A wide-angle lens suitable for a drone

Abstract

The present application relates to a kind of wide-angle lens suitable for unmanned aerial vehicle, the optical system of the lens is made of first lens, second lens, third lens, diaphragm, fourth lens, fifth lens and sixth lens, first lens is meniscus concave negative lens, second lens is meniscus concave negative lens, third lens is double convex positive lens, fourth lens is double convex positive lens, fifth lens is meniscus concave negative lens, sixth lens is double convex positive lens, fourth lens and fifth lens constitute cemented lens, first lens and third lens are glass spherical lens, second lens, fourth lens, fifth lens and sixth lens are plastic aspherical lens. Two glass spherical lenses are used with four plastic aspherical lenses, compared with all-glass system, the system has lighter mass, compared with all-plastic system, the optical performance has stronger stability, while adapting to the environment, the cost is reduced;The imaging angle of object is greater than 130 degrees.

Description

Technical Field

[0001] This invention belongs to the field of lens technology, and in particular relates to a wide-angle lens suitable for drones. Background Technology

[0002] Due to its advantages such as mobility, speed, and economy, unmanned aerial vehicle (UAV) remote sensing has been widely applied in many fields of scientific research and civilian use. In recent years, with the continuous deepening of UAV aerial photography technology in various fields, people have become increasingly demanding in terms of the payload of UAVs. While meeting the requirements of wide field of view and high-resolution real-time imaging, the optical system also needs to be compact, lightweight, and small in size. Summary of the Invention

[0003] The present invention addresses the problems existing in the prior art. Specifically, the technical problem to be solved by the present invention is to provide a wide-angle lens suitable for drones, which is reasonably designed and achieves clear imaging at a wide angle of 130° while having a small size and high environmental stability.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a wide-angle lens suitable for drones, wherein the optical system of the lens consists of a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from left to right along the incident light path. The first lens is a meniscus negative lens, the second lens is a meniscus 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 fourth and fifth lenses form a cemented lens. The first and third lenses are glass spherical lenses, and the second, fourth, fifth, and sixth lenses are all plastic aspherical lenses.

[0005] Furthermore, the object-side surface of the first lens is convex, and the image-side surface is concave; the object-side surface of the second lens is concave, and the image-side surface is convex; the object-side surface of the third lens is convex, and the image-side surface is convex; the object-side surface of the fourth lens is convex, and the image-side surface is convex; the object-side surface of the fifth lens is concave, and the image-side surface is convex; and the object-side surface of the sixth lens is convex, and the image-side surface is convex.

[0006] Furthermore, the on-axis distances between the lenses satisfy the following relationships: the air gap between the first and second lenses is 3.0–3.5 mm; the air gap between the second and third lenses 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; the fourth and fifth lenses are a cemented lens group with an air gap of 0 mm; and the air gap between the fifth and sixth lenses is 0.5–1.0 mm.

[0007] Furthermore, the focal length of the optical system is f The focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are respectively f 1 , f 2 , f 3 , f 4 , f 5 , f 6 ,in f 1 , f 2 , f 3 , f 4 , f 5 , f 6 and f Meets the following ratio: -2.0 < f 1 / f <-1.0, -5.0< f 2 / f <-4.0, 1.0< f 3 / f <2.0, 1.0< f 4 / f <2.0, -2.0< f 5 / f <-1.0, 4.0< f 6 / f <5.0.

[0008] Furthermore, the first lens satisfies the relation: 1.6 ≤ N d ≤1.9, V d ≤50.0; The second lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The third lens satisfies the relationship: 1.6≤ N d ≤1.9, V d ≤50.0; The fourth lens satisfies the relationship: 1.5≤ Nd ≤1.8, V d ≥50.0; The fifth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; of which N d For refractive index, V d Let be Abbe's constant.

[0009] Furthermore, the equations for the aspherical curves of the second, fourth, fifth, and sixth lenses are as follows: Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of r; 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 all higher-order coefficients. Furthermore, the total optical length TTL of the optical system satisfies the following relationship with the focal length f: TTL / f ≤ 6.1.

[0010] Furthermore, the F-number of the optical system is ≤1.6.

[0011] Furthermore, the image height H of the optical system and the focal length f of the optical system satisfy the following condition: H / f≤1.1.

[0012] Furthermore, the right side of the sixth lens is provided with a first equivalent glass plate and a second equivalent glass plate arranged sequentially from left to right.

