An ultra-wide-angle 8m front-view main camera and an imaging method thereof

Abstract

The application relates to an ultra-wide-angle 8M front-view main camera and an imaging method thereof. The optical system of the camera has lenses with optical power along an incident light path, and the lenses are sequentially a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. A diaphragm is arranged between the third lens and the fourth lens. The fifth lens and the sixth lens are tightly connected to form a cemented lens group. The first lens is a meniscus concave negative lens, the second lens is a double-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-convex positive lens, the sixth lens is a double-concave negative lens, and the seventh lens is a double-convex positive lens. The first, third, fourth, fifth and sixth lenses are glass spherical lenses, and the second and seventh lenses are glass aspherical lenses. The imaging angle of the object is greater than 170 degrees, and the 8M imaging definition is super high, so that the vehicle exterior scene can be monitored more comprehensively.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of lenses, in particular to an ultra-wide-angle 8M front-view main camera and an imaging method thereof. BACKGROUND

[0002] Vehicle automatic driving includes perception, judgment and execution, and the perception is the source of the whole process and an important module of the automatic driving system. In the process of vehicle driving, the perception system can collect the information of the surrounding environment in real time through a camera module, which is equivalent to the "eyes" of the automatic driving vehicle and can help the vehicle realize the observation ability similar to that of a human driver. The front-view camera installed on the front windshield is used to realize the visual perception and recognition function of driving, and can be divided into a front-view main camera, a front-view narrow-angle camera and a front-view wide-angle camera according to the function, but the adoption of the three cameras greatly increases the cost of the whole camera module, which is not conducive to the popularization of the market. The function of the front-view wide-angle camera is mainly to recognize objects at a relatively short distance, and it is mainly used in urban road working conditions, low-speed driving and other scenes, and the field of view angle is 120 DEG ~ 150 DEG, and the detection distance is about 50 m. Therefore, if the ultra-wide-angle 8MP lens is adopted on a large scale, the camera can be unnecessary, so as to reduce the cost and improve the market popularization. SUMMARY

[0003] Therefore, the purpose of the application is to provide an ultra-wide-angle 8M front-view main camera and an imaging method thereof, which have a large imaging angle, meet the 8M ultra-wide-angle imaging performance requirements of the lens and have a small size.

[0004] The application adopts the following scheme: an ultra-wide-angle 8M front-view main camera, the optical system of the camera has lenses with optical power along the incident light path in sequence, and the lenses are a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, a diaphragm is arranged between the third lens and the fourth lens, and the fifth lens and the sixth lens are tightly connected to form a cemented lens group; the first lens is a meniscus concave negative lens, the second lens is a double-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-convex positive lens, the sixth lens is a double-concave negative lens, and the seventh lens is a double-convex positive lens; the first, third, fourth, fifth and sixth lenses are glass spherical lenses, and the second and seventh lenses are glass aspherical lenses.

[0005] Further, 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: -2.0 < f1 / f < -1.0, -3.0 < f2 / f < -2.0, 2.0 < f3 / f < 3.0, 2.0 < f4 / f < 3.0, 1.0 < f5 / f < 2.0, -2.0 < f6 / f < -1.0, and 2.0 < f7 / f < 3.0.

[0006] Further, the first lens satisfies the relationship: 2.0 ≤ Nd ≤ 2.3 and Vd ≤ 50.0, the second lens satisfies the relationship: 1.5 ≤ Nd ≤ 1.8 and Vd ≥ 50.0, the third lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≤ 50.0, the fourth lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≤ 50.0, the fifth lens satisfies the relationship: 1.5 ≤ Nd ≤ 1.8 and Vd ≥ 50.0, the sixth lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≤ 50.0, and the seventh lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≥ 50.0; wherein Nd is the refractive index and Vd is the Abbe number.

[0007] Further, the air gap between the first lens and the second lens is 4.1-4.5mm, the air gap between the second lens and the third lens is 0.5-1.0mm, the air gap between the third lens and the diaphragm is 1.5-2.0mm, the air gap between the fourth lens and the fifth lens is 0.1-0.5mm, and the air gap between the sixth lens and the seventh lens is 1.0-1.5mm.

[0008] Further, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f ≤ 8.0.

[0009] Further, the F number of the optical system is ≤1.6.

[0010] Further, the image height H of the optical system and the focal length f of the optical system satisfy: H / f ≥ 1.0.

[0011] Further, the rear side of the seventh lens is provided with a filter.

[0012] Another technical solution of the present application is an imaging method of the ultra-wide-angle 8M front-view main camera as described above, and light rays are sequentially imaged after passing through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the filter.

[0013] Compared with the prior art, the present application has the following beneficial effects:

[0014] 1. The lens has an imaging angle of more than 170 degrees for an object, and has the advantages of super-high 8M imaging definition, large light aperture, low tolerance sensitivity, good high and low temperature stability, etc. Meanwhile, the lens can monitor the scene outside the vehicle more comprehensively.

