An ultra-wide-angle lens suitable for a front dual-camera module and a working method

Abstract

The application relates to a super-wide-angle lens suitable for a front binocular camera module and a working method, wherein 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 arranged in sequence along the light incidence direction; the fourth lens and the fifth lens are glued into a glued lens group; the lens has the advantages of an imaging angle greater than 120 degrees for an object, higher imaging definition, a large light aperture, lower tolerance sensitivity, better high-low temperature stability and the like; the front scene of a vehicle can be monitored more comprehensively; the system structure is compact and reasonable through reasonable matching of the optical lenses; the overall volume is reduced; the system is easy to assemble; the tolerance sensitivity is low; the system is more suitable for large-scale high-yield production; axial chromatic aberration, vertical chromatic aberration and high-order chromatic aberration are corrected; and the imaging system can also have higher imaging quality at a large angle.

Description

TECHNICAL FIELD

[0001] The application relates to an ultra-wide-angle lens suitable for a front binocular camera module and a working method. BACKGROUND

[0002] In order to monitor the environment around the vehicle, sensors are needed to perceive pedestrians and obstacles in the front of the road around the vehicle and obtain the distance of the obstacles around the vehicle, so as to provide a basis for subsequent vehicle control (such as driving and braking or controlling the direction, etc.). There are many common sensors, which can be specifically divided into laser radar sensors, millimeter wave radar sensors, ultrasonic sensors and camera image perception according to the requirements of the vehicle environment perception. The vehicle-mounted binocular camera module, as a kind of camera image perception, also has its own advantages, can complete 3D stereoscopic recognition, can complete target tracking, position prediction and realize target speed detection in cooperation with the millimeter wave radar. The main problems of the current vehicle-mounted binocular camera module are small field of view, high cost, complex system and difficult product miniaturization. SUMMARY

[0003] In view of the deficiencies of the prior art, the application provides an ultra-wide-angle lens suitable for a front binocular camera module and a working method. While realizing clear imaging of a wide angle of 120°, the lens has a small size, high environmental stability and the like.

[0004] The application adopts the following technical scheme: an ultra-wide-angle lens suitable for a front binocular camera module, which is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the light incident direction, and the fourth lens and the fifth lens are glued into a glued lens group.

[0005] Further, 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 double-concave negative lens, the object side surface of which is a concave 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 double-concave negative lens, the object side surface of which is a concave surface, and the image side surface is a concave surface; and the sixth 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.

[0006] Further, 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] Further, the air gap between the first lens and the second lens is 2.5-3.0 mm; the air gap between the second lens and the third lens is 0.1-0.5 mm; the air gap between the third lens and the diaphragm is 0.1-0.5 mm; the air gap between the diaphragm and the fourth lens is 0.1-0.5 mm; and the air gap between the fifth lens and the sixth lens is 0.5-1.0 mm.

[0008] Further, 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; and the sixth lens satisfies the relationship: 1.7≤N d ≤2.0, V d ≤50.0; wherein N d is the refractive index, and V d is the Abbe number.

[0009] Further, 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 ratios: -2.0

[0010] Further, the aspherical lens curve equation expression of the first lens and the sixth lens is:

[0011]

[0012] wherein Z is the sagittal height of the aspherical surface at a height of h 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 high-order coefficients.

[0013] Further, a total optical length TTL of the lens and a focal length f of the optical system satisfy TTL / f<=6.0, and an image height H of the lens and the focal length f of the optical system satisfy H / f<=1.0.

[0014] Further, a rear side of the sixth lens is provided with a filter.

[0015] A working method of the ultra-wide-angle lens suitable for the front binocular camera module is as follows: when light is incident, the light path sequentially enters the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, the sixth lens, and finally forms an image on the image plane.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1. The lens has an imaging angle of more than 120 degrees for an object, and has the advantages of high imaging clarity, large light aperture, low tolerance sensitivity, and good high-low temperature stability, etc.

[0018] 2. By reasonably matching each optical lens, the system structure is compact and reasonable, the overall volume is reduced, assembly is easy, tolerance sensitivity is low, and it is more suitable for large-scale high-yield production.

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

[0020] 4. Each axial chromatic aberration, sagittal chromatic aberration and high-order chromatic aberration is corrected, so that the imaging system can also have high imaging quality at a large angle. BRIEF DESCRIPTION OF DRAWINGS

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

[0022] Figure 2 is the full working waveband axial chromatic aberration diagram of the present application;

[0023] Figure 3 is the full working waveband sagittal chromatic aberration diagram of the present application;

[0024] Figure 4 is the full working waveband field curvature distortion diagram of the present application.

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

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

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

[0028] In this embodiment, the first lens is a meniscus negative lens with a convex object side and a concave image side; the second lens is a biconcave negative lens with a concave object side and a concave image side; the third lens is a biconvex positive lens with a convex object side and a convex image side; the fourth lens is a biconvex positive lens with a convex object side and a convex image side; the fifth lens is a biconcave negative lens with a concave object side and a concave image side; and the sixth lens is a biconvex positive lens with a convex object side and a convex image side.

