A type of ultra-large light-transmitting low-light night vision lens

Abstract

This invention provides an ultra-large light-transmitting low-light night vision lens, composed of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object side to the image side. The lens employs a nine-element lens architecture, enabling an ultra-large light-transmitting design, achieving an optical design with an F-number less than 0.95. Through reasonable optical power allocation and the use of aspherical surfaces, advanced aberrations are reduced, improving imaging resolution. A glass-plastic hybrid structure is used to meet the requirements of lightweight and miniaturization. High resolution is achieved across the entire target surface, with relatively consistent image quality from the center to the edge. The lens can also be used with detectors with a 1-inch large target surface. Optical distortion is controlled through a distortion-free design, ensuring that optical distortion is no greater than 1.1%. An optically thermal design ensures normal imaging of the system in temperature environments ranging from -40℃ to +80℃.

Description

Technical Field

[0001] This invention relates to the field of night vision lens technology manufacturing, specifically to an ultra-large light-transmitting low-light night vision lens. Background Technology

[0002] Low-light night vision technology is a critical military and law enforcement tool, and it also has widespread applications in civilian sectors, such as wilderness exploration and nighttime observation. Low-light night vision lenses are highly practical devices that help users obtain clear visual information under extremely low light conditions, improving the efficiency of nighttime operations and surveillance. However, most existing low-light night vision lenses suffer from one or more of the following drawbacks:

[0003] Firstly, conventional night vision lenses are limited by their light-gathering capacity, making it difficult to provide clear and stable images under extremely low light conditions.

[0004] Secondly, low-light night vision lenses typically operate in a wide spectral band. The wider the spectral band, the greater the chromatic aberration of high-precision quantities, resulting in low overall imaging resolution.

[0005] Thirdly, conventional night vision lenses are usually made of glass lenses, especially for lenses with shorter focal lengths, which are also quite bulky and inconvenient to carry and use.

[0006] Fourth, conventional low-light night vision lenses are not good at controlling optical distortion, and the image frame is prone to obvious distortion, requiring additional algorithms for correction.

[0007] Fifth, conventional low-light night vision lenses are prone to image blurring when the ambient temperature changes. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of this invention is to propose an ultra-large light-transmitting low-light night vision lens, which adopts a nine-element lens structure. By rationally allocating the diopter of each lens, optimizing the surface shape, thickness and distance between each lens, the lens can have good image quality, thereby solving the problems mentioned in the background section above.

[0009] This invention is achieved through the following technical solution:

[0010] A high-throughput low-light night vision lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object side to the image side, wherein:

[0011] The first lens has negative refractive power, the object side of the first lens is a plane, and the image side of the first lens is concave.

[0012] The second lens has positive refractive power, the object side of the second lens is convex, and the image side of the second lens is concave.

[0013] The third lens has negative refractive power, the object side of the third lens is convex, and the image side of the third lens is concave.

[0014] The fourth lens has positive refractive power, and the object side and image side of the fourth lens are both convex.

[0015] The fifth lens has positive refractive power, and the object side of the fifth lens is convex, as is the image side of the fifth lens.

[0016] The sixth lens has negative refractive power, and the object side of the sixth lens is concave, as is the image side of the sixth lens.

[0017] The seventh lens has positive refractive power, the object side of the seventh lens is convex, and the image side of the seventh lens is concave.

[0018] The eighth lens has positive refractive power, the object side of the eighth lens is convex, and the image side of the eighth lens is concave.

[0019] The ninth lens has positive refractive power, the object side of the ninth lens is convex, and the image side of the ninth lens is concave.

[0020] The lens satisfies the following relationship: 130 < f7 < 170, 680 < f8 < 1640, 180 < f9 < 215, where f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens.

[0021] Furthermore, the optical system has an operating F-number of less than 0.95, optical distortion of less than 1.1%, and relative illumination of greater than 40%.

[0022] Furthermore, the third lens and the fourth lens constitute a first cemented lens group, and the fifth lens and the sixth lens constitute a second cemented lens group.

[0023] Furthermore, the lens satisfies the following relationship: |Vd5-Vd6|>32, where Vd5 is the Abbe number of the fifth lens and Vd6 is the Abbe number of the sixth lens.

[0024] Furthermore, the seventh, eighth, and ninth lenses are all aspherical lenses.

[0025] Furthermore, the operating wavelength of the lens is 400-1000nm.

[0026] Furthermore, the total length of the lens is less than 36.3mm.

[0027] Furthermore, the lens satisfies the following relationship: f1 < 0, where f1 is the focal length of the first lens.

