A drone lens

Abstract

This utility model discloses a drone lens, arranged sequentially from the object side to the image side along the lens optical axis: a first lens with negative optical power, its object side being convex and its image side being concave; a second lens with negative optical power, which is a paraxial convex-concave lens; a third lens with positive optical power, both its object side and image side being convex; an aperture stop; a fourth lens with positive optical power, both its object side and image side being convex; a fifth lens with negative optical power, its object side being convex and its image side being concave; a sixth lens with positive optical power, which is a paraxial convex-convex lens; a seventh lens with negative optical power, which is a paraxial convex-concave lens; and an eighth lens with negative optical power, which is a paraxial convex-concave lens. The optical lens provided by this utility model can be paired with a 1 / 1.3” inch chip, with a field of view of 82°, achieving lightweight, high resolution, low distortion, and minimal purple fringing in the drone lens.

Description

Technical Field

[0001] This utility model relates to the field of optical lenses, and in particular to a drone lens. Background Technology

[0002] With the rapid development and widespread application of drone technology, higher demands are being placed on the optical lenses it carries. However, existing lens technology has the following shortcomings: First, insufficient miniaturization; the complex optical structure results in large and heavy lenses, making it difficult to meet the core requirement of lightweight drones. Second, low resolution; it is difficult to support high-resolution imaging, limiting the ability to capture and analyze image details, and affecting the imaging quality of aerial photography and professional applications. Third, limited target surface compatibility; the imaging circle of existing lenses is relatively small and cannot be matched with large target surface chips. These key defects severely restrict the performance and development space of drones in high-end application scenarios such as precision operations and professional-grade image acquisition. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a drone lens. The lens adopts a hybrid combination of one spherical glass, one aspherical glass and six aspherical plastic pieces, and can be equipped with a 1 / 1.3” chip. It has a field of view of 82° and can achieve lightweight, high resolution, low distortion and small purple fringing in drone lenses.

[0004] The objective of this utility model is achieved through the following technical solution:

[0005] A drone lens, arranged sequentially from the object side to the image side along the lens optical axis:

[0006] The first lens is a spherical glass lens with negative optical power, wherein the object side is convex and the image side is concave.

[0007] The second lens is an aspherical plastic lens with negative optical power, which is a paraxial convex-concave lens.

[0008] The third lens is an aspherical glass lens with positive optical power, and both its object side and image side are convex.

[0009] Aperture stop;

[0010] The fourth lens is an aspherical plastic lens with positive optical power, and both its object-side surface and image-side surface are convex.

[0011] The fifth lens is an aspherical plastic lens with negative optical power, whose object side is convex and image side is concave.

[0012] The sixth lens is an aspherical plastic lens with positive optical power, and it is a paraxial convex lens.

[0013] The seventh lens is an aspherical plastic lens with negative optical power, which is a paraxial convex-concave lens;

[0014] The eighth lens is an aspherical plastic lens with negative optical power, which is a paraxial convex-concave lens;

[0015] A filter, wherein the filter is disposed on the image-side surface of the eighth lens;

[0016] An imaging surface is disposed on the image-side surface of the filter.

[0017] Furthermore, in this invention, considering the aberrations of the optical system and different focal distances, the focal lengths, refractive indices, and radii of curvature of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, and eighth lens respectively satisfy the following conditions:

[0018] f2 -16.58～-13.57 ND2 1.60～1.70 R21 +8.86～+13.46 R22 +4.66～+5.32 f3 +6.75～+8.32 ND3 1.50～1.70 R31 +6.9～+10.43 R32 -10.75～-7.64 f4 +10.13～+12.38 ND4 1.50～1.60 R41 +8.34～+41.12 R42 -19.66～-14.34 f5 -42.36～-33.98 ND5 1.60～1.70 R51 +3.53～+4.16 R52 +2.89～+3.34 f6 +33.67～+41.18 ND6 1.50～1.60 R61 +14.5～+127.15 R62 -32.39～+52.92 f7 -26.90～-21.98 ND7 1.60～1.70 R71 +7.92～+7.94 R72 +4.74～+5.18 f8 -581.18～-77.49 ND8 1.50～1.60 R81 +5.14～+5.66 R82 +5.16～+5.84

[0019] Where f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the radius of curvature of the object side surface of the first lens, and R12 is the radius of curvature of the image side surface of the first lens.

[0020] f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the radius of curvature of the object side surface of the second lens, and R22 is the radius of curvature of the image side surface of the second lens.

