Six-piece 8m front-view main camera and imaging method

Abstract

The application relates to a six-piece 8M front-view main camera and an imaging method. The optical system of the camera 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 left to right along the light path of light incidence. The lenses are all made of glass material, the first, second, third, fourth and fifth lenses are glass spherical surface lenses, and the sixth lens is a glass aspherical surface lens. The fourth and fifth lenses are a cemented lens group. By reasonably distributing the focal length, surface type, central 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 while the 8M imaging performance of the six-piece lens meets the requirements of the front-view wide-angle camera and the front-view narrow-angle camera, and the lens group is miniaturized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lens, in particular to a six-piece 8M front-view main camera and an imaging method. BACKGROUND

[0002] With the development of automobile safety technology, the vehicle-mounted vision system gradually becomes an important part of the automobile electronic system. In order to achieve the goal of safe driving, the vehicle-mounted vision system with vehicle-mounted camera module as the core is installed in different parts of the automobile. The front-view camera is mainly installed on the front windshield, which is used to realize the visual perception and recognition function of driving. According to the function, it can be divided into front-view main camera, front-view narrow-angle camera and front-view wide-angle camera. The function of the front-view wide-angle camera is mainly to recognize objects at a relatively close distance, which is mainly used in urban road working conditions, low-speed driving and other scenes. Its field of view is 120°-150°, and the detection distance is about 50m. Therefore, if 8MP lenses are widely used in vehicles, the camera can be replaced, which reduces the cost of the front-view module and is assisted by a lower number of lenses, which is conducive to the further promotion and popularization of the market. SUMMARY

[0003] In view of the deficiencies of the prior art, the technical problem to be solved by the present application is to provide a six-piece 8M front-view main camera, which realizes the visual perception and recognition function of driving while realizing 8MP imaging. In this way, the front-view wide-angle camera and the front-view narrow-angle camera can be replaced, a single lens can be used to form a front-view camera module, and the cost can be greatly reduced to improve the market popularity.

[0004] In order to solve the above technical problems, the technical scheme of the present application is as follows: a six-piece 8M front-view main camera, 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 from left to right along the light incident path; without considering the reverse bending caused by the aspherical coefficient, 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 double-concave negative lens; the sixth lens is a meniscus convex positive lens; 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 aspherical lens, wherein the fourth lens and the fifth lens are cemented lens groups.

[0005] Preferably, the object side of the first lens is convex, and the image side is concave; the object side of the second lens is convex, and the image side is concave; the object side of the third lens is convex, and the image side is convex; the object side of the fourth lens is convex, and the image side is convex; the object side of the fifth lens is concave, and the image side is concave; the object side of the sixth lens is concave, and the image side is convex.

[0006] 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: -6.0 < f1 / f < -5.0, -3.0 < f2 / f < -2.0, 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.

[0007] 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; the third lens satisfies the relationship: 2.0 ≤ N d ≤ 2.3, 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: 1.7 ≤ N d ≤ 2.01, and V d ≤ 50.0; and the sixth lens satisfies the relationship: 1.7 ≤ N d ≤ 2.0, and V d ≤ 50.0; wherein N d is the refractive index, and V d is the Abbe number.

[0008] Preferably, 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 third lens is 4.5-5.0 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 0.1-0.5 mm; the fourth lens and the fifth lens are cemented together, 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.

[0009] Preferably, the sixth lens is a non-spherical lens; and the non-spherical curve equation is expressed as:

[0010]

[0011] wherein Z is the sagittal height of the non-spherical lens at a height of r along the optical axis; c is the paraxial curvature of the non-spherical lens; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7 and α8 are high-order coefficients.

[0012] Preferably, the optical total length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤15.0.

[0013] Preferably, the F number of the optical system is ≤1.8.

[0014] Preferably, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0015] Preferably, the stop of the optical system is located between the third lens and the fourth lens, and the image side of the sixth lens is provided with a filter.

[0016] An imaging method of a six-piece 8M front-view main camera, which is performed according to the following steps: light rays are sequentially imaged on an imaging surface after passing through a first lens, a second lens, a third lens, a stop, a fourth lens, a fifth lens and a sixth lens from left to right.

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

[0018] 1. The lens has an imaging angle of more than 178 degrees for an object, and has the advantages of super-high 8M imaging clarity, large light aperture, low tolerance sensitivity and good high-low temperature stability, etc., and can more comprehensively monitor the scene outside the vehicle.

[0019] 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.

[0020] 3. The all-glass structure has high stability, can adapt to harsh environments, fully utilizes the advantages of aspheric lenses in correcting aberrations, meets the requirements of high-definition imaging, has a smaller lens outer diameter and shorter optical total length, and ensures the miniaturization of the lens.

[0021] 4. The lens can make good compensation for the displacement of the focal plane at high and low temperatures, and has adaptability to complex environments.

