An ultra-wide-angle micro-light lens

Abstract

The present application belongs to the technical field of spaceborne electronic-optical information collection, and particularly relates to a super-wide-angle micro-light lens, comprising a front group, an aperture, a rear group, a parallel flat and an image plane arranged in sequence along a light incident direction, wherein the front group comprises a first single lens, a second single lens, a first cemented group, a fourth single lens and a fifth single lens arranged in sequence along the light incident direction, the rear group comprises a second cemented group, a sixth single lens, a third cemented group and a filter arranged in sequence along the light incident direction, the front surface of the first single lens is a high-order axisymmetric aspheric surface, the front surface of the fourth single lens is a high-order axisymmetric aspheric surface, and the rear surface of the sixth single lens is a high-order axisymmetric aspheric surface, and the present application has the advantages of super-wide-angle small distortion, wide-spectrum design with large relative aperture and optical passive light design.

Description

Technical Field

[0001] This invention belongs to the field of aerospace airborne electro-optical information acquisition technology, specifically relating to an ultra-wide-angle low-light lens. Background Technology

[0002] Information acquisition is crucial in aerospace electronics, especially in detector imaging applications. Optical information is collected through corresponding lenses and then used by auxiliary equipment to form images, providing sufficient information support for the use of aerospace equipment. In the use of optical lenses, the field of view determines the size of the scene that the lens can capture. A larger field of view means acquiring more information over a wider angular space. However, in practical use, ultra-wide-angle lenses can cause significant image distortion. Image distortion results in a large difference between the image and the real scene, leading to poor realism and limiting the use of ultra-wide-angle lenses. Furthermore, their commonly used visible light range is relatively narrow, only usable in the white light spectrum from 480nm to 700nm. It is necessary to broaden the spectral range to the low-light band. Low-light lenses enable imaging of targets invisible to the human eye onto the detector target surface even under night sky light or low illumination conditions, greatly improving the visual performance of the human eye in low light. Therefore, solving the image distortion problem of ultra-wide-angle low-light lenses is very important in the process of optical information imaging.

[0003] Patent application number CN201920949708.X discloses a large-aperture, low-distortion optical lens, which effectively reduces the interference of distortion by changing the shape and structure of the lens. However, the lens angle range is only 80°, which is significantly different from the applicable range of an ultra-wide-angle lens, and its degree of distortion interference is relatively weak. Patent application number CN201821436717.0 discloses a lightweight, miniaturized, large-area low-light lens, but its lens angle range is only 50°, and it has virtually no effect on anti-distortion interference.

[0004] Patent application CN201920949708.X discloses a wide-field-of-view multi-band stereo vision-assisted driving device. Although it is applied to the wide-angle field, its structure is very complex and heavy, and its distortion rate even reaches 23%. This is significantly different from the requirements for using existing ultra-wide-angle lenses.

[0005] Therefore, there is an urgent need for an ultra-wide-angle low-light lens that can reduce the distortion of existing ultra-wide-angle lenses by modifying the internal structure and lens materials, and provide clearer images for use in aerospace airborne electro-optical systems. Summary of the Invention

[0006] In view of this, the present invention proposes an ultra-wide-angle low-light lens, which solves the technical problems of large field distortion, lack of large relative aperture and wide spectrum design and lack of optical passive calorimetry design in existing ultra-wide-angle lenses by modifying the lens material and structure.

[0007] To achieve the above-mentioned technical objectives, the specific technical solution adopted by the present invention is as follows:

[0008] An ultra-wide-angle low-light lens includes a front group, an aperture stop, a rear group, a parallel plate, and an image plane arranged sequentially along the light incident direction. The front group includes a first single lens, a second single lens, a first cemented lens group, a fourth single lens, and a fifth single lens arranged sequentially along the light incident direction. The rear group includes a second cemented lens group, a sixth single lens, a third cemented lens group, and a filter arranged sequentially along the light incident direction. The front surface of the first single lens is a high-order axisymmetric aspherical surface. The first cemented lens group consists of a first meniscus negative lens and a biconcave negative lens cemented together. The front surface of the fourth single lens is a high-order axisymmetric aspherical surface. The second cemented lens group consists of a meniscus positive lens and a plano-convex negative lens cemented together. The rear surface of the sixth single lens is a high-order axisymmetric aspherical surface. The third cemented lens group consists of a second meniscus negative lens and a biconvex positive lens cemented together.