[0021] f3 is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the radius of curvature of the object side of the third lens, and R32 is the radius of curvature of the image side of the third lens.

[0022] f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, R41 is the radius of curvature of the object side of the fourth lens, and R42 is the radius of curvature of the image side of the fourth lens.

[0023] f5 is the focal length of the fifth lens, ND5 is the refractive index of the fifth lens, R51 is the radius of curvature of the object side of the fifth lens, and R52 is the radius of curvature of the image side of the fifth lens.

[0024] f6 is the focal length of the sixth lens, ND6 is the refractive index of the sixth lens, R61 is the radius of curvature of the object side surface of the sixth lens, and R62 is the radius of curvature of the object side surface of the sixth lens.

[0025] f7 is the focal length of the seventh lens, ND7 is the refractive index of the seventh lens, R71 is the radius of curvature of the object side of the seventh lens, and R72 is the radius of curvature of the image side of the seventh lens.

[0026] f8 is the focal length of the eighth lens, ND8 is the refractive index of the eighth lens, R81 is the radius of curvature of the object side of the eighth lens, and R82 is the radius of curvature of the image side of the eighth lens.

[0027] Focal length: "+" indicates that the lens has positive power, and "-" indicates that the lens has negative power. The unit is mm.

[0028] Radius of curvature: "+" indicates that the surface bends toward the image plane, and "-" indicates that the surface bends toward the object plane. The unit is mm.

[0029] Furthermore, in this invention, to achieve better performance of the optical system, we need to rationally select lens materials, rationally allocate the focal lengths of each lens, and rationally optimize the optical system during the design process to correct system aberrations and ultimately optimize the performance of the optical system. The ratio of the focal length of each lens to the total focal length of the lens also satisfies the following conditions:

[0030] -3.04≤f1 / f≤-2.45,

[0031] -2.21≤f² / f≤-1.81,

[0032] 0.9≤f³ / f≤1.11

[0033] 1.35≤f4 / f≤1.65

[0034] -5.65≤f5 / f≤-4.53,

[0035] 4.49≤f6 / f≤5.49

[0036] -3.58≤f7 / f≤-2.93,

[0037] -77.49≤f8 / f≤-63.4;

[0038] In the formula, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

[0039] Furthermore, in this utility model,

[0040] The aperture of the lens is F#, which satisfies F#≤1.7;

[0041] The total optical length of the lens is TTL, which satisfies TTL≤17mm;

[0042] The total focal length of the lens is f, which satisfies f≤7.5mm;

[0043] The optical back focal length of the lens is OBFL, which satisfies OBFL≥2.2mm.

[0044] Furthermore, in this invention, the lens also satisfies the following relationship:

[0045] IC / TTL≥0.73,

[0046] TTL / f≤2.3,

[0047] OBFL / TTL ≥ 0.12;

[0048] In the formula, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focal length of the lens, the optical back focal length is the distance from the point on the image side of the eighth lens closest to the image plane to the image plane, and IC is the full image height of the 1 / 1.3” chip paired with the lens.

[0049] Furthermore, the aspherical surfaces of the second, third, fourth, fifth, sixth, seventh, and eighth lenses satisfy the following formula:

[0050]

[0051] In the formula, Z is the sag of the lens along the optical axis, k is the conic coefficient of the quadratic surface, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

[0052] The beneficial effects of this utility model are:

[0053] The drone lens of this utility model has a total focal length f≤7.5mm and an aperture F#≤1.7, which can provide high-definition image quality under a wide field of view.

[0054] In terms of manufacturing, the lens uses a hybrid combination of one spherical glass element, one aspherical glass element, and six aspherical plastic elements, resulting in a compact structure that achieves small size, light weight, good performance, and low cost, offering high cost-effectiveness.

