An unmanned aerial vehicle imaging lens

Abstract

The application discloses an unmanned aerial vehicle imaging lens, which comprises, from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens and a fourteenth lens; the first lens is a meniscus positive refractive power lens, and the convex surface faces the object plane; the second lens is a meniscus negative refractive power lens, and the convex surface faces the object plane; and the third lens is a meniscus negative refractive power lens, and the convex surface faces the object plane; the technical scheme adopts a combination of fourteen lenses, and the refractive power, shape and material of each optical lens are reasonably matched and combined, so that the unmanned aerial vehicle imaging lens with the focal length of 6.6 mm, the wavelength of visible light, the field of view angle of 104 degrees and the aperture F of 2.8 on a 1-inch target surface can be obtained, the unmanned aerial vehicle imaging lens can realize infinite distance imaging, and the requirements of low distortion and achromatism are met.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and in particular to an imaging lens for unmanned aerial vehicles (UAVs). Background Technology

[0002] With the widespread application of drone aerial photography, users have increasingly higher requirements for the quality of aerial photography. High-quality imaging lenses are the development trend of the entire industry, and imaging lenses are constantly being innovated. The demand for different focal lengths of drone imaging lenses is increasing, but the existing focal lengths available are very limited, and the imaging quality is not high and the field of view is small. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a drone imaging lens that can achieve high imaging quality and infinity imaging at a focal length of 6.6mm, making it an ultra-wide-angle drone lens.

[0004] An imaging lens for a drone according to an embodiment of the present invention includes, in sequence from the object side to the image side: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, and a fourteenth lens; the first lens is a meniscus positive diopter lens with its convex surface facing the object surface; the second lens is a meniscus negative diopter lens with its convex surface facing the object surface; the third lens is a meniscus negative diopter lens with its convex surface facing the object surface; the fourth lens is a meniscus negative diopter lens with its convex surface facing the object surface; The convex surface faces the object plane; the fifth lens is a biconvex positive diopter lens, the sixth lens is a biconcave negative diopter lens, the seventh lens is a biconvex positive diopter lens, the eighth lens is a biconvex positive diopter lens, the ninth lens is a biconvex positive diopter lens, the tenth lens is a biconcave negative diopter lens; the eleventh lens is a meniscus positive diopter lens, with its convex surface facing the image plane; the twelfth lens is a meniscus negative diopter lens, with its convex surface facing the image plane; the thirteenth lens is a biconvex positive diopter lens; the fourteenth lens is a meniscus negative diopter lens, with its convex surface facing the image plane.

[0005] A drone imaging lens according to an embodiment of the present invention has at least the following beneficial effects:

[0006] This technical solution uses a combination of fourteen lenses. By rationally matching and combining the refractive power, shape, and material of each optical lens, the above configuration is conducive to ensuring a 1-inch target surface drone imaging lens with a focal length of 6.6mm, a wavelength of visible light, a field of view of 104°, and an aperture of F2.8. This lens can image at infinity and meets the requirements of low distortion and achromatic aberration.

[0007] According to some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the relational expression: 2 < f1 / f < 7; where f is the focal length of the imaging lens of the unmanned aerial vehicle, and f1 is the focal length of the first lens.

[0008] According to some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the relational expression: 2 < f1 / f8 < 5; where f1 is the focal length of the first lens, and f8 is the focal length of the eighth lens.

[0009] According to some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the relational expression: -2 < f3 / f < 0; where f is the focal length of the imaging lens of the unmanned aerial vehicle, and f3 is the focal length of the third lens.

[0010] According to some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the following relational expression:

[0011] 1.73 < n(L1) < 1.85;

[0012] 38 < V(L1) < 52;

[0013] where n(L1) is the refractive index of the first lens, and V(L1) is the Abbe number of the first lens.

[0014] According to some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the following relational expression:

[0015] 1.62 < n(L8) < 1.73;

[0016] 50 < V(L8) < 60;

[0017] where n(L8) is the refractive index of the eighth lens, and V(L8) is the Abbe number of the eighth lens.

[0018] According to some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the following relational expression:

[0019] 15 < V(L4) - V(L5) < 25;

[0020] -30 < V(L6) - V(L7) < -20;

[0021] -25 < V(L9) - V(L10) < -10;

[0022] 30 < V(L11) - V(L12) < 40;

[0023] 45 < V(L13) - V(L14) < 55;

[0024] Among them, V(L4), V(L5), V(L6), V(L7), V(L9), V(L10), V(L11), V(L12), V(L13), and V(L14) are the Abbe numbers of the fourth, fifth, sixth, seventh, ninth, tenth, eleventh, twelfth, thirteenth, and fourteenth lenses, respectively.