[0009] Furthermore, the first single lens has an optical power of -0.046 and is made of HLAF50B optical glass material; the second single lens has an optical power of -0.055 and is made of HZLAF4LA optical glass material; the first cemented assembly has an optical power of -0.042; the meniscus negative lens inside the first cemented assembly is made of HZLAF4LA optical glass material; the biconcave negative lens inside the first cemented assembly is made of HZPK5 optical glass material; the fourth single lens has an optical power of 0.041 and is made of HZLAF4LA optical glass material; and the fifth single lens has an optical power of approximately 0.042 and is made of HLAK4LA optical glass material.

[0010] Furthermore, the distance between the first single lens and the second single lens is 6 mm; the distance between the second single lens and the first cemented group is 5.2 mm; the distance between the first cemented group and the fourth single lens is 0.9 mm; and the distance between the fourth single lens and the fifth single lens is 0.25 mm.

[0011] Furthermore, the optical power of the second cemented group is 0.014, the meniscus positive lens inside the second cemented group is made of optical glass material HZF52, the plano-convex negative lens inside the second cemented group is made of optical glass material HZPK5, the optical power of the sixth single lens is 0.048, and it is made of optical glass material HLAF50B. The optical power of the third cemented group is 0.012, the meniscus negative lens inside the third cemented group is made of optical glass material HZF13, and the lens inside the third cemented group is made of optical glass material HZPK5.

[0012] Furthermore, the distance between the second cemented group and the sixth single lens is 0.2 mm, and the distance between the sixth single lens and the third cemented group is 0.2 mm.

[0013] Furthermore, the aperture is positioned between the front and rear groups, the distance between the fifth single lens and the aperture is 8.6 mm, and the distance between the aperture and the second cemented group is 0.2 mm.

[0014] Furthermore, the distance between the filter and the third adhesive assembly is 2.23 mm, the distance between the filter and the parallel plate is 4 mm, and the distance between the parallel plate and the image plane is 0.27 mm.

[0015] Furthermore, the filter is made of HK9L optical glass material.

[0016] By adopting the above technical solution, the present invention can also bring the following beneficial effects:

[0017] 1. This invention utilizes a strong negative optical power element and a high refractive index material to bend light and cover a wider field of view. The lens incorporates three high-order aspherical planes to correct optical distortion, thereby greatly reducing the distortion of the ultra-wide-angle low-light lens and facilitating its use in the field of aerospace airborne electro-optical information acquisition technology.

[0018] 2. This invention achieves large relative aperture imaging through the cooperation of multiple components inside the lens, enabling the lens to collect more night sky radiation in low-light environments. Furthermore, the working wavelength extends into the near-infrared radiation spectrum range, and the wide-spectrum design allows the lens to produce clear images in extremely low-light environments at night.

[0019] 3. The present invention has a simple and compact structure, is easy to assemble and debug, and is convenient to replace and maintain. At the same time, by using all-glass optical elements in the lens, the passive and heatless optical design is achieved by simply combining materials and rationally allocating optical power without changing the types of materials. As a result, the optical system can maintain clear imaging in a temperature range of -55℃ to +70℃, which greatly expands the application range of the ultra-wide-angle low-light lens. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the ultra-wide-angle low-light lens in a specific embodiment of the present invention;

[0022] Figure 2This is a distortion evaluation result diagram of the ultra-wide-angle low-light lens in a specific embodiment of the present invention;

[0023] Figure 3 This is a graph showing the room temperature (20°C) MTF evaluation results of the ultra-wide-angle low-light lens in a specific embodiment of the present invention;

[0024] Figure 4 This is a graph showing the -55℃ MTF evaluation results of the ultra-wide-angle low-light lens in a specific embodiment of the present invention;

[0025] Figure 5 This is a graph showing the 70℃ MTF evaluation results of the ultra-wide-angle low-light lens in a specific embodiment of the present invention.