[0055] This invention, by rationally setting the optical power and surface shape of each lens, helps to reduce aberrations and chromatic aberrations in lens imaging, while having a large field of view and high imaging quality. It can be matched with a 1 / 1.3” large target surface chip to achieve high-definition imaging, better meeting the high image quality and wide-angle shooting needs of drones. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of the optical structure of Embodiment 1 of the present invention;

[0057] Figure 2 This is a visible light 0.435-0.656μm FFT MTF (100lp / mm) curve of Embodiment 1 of this utility model;

[0058] Figure 3 This is a chromatic aberration curve of visible light 0.435-0.656μm perpendicular to the axis of Embodiment 1 of this utility model;

[0059] Figure 4 This is a field curvature curve of visible light at 0.435-0.656 μm for Embodiment 1 of this utility model;

[0060] Figure 5 This is a visible light 0.546μm F-Tan (Theta) distortion curve of Embodiment 1 of this utility model;

[0061] Figure 6 This is a schematic diagram of the optical structure of Embodiment 2 of the present invention;

[0062] Figure 7 This is a visible light 0.435-0.656μm FFT MTF (100lp / mm) curve of Embodiment 2 of this utility model;

[0063] Figure 8 This is a chromatic aberration curve of visible light 0.435-0.656μm vertical axis in Embodiment 2 of this utility model;

[0064] Figure 9 This is a field curvature curve of visible light at 0.435-0.656μm in Embodiment 2 of this utility model;

[0065] Figure 10 This is a visible light 0.546μm F-Tan (Theta) distortion curve of Embodiment 2 of this utility model; reference numerals: L1-first lens, L2-second lens, L3-third lens, L4-fourth lens, L5-fifth lens, L6-sixth lens, L7-seventh lens, L8-eighth lens, ST-aperture stop, CG-filter, IMA-imaging surface. Detailed Implementation

[0066] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. In this specification, the expressions "first," "second," "third," etc., are only used to distinguish one feature from another, and do not indicate any limitation on the features. The shape of the spherical or aspherical surface is not limited to the spherical or aspherical shapes shown in the drawings. The drawings are for illustrative purposes only and are not strictly drawn to scale.

[0067] In this invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region; if the lens surface is not defined as convex, concave, or flat, it means that the lens surface can be convex, concave, or flat. The surface of each lens closest to the object being photographed is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0068] Unless otherwise specified, all terms used in this invention (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the same meaning as they have in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense, unless expressly so defined in this invention.

[0069] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0070] like Figure 1 and Figure 6 As shown in the figure, an embodiment of this utility model provides a drone lens. The surface of the lens adjacent to the object plane is the object-side surface, and the surface of the lens adjacent to the image plane is the image-side surface. Along the lens optical axis from the object side to the image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, an aperture stop ST, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a filter CG, and an imaging surface IMA are arranged sequentially. The aperture stop ST is located between the fourth lens L4 and the fifth lens L5. The filter CG is located on the image-side surface of the eighth lens L8, and the imaging surface IMA is located on the image-side surface of the filter CG. The imaging surface IMA includes a protective glass and an image acquisition element. The protective glass is made of H-K9L glass and is integrated onto the image acquisition element.

[0071] in:

[0072] The first lens L1 is a spherical glass lens with negative optical power, its object side is convex and its image side is concave.

[0073] The second lens L2 is an aspherical plastic lens with negative optical power and is a paraxial convex-concave lens.

[0074] The third lens L3 is an aspherical glass lens with positive optical power, and both its object side and image side are convex.

[0075] Aperture stop ST;

[0076] The fourth lens L4 is an aspherical plastic lens with positive optical power, and both its object side and image side are convex.

[0077] The fifth lens L5 is an aspherical plastic lens with negative optical power. Its object side is convex and its image side is concave.

[0078] The sixth lens L6 is an aspherical plastic lens with positive optical power and is a paraxial convex lens.

[0079] The seventh lens L7 is an aspherical plastic lens with negative optical power and is a paraxial convex-concave lens.

[0080] The eighth lens, L8, is an aspherical plastic lens with negative optical power and is a paraxial convex-concave lens.

[0081] The optical lens used in this drone lens can be made of either glass or plastic. Using plastic effectively reduces production costs. Using glass effectively improves the lens's thermal stability. This lens employs a hybrid combination of one spherical glass element, one aspherical glass element, and six aspherical plastic elements, resulting in a compact structure that achieves small size, light weight, good performance, and low cost, offering high cost-effectiveness.

[0082] In this invention, considering the aberrations of the optical system and different focal distances, the focal lengths, refractive indices, and radii of curvature of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 respectively satisfy the following conditions:

[0083]

[0084]

[0085] Where f1 is the focal length of the first lens, ND1 is the refractive index of the first lens, R11 is the radius of curvature of the object side surface of the first lens, and R12 is the radius of curvature of the image side surface of the first lens.

[0086] f2 is the focal length of the second lens, ND2 is the refractive index of the second lens, R21 is the radius of curvature of the object side surface of the second lens, and R22 is the radius of curvature of the image side surface of the second lens.

