An ultra-wide-angle 8M front-view optical system

Abstract

The utility model relates to an ultra-wide-angle 8M front-view optical system, comprising a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens and a seventh lens arranged in sequence from left to right along the incident light path of light; the first lens is a meniscus concave negative lens, the second lens is a meniscus concave negative lens, the third lens is a biconvex positive lens, the fourth lens is a biconvex positive lens, the fifth lens is a biconvex positive lens, the sixth lens is a biconcave negative lens, and the seventh lens is a biconvex positive lens. The utility model has a reasonable design and a simple structure. By reasonably allocating the focal length, surface shape, center thickness of each lens and axial distance between each lens, the utility model can meet the requirements of the ultra-wide-angle imaging performance of the lens 8M to replace the requirements of the front-view wide-angle camera and the front-view narrow-angle camera, while reducing the total length of the lens and the radial size of each lens, so as to miniaturize the lens group.

Description

Technical Field

[0001] The utility model relates to an ultra-wide-angle 8M front-view optical system. Background Art

[0002] In autonomous vehicles, the perception system is mainly composed of sensors such as cameras, millimeter-wave radars, and lidars (optional). As the main environmental perception sensor, the camera plays a very important role. It can achieve 360° comprehensive visual perception, make up for the shortcomings of radar in object recognition, and is the sensor closest to human vision. Therefore, the vehicle-mounted camera is one of the key equipment in the field of autonomous driving. The front-view camera installed on the front windshield is used to realize the visual perception and recognition function of driving. According to the function, it can be divided into the front-view main camera, the front-view narrow-angle camera, and the 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 popularization. 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 ultra-wide-angle 8MP lens is installed on a large scale, this camera can be omitted, thereby reducing costs and increasing market popularity. Utility Model Content

[0003] The utility model improves the above-mentioned problem, that is, the technical problem to be solved by the utility model is to provide an ultra-wide-angle 8M forward-looking optical system, which realizes 8MP ultra-wide-angle imaging while realizing the visual perception and recognition functions of driving, thereby replacing the forward-looking wide-angle camera and the forward-looking narrow-angle camera, realizing a single-lens forward-looking camera module, greatly reducing costs to increase market popularity.

[0004] The utility model is constructed as follows: it comprises a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from left to right along the incident optical path of light; the air interval between the first lens and the second lens is 1.0-1.5mm; the air interval between the second lens and the third lens is 1.5-2.0mm; the air interval between the third lens and the aperture is 0.1-0.5mm; the air interval between the aperture and the fourth lens is 0.1-0.5mm; the air interval between the fourth lens and the fifth lens is 0.1-0.5mm; the fifth lens and the sixth lens are a cemented lens group, and the air interval is 0mm; the air interval between the sixth lens and the seventh lens is 0.5-1.0mm.

[0005] Furthermore, the first lens satisfies the relationship: 1.7≤N d ≤2.0, 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: 1.5≤N d ≤1.8, V d ≥50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the seventh 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.

[0006] Furthermore, 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 biconvex positive lens, whose object side surface is convex 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.

[0007] Furthermore, 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 f respectively. 1 、f 2 、f 3 、f 4 、f 5 、f 6 、f 7 , where f 1 、f 2 、f 3 、f 4 、f 5 、f 6 、f 7 Satisfies the following ratio with f: -2.0 <f 1 / f<-1.0,4.0 <f 2 / f<5.0,2.0 <f 3 / f<3.0,1.0 <f 4 / f<2.0,1.0 <f 5 / f<2.0,-1.0 <f 6 / f<0.0,1.0 <f 7 / f<2.0.

[0008] Furthermore, the first lens, the second lens, and the seventh lens are glass aspherical lenses, the third lens, the fourth lens, the fifth lens, and the sixth lens are glass spherical lenses, and the fifth lens and the sixth lens are a cemented lens group.

[0009] Furthermore, the first lens, the second lens, and the seventh lens are all aspherical lenses, and the aspherical curve equation is expressed as:

[0010] ;

[0011] Where Z is the height of the aspheric surface from the vertex of the aspheric surface at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; α 1 , α 2 , α 3 , α 4 , α 5 , α 6 , α 7 , α 8 All are high-order coefficients.

[0012] Furthermore, a first equivalent glass plate, a second equivalent glass plate and an imaging surface are sequentially arranged on the rear side of the seventh lens.

