An underwater white low-light detection lens, mechanical packaging structure, and underwater camera instrument
By designing a white low-light large field-of-view detection lens suitable for underwater applications, the problems of insufficient light transmission and poor stability of underwater lenses under low illumination conditions have been solved. This enables the switching between large-area detection and small-area identification imaging, resulting in clear imaging, a large field of view, and excellent aberration correction, making it suitable for underwater detection and photography.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU UNIV
- Filing Date
- 2026-04-14
- Publication Date
- 2026-05-26
AI Technical Summary
Existing underwater lenses have insufficient light transmission under low light conditions, resulting in poor image quality. They cannot simultaneously handle large-scale monitoring and small-scale identification, and their stability in underwater environments is poor, with inadequate aberration correction.
An underwater white low-light wide-field detection lens was designed. It adopts a single-lens imaging method and features ultra-wide-angle, zoom, and large-aperture capabilities. The lens material and structural design are adapted to the underwater environment. The lens shell is made of 6063 aluminum alloy, and the lenses are fixed securely. The inside of the lens barrel is coated with an anti-light material. The lens material and structure have been optimized to improve image quality.
It enables imaging switching between large-scale detection and small-scale identification in low-light underwater environments, with clear imaging, a field of view of up to 120°, stable lenses, and excellent aberration correction, making it suitable for underwater detection and photography.
Smart Images
Figure CN122085495A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optical lens technology, and in particular to an underwater white low-light detection lens. Background Technology
[0002] With the deepening development of marine resource development, underwater archaeology, underwater search and rescue, and military reconnaissance, the requirements for underwater optical detection equipment are increasing. The underwater environment is complex, with severe light attenuation, especially at greater depths or in turbid water, where ambient illumination is extremely low, a typical "white low-light" environment. Existing underwater lenses generally suffer from the following problems: First, they are functionally limited, unable to simultaneously handle large-scale monitoring and detection with precise identification in small areas; second, under low-light conditions, the aperture is small, resulting in insufficient light transmission, leading to low image brightness and high noise; third, some lenses use plastic lenses, which have poor stability in underwater environments with varying temperatures and pressures, easily affecting image quality; fourth, the optical design does not fully consider the special characteristics of underwater applications, resulting in poor aberration correction and poor edge imaging quality. Summary of the Invention
[0003] This invention provides an underwater white low-light wide field-of-view detection lens, which has an ultra-wide angle (120°), a large aperture (F number 1.3), zoom function (focal length 3mm and 6mm) and near-infrared extension capability (wavelength up to 1000nm), and is suitable for high-quality imaging in underwater low-light environments.
[0004] This invention uses a single-lens imaging method to achieve an ultra-wide field of view and zoom function, which has higher structural integrity and reliability compared to multi-lens stitching schemes.
[0005] The lenses are arranged sequentially from the object side to the image side, numbered from first to twelfth. All lens surfaces are spherical. The medium on the object side of the system is water, meaning the object-side refractive index is the refractive index of water.
[0006] The first lens is a meniscus lens, with a convex surface facing the object plane, a thickness of 1.32 mm, a refractive index of 1.52, and an Abbe number of 62.2;
[0007] The second lens is a meniscus lens, with a convex surface facing the object plane, a thickness of 2.8 mm, a refractive index of 1.50, and an Abbe number of 65.4.
[0008] The third lens is a meniscus lens with a convex surface facing the image plane, a thickness of 2.84 mm, a refractive index of 1.49, and an Abbe number of 67.1.
[0009] The fourth lens is a biconvex lens with a thickness of 13.11 mm, a refractive index of 1.75, and an Abbe number of 28.9.
[0010] The fifth lens is a meniscus lens with a convex surface facing the object plane, a thickness of 4.97 mm, a refractive index of 1.55, and an Abbe number of 45.9.
[0011] The sixth lens is a biconvex lens, with one side of its object plane being approximately flat. It has a thickness of 8.24 mm, a refractive index of 1.72, and an Abbe number of 46.4.
[0012] An aperture stop is provided behind the sixth lens, with a thickness of 0.1 mm at a focal length of 3 mm and a thickness of 0.15 mm at a focal length of 6 mm.