[0028] Furthermore, the lens satisfies the following relationship: 0.7 < |y / f| < 0.8, where y is the image height of the lens and f is the focal length of the lens.

[0029] The beneficial effects of this invention are as follows: A high-throughput low-light night vision lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, an eighth lens, and a ninth lens arranged sequentially along the optical axis from the object side to the image side. It employs a nine-element lens architecture, enabling the lens to achieve a high-throughput design, i.e., an optical design with an F-number less than 0.95. Through reasonable optical power allocation and the use of aspherical surfaces, advanced aberrations are reduced, and imaging resolution is improved. A glass-plastic hybrid structure is adopted to meet the requirements of lightweight and miniaturization. High resolution is achieved across the entire target surface, with relatively consistent imaging quality from the center to the edge. Furthermore, the lens can be used with detectors with a 1-inch large target surface. Optical distortion is controlled through a distortion-free design, ensuring that optical distortion is no greater than 1.1%. An optically thermal-free design ensures normal imaging of the system in a temperature environment of -40℃ to +80℃. Attached Figure Description

[0030] Figure 1 This is a structural diagram of the optical system of the lens in Example 1.

[0031] Figure 2 This is the MTF diagram of the lens in Example 1.

[0032] Figure 3 This is a chromatic aberration and focus shift diagram of the lens in Example 1.

[0033] Figure 4 The image shows the optical distortion and field curvature of the lens in Example 1.

[0034] Figure 5 This is a structural diagram of the optical system of the lens in Example 2.

[0035] Figure 6 This is the MTF diagram of the lens in Example 2.

[0036] Figure 7 This is a chromatic aberration and focus shift diagram of the lens in Example 2.

[0037] Figure 8 This is a diagram showing the optical distortion and field curvature of the lens in Example 2.

[0038] Figure 9 This is a structural diagram of the optical system of the lens in Example 3.

[0039] Figure 10This is the MTF diagram of the lens in Example 3.

[0040] Figure 11 This is a chromatic aberration and focus shift diagram of the lens in Example 3.

[0041] Figure 12 The image shows the optical distortion and field curvature of the lens in Example 3.

[0042] The above figures include the following reference numerals:

[0043] 01. First lens; 02. Second lens; 03. Third lens; 04. Fourth lens; 05. Fifth lens; 06. Sixth lens; 07. Seventh lens; 08. Eighth lens; 09. Ninth lens; 10. Aperture stop; 11. Protective plate. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of aiding understanding the present invention, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] Reference Figures 1 to 12 As shown, a high-throughput low-light night vision lens (hereinafter referred to as the lens) is composed of a first lens 01, a second lens 02, a third lens 03, a fourth lens 04, a fifth lens 05, a sixth lens 06, a seventh lens 07, an eighth lens 08, and a ninth lens 09 arranged sequentially along the optical axis from the object side to the image side. An aperture stop 10 is provided between the fourth lens 04 and the fifth lens 05, and a protective sheet 11 is provided after the ninth lens 09. Wherein:

[0046] The first lens 01 has negative refractive power, the object side of the first lens 01 is flat, and the image side of the first lens 01 is concave.

[0047] The second lens 02 has positive refractive power, the object side of the second lens 02 is convex, and the image side of the second lens 02 is concave.

[0048] The third lens 03 has negative refractive power, the object side of the third lens 03 is convex, and the image side of the third lens 03 is concave.

[0049] The fourth lens 04 has positive refractive power, and the object side surface of the fourth lens 04 is convex, and the image side surface of the fourth lens 04 is convex.

[0050] The fifth lens 05 has positive refractive power, the object side of the fifth lens 05 is convex, and the image side of the fifth lens 05 is convex.

[0051] The sixth lens 06 has negative refractive power, the object side of the sixth lens 06 is concave, and the image side of the sixth lens 06 is concave.

[0052] The seventh lens 07 has positive refractive power, the object side of the seventh lens 07 is convex, and the image side of the seventh lens 07 is concave.

[0053] The eighth lens 08 has positive refractive power, the object side of the eighth lens 08 is convex, and the image side of the eighth lens 08 is concave.

[0054] The ninth lens 09 has positive refractive power, the object side of the ninth lens 09 is convex, and the image side of the ninth lens 09 is concave.

[0055] This invention achieves a large light transmission design by employing a nine-element lens architecture, that is, an optical design with an F-number of less than 0.95.

[0056] This invention reduces advanced aberrations and improves imaging resolution by rationally allocating optical power and using aspherical surfaces.