[0087] f3 is the focal length of the third lens, ND3 is the refractive index of the third lens, R31 is the radius of curvature of the object side of the third lens, and R32 is the radius of curvature of the image side of the third lens.

[0088] f4 is the focal length of the fourth lens, ND4 is the refractive index of the fourth lens, R41 is the radius of curvature of the object side of the fourth lens, and R42 is the radius of curvature of the image side of the fourth lens.

[0089] f5 is the focal length of the fifth lens, ND5 is the refractive index of the fifth lens, R51 is the radius of curvature of the object side of the fifth lens, and R52 is the radius of curvature of the image side of the fifth lens.

[0090] f6 is the focal length of the sixth lens, ND6 is the refractive index of the sixth lens, R61 is the radius of curvature of the object side surface of the sixth lens, and R62 is the radius of curvature of the object side surface of the sixth lens.

[0091] f7 is the focal length of the seventh lens, ND7 is the refractive index of the seventh lens, R71 is the radius of curvature of the object side of the seventh lens, and R72 is the radius of curvature of the image side of the seventh lens.

[0092] f8 is the focal length of the eighth lens, ND8 is the refractive index of the eighth lens, R81 is the radius of curvature of the object side of the eighth lens, and R82 is the radius of curvature of the image side of the eighth lens.

[0093] Focal length: "+" indicates that the lens has positive power, and "-" indicates that the lens has negative power. The unit is mm.

[0094] Radius of curvature: "+" indicates that the surface bends toward the image plane, and "-" indicates that the surface bends toward the object plane. The unit is mm.

[0095] In this invention, to achieve better performance of the optical system, the design process involves rationally selecting lens materials, rationally allocating the focal lengths of each lens, and rationally optimizing the optical system to correct aberrations and ultimately optimize its performance. In this invention, f1 is the focal length of the first lens L1, f2 is the focal length of the second lens L2, f3 is the focal length of the third lens L3, f4 is the focal length of the fourth lens L4, f5 is the focal length of the fifth lens L5, f6 is the focal length of the sixth lens L6, f7 is the focal length of the seventh lens L7, f8 is the focal length of the eighth lens L8, and the total focal length of the lens is f. The ratio of the focal length of each lens to the total focal length of the lens satisfies the following condition:

[0096] -3.04≤f1 / f≤-2.45,

[0097] -2.21≤f² / f≤-1.81,

[0098] 0.9≤f³ / f≤1.11

[0099] 1.35≤f4 / f≤1.65

[0100] -5.65≤f5 / f≤-4.53,

[0101] 4.49≤f6 / f≤5.49

[0102] -3.58≤f7 / f≤-2.93,

[0103] -77.49≤f8 / f≤-63.4.

[0104] In this invention, f is the total focal length of the lens, TTL is the total optical length of the lens, OBFL is the optical back focal length of the lens, the optical back focal length is the distance from the point on the image side of the eighth lens L8 closest to the image plane to the image plane, and IC is the full image height of the 1 / 1.3” chip paired with the lens. They satisfy the following relationship:

[0105] F#≤1.7,

[0106] f≤7.5mm,

[0107] TTL≤17mm,

[0108] IC / TTL≥0.73,

[0109] TTL / f≤2.3,

[0110] OBFL / TTL≥0.12.

[0111] The aspherical surfaces of the second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, and eighth lens L8 in the drone lens provided by this utility model can all be defined by the following equation for even-order aspherical surfaces:

[0112]

[0113] In the formula, Z is the sag of the lens along the optical axis, k is the conic coefficient of the quadratic surface, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

[0114] The following provides specific embodiments based on the above-described configuration of this utility model, thereby specifically illustrating the drone lens of this utility model. To better understand and implement this utility model, it will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0115] The main element symbols in the specific embodiments of this utility model are explained in Table 1.

