80-degree field-of-view visible light lens for low-altitude aerial photography

Abstract

A 80-degree field-of-view visible light lens for low-altitude aerial photography comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged from an object side to an image side, the second lens has negative focal power, and the second lens and the first lens are arranged at an interval; the third lens has negative focal power, and the third lens and the second lens are arranged at an interval; the fourth lens has positive focal power, and the fourth lens and the third lens are arranged at an interval; the diaphragm and the fourth lens are arranged at an interval and the diaphragm is used for limiting the aperture of the light beam; the fifth lens has negative focal power, and the fifth lens and the diaphragm are arranged at an interval; the sixth lens has negative power, and the sixth lens and the fifth lens are arranged at an interval; the seventh lens has negative focal power, and the seventh lens and the sixth lens are arranged at an interval; and the eighth lens has negative focal power, and the eighth lens and the seventh lens are arranged at an interval. The lens is simple in structure, high in imaging transfer function and low in distortion, the field of view is fixed to be 80 degrees, and the requirement for low-altitude aerial photography large-range search imaging is met.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical lenses, and specifically relates to a visible light lens for low-altitude aerial photography, which is especially suitable for the fields of aerial mapping and reconnaissance of unmanned aerial vehicles and can realize aerial imaging under a field of view of 80 degrees. Background Art

[0002] The aviation field requires the lens to clearly image ground targets at high altitudes, with constantly changing parameters such as ambient temperature and atmospheric pressure. When drones are used, the aerial mapping lens used by drones has strict requirements on the imaging field of view, imaging transfer function and weight. In addition, drones should be adapted to all-weather imaging under complex climatic conditions. Consistent imaging in daytime, night, fog or wind and rain directly affects the wide use of drones. At the same time, wide-angle lenses can expand the search range and improve search efficiency, but at the same time they will cause distortion and a decrease in imaging quality.

[0003] At present, the optical design of aerial mapping lenses cannot meet the actual needs, and the lens standardization is low. In particular, in order to improve the search efficiency, the use of large field of view lenses generally has poor image quality, distortion, clarity and saturation, etc., which cannot meet the actual requirements of aerial ground photography. This has greatly increased the limitations of drone aerial mapping and reconnaissance. Utility Model Content

[0004] In view of this, the purpose of the utility model is to provide an aerial imaging lens with an 80° field of view. The lens has a simple structure, a fixed field of view of 80°, a high imaging transfer function and low distortion. Since its field of view is fixed at 80°, it can be disassembled and assembled on the drone at any time according to the usage as a standard lens, to achieve a wide-angle search with a field of view of 80°, to expand the search range, and to cooperate with other small field of view lenses to achieve the search-precise positioning function.

[0005] To achieve the above objectives, the following optical design technology solutions are adopted:

[0006] The utility model provides a low-altitude aerial photography lens with an 80° field of view, which includes the following components arranged in sequence from the object side to the image side:

[0007] A first lens having positive optical power;

[0008] a second lens having negative optical power and spaced apart from the first lens;

[0009] a third lens having negative optical power and spaced apart from the second lens;

[0010] a fourth lens having positive refractive power and spaced apart from the third lens;

[0011] an aperture, which is spaced apart from the fourth lens and is used to limit the beam aperture;

[0012] A fifth lens having negative optical power and spaced apart from the aperture stop;

[0013] a sixth lens having negative focal power and spaced apart from the fifth lens;

[0014] a seventh lens having negative optical power and spaced apart from the sixth lens;

[0015] The eighth lens has negative optical power and is spaced apart from the seventh lens.

[0016] Furthermore,

[0017] The first lens has a concave surface facing the image side and a convex surface facing the object side;

[0018] The second lens is a biconcave lens;

[0019] The third lens has a convex surface facing the image side and a flat surface facing the object side;

[0020] The fourth lens has a concave surface facing the image side and a convex surface facing the object side;

[0021] The fifth lens has a flat surface facing the image side and a convex surface facing the object side;

[0022] The sixth lens is a biconcave lens;

[0023] The seventh lens is a biconvex lens;

[0024] The eighth lens has a flat surface facing the image side and a convex surface facing the object side.

[0025] Furthermore, the material of the first lens is H-ZF88, the thickness is 10 mm, and the curvature radii of the front and rear surfaces of the first lens are 60.80 mm and 22.59 mm respectively.

[0026] Furthermore, the material of the second lens is H-FK71, the distance between the second lens and the first lens is 11.83 mm, the thickness is 3 mm, and the curvature radii of the front and rear surfaces of the second lens are -59.37 mm and 36.01 mm respectively.

