A six-piece 8M front-view optical system

Abstract

The utility model relates to a six-piece 8M front-view optical system, wherein the optical lens is provided with a first lens, an aperture, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in sequence from the object side to the image side. The lenses are made of glass material, the first, second, third, fifth and sixth lenses are glass spherical lenses, the fourth lens is a glass aspherical lens, wherein the second lens and the third lens, the fifth lens and the sixth lens are a cemented lens group. By reasonably allocating the optical power, surface shape, center thickness of each lens and axial distance between each lens, etc. of each lens, while meeting the imaging performance of the six-piece lens 8M to replace the requirements of the front-view wide-angle camera and the front-view narrow-angle camera, the total length of the lens and the radial size of each lens are reduced, so as to achieve miniaturization of the lens group.

Description

Technical Field

[0001] The utility model relates to the technical field of lenses, in particular to a six-piece 8M front-view optical system. Background Art

[0002] There are two main functions of the vehicle-mounted front-view camera system: one is to record the driving trajectory and serve as one of the important bases for determining liability after a traffic accident occurs; the other is to assist driving, which can prevent the car from deviating from the lane and avoiding collisions with pedestrians on the road during driving, thereby effectively reducing the occurrence of traffic accidents. Therefore, the vehicle-mounted front-view camera system is an important hardware terminal in the advanced driver assistance system. The front-view camera can be divided into the front-view main camera, the front-view narrow-angle camera and the front-view wide-angle camera according to the function. Among them, the front-view wide-angle camera is mainly used to identify objects at a close distance. It is mainly used in scenes such as urban road conditions and low-speed driving. Its field of view is 120°~150° and the detection distance is about 50m. Therefore, if the 8MP lens is installed on a large scale, the camera can be omitted, which reduces the cost of the front-view module. At this time, if it is supplemented with a lower number of lenses, it is conducive to further market promotion and popularization. Utility Model Content

[0003] In view of the deficiencies in the prior art, the technical problem to be solved by the utility model is to provide a six-piece 8M front-view optical system, which can realize 8MP imaging while realizing the visual perception and recognition functions of driving, thereby replacing the front-view wide-angle camera and the front-view narrow-angle camera, and realizing a single-lens front-view camera module, thereby greatly reducing costs and increasing market popularity.

[0004] In order to solve the above technical problems, the technical solution of the utility model is: a six-piece 8M front-view optical system, the optical system of the lens is composed of a first lens, a stop, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence from left to right along the incident light path of the light, without considering the backcurvature caused by the aspheric coefficient, the first lens is a meniscus concave negative lens, the object side surface of which is convex, and the image side surface is concave; the second lens is a double convex positive lens, the object side surface of which is convex, and the image side surface is convex; the third lens is A double concave negative lens, whose object side surface is concave and whose image side surface is concave; the fourth lens is a meniscus convex positive lens, whose object side surface is concave and whose image side surface is convex; the fifth lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the sixth lens is a meniscus concave negative lens, whose object side surface is concave and whose image side surface is convex; the first lens, the second lens, the third lens, the fifth lens and the sixth lens are glass spherical lenses, and the fourth lens is a glass aspherical lens, wherein the second lens and the third lens, and the fifth lens and the sixth lens are a cemented lens group.

[0005] 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 ratio with f: -2.0 <f1 / f<-1.0,0.0<f2 / f<1.0,-2.0<f3 / f<-1.0,2.0<f4 / f<3.0,1.0<f5 / f<2.0,-2.0<f6 / f<-1.0。

[0006] Preferably, the first lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the second lens satisfies the relationship: 2.0≤N d ≤2.3, 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: 1.5≤N d ≤1.8, V d ≥50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; where N d is the refractive index, V d is the Abbe constant.

[0007] Preferably, the axial distances between the lenses satisfy the following relationship: the air gap between the first lens and the aperture is 4.5-5.0 mm; the air gap between the aperture and the second lens is 0.0-0.5 mm; the second lens and the third lens are bonded sheets, and the air gap is 0 mm; the air gap between the third lens and the fourth lens is 0.5-1.0 mm; the air gap between the fourth and the fifth lenses is 0.1-0.5 mm; the fifth lens and the sixth lens are bonded sheets, and the air gap is 0 mm.

[0008] Preferably, the fourth lens is an aspherical lens. The aspherical curve equation is expressed as:

[0009]

[0010] Among them, Z is the height of the aspheric surface from the vertex of the aspheric surface when it is at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order coefficients.

[0011] Preferably, the total optical length TTL of the optical system and the focal length f of the optical system satisfy the following relationship: TTL / f≤7.0.

[0012] Preferably, the F number of the optical system is ≤1.8.

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

[0014] Preferably, the aperture is arranged between the first lens and the second lens, and a filter is arranged on the image side of the sixth lens, and the filter is made of an equivalent glass plate.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] 1. The imaging angle of the lens to the object is greater than 127 degrees. It has the advantages of ultra-high 8M imaging clarity, large aperture, low tolerance sensitivity and good high and low temperature stability. At the same time, it can monitor the scene outside the car more comprehensively.

[0017] 2. Through the reasonable matching of optical lenses, the system structure is compact and reasonable, easy to assemble, with low tolerance sensitivity, and more suitable for large-scale high-yield production;

[0018] 3. The all-glass structure has high stability and can adapt to harsh environments. It also gives full play to the advantages of aspherical lenses in correcting aberrations. While meeting high-definition imaging, it has a smaller lens outer diameter and shorter total optical length to ensure the miniaturization of the lens.

