Low-total-length 8M foresight optical lens

Abstract

The utility model relates to a low total length 8M foresight optical lens, which is characterized in that an optical system of the lens 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 which are sequentially arranged from left to right along a light incident light path. The lenses are made of plastic and glass materials, the first lens, the second lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses, the third lens and the seventh lens are plastic aspheric lenses, and the fifth lens and the sixth lens form a balsaming lens group. By reasonably distributing the focal power and the surface type of each lens, the central thickness of each lens, the distance between the lenses on the optical axis and the like, the total length of the lens and the radial size of each lens are reduced while the requirements of a front-view wide-angle camera and a front-view narrow-angle camera are replaced by the low-total-length 8M ultra-wide-angle imaging performance of the lens; and the lens group is miniaturized.

Description

Technical Field

[0001] The utility model relates to the technical field of lenses, in particular to a front-view optical lens with a low total length of 8M. Background Art

[0002] The vehicle-mounted camera module needs to use lenses with different field of view angles according to different usage scenarios. For example, in the lane departure detection system and the driver fatigue detection system, in order to improve the detection accuracy and reduce the distortion of the edge of the picture, it is necessary to select a lens with a suitable field of view angle range for the vehicle-mounted camera module, generally an ultra-wide-angle lens.

[0003] Among them, the front-view vehicle lens is an important component of the advanced driver assistance system. The driver can use the front-view vehicle lens to detect obstacles in front of the car and avoid driving accidents. According to the function, it can be divided into a front-view main camera, a front-view narrow-angle camera and a front-view wide-angle camera. However, the use of three cameras greatly increases the cost of the entire camera module, which is not conducive to market popularity.

[0004] In order to realize the single-lens module, the front-view optical lens must meet the advantages of 8M high resolution, large field of view angle, good environmental adaptability, etc., but it also has disadvantages such as a large number of lenses and a long total optical length, which is not conducive to the miniaturization of the overall system.

[0005] At present, the Chinese patent "A vehicle-mounted forward-looking optical lens" announcement number CN216870927U has been retrieved, and a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens, a seventh lens, a filter IR, a protective glass CG and an image plane I MA are arranged in sequence along the incident direction of light; wherein the first lens is a glass aspherical lens, and the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all glass spherical lenses; wherein the fifth lens is combined with the sixth lens to form a cemented lens or the fourth lens is combined with the fifth lens to form a cemented lens; although this patent provides a vehicle-mounted forward-looking optical lens with high resolution, large aperture, high resolution, large field of view and low production cost; but its lens cannot replace the forward-looking wide-angle camera and the forward-looking narrow-angle camera to realize a single-lens forward-looking camera module. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the utility model is to provide a low total length 8M forward-looking optical lens. The optical system of the utility model realizes low total length and low-cost 8MP imaging while realizing the visual perception and recognition functions of driving, thereby being able to replace the forward-looking wide-angle camera and the forward-looking narrow-angle camera, and realizing a single-lens forward-looking camera module, thereby greatly reducing costs and increasing market popularity.

[0007] In order to solve the above technical problems, the technical solution of the utility model is:

[0008] A low total length 8M front-view optical lens, the optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens and a seventh lens from left to right along the incident light path; 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 meniscus concave negative lens, the object side surface of which is convex, and the image side surface is concave; the third lens is a meniscus concave negative lens, the object side surface of which is concave, and the image side surface is convex; the fourth lens is a double convex lens A positive lens, whose object side surface is convex 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 double concave negative lens, whose object side surface is concave and whose image side surface is concave; the seventh lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the image side surface of the fifth lens and the object side surface of the sixth lens are cemented to form a cemented lens group, the first, second, fourth, fifth and sixth lenses are glass spherical lenses, and the third and seventh lenses are plastic aspherical lenses.

[0009] 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 ratio with f: -4.0 <f1 / f<-3.0,-3.0<f2 / f<-2.0,-14.0<f3 / f<-13.0,2.0<f4 / f<3.0,1.0<f5 / f<2.0,-2.0<f6 / f<-1.0,3.0<f7 / f<4.0。

[0010] Preferably, the first lens satisfies the relationship: 2.0≤N d ≤2.3, 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: 1.5≤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: 1.7≤N d ≤2.0, V d ≤50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the seventh lens satisfies the relationship: 1.5≤N d ≤1.8, Vd ≥50.0; where N d is the refractive index, V d is the Abbe constant.

[0011] Preferably, the distances between the lenses on the optical axis satisfy the following relationship: the air gap between the first lens and the second lens is 1.5-2.0 mm; the air gap between the second lens and the third lens is 2.5-3.0 mm; the air gap between the third lens and the fourth lens is 0.1-0.5 mm; the air gap between the fourth lens and the aperture is 0.5-1.0 mm; the air gap between the aperture and the fifth lens is 0.1-0.5 mm; the fifth lens and the sixth lens are glued sheets with an air gap of 0 mm; the air gap between the sixth lens and the seventh lens is 0.5-1.0 mm.