[0022] 5. The lens corrects axial chromatic aberration, sagittal chromatic aberration and high-order chromatic aberration, and ensures that the imaging system also has 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] Fig. 1 The optical structure of the embodiment of the present application is shown in the figure;

[0025] Fig. 2 The full working waveband axial chromatic aberration diagram of the embodiment of the present application is shown in the figure;

[0026] Fig. 3 The full working waveband field curvature distortion chart of the embodiment of the present application;

[0027] Fig. 4 The full working waveband field curvature distortion chart of the embodiment of the present application;

[0028] In the figure: STO - diaphragm; 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 plane. DETAILED DESCRIPTION

[0029] In order to make the above features and advantages of the present application more obvious and easy to understand, the following specific examples are described in detail below, and the drawings are as follows.

[0030] As shown in Figs. 1-4 , a six-piece 8M front-view main camera lens, the optical lens is sequentially provided with a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens from the object side to the image side, and the sixth lens is sequentially provided with a filter L7 and a chip protection glass (CG) L8 to the image side.

[0031] In the embodiment of the present application, the diaphragm of the optical system is located between the third lens and the fourth lens, and the sixth lens is provided with a filter on the image side.

[0032] In the embodiment of the present application, the first lens and the second lens are both glass lenses with negative focal length, which can adjust the large-angle light, and the glass aspheric surface in it 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 realize six-piece, 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 to 4 The technical indicators realized by the optical system of the embodiment are as follows:

[0033] (1) focal length: 1.0≤EFFL≤2.0mm;

[0034] (2) aperture F≤1.8;

[0035] (3) field of view angle: 2w≥178°;

[0036] (4) working waveband: visible light waveband.

[0037] In order to realize the above design parameters, the specific design of the optical system of the embodiment is as follows:

[0038]

[0039]

[0040] The aspheric coefficients of the aspheric lenses of the optical system of the present embodiment are as follows:

[0041]

[0042] The optical system of the present embodiment, by reasonably allocating the focal power of each lens, the surface shape, the central thickness of each lens, and the on-axis distance between each lens, etc., while meeting the 8M imaging performance requirements of the six-piece lens, reduces the total length of the lens and the radial size of each lens, and achieves miniaturization of the lens set.

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

Claims

1. A six-piece 8M front-facing primary camera comprising an optical system, 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 from left to right along the light path of the incident light; without considering the reverse bending caused by the aspherical surface coefficient, 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 double-concave negative lens; and the sixth lens is a meniscus convex positive lens; 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 aspherical lens, wherein the fourth lens and the fifth lens are cemented lens groups. The object side of the first lens is convex, and the image side is concave; the object side of the second lens is convex, and the image side is concave; the object side of the third lens is convex, and the image side is convex; the object side of the fourth lens is convex, and the image side is convex; the object side of the fifth lens is concave, and the image side is concave; and the object side of the sixth lens is concave, and the image side is convex. The air gap between the first lens and the second lens is 2.875 mm; the air gap between the second lens and the third lens is 4.708 mm; the air gap between the third lens and the diaphragm is 0.100 mm; the air gap between the diaphragm and the fourth lens is 0.1 mm; the fourth lens and the fifth lens are cemented pieces, and the air gap is 0 mm; and the air gap between the fifth lens and the sixth lens is 0.455 mm.

2. The six-piece 8M front-facing primary camera of claim 1, wherein: 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 and f satisfy the following ratios: -6.0 < f1 / f < -5.0, -3.0 < f2 / f < -2.0, 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.

3. The six-piece 8M front-facing primary camera of claim 1, wherein: The first lens satisfies the relation: N d = 1.84, V d = 40.47; the second lens satisfies the relation: N d = 1.79, V d = 47.97; the third lens satisfies the relation: N d = 2.00, V d = 25.43; the fourth lens satisfies the relation: N d = 1.59, V d = 68.62; the fifth lens satisfies the relation: N d = 1.95, V d = 17.94; the sixth lens satisfies the relation: N d = 1.77, V d = 49.59; wherein N d is the refractive index and V d is the Abbe number.

4. The six-piece 8M front-facing primary camera of claim 1, wherein: The sixth lens is an aspherical lens; and the aspherical curve equation expression is as follows: wherein Z is the sagittal height of the aspherical surface at a height of r along the optical axis; c is the paraxial curvature of the aspherical surface; k is the conic constant; and α1, α2, α3, α4, α5, α6, α7 and α8 are high-order coefficients.

5. The six-piece 8M front-facing primary camera of claim 1, wherein: The total optical length TTL of the optical system and the focal length f of the optical system satisfy TTL / f ≤ 15.

0.

6. The six-piece 8M front-facing primary camera of claim 1, wherein: The F number of the optical system is ≤1.

8.

7. The six-piece 8M front-facing primary camera of claim 1, wherein: The image height H of the optical system and the focal length f of the optical system satisfy H / f ≥ 1.

0.

8. An imaging method applied to the six-piece 8M front-view primary camera of claim 1, characterized in that, The following steps are performed: the light passes through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens and the sixth lens in sequence from left to right, and then is imaged on the imaging plane.

Images