[0057] This invention adopts a glass-plastic hybrid structure to meet the requirements of lightweight and miniaturization; it achieves high resolution across the entire target surface, with relatively consistent imaging quality from the center to the edge; and the lens can also be used with a detector with a 1-inch large target surface, resulting in good imaging quality and relatively uniform imaging quality from the center to the edge.

[0058] This invention controls optical distortion and implements a distortion-free design to ensure that the optical distortion is no greater than 1.1%.

[0059] This invention employs an optically calorimetric design for the lens, ensuring normal imaging of the system in a temperature environment ranging from -40℃ to +80℃.

[0060] The lens of this invention has external dimensions of φ49.3mm*45.1mm, with the largest lens outer diameter less than 32mm, the total lens length less than 36.3mm, and the total lens weight less than 31g, meeting the requirements for lightweight use.

[0061] Furthermore, the optical system of the lens of this invention has an operating F-number of less than 0.95, optical distortion of less than 1.1%, and relative illumination of greater than 40%. This enables the lens to provide clear and stable images under extremely low light conditions.

[0062] Furthermore, the third lens 03 and the fourth lens 04 constitute a first cemented lens group, and the fifth lens 05 and the sixth lens 06 constitute a second cemented lens group. The beneficial effects of this embodiment are: firstly, the cemented lens group can reduce fitting tolerances, thereby improving lens resolution and outputting higher pixel counts; secondly, the cemented lens group helps reduce the overall length of the system, making the structure simpler.

[0063] Furthermore, the lens satisfies the following relationship: |Vd5-Vd6|>32, where Vd5 is the Abbe number of the fifth lens 05 and Vd6 is the Abbe number of the sixth lens 06. By placing a second cemented lens group behind the aperture stop 10, this lens combination greatly helps correct chromatic aberration and significantly reduces chromatic aberration and focus shift.

[0064] Furthermore, the seventh lens 07, the eighth lens 08, and the ninth lens 09 are all aspherical lenses. This structural composition not only helps correct off-axis aberrations and improve the resolution of the edge field of view, but also helps reduce the rear aperture of the lens.

[0065] Furthermore, the lens of this invention operates in the 400-1000nm wavelength range. Multiple ultra-low dispersion glasses are used to correct the secondary spectrum, significantly improving image quality.

[0066] Furthermore, the lens satisfies the following relationship: f1 < 0, where f1 is the focal length of the first lens 01. This first lens 01 employs negative optical power, which helps to reduce the front aperture of the lens.

[0067] Furthermore, the lens satisfies the following relationships: 130 < f7 < 170, 680 < f8 < 1640, 180 < f9 < 215, where f7 is the focal length of the seventh lens 07, f8 is the focal length of the eighth lens 08, and f9 is the focal length of the ninth lens 09. The beneficial effects of this embodiment are: satisfying the above formula range is beneficial for correcting aberrations, improving image quality, and facilitating calorimetric design.

[0068] Furthermore, the lens satisfies the following relationship: 0.7 < |y / f| < 0.8, where y is the image height of the lens and f is the focal length of the lens. The beneficial effects of this embodiment are: satisfying the above range is more conducive to achieving a large target surface, optimizing distortion, and meeting the requirement of distortion-free operation.

[0069] The present invention will now be described in more detail with reference to Tables 1 to 7. It should be noted that the following tables are merely specific embodiments of the present invention and not limiting examples.

[0070] Table 1 shows the specific arrangement of parameters such as the radius of curvature and thickness interval of each lens in Embodiment 1 of the present invention.

[0071]

[0072] Table 2 shows the specific arrangement of parameters such as the curvature radius and thickness interval of each lens in Embodiment 2 of the present invention.

[0073]

[0074] Table 3 shows the specific arrangement of parameters such as the radius of curvature and thickness interval of each lens in Embodiment 3 of the present invention.

[0075]

[0076] Table 4 shows the focal length values ​​of each lens in Embodiment 1 of the present invention.

[0077]

[0078] Table 5 shows the focal length values ​​of each lens in Embodiment 2 of the present invention.

[0079]

[0080] Table 6 shows the focal length values ​​of each lens in Embodiment 3 of the present invention.

[0081]

[0082] Table 7 shows the specific arrangement of embodiments 1 to 3 of the present invention. In the table, f is the focal length, BFL is the optical back focal length, y is the image height of the lens, and TTL is the total optical length of the lens.

[0083]

[0084] The following are explanations of each attached figure:

[0085] Figure 2 The image shows the MTF (Mean Transformer Format) of the lens in Example 1. As can be seen from the image, the contrast ratio of the lens across the entire field of view is greater than 0.28 at 50 lp / mm, indicating uniform image quality and high resolution.

