Large-aperture day-and-night wide-angle lens

Abstract

The present application relates to a kind of large aperture day and night wide-angle lens, the optical system of the lens includes first lens, second lens, third lens, diaphragm, fourth lens, fifth lens and sixth lens in turn from left to right along the light path of light incidence, first lens is negative meniscus, second lens is double concave negative lens, third lens is double convex positive lens, fourth lens is double convex positive lens, fifth lens is negative meniscus, and sixth lens is double convex positive lens;The first lens, second lens and sixth lens are glass spherical lens;Second lens, fourth lens and fifth lens are plastic aspherical lens.The present application adopts the design of three glass lenses and three plastic lenses, and the shape and optical power of lens are reasonably matched, while meeting the optical performance of 4K high resolution, good environmental stability and the like, meeting the needs of large aperture, large target surface, day and night focusing and the like, and the whole lens is more compact.

Description

Technical field:

[0001] The invention relates to a large-aperture wide-angle lens for day and night use. Background technology:

[0002] With the continuous advancement of science and technology, optical lenses are being used in various fields, including intelligent driving, safe cities, smartphones, smart homes, and machine vision. Diverse application scenarios have led to the development of a wide variety of optical lenses. Wide-angle lenses, with their shorter focal length and wider field of view, can capture a greater degree of scene information when photographing objects. They are commonly used in automotive, security surveillance, machine vision, and other fields.

[0003] Currently, ultra-high-definition optical lenses used in security and automotive applications generally have the following shortcomings: existing wide-angle lenses usually have too long TTL and large dimensions. In addition, while achieving 4K high-definition imaging, it is difficult for existing wide-angle lenses to take into account optical properties such as large aperture, large target area, and day and night confocality. Summary of the invention:

[0004] The present invention aims to improve the problems existing in the above-mentioned prior art, that is, the technical problem to be solved by the present invention is to provide a large-aperture wide-angle lens for day and night use.

[0005] To achieve the above-mentioned object, the present invention adopts a technical solution: a large-aperture wide-angle lens for day and night use, wherein the optical system of the lens includes 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 light, wherein the first lens is a negative meniscus lens, the second lens is a biconcave negative lens, the third lens is a biconvex positive lens, the fourth lens is a biconvex positive lens, the fifth lens is a negative meniscus lens, and the sixth lens is a biconvex positive lens; the first lens, the third lens, and the sixth lens are all glass spherical lenses; and the second lens, the fourth lens, and the fifth lens are all plastic aspherical lenses.

[0006] Furthermore, the object-side surface of the first lens is convex, and the image-side surface is concave; the object-side surface of the fifth lens near the optical axis is convex, and the image-side surface near the optical axis is concave.

[0007] Furthermore, the air gap between the first lens and the second lens is 1.87 to 3.0 mm; the air gap between the second lens and the third lens is 0.5 to 1.1 mm; the air gap between the third lens and the fourth lens is 0.35 to 1.0 mm; the air gap between the fourth lens and the fifth lens is 0.01 to 0.1 mm; and the air gap between the fifth lens and the sixth lens is 0.1 to 0.55 mm.

[0008] 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, and the sixth lens are f1, f2, f3, f4, f5, and f6, respectively, where f1, f2, f3, f4, f5, and f6 satisfy the following ratios to f: -3.0<f1 / f<-1.0, -3.0<f2 / f<-1.0, 5.5<f3 / f<6.5, 1.0<f4 / f<3.0, -3.0<f5 / f<-1.0, and 1.0<f6 / f<3.0.

[0009] Furthermore, 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.

[0010] Furthermore, the total optical length TTL of the optical system and the focal length f of the optical system satisfy: TTL / f≤8.0.

[0011] Furthermore, the F number of the optical system is ≤1.8.

[0012] Furthermore, the image height H of the optical system and the focal length f of the optical system satisfy: H / f≥2.4.

[0013] Furthermore, the aspheric curve equations of the second lens, the fourth lens, and the fifth lens are expressed as follows:

[0014]

[0015] 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.