[0019] 4. Able to make good compensation for focal plane displacement at high and low temperatures, and have adaptability to complex environments;

[0020] 5. The axial chromatic aberration, vertical chromatic aberration and high-order chromatic aberration are corrected to ensure that the imaging system can have high imaging quality even at a large angle.

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the optical structure of an embodiment of the utility model;

[0023] Figure 2 A full-band axial chromatic aberration diagram of an embodiment of the utility model;

[0024] Figure 3 This is a vertical axis chromatic aberration diagram of the full working band of an embodiment of the utility model;

[0025] Figure 4 This is a field curvature distortion diagram for the entire working band of an embodiment of the utility model.

[0026] In the figure: STO-aperture; L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; L5-equivalent glass plate; IMA-imaging surface. DETAILED DESCRIPTION

[0027] In order to make the above features and advantages of the present invention more obvious and easy to understand, embodiments are given below with reference to the accompanying drawings for detailed description as follows.

[0028] like Figures 1 to 4 As shown, a six-piece 8M front-view optical system, the optical lens is provided with a first lens, an aperture, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in sequence from the object side to the image side. Among them, the first lens is a glass lens with negative focal length, which can adjust large-angle light. The fourth lens is a glass aspherical surface, which has the function of reducing the distortion of the optical system. The second lens and the third lens, the fifth lens and the sixth lens are a cemented lens group. Reasonable lens matching enables the optical system to achieve a six-piece, 8M, ultra-wide-angle, large aperture, day and night confocal, and low-temperature drift design, while the on-axis and off-axis aberrations are well corrected, with good imaging quality, such as Figures 2 to 4 The technical indicators achieved by the optical system of this embodiment are as follows:

[0029] (1) Focal length: 3.0 ≤ EFFL ≤ 4.0 mm;

[0030] (2) Aperture F ≤ 1.8;

[0031] (3) Field of view: 2w ≥ 127°;

[0032] (4) Working band: visible light band.

[0033] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:

[0034]

[0035]

[0036] The aspheric coefficients of the aspheric lenses of the optical system of this embodiment are as follows:

[0037]

[0038] The optical system of the embodiment of the utility model reasonably distributes the optical focal length, surface shape, center thickness of each lens and the axial distance between each lens, etc., of each lens, thereby meeting the imaging performance requirements of the six-piece lens 8M, reducing the total length of the lens and the radial size of each lens, thereby miniaturizing the lens group.

[0039] The present invention is not limited to the above-mentioned best implementation mode. Anyone can derive other various forms of six-piece 8M front-view optical systems under the inspiration of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

1. A six-element 8M front-view optical system, comprising an optical system, characterized in that: The optical system consists of a first lens, an aperture, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are arranged in sequence from left to right along the incident optical path of the light. Without considering the backcurvature caused by the aspheric coefficient, the first lens is a meniscus concave negative lens; the second lens is a biconvex positive lens; the third lens is a biconcave negative lens; the fourth lens is a meniscus convex positive lens; the fifth lens is a biconvex positive lens; the sixth lens is a meniscus concave negative lens; the first lens, the second lens, the third lens, the fifth lens and the sixth lens are glass spherical lenses, the fourth lens is a glass aspheric lens, wherein the second lens and the third lens, the fifth lens and the sixth lens are a cemented lens group.

2. The six-piece 8M front-view optical system according to claim 1, characterized in that: The object side surface of the first lens is convex, and the image side surface is concave; the object side surface of the second lens is convex, and the image side surface is convex; the object side surface of the third lens is concave, and the image side surface is concave; the object side surface of the fourth lens is concave, and the image side surface is convex; the object side surface of the fifth lens is convex, and the image side surface is convex; the object side surface of the sixth lens is concave, and the image side surface is convex.

3. The six-piece 8M front-view optical system according to claim 1, characterized in that: 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 ratio with f: -2.0 <f1 / f<-1.0,0.0<f2 / f<1.0,-2.0<f3 / f<-1.0,2.0<f4 / f<3.0,1.0<f5 / f<2.0,-2.0<f6 / f<-1.0。 4. The six-piece 8M front-view optical system according to claim 1, characterized in that: The first lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the second lens satisfies the relationship: 2.0≤N d ≤2.3, 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: 1.5≤N d ≤1.8, V d ≥50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; where N d is the refractive index, V d is the Abbe constant.

5. The six-piece 8M front-view optical system according to claim 1, characterized in that: The axial distances between the lenses satisfy the following relationship: the air gap between the first lens and the aperture is 4.5-5.0 mm; the air gap between the aperture and the second lens is 0.0-0.5 mm; the second lens and the third lens are bonded sheets, and the air gap is 0 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 fifth lens is 0.1-0.5 mm; the fifth lens and the sixth lens are bonded sheets, and the air gap is 0 mm.

6. The six-piece 8M front-view optical system according to claim 1, characterized in that: The fourth lens is an aspherical lens, and the aspherical curve equation is: Where Z is the height of the aspheric surface from the vertex of the aspheric surface when the aspheric surface is at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order coefficients.

7. The six-piece 8M front-view optical system according to claim 1, characterized in that: The total optical length TTL of the optical system and the focal length f of the optical system satisfy the following condition: TTL / f≤7.

0.

8. The six-piece 8M front-view optical system according to claim 1, characterized in that: The F number of the optical system is ≤1.

8.

9. The six-piece 8M front-view optical system according to claim 1, characterized in that: The image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.

0.

10. The six-piece 8M front-view optical system according to claim 1, characterized in that: The aperture is arranged between the first lens and the second lens, and a filter is arranged on the image side of the sixth lens.

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