[0022] 4. It can effectively compensate for focal plane displacement at high and low temperatures, and has adaptability to complex environments;

[0023] 5. The chromatic aberration along each axis, the transverse chromatic aberration, and higher-order chromatic aberrations have been corrected to ensure that the imaging system can maintain high imaging quality even at large angles.

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the optical structure of the present invention;

[0026] Figure 2 This is the axial chromatic aberration diagram of the entire working band of the present invention;

[0027] Figure 3This is the transverse chromatic aberration diagram of the entire working band of the present invention;

[0028] Figure 4 This is the field curvature distortion diagram of the entire working band of the present invention;

[0029] In the diagram: STO - aperture stop; L1 - first lens; L2 - second lens; L3 - third lens; L4 - fourth lens; L5 - fifth lens; L6 - sixth lens; L7 - first equivalent glass plate; L8 - second equivalent glass plate; IMA - imaging plane. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific implementation methods.

[0031] like Figure 1 As shown, a vehicle-mounted forward-looking optical lens is provided with a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a first equivalent glass plate, and a second equivalent glass plate in sequence from the object side to the image side, and an aperture is disposed between the second lens and the third lens; the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all glass spherical lenses, and the sixth lens is a glass aspherical lens.

[0032] The first lens is a meniscus negative lens with a convex object side and a concave image side; the second lens is a meniscus negative lens with a concave object side and a convex image side; the third lens is a biconvex positive lens with a convex object side and a convex image side; the fourth lens is a biconvex positive lens with a convex object side and a convex image side; the fifth lens is a meniscus negative lens with a concave object side and a convex image side; and the sixth lens is a meniscus positive lens with a convex object side and a concave image side. All lenses are made of glass, with the first, second, third, fourth, and fifth lenses being spherical glass lenses, the sixth lens being an aspherical glass lens, and the fourth and fifth lenses being a cemented lens group.

[0033] The first and second lenses are both lenses with negative optical power. While adjusting for large-angle light, they can pre-correct aberrations, while the aspherical glass lens reduces optical system distortion. The fourth and fifth lenses form an achromatic cemented doublet. This reasonable lens combination enables the optical system to achieve an ultra-wide field of view, large aperture, and low temperature drift design, while effectively correcting on-axis and off-axis aberrations, resulting in good image quality. Figures 2 to 4 As shown.

[0034] The sixth lens is an aspherical lens, and the equation for the aspherical curve is:

[0035]

[0036] Where z is the sag of the aspherical surface at a height of r 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; α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

[0037] The technical specifications of the optical system implemented in one embodiment of this application are as follows:

[0038] (1) Focal length: 3.0≤EFFL≤4.0mm;

[0039] (2) Aperture F≤1.9;

[0040] (3) Field of view: 2w ≥ 135°;

[0041] (4) Operating band: Visible light band.

[0042] To achieve the above design parameters, the specific design of the optical system adopted in this embodiment is shown in the table below:

[0043]

[0044]

[0045] The aspherical coefficients of the aspherical lens in the optical system of this embodiment are shown in the table below:

[0046]

[0047] The optical system in this embodiment achieves advantages such as high resolution, large aperture, high resolution, and large field of view by rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis distance between each lens, thus meeting the needs of automotive autonomous driving systems.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A vehicle-mounted forward-looking optical lens, characterized in that: The optical system of the lens consists of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from left to right along the incident light path. An aperture stop is positioned between the second and third lenses. Ignoring the curvature caused by aspherical coefficients, the first lens is a meniscus negative lens with a convex object-side surface and a concave image-side surface; the second lens is a meniscus negative lens with a concave object-side surface and a convex image-side surface; the third lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; the fourth lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; the fifth lens is a meniscus negative lens with a concave object-side surface and a convex image-side surface; and the sixth lens is a meniscus positive lens with a convex object-side surface and a concave image-side surface. The lenses are made of glass, with the first, second, third, fourth, and fifth lenses being spherical glass lenses, and the sixth lens being an aspherical glass lens. The fourth and fifth lenses form a cemented lens group.

2. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: The optical system has a focal length of f, and the focal lengths of the first, second, third, fourth, fifth, and sixth lenses are f1, f2, f3, f4, f5, and f6, respectively, wherein f1, f2, f3, f4, f5, and f6 satisfy the following ratio with f: -2.0 <f1 / f<-1.0,-8.0<f2 / f<-7.0,2.0<f3 / f<3.0,1.0<f4 / f<2.0,-2.0<f5 / f<-1.0,3.0<f6 / f<4.0。 3. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: The first lens satisfies the following relationship: 1.8 ≤ N d ≤2.0, V d ≤50.0; The second lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; The third lens satisfies the relationship: 1.7≤N d ≤2.0, 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: 1.8≤N d ≤2.1, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; where N d V is the refractive index. d Let be Abbe's constant.

4. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: The on-axis distances between the lenses of the lens satisfy the following relationships: the air gap between the first lens and the second lens is 2.5-3.0 mm; the air gap between the second lens and the aperture stop is 0.0-0.5 mm; the air gap between the aperture stop and the third lens is 0.0-0.5 mm; the air gap between the third lens and the fourth lens is 1.5-2.0 mm; the fourth lens and the fifth lens are a cemented lens group with an air gap of 0 mm; and the air gap between the fifth lens and the sixth lens is 1.0-1.5 mm.

5. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: The sixth lens is an aspherical lens, and the equation of its aspherical curve is expressed as follows: Where z is the sag of the aspherical surface at a height of r 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; α1, α2, α3, α4, α5, α6, α7, and α8 are all higher-order coefficients.

6. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: The total optical length (TTL) of the optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 7.

0.

7. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: The F-number of the optical system is ≤1.9; the image height H of the optical system and the focal length f of the optical system satisfy the condition: H / f≥1.

1.

8. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: A filter is provided on the rear side of the sixth lens.

9. The vehicle-mounted forward-looking optical lens according to claim 1, characterized in that: The optical system achieves the following technical specifications: focal length: 3.0 ≤ EFFL ≤ 4.0 mm; aperture F ≤ 1.9; field of view: 2w ≥ 135°; operating wavelength: visible light band; the specific design of the optical system to achieve the above design parameters is shown in the table below: The aspherical coefficients of the aspherical lens in the optical system are shown in the table below: 。 10. A method for operating a vehicle-mounted forward-looking optical lens as described in any one of claims 1-9, characterized in that: The incident light rays pass sequentially from left to right through the first lens, the second lens, the aperture stop, the third lens, the fourth lens, the fifth lens, the sixth lens, the first equivalent glass plate, and the second equivalent glass plate, and are imaged on the imaging surface of the second equivalent glass plate.

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