[0013] Compared with existing technologies, the present invention has the following advantages: The present invention is reasonably designed, using two glass spherical lenses in combination with four plastic aspherical lenses, which has a lighter system weight compared to all-glass systems and stronger optical performance stability compared to all-plastic systems, while reducing costs while adapting to the environment; the imaging angle of the object is greater than 130 degrees, and it has the advantages of high imaging clarity, large light transmission diameter, low tolerance sensitivity and good high and low temperature stability, while enabling more comprehensive monitoring of the target. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the optical structure according to an embodiment of the present invention; Figure 2 This is an axial chromatic aberration diagram of the entire working band of this invention. Figure 3This is a transverse chromatic aberration diagram of the entire working band of this invention. Figure 4 This is a field curvature distortion diagram of the entire working band according to an embodiment of the present invention.

[0015] In the picture: STO - Aperture stop; L1 - First lens; L2 - Second lens; L3 - Third lens; L4 - Fourth lens; L5 - Fifth lens; L6 - Sixth lens; L7 - First equivalent glass plate; L8 - Second equivalent glass plate; IMA - Imaging surface. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0018] like Figure 1 As shown, this invention provides a wide-angle lens suitable for drones. The optical system of the lens consists of a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from left to right along the incident light path. Without considering the curvature caused by aspherical coefficients, the first lens is a meniscus negative lens with a convex object-side surface and a concave image-side surface; the second lens is a meniscus negative lens with a concave object-side surface and a convex image-side surface; the third lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; the fourth lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface; the fifth lens is a meniscus negative lens with a concave object-side surface and a convex image-side surface; and the sixth lens is a biconvex positive lens with a convex object-side surface and a convex image-side surface. The fourth and fifth lenses form a cemented lens, the first and third lenses are glass spherical lenses, and the second, fourth, fifth, and sixth lenses are all plastic aspherical lenses. The optical structure employs two glass lenses paired with four plastic aspherical lenses, fully leveraging the aberration correction advantages of aspherical lenses to achieve high-definition imaging while maintaining a smaller lens outer diameter and shorter overall optical length, ensuring lens miniaturization. Compared to all-glass systems, the hybrid glass-plastic system is lighter, while compared to all-plastic systems, it offers stronger optical performance stability, and reduces costs while being more adaptable to different environments.

[0019] In this embodiment, the first and third lenses are spherical lenses with negative optical power, which adjust large-angle light while reducing optical system distortion. This reasonable lens combination enables the optical system to achieve a small size, 130° ultra-wide angle, large aperture, day / night confocal focus, and low temperature drift design. Simultaneously, it provides good correction for on-axis and off-axis aberrations, resulting in good image quality. Figures 2 to 4 As shown.

[0020] In this embodiment, the on-axis distances between the lenses satisfy the following relationships: the air gap between the first lens and the second lens is 3.0 to 3.5 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 stop is 0.1 to 0.5 mm; the air gap between the aperture stop and the fourth lens is 0.1 to 0.5 mm; the fourth lens and the fifth lens are a cemented lens group with an air gap of 0; and the air gap between the fifth lens and the sixth lens is 0.5 to 1.0 mm.

[0021] In this embodiment, the focal length of the optical system is f The focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are respectively f 1 , f 2 , f 3 , f 4 , f 5 , f 6 ,in f 1 , f 2 , f 3 , f 4 , f 5 , f 6 and f Meets the following ratio: -2.0 < f 1 / f <-1.0, -5.0< f 2 / f <-4.0, 1.0< f 3 / f <2.0, 1.0< f 4 / f <2.0, -2.0< f5 / f <-1.0, 4.0< f 6 / f <5.0.

[0022] 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: 1.5≤ N d ≤1.8, V d ≥50.0; The third lens satisfies the relationship: 1.6≤ N d ≤1.9, 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: 1.5≤ N d ≤1.8, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; of which N d For refractive index, V d Let be Abbe's constant.

[0023] In this embodiment, the equations for the aspherical curves of the second lens, the fourth lens, the fifth lens, and the sixth lens are as follows: Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of r; 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 all higher-order coefficients. Furthermore, the total optical length TTL of the optical system satisfies the following relationship with the focal length f: TTL / f ≤ 6.1.

[0024] In this embodiment, the F-number of the optical system is ≤1.6.

[0025] In this embodiment, the image height H of the optical system and the focal length f of the optical system satisfy the following condition: H / f≤1.1.

[0026] In this embodiment, a first equivalent glass plate and a second equivalent glass plate are arranged sequentially from left to right on the right side of the sixth lens.

[0027] In this embodiment, the technical specifications achieved by the lens's optical system are as follows: (1) Effective focal length: 3.0≤EFFL≤4.0mm; (2) Aperture F≤1.6; (3) Field of view: 2w ≥ 130°; (4) Operating band: Visible light band.

