A large aperture starlight-level drone lens

Abstract

The invention discloses a large aperture starlight-level drone lens, comprising a negative power first lens L1, a negative power second lens L2, a positive power third lens L3, a negative power fourth lens L4, a positive power fifth lens L5, a negative power sixth lens L6, a positive power seventh lens L7, a negative power eighth lens L8, a positive power ninth lens L9, a positive power tenth lens L10 and a positive power eleventh lens L11, which are sequentially arranged along the incident direction of light, each lens comprising at least one lens with a refractive index nd≥1.90; the third lens L3 and the fourth lens L4 are glued to form a first glued lens group, and the seventh lens L7, the eighth lens L8 and the ninth lens L9 are glued to form a second glued lens group. The lens can realize the athermal design and large aperture optical requirements, effectively balance chromatic aberration, avoid running focus, have high definition, and be small in size, and is suitable for drone-mounted and shooting under different light and temperature.

Description

Technical Field

[0001] The invention belongs to the field of optical lenses, and in particular relates to a large-aperture starlight-level drone lens. Background Art

[0002] As drone technology becomes more and more mature, it is low-cost, easy to operate and highly flexible, enabling it to carry some important equipment to complete special tasks from the air, such as aerial surveillance, aerial message relay, aerial shouting, emergency rescue, etc. When performing special tasks, it has strong survivability, good mobility, and is easy to use. It plays an important role in dealing with natural disasters, accidents, disasters, and social security incidents. In recent years, with the improvement of people's living standards, some consumer-grade drones have also appeared in people's daily lives, enriching their entertainment and spare time, but both professional and consumer-grade drones are inseparable from the camera lenses they carry.

[0003] At present, most consumer drones are equipped with cameras with fixed lenses, while professional drones are equipped with SLR or micro-single cameras. Some can carry medium-format cameras. Considering the load-bearing capacity of drones, it is generally not suitable to carry large and heavy constant aperture telephoto lenses. The lenses of micro-single, SLR, and medium-format cameras can only be used during the day. At night, the light is insufficient and the shooting effect is very unsatisfactory. The infrared light has a limited irradiation distance, and the shooting is still unsatisfactory. Therefore, how to make drones take clear pictures at night and make the use of drones unlimited is an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present invention is to propose a large-aperture starlight-level drone lens in response to the above-mentioned problems, which solves the problem of back focus shift caused by temperature changes, realizes a heat-free design, meets the optical requirements of a large target surface and a large aperture, effectively optimizes and balances chromatic aberration, has good night photography effects, high clarity, and a small size, and is suitable for drone mounting and shooting under different light and temperature conditions.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a large aperture starlight-class drone lens, comprising a first lens L1 with negative focal power, a second lens L2 with negative focal power, a third lens L3 with positive focal power, a fourth lens L4 with negative focal power, a fifth lens L5 with positive focal power, a sixth lens L6 with negative focal power, a seventh lens L7 with positive focal power, an eighth lens L8 with negative focal power, a ninth lens L9 with positive focal power, a tenth lens L10 with positive focal power, and an eleventh lens L11 with positive focal power, which are sequentially arranged along the incident direction of light, wherein:

[0007] Each lens includes at least one lens satisfying the condition of a refractive index nd≥1.90;

[0008] The third lens L3 and the fourth lens L4 are glued together to form a first glued lens group, and the seventh lens L7, the eighth lens L8 and the ninth lens L9 are glued together to form a second glued lens group.

[0009] Preferably, the first lens L1 and the sixth lens L6 are convex-concave lenses;

[0010] The second lens L2 and the eighth lens L8 are biconcave lenses;

[0011] The third lens L3, the fifth lens L5, the seventh lens L7, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are biconvex lenses;

[0012] The fourth lens L4 is a crescent-shaped lens.

[0013] Preferably, 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, the eighth lens L8, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are all spherical glass lenses.