[0026] Among them: 1. Front group; 2. Aperture stop; 3. Rear group; 4. Parallel plate; 5. Image plane; 11. First single lens; 12. Second single lens; 13. First cemented group; 14. Fourth single lens; 15. Fifth single lens; 31. Second cemented group; 32. Sixth single lens; 33. Third cemented group; 34. Filter; 131. First meniscus negative lens; 132. Biconcave negative lens; 311. Meniscus positive lens; 312. Plano-convex negative lens; 331. Second meniscus negative lens; 332. Biconvex positive lens. Detailed Implementation

[0027] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0028] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this invention, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0030] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0031] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that these aspects can be practiced without these specific details.

[0032] like Figure 1 As shown, in one embodiment of the present invention, the interior of the ultra-wide-angle low-light lens is provided with a front group 1, an aperture stop 2, a rear group 3, a parallel plate 4, and an image plane 5 arranged sequentially along the light incident direction; the front group 1 includes a first single lens 11, a second single lens 12, a first cemented group 13, a fourth single lens 14, and a fifth single lens 15 arranged sequentially along the light incident direction; the rear group 3 includes a second cemented group 31, a sixth single lens 32, a third cemented group 33, and a filter 34 arranged sequentially along the light incident direction.

[0033] The first single lens has an optical power of approximately -0.046 and is made of HLAF50B optical glass material. Its front surface is a high-order axisymmetric aspherical surface.

[0034] The second single lens 12 has an optical power of approximately -0.055 and is made of optical glass material HZLAF4LA.

[0035] The first cemented assembly 13 is composed of a first meniscus negative lens 131 and a biconcave negative lens 132 cemented together, with an optical power of -0.042. The first meniscus negative lens 131 is made of optical glass material HZLAF4LA, and the biconcave negative lens 132 is made of optical glass material HZPK5.

[0036] The fourth single lens 14 has an optical power of 0.041 and is made of optical glass material HZLAF4LA. Its front surface is a high-order axisymmetric aspherical surface.

[0037] The fifth single lens 15 has an optical power of 0.042 and is made of optical glass material HLAK4LA.

[0038] The second cemented assembly 31 is cemented together with a meniscus positive lens 311 and a plano-convex negative lens 312, with an optical power of approximately 0.014. The meniscus positive lens 311 is made of optical glass material HZF52, and the plano-convex negative lens 312 is made of optical glass material HZPK5.

[0039] The sixth single lens 32 has an optical power of 0.048 and is made of HLAF50B optical glass material. Its rear surface is a high-order axisymmetric aspherical surface.

[0040] The third cemented assembly 33 is composed of a second meniscus negative lens 331 and a biconvex positive lens 332 cemented together, with an optical power of approximately 0.012. The second meniscus negative lens 331 is made of optical glass material HZF13, and the biconvex positive lens 332 is made of optical glass material HZPK5.

[0041] The filter 34 is made of optical glass material HK9L.

[0042] The distance between the first single lens 11 and the second single lens 12 is 6 mm; the distance between the second single lens 12 and the first cemented group 13 is 5.2 mm; the distance between the first cemented group 13 and the fourth single lens 14 is 0.9 mm; the distance between the fourth single lens 14 and the fifth single lens 15 is 0.25 mm; the distance between the fifth single lens 15 and the aperture 2 is 8.6 mm; the distance between the aperture 2 and the second cemented group 31 is 0.2 mm; the distance between the second cemented group 31 and the sixth single lens 32 is 0.2 mm; the distance between the sixth single lens 32 and the third cemented group 33 is 0.2 mm; the distance between the third cemented group 33 and the filter 34 is 2.23 mm; the distance between the filter 34 and the parallel plate 4 is 4 mm; and the distance between the parallel plate 4 and the image plane 5 is 0.27 mm.

[0043] The corresponding optical parameters are shown in the table below.

[0044] Optical System Data Sheet

[0045]

[0046]

[0047] The general form of an aspherical surface is:

[0048] Where c = 1 / R is the vertex curvature, K is the quadratic curve constant, and A, B, C, and D are higher-order aspheric coefficients. The first term is the general quadratic surface equation; the general form of an aspheric surface is based on a quadratic curve with added higher-order terms. K = 0 indicates that the quadratic surface equation in the first term is a sphere. The radius of the aspheric surface in the table is the radius of curvature at the vertex, and h is the radial coordinate perpendicular to the optical axis.