[0028] To achieve the above technical specifications, the specific design of the optical system in this embodiment is shown in the table below: .

[0029] The aspherical coefficients of the aspherical lenses in the optical system of this embodiment are shown in the table below: The optical system in this embodiment achieves miniaturization of the lens group by rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis distance between each lens, while meeting the requirements of 130° ultra-wide-angle imaging performance.

[0030] The advantages of this invention are: 1. This lens has an imaging angle of more than 130 degrees and features high imaging clarity, large aperture, low tolerance sensitivity and good high and low temperature stability, while also enabling more comprehensive monitoring of the target. 2. By rationally matching the various optical lenses, the system structure is compact and reasonable, reducing the overall size, making it easy to assemble, with low tolerance sensitivity, and more suitable for large-scale high-yield production; 3. It uses two glass spherical lenses in combination with four plastic aspherical lenses, which has a lighter system weight compared to the all-glass system and stronger optical performance stability compared to the all-plastic system, while reducing costs while adapting to the environment. 4. The chromatic aberration along each axis, the transverse chromatic aberration, and higher-order chromatic aberrations have been corrected to ensure that the imaging system can maintain high imaging quality even at large angles.

[0031] If this invention discloses or relates to components or structural parts that are fixedly connected to each other, then, unless otherwise stated, a fixed connection can be understood as: a fixed connection that can be detached (e.g., using bolts or screws), or a fixed connection that cannot be detached (e.g., riveting, welding). Of course, a fixed connection can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0032] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0033] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A wide-angle lens suitable for drones, characterized in that: The optical system of the lens consists of a first lens, a second lens, a third lens, an aperture stop, a fourth lens, a fifth lens, and a sixth lens arranged sequentially from left to right along the incident light path. The first lens is a meniscus negative lens, the second lens is a meniscus 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 fourth and fifth lenses form a cemented lens. The first and third lenses are glass spherical lenses, and the second, fourth, fifth, and sixth lenses are all plastic aspherical lenses. The on-axis distances between the lenses satisfy the following relationships: the air gap between the first and second lenses is 3.0–3.5 mm; the air gap between the second and third lenses 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; the fourth and fifth lenses are a cemented lens group with an air gap of 0 mm; the air gap between the fifth and sixth lenses is 0.5–1.0 mm. The focal length of the optical system is f The focal lengths of the first lens, second lens, third lens, fourth lens, fifth lens, and sixth lens are respectively f 1 , f 2 , f 3 , f 4 , f 5 , f 6 ,in f 1 , f 2 , f 3 , f 4 , f 5 , f 6 and f Meets the following ratio: -2.0 < f 1 / f <-1.0, -5.0< f 2 / f <-4.0, 1.0< f 3 / f <2.0, 1.0< f 4 / f <2.0, -2.0< f 5 / f <-1.0, 4.0< f 6 / f <5.

0.

2. A wide-angle lens suitable for drones according to claim 1, characterized in that: The first lens has a convex object-side surface and a concave image-side surface; the second lens has a concave object-side surface and a convex image-side surface; the third lens has a convex object-side surface and a convex image-side surface; the fourth lens has a convex object-side surface and a convex image-side surface; the fifth lens has a concave object-side surface and a convex image-side surface; and the sixth lens has a convex object-side surface and a convex image-side surface.

3. A wide-angle lens suitable for drones according to claim 1, characterized in that: The first lens satisfies the relation: 1.6 ≤ N d ≤1.9, V d ≤50.0; The second lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; The third lens satisfies the relationship: 1.6≤ N d ≤1.9, 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: 1.5≤ N d ≤1.8, V d ≤50.0; The sixth lens satisfies the relationship: 1.5≤ N d ≤1.8, V d ≥50.0; of which N d For refractive index, V d Let be Abbe's constant.

4. A wide-angle lens suitable for drones according to claim 1, characterized in that: The equations for the aspherical curves of the second, fourth, fifth, and sixth lenses are as follows: Where Z is the distance from the vertex of the aspherical surface to the optical axis at a height of r; 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 all higher-order coefficients.

5. A wide-angle lens suitable for drones according to claim 1, characterized in that: The total optical length (TTL) of an optical system and the focal length (f) of the optical system satisfy the following condition: TTL / f ≤ 6.

1.

6. A wide-angle lens suitable for drones according to claim 1, characterized in that: The F-number of the optical system is ≤1.

6.

7. A wide-angle lens suitable for drones 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 the following relationship: H / f≤1.

1.

8. A wide-angle lens suitable for drones according to claim 1, characterized in that: The right side of the sixth lens is provided with a first equivalent glass plate and a second equivalent glass plate arranged from left to right.

Images