Ultra-wide-angle vehicle-mounted lens

Abstract

The present invention relates to the technical field of optical lenses, and in particular to an ultra-wide-angle vehicle-mounted lens. It includes a front lens group with positive optical power, an aperture and a rear lens group with positive optical power from the object side to the image side along the optical axis; the front lens group includes a first lens, a second lens and a third lens from the object side to the image side; the first lens has a negative optical power, its object side surface is convex, and the image side surface is concave; the second lens has a negative optical power, and its object side surface and image side surface are both concave; the third lens has a positive optical power, and its object side surface and image side surface are both convex; the rear lens group includes a fourth lens, a fifth lens and a sixth lens from the object side to the image side; the fourth lens has a positive optical power, and its object side surface and image side surface are both convex; the fifth lens has a negative optical power, and its object side surface and image side surface are both concave; the sixth lens has a positive optical power, and its object side surface and image side surface are both convex. The present invention can make the lens have miniaturization, wide angle and high-quality imaging.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and particularly to an ultra-wide-angle vehicle-mounted lens. Background Art

[0002] In recent years, with the continuous improvement of national requirements for road traffic safety and vehicle safety, as well as the rise of future driverless technologies, vehicle-mounted lenses have become increasingly indispensable important components in vehicles. At the same time, the automotive field has put forward higher and higher quality requirements for vehicle-mounted lenses. Traditional vehicle-mounted lenses have a small aperture, a large number of lenses, and mostly use glass lenses. Such lenses usually have a small field of view, a large volume, and a relatively high price, with a poor overall effect, making it difficult to meet the needs of the existing market. Summary of the Invention

[0003] In view of the above-mentioned disadvantages and deficiencies of the prior art, the present invention provides an ultra-wide-angle vehicle-mounted lens, which solves the problems of small field of view and large volume in the prior art.

[0004] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0005] An embodiment of the present invention provides an ultra-wide-angle vehicle-mounted lens, which sequentially includes a front lens group with positive optical power, an aperture stop, and a rear lens group with positive optical power along the optical axis from the object side to the image side; the front lens group sequentially includes a first lens, a second lens, and a third lens from the object side to the image side; wherein, the optical power of the first lens is negative, its object side is convex, and its image side is concave; the optical power of the second lens is negative, and both its object side and image side are concave; the optical power of the third lens is positive, and both its object side and image side are convex; the rear lens group sequentially includes a fourth lens, a fifth lens, and a sixth lens from the object side to the image side; wherein, the optical power of the fourth lens is positive, and both its object side and image side are convex; the optical power of the fifth lens is negative, and both its object side and image side are concave; the optical power of the sixth lens is positive, and both its object side and image side are convex; the first lens and the third lens are both glass spherical lenses, the second lens, the fourth lens, the fifth lens, and the sixth lens are all plastic aspherical lenses, and the lens satisfies the conditional formula: 0.8 < EFLF / EFLB < 2.0; wherein, EFLF is the focal length of the front lens group of the optical system, and EFLB is the focal length of the rear lens group of the optical system. After satisfying the above conditional formula, by controlling the ratio between the combined focal length of the front lens group and the combined focal length of the rear lens group, the light can enter the rear lens group smoothly from the front lens group, ensuring that the optical system has a good imaging effect.

[0006] Further, the refractive indices and dispersion coefficients of the first lens and the third lens respectively satisfy the following conditions: nd1 > 1.8, vd1 < 46.5, nd3 > 1.8, vd3 < 41.5; where, nd1 is the refractive index of the first lens, vd1 is the dispersion coefficient of the first lens, nd3 is the refractive index of the third lens, and vd3 is the dispersion coefficient of the third lens. After meeting the above conditions, by reasonably controlling the refractive indices and dispersion coefficients of the first lens and the third lens respectively, it is beneficial to improve the chromatic aberration of the optical system, enabling the optical system to form clear images and facilitating volume reduction.

[0007] Further, the first lens satisfies the following conditional formula: 1.8 < ∣D1 / f1∣ < 2.2; where, D1 is the effective aperture of the object side surface of the first lens, and f1 is the effective focal length of the first lens. After meeting the above conditional formula, light can enter the object side surface of the first lens at the maximum incident angle, better realizing the wide-angleization of the optical system.