[0027] Furthermore, the material of the third lens is H-FK71, the distance between the third lens and the second lens is 29.91 mm, the thickness is 9.5 mm, and the curvature radii of the front and rear surfaces of the third lens are -1891.72 mm and -36.40 mm respectively.

[0028] Furthermore, the fourth lens is made of H-ZF62, has a distance of 0.2 mm from the third lens, a thickness of 4.6 mm, and curvature radii of the front and rear surfaces of the fourth lens are 66.21 mm and 191.10 mm, respectively.

[0029] Furthermore, the distance between the aperture stop and the fourth lens is 38.17 mm, and the distance between the aperture stop and the fifth lens is 0.2 mm.

[0030] Furthermore, the material of the fifth lens is H-FK71, the thickness is 4 mm, and the curvature radii of the front and rear surfaces of the fifth lens are 13.49 mm and -37.35 mm respectively.

[0031] Furthermore, the sixth lens is made of H-ZF11, the distance between the sixth lens and the fifth lens is 1.38 mm, the thickness is 4.3 mm, and the curvature radii of the front and rear surfaces of the sixth lens are -24.52 mm and 15.84 mm respectively.

[0032] Furthermore, the seventh lens is made of H-FK71, the distance between the seventh lens and the sixth lens is 1.73 mm, the thickness is 4.5 mm, and the curvature radii of the front and rear surfaces of the seventh lens are 41.86 mm and -20.07 mm respectively.

[0033] Furthermore, the material of the eighth lens is H-ZLAF68C, the distance between the eighth lens and the seventh lens is 0.2 mm, the thickness is 3 mm, and the curvature radii of the front and rear surfaces of the eighth lens are 70.25 mm and 576.02 mm respectively.

[0034] The 80° field of view visible light lens for low-altitude aerial photography of the utility model can also include a lens barrel. There is no special restriction on the lens barrel, and it can fix the above-mentioned first lens, second lens, third lens, fourth lens, aperture, fifth lens, sixth lens and seventh lens.

[0035] Compared with the prior art, the beneficial effects of the utility model are:

[0036] The utility model has an 80° field of view visible light lens for low-altitude aerial photography, which has a simple structure, a fixed viewing angle of 80°, a high imaging transfer function and low distortion. The visible light lens can achieve full-field MTF>0.6@50lp / mm, full-field maximum distortion <10%, illumination full-field uniformity better than 80%, and full-field point diagram RMS radius ≤7.5μm. It meets the imaging requirements of low-altitude aerial photography, large-scale search imaging, especially the search and mapping of ground color targets and other application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 This is a schematic diagram of the structure of the 80° field of view visible light lens for low-altitude aerial photography of the utility model;

[0039] In the figure, 1 is the first lens, 2 is the second lens, 3 is the third lens, 4 is the fourth lens, 5 is the aperture, 6 is the fifth lens, 7 is the sixth lens, 8 is the seventh lens, and 9 is the eighth lens.

[0040] Figure 2 This is the full-field MTF diagram of the visible light lens in Example 1 of the utility model;

[0041] Figure 3 This is a diagram showing the maximum distortion of the entire field of view of the visible light lens in Example 1 of the utility model;

[0042] Figure 4 The uniformity of illumination over the entire field of view of the visible light lens in Example 1 of the utility model;

[0043] Figure 5 This is a full-field spot diagram of the visible light lens in Example 1 of the utility model. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0045] Example 1

[0046] The technical indicators of the optical lens are as follows: size: φ52×150mm; wavelength 0.45μm~0.89μm; back working distance: 23.5mm; maximum aperture of the lens: φ54mm; full field MTF>0.6@50lp / mm, full field maximum distortion <10%; illumination full field uniformity better than 80%; full field point diagram RMS radius ≤7.5μm;

[0047] Based on the above technical indicators, the designed optical lens, such as Figure 1 As shown, the parameters of each optical element (radius, curvature, thickness, spacing, material, etc.) are shown in Table 1.