[0013] Furthermore, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤5.0.

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

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

[0016] Compared with the prior art, the utility model has the following beneficial effects: 1. The imaging angle of the lens to the object is greater than 170 degrees, and it has the advantages of ultra-high 8M imaging clarity, ultra-wide angle, large aperture, low tolerance sensitivity and good high and low temperature stability, etc. At the same time, it can monitor the scene outside the vehicle more comprehensively; 2. By reasonably matching various 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; 3. It adopts a full-glass structure with high stability and can adapt to harsh environments. At the same time, it gives full play to the advantages of aspheric lenses in correcting aberrations, meets high-definition imaging, and has a smaller lens outer diameter and a shorter optical total length to ensure the miniaturization of the lens; 4. It can make good compensation for the focus plane displacement at high and low temperatures, and has adaptability to complex environments; 5. It corrects various axial chromatic aberrations, vertical axis chromatic aberrations and high-order chromatic aberrations to ensure that the imaging system can have high imaging quality at large angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the optical structure of an embodiment of the utility model;

[0018] Figure 2 This is the axial chromatic aberration diagram of the full working band of the embodiment of the utility model;

[0019] Figure 3 This is a vertical axis chromatic aberration diagram of the entire working band of the embodiment of the utility model;

[0020] Figure 4 This is a field curvature distortion diagram of the full working band of the embodiment of the utility model;

[0021] In the figure: L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; L5-fifth lens; L6-sixth lens; L7-seventh lens; L8-first equivalent glass plate; L9-second equivalent glass plate; IMA-imaging surface; STO-aperture. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] Example: Figures 1 to 4 As shown, the utility model provides an ultra-wide-angle 8M front-view optical system, including a first lens L1, a second lens L2, a third lens L3, an aperture STO, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a seventh lens L7, which are arranged in sequence from left to right along the incident light path of the light;

[0024] Without considering the backcurvature 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 biconvex positive lens, whose object side surface is convex 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.

[0025] The first lens and the second lens are aspherical glass lenses that can reduce the distortion of the optical system. The lens with negative focal length can adjust the light at a large angle. The fifth lens and the sixth lens form an achromatic doublet. The reasonable lens combination enables the optical system to achieve 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, and the imaging quality is good.

[0026] In an embodiment of the present utility model, the first lens satisfies the relationship: 1.7≤N d ≤2.0, 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: 1.5≤N d ≤1.8, V d ≥50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the seventh 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.

[0027] In the embodiment of the utility model, the air gap between the first lens and the second lens is 1.0-1.5 mm; the air gap between the second lens and the third lens is 1.5-2.0 mm; the air gap between the third lens and the aperture is 0.1-0.5 mm; the air gap between the aperture and the fourth lens is 0.1-0.5 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 a cemented lens group, and the air gap is 0 mm; the air gap between the sixth lens and the seventh lens is 0.5-1.0 mm.

[0028] In the embodiment of the utility model, 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 f respectively. 1 、f 2 、f 3 、f 4 、f 5 、f 6 、f 7 , where f 1 、f 2 、f 3 、f 4 、f 5 、f 6 、f 7 The ratio with f is -2.0 <f 1 / f<-1.0,4.0 <f 2 / f<5.0,2.0 <f 3 / f<3.0,1.0 <f 4 / f<2.0,1.0 <f 5 / f<2.0,-1.0 <f 6 / f<0.0,1.0 <f 7 / f<2.0.

[0029] In the embodiment of the utility model, the first lens, the second lens and the seventh lens are glass aspherical lenses, the third lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses, and the fifth lens and the sixth lens are cemented lens groups.

[0030] In the embodiment of the utility model, the first lens, the second lens and the seventh lens are all aspherical lenses, and the aspherical curve equation is expressed as:

[0031] ;

[0032] Where Z is the height of the aspheric surface from the vertex of the aspheric surface at a height of r along the optical axis; c is the paraxial curvature of the aspheric surface; k is the cone constant; α 1 , α 2 , α3 , α 4 , α 5 , α 6 , α 7 , α 8 All are high-order coefficients.

[0033] In the embodiment of the utility model, a first equivalent glass plate L8, a second equivalent glass plate L9 and an imaging surface IMA are sequentially arranged on the rear side of the seventh lens.

[0034] In the embodiment of the utility model, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤5.0.

[0035] In the embodiment of the utility model, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≤1.0.