[0008] Further, the lens satisfies the following conditional formula: FOV > 180°; where, FOV is the total field of view angle of the lens. The optical system can also capture graphic information and form good images within a viewing angle range exceeding 180 degrees.

[0009] Further, the lens satisfies the following conditional formula: 8.6 < TTL / F < 8.7; where, TTL is the total length of the lens, and F is the total focal length of the lens. After meeting the above conditional formula, it is beneficial to realize the miniaturization of the optical system.

[0010] Further, the lens satisfies the following conditional formula: 0.2 < d6 / TTL < 0.25; where, d6 is the distance from the image side surface of the sixth lens to the imaging surface on the optical axis, and TTL is the total length of the lens. After meeting the above conditional formula, it is beneficial for module assembly, and shortens the total length of the optical system, making the structure more compact.

[0011] Further, the lens satisfies the following conditional formula: 0.26 < (R7 + R9) / (R7 - R9) < 0.35; where, R7 is the curvature radius of the object side surface of the fourth lens, and R9 is the curvature radius of the object side surface of the fifth lens. After meeting the above conditional formula, it is beneficial to correct the aberration of the optical system.

[0012] Further, the lens satisfies the following conditional formula: 2.5 < ∣f4 / f5∣ < 2.7; where, f4 is the effective focal length of the fourth lens, and f5 is the effective focal length of the fifth lens. After meeting the above conditional formula, the influence of temperature drift on the optical system can be effectively improved.

[0013] Further, the second lens, the fourth lens, the fifth lens, and the sixth lens satisfy the aspherical lens formula, where the aspherical coefficients satisfy the following equation:

[0014] Z=cy 2 / [1+{1-(1+k)c 2 y 2} 1 / 2 ]+A4y 4 +A6y 6 +A8y 8 +A10y 10 +A12y 12 +A14y 14 +A16y 16

[0015] Among them, Z is the aspheric surface sag, c is the aspheric surface paraxial curvature, y is the lens aperture, k is the cone coefficient, A4 is the 4th aspheric surface coefficient, A6 is the 6th aspheric surface coefficient, A8 is the 8th aspheric surface coefficient, A10 is the 10th aspheric surface coefficient, A12 is the 12th aspheric surface coefficient, A14 is the 14th aspheric surface coefficient, and A16 is the 16th aspheric surface coefficient. After satisfying the above expressions, the ability to correct aberrations that traditional spherical lenses cannot achieve can be achieved, thereby improving the shooting effect of the lens.

[0016] The beneficial effects of the present invention are as follows: the ultra-wide-angle vehicle-mounted lens provided by the present invention is mainly composed of six lenses, and adopts a mixed design of glass spherical lenses and plastic aspherical lenses. By matching reasonable optical focal length and surface shape, and reasonably allocating parameters, the lens has the advantages of miniaturization, wide angle and high-quality imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The structure diagram of the ultra-wide-angle vehicle-mounted lens of Example 1 of the present invention is shown;

[0018] Figure 2 The distortion curve diagram of the ultra-wide-angle vehicle-mounted lens of Example 1 of the present invention is shown;

[0019] Figure 3 The MTF curve diagram of the ultra-wide-angle vehicle-mounted lens of Example 1 of the present invention is shown;

[0020] Figure 4 The schematic diagram of the structure of the ultra-wide-angle vehicle-mounted lens of Embodiment 2 of the present invention is shown;

[0021] Figure 5 The distortion curve diagram of the ultra-wide-angle vehicle-mounted lens of Example 2 of the present invention is shown;

[0022] Figure 6 The MTF curve of the ultra-wide-angle vehicle-mounted lens of Example 2 of the present invention is shown.

[0023] In the figure: the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the object side surface S1 of the first lens, the image side surface S2 of the first lens, the object side surface S3 of the second lens, the image side surface S4 of the second lens, the object side surface S5 of the third lens, the image side surface S6 of the third lens, the aperture S7, the object side surface S8 of the fourth lens, the image side surface S9 of the fourth lens, the object side surface S10 of the fifth lens, the image side surface S11 of the fifth lens, the object side surface S12 of the sixth lens, the image side surface S13 of the sixth lens, and the filter I8. DETAILED DESCRIPTION

