8m vehicle-mounted forward-looking main camera and imaging method thereof

Abstract

The application relates to an 8M vehicle-mounted front-view main camera, and 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, a sixth lens and a seventh lens which are sequentially arranged along the light incident path from left to right; the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a double-convex positive lens, the fourth lens is a double-convex positive lens, the fifth lens is a negative lens, and the sixth lens is a double-convex positive lens. While realizing the visual perception and recognition function of driving, 8MP imaging is realized, so that the front-view wide-angle camera and the front-view narrow-angle camera can be replaced, a front-view camera module is formed by a single lens, the cost is greatly reduced, and the market popularity is improved. By reasonably distributing the optical power, surface type, center thickness of each lens and the axial distance between the lenses, the total length of the lens and the radial size of each lens are reduced, and the lens group is miniaturized.

Description

TECHNICAL FIELD

[0001] The application relates to an 8M vehicle-mounted front-view main camera and an imaging method thereof, and relates to the technical field of lenses. BACKGROUND

[0002] Functions of a vehicle-mounted front-view camera system mainly include two aspects: one is used for recording a driving track, and used as one of important bases for responsibility judgment after a traffic accident occurs; and the other is used for assisting driving, which can prevent lane deviation of a vehicle during driving and avoid collision with pedestrians on a road, so that the occurrence of traffic accidents can be effectively reduced. Therefore, the vehicle-mounted front-view camera system is an important hardware terminal in a high-level driving assistance system. Traditional vehicle-mounted front-view camera modules on the market can be divided into three structures: a front-view main camera, a front-view wide-angle camera and a front-view narrow-angle camera. As the names imply, adoption of the three cameras greatly increases the cost of the whole camera module, which is not conducive to popularization of the market. SUMMARY

[0003] In view of the deficiencies of the prior art, the application aims to provide an 8M vehicle-mounted front-view main camera and an imaging method thereof.

[0004] In order to solve the above technical problems, the technical scheme of the application is as follows: an 8M vehicle-mounted front-view main camera, an optical system of a lens of which is composed of a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged along an incident light path of light rays from left to right; wherein the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a double-convex positive lens, the fourth lens is a double-convex positive lens, the fifth lens is a negative lens, and the sixth lens is a double-convex positive lens.

[0005] Preferably, the focal length of the optical system is set as f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are respectively f1, f2, f3, f4, f5, f6 and f7, wherein f1, f2, f3, f4, f5, f6 and f7 and f satisfy the following proportions: -2.5 < f1 / f < -1.5, -5.0 < f2 / f < -3.0, 2.0 < f3 / f < 2.5, 1.5 < f4 / f < 2.0, -1.5 < f5 / f < -1.0, 1.5 < f6 / f < 3.0, and -8.0 < f7 / f < 122.0.

[0006] Preferably, the first lens satisfies the relationship: 1.7 < N d ≤ 2.0 and V d ≤ 50.0; the second lens satisfies the relationship: 1.7 < N d ≤ 2.0 and V d ≤ 50.0; and 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; the seventh lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; wherein N d is the refractive index, V d is the Abbe number.

[0007] Preferably, the lenses are made of glass material, and the fourth lens and the fifth lens are cemented lens groups.

[0008] Preferably, the axial distance between each lens satisfies the following relationship: the air gap between the first lens and the second lens is 4.0-5.0mm; the air gap between the second lens and the third lens is 0.1-0.5mm; the air gap between the third lens and the diaphragm is 2.0-2.5mm; the air gap between the diaphragm and the fourth lens is 0.5-1.0mm; the fourth lens and the fifth lens are cemented lens groups, and the air gap is 0mm; the air gap between the fifth lens and the sixth lens is 0.1-0.5mm; and the air gap between the sixth lens and the seventh lens is 0.1-1.0mm.

[0009] Preferably, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤7.5.

[0010] Preferably, the F number of the optical system is ≤1.5.

[0011] Preferably, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0012] Preferably, the rear side of the seventh lens is provided with a filter.