[0014] Preferably, the large aperture starlight-level drone lens meets the following conditions:

[0015] 0.29≤f2 / f1≤0.6

[0016] Wherein, f1 is the focal length value of the first lens L1, and f2 is the focal length value of the second lens L2.

[0017] Preferably, the large aperture starlight-level drone lens meets the following conditions:

[0018] 0.85≤f11 / f10≤0.92

[0019] Wherein, f10 is the focal length value of the tenth lens L10, and f11 is the focal length value of the eleventh lens L11.

[0020] Preferably, at least one lens satisfying the condition of a refractive index nd ≥ 1.90 is located in the first cemented lens group or the second cemented lens group.

[0021] Preferably, the refractive index nd of the fourth lens L4, the eighth lens L8 and the tenth lens L10 is ≥ 1.90.

[0022] Preferably, an adjustable aperture STO is arranged between the sixth lens L6 and the seventh lens L7.

[0023] Preferably, the maximum aperture number of the large aperture starlight-level drone lens can reach 1.0.

[0024] Preferably, a filter IRCUT is provided on a side of the eleventh lens L11 close to the image plane S1.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The use of high refractive index lenses and the distribution of focal lengths of positive and negative lenses solves the problem of back focus shifting due to temperature changes, realizes athermal design, and can work in a variety of temperature environments;

[0027] 2) Use multiple glued lens groups to effectively optimize and balance chromatic aberration and improve imaging effects;

[0028] 3) This structure can achieve the optical requirements of large target area and large aperture, effectively correct aberrations, have good night photography effects, high clarity and small size, and is suitable for drone mounting and shooting under different lighting conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 This is an MTF diagram of Example 1 of the present invention;

[0031] Figure 3 The astigmatism and distortion diagram of the first embodiment of the present invention;

[0032] Figure 4 This is the MTF diagram of the second embodiment of the present invention;

[0033] Figure 5 This is an astigmatism and distortion diagram of the second embodiment of the present invention;

[0034] Figure 6 This is the MTF diagram of the third embodiment of the present invention;

[0035] Figure 7 This is an astigmatism and distortion diagram of Example 3 of the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The following embodiments do not constitute a limitation of the present invention.

[0037] The symbols used in the present application specification are defined as follows: F# is the aperture number, DFOV is the maximum oblique field angle of the lens, in degrees, f1 is the focal length of the first lens L1, in mm, f2 is the focal length of the second lens L2, in mm, f10 is the focal length of the tenth lens L10, in mm, f11 is the focal length of the eleventh lens L11, in mm, f is the focal length of the lens, in mm, R is the radius of curvature, in mm, D is the thickness of the lens or the thickness of the air, in mm, nd is the refractive index, and vd is the Abbe number; the mirror surfaces of each lens are numbered in sequence from the direction of incident light (i.e., from the object plane to the image plane S1), L1R1 is the first surface of the first lens L1, L1R2 is the second surface of the first lens L1, L2R1 is the first surface of the second lens L2, L2R2 is the second surface of the second lens L2, L3R1 is the first surface of the third lens L3, L3 R2 is the second surface of the third lens L3, L4R1 is the first surface of the fourth lens L4, L4R2 is the second surface of the fourth lens L4, L5R1 is the first surface of the fifth lens L5, L5R2 is the second surface of the fifth lens L5, L6R1 is the first surface of the sixth lens L6, L6R2 is the second surface of the sixth lens L6, L7R1 is the first surface of the seventh lens L7, L7R2 is the second surface of the seventh lens L7, L8R1 is the first surface of the eighth lens L8, L8R2 is the second surface of the eighth lens L8, L9R1 is the first surface of the ninth lens L9, L9R2 is the second surface of the ninth lens L9, L10R1 is the first surface of the tenth lens L10, L10R2 is the second surface of the tenth lens L10, L11R1 is the first surface of the eleventh lens L11, and L11R2 is the second surface of the eleventh lens L11.

