Low total length 8m front-view main camera and working method thereof

Abstract

The application relates to a low-total-length 8M front-view main camera and a working method thereof, wherein the optical system of the low-total-length 8M front-view main camera is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens arranged in sequence from left to right along the light incident path. The lenses are made of plastic and glass materials, the first, second, fourth, sixth and seventh lenses are glass spherical lenses, the third and fifth lenses are plastic aspherical lenses, and the sixth and seventh lenses are cemented lens groups. By reasonably distributing the optical power, 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 low-total-length 8M super-wide-angle imaging performance of the 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 application relates to the technical field of lenses, in particular to a low-total-length 8M front-view main camera and a working method thereof. BACKGROUND

[0002] With the continuous development of the automobile industry, front-view optical lenses are widely applied to intelligent vehicle information systems including automatic driving technology, collision warning, lane departure warning and driving recording, for collecting and identifying road, pedestrian, vehicle and obstacle information in front, so as to improve the comfort and safety of driving.

[0003] In order to realize a single lens module, the front-view optical lens needs to meet the advantages of 8M high resolution, large field of view, good environmental adaptability and the like, while there are also disadvantages such as too many lenses and too long optical total length, which is not conducive to the miniaturization of the overall system.

[0004] At present, the Chinese patent "Large field of view, high pixel optical system and mobile phone camera module adopting the optical system" (publication number CN111045196A) is retrieved, which comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged in sequence from the object side to the image side, the first lens is a convex lens, the second lens is a concave lens, the third lens, the fourth lens and the fifth lens are reverse curved surface lenses, due to the special design of the aspheric profile shape of the optical system and the reasonable setting of the refractive index of each piece of material, the design requirements of the large image field and high pixel of the optical system are met, the overall brightness of the optical system is increased, and the production cost is reduced, although the optical system of the mobile phone camera module of the patent adopts a deformed elastic body embedded positioning structure to ensure the stability of the shooting resolution and improve the assembly yield of the camera module; but it cannot realize the visual perception and recognition function of driving at the same time, realize low-cost 8MP imaging, replace the front-view wide-angle camera and the front-view narrow-angle camera, realize the single lens composition of the front-view camera module, and greatly reduce the cost to improve the market popularity. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a low-total-length 8M front-view main camera and a working method thereof, which can realize the visual perception and recognition function of driving at the same time, realize low-cost 8MP imaging, replace the front-view wide-angle camera and the front-view narrow-angle camera, realize the single lens composition of the front-view camera module, greatly reduce the cost and improve the market popularity.

[0006] In order to solve the above technical problems, the technical scheme of the present application is:

[0007] An 8M low total length front-facing main camera, characterized in that the optical system of the main camera is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens in sequence from left to right along the optical path; 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 biconvex 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 biconvex 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 meniscus convex positive lens, the object side surface of which is a concave surface and the image side surface of which is a convex surface; the sixth 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; the seventh 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; the lenses are made of plastic and glass materials, the first, second, fourth, sixth and seventh lenses are glass spherical lenses, and the third and fifth lenses are plastic aspherical lenses, wherein the image side surface of the sixth lens and the object side surface of the seventh lens are glued to form a glued lens group.

[0008] 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, 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: -3.0 < f1 / f < -2.0, -3.0 < f2 / f < -2.0, 8.0 < f3 / f < 9.0, 2.0 < f4 / f < 3.0, 3.0 < f5 / f < 4.0, -2.0 < f6 / f < -1.0, and 1.0 < f7 / f < 2.0.

[0009] Preferably, the first lens satisfies the relationship: 2.0 ≤ N d ≤ 2.3, 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: 1.5 ≤ N d ≤ 1.8, V d ≤ 50.0; the fourth lens satisfies the relationship: 1.7 ≤ N d ≤ 2.0, V d ≤ 50.0; the fifth lens satisfies the relationship: 1.5 ≤ N d ≤ 1.8, V d ≥ 50.0; the sixth lens satisfies the relationship: 2.0 ≤ N d ≤ 2.3, V d ≤ 50.0; and the seventh lens satisfies the relationship: 1.7 ≤ N d ≤ 2.0, V d ≤ 50.0; wherein N dV is the refractive index, and d V is the Abbe number.

[0010] Preferably, the distance between each lens on the optical axis satisfies the following relationship: the air gap between the first lens and the second lens is 2.0-2.5 mm; the air gap between the second lens and the third lens is 1.0-1.5 mm; the air gap between the third lens and the fourth lens is 0.5-1.0 mm; the air gap between the fourth lens and the diaphragm is 0.1-0.5 mm; the air gap between the diaphragm and the fifth lens is 0.5-1.0 mm; the air gap between the fifth lens and the sixth lens is 0.1-0.5 mm; and the sixth lens and the seventh lens are a cemented lens with an air gap of 0 mm.

[0011] Preferably, the third lens and the fifth lens are both aspherical lenses, and the aspherical curve equation is expressed as:

[0012]

[0013] wherein Z is the sagittal height 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; and α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order coefficients.

[0014] Preferably, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤10.0.

[0015] Preferably, the F number of the optical system is ≤1.6.

[0016] Preferably, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0017] Preferably, a filter is arranged on the rear side of the seventh lens.