[0025] According to some embodiments of the present invention, the fourth lens and the fifth lens are a cemented lens group, the sixth lens and the seventh lens are a cemented lens group, the ninth lens and the tenth lens are a cemented lens group, the eleventh lens and the twelfth lens are a cemented lens group, and the thirteenth lens and the fourteenth lens are a cemented lens group.

[0026] According to some embodiments of the present invention, an aperture is provided between the seventh lens and the eighth lens.

[0027] According to some embodiments of the present invention, the focal length of the UAV imaging lens is F = 6.6 mm, and the aperture value is FNO = 2.8.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0030] Figure 1 This is a schematic diagram of the imaging lens structure of a drone according to an embodiment of the present invention;

[0031] Figure 2 This is an imaging optical path diagram of an unmanned aerial vehicle (UAV) imaging lens according to an embodiment of the present invention;

[0032] Figure 3 This is an MTF curve of an imaging lens for a drone according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of field curvature and distortion of an unmanned aerial vehicle (UAV) imaging lens according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the dot array of an imaging lens for a drone according to an embodiment of the present invention.

[0035] Icon labels:

[0036] Aperture STO, first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8, ninth lens L9, tenth lens L10, eleventh lens L11, twelfth lens L12, thirteenth lens L13, fourteenth lens L14. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0039] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or the order in which the indicated technical features are presented.

[0040] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0041] To address the issues of limited focal length options, low image quality, and narrow field of view in existing ultra-wide-angle drone lenses, this invention proposes an ultra-wide-angle drone lens with high image quality and infinity imaging at a focal length of 6.6mm. The specific solution is as follows:

[0042] Reference Figure 1 As shown, an embodiment of the UAV imaging lens of the present invention includes fourteen lenses arranged sequentially from the object side to the image side: a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, and a fourteenth lens L14. It should be understood that the lens of this embodiment only discloses the lenses that determine the imaging effect and does not include mounting structures such as lens barrels.

[0043] Among them, the first lens L1 is a meniscus lens with positive diopter, and its convex surface faces the object surface; the second lens L2 is a meniscus lens with negative diopter, and its convex surface faces the object surface; the third lens L3 is a meniscus lens with negative diopter, and its convex surface faces the object surface; the fourth lens L4 is a meniscus lens with negative diopter, and its convex surface faces the object surface; the fifth lens L5 is a biconvex lens with positive diopter, the sixth lens L6 is a biconcave lens with negative diopter, the seventh lens L7 is a biconvex lens with positive diopter, the eighth lens L8 is a biconvex lens with positive diopter, the ninth lens L9 is a biconvex lens with positive diopter, and the tenth lens L10 is a biconcave lens with negative diopter; the eleventh lens L11 is a meniscus lens with positive diopter, and its convex surface faces the image surface; the twelfth lens L12 is a meniscus lens with negative diopter, and its convex surface faces the image surface; the thirteenth lens L13 is a biconvex lens with positive diopter; the fourteenth lens L14 is a meniscus lens with negative diopter, and its convex surface faces the image surface. As Figure 2 shown, in the above lens combination, the first lens L1, the second lens L2, the third lens L3 and the eighth lens L8 are mainly responsible for the deflection of the light angle and reducing the height of the light. Such a layout is beneficial to the correction of distortion and off-axis field curvature; the fourth lens L4 and the fifth lens L5, the sixth lens L6 and the seventh lens L7 are combined into a cemented lens. The combined focal length of the fourth lens L4 and the fifth lens L5 is positive, and the combination of the sixth lens L6 and the seventh lens L7 is negative. Such a combination is beneficial to reducing the chromatic aberration of the front group of lenses; the remaining lenses are responsible for correcting the remaining aberrations of the optical system.

[0044] As described above, the technical solution adopts a combination of fourteen lenses. By reasonably matching and combining the diopter, shape, and material of each optical lens, meeting the above configuration is beneficial to ensuring a 1-inch target surface UAV imaging lens with a focal length of 6.6 mm for a UAV imaging lens, a wavelength of visible light, a field angle of 104°, and an aperture F of 2.8. This lens can image at infinity and meet the requirements of low distortion and achromatism.