[0013] The seventh lens is a biconvex lens, with one side of its object plane being approximately flat. It has a thickness of 5.31 mm, a refractive index of 1.63, and an Abbe number of 58.2.
[0014] The eighth lens is a meniscus lens with a concave surface facing the object plane, a thickness of 2.8 mm, a refractive index of 1.76, and an Abbe number of 27.5.
[0015] The ninth lens is a biconvex lens with a thickness of 6.38 mm, a refractive index of 1.64, and an Abbe number of 53.2.
[0016] The tenth lens is a meniscus lens with a concave surface facing the object plane, a thickness of 2.8 mm, a refractive index of 1.75, and an Abbe number of 28.0.
[0017] The eleventh lens is a biconvex lens with a thickness of 5.18 mm, a refractive index of 1.61, and an Abbe number of 53.9.
[0018] The twelfth lens is a meniscus lens with a convex surface facing the image plane, a thickness of 2.8 mm, a refractive index of 1.76, and an Abbe number of 27.5.
[0019] Furthermore, the radii of curvature of each mirror are as follows:
[0020] The front surface radius of the first lens is 90.02 mm, and the rear surface radius is 1.32 mm.
[0021] The second lens has a front surface radius of 42.22 mm and a rear surface radius of 2.8 mm.
[0022] The third lens has a front surface radius of -19.33 mm and a rear surface radius of 2.84 mm.
[0023] The fourth lens has a front surface radius of 34.59 mm and a rear surface radius of 13.11 mm.
[0024] The fifth lens has a front surface radius of 210.73 mm and a rear surface radius of 4.97 mm.
[0025] The sixth lens has a front surface radius of 78.64 mm and a rear surface radius of 8.24 mm.
[0026] The seventh lens has a front surface radius of 60.38 mm and a rear surface radius of 5.31 mm.
[0027] The eighth lens has a front surface radius of -16.15 mm and a rear surface radius of 2.8 mm.
[0028] The ninth lens has a front surface radius of 32.65 mm and a rear surface radius of 6.38 mm.
[0029] The tenth lens has a front surface radius of -16.04 mm and a rear surface radius of 2.8 mm.
[0030] The eleventh lens has a front surface radius of 20.20 mm and a rear surface radius of 5.18 mm.
[0031] The twelfth lens has a front surface radius of -29.00 mm and a rear surface radius of 2.8 mm.
[0032] The specific materials selected for each of the above lenses are as follows:
[0033] The first lens is made of H-K11 glass;
[0034] The second lens is made of H-K9L glass;
[0035] The third lens is made of H-FK61 glass;
[0036] The fourth lens is made of H-ZF7L glass;
[0037] The fifth lens is made of H-KF6 glass;
[0038] The sixth lens is made of H-LaK6 glass;
[0039] The seventh lens is made of glass of model D-ZK21;
[0040] The eighth lens is made of H-ZF52 glass;
[0041] The ninth lens is made of H-ZK10 glass;
[0042] The tenth lens is made of H-ZF52 glass;
[0043] The eleventh lens is made of H-ZK10 glass;
[0044] The twelfth lens is made of H-ZF52 glass;
[0045] Furthermore, the lens operates in the 400nm to 1000nm wavelength range.
[0046] Furthermore, the lens has an F-number of 1.3.
[0047] Furthermore, the focal length of the lens is zoom, with a zoom range of 3mm-6mm.
[0048] Furthermore, the lens barrel outside the lens is a mechanical assembly. The lens is encapsulated within a 6063 aluminum alloy lens barrel housing. The inside of the lens barrel is coated with an anti-light-reducing material to minimize stray light. 6063 aluminum alloy spacers are used inside the lens barrel to secure the lens elements. The eleventh and twelfth lenses are fixed to the lens barrel, while the other lenses are movably connected to the lens barrel, allowing them to move within the barrel. During movement, the following relative fixations are maintained: between the first and second lenses, between the third and fourth lenses, between the fifth and sixth lenses, between the seventh and eighth lenses, and between the ninth and tenth lenses.
[0049] Optionally, this lens can be used with an external light source for supplemental lighting, preferably with an operating wavelength covering the 400-1000nm band.