[0024] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment provides an ultra-wide-angle vehicle-mounted lens. The optical lens includes a front lens group with positive optical power, an aperture S7 and a rear lens group with positive optical power from the object side to the image side along the optical axis. Among them, the front lens group includes a first lens L1, a second lens L2 and a third lens L3 from the object side to the image side. The first lens L1 has a negative optical power, and its object side surface S1 is a convex surface, and the image side surface S2 is a concave surface. The second lens L2 has a negative optical power, and its object side surface S3 is a concave surface, and the image side surface S4 is also a concave surface. The third lens L3 has a positive optical power, and its object side surface S5 is a convex surface, and the image side surface S6 is also a convex surface. Among them, the rear lens group includes a fourth lens L4, a fifth lens L5 and a sixth lens L6 from the object side to the image side. The fourth lens L4 has a positive optical power, and its object side surface S8 is a convex surface, and the image side surface S9 is also a convex surface. The fifth lens L5 has a negative focal power, and its object side surface S10 is concave, and its image side surface S11 is also concave. The sixth lens L6 has a positive focal power, and its object side surface S12 is convex, and its image side surface S13 is also convex. The lens also includes a filter I8, which is arranged between the sixth lens L6 and the image plane.

[0027] Specifically, the first lens L1 and the third lens L3 are both glass spherical lenses, and the second lens L2, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all plastic aspherical lenses.

[0028] Table 1 (a) shows the surface type, curvature radius, thickness and material of each lens of the ultra-wide-angle vehicle-mounted lens of Example 1. The units of the curvature radius and thickness are both millimeters (mm).

[0029] The design parameters of the lens group of this embodiment 1 are specifically referred to the following table:

[0030] Table 1(a)

[0031]

[0032]

[0033] Table 1(b)

[0034]

[0035] In this embodiment 1, the specific parameters of the lens are shown in the following table:

[0036] Table 1(c)

[0037]

[0038] According to Table 1(a), Table 1(b) and Figure 1 Structural features of the presented optical system.

[0039] The lens shown in Example 1 has the characteristics of large aperture and small size.

[0040] According to Table 1(c) and Figure 2 The distortion curve of the optical system shown, Figure 3 The MTF curve of the optical system shown shows that the lens shown in Example 1 can achieve good imaging.

[0041] Example 2

[0042] like Figure 5 As shown, this embodiment provides an ultra-wide-angle vehicle-mounted lens. The optical lens includes a front lens group with positive optical power, an aperture S7 and a rear lens group with positive optical power from the object side to the image side along the optical axis. Among them, the front lens group includes a first lens L1, a second lens L2 and a third lens L3 from the object side to the image side. The first lens L1 has a negative optical power, and its object side surface S1 is a convex surface, and the image side surface S2 is a concave surface. The second lens L2 has a negative optical power, and its object side surface S3 is a concave surface, and the image side surface S4 is also a concave surface. The third lens L3 has a positive optical power, and its object side surface S5 is a convex surface, and the image side surface S6 is also a convex surface. Among them, the rear lens group includes a fourth lens L4, a fifth lens L5 and a sixth lens L6 from the object side to the image side. The fourth lens L4 has a positive optical power, and its object side surface S8 is a convex surface, and the image side surface S9 is also a convex surface. The fifth lens L5 has a negative focal power, and its object side surface S10 is concave, and its image side surface S11 is also concave. The sixth lens L6 has a positive focal power, and its object side surface S12 is convex, and its image side surface S13 is also convex. The lens also includes a filter I8, which is arranged between the sixth lens L6 and the image plane.

[0043] Specifically, the first lens L1 and the third lens L3 are both glass spherical lenses, and the second lens L2, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all plastic aspherical lenses.

[0044] Table 2 (a) shows the surface type, curvature radius, thickness and material of each lens of the ultra-wide-angle vehicle-mounted lens of Example 2. The units of the curvature radius and thickness are both millimeters (mm).

[0045] The design parameters of the lens of this embodiment 2 are specifically referred to the following table:

[0046] Table 2(a)

[0047]

[0048]

[0049] Table 2(b)

[0050]

[0051] In this embodiment 2, the specific parameters of the lens are shown in the following table:

[0052] Table 2(c)

[0053]

[0054] According to Table 2(a), Table 2(b) and Figure 4 Structural features of the optical system shown: The lens shown in Example 2 has the characteristics of large aperture and small size.