[0045] In some embodiments of the present invention, the UAV imaging lens satisfies the relationship: 2 < f1 / f < 7; where f is the focal length of the UAV imaging lens, and f1 is the focal length of the first lens L1. Meeting this condition is more beneficial to the deflection of light by reducing the focal length of the first lens L1.

[0046] In some embodiments of the present invention, the UAV imaging lens satisfies the relationship: 2 < f1 / f8 < 5; where f1 is the focal length of the first lens L1, and f8 is the focal length of the eighth lens L8. Meeting this condition is more beneficial to the correction of distortion and field curvature by controlling the focal lengths of the first lens L1 and the eighth lens L8.

[0047] In some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the relational expression: -2 < f3 / f < 0; where f is the focal length of the imaging lens of the unmanned aerial vehicle, and f3 is the focal length of the third lens L3. Satisfying this condition is more conducive to correcting distortion and field curvature by controlling the focal length of the third lens L3.

[0048] In some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the following relational expression:

[0049] 1.73 < n(L1) < 1.85;

[0050] 38 < V(L1) < 52;

[0051] Where n(L1) is the refractive index of the first lens L1, and V(L1) is the Abbe number of the first lens L1. Controlling the refractive index and Abbe number of the first lens L1 is more conducive to the refraction of light and the correction of aberration.

[0052] In some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the following relational expression:

[0053] 1.62 < n(L8) < 1.73;

[0054] 50 < V(L8) < 60;

[0055] Where n(L8) is the refractive index of the eighth lens L8, and V(L8) is the Abbe number of the eighth lens L8. Controlling the refractive index and Abbe number of the eighth lens L8 is more conducive to the refraction of light and the correction of aberration.

[0056] In some embodiments of the present invention, the imaging lens of the unmanned aerial vehicle satisfies the following relational expression:

[0057] 15 < V(L4) - V(L5) < 25;

[0058] -30 < V(L6) - V(L7) < -20;

[0059] -25 < V(L9) - V(L10) < -10;

[0060] 30 < V(L11) - V(L12) < 40;

[0061] 45 < V(L13) - V(L14) < 55;

[0062] Among them, V(L4), V(L5), V(L6), V(L7), V(L9), V(L10), V(L11), V(L12), V(L13), and V(L14) are the Abbe numbers of the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, and the fourteenth lens L14, respectively. For UAV imaging lenses that satisfy the above relationship, increasing the Abbe number difference and refractive index difference between the fourth lens L4 and the fifth lens L5, the sixth lens L6 and the seventh lens L7, the ninth lens L9 and the tenth lens L10, the eleventh lens L11 and the twelfth lens L12, and the thirteenth lens L13 and the fourteenth lens L14 is more conducive to eliminating chromatic aberration.

[0063] In some embodiments of the present invention, the fourth lens L4 and the fifth lens L5 are cemented lens groups, the sixth lens L6 and the seventh lens L7 are cemented lens groups, the ninth lens L9 and the tenth lens L10 are cemented lens groups, the eleventh lens L11 and the twelfth lens L12 are cemented lens groups, and the thirteenth lens L13 and the fourteenth lens L14 are cemented lens groups. It can be understood that a cemented lens group means that there is no air gap between the two lenses. Cemented lens groups are beneficial for the correction of on-axis and off-axis chromatic aberration.

[0064] In some embodiments of the present invention, an aperture ST is provided between the seventh lens L7 and the eighth lens L8, and the aperture ST is in the middle position to limit the beam aperture.

[0065] In this embodiment, the relevant parameters of each lens are shown in the table below:

[0066]

[0067]

[0068] Table 1

[0069] In some embodiments of the present invention, the focal length of the UAV imaging lens is F = 6.6 mm, the aperture value is FNO = 2.8, the shooting distance is infinity, the optical distortion is ≤5%, the maximum field of view is 2ω: 104°, the total optical length is ∑ = 40.29 mm, and the applicable spectral range is visible light.

[0070] Figures 3 to 5 This is an optical performance diagram of an embodiment of the present invention, used to evaluate the resolving power of the optical system. Figure 3 The MTF curve of the drone imaging lens. Figure 4 This is a schematic diagram of field curvature and distortion of a drone imaging lens. Figure 5 This is a schematic diagram of the point array of the drone's imaging lens, from... Figure 3It can be seen that the MTF of all fields of view is greater than 0.3 at 100 lp / mm, indicating excellent resolution; from Figure 4 It can be seen that the optical distortion of the entire system is within -0.5%, which is relatively small and can maximize the authenticity and integrity of the image. Figure 5 As can be seen, the center blur spots are all less than 4.5µm, and the root mean square of the blur spots across the entire field of view is less than 9µm. The light converges well on the chip surface, and the overall uniformity is good, which can ensure the clarity and uniformity of the image.