[0050] This detection lens has excellent optical performance and can achieve underwater low-light, low-light, wide field of view, and zoom imaging.
[0051] Based on the aforementioned lens, the present invention also proposes an underwater camera device, which is equipped with the aforementioned lens.
[0052] The beneficial effects of this invention are:
[0053] (1) This lens achieves continuous zoom in the 3mm-6mm focal length range, and can continuously switch between imaging functions of large-scale detection and small-scale precise identification.
[0054] (2) Large aperture low-light imaging. With an F number of 1.3 and a working wavelength extended to 1000nm, it can obtain clear images in low-light underwater environments, and is particularly suitable for detection in special low-light underwater environments.
[0055] (3) Ultra-wide field of view. The field of view of this invention is over 120°, far exceeding that of traditional underwater lenses, enabling wide-area underwater detection in low light conditions and significantly improving the monitoring range.
[0056] (4) Underwater Adaptation Design. With water as the surface medium, the system directly considers the refractive index of water, avoiding aberration degradation caused by refractive index mismatch when using traditional lenses underwater. In particular, it corrects various aberrations, especially distortion and chromatic aberration, precisely achieving excellent imaging performance. The lens has a compact overall structure, with each lens element securely fitted to the lens barrel and spacers, exhibiting high environmental adaptability and suitable for underwater exploration, underwater photography, and other fields. Attached Figure Description
[0057] Figure 1 This is a schematic diagram of the structure when the lens focal length is 3mm;
[0058] Figure 2 This is a schematic diagram of the structure when the lens focal length is 6mm;
[0059] Figure 3 This is the MTF chart when the lens focal length is 3mm;
[0060] Figure 4 This is the MTF chart when the lens focal length is 6mm;
[0061] Figure 5 It is a light difference curve when the lens focal length is 3mm;
[0062] Figure 6 It is a light difference curve when the lens focal length is 6mm;
[0063] Figure 7 This is the field curvature diagram when the lens focal length is 3mm;
[0064] Figure 8 This is a field curvature diagram when the lens focal length is 6mm. Detailed Implementation
[0065] The present invention will now be described in further detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0066] Figure 1 and Figure 2 The diagram shown is a schematic of a lens provided in Embodiment 1 of the present invention. The lenses are arranged from the object side to the image side as a first lens, a second lens, ..., up to a twelfth lens.
[0067] The first lens is a meniscus lens, with a convex surface facing the object plane, a thickness of 1.32 mm, a refractive index of 1.52, and an Abbe number of 62.2;
[0068] The second lens is a meniscus lens, with a convex surface facing the object plane, a thickness of 2.8 mm, a refractive index of 1.50, and an Abbe number of 65.4.
[0069] The third lens is a meniscus lens with a convex surface facing the image plane, a thickness of 2.84 mm, a refractive index of 1.49, and an Abbe number of 67.1.
[0070] The fourth lens is a biconvex lens with a thickness of 13.11 mm, a refractive index of 1.75, and an Abbe number of 28.9.
[0071] The fifth lens is a meniscus lens with a convex surface facing the object plane, a thickness of 4.97 mm, a refractive index of 1.55, and an Abbe number of 45.9.
[0072] The sixth lens is a biconvex lens, with one side of its object plane being approximately flat. It has a thickness of 8.24 mm, a refractive index of 1.72, and an Abbe number of 46.4.
[0073] An aperture stop is provided behind the sixth lens, with a thickness of 0.1 mm at a focal length of 3 mm and a thickness of 0.15 mm at a focal length of 6 mm.
[0074] The seventh lens is a biconvex lens, with one side of its object plane being approximately flat. It has a thickness of 5.31 mm, a refractive index of 1.63, and an Abbe number of 58.2.
[0075] The eighth lens is a meniscus lens with a concave surface facing the object plane, a thickness of 2.8 mm, a refractive index of 1.76, and an Abbe number of 27.5.
[0076] The ninth lens is a biconvex lens with a thickness of 6.38 mm, a refractive index of 1.64, and an Abbe number of 53.2.
[0077] The tenth lens is a meniscus lens with a concave surface facing the object plane, a thickness of 2.8 mm, a refractive index of 1.75, and an Abbe number of 28.0.