[0086] Figure 3 This is a chromatic aberration and focus shift diagram of the lens in Example 1. As can be seen from the diagram, the lens chromatic aberration and focus shift are less than 41µm, resulting in good night vision performance.

[0087] Figure 4 The image shows the optical distortion and field curvature of the lens in Example 1. As can be seen from the image, the lens optical distortion is less than 2%, field curvature is well controlled, and image fidelity is high.

[0088] Figure 6 The image shows the MTF (Mean Transformer Format) of the lens in Example 2. As can be seen from the image, the contrast ratio of the lens across the entire field of view is greater than 0.25 at 50 lp / mm, indicating uniform image quality and high resolution.

[0089] Figure 7 This is a chromatic aberration and focus shift diagram of the lens in Example 2. As can be seen from the diagram, the lens chromatic aberration and focus shift are less than 39.1 μm, resulting in good night vision performance.

[0090] Figure 8 The image shows the optical distortion and field curvature of the lens in Example 2. As can be seen from the image, the lens optical distortion is less than 2%, field curvature control is good, and image fidelity is high.

[0091] Figure 10 The image shows the MTF (Mean Transformer Format) of the lens in Example 3. As can be seen from the image, the contrast ratio of the lens across the entire field of view is greater than 0.3 at 50 lp / mm, indicating uniform image quality and high resolution.

[0092] Figure 11 This is a chromatic aberration and focus shift diagram of the lens in Example 3. As can be seen from the diagram, the lens chromatic aberration and focus shift are less than 39.5 μm, resulting in good night vision performance.

[0093] Figure 12 The image shows the optical distortion and field curvature of the lens in Example 3. As can be seen from the image, the lens optical distortion is less than 2%, field curvature is well controlled, and image fidelity is high.

[0094] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0095] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0096] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A high-throughput low-light night vision lens, characterized in that: It consists of a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, and a ninth lens, arranged sequentially along the optical axis from the object side to the image side, wherein: The first lens has negative refractive power, the object side of the first lens is a plane, and the image side of the first lens is concave. The second lens has positive refractive power, the object side of the second lens is convex, and the image side of the second lens is concave. The third lens has negative refractive power, the object side of the third lens is convex, and the image side of the third lens is concave. The fourth lens has positive refractive power, and the object side and image side of the fourth lens are both convex. The fifth lens has positive refractive power, and the object side of the fifth lens is convex, as is the image side of the fifth lens. The sixth lens has negative refractive power, and the object side of the sixth lens is concave, as is the image side of the sixth lens. The seventh lens has positive refractive power, the object side of the seventh lens is convex, and the image side of the seventh lens is concave. The eighth lens has positive refractive power, the object side of the eighth lens is convex, and the image side of the eighth lens is concave. The ninth lens has positive refractive power, the object side of the ninth lens is convex, and the image side of the ninth lens is concave. The lens satisfies the following relationship: 130 < f7 < 170, 680 < f8 < 1640, 180 < f9 < 215, where f7 is the focal length of the seventh lens, f8 is the focal length of the eighth lens, and f9 is the focal length of the ninth lens.

2. The ultra-large light-transmitting low-light night vision lens according to claim 1, characterized in that: The optical system has an operating F-number of less than 0.95, optical distortion of less than 1.1%, and relative illumination of greater than 40%.

3. The ultra-large light-transmitting low-light night vision lens according to claim 1, characterized in that: The third lens and the fourth lens constitute the first cemented lens group, and the fifth lens and the sixth lens constitute the second cemented lens group.

4. The ultra-large light-transmitting low-light night vision lens according to claim 3, characterized in that: The lens satisfies the following relationship: |Vd5-Vd6|>32, where Vd5 is the Abbe number of the fifth lens and Vd6 is the Abbe number of the sixth lens.

5. The ultra-large light-transmitting low-light night vision lens according to claim 1, characterized in that: The seventh, eighth, and ninth lenses are all aspherical lenses.

6. The ultra-large light-transmitting low-light night vision lens according to claim 1, characterized in that: The lens operates in the 400-1000nm wavelength range.

7. The ultra-large light-transmitting low-light night vision lens according to claim 1, characterized in that: The total length of the lens is less than 36.3mm.

8. The ultra-large light-transmitting low-light night vision lens according to claim 1, characterized in that: The lens satisfies the following relationship: f1 < 0, where f1 is the focal length of the first lens.

9. A high-transmission low-light night vision lens according to claim 1, characterized in that: The lens satisfies the following relationship: 0.7 < |y / f| < 0.8, where y is the image height of the lens and f is the focal length of the lens.

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