[0036] In the embodiment of the utility model, the F number of the optical system is ≤1.6.

[0037] In the embodiment of the present invention, the aperture of the optical system is located after the third lens S2.

[0038] The technical indicators achieved by the optical system of the embodiment of the utility model are as follows: (1) focal length: 4.0≤EFFL≤5.0mm; (2) aperture F≤1.6; (3) field of view: 2w≥170°; (4) working band: visible light band.

[0039] To achieve the above design parameters, the specific design parameters of the optical system of the embodiment of the utility model are shown in Table 1 below:

[0040]

[0041] Table 1

[0042] The aspheric coefficients of the aspheric lenses of the optical system of the embodiment of the utility model are as follows in Table 2:

[0043]

[0044] Table 2

[0045] In the embodiment of the utility model, the optical system reduces the total length of the lens and the radial size of each lens while meeting the 8M ultra-wide-angle imaging performance requirements of the lens by reasonably allocating the optical focal length, surface shape, center thickness of each lens and the axial distance between each lens, thereby miniaturizing the lens group.

[0046] Unless otherwise stated, any technical solution disclosed in the above utility model, if it discloses a numerical range, then the disclosed numerical range is a preferred numerical range. Any technician in the field should understand that the preferred numerical range is only a numerical value with a more obvious technical effect or representative value among many feasible numerical values. Since there are too many numerical values ​​to be exhaustive, the utility model discloses only some numerical values ​​to illustrate the technical solution of the utility model, and the numerical values ​​listed above should not constitute a limitation on the scope of protection of the utility model.

[0047] At the same time, if the above-mentioned utility model discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connected by bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except when it is obviously impossible to use an one-piece molding process).

[0048] If the words "first", "second" and so on are used in this article to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of description to distinguish the components. Unless otherwise stated, the above words have no special meaning.

[0049] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the above utility model include states or shapes that are approximate, similar or close thereto.

[0050] Any component provided by the utility model can be assembled from multiple separate components, or can be a separate component manufactured by an integrated forming process.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the utility model, which should be included in the scope of the technical solution for protection of the utility model.

Claims

1. An ultra-wide-angle 8M forward-looking optical system, characterized in that: The invention comprises a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are arranged in sequence from left to right along the incident optical path of the light; the air interval between the first lens and the second lens is 1.0-1.5 mm; the air interval between the second lens and the third lens is 1.5-2.0 mm; the air interval between the third lens and the aperture is 0.1-0.5 mm; the air interval between the aperture and the fourth lens is 0.1-0.5 mm; the air interval between the fourth lens and the fifth lens is 0.1-0.5 mm; the fifth lens and the sixth lens are a cemented lens group, and the air interval is 0 mm; the air interval between the sixth lens and the seventh lens is 0.5-1.0 mm.

2. The ultra-wide-angle 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: 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: 1.5≤N d ≤1.8, V d ≥50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; the seventh 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.

3. The ultra-wide-angle 8M front-view optical system according to claim 1, characterized in that: 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 biconvex positive lens, whose object side surface is convex 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.

4. The ultra-wide-angle 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, the sixth lens and the seventh lens are f1, f2, f3, f4, f5, f6, f7 respectively, wherein f1, f2, f3, f4, f5, f6, f7 and f satisfy the following ratios: -2.0< f1 / f <-1.0, 4.0< f2 / f <5.0, 2.0< f3 / f <3.0, 1.0< f4 / f <2.0, 1.0< f5 / f <2.0, -1.0< f6 / f <0.0, 1.0< f7 / f <2.

0.

5. The ultra-wide-angle 8M front-view optical system according to claim 1, characterized in that: The first lens, the second lens and the seventh lens are glass aspherical lenses, the third lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses, and the fifth lens and the sixth lens are cemented lens groups.

6. The ultra-wide-angle 8M front-view optical system according to claim 1, characterized in that: The first lens, the second lens and the seventh lens are all 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.

7. The ultra-wide-angle 8M front-view optical system according to claim 1, characterized in that: The rear side of the seventh lens is sequentially provided with a first equivalent glass plate, a second equivalent glass plate and an imaging surface.

8. The ultra-wide-angle 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: TTL / f≤5.

0.

9. The ultra-wide-angle 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 ultra-wide-angle 8M front-view optical system according to claim 1, characterized in that: The F number of the optical system is ≤1.6.

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