An ultra-wide-angle high-definition surround-view camera lens and an imaging method thereof

Abstract

The present application relates to the technical field of lens, especially to an ultra-wide-angle high-definition surround view camera lens and an imaging method thereof, the optical system of the lens is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens arranged in sequence from the object side to the image side along the light incident path, wherein the fourth lens and the fifth lens are cemented lens groups; without considering the reverse bending caused by the aspherical surface coefficient, the first lens is a meniscus concave negative lens, the object side surface of which is a convex surface and the image side surface of which is a concave surface; the second lens is a meniscus concave negative lens, the object side surface of which is a convex surface and the image side surface of which is a concave surface; the third lens is a double-convex positive lens, the object side surface of which is a convex surface and the image side surface of which is a convex surface; the fourth lens is a double-convex positive lens, the object side surface of which is a convex surface and the image side surface of which is a convex surface; the fifth lens is a double-concave negative lens, the object side surface of which is a concave surface and the image side surface of which is a concave surface; and the sixth lens is a double-convex positive lens, the object side surface of which is a convex surface and the image side surface of which is a convex surface. The lens helps to realize ultra-wide-angle imaging while realizing small size and high resolution imaging, and reduces the cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lenses, in particular to an ultra-wide-angle high-definition surround view camera lens and an imaging method thereof. BACKGROUND

[0002] With the increasing number of vehicles in cities, traffic is becoming more and more congested, and the existing blind area of the driver's view in the vehicle makes the vehicle prone to collision, friction and other accidents when driving at low speed. People realize the importance of reducing or even eliminating the blind area of the driver's view, and the vehicle-mounted surround view system emerges as the times require. The vehicle-mounted surround view system can collect real-time image information through multiple wide-angle lens camera modules around the vehicle, and stitch them into an overhead image covering a 360° range around the vehicle, effectively reducing the blind area of the driver's view. However, the use of multiple lenses greatly increases the cost of building a vehicle-mounted surround view system, which is not conducive to the popularization and promotion of the system. SUMMARY

[0003] The purpose of the present application is to provide an ultra-wide-angle high-definition surround view camera lens and an imaging method thereof, which helps to realize small size and high resolution imaging while realizing ultra-wide-angle imaging and reducing cost.

[0004] The technical solution of the present application is as follows: an ultra-wide-angle high-definition surround view camera lens, the optical system of the lens is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens arranged in order along the light incident path from the object side to the image side, wherein the fourth lens and the fifth lens are cemented lens groups; without considering the reverse curvature caused by the aspherical coefficient, the first lens is a meniscus concave negative lens, the object side surface of which is convex, and the image side surface of which is concave; the second lens is a meniscus concave negative lens, the object side surface of which is convex, and the image side surface of which is concave; the third lens is a double-convex positive lens, the object side surface of which is convex, and the image side surface of which is convex; the fourth lens is a double-convex positive lens, the object side surface of which is convex, and the image side surface of which is convex; the fifth lens is a double-concave negative lens, the object side surface of which is concave, and the image side surface of which is concave; the sixth lens is a double-convex positive lens, the object side surface of which is convex, and the image side surface of which is convex; each lens is made of glass material, the second lens and the sixth lens are glass aspherical lenses, and the first lens, the third lens, the fourth lens and the fifth lens are glass spherical lenses.

[0005] Further, the focal length of the optical system is , 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 , , , , , , wherein , , 、 、 、 and satisfy the following ratios: -6.0 / -5.0, -2.0 / -1.0, 2.0 / <3.0, 2.0 / <3.0, -2.0 / -1.0, 2.0 / <3.0.

[0006] Further, the first lens satisfies the relationship: 2.0≤ ≤2.5, ≤50.0; the second lens satisfies the relationship: 1.5≤ ≤1.8, ≤50.0; the third lens satisfies the relationship: 1.7≤ ≤2.0, ≤50.0; the fourth lens satisfies the relationship: 1.5≤ ≤1.8, ≥50.0; the fifth lens satisfies the relationship: 1.7≤ ≤2.0, ≤50.0; the sixth lens satisfies the relationship: 1.5≤ ≤1.8, ≤50.0; wherein is the refractive index, is the Abbe number.

[0007] Further, the axial distance between each lens satisfies the following relationships: the air gap between the first lens and the second lens is: 3.0~3.5mm; the air gap between the second lens and the third lens is: 1.5~2.0mm; the air gap between the third lens and the diaphragm is: 0.1~0.5mm; the air gap between the diaphragm and the fourth lens is: 0.5~1.0mm; the fourth lens and the fifth lens are cemented lenses, the air gap is 0mm; the air gap between the fifth lens and the sixth lens is: 0.1~0.5mm.

