Ultra-wide-angle optical lens and imaging method thereof

Abstract

The present invention relates to an ultra-wide-angle optical lens, comprising a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens arranged in sequence from left to right along the incident light path of the light; wherein the first lens is a meniscus negative lens, the second lens is a double concave negative lens, the third lens is a meniscus positive lens, the fourth lens is a double convex positive lens, the fifth lens is a meniscus negative lens, and the sixth lens is a double convex positive lens. In terms of optical performance, a multi-piece aspherical lens design is adopted, the imaging quality is excellent, and the axial chromatic aberration and lateral chromatic aberration of the entire optical system are well corrected; the full field of view can reach 200°, which can provide all-round stable monitoring; the maximum aperture can reach F1.6, and the overall optical performance has been further improved.

Description

Technical Field

[0001] The invention relates to an ultra-wide-angle optical lens and an imaging method thereof. Background Art

[0002] Today, the demand for surround view lenses is increasing. According to statistics, the market size of surround view ADAS cameras in China alone has reached millions of dollars in 2021, and will continue to grow at a relatively fast pace in the future. However, as the total market volume continues to increase, news of related ADAS products often come out about inaccurate recognition or even errors leading to traffic accidents, which makes the public always have a certain degree of doubt about the stability of related lenses. Summary of the invention

[0003] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an ultra-wide-angle optical lens and an imaging method thereof.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: an ultra-wide-angle optical lens, comprising a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens arranged in sequence from left to right along the incident light path of the light; wherein the first lens is a meniscus negative lens, the second lens is a double concave negative lens, the third lens is a meniscus positive lens, the fourth lens is a double convex positive lens, the fifth lens is a meniscus negative lens, and the sixth lens is a double convex positive lens.

[0005] Preferably, the first lens and the fourth lens are glass lenses, and the second, third, fifth and sixth lenses are plastic lenses.

[0006] Preferably, the fifth lens and the sixth lens are glued together to form a glued positive lens group.

[0007] Preferably, the focal length of the optical system is set to f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the cemented positive lens group are respectively f 1 、f 2 、f 3 、f 4 , fc, where f 1 、f 2 、f 3 、f 4 , fc and f satisfy the following ratio: -5.5 <f 1 / f<-4.5,-2.9 <f 2 / f<-1.5,4.9 <f 3 / f<8.1,3.0 <f 4 / f<3.7,6.0 <fc / f<16.0。

[0008] Preferably, the first lens satisfies the relationship: N d ≥1.5, Vd ≤50.0; the second lens satisfies the relationship: N d ≥1.5, V d ≥50.0; the third lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the fourth lens satisfies the relationship: N d ≥1.5, V d ≥50.0; the fifth lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the sixth lens satisfies the relationship: N d ≥1.5, V d ≥50.0; where N d is the refractive index, V d is the Abbe constant.

[0009] Preferably, the second lens, the third lens, the fifth lens and the sixth lens are 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 h 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] Preferably, the total optical length TTL of the optical system and the focal length f of the optical system satisfy the following relationship: 10.5≤TTL / f≤14.0.

[0013] Preferably, the F number of the optical system is ≤2.0.

[0014] Preferably, the half image height ImaH of the optical system and the focal length f of the optical system satisfy: 1.72≤ImaH / f.

[0015] An imaging method of an ultra-wide-angle optical lens is performed according to the following steps: light rays are imaged after passing through a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, and a sixth lens from left to right in sequence.

[0016] Compared with the prior art, the present invention has the following beneficial effects: in terms of optical performance, it adopts a multi-piece aspherical lens design, has excellent imaging quality, and the axial chromatic aberration and lateral chromatic aberration of the entire optical system are well corrected; the full field of view can reach 200°, which can provide all-round stable monitoring; the maximum aperture can reach F1.6, and the overall optical performance is further improved.

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the optical structure of the first embodiment of the present invention;

[0019] Figure 2 This is a working band MTF performance diagram of the first embodiment of the present invention;

[0020] Figure 3 axial chromatic aberration, field curvature, and distortion diagram of the working band of the first embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of the optical structure of the second embodiment of the present invention;

[0022] Figure 5 This is a working band MTF performance diagram of the second embodiment of the present invention;

[0023] Figure 6 This is a diagram of axial chromatic aberration, field curvature, and distortion in the working band of the second embodiment of the present invention.

[0024] In the figure: L1-first lens; L2-second lens; L3-third lens; STO-aperture; L4-fourth lens; L5-fifth lens; L6-sixth lens; L7-equivalent glass plate; IMA-imaging surface. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0027] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0028] like Figures 1 to 6 As shown, this embodiment provides an ultra-wide-angle optical lens, including a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens arranged in sequence from left to right along the incident light path of the light; wherein the first lens is a meniscus negative lens, the second lens is a double concave negative lens, the third lens is a meniscus positive lens, the fourth lens is a double convex positive lens, the fifth lens is a meniscus negative lens, and the sixth lens is a double convex positive lens.

[0029] In the embodiment of the present invention, the first lens and the fourth lens are glass lenses, and the second, third, fifth and sixth lenses are plastic lenses.

[0030] In an embodiment of the present invention, the fifth lens and the sixth lens are glued together to form a glued positive lens group.