[0038] Embodiment 1:

[0039] like Figure 1-3 As shown, a large aperture starlight-class drone lens comprises a first lens L1 with negative focal power, a second lens L2 with negative focal power, a third lens L3 with positive focal power, a fourth lens L4 with negative focal power, a fifth lens L5 with positive focal power, a sixth lens L6 with negative focal power, a seventh lens L7 with positive focal power, an eighth lens L8 with negative focal power, a ninth lens L9 with positive focal power, a tenth lens L10 with positive focal power, and an eleventh lens L11 with positive focal power, which are sequentially arranged along the incident direction of light, wherein:

[0040] Each lens includes at least one lens that satisfies the condition of a refractive index nd≥1.90;

[0041] The third lens L3 and the fourth lens L4 are glued together to form a first glued lens group, and the seventh lens L7, the eighth lens L8 and the ninth lens L9 are glued together to form a second glued lens group.

[0042] In one embodiment, the first lens L1 and the sixth lens L6 are convex-concave lenses;

[0043] The second lens L2 and the eighth lens L8 are biconcave lenses;

[0044] The third lens L3, the fifth lens L5, the seventh lens L7, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are biconvex lenses;

[0045] The fourth lens L4 is a crescent-shaped lens.

[0046] Among them, when the light is incident, the eleven lenses along the lens adjust the incident angle of the light in sequence to meet the requirements of low-light shooting and imaging quality. The first lens L1 collects the large-angle light into the lens, the second lens L2 adjusts the light propagation angle, the third lens L3 and the fourth lens L4 are glued together to form a first glued lens group for correcting chromatic aberration, the fifth lens L5 is responsible for adjusting the light angle to assist in aberration correction, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are glued together to form a second glued lens group for further correcting chromatic aberration, and the adjacent surfaces of the tenth lens L10 and the eleventh lens L11 are designed to diverge, that is, L10R2 is curved toward the object plane, and L11R1 is curved toward the image plane, which can further correct aberrations, especially spherical aberration, astigmatism and field curvature.

[0047] Each glued lens group is bonded with photosensitive glue, such as UV glue, to correct the chromatic aberration of light of different wavelengths, and the dispersion of each lens can be compensated, so as to minimize the comprehensive chromatic aberration. The lens uses at least one lens with a high refractive index nd≥1.90 and distributes the focal length of the positive and negative lenses, which can avoid the back focus shift caused by temperature changes, effectively optimize and balance chromatic aberration, improve imaging effects, and achieve the optical requirements of large target surface and large aperture. It has good night photography effect, high clarity and small size, and is suitable for drones and different temperature and light conditions.

[0048] In one embodiment, 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, the eighth lens L8, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are all spherical glass lenses.

[0049] Among them, each lens is a spherical glass lens, which is easy to shape and wear-resistant, has a low mold cost and a long service life. Aspherical lenses can also be used to further reduce the weight and length of the lens and improve the imaging quality of the lens. Alternatively, each lens can be made of plastic material to reduce the weight of the lens, which can significantly reduce costs when produced in large quantities.

[0050] In one embodiment, a large aperture starlight-level drone lens satisfies the following conditions:

[0051] 0.29≤f2 / f1≤0.6

[0052] Wherein, f1 is the focal length value of the first lens L1, and f2 is the focal length value of the second lens L2.

[0053] Among them, the first lens L1 collects large-angle light into the lens, and the second lens L2 adjusts the light propagation angle, controlling the size of the lens to meet 0.29≤f2 / f1≤0.6. The optical focal length of the first lens L1 and the second lens L2 is reasonably allocated, which is more conducive to adjusting the light angle to achieve miniaturization of the lens and is suitable for drone mounting.

[0054] In one embodiment, a large aperture starlight-level drone lens satisfies the following conditions:

[0055] 0.85≤f11 / f10≤0.92

[0056] Wherein, f10 is the focal length value of the tenth lens L10, and f11 is the focal length value of the eleventh lens L11.

[0057] Among them, the tenth lens L10 and the eleventh lens L11 can further correct aberrations, especially spherical aberration, astigmatism and field curvature, and improve imaging quality under the condition of 0.85≤f11 / f10≤0.92.

