Ultra-wide-angle lens suitable for front binocular camera module

Abstract

The utility model relates to an ultra-wide-angle lens suitable for a front binocular camera module. An optical system is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the incident direction of light, and the fourth lens and the fifth lens are glued to form a glued lens group. The imaging angle of the camera lens to an object is larger than 120 degrees, meanwhile, the camera lens has the advantages of being high in imaging definition, large in clear aperture, low in tolerance sensitivity, good in high-temperature and low-temperature stability and the like, meanwhile, scenes in front of a vehicle can be monitored more comprehensively, and through reasonable matching of all the optical lenses, the system is compact and reasonable in structure, and the system is convenient to use. The imaging system is simple in structure, low in cost, easy to assemble, low in tolerance sensitivity and more suitable for large-scale high-yield production, the overall size is reduced, axial chromatic aberration, vertical-axis chromatic aberration and high-order chromatic aberration are corrected, and it is guaranteed that the imaging system can have high imaging quality even at a large angle.

Description

Technical Field

[0001] The invention relates to an ultra-wide-angle lens suitable for a front binocular camera module. Background Art

[0002] If you want to monitor the environment around the vehicle, you need sensors to sense pedestrians and obstacles around the vehicle and in front of the road, and get the distance of obstacles around the vehicle to provide a basis for subsequent vehicle control (such as driving and braking or controlling direction, etc.). There are many common sensors. According to the requirements for the perception of the vehicle's surrounding environment, they can be specifically divided into four types: lidar sensors, millimeter-wave radar sensors, ultrasonic sensors, and camera image perception. As a type of camera image perception, the on-board binocular camera module also has its own advantages. It can complete 3D stereo recognition functions, target tracking, position prediction, and cooperate with millimeter-wave radar to detect target speed. At present, the main problems with the on-board binocular camera module are small field of view, high cost, complex system, and difficulty in miniaturization. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides an ultra-wide-angle lens suitable for a front binocular camera module, which has a small size and high environmental stability while achieving a wide-angle 120° clear imaging.

[0004] The solution adopted by the present invention to solve the technical problem is an ultra-wide-angle lens suitable for a front binocular camera module: the lens is composed of a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the incident direction of light, and the fourth lens and the fifth lens are glued to form a glued lens group.

[0005] 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 double concave negative lens, whose object side surface is concave and whose image side surface is concave; the third lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the fourth lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the fifth lens is a double concave negative lens, whose object side surface is concave and whose image side surface is concave; the sixth lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex.

[0006] Furthermore, the second lens, the third lens, the fourth lens and the fifth lens are glass spherical lenses, and the first lens and the sixth lens are glass aspherical lenses.

[0007] Furthermore, the air gap between the first lens and the second lens is 2.5 to 3.0 mm; the air gap between the second lens and the third lens is 0.1 to 0.5 mm; the air gap between the third lens and the aperture is 0.1 to 0.5 mm; the air gap between the aperture and the fourth lens is 0.1 to 0.5 mm; and the air gap between the fifth lens and the sixth lens is 0.5 to 1.0 mm.

[0008] Furthermore, the first lens satisfies the relationship: 1.6≤N d ≤1.9, V d ≤50.0; the second lens satisfies the relationship: 1.6≤N d ≤1.9, 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: 1.7≤N d ≤2.0, V d ≤50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; where N d is the refractive index, V d is the Abbe constant.

[0009] Furthermore, the focal length of the lens 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,-2.0<f2 / f<-1.0,1.0<f3 / f<2.0,1.0<f4 / f<2.0,-2.0<f5 / f<-1.0,1.0<f6 / f<2.0。

[0010] Furthermore, the aspheric lens curve equations of the first lens and the sixth lens are expressed as:

[0011]

[0012] Among them, Z is the height of the aspheric surface from the vertex of the aspheric surface when it is at a height of h 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.

[0013] Furthermore, the total optical length TTL of the lens and the focal length f of the optical system satisfy: TTL / f≤6.0.