[0048] Table 1 Parameters of the optical elements of the optical lens of Example 1

[0049] SurfTypeRadius(mm)Thickness(mm)GlassDiameter(mm)ConicComment OBJSTANDARDInfinityInfinity00 1STANDARDInfinity2094.130 2STANDARD60.8010H-ZF8851.120QL1 3STANDARD22.5911.8334.900 4STANDARD-59.373H-FK7134.350QL2 5STANDARD36.0129.9132.890 6STANDARD-1891.729.5H-FK7139.310QL3 7STANDARD-36.400.240.020 8STANDARD66.214.6H-ZF6237.110QL4 9STANDARD191.1038.1735.850 STOSTANDARDInfinity0.28.590 11STANDARD13.494H-FK719.180HL1 12STANDARD-37.351.389.590 13STANDARD-24.524.3H-ZF119.700HL2 14STANDARD15.841.7310.950 15STANDARD41.864.5H-FK7112.240HL3 16STANDARD-20.070.213.840 17STANDARD70.253H-ZLAF68C14.730HL4 18STANDARD576.0223.4615.150 19STANDARDInfinity-0.03322.720 IMASTANDARDInfinity22.710

[0050] After testing, the full-field MTF of the optical lens of Example 1 is as follows: Figure 2 As shown, the maximum distortion of the entire field of view is Figure 3 As shown, the uniformity of illumination over the entire field of view is as follows Figure 4 As shown, the full field point diagram is as follows Figure 5 It can be seen that the optical lens of Example 1 has a high imaging transfer function, low distortion, good imaging clarity, good uniformity, and strong anti-interference ability.

[0051] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the embodiments. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. 80° field of view visible light lens for low altitude aerial photography, characterized by: Including the following arranged from the object side to the image side: A first lens (1) having positive optical power; a second lens (2) having negative optical power and spaced apart from the first lens (1); a third lens (3) having negative optical power and spaced apart from the second lens (2); a fourth lens (4) having positive refractive power and spaced apart from the third lens (3); An aperture (5) which is spaced apart from the fourth lens (4) and is used to limit the aperture of the light beam; a fifth lens (6) having negative optical power and spaced apart from the aperture stop (5); a sixth lens (7) having negative focal power and spaced apart from the fifth lens (6); a seventh lens (8) having negative optical power and spaced apart from the sixth lens (7); The eighth lens (9) has negative optical power and is spaced apart from the seventh lens (8).

2. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The first lens (1) has a concave surface facing the image side and a convex surface facing the object side; The second lens (2) is a biconcave lens; The third lens (3) has a convex surface facing the image side and a flat surface facing the object side; The fourth lens (4) has a concave surface facing the image side and a convex surface facing the object side; The fifth lens (6) has a flat surface facing the image side and a convex surface facing the object side; The sixth lens (7) is a biconcave lens; The seventh lens (8) is a biconvex lens; The eighth lens (9) has a flat surface facing the image side and a convex surface facing the object side.

3. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The material of the first lens (1) is H-ZF88, with a thickness of 10 mm. The curvature radii of the front and rear surfaces of the first lens (1) are 60.80 mm and 22.59 mm respectively.

4. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The material of the second lens (2) is H-FK71, the distance between the second lens (2) and the first lens (1) is 11.83 mm, the thickness is 3 mm, and the curvature radii of the front and rear surfaces of the second lens (2) are -59.37 mm and 36.01 mm respectively.

5. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The material of the third lens (3) is H-FK71, the distance between the third lens (3) and the second lens (2) is 29.91 mm, the thickness is 9.5 mm, and the curvature radii of the front and rear surfaces of the third lens (3) are -1891.72 mm and -36.40 mm respectively.

6. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The fourth lens (4) is made of H-ZF62, has a distance of 0.2 mm from the third lens (3), a thickness of 4.6 mm, and a curvature radius of the front and rear surfaces of the fourth lens (4) of 66.21 mm and 191.10 mm respectively; The distance between the aperture (5) and the fourth lens (4) is 38.17 mm, and the distance between the aperture (5) and the fifth lens (6) is 0.2 mm.

7. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The material of the fifth lens (6) is H-FK71, with a thickness of 4 mm. The curvature radii of the front and rear surfaces of the fifth lens (6) are 13.49 mm and -37.35 mm respectively.

8. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The sixth lens (7) is made of H-ZF11, has a distance of 1.38 mm from the fifth lens (6), a thickness of 4.3 mm, and a curvature radius of the front and rear surfaces of the sixth lens (7) of -24.52 mm and 15.84 mm respectively.

9. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The seventh lens (8) is made of H-FK71, has a distance of 1.73 mm from the sixth lens (7), a thickness of 4.5 mm, and a curvature radius of the front and rear surfaces of the seventh lens (8) of 41.86 mm and -20.07 mm respectively.

10. The 80° field of view visible light lens for low-altitude aerial photography according to claim 1, characterized in that: The eighth lens (9) is made of H-ZLAF68C, has a distance of 0.2 mm from the seventh lens (8), a thickness of 3 mm, and a curvature radius of the front and rear surfaces of the eighth lens (9) of 70.25 mm and 576.02 mm respectively.

Images