[0116] Table 1

[0117] S2 The image side of the first lens S12 The sixth lens object side S3 Second lens object side S13 The image side of the sixth lens S4 The image side of the second lens S14 Seventh lens object side S5 The third lens object side S15 The image side of the seventh lens S6 The image of the third lens is on the side. S16 Eighth lens object side S7 Aperture S17 The image side of the eighth lens S8 Fourth lens object side S18 Filter S9 The image side of the fourth lens S19 Imaging surface S10 Fifth lens object side

[0118] The data summary of specific embodiments of this utility model is shown in Table 2 below:

[0119] Table 2

[0120]

[0121]

[0122] Example 1

[0123] like Figure 1 The diagram shown is a schematic representation of the optical structure of Embodiment 1. In this embodiment, the total focal length of the lens is f = 7.5mm, the aperture value is F# = 1.7, the total image height is IC = 12.5mm, the field of view (DFOV) is 82°, the total optical length (TTL) of the lens is 17mm, and the optical back focal length (OBFL) of the lens system is 2.2mm.

[0124] In this embodiment, considering the aberrations of the optical system, the curvature radius, center thickness, refractive index, Abbe constant, and aspherical K value of each lens are designed as shown in Table 3.

[0125] Table 3 provides the radius of curvature R (in mm), center thickness d (in mm), refractive index (ND), Abbe constant (VD), and aspherical K value (Conic) for each lens.

[0126] Table 2

[0127]

[0128]

[0129] In Table 3, the radius of curvature R represents the curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INFINITY" indicates that the surface is flat. The center thickness D represents the central axial distance from the current surface to the next surface. The refractive index ND represents the ability of the current lens material to deflect light. The Abbe number VD represents the dispersion characteristics of the current lens material. The k value represents the magnitude of the best-fit conic coefficient of the aspherical surface.

[0130] In this embodiment, the aspherical surfaces of the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 can all be defined by the above-described equations for even-order aspherical surfaces. The coefficients of the aspherical surfaces of each optical surface of the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are shown in Table 4.

[0131] Table 4

[0132]

[0133]

[0134] like Figure 2 The figure shows the MTF curve of the lens in this embodiment. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, at a spatial frequency of 100 lp / mm, the MTF value of the lens across the entire field of view is >0.5, indicating that the lens has high resolution and can achieve high-definition quality.

[0135] like Figure 3 The figure shows the transverse chromatic aberration curve of the lens in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.546 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration values ​​of the longest and shortest wavelengths are controlled within ±2 μm, indicating that the transverse chromatic aberration of the optical lens is well corrected.

[0136] like Figure 4 The figure shows the field curvature curve of the lens in this embodiment, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within 0.05 mm, indicating that the field curvature of the optical lens is well corrected.

[0137] like Figure 5 The figure shows the F-Tan (Theta) distortion of the lens in this embodiment. The horizontal axis represents the F-Tan (Theta) distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tan (Theta) distortion of the lens is small and less than 3%, which can keep the magnification consistent at different positions in the actual shot.

[0138] Example 2

[0139] like Figure 6The diagram shown is a schematic representation of the optical structure of Embodiment 2. In this embodiment, the total focal length of the lens is f = 7.5mm, the aperture value is F# = 1.7, the holographic height is IC = 12.5mm, the field of view (DFOV) is 82°, the total optical length (TTL) of the lens is 17mm, and the optical back focal length (OBFL) of the lens system is 2.4mm.

[0140] In this embodiment 2, the radius of curvature R (unit: mm), center thickness d (unit: mm), refractive index (ND), Abbe constant (VD), and aspherical K value (Conic) of each lens are shown in Table 5.

[0141] Table 5

[0142]

[0143]

[0144] In Table 5, the radius of curvature R represents the curvature of the lens surface. A positive value indicates that the surface bends towards the image plane, and a negative value indicates that the surface bends towards the object plane. "INFINITY" indicates that the surface is flat. The center thickness D represents the central axial distance from the current surface to the next surface. The refractive index ND represents the ability of the current lens material to deflect light. The Abbe number VD represents the dispersion characteristics of the current lens material. The k value represents the magnitude of the best-fit conic coefficient of the aspherical surface.

[0145] In this embodiment 2, the coefficients of the aspherical surfaces of each optical surface of the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7 and the eighth lens L8 are shown in Table 6.

[0146] Table 6

[0147]

[0148]

[0149] In this embodiment:

[0150] like Figure 7 The figure shows the MTF curve of the lens in this embodiment. The horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the entire field of view is >0.45 at a spatial frequency of 100 lp / mm, indicating that the lens has high resolution and can achieve high-definition quality.

[0151] like Figure 8The figure shows the transverse chromatic aberration curve of the lens in this embodiment. It represents the chromatic aberration of each wavelength relative to the center wavelength (0.546 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the figure, the transverse chromatic aberration values ​​of the longest and shortest wavelengths are controlled within ±3 μm, indicating that the transverse chromatic aberration of the optical lens is well corrected.