[0008] Further, the aspherical curve equation expression of the second lens and the sixth lens is:

[0009]

[0010] Wherein, Z is the sagittal height of the aspherical surface from the vertex of the aspherical surface at a position with a height of h along the optical axis; c is the paraxial curvature of the aspherical surface; k is the conic constant; All are high order term coefficients.

[0011] Further, the total track length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤15.0.

[0012] Further, the F number of the optical system is ≤2.0.

[0013] Further, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0014] Further, a filter is arranged on the image side of the sixth lens.

[0015] An imaging method of the super-wide-angle high-definition surround-view camera lens, a super-wide-angle high-definition surround-view camera lens, light rays pass through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens and the filter in turn from the object side to the image side and then are imaged on the image plane.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] 1. The lens helps to realize super-wide-angle imaging while realizing small volume and high resolution imaging, so that a panoramic surround-view system is realized with fewer lenses, and the cost is reduced.

[0018] 2. The lens has an imaging angle of more than 200 degrees for an object, and has the advantages of high imaging clarity, large light aperture, low tolerance sensitivity and good high-low temperature stability, and can more comprehensively monitor the scene outside the vehicle.

[0019] 3. By reasonably matching each optical lens, the system structure is compact and reasonable, easy to assemble, low in tolerance sensitivity, and more suitable for large-scale high-yield production.

[0020] 4. The all-glass structure has high operating environment stability, and makes good compensation for the focal plane displacement at high and low temperatures, and has complex environment adaptability.

[0021] 5. The axial color difference, the sagittal color difference and the high-order color difference are corrected, so that the imaging system can also have high imaging quality at a large angle. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the optical structure schematic diagram of the present application;

[0023] Figure 2is the full working waveband axial chromatic aberration diagram of the present application;

[0024] Figure 3 is the full working waveband sagittal chromatic aberration diagram of the present application;

[0025] Figure 4 is the full working waveband field curvature distortion diagram of the present application;

[0026] 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; L8- equivalent glass flat plate; IMA- imaging surface. DETAILED DESCRIPTION

[0027] In order to make the above features and advantages of the present application more apparent, the following specific examples are described in detail below, together with the accompanying drawings, as follows, but the present application is not limited thereto.

[0028] Reference Figures 1 to 4

[0029] An ultra-wide-angle high-definition surround-view camera lens, the optical system of the lens is composed of a first lens L1, a second lens L2, a third lens L3, a stop STO, a fourth lens L4, a fifth lens L5 and a sixth lens L6 arranged in sequence from the object side to the image side along the light incident path, wherein the fourth lens and the fifth lens are cemented lens groups; without considering the reverse bending caused by the aspherical coefficient, the first lens is a meniscus concave negative lens, the object side surface of which is convex, and the image side surface of which is concave; the second lens is a meniscus concave negative lens, the object side surface of which is convex, and the image side surface of which is concave; the third lens is a double-convex positive lens, the object side surface of which is convex, and the image side surface of which is convex; the fourth lens is a double-convex positive lens, the object side surface of which is convex, and the image side surface of which is convex; the fifth lens is a double-concave negative lens, the object side surface of which is concave, and the image side surface of which is concave; the sixth lens is a double-convex positive lens, the object side surface of which is convex, and the image side surface of which is convex; each lens is made of glass material, the second lens and the sixth lens are glass aspherical lenses, and the first lens, the third lens, the fourth lens and the fifth lens are glass spherical lenses.

[0030] In this embodiment, the first lens and the second lens are lenses with negative focal power, which adjust the large-angle light at the same time, and the aspherical lens has the effect of reducing the distortion of the optical system. The fourth lens and the fifth lens form an achromatic double-cemented lens. Reasonable lens matching makes the optical system achieve ultra-wide-angle, large-aperture, day and night focus, low-temperature drift design. At the same time, the on-axis and off-axis aberrations are well corrected, and the imaging quality is good, as shown in Figures 2 to 4 .

[0031] In this embodiment, the focal length of the optical system is focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are respectively , , , , , wherein , , , , , and satisfy the following ratios: -6.0 / <-5.0, -2.0 / <-1.0, 2.0 / <3.0, 2.0 / <3.0, -2.0 / <-1.0, 2.0 / <3.0.

[0032] In this embodiment, the first lens satisfies the relationship: 2.0≤ ≤2.5, ≤50.0; the second lens satisfies the relationship: 1.5≤ ≤1.8, ≤50.0; the third lens satisfies the relationship: 1.7≤ ≤2.0, ≤50.0; the fourth lens satisfies the relationship: 1.5≤ ≤1.8, ≥50.0; the fifth lens satisfies the relationship: 1.7≤ ≤2.0, ≤50.0; the sixth lens satisfies the relationship: 1.5≤ ≤1.8, ≤50.0; wherein is the refractive index, is the Abbe number.