[0071] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An imaging lens for unmanned aerial vehicles (UAVs), characterized in that, It consists of a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), an eighth lens (L8), a ninth lens (L9), a tenth lens (L10), an eleventh lens (L11), a twelfth lens (L12), a thirteenth lens (L13), and a fourteenth lens (L14) arranged in sequence from the object side to the image side. The first lens (L1) is a meniscus positive refractive power lens with the convex surface facing the object surface; the second lens (L2) is a meniscus negative refractive power lens with the convex surface facing the object surface; the third lens (L3) is a meniscus negative refractive power lens with the convex surface facing the object surface; the fourth lens (L4) is a meniscus negative refractive power lens with the convex surface facing the object surface; the fifth lens (L5) is a biconvex positive refractive power lens, the sixth lens (L6) is a biconcave negative refractive power lens, the seventh lens (L7) is a biconvex positive refractive power lens, the eighth lens (L8) is a biconvex positive refractive power lens, the ninth lens (L9) is a biconvex positive refractive power lens, the tenth lens (L10) is a biconcave negative refractive power lens; the eleventh lens (L11) is a meniscus positive refractive power lens with the convex surface facing the image surface; the twelfth lens (L12) is a meniscus negative refractive power lens with the convex surface facing the image surface; the thirteenth lens (L13) is a biconvex positive refractive power lens; the fourteenth lens (L14) is a meniscus negative refractive power lens with the convex surface facing the image surface. The drone imaging lens satisfies the relation: -2 < f3 / f < 0; where f is the focal length of the drone imaging lens, and f3 is the focal length of the third lens (L3). The fourth lens (L4) and the fifth lens (L5) form a cemented lens group, the sixth lens (L6) and the seventh lens (L7) form a cemented lens group, the ninth lens (L9) and the tenth lens (L10) form a cemented lens group, the eleventh lens (L11) and the twelfth lens (L12) form a cemented lens group, the thirteenth lens (L13) and the fourteenth lens (L14) form a cemented lens group.

2. The UAV imaging lens according to claim 1, characterized in that: The drone imaging lens satisfies the relation: 2 < f1 / f < 7; where f is the focal length of the drone imaging lens, and f1 is the focal length of the first lens (L1).

3. The UAV imaging lens according to claim 1, characterized in that: The drone imaging lens satisfies the relation: 2 < f1 / f8 < 5; where f1 is the focal length of the first lens (L1), and f8 is the focal length of the eighth lens (L8).

4. The UAV imaging lens according to claim 1, characterized in that: The drone imaging lens satisfies the following relations: 1.73 < n(L1) < 1.85; 38 < V(L1) < 52; where n(L1) is the refractive index of the first lens (L1), and V(L1) is the Abbe number of the first lens (L1).

5. The UAV imaging lens according to claim 1, characterized in that: The drone imaging lens satisfies the following relations: 1.62 < n(L8) < 1.73; 50 < V(L8) < 60; Wherein, n(L8) is the refractive index of the eighth lens (L8), and V(L8) is the Abbe number of the eighth lens (L8).

6. The UAV imaging lens according to claim 1, characterized in that: The UAV imaging lens satisfies the following relationship: 15 <V(L4)-V(L5)<25; -30 <V(L6)-V(L7)<-20; -25 <V(L9)-V(L10)<-10; 30 <V(L11)-V(L12)<40; 45 <V(L13)-V(L14)<55; Among them, V(L4), V(L5), V(L6), V(L7), V(L9), V(L10), V(L11), V(L12), V(L13) and V(L14) are the Abbe numbers of the fourth lens (L4), the fifth lens (L5), the sixth lens (L6), the seventh lens (L7), the ninth lens (L9), the tenth lens (L10), the eleventh lens (L11), the twelfth lens (L12), the thirteenth lens (L13), and the fourteenth lens (L14), respectively.

7. The UAV imaging lens according to claim 1, characterized in that: An aperture (STO) is provided between the seventh lens (L7) and the eighth lens (L8).

8. The UAV imaging lens according to claim 1, characterized in that: The drone imaging lens has a focal length of F=6.6mm and an aperture value of FNO=2.8.

Images