[0016] Compared with the existing technology, the present invention has the following effects: the present invention adopts a design that mixes three glass lenses and three plastic lenses, and reasonably matches the lens shape and optical focal length. While meeting the optical performance such as 4K high resolution and good environmental stability, it also meets the requirements of large aperture, large target surface, day and night confocality, and the overall lens is more compact. Description of the drawings:

[0017] Figure 1 is a schematic diagram of the optical structure of an embodiment of the present invention;

[0018] Figure 2 This is a full-band axial chromatic aberration diagram of an embodiment of the present invention;

[0019] Figure 3 This is a vertical axis chromatic aberration diagram for the entire working band of an embodiment of the present invention;

[0020] Figure 4 This is a field curvature distortion diagram for the entire working band of an embodiment of the present invention.

[0021] In the picture:

[0022] L1-first lens; L2-second lens; L3-third lens; L4-fourth lens; L5-fifth lens; L6-sixth lens; L7-equivalent glass plate; IMA-imaging surface; STO-aperture. Specific implementation method:

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, a large-aperture wide-angle lens for day and night use according to the present invention comprises an optical system comprising, arranged in order from left to right along an incident light path, a first lens L1, a second lens L2, a third lens L3, an aperture, a fourth lens L4, a fifth lens L5, and a sixth lens L6. The first lens L1 is a negative meniscus lens, with the object-side surface of the first lens L1 being convex and the image-side surface being concave. The second lens L2 is a biconcave negative lens, the third lens L3 is a biconvex positive lens, the fourth lens L4 is a biconvex positive lens, and the fifth lens L5 is a negative meniscus lens, with the object-side surface of the fifth lens L5 near the optical axis being convex and the image-side surface near the optical axis being concave. The sixth lens L6 is a biconvex positive lens. The first lens L1, the third lens L3, and the sixth lens L6 are all glass spherical lenses. The second lens L2, the fourth lens L4, and the fifth lens L5 are all plastic aspherical lenses.

[0025] In this embodiment, the air gap between the first lens L1 and the second lens L2 is 1.87-3.0 mm; the air gap between the second lens L2 and the third lens L3 is 0.5-1.1 mm; the air gap between the third lens L3 and the fourth lens L4 is 0.35-1.0 mm; the air gap between the fourth lens L4 and the fifth lens L5 is 0.01-0.1 mm; and the air gap between the fifth lens L5 and the sixth lens L6 is 0.1-0.55 mm.

[0026] In this embodiment, the focal length of the optical system is f, and the focal lengths of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are f1, f2, f3, f4, f5, and f6, respectively. Where f1, f2, f3, f4, f5, and f6 satisfy the following ratio with f: -3.0 <f1 / f<-1.0,-3.0<f2 / f<-1.0,5.5<f3 / f<6.5,1.0<f4 / f<3.0,-3.0<f5 / f<-1.0,1.0<f6 / f<3.0。

[0027] In this embodiment, the first lens L1 satisfies the relationship: N d ≥1.5, V d ≥50.0; the second lens L2 satisfies the relationship: N d ≥1.5, V d ≥50.0; the third lens L3 satisfies the relationship: N d ≥1.5, V d ≤50.0; the fourth lens L4 satisfies the relationship: N d ≥1.5, V d ≥50.0; the fifth lens L5 satisfies the relationship: N d ≥1.5, V d ≤50.0; the sixth lens L6 satisfies the relationship: N d ≥1.5, V d ≥50.0; where N d is the refractive index, V d is the Abbe constant.

[0028] In this embodiment, the total optical length TTL of the optical system and the focal length f of the optical system satisfy the following relationship: TTL / f≤8.0.

[0029] In this embodiment, the F number of the optical system is ≤1.8.

[0030] In this embodiment, the image height H of the optical system and the focal length f of the optical system satisfy the following relationship: H / f≥2.4.

[0031] In this embodiment, the aspheric curve equations of the second lens L2, the fourth lens L4, and the fifth lens L5 are expressed as follows:

[0032]

[0033] 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.

[0034] In this embodiment, the aspheric coefficients of the aspheric lenses of the optical system are as follows:

[0035]

[0036] In this embodiment, Figures 2 to 4 As shown in the figure, the lens reasonably corrects the on-axis and off-axis aberrations to achieve 4K image quality.