[0033] In the embodiment, the on-axis distance between each lens satisfies the following relationship, the air gap between the first lens and the second lens is 3.0-3.5mm; the air gap between the second lens and the third lens is 1.5-2.0mm; the air gap between the third lens and the diaphragm is 0.1-0.5mm; the air gap between the diaphragm and the fourth lens is 0.5-1.0mm; the fourth lens and the fifth lens are cemented lenses, and the air gap is 0mm; the air gap between the fifth lens and the sixth lens is 0.1-0.5mm. In the case of meeting the imaging requirements, reducing the distance between each lens is beneficial to the total length of the lens.

[0034] In the embodiment, the aspherical surface curve equation expression of the second lens and the sixth lens is:

[0035]

[0036] 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; are high-order coefficients.

[0037] In the embodiment, the total length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤15.0. The image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0038] In the embodiment, a filter L8 is further arranged on the image side of the sixth lens.

[0039] In the embodiment, the technical indicators achieved by the optical system are as follows:

[0040] (1) focal length: 1.0≤EFFL≤2.0mm;

[0041] (2) aperture: F≤2.0;

[0042] (3) field of view: 2w≥200°;

[0043] (4) working waveband: visible light waveband.

[0044] In the embodiment, to achieve the above design parameters, the specific design of the optical system is shown in the following table:

[0045] .

[0046] The aspherical surface coefficients of each aspherical lens of the optical system of the embodiment are as follows:

[0047] .

[0048] In the embodiment, the optical system meets the requirements of small size and 200-degree super wide-angle imaging while meeting the imaging performance requirements of the lens by reasonably distributing the focal power, surface type, central thickness of each lens and the axial distance between each lens.

[0049] An imaging method of a super wide-angle high-definition surround view camera lens and a super wide-angle high-definition surround view camera lens, light rays from the object side to the image side sequentially pass through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens, and the filter to form an image on the image plane.

[0050] The above only describes the preferred embodiments of the present application, and for those skilled in the art, according to the teaching of the present application, it does not need creative labor to design different forms of super wide-angle high-definition surround view camera lens, and any equivalent changes, modifications, replacements and variations made within the scope of the present application should be covered by the present application.

Claims

1. An ultra-wide high-definition surround view camera lens, characterized in that, The optical system of the lens is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the light path of the incident light from the object side to the image side, wherein the fourth lens and the fifth lens form a cemented lens group; without considering the reverse bending caused by the aspherical surface coefficient, the first lens is a meniscus concave negative lens, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; the second lens is a meniscus concave negative lens, the object side surface of which is a convex surface, and the image side surface of which is a concave surface; the third lens is a double-convex positive lens, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; the fourth lens is a double-convex positive lens, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; the fifth lens is a double-concave negative lens, the object side surface of which is a concave surface, and the image side surface of which is a concave surface; and the sixth lens is a double-convex positive lens, the object side surface of which is a convex surface, and the image side surface of which is a convex surface; each lens is made of glass material, the second lens and the sixth lens are glass aspherical lenses, the first lens, the third lens, the fourth lens and the fifth lens are glass spherical lenses, and the number of lenses with optical power in the lens is 6; 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: -6.0 < f1 / f < -5.0, -2.0 < f2 / f < -1.0, 2.0 < f3 / f < 3.0, 2.0 < f4 / f < 3.0, -2.0 < f5 / f < -1.0, and 2.0 < f6 / f < 3.0; the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f ≤ 15.0; the F number of the optical system is ≤ 2.0; and the image height H of the optical system and the focal length f of the optical system satisfy: H / f ≥ 1.

0. 2.The ultra-wide high-definition surround view camera lens according to claim 1, wherein, The first lens satisfies the relationship: 2.0 ≤ N d ≤ 2.5, 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: 1.7 ≤ N d ≤ 2.0, 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 ultra-wide high-definition surround view camera lens according to claim 1, wherein, The axial distance between each lens satisfies the following relationship: the air gap between the first lens and the second lens is 3.0-3.5 mm; the air gap between the second lens and the third lens is 1.5-2.0 mm; the air gap between the third lens and the diaphragm is 0.1-0.5 mm; the air gap between the diaphragm and the fourth lens is 0.5-1.0 mm; the fourth lens and the fifth lens form a cemented lens group, and the air gap is 0 mm; and the air gap between the fifth lens and the sixth lens is 0.1-0.5 mm.

4. The ultra-wide high-definition surround view camera lens according to claim 1, wherein, The aspherical surface curve equation expression of the second lens and the sixth lens is: 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; α1, α2, α3, α4, α5, α6, α7 and α8 are high-order coefficients, and r = 1 / c.

5. The ultra-wide high-definition surround view camera lens according to claim 1, wherein, A filter is arranged on the image side of the sixth lens.

6. An imaging method of an ultra-wide high-definition surround view camera lens, characterized in that, The super-wide-angle high-definition surround view camera lens comprises the lens according to claim 5, and light rays sequentially pass through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens and the filter from the object side to the image side to form an image.

Images