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

[0019] 1. The lens has an imaging angle of more than 195 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. Meanwhile, the lens can more comprehensively monitor the scene outside the vehicle.

[0020] 2. By reasonably matching the optical lenses, the system structure is compact and reasonable, the total length is 17 mm, the assembly is easy, the tolerance sensitivity is low, and the system is more suitable for large-scale high-yield production.

[0021] 3. The glass-plastic hybrid structure is adopted, which has low manufacturing cost and light weight, and is beneficial to the manufacturing and installation of the module.

[0022] 4. It can make better compensation for the focal plane displacement at high and low temperatures, and has adaptability to complex environment;

[0023] 5. The axial chromatic aberration, sagittal chromatic aberration and high-order chromatic aberration are corrected, and the imaging system can have higher imaging quality at a large angle.

[0024] 6. The advantages of the aspherical lens in correcting aberration are fully utilized, the high-definition imaging is met, the lens has smaller outer diameter and shorter optical total length, and the miniaturization of the lens is ensured.

[0025] The application will be further described in detail below in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the optical structure schematic diagram of the application;

[0027] Figure 2 is the axial chromatic aberration diagram of the full working waveband of the application;

[0028] Figure 3 is the sagittal chromatic aberration diagram of the full working waveband of the application;

[0029] Figure 4 is the field curvature distortion diagram of the full working waveband of the application;

[0030] In the figure: STO-optical 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

[0031] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0032] As Figure 1As shown, a low total length 8M front view main camera, the optical system of the main camera is incident from left to right along the optical path in turn by first lens L1, second lens L2, third lens L3, fourth lens L4, diaphragm, fifth lens L5, sixth lens L6 and seventh lens L7; the first lens is a meniscus concave negative lens, the object side is convex, and the image side is concave; the second lens is a meniscus concave negative lens, the object side is convex, and the image side is concave; the third lens is a double convex positive lens, the object side is convex, and the image side is convex; the fourth lens is a double convex positive lens, the object side is convex, and the image side is convex; the fifth lens is a meniscus convex positive lens, the object side is concave, and the image side is convex; the sixth lens is a double concave negative lens, the object side is concave, and the image side is concave; the seventh lens is a double convex positive lens, the object side is convex, and the image side is convex; the lenses are made of plastic and glass materials, the first, second, fourth, sixth and seventh lenses are glass spherical lenses, and the third and fifth lenses are plastic aspherical lenses, wherein the image side of the sixth lens and the object side of the seventh lens are glued to form a glued lens group.

[0033] The first lens and the second lens have negative focal power, which can adjust the large-angle light; the third lens is a plastic aspherical surface, which has the effect of reducing the distortion of the optical system; the sixth lens and the seventh lens form an achromatic double-glued lens; reasonable lens matching makes the optical system realize low cost, low total length, 8M, super wide angle, large aperture, day and night focus, low temperature drift design, and good correction of on-axis and off-axis aberrations, with good imaging quality. Figures 2 to 4 As shown, the technical indicators realized by the optical system of the embodiment are as follows:

[0034] (1) focal length: 1.0≤EFFL≤2.0mm;

[0035] (2) aperture F≤1.6;

[0036] (3) field of view angle: 2w≥195°;

[0037] (4) working waveband: visible light waveband.

[0038] To realize the above design parameters, the specific design of the optical system of the embodiment is shown in the following table:

[0039]

[0040] The aspherical surface coefficients of each aspherical surface lens of the optical system of the embodiment are as follows:

[0041]

[0042] The optical system of the embodiment can meet the low total length 8M super wide-angle imaging performance requirement, reduce the total length of the lens and the radial size of each lens, and achieve miniaturization of the lens group by reasonably allocating the focal power, surface shape, central thickness of each lens, and axial distance between each lens.

[0043] The above description is only the 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 of the above embodiments made according to the technical essence of the present application without departing from the technical solution of the present application still falls within the protection scope of the present application.

Claims

1. A low total length 8M front-facing primary camera, characterized by: The optical system of the main camera is composed of a first lens, a second lens, a third lens, a fourth lens, a diaphragm, a fifth lens, a sixth lens and a seventh lens in sequence from left to right along the light path; the first lens is a meniscus concave negative lens, the object side surface of which is a convex surface and the image side surface 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 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 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 is a convex surface; the fifth lens is a meniscus convex positive lens, the object side surface of which is a concave surface and the image side surface is a convex surface; the sixth lens is a double-concave negative lens, the object side surface of which is a concave surface and the image side surface is a concave surface; the seventh lens is a double-convex positive lens, the object side surface of which is a convex surface and the image side surface is a convex surface; the lenses are made of plastic and glass materials, the first, second, fourth, sixth and seventh lenses are glass spherical lenses, the third and fifth lenses are plastic aspherical lenses, and the image side surface of the sixth lens and the object side surface of the seventh lens are glued to form a glued lens group; the specific parameters of the optical system are shown in the following table: 。 2. The working method of the low total length 8M front-view main camera according to claim 1, characterized in that: When the light is incident, it enters the first lens, the second lens, the third lens, the fourth lens, the diaphragm, the fifth lens, the sixth lens, the seventh lens and the equivalent glass flat plate in sequence along the light path, and then is imaged on the IMA imaging surface.

Images