[0013] An imaging method of an 8M vehicle-mounted front-view main camera, which is performed according to the following steps: the optical system of the lens is imaged in sequence after the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens and the seventh lens.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] 1. The lens has an imaging angle of more than 140 degrees for an object, and has the advantages of super-high 8M imaging definition, large light aperture, low tolerance sensitivity, and good high-low temperature stability, etc., and can monitor the scene outside the vehicle more comprehensively;

[0016] 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;

[0017] 3. The all-glass structure has high stability and can adapt to harsh environments;

[0018] 4. The focusing surface displacement can be compensated well at high and low temperatures, and the system has complex environment adaptability;

[0019] 5. The axial color difference, sagittal color difference and high-order color difference are corrected, so that the imaging system can also have high imaging quality at a large angle.

[0020] The application will be further described in detail below in combination with the drawings and specific embodiments. DETAILED DESCRIPTION

[0021] Fig. 1 is the optical structure schematic diagram of embodiment 1 of the application;

[0022] Fig. 2 is the axial color difference diagram of the full working waveband of embodiment 1 of the application;

[0023] Fig. 3 is the sagittal color difference diagram of the full working waveband of embodiment 1 of the application;

[0024] Fig. 4 is the field curvature distortion diagram of the full working waveband of embodiment 1 of the application;

[0025] Fig. 5 is the optical structure schematic diagram of embodiment 2 of the application;

[0026] Fig. 6 is the axial color difference diagram of the full working waveband of embodiment 2 of the application;

[0027] Fig. 7 is the sagittal color difference diagram of the full working waveband of embodiment 2 of the application;

[0028] Fig. 8 is the field curvature distortion diagram of the full working waveband of embodiment 2 of the application;

[0029] In the figure: STO- light diaphragm; L1- first lens; L2- second lens; L3- third lens; L4- fourth lens; L5- fifth lens; L6- sixth lens; L7- seventh lens; L8- equivalent glass flat plate; L9- equivalent glass flat plate; IMA- imaging surface. DETAILED DESCRIPTION

[0030] The application will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0032] It is also important to note that the terms "including", "comprising", and / or "having" as used herein are specifically intended to be open-ended and also to mean including, comprising, and / or having other components, in addition to the listed components.

[0033] As shown in FIG. 1, the embodiment provides an 8M vehicle-mounted front-view main camera, and an optical system of the lens is composed of a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from left to right along a light incident path. Figs. 1-8 The first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a double-convex positive lens, the fourth lens is a double-convex positive lens, the fifth lens is a negative lens, and the sixth lens is a double-convex positive lens.

[0034] While achieving the visual perception and recognition function of the vehicle, 8MP imaging is achieved, which can replace the front-view wide-angle camera and the front-view narrow-angle camera, realize a single-lens front-view camera module, greatly reduce the cost, and improve the market popularity. By reasonably distributing the optical power, surface type, center thickness of each lens, and axial distance between each lens, etc., the total length of the lens and the radial size of each lens are reduced, and the lens group is miniaturized.

[0035] In the embodiment of the application, 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, the sixth lens and the seventh lens are f1, f2, f3, f4, f5, f6 and f7 respectively, wherein f1, f2, f3, f4, f5, f6 and f7 satisfy the following ratios: -2.5 < f1 / f < -1.5, -5.0 < f2 / f < -3.0, 2.0 < f3 / f < 2.5, 1.5 < f4 / f < 2.0, -1.5 < f5 / f < -1.0, 1.5 < f6 / f < 3.0, and -8.0 < f7 / f < 122.0.

[0036] In the embodiment of the present application, the first lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the second lens satisfies the relationship: 1.7≤N d ≤2.0, 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; the seventh lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; wherein N d is the refractive index, and V d is the Abbe constant.

[0037] In the embodiment of the present application, the lenses are made of glass material, and the fourth lens and the fifth lens are cemented lens groups.