[0015] 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.

[0016] 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 smaller lens outer diameter and shorter optical total length, and ensures the miniaturization of the lens.

[0017] 4. The lens can make good compensation for the displacement of the focusing surface at high and low temperatures, and has adaptability to complex environments.

[0018] 5. The lens corrects axial color difference, sagittal color difference and high-order color difference, and ensures that the imaging system has high imaging quality at a large angle.

[0019] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with specific examples and related drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] Fig. 1 is a schematic diagram of the optical system structure of the camera of the present application;

[0021] Fig. 2 is an axial color difference graph of the camera of the present application in the full working waveband;

[0022] Fig. 3 is a sagittal color difference graph of the camera of the present application in the full working waveband;

[0023] Fig. 4 is a field curvature distortion graph of the camera of the present application in the full working waveband;

[0024] Explanation of reference numerals in the drawings: STO- stop; 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

[0025] It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0026] It is to be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0027] As shown in Figs. 1-4 An ultra-wide-angle 8M front-view main camera, the optical system of the camera has lenses with optical power along the incident light path in order: first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, and seventh lens, a diaphragm is arranged between the third lens and the fourth lens, wherein the fifth lens and the sixth lens are in close contact to 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 is convex, and the image side surface is concave; the second lens is a double-concave negative lens, the object side surface is concave, and the image side surface is concave; the third lens is a double-convex positive lens, the object side surface is convex, and the image side surface is convex; the fourth lens is a double-convex positive lens, the object side surface is convex, and the image side surface is convex; the fifth lens is a double-convex positive lens, the object side surface is convex, and the image side surface is convex; the sixth lens is a double-concave negative lens, the object side surface is concave, and the image side surface is concave; the seventh lens is a double-convex positive lens, the object side surface is convex, and the image side surface is convex; the lenses are made of glass material, the first, third, fourth, fifth, and sixth lenses are glass spherical lenses, and the second and seventh lenses are glass aspherical lenses.

[0028] The first lens and the second lens have negative optical power and can adjust large-angle light, and the glass aspherical surface therein simultaneously has the effect of reducing the distortion of the optical system. The fifth lens and the sixth lens form an achromatic double-cemented lens. Reasonable lens matching enables the optical system to achieve 8M, ultra-wide-angle, large-aperture, day-and-night focus, low-temperature drift design, and good correction of on-axis and off-axis aberrations, and has good imaging quality, as shown in Figs. 2-4 .

[0029] In the present embodiment, 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: -2.0 < f1 / f < -1.0, -3.0 < f2 / f < -2.0, 2.0 < f3 / f < 3.0, 2.0 < f4 / f < 3.0, 1.0 < f5 / f < 2.0, -2.0 < f6 / f < -1.0, and 2.0 < f7 / f < 3.0.

[0030] In the embodiment, the first lens satisfies the relationship: 2.0≤Nd≤2.3, Vd≤50.0; the second lens satisfies the relationship: 1.5≤Nd≤1.8, Vd≥50.0; the third lens satisfies the relationship: 1.7≤Nd≤2.0, Vd≤50.0; the fourth lens satisfies the relationship: 1.7≤Nd≤2.0, Vd≤50.0; the fifth lens satisfies the relationship: 1.5≤Nd≤1.8, Vd≥50.0; the sixth lens satisfies the relationship: 1.7≤Nd≤2.0, Vd≤50.0; the seventh lens satisfies the relationship: 1.7≤Nd≤2.0, Vd≥50.0; wherein Nd is the refractive index, and Vd is the Abbe number.

[0031] In the embodiment, the air gap between the first lens and the second lens is 4.1-4.5 mm; the air gap between the second lens and the third lens is 0.5-1.0 mm; the air gap between the third lens and the diaphragm is 1.5-2.0 mm; the diaphragm is located on the fourth lens S1; the air gap between the fourth lens and the fifth lens is 0.1-0.5 mm; the fifth lens and the sixth lens are cemented lenses, and the air gap is 0 mm; the air gap between the sixth lens and the seventh lens is 1.0-1.5 mm.

[0032] In the embodiment, the aspherical surface curve equation expression of the second lens and the seventh lens is:

[0033]

[0034] wherein Z is the sagittal height of the aspherical surface at a position with 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; 、 、 、 、 、 、 、 are high-order coefficients.

[0035] The aspherical surface coefficients of each aspherical lens are as follows:

[0036]

[0037] In the embodiment, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤8.0.

[0038] In the embodiment, the F number of the optical system is ≤1.6.

[0039] In the embodiment, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0040] In the embodiment, the rear side of the seventh lens is provided with a filter.