[0012] Preferably, the third and seventh lenses are both aspherical lenses, and the aspherical curve equation is expressed as:

[0013]

[0014] 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.

[0015] 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≤11.0.

[0016] Preferably, the F number of the optical system is ≤1.6.

[0017] Preferably, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0.

[0018] Preferably, a filter is disposed on the rear side of the seventh lens.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] 1. The imaging angle of the lens to the object is greater than 194 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;

[0021] 2. Through the reasonable matching of various optical lenses, the system structure is compact and reasonable, with a total length of 17mm, easy to assemble, low tolerance sensitivity, and more suitable for large-scale high-yield production;

[0022] 3. The glass-plastic hybrid structure has lower manufacturing cost and lighter weight, which is conducive to the manufacture and installation of modules;

[0023] 4. Able to make good compensation for focal plane displacement at high and low temperatures, and have adaptability to complex environments;

[0024] 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.

[0025] 6. Give full play to the advantages of aspherical lenses in correcting aberrations, meet the requirements of high-definition imaging, have a smaller lens outer diameter and a shorter total optical length, and ensure the miniaturization of the lens.

[0026] 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

[0027] Figure 1 It is a schematic diagram of the optical structure of the utility model;

[0028] Figure 2 It is the axial chromatic aberration diagram of the full working band of the utility model;

[0029] Figure 3 It is the vertical axis chromatic aberration diagram of the full working band of the utility model;

[0030] Figure 4 It is the field curvature distortion diagram of the full working band of the utility model;

[0031] In the figure: STO-aperture; L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; L5-fifth lens; L6-sixth lens; L7-seventh lens; L8-equivalent glass plate; L9-equivalent glass plate; IMA-imaging surface. DETAILED DESCRIPTION

[0032] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0033] like Figure 1As shown, a low total length 8M front-view optical lens, the optical system is provided with a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture, a fifth lens L5, a sixth lens L6 and a seventh lens L7 in sequence from the object side to the image side; without considering the recurvature caused by the aspheric coefficient, the first lens is a meniscus concave negative lens, whose object side surface is convex and whose image side surface is concave; the second lens is a meniscus concave negative lens, whose object side surface is convex and whose image side surface is concave; the third lens is a meniscus concave negative lens, whose object side surface is concave, The image side surface is convex; the fourth lens is a double convex positive lens, whose object side surface is convex and image side surface is convex; the fifth lens is a double convex positive lens, whose object side surface is convex and image side surface is convex; the sixth lens is a double concave negative lens, whose object side surface is concave and image side surface is concave; the seventh lens is a double convex positive lens, whose object side surface is convex and image side surface is convex; the image side surface of the fifth lens is cemented with the object side surface of the sixth lens to form a cemented lens group; the first, second, fourth, fifth and sixth lenses are glass spherical lenses, and the third and seventh lenses are plastic aspherical lenses.

[0034] The first lens, the second lens and the third lens are negative optical power lenses, which can adjust large-angle light. The third lens is a plastic aspheric surface, which can also reduce the distortion of the optical system. The fifth lens and the sixth lens form an achromatic doublet lens. Reasonable lens matching enables the optical system to achieve low cost, low total length, 8M, ultra-wide angle, large aperture, day and night confocal, and low-temperature drift design. At the same time, the on-axis and off-axis aberrations are well corrected, with good imaging quality.

[0035] 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, where f1, f2, f3, f4, f5, f6, and f7 satisfy the following ratio with f: -4.0 <f1 / f<-3.0,-3.0<f2 / f<-2.0,-14.0<f3 / f<-13.0,2.0<f4 / f<3.0,1.0<f5 / f<2.0,-2.0<f6 / f<-1.0,3.0<f7 / f<4.0。

[0036] The first lens satisfies the relationship: 2.0≤N d ≤2.3, 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: 1.5≤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: 1.7≤N d ≤2.0, V d ≤50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the seventh lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; where N d is the refractive index, V d is the Abbe constant.

[0037] The distances between the lenses on the optical axis satisfy the following relationship: the air gap between the first lens and the second lens is 1.5-2.0 mm; the air gap between the second lens and the third lens is 2.5-3.0 mm; the air gap between the third lens and the fourth lens is 0.1-0.5 mm; the air gap between the fourth lens and the aperture is 0.5-1.0 mm; the air gap between the aperture and the fifth lens is 0.1-0.5 mm; the fifth lens and the sixth lens are glued sheets with an air gap of 0 mm; the air gap between the sixth lens and the seventh lens is 0.5-1.0 mm.