[0038] In the embodiment of the present application, the axial distance between each lens satisfies the following relationship: the air gap between the first lens and the second lens is 4.0-5.0 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 2.0-2.5 mm; the air gap between the diaphragm and the fourth lens is 0.5-1.0 mm; the fourth lens and the fifth lens are cemented lens groups, and the air gap is 0 mm; the air gap between the fifth lens and the sixth lens is 0.1-0.5 mm; and the air gap between the sixth lens and the seventh lens is 0.1-1.0 mm. In the case of meeting the imaging requirements, reducing the distance between each lens is beneficial to the optical total length of the lens.

[0039] In the embodiment of the present application, the optical total length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤7.5.

[0040] In the embodiment of the present application, the F number of the optical system is ≤1.5.

[0041] In the embodiment of the present application, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0042] In the embodiment of the present application, the rear side of the seventh lens is provided with a filter.

[0043] An imaging method of an 8M vehicle-mounted forward-looking main camera, which is performed in the following steps: the optical system of the lens sequentially forms an image after the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens and the seventh lens.

[0044] Specific implementation process: first implementation:

[0045] The optical lens is sequentially provided with a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens from the object side to the image side. The first lens and the second lens are both glass spherical lenses with negative focal length, adjusting the large-angle light, and the second lens and the seventh lens are glass aspheric lenses, which have 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 8M, super wide angle, large aperture, day and night focus, low temperature drift design, and at the same time, the on-axis and off-axis aberrations are well corrected, and the imaging quality is good, as shown in Figs. 2-4 .

[0046] 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;

[0047] The second lens is a meniscus concave negative lens, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;

[0048] 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;

[0049] 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;

[0050] The fifth lens is a meniscus concave negative lens, the object side surface of which is a concave surface, and the image side surface of which is a convex surface;

[0051] 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;

[0052] The seventh lens is a meniscus concave positive lens, the object side surface of which is a convex surface, and the image side surface of which is a concave surface;

[0053] The technical indicators achieved by the optical system of the embodiment are as follows:

[0054] (1) focal length: 3.0≤EFFL≤4.0mm;

[0055] (2) aperture F≤1.5;

[0056] (3) field of view angle: 2w≥140°;

[0057] (4) working waveband: visible light waveband.

[0058] To achieve the above design parameters, the specific design of the optical system of the embodiment is shown in the following table:

[0059]

[0060]

[0061] The asphericity coefficients of each aspheric lens of the optical system of the embodiment are shown in the following table:

[0062]

[0063] The aspheric curve equation expression is:

[0064]

[0065] Wherein, Z is the sagittal height of the asphere at a height of h along the optical axis; c is the paraxial curvature of the asphere; k is the conic constant; α1, α2, α3, α4, α5, α6, α7, α8 are high-order coefficients.

[0066] The optical system of the embodiment, by reasonably allocating the focal power, surface shape, center thickness of each lens, and on-axis distance between lenses, etc., while meeting the 8M imaging performance requirements of the lens, reduces the total length of the lens and the radial size of each lens, and achieves the miniaturization of the lens group.

[0067] Second embodiment:

[0068] The optical lens is sequentially provided with a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens, and a seventh lens from the object side to the image side. The first lens and the second lens are both glass spherical lenses with negative focal power, which adjust the large-angle light, and the second lens, the third lens, the sixth lens, and the seventh lens are glass aspheric lenses, which have the effect of reducing the aberration of the optical system. The fourth lens and the fifth lens form an achromatic double cemented lens. Reasonable lens matching enables the optical system to achieve 8M, super wide angle, large aperture, day and night focus, low temperature drift design, and good correction of on-axis and off-axis aberrations, thereby achieving good imaging quality, as shown in Figs. 6-8 .

[0069] The first lens is a meniscus concave negative lens, whose object side surface is convex, and whose image side surface is concave.

[0070] The second lens is a meniscus concave negative lens, whose object side surface is concave, and whose image side surface is convex.

[0071] The third lens is a double-convex positive lens, whose object side surface is convex, and whose image side surface is convex.