[0058] In one embodiment, at least one lens satisfying the condition of a refractive index nd ≥ 1.90 is located in the first cemented lens group or the second cemented lens group.

[0059] Among them, the lens with a refractive index nd≥1.90 is preferably located in the first cemented lens group or the second cemented lens group, and the imaging effect is good. Any number or any lens arrangement can be selected. It should be noted that the lens with a refractive index nd≥1.90 can also be any one or more of the 11 lenses in the lens.

[0060] In this embodiment, the refractive index nd of the fourth lens L4, the eighth lens L8 and the tenth lens L10 is ≥1.90.

[0061] Among them, the refractive index nd of the fourth lens L4 in the first cemented lens group, the eighth lens L8 and the tenth lens L10 in the second cemented lens group is ≥1.90, which helps to reduce the thickness of the lenses and facilitates clear imaging.

[0062] In one embodiment, an adjustable aperture STO is disposed between the sixth lens L6 and the seventh lens L7.

[0063] Among them, the adjustable aperture STO is placed between the sixth lens L6 and the seventh lens L7. When the aperture is opened to the maximum, a large amount of light enters, so that a good photo effect can be achieved at night, and the exposure phenomenon can be avoided when there is sufficient light by adjusting the aperture.

[0064] In one embodiment, the maximum aperture number of the large aperture starlight-level drone lens can reach 1.0.

[0065] Among them, the aperture number of this lens can achieve a large aperture of 1.0, which is suitable for use in dim or low-light environments. It can capture more light in dark environments and greatly improve the imaging quality.

[0066] In one embodiment, a filter IRCUT is disposed on a side of the eleventh lens L11 close to the image plane S1.

[0067] The filter IRCUT can automatically switch according to the strength of the external light to achieve the best image effect. It is a conventional technology well known to those skilled in the art and will not be described here. It can be used to correct the color cast problem during the day and improve the brightness at night, so that the best imaging effect can be obtained regardless of day or night. It can also be used to protect the lens and image surface.

[0068] Furthermore, the optical parameters of each mirror and filter IRCUT in this embodiment are as follows:

[0069]

[0070]

[0071] The lens related parameters in this embodiment are as follows:

[0072] F# DFOV f1 f2 f10 f11 f2 / f1 f11 / f10 1.0 105° -17.86 -8.4 24.19 21.59 0.47 0.89

[0073] Based on the above table data, Figure 2 As shown, when the aperture is opened to the maximum, that is, F#=1.0, at a spatial frequency of 80lp / mm, the full field of view MTF>0.45, with high resolution and high definition quality. Figure 3 As shown in the figure, astigmatism and field curvature are controlled within 0.05mm, distortion is small, and all lens parameter indicators under large aperture conditions are met. The field of view angle can reach greater than or equal to 100°, the target surface can reach 1 / 1.8", the aperture is adjustable, the maximum aperture can reach 1.0, and the resolution can reach 6 million, which can achieve low-light shooting and obtain clear images.

[0074] Embodiment 2:

[0075] like Figure 1 , 4 As shown in , this embodiment is based on the design of the large aperture starlight-level drone lens in embodiment 1, with the following differences:

[0076] The optical parameters of each mirror and filter IRCUT in this embodiment are as follows:

[0077]

[0078] The lens related parameters in this embodiment are as follows:

[0079] F# DFOV f1 f2 f10 f11 f2 / f1 f11 / f10 1.0 105° -13.52 -8.11 21.36 19.65 0.599 0.919

[0080] Based on the above table data, Figure 4 As shown, when the aperture is opened to the maximum, that is, F#=1.0, at a spatial frequency of 80lp / mm, the full field of view MTF>0.45, with high resolution and high definition quality. Figure 5 As shown in the figure, astigmatism and field curvature are controlled within 0.05mm, distortion is small, and all lens parameter indicators under large aperture conditions are met. The field of view angle can reach greater than or equal to 100°, the target surface can reach 1 / 1.8", the aperture is adjustable, the maximum aperture can reach 1.0, and the resolution can reach 6 million, which can achieve low-light shooting and obtain clear images.