[0078] The eleventh lens is a biconvex lens with a thickness of 5.18 mm, a refractive index of 1.61, and an Abbe number of 53.9.
[0079] The twelfth lens is a meniscus lens with a convex surface facing the image plane, a thickness of 2.8 mm, a refractive index of 1.76, and an Abbe number of 27.5.
[0080] Furthermore, the radii of curvature of each mirror are as follows:
[0081] The front surface radius of the first lens is 90.02 mm, and the rear surface radius is 1.32 mm.
[0082] The second lens has a front surface radius of 42.22 mm and a rear surface radius of 2.8 mm.
[0083] The third lens has a front surface radius of -19.33 mm and a rear surface radius of 2.84 mm.
[0084] The fourth lens has a front surface radius of 34.59 mm and a rear surface radius of 13.11 mm.
[0085] The fifth lens has a front surface radius of 210.73 mm and a rear surface radius of 4.97 mm.
[0086] The sixth lens has a front surface radius of 78.64 mm and a rear surface radius of 8.24 mm.
[0087] The seventh lens has a front surface radius of 60.38 mm and a rear surface radius of 5.31 mm.
[0088] The eighth lens has a front surface radius of -16.15 mm and a rear surface radius of 2.8 mm.
[0089] The ninth lens has a front surface radius of 32.65 mm and a rear surface radius of 6.38 mm.
[0090] The tenth lens has a front surface radius of -16.04 mm and a rear surface radius of 2.8 mm.
[0091] The eleventh lens has a front surface radius of 20.20 mm and a rear surface radius of 5.18 mm.
[0092] The twelfth lens has a front surface radius of -29.00 mm and a rear surface radius of 2.8 mm.
[0093] The following provides examples of lens parameters provided in embodiments of the present invention.
[0094] Example 1:
[0095] In the specific implementation process, when the focal length is 3mm, the radius of curvature R, center thickness Tc, refractive index Nd, and Abbe constant Vd of each lens of the lens satisfy the conditions listed in Table 1.
[0096] Table 1
[0097] Surface number Surface name Curvature C (unit: mm⁻¹) Center thickness Tc (unit: mm) Refractive index Nd Abbe number Vd surface unlimited unlimited 1.33 52.8 1 lens1 90.02 1.32 1.52 62.2 2 12.93 7.56 1 0 3 lens2 42.22 2.8 1.5 65.4 4 13.8 7.94 1 0 5 lens3 -19.33 2.83 1.49 67.1 6 241.91 0.1 1 0 7 lens4 34.59 13.11 1.75 28.9 8 -95.2 53.33 1 0 9 lens5 210.73 4.97 1.55 45.9 10 22.79 1.38 1 0 11 lens6 78.64 8.24 1.72 46.4 12 -33.97 12.98 1 0 aperture unlimited 0.1 1 0 14 lens7 60.38 5.31 1.63 58.2 15 -18.8 1.07 1 0 16 lens8 -16.15 2.8 1.76 27.5 17 189.03 7.75 1 0 18 lens9 32.65 6.39 1.64 53.2 19 -16.71 0.32 1 0 20 lens10 -16.03 2.8 1.75 28.0 21 -24.88 0.1 1 0 22 lens11 20.20 5.18 1.61 53.9 23 -36 0.19 1 0 24 lens12 -28.99 2.8 1.76 27.5 25 -397.49 9.4 1 0 Image unlimited 0.01
[0098] In zoom mode (focal length 6mm), only the thickness of the lower surface changes:
[0099] Surface number Center thickness Tc (unit: mm) 4 8.64 8 0.12 aperture 0.15 17 0.1 21 6.23
[0100] Based on the refractive index and Abbe number of the lenses in Example 1, the materials selected for each lens are as follows:
[0101] The first lens is made of H-K11 glass;
[0102] The second lens is made of H-K9L glass;
[0103] The third lens is made of H-FK61 glass;
[0104] The fourth lens is made of H-ZF7L glass;
[0105] The fifth lens is made of H-KF6 glass;
[0106] The sixth lens is made of H-LaK6 glass;
[0107] The seventh lens is made of glass of model D-ZK21;
[0108] The eighth lens is made of H-ZF52 glass;
[0109] The ninth lens is made of H-ZK10 glass;
[0110] The tenth lens is made of H-ZF52 glass;
[0111] The eleventh lens is made of H-ZK10 glass;
[0112] The twelfth lens is made of H-ZF52 glass;
[0113] according to Figures 3-4 As shown, the MTF reached 0.3, indicating good image quality.