[0014] Furthermore, the image height H of the lens 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 present invention has the following beneficial effects:

[0017] 1. The imaging angle of the lens to the object is greater than 120 degrees. It has the advantages of high imaging clarity, large aperture, low tolerance sensitivity and good high and low temperature stability. At the same time, it can monitor the scene in front of the vehicle more comprehensively.

[0018] 2. Through the reasonable matching of optical lenses, the system structure is compact and reasonable, the overall volume is reduced, it is easy to assemble, the tolerance sensitivity is low, and it is more suitable for large-scale high-yield production;

[0019] 3. The all-glass lens structure can compensate for focal plane displacement at high and low temperatures, and has high adaptability to complex environments;

[0020] 4. 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the optical structure of the present invention;

[0022] Figure 2 It is the full working band axial chromatic aberration diagram of the present invention;

[0023] Figure 3 It is the vertical axis chromatic aberration diagram of the full working band of the present invention;

[0024] Figure 4 It is the field curvature distortion diagram of the full working band of the present invention.

[0025] In the figure: STO-aperture; L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; L5-fifth lens; L6-sixth lens; L7-equivalent glass plate; L8-equivalent glass plate; IMA-imaging surface. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figure 1As shown, an ultra-wide-angle lens suitable for a front binocular camera module: the lens is composed of a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the incident direction of light, and the fourth lens and the fifth lens are glued to form a glued lens group.

[0028] In this embodiment, 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 double concave negative lens, whose object side surface is concave and whose image side surface is concave; the third lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the fourth lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the fifth lens is a double concave negative lens, whose object side surface is concave and whose image side surface is concave; and the sixth lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex.

[0029] In this embodiment, the second lens, the third lens, the fourth lens, and the fifth lens are glass spherical lenses, and the first lens and the sixth lens are glass aspherical lenses.

[0030] More specifically, the first lens is a glass aspherical lens with negative focal length, which adjusts the large-angle light and reduces the distortion of the optical system. The fourth lens and the fifth lens form an achromatic doublet. Reasonable lens matching enables the optical system to achieve a small volume, 120° 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, such as Figures 2 to 4 shown.

[0031] In this embodiment, the air gap between the first lens and the second lens is 2.5 to 3.0 mm; the air gap between the second lens and the third lens is 0.1 to 0.5 mm; the air gap between the third lens and the aperture is 0.1 to 0.5 mm; the air gap between the aperture and the fourth lens is 0.1 to 0.5 mm; and the air gap between the fifth lens and the sixth lens is 0.5 to 1.0 mm.

[0032] In this embodiment, the first lens satisfies the relationship: 1.6≤N d ≤1.9, V d ≤50.0; the second lens satisfies the relationship: 1.6≤N d ≤1.9, 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: 1.7≤Nd ≤2.0, 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.

[0033] In this embodiment, the focal length of the lens 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,-2.0<f2 / f<-1.0,1.0<f3 / f<2.0,1.0<f4 / f<2.0,-2.0<f5 / f<-1.0,1.0<f6 / f<2.0。

[0034] In this embodiment, the aspheric lens curve equations of the first lens and the sixth lens are expressed as follows:

[0035]

[0036] Among them, Z is the height of the aspheric surface from the vertex of the aspheric surface when it is at a height of h 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.

[0037] In this embodiment, the total optical length TTL of the lens and the focal length f of the optical system satisfy: TTL / f≤6.0, and the image height H of the lens and the focal length f of the optical system satisfy: H / f≤1.0.

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

[0039] In this embodiment, a filter is disposed on the rear side of the sixth lens.

[0040] The technical indicators achieved by the optical system of this embodiment are as follows:

[0041] (1) Focal length: 5.0 ≤ EFFL ≤ 6.0 mm;

[0042] (2) Aperture F ≤ 1.6;

[0043] (3) Field of view: 2w ≥ 120°;

[0044] (4) Working band: visible light band.