[0038] The third and seventh lenses are both aspherical lenses, and the aspherical curve equation is:

[0039]

[0040] 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.

[0041] The total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤11.0; the F number of the optical system ≤1.6; the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.0; a filter is arranged at the rear side of the seventh lens.

[0042] like Figures 2 to 4 As shown, the technical indicators achieved by the optical system of the utility model embodiment are as follows:

[0043] (1) Focal length: 1.0 ≤ EFFL ≤ 2.0 mm;

[0044] (2) Aperture F ≤ 1.6;

[0045] (3) Field of view: 2w ≥ 194°;

[0046] (4) Working band: visible light band.

[0047] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:

[0048]

[0049] The aspheric coefficients of the aspheric lenses of the optical system of this embodiment are as follows:

[0050]

[0051] The optical system of this embodiment reasonably distributes the optical focal length, surface shape, center thickness of each lens and the distance between each lens on the optical axis, etc., of each lens, thereby meeting the requirements of ultra-wide-angle imaging performance of the lens with a low total length of 8M, reducing the total length of the lens and the radial size of each lens, thereby miniaturizing the lens group.

[0052] The above is only the preferred embodiment of the utility model, and does not limit the utility model in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the technical solution of the utility model still belongs to the protection scope of the technical solution of the utility model.

Claims

1. A low total length 8M front-view optical lens, characterized in that: The optical system of the lens is composed of a first lens, a second lens, a third lens, a fourth lens, an aperture, a fifth lens, a sixth lens and a seventh lens from left to right along the incident light path; the first lens is a meniscus concave negative lens, whose object side surface is convex and whose image side surface is concave; the second lens is a meniscus concave negative lens, whose object side surface is convex and whose image side surface is concave; the third lens is a meniscus concave negative lens, whose object side surface is concave and whose image side surface is convex; the fourth lens is a biconvex positive lens, whose object side surface is convex and whose image side surface is convex; the fifth lens is a biconvex positive lens, whose object side surface is convex and whose image side surface is convex; the sixth lens is a biconcave negative lens, whose object side surface is concave and whose image side surface is concave; the seventh lens is a biconvex positive lens, whose object side surface is convex and whose image side surface is convex; the image side surface of the fifth lens is glued with the object side surface of the sixth lens to form a glued lens group, the first, second, fourth, fifth and sixth lenses are glass spherical lenses, and the third and seventh lenses are plastic aspherical lenses.

2. The low total length 8M front-view optical lens 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, 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 ratio with f: -4.0 <f1 / f<-3.0,-3.0<f2 / f<-2.0,-14.0<f3 / f<-13.0,2.0<f4 / f<3.0,1.0<f5 / f<2.0,-2.0<f6 / f<-1.0,3.0<f7 / f<4.0。 3. The low total length 8M front-view optical lens according to claim 2, characterized in that: The first lens satisfies the relationship: 2.0≤N d ≤2.3, 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: 1.5≤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: 1.7≤N d ≤2.0, V d ≤50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the seventh lens satisfies the relationship: 1.5≤N d ≤1.8, V d ≥50.0; where N d is the refractive index, V d is the Abbe constant.

4. The low total length 8M front-view optical lens according to claim 1, 2 or 3, characterized in that: The distances between the lenses of the optical system on the optical axis satisfy the following relationship: the air gap between the first lens and the second lens is 1.5-2.0 mm; the air gap between the second lens and the third lens is 2.5-3.0 mm; the air gap between the third lens and the fourth lens is 0.1-0.5 mm; the air gap between the fourth lens and the diaphragm is 0.5-1.0 mm; the air gap between the diaphragm and the fifth lens is 0.1-0.5 mm; the fifth lens and the sixth lens are glued sheets with an air gap of 0 mm; the air gap between the sixth lens and the seventh lens is 0.5-1.0 mm.

5. The low total length 8M front-view optical lens according to claim 1, 2 or 3, characterized in that: The third and seventh lenses of the optical system are both aspherical lenses, and the aspherical curve equation is expressed as: 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.

6. The low total length 8M front-view optical lens according to claim 1, 2 or 3, characterized in that: The total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤11.0; the F number of the optical system ≤1.6; the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥1.

0.

7. The low total length 8M front-view optical lens according to claim 1, 2 or 3, characterized in that: A filter is arranged at the rear side of the seventh lens of the optical system.

8. The low total length 8M front-view optical lens according to claim 1, 2 or 3, characterized in that: The technical indicators achieved by the optical system are as follows: (1) Focal length: 1.0 ≤ EFFL ≤ 2.0 mm; (2) Aperture F ≤ 1.6; (3) Field of view: 2w ≥ 194°.

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