[0114] See Figure 5 and Figure 6 As shown in the lens light aberration curve, from a 1.0 field of view (40° full field of view) to a 0.00 field of view (on-axis), the light deviation is strictly controlled within a very small range (within ±0.038) in both the meridional and sagittal directions. This indicates that the lens exhibits excellent consistency and stability in imaging across the entire field of view from the center to the edge, without any issues such as edge blurring or distortion. The curves of different colors highly overlap with almost no obvious separation, indicating that the lens has a highly consistent focusing ability for different wavelengths of light, effectively avoiding color fringing and other color artifacts in the image, resulting in very pure and accurate color reproduction.
[0115] Figure 7 and Figure 8As shown in the lens field curve, the distortion values in the distortion curve on the left side are almost all concentrated near the zero point from 0° to 40° across the entire field of view. The curve is almost vertical, indicating that the distortion across the entire field of view is controlled to the extreme, and the image will not exhibit pincushion or barrel distortion, resulting in a realistic and natural image.
[0116] In the astigmatism and field curvature curve in the middle, the curves in the meridional and sagittal directions are highly coincident and the overall deviation is very small, indicating that the lens is well corrected for astigmatism and field curvature in the full field of view. The image surface from the center to the edge is flat and consistent, and there will be no problems such as edge blurring or focus shift.
[0117] In the longitudinal spherical aberration curve on the right, the curves of different wavelengths converge highly in the paraxial region, and the overall deviation range is very small. This indicates that the lens has a highly consistent focusing ability for incident light at different heights, effectively avoiding image blur caused by spherical aberration and exhibiting extremely strong detail reproduction capability.
[0118] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent methods or modifications that do not depart from the technology of the present invention should be included within the scope of protection of the present invention.
Claims
1. An underwater white low-light detection lens, characterized in that, From the object side to the image side, the lenses are arranged in order from the first lens to the twelfth lens; The first lens is a meniscus lens, and the side facing the object surface is convex. The second lens is a meniscus lens, with its side facing the object surface being convex. The third lens is a meniscus lens, with its side facing the image plane being convex. The fourth lens is a biconvex lens; The fifth lens is a meniscus lens, with its side facing the object surface being convex. The sixth lens is a biconvex lens, with one side of its object plane being approximately flat. An aperture is installed after the sixth lens; The seventh lens is a biconvex lens, and its object-plane side is approximately flat. The eighth lens is a meniscus lens, with its side facing the object surface being concave. The ninth lens is a biconvex lens; The tenth lens is a meniscus lens, with its side facing the object surface being concave. The eleventh lens is a biconvex lens; The twelfth lens is a meniscus lens, with its image-facing side being convex.
2. The underwater white light detection lens according to claim 1, characterized in that, The first lens has a thickness of 1.32 mm, a refractive index of 1.52, and an Abbe number of 62.
2. The second lens has a thickness of 2.8 mm, a refractive index of 1.50, and an Abbe number of 65.
4. The third lens has a power of 2.84 mm, a refractive index of 1.49, and an Abbe number of 67.
1. The fourth lens has a thickness of 13.11 mm, a refractive index of 1.75, and an Abbe number of 28.
9. The fifth lens has a thickness of 4.97 mm, a refractive index of 1.55, and an Abbe number of 45.
9. The sixth lens has a thickness of 8.24 mm, a refractive index of 1.72, and an Abbe number of 46.
4. The seventh lens has a thickness of 0.1 mm at a focal length of 3 mm and a thickness of 0.15 mm at a focal length of 6 mm. The eighth lens has a thickness of 2.8 mm, a refractive index of 1.76, and an Abbe number of 27.