[0081] Embodiment 3:

[0082] like Figure 1 , 6 As shown in 7, this embodiment is based on the design of the large aperture starlight-level drone lens in embodiment 1, with the following differences:

[0083] The optical parameters of each mirror and filter IRCUT in this embodiment are as follows:

[0084]

[0085] The lens related parameters in this embodiment are as follows:

[0086] F# DFOV f1 f2 f10 f11 f2 / f1 f11 / f10 1.0 105° -19.96 -5.78 26.52 22.54 0.29 0.85

[0087] Based on the above table data, Figure 6 As shown, when the aperture is opened to the maximum, that is, F#=1.0, at a spatial frequency of 80lp / mm, the full field of view MTF>0.45, with high resolution and high definition quality. Figure 7 As shown in the figure, astigmatism and field curvature are controlled within 0.05mm, distortion is small, and all lens parameter indicators under large aperture conditions are met. The field of view angle can reach greater than or equal to 100°, the target surface can reach 1 / 1.8", the aperture is adjustable, the maximum aperture can reach 1.0, and the resolution can reach 6 million, which can achieve low-light shooting and obtain clear images.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Without departing from the spirit and essence of the present invention, technicians familiar with the field can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims attached to the present invention.

Claims

1. A large aperture starlight-level drone lens, Features: The large aperture starlight-class drone lens is composed of a first lens L1 with negative focal power, a second lens L2 with negative focal power, a third lens L3 with positive focal power, a fourth lens L4 with negative focal power, a fifth lens L5 with positive focal power, a sixth lens L6 with negative focal power, a seventh lens L7 with positive focal power, an eighth lens L8 with negative focal power, a ninth lens L9 with positive focal power, a tenth lens L10 with positive focal power, and an eleventh lens L11 with positive focal power, which are arranged in sequence along the incident direction of light, wherein: Each of the lenses includes at least one lens that satisfies the condition of a refractive index nd≥1.90; The third lens L3 and the fourth lens L4 are glued together to form a first glued lens group, and the seventh lens L7, the eighth lens L8 and the ninth lens L9 are glued together to form a second glued lens group; The first lens L1 and the sixth lens L6 are convex-concave lenses; The second lens L2 and the eighth lens L8 are biconcave lenses; The third lens L3, the fifth lens L5, the seventh lens L7, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are biconvex lenses; The fourth lens L4 is a crescent-shaped lens; The large aperture starlight-level drone lens meets the following conditions: 0.29≤f2 / f1≤0.6, 0.85≤f11 / f10≤0.92 Among them, f1 is the focal length value of the first lens L1, f2 is the focal length value of the second lens L2, f10 is the focal length value of the tenth lens L10, and f11 is the focal length value of the eleventh lens L11.

2. The large aperture starlight-class drone lens as claimed in claim 1, Features: 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, the eighth lens L8, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are all spherical glass lenses.

3. The large aperture starlight-level drone lens as claimed in claim 1, Features: The lens satisfying the condition of refractive index nd≥1.90 is located in the first glued lens group or the second glued lens group.

4. The large aperture starlight-class drone lens as claimed in claim 3, Features: The refractive index nd of the fourth lens L4, the eighth lens L8 and the tenth lens L10 is ≥1.

90.

5. The large aperture starlight-class drone lens as claimed in claim 1, Features: An adjustable aperture STO is arranged between the sixth lens L6 and the seventh lens L7.

6. The large aperture starlight-class drone lens as claimed in claim 1, Features: The maximum aperture number of the large aperture starlight-level drone lens can reach 1.

0.

7. The large aperture starlight-level drone lens as claimed in claim 1, Features: A filter IRCUT is disposed on a side of the eleventh lens L11 close to the image plane S1.

Images