[0055] According to Table 2(c) and Figure 5 The distortion curve of the optical system shown, Figure 6 The MTF curve of the optical system shown shows that the lens shown in Example 2 can achieve good imaging.

Claims

1. An ultra-wide-angle vehicle-mounted lens, characterized in that: It successively includes a front lens group with positive optical power, a diaphragm, and a rear lens group with positive optical power along the optical axis from the object side to the image side; the front lens group successively includes a first lens, a second lens, and a third lens from the object side to the image side; wherein, the optical power of the first lens is negative, its object side is convex, and its image side is concave; the optical power of the second lens is negative, and both its object side and image side are concave; the optical power of the third lens is positive, and both its object side and image side are convex; the rear lens group successively includes a fourth lens, a fifth lens, and a sixth lens from the object side to the image side; wherein, the optical power of the fourth lens is positive, and both its object side and image side are convex; the optical power of the fifth lens is negative, and both its object side and image side are concave; the optical power of the sixth lens is positive, and both its object side and image side are convex; Both the first lens and the third lens are glass spherical lenses, the second lens, the fourth lens, the fifth lens, and the sixth lens are all plastic aspherical lenses, and the lens satisfies the conditional formula: 0.8 < EFLF / EFLB < 2.0; wherein, EFLF is the focal length of the front lens group of the optical system, and EFLB is the focal length of the rear lens group of the optical system; The first lens satisfies the following conditional formula: 1.8 < ∣D1 / f1∣ < 2.2; wherein, D1 is the effective aperture of the object side of the first lens, and f1 is the effective focal length of the first lens.

2. The ultra-wide-angle vehicle-mounted lens according to claim 1, characterized in that: The refractive index and dispersion coefficient of the first lens and the third lens respectively satisfy the following conditions: nd1 > 1.8, vd1 < 46.5, nd3 > 1.8, vd3 < 41.5; wherein, nd1 is the refractive index of the first lens, vd1 is the dispersion coefficient of the first lens, nd3 is the refractive index of the third lens, and vd3 is the dispersion coefficient of the third lens.

3. The ultra-wide-angle vehicle-mounted lens according to claim 1, characterized in that: The lens satisfies the following conditional formula: FOV > 180°; wherein, FOV is the total field of view angle of the lens.

4. The ultra-wide-angle vehicle-mounted lens according to claim 1, characterized in that: The lens satisfies the following conditional formula: 8.6 < TTL / F < 8.7; wherein, TTL is the total length of the lens, and F is the total focal length of the lens.

5. The ultra-wide-angle vehicle-mounted lens according to claim 1, characterized in that: The lens satisfies the following conditional formula: 0.2 < d6 / TTL < 0.25; wherein, d6 is the distance from the image side of the sixth lens to the imaging plane on the optical axis, and TTL is the total length of the lens.

6. The ultra-wide-angle vehicle-mounted lens according to claim 1, characterized in that: The lens satisfies the following conditional formula: 0.26 < (R7 + R9) / (R7 - R9) < 0.35; wherein, R7 is the curvature radius of the object side of the fourth lens, and R9 is the curvature radius of the object side of the fifth lens.

7. The ultra-wide-angle vehicle-mounted lens according to claim 1, characterized in that: The lens satisfies the following conditional formula: 2.5 < ∣f4 / f5∣ < 2.7; wherein, f4 is the effective focal length of the fourth lens, and f5 is the effective focal length of the fifth lens.

8. The ultra-wide-angle vehicle-mounted lens according to claim 1, characterized in that: The second lens, the fourth lens, the fifth lens, and the sixth lens satisfy the aspherical lens formula, and the aspherical coefficients satisfy the following equation: Z=cy 2 / [1+{1-(1+k)c 2 y 2 } 1 / 2 ]+A4y 4 +A6y 6 +A8y 8 +A10y 10 +A12y 12 +A14y 14 +A16y 16 Among them, Z is the aspheric surface vector height, c is the aspheric surface paraxial curvature, y is the lens aperture, k is the cone coefficient, A4 is the 4th aspheric surface coefficient, A6 is the 6th aspheric surface coefficient, A8 is the 8th aspheric surface coefficient, A10 is the 10th aspheric surface coefficient, A12 is the 12th aspheric surface coefficient, A14 is the 14th aspheric surface coefficient, and A16 is the 16th aspheric surface coefficient.

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