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

[0030] More specifically, the first lens is a glass aspherical lens with negative optical power, which adjusts light at large angles while reducing optical system distortion. The fourth and fifth lenses form an achromatic cemented doublet. This rational lens combination enables the optical system to achieve a compact size, a 120° ultra-wide angle of view, a large aperture, day and night confocal focus, and low temperature drift. It also provides good correction for on-axis and off-axis aberrations, resulting in good image quality, such as... Figures 2 to 4 As shown.

[0031] In this embodiment, the air gap between the first lens and the second lens is 2.5–3.0 mm; the air gap between the second lens and the third lens is 0.1–0.5 mm; the air gap between the third lens and the aperture stop is 0.1–0.5 mm; the air gap between the aperture stop and the fourth lens is 0.1–0.5 mm; and the air gap between the fifth lens and the sixth lens is 0.5–1.0 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≤N d ≤ 2.0, V d ≤ 50.0; the sixth lens satisfies the relationship: 1.7≤N d ≤ 2.0, V d ≤ 50.0; wherein N d is the refractive index, V d is the Abbe number.

[0033] In the 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 ratios: -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, and 1.0 < f6 / f < 2.0.

[0034] In the embodiment, the aspherical lens curve equation expression of the first lens and the sixth lens is:

[0035]

[0036] wherein Z is the sagittal height of the aspherical surface at a height of h 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 high-order coefficients.

[0037] In the 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 the embodiment, the F number of the optical system is ≤1.6.

[0039] In the embodiment, the rear side of the sixth lens is provided with a filter.

[0040] The technical indexes achieved by the optical system in the 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 angle: 2w≥120°;

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

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

[0046]

[0047]

[0048] The aspheric coefficients of each aspheric lens of the optical system of the embodiment are as follows:

[0049]

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

[0051] The optical system of the embodiment, by reasonably allocating the optical power, surface shape, central thickness of each lens, and on-axis distance between each lens, etc., while meeting the 120° ultra-wide-angle imaging performance requirements of the lens, reduces the total length of the lens and the radial size of each lens, and achieves miniaturization of the lens group.

[0052] Unless otherwise stated, if any of the technical solutions disclosed in the present application discloses a numerical range, the disclosed numerical range is a preferred numerical range, and any person skilled in the art should understand that the preferred numerical range is only one of the many implementable numerical values with more obvious technical effects or representative values. Since there are too many values, it is impossible to enumerate them all, so the present application only discloses some values to illustrate the technical solutions of the present application, and the above-mentioned enumerated values should not constitute a limitation on the protection scope of the present application.

[0053] If the terms "first", "second", etc. are used to limit the components in this document, those skilled in the art should know that the use of "first", "second" is only for the convenience of distinguishing the components, and the above terms have no special meaning unless otherwise stated.

[0054] If the present application discloses or involves components or structural parts that are fixedly connected to each other, unless otherwise stated, the fixed connection can be understood as being able to be disassembled (for example, connected by bolts or screws), or as being understood as being fixedly connected (for example, riveted, welded), and of course, the fixed connection can also be replaced by an integral structure (for example, manufactured by casting process) (except for obvious cases that cannot be replaced by integral forming process).

[0055] In addition, the terms used to indicate the position relationship, such as "vertical", "horizontal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, in any of the technical solutions disclosed in the present application are based on the position relationship shown in the drawings, and are only used for the convenience of describing the present patent, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present patent, and the terms used to indicate the shape in any of the technical solutions disclosed in the present application include shapes similar, similar or close to the shape unless otherwise stated.

[0056] Any of the components provided by the present application can be assembled from a plurality of individual components, or can be a single component manufactured by an integral molding process.

[0057] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical solutions of the present application, they should be included in the technical solution range of the present application claimed.

Claims

1. A super wide-angle lens suitable for a front dual-camera module, characterized in that: The lens is composed of a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens arranged in sequence along the light incident direction, the fourth lens and the fifth lens are glued into a glued lens group; the first lens is a meniscus concave negative lens, the object side surface is a convex surface, and the image side surface is a concave surface; the second lens is a double-concave negative lens, the object side surface is a concave surface, and the image side surface is a concave surface; the third lens is a double-convex positive lens, the object side surface 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 is a convex surface, and the image side surface is a convex surface; the fifth lens is a double-concave negative lens, the object side surface is a concave surface, and the image side surface is a concave surface; and the sixth lens is a double-convex positive lens, the object side surface is a convex surface, and the image side surface is a convex surface; 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; 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 ratios: -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, and 1.0 < f6 / f < 2.

0.

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

3. 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; wherein N d is the refractive index, and V d is the Abbe number.

4. The ultra-wide-angle lens according to claim 1, characterized in that: The aspherical lens curve equation expression of the first lens and the sixth lens is: wherein z is the sagittal height of the aspherical surface at a height of h along the optical axis, c is the paraxial curvature of the aspherical surface, r=1 / c, k is the conic constant, and α1, α2, α3, α4, α5, α6, α7 and α8 are high-order coefficients.

5. 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 lens satisfy TTL / f≤6.0, and the image height H of the lens and the focal length f of the lens satisfy H / f≤1.

0.

6. The ultra-wide-angle lens according to claim 1, characterized in that: The rear side of the sixth lens is provided with a filter.

7. A working method of the super wide-angle lens suitable for the front dual camera module, adopting the super wide-angle lens according to any one of claims 1-6, characterized in that: When light is incident, the light path sequentially enters the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens and the sixth lens, and finally forms an image on the image plane.

Images