[0049] like Figures 2-5 As shown, the ultra-wide-angle low-light lens in this embodiment has a field of view of 110°, a full field of view distortion of 5%, a relative aperture F / # of 1.8, and is applicable to wavelengths between 480nm and 1000nm. It also has an optical calorimetry effect and can maintain clear imaging within a temperature range of -55℃ to 70℃. In summary, this invention has the advantages of ultra-wide-angle low distortion, large relative aperture wide spectrum design, and optical passive calorimetry design.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An ultra-wide angle micro-lens, characterized by: The system includes a front group (1), an aperture stop (2), a rear group (3), a parallel plate (4), and an image plane (5) arranged sequentially along the light incident direction. The front group (1) includes a first single lens (11), a second single lens (12), a first cemented group (13), a fourth single lens (14), and a fifth single lens (15) arranged sequentially along the light incident direction. The rear group (3) includes a second cemented group (31), a sixth single lens (32), a third cemented group (33), and a filter (34) arranged sequentially along the light incident direction. The front surface of the single lens (11) is a high-order axisymmetric aspherical surface. The first cemented group (13) is formed by cementing the first meniscus negative lens (131) and the biconcave negative lens (132). The front surface of the fourth single lens (14) is a high-order axisymmetric aspherical surface. The second cemented group (31) is formed by cementing the meniscus positive lens (311) and the plano-convex negative lens (312). The rear surface of the sixth single lens (32) is a high-order axisymmetric aspherical surface. The third cemented group (33) is formed by cementing the second meniscus negative lens (331) and the biconvex positive lens (332). The first single lens (11) has an optical power of -0.046 and is made of optical glass material HLAF50B. The second single lens (12) has an optical power of -0.055 and is made of optical glass material HZLAF4LA. The first cemented assembly (13) has an optical power of -0.

042. The meniscus negative lens inside the first cemented assembly (13) is made of optical glass material HZLAF4LA. The biconcave negative lens inside the first cemented assembly (13) is made of optical glass material HZPK5. The fourth single lens (14) has an optical power of 0.041 and is made of optical glass material HZLAF4LA. The fifth single lens (15) has an optical power of approximately 0.042 and is made of optical glass material HLAK4LA.

2. The ultra-wide-angle low-light lens according to claim 1, characterized in that: The distance between the first single lens (11) and the second single lens (12) is 6 mm; the distance between the second single lens (12) and the first cemented group (13) is 5.2 mm; the distance between the first cemented group (13) and the fourth single lens (14) is 0.9 mm; and the distance between the fourth single lens (14) and the fifth single lens (15) is 0.25 mm.

3. The ultra-wide-angle low-light lens according to claim 2, characterized in that: The optical power of the second cemented group (31) is 0.

014. The meniscus positive lens inside the second cemented group (31) is made of optical glass material HZF52. The plano-convex negative lens inside the second cemented group (31) is made of optical glass material HZPK5. The optical power of the sixth single lens (32) is 0.048 and is made of optical glass material HLAF50B. The optical power of the third cemented group (33) is 0.

012. The meniscus negative lens inside the third cemented group (33) is made of optical glass material HZF13. The lens inside the third cemented group (33) is made of optical glass material HZPK5.

4. The ultra-wide-angle low-light lens according to claim 3, characterized in that: The distance between the second cemented group (31) and the sixth single lens (32) is 0.2 mm, and the distance between the sixth single lens (32) and the third cemented group (33) is 0.2 mm.

5. The ultra-wide-angle low-light lens according to claim 4, characterized in that: The aperture (2) is positioned between the front group (1) and the rear group (3). The distance between the fifth single lens (15) and the aperture (2) is 8.6 mm, and the distance between the aperture (2) and the second cemented group (31) is 0.2 mm.

6. The ultra-wide-angle low-light lens according to claim 5, characterized in that: The distance between the filter (34) and the third adhesive assembly (33) is 2.23 mm, the distance between the filter (34) and the parallel plate (4) is 4 mm, and the distance between the parallel plate (4) and the image plane (5) is 0.27 mm.

7. The ultra-wide-angle low-light lens according to claim 6, characterized in that: The filter (34) is made of optical glass material HK9L.

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