[0041] Technical indexes realized by the optical system in the embodiment are as follows:

[0042] (1) focal length: 3.0≤EFFL≤4.0mm;

[0043] (2) aperture F≤1.6;

[0044] (3) field of view angle: 2w≥170°;

[0045] (4) working waveband: visible light waveband.

[0046] To realize the above design parameters, the specific parameter design of the optical system in the embodiment is shown in the following table:

[0047]

[0048] The optical system in the embodiment realizes the miniaturization of the lens group by reasonably distributing the optical power, surface shape, central thickness of each lens and the axial distance between each lens, etc., while meeting the 8M super wide-angle imaging performance requirements of the lens. At the same time, the total length of the lens and the radial size of each lens are reduced. The 8MP imaging is realized while realizing the visual perception and recognition function of the vehicle, so as to replace the front wide-angle camera and the front narrow-angle camera, realize the single lens group into the front camera module, greatly reduce the cost and improve the market popularity.

[0049] An imaging method of the above-mentioned super wide-angle 8M front view main camera, light rays are sequentially imaged after the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the filter.

[0050] Any technical solution disclosed in the present application, unless otherwise stated, if it discloses a numerical range, the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is only one of the many implementable numerical values with more obvious technical effects or representative values. Because there are too many values, it is impossible to enumerate them all, so the present application discloses some values to illustrate the technical solutions of the present application, and the above-mentioned enumerated values should not constitute a limitation on the protection scope of the present application.

[0051] If the present application discloses or involves mutually fixedly connected parts or structural members, unless otherwise stated, the fixed connection can be understood as: detachably fixedly connected (for example, connected using bolts or screws), and can also be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the mutually fixed connection can also be replaced by an integral structure (for example, integrally formed by using a casting process) (obviously, an integral forming process cannot be used).

[0052] In addition, the terms used to represent the positional relationship or shape in any of the technical solutions disclosed in the present application include states or shapes similar, similar or close to them, unless otherwise stated.

[0053] Any component provided by the present application can be assembled from multiple individual components, or can be a single component manufactured by an integral forming process.

[0054] The above 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 disclosed technical content to equivalent embodiments. However, any simple modification, equivalent change and modification made on the basis of the technical essence of the present application without departing from the technical solution content of the present application still belongs to the protection scope of the present application.

Claims

1. An ultra-wide 8M front-facing main camera, characterized in that: The optical system of the camera has 7 lenses with optical power, which are sequentially arranged along the incident light path as a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, and a diaphragm is arranged between the third lens and the fourth lens, wherein the fifth lens and the sixth lens are tightly arranged to form a cemented lens group; the first lens is a meniscus concave negative lens, the second lens is a double-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-convex positive lens, the sixth lens is a double-concave negative lens, and the seventh lens is a double-convex positive lens; the first, third, fourth, fifth and sixth lenses are glass spherical lenses, and the second and seventh lenses are glass aspherical lenses; the focal length of the optical system is f, and the focal lengths of the first, second, third, fourth, fifth, sixth and seventh lenses are f1, f2, f3, f4, f5, f6 and f7 respectively, wherein f1, f2, f3, f4, f5, f6 and f7 and f satisfy the following ratios: -2.0 < f1 / f < -1.0, -3.0 < f2 / f < -2.0, 2.0 < f3 / f < 3.0, 2.0 < f4 / f < 3.0, 1.0 < f5 / f < 2.0, -2.0 < f6 / f < -1.0, and 2.0 < f7 / f < 3.0; the first lens satisfies the relationship: 2.0 ≤ Nd ≤ 2.3 and Vd ≤ 50.0; the second lens satisfies the relationship: 1.5 ≤ Nd ≤ 1.8 and Vd ≥ 50.0; the third lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≤ 50.0; the fourth lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≤ 50.0; the fifth lens satisfies the relationship: 1.5 ≤ Nd ≤ 1.8 and Vd ≥ 50.0; the sixth lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≤ 50.0; and the seventh lens satisfies the relationship: 1.7 ≤ Nd ≤ 2.0 and Vd ≥ 50.0; wherein Nd is the refractive index, and Vd is the Abbe number; the optical total length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f ≤ 8.0; 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 8M front-facing primary camera of claim 1, wherein: The air gap between the first lens and the second lens is 4.1-4.5 mm; the air gap between the second lens and the third lens is 0.5-1.0 mm; the air gap between the third lens and the diaphragm is 1.5-2.0 mm; the air gap between the fourth lens and the fifth lens is 0.1-0.5 mm; and the air gap between the sixth lens and the seventh lens is 1.0-1.5 mm. 3.The ultra-wide 8M front-facing primary camera of claim 1, wherein: The F number of the optical system is ≤1.

6.

4. The ultra-wide 8M front-facing primary camera of claim 1, wherein: The rear side of the seventh lens is provided with a filter.

5. The imaging method of the ultra-wide-angle 8M front-view primary camera according to claim 4, characterized in that: Light rays are sequentially imaged through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the filter.

Images