[0072] The fourth lens is a biconvex positive lens, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;

[0073] The fifth lens is a biconcave negative lens, the object side surface of which is a concave surface, and the image side surface of which is a concave surface;

[0074] The sixth lens is a biconvex positive lens, the object side surface of which is a convex surface, and the image side surface of which is a convex surface;

[0075] The seventh 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;

[0076] The technical indexes realized by the optical system of the embodiment are as follows:

[0077] (5) focal length: 3.0≤EFFL≤4.0mm;

[0078] (6) aperture: F≤1.5;

[0079] (7) field of view: 2w≥140°;

[0080] (8) working waveband: visible light waveband.

[0081] To realize the design parameters mentioned above, the specific design adopted by the optical system of the embodiment is shown in the following table:

[0082]

[0083]

[0084] The asphericity coefficients of the aspheric lenses of the optical system of the embodiment are shown in the following table:

[0085]

[0086] The aspheric curve equation expression is:

[0087]

[0088] wherein, Z is the sagittal height of the aspheric surface at a position with a height of h along the optical axis from the vertex of the aspheric surface; c is the paraxial curvature of the aspheric surface; k is the conic constant; α1, α2, α3, α4, α5, α6, α7, α8 are high-order term coefficients.

[0089] The optical system of the embodiment realizes the miniaturization of the lens group by reasonably distributing the optical power, surface shape, central thickness of each lens, and axial distance between each lens, etc., while meeting the 8M imaging performance requirements of the lens.

[0090] The above merely describes preferred embodiments of the present application, but is not intended to limit the present application to other forms, and any person skilled in the art can make changes or modifications to the above disclosed technical contents into equivalent embodiments with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution content of the present application and according to the technical essence of the present application still belongs to the protection scope of the technical solution of the present application.

Claims

1. An 8M front-viewing primary vehicle camera, characterized by: The optical system of the main camera is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from left to right along the light path of light incidence; wherein the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a biconvex positive lens, the fourth lens is a biconvex positive lens, the fifth lens is a negative lens, and the sixth lens is a biconvex positive lens; the main camera has seven lenses with optical power; the focal length of the optical system is set as f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are f1, f2, f3, f4, f5, f6 and f7 respectively, wherein f1, f2, f3, f4, f5, f6 and f7 satisfy the following ratios: -2.5 < f1 / f < -1.5, -5.0 < f2 / f < -3.0, 2.0 < f3 / f < 2.5, 1.5 < f4 / f < 2.0, -1.5 < f5 / f < -1.0, 1.5 < f6 / f < 3.0, and -8.0 < f7 / f < 122.0; the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f ≤ 7.5; the F number of the optical system is ≤ 1.5; the image height H of the optical system and the focal length f of the optical system satisfy: H / f ≥ 1.

0.

2. The 8M front-viewing primary vehicle camera of claim 1, wherein: The first lens satisfies the relationship: 1.7 ≤ N d ≤ 2.0, V d ≤ 50.0; the second lens satisfies the relationship: 1.7 ≤ N d ≤ 2.0, 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; the seventh lens satisfies the relationship: 1.7 ≤ N d ≤ 2.0, V d ≤ 50.0; wherein N d is the refractive index, and V d is the Abbe number.

3. The 8M front view main camera for vehicle according to claim 1, characterized in that: All the lenses are made of glass material, and the fourth lens and the fifth lens form a cemented lens group.

4. The 8M front view main camera for vehicle according to claim 1, characterized in that: The on-axis distance between each lens satisfies the following relationship: the air gap between the first lens and the second lens is 4.0-5.0mm; the air gap between the second lens and the third lens is 0.1-0.5mm; the air gap between the third lens and the diaphragm is 2.0-2.5mm; the air gap between the diaphragm and the fourth lens is 0.5-1.0mm; the fourth lens and the fifth lens form a cemented lens group with an air gap of 0mm; the air gap between the fifth lens and the sixth lens is 0.1-0.5mm; and the air gap between the sixth lens and the seventh lens is 0.1-1.0mm.

5. The 8M front view main camera for vehicle according to claim 1, characterized in that: A filter is arranged on the rear side of the seventh lens.

6. An imaging method of the 8M vehicle-mounted forward-looking main camera head according to any one of claims 1 to 5, characterized by, The optical system of the main camera is imaged in sequence through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens and the seventh lens.

Images