[0152] like Figure 9 The figure shows the field curvature curve of the lens in this embodiment, which represents the degree of curvature of light of different wavelengths in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within 0.05 mm, indicating that the field curvature of the optical lens is well corrected.

[0153] like Figure 10 The figure shows the F-Tan (Theta) distortion of the lens in this embodiment. The horizontal axis represents the F-Tan (Theta) distortion (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Tan (Theta) distortion of the lens is small and less than 4%, which can keep the magnification consistent at different positions in the actual shot.

[0154] In summary, the drone lens provided by this utility model adopts a hybrid combination of one spherical glass, one aspherical glass, and six aspherical plastic pieces. Through specific surface shape settings and reasonable optical power distribution, the structure of the optical lens is relatively compact (TTL≤17mm), which can be adapted to 1 / 1.3” chips and has a field of view of 82°. It can achieve lightweight, high resolution, low distortion, and small purple fringing in drone lenses.

[0155] The above description merely illustrates several embodiments of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and this utility model also intends to include these modifications and variations.

Claims

1. A drone lens, characterized in that, Set sequentially from the object side to the image side along the lens optical axis: The first lens is a spherical glass lens with negative optical power, wherein the object side is convex and the image side is concave. The second lens is an aspherical plastic lens with negative optical power, which is a paraxial convex-concave lens. The third lens is an aspherical glass lens with positive optical power, and both its object side and image side are convex. Aperture stop; The fourth lens is an aspherical plastic lens with positive optical power, and both its object-side surface and image-side surface are convex. The fifth lens is an aspherical plastic lens with negative optical power, whose object side is convex and image side is concave. The sixth lens is an aspherical plastic lens with positive optical power, and it is a paraxial convex lens. The seventh lens is an aspherical plastic lens with negative optical power, which is a paraxial convex-concave lens; The eighth lens is an aspherical plastic lens with negative optical power, which is a paraxial convex-concave lens; A filter, wherein the filter is disposed on the image-side surface of the eighth lens; An imaging surface is disposed on the image-side surface of the filter.

2. The drone lens of claim 1, wherein: The lens satisfies the following relationship: IC / TTL≥0.73, where TTL is the total optical length of the lens and IC is the full-image height of the 1 / 1.3” chip paired with the lens.

3. The drone lens of claim 1, wherein: The lens satisfies the following relationship: TTL / f≤2.3, where f is the total focal length of the lens and TTL is the total optical length of the lens.

4. The drone lens of claim 1, wherein: The lens satisfies the following relationship: OBFL / TTL≥0.12, where TTL is the total optical length of the lens and OBFL is the optical back focal length of the lens.

5. The drone lens of claim 1, wherein: The lens satisfies the following condition: F#≤1.7, where F# is the aperture of the lens.

6. The drone lens of claim 1, wherein: The lens satisfies the following condition: f≤7.5mm, where f is the total focal length of the lens.

7. The drone lens of claim 1, wherein: The lens satisfies the following condition: TTL≤17mm, where TTL is the total optical length of the lens.

8. The drone lens of claim 1, wherein: The lens satisfies the following relationship: -3.04≤f1 / f≤-2.45, -2.21≤f² / f≤-1.81, 0.9≤f³ / f≤1.11 1.35≤f4 / f≤1.65 -5.65≤f5 / f≤-4.53, 4.49≤f6 / f≤5.49 -3.58≤f7 / f≤-2.93, -77.49≤f8 / f≤-63.4; In the formula, f is the total focal length of the lens, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, f6 is the focal length of the sixth lens, f7 is the focal length of the seventh lens, and f8 is the focal length of the eighth lens.

9. The drone lens according to claim 1, characterized in that: The aspherical surfaces of the second, third, fourth, fifth, sixth, seventh, and eighth lenses satisfy the following formula: In the formula, Z is the sag of the lens along the optical axis, k is the conic coefficient of the quadratic surface, γ is the lens height, c is the lens curvature, and A, B, C, D, E, F, and G are the coefficients of the 4th, 6th, 8th, 10th, 12th, 14th, and 16th order terms of the aspherical polynomial.

10. The drone lens of any one of claims 1 to 9, wherein: Also set along the lens optical axis: A filter, wherein the filter is disposed on the image-side surface of the eighth lens; An imaging surface is disposed on the image-side surface of the filter.

Images