[0045] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:

[0046]

[0047]

[0048] The aspheric coefficients of the aspheric lenses of the optical system of this embodiment are as follows:

[0049]

[0050] A working method for an ultra-wide-angle lens suitable for a front binocular camera module: when light is incident, the light path sequentially enters a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, and a sixth lens, and finally forms an image on an image plane.

[0051] The optical system of this embodiment reduces the total length of the lens and the radial size of each lens while meeting the 120° ultra-wide-angle imaging performance requirements of the lens by reasonably allocating the optical power, surface shape, center thickness of each lens, and axial distance between each lens, thereby miniaturizing the lens group.

[0052] Unless otherwise stated, any technical solution disclosed in the present invention disclosed above, if it discloses a numerical range, then the disclosed numerical range is a preferred numerical range, and 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 implementable numerical values. Since there are too many numerical values ​​to be exhaustive, the present invention discloses some numerical values ​​to illustrate the technical solution of the present invention, and the numerical values ​​listed above should not constitute a limitation on the scope of protection of the present invention.

[0053] 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.

[0054] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using 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).

[0055] In addition, the orientations or positional relationships indicated by terms such as "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", and "outside" used in any of the technical solutions disclosed in the above-mentioned invention are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this patent, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent. Unless otherwise stated, the terms used to indicate shapes used in any of the technical solutions disclosed in the above-mentioned invention include shapes that are approximate, similar, or close to them.

[0056] Any component provided by the present invention may be assembled from a plurality of separate components, or may be a separate component manufactured by an integral forming process.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. An ultra-wide-angle lens suitable for a front binocular camera module, characterized in that: The lens is composed of a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the incident direction of light, and the fourth lens and the fifth lens are glued together to form a glued lens group.

2. The ultra-wide-angle lens 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 double concave negative lens, whose object side surface is concave and whose image side surface is concave; the third lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the fourth lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex; the fifth lens is a double concave negative lens, whose object side surface is concave and whose image side surface is concave; the sixth lens is a double convex positive lens, whose object side surface is convex and whose image side surface is convex.

3. The ultra-wide-angle lens according to claim 1, characterized in that: The second lens, the third lens, the fourth lens and the fifth lens are glass spherical lenses, and the first lens and the sixth lens are glass aspherical lenses.

4. The ultra-wide-angle lens according to claim 1, characterized in that: The air gap between the first lens and the second lens is 2.5 to 3.0 mm; the air gap between the second lens and the third lens is 0.1 to 0.5 mm; the air gap between the third lens and the aperture is 0.1 to 0.5 mm; the air gap between the aperture and the fourth lens is 0.1 to 0.5 mm; the air gap between the fifth lens and the sixth lens is 0.5 to 1.0 mm.

5. The ultra-wide-angle lens according to claim 1, characterized in that: The first lens satisfies the relationship: 1.6≤N d ≤1.9, V d ≤50.0; the second lens satisfies the relationship: 1.6≤N d ≤1.9, 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: 1.7≤N d ≤2.0, V d ≤50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; where N d is the refractive index, V d is the Abbe constant.

6. The ultra-wide-angle lens according to claim 1, characterized in that: The focal length of the lens 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,-2.0<f2 / f<-1.0,1.0<f3 / f<2.0,1.0<f4 / f<2.0,-2.0<f5 / f<-1.0,1.0<f6 / f<2.0。 7. The ultra-wide-angle lens according to claim 1, characterized in that: The aspheric lens curve equations of the first lens and the sixth lens are 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 h 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.

8. The ultra-wide-angle lens according to claim 1, characterized in that: The total optical length TTL of the lens and the focal length f of the optical system satisfy the following condition: TTL / f≤6.

0.

9. The ultra-wide-angle lens according to claim 1, characterized in that: The image height H of the lens and the focal length f of the optical system satisfy the following relationship: H / f≤1.

0.

10. The ultra-wide-angle lens according to claim 1, characterized in that: The F number of the optical system is ≤1.6.

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