5. The ninth lens has a thickness of 6.38 mm, a refractive index of 1.64, and an Abbe number of 53.
2. The tenth lens has a thickness of 2.8 mm, a refractive index of 1.75, and an Abbe number of 28.
0. The eleventh lens has a thickness of 5.18 mm, a refractive index of 1.61, and an Abbe number of 53.
9. The twelfth lens has a thickness of 2.8 mm, a refractive index of 1.76, and an Abbe number of 27.
5.
3. The underwater white light detection lens according to claim 2, characterized in that, The radii of curvature of each lens are as follows: The front surface radius of the first lens is 90.02 mm, and the rear surface radius is 1.32 mm. The second lens has a front surface radius of 42.22 mm and a rear surface radius of 2.8 mm. The third lens has a front surface radius of -19.33 mm and a rear surface radius of 2.84 mm. The fourth lens has a front surface radius of 34.59 mm and a rear surface radius of 13.11 mm. The fifth lens has a front surface radius of 210.73 mm and a rear surface radius of 4.97 mm. The sixth lens has a front surface radius of 78.64 mm and a rear surface radius of 8.24 mm. The seventh lens has a front surface radius of 60.38 mm and a rear surface radius of 5.31 mm. The eighth lens has a front surface radius of -16.15 mm and a rear surface radius of 2.8 mm. The ninth lens has a front surface radius of 32.65 mm and a rear surface radius of 6.38 mm. The tenth lens has a front surface radius of -16.04 mm and a rear surface radius of 2.8 mm. The eleventh lens has a front surface radius of 20.20 mm and a rear surface radius of 5.18 mm. The front surface radius of the twelfth lens is -29.00 mm; the rear surface radius is 2.8 mm.
4. The underwater white light detection lens according to claim 3, characterized in that, The lens achieves continuous zoom from 3mm to 6mm.
5. The underwater white light detection lens according to claim 4, characterized in that, When the lens is zoomed to 3mm, the relative distance between the second and third lenses is 7.94mm, the relative distance between the fourth and fifth lenses is 53.33mm, the relative distance between the aperture stop and the seventh lens is 0.1mm, the relative distance between the eighth and ninth lenses is 7.75mm, and the relative distance between the tenth and eleventh lenses is 0.1mm.
6. The underwater white low-light detection lens according to claim 5, characterized in that, When the lens is zoomed to 6mm, the relative distance between the second and third lenses is 8.64mm, the relative distance between the fourth and fifth lenses is 0.12mm, the relative distance between the aperture stop and the seventh lens is 0.15mm, the relative distance between the eighth and ninth lenses is 0.1mm, and the relative distance between the tenth and eleventh lenses is 6.23mm.
7. The underwater white light detection lens according to claim 6, characterized in that, The materials of each lens are as follows: The first lens is made of H-K11 glass; The second lens is made of H-K9L glass; The third lens is made of H-FK61 glass; The fourth lens is made of H-ZF7L glass; The fifth lens is made of H-KF6 glass; The sixth lens is made of H-LaK6 glass; The seventh lens is made of glass of model D-ZK21; The eighth lens is made of H-ZF52 glass; The ninth lens is made of H-ZK10 glass; The tenth lens is made of H-ZF52 glass; The eleventh lens is made of H-ZK10 glass; The twelfth lens is made of glass of model H-ZF52.
8. The underwater white light detection lens according to claim 1, characterized in that, The lens operates in the wavelength range of 400nm to 1000nm.
9. The mechanical packaging structure of the underwater white low-light detection lens according to any one of claims 1-8, characterized in that, The lens is encapsulated within a 6063 aluminum alloy lens barrel housing. The inside of the lens barrel is coated with an anti-reflective material. 6063 aluminum alloy spacers are used to fix the lens elements inside the lens barrel. The eleventh and twelfth lenses are fixed to the lens barrel, while the other lenses are movably connected to the lens barrel and can move along the inside of the lens barrel. During movement, the following relative fixation is maintained: the first and second lenses are relatively fixed; the third and fourth lenses are relatively fixed; the fifth and sixth lenses are relatively fixed; the seventh and eighth lenses are relatively fixed; and the ninth and tenth lenses are relatively fixed.
10. The imaging instrument of the underwater white light detection lens according to any one of claims 1-8, characterized in that, The camera was equipped with the lens.