[0037] In this embodiment, the technical indicators achieved by the optical system are as follows:

[0038] (1) Focal length: 2.0 ≤ EFFL ≤ 4.0 mm; (2) Aperture F ≤ 1.8; (3) Field of view: 2w ≥ 140°; (4) Operating wavelength: visible light band and 850 nm band.

[0039] To achieve the above technical indicators, the specific design of the optical system of this embodiment is shown in the following table:

[0040]

[0041]

[0042] In this embodiment, the optical system realizes a large aperture, a small size, and a design for both day and night use, while also performing good corrections for on-axis and off-axis aberrations.

[0043] The advantages of the present invention are:

[0044] 1. The 3G3P optical structure, which combines three glass spherical lenses with three plastic aspherical lenses, rationally matches lens shape and optical power. This allows the lens to meet 4K ultra-high-definition imaging requirements while maintaining a relative aperture of 1 / 1.8, a smaller lens outer diameter, and a shorter overall optical length, ensuring miniaturization.

[0045] 2. The infrared band and the visible light band have a small back focus difference, that is, the infrared defocus is small, and confocality can be achieved day and night;

[0046] 3. Better correct the chromatic aberration of the purple band and eliminate the purple fringing effect;

[0047] 4. While matching the 1 / 2.5-inch large target surface, it ensures a relative illumination of more than 50%;

[0048] 5. While meeting various optical performance indicators, professional optical resin materials are used, and based on the relationship between the material's refractive index and temperature, it is ensured that the back focus offset is minimal at an operating temperature of -40°C to 80°C, and ultra-high-definition imaging can still be achieved.

[0049] If the present invention 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, 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 integrated molding using a casting process) (except where it is obviously impossible to use an integrated molding process).

[0050] In addition, unless otherwise stated, the terms used in any technical solution disclosed in the present invention to express positional relationships or shapes include states or shapes that are approximate, similar, or close thereto.

[0051] Any component provided by the present invention may be assembled from multiple separate components, or may be a separate component manufactured by an integral molding process.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to 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 solutions of the present invention. They should all be included in the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A large-aperture wide-angle lens for day and night use, characterized by: The optical system of the lens includes a first lens, a second lens, a third lens, an aperture, a fourth lens, a fifth lens and a sixth lens, which are arranged in sequence from left to right along the incident light path of the light. The first lens is a meniscus negative lens, the second lens is a biconcave negative lens, the third lens is a biconvex 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 first, third and sixth lenses are all glass spherical lenses. The second, fourth and fifth lenses are all plastic aspherical lenses. The air gap between the first and second lenses is 1.87 to 3.0 mm; the air gap between the second and third lenses is 0.5 to 1.1 mm; the air gap between the third and fourth lenses is 0.35 to 1.0 mm; the air gap between the fourth and fifth lenses is 0.01 to 0.1 mm; and the air gap between the fifth and sixth lenses is 0.1 to 0.55 mm.

2. The large-aperture wide-angle lens for day and night use according to claim 1, characterized in that: The object-side surface of the first lens is convex, and the image-side surface is concave; the object-side surface of the fifth lens near the optical axis is convex, and the image-side surface near the optical axis is concave.

3. The large-aperture wide-angle lens for day and night use according to claim 1, characterized in that: The focal length of the optical system is f, and the focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are f1, f2, f3, f4, f5, and f6 respectively, where f1, f2, f3, f4, f5, and f6 satisfy the following ratio with f: -3.0 <f1 / f<-1.0,-3.0<f2 / f<-1.0,5.5<f3 / f<6.5,1.0<f4 / f<3.0,-3.0<f5 / f<-1.0,1.0<f6 / f<3.0。 4. The large-aperture wide-angle lens for day and night use 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.

5. The large-aperture wide-angle lens for day and night use 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≤8.

0.

6. The large-aperture wide-angle lens for day and night use according to claim 1, characterized in that: The F number of the optical system is ≤1.

8.

7. The large-aperture wide-angle lens for day and night use 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≥2.

4.

8. The large-aperture wide-angle lens for day and night use according to claim 1, characterized in that: The aspheric curve equations of the second lens, the fourth lens, and the fifth lens are: 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.

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