[0031] In the embodiment of the present invention, the focal length of the optical system is set to be f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the cemented positive lens group are respectively f 1 、f 2 、f 3 、f 4 , fc, where f 1 、f 2 、f 3 、f 4 , fc and f satisfy the following ratio: -5.5 <f 1 / f<-4.5,-2.9 <f 2 / f<-1.5,4.9 <f 3 / f<8.1,3.0 <f 4 / f<3.7,6.0 <fc / f<16.0。

[0032] In the embodiment of the present invention, the first lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the second lens satisfies the relationship: N d ≥1.5, V d ≥50.0; the third lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the fourth lens satisfies the relationship: N d ≥1.5, V d ≥50.0; the fifth lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the sixth lens satisfies the relationship: N d ≥1.5, V d ≥50.0; where N d is the refractive index, V dis the Abbe constant.

[0033] In the embodiment of the present invention, the second lens, the third lens, the fifth lens and the sixth lens are aspherical lenses, and the aspherical curve equation is expressed as:

[0034]

[0035] Where Z is the height of the aspheric surface from the vertex of the aspheric surface at a height of h 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.

[0036] In the embodiment of the present invention, the total optical length TTL of the optical system and the focal length f of the optical system satisfy the following relationship: 10.5≤TTL / f≤14.0.

[0037] In the embodiment of the present invention, the F number of the optical system is ≤2.0.

[0038] In the embodiment of the present invention, the half image height ImaH of the optical system and the focal length f of the optical system satisfy the following relationship: 1.72≤ImaH / f.

[0039] An imaging method of an ultra-wide-angle optical lens is performed according to the following steps: light rays are imaged after passing through a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens, and a sixth lens from left to right in sequence.

[0040] Specific implementation process:

[0041] Embodiment 1:

[0042] The technical indicators achieved by the optical system of this embodiment are as follows:

[0043] (1) Focal length: 1.47mm≤EFFL≤1.55mm; (2) Aperture F≤2.0.

[0044] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:

[0045]

[0046] The aspheric coefficients of the aspheric lenses of the optical system of this embodiment are as follows:

[0047]

[0048] Embodiment 2:

[0049] The technical indicators achieved by the optical system of this embodiment are as follows:

[0050] (1) Focal length: 1.04mm≤EFFL≤1.21mm; (2) Aperture F≤1.6.

[0051] To achieve the above design parameters, the specific design adopted by the optical system of this embodiment is shown in the following table:

[0052]

[0053] The aspheric coefficients of the aspheric lenses of the optical system of this embodiment are as follows:

[0054]

[0055] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content 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 according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. An ultra-wide-angle optical lens, characterized in that: The ultra-wide-angle optical lens is composed of six lenses, including a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens, and a sixth lens arranged in sequence from left to right along the light incident optical path; among them, the first lens is a meniscus negative lens, the second lens is a biconcave negative lens, the third lens is a meniscus positive lens, the fourth lens is a biconvex positive lens, the fifth lens is a meniscus negative lens, and the sixth lens is a biconvex positive lens; the fifth lens and the sixth lens are mutually cemented to form a cemented positive lens group; setting the focal length of the optical system as f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the cemented positive lens group are f1, f2, f3, f4, and fc respectively, where f1, f2, f3, f4, and fc satisfy the following ratios with f: -5.5 < f1 / f < -4.5, -2.9 < f2 / f < -1.5, 4.9 < f3 / f < 8.1, 3.0 < f4 / f < 3.7, 6.0 < fc / f < 16.0; the first lens and the fourth lens are glass lenses, and the second, third, fifth, and sixth lenses are plastic lenses.

2. The ultra-wide-angle optical lens according to claim 1, characterized in that: The first lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the second lens satisfies the relationship: N d ≥1.5, V d ≥50.0; the third lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the fourth lens satisfies the relationship: N d ≥1.5, V d ≥50.0; the fifth lens satisfies the relationship: N d ≥1.5, V d ≤50.0; the sixth lens satisfies the relationship: N d ≥1.5, V d ≥50.0; where N d is the refractive index, V d is the Abbe constant.

3. The ultra-wide-angle optical lens according to claim 1, characterized in that: The second lens, the third lens, the fifth lens, and the sixth lens are aspherical lenses, and the expression of the aspherical curve equation is: where Z is the sagitta height from the vertex of the aspherical surface when the aspherical surface is at a position with a height of h along the optical axis direction; c is the paraxial curvature of the aspherical surface; k is the conic constant; α1, α2, α3, α4, α5, α6, α7, and α8 are all high-order term coefficients.

4. The ultra-wide-angle optical lens 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: 10.5 ≤ TTL / f ≤ 14.

0.

5. The ultra-wide-angle optical lens according to claim 1, characterized in that: The F-number of the optical system ≤ 2.

0.

6. The ultra-wide-angle optical lens according to claim 1, characterized in that: The semi-image height ImaH of the optical system and the focal length f of the optical system satisfy: 1.72 ≤ ImaH / f.

7. An imaging method of an ultra-wide-angle optical lens according to any one of claims 1 to 6, characterized in that: It is carried out according to the following steps: The light sequentially passes through the first lens, the second lens, the third lens, the diaphragm, the fourth lens, the fifth lens, and the sixth lens from left to right and then forms an image.

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