Wide-temperature athermalization wide-angle optical lens with electromagnetic shielding effectiveness

Abstract

The invention relates to a wide-temperature athermalization wide-angle optical lens with electromagnetic shielding effectiveness, which relates to the field of optical lenses and comprises a first negative lens, a second negative lens, a third positive lens, a fourth positive lens, a fifth negative lens, a sixth negative lens, a seventh positive lens, an eighth negative lens and an image surface which are sequentially distributed along a light propagation path and are subjected to athermalization treatment, the wide-temperature athermalization lens has the advantages of electromagnetic shielding effectiveness, low distortion, large field angle and wide-temperature athermalization, and has the advantage of good optical imaging quality.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, and in particular to a wide-temperature thermally aberration wide-angle optical lens with electromagnetic shielding effectiveness. Background Technology

[0002] In many specialized fields such as aerospace, extremely high demands are placed on the wide-angle imaging capabilities of optical imaging equipment to achieve efficient capture of vast scenes. However, traditional optical lenses, limited by their field of view, struggle to meet these requirements. Furthermore, their materials are prone to deformation due to thermal expansion and contraction when operating over a wide temperature range, resulting in a significant decrease in image quality. In addition, in complex electromagnetic environments, traditional imaging units are susceptible to external electromagnetic interference, affecting image clarity and reliability, thus limiting their application in specialized scenarios.

[0003] Therefore, to address the above shortcomings, there is a need to provide a wide-temperature thermally differential wide-angle optical lens with electromagnetic shielding effectiveness. Summary of the Invention

[0004] (a) Technical problems to be solved The technical problems to be solved by this invention are the requirements for a large field of view, electromagnetic interference, and the impact of temperature changes on imaging.

[0005] (II) Technical Solution To solve the above-mentioned technical problems, the present invention provides a wide-temperature thermally aberration-reducing wide-angle optical lens with electromagnetic shielding effectiveness, comprising a first negative lens, a second negative lens, a third positive lens, a fourth positive lens, a fifth negative lens, a sixth negative lens, a seventh positive lens, an eighth negative lens, and an image plane, which are distributed sequentially along the light propagation path and are all without thermal treatment. The fifth negative lens and the sixth negative lens are cemented doublet lens groups to reduce optical chromatic aberration.

[0006] As a further explanation of the present invention, preferably, the first negative lens material is H-ZLAF52A; the second negative lens material is H-ZLAF52A; the third positive lens material is H-ZLAF68N; the fourth positive lens material is H-ZLAF68N; the fifth negative lens material is H-ZK11; the sixth negative lens material is H-ZF52; the seventh positive lens material is H-ZLAF68N; and the eighth negative lens material is H-ZLAF52A.

[0007] As a further explanation of the present invention, preferably, the front and rear surface curvatures of the first negative lens are 28.12 and 11.13, respectively; the front and rear surface curvatures of the second negative lens are -20.87 and 43.43, respectively; the front and rear surface curvatures of the third positive lens are -40.25 and -21.98, respectively; the front and rear surface curvatures of the fourth positive lens are 17.064 and 68.913, respectively; the front and rear surface curvatures of the fifth negative lens are 31.527 and -7.457, respectively; the front and rear surface curvatures of the sixth negative lens are -7.457 and -78.2, respectively; the front and rear surface curvatures of the seventh positive lens are 35.204 and -20.013, respectively; and the front and rear surface curvatures of the eighth negative lens are -14.63 and -54.562, respectively.

[0008] As a further explanation of the present invention, preferably, the first negative lens is coated with an ITO film at the light incident end.

[0009] As a further explanation of the present invention, preferably, a conductive metal ring is fitted around the periphery of the first negative lens.

[0010] As a further explanation of the present invention, preferably, a protective glass is fixedly connected to the image plane at the light incident end.

[0011] As a further explanation of the present invention, preferably, an aperture stop is provided between the fourth positive lens and the fifth negative lens.

[0012] (III) Beneficial Effects The above-described technical solution of the present invention has the following advantages: This invention, through innovative optical design, significantly expands the field of view, enabling the capture of a wider field of view in a single shot, significantly reducing the number of shots and stitching requirements, thereby greatly improving work efficiency. Simultaneously, the lens employs a special electromagnetic shielding structure to effectively resist external electromagnetic interference, ensuring stable operation of the observation system in complex electromagnetic environments and guaranteeing image quality. Furthermore, the lens features wide-temperature pyrolysis, maintaining stable imaging performance over a wide temperature range without the need for frequent focus adjustments or thermal compensation, making it adaptable to various extreme environments. This optical lens, integrating a wide field of view, electromagnetic shielding, and wide-temperature pyrolysis, can meet the optical imaging needs of various complex environments, and is particularly suitable for fields with extremely high imaging performance requirements, such as aerospace and scientific research, providing users with an efficient and reliable optical solution. Attached Figure Description

[0013] Figure 1 This is a structural diagram of the lens assembly of the present invention; Figure 2 This is a schematic diagram of the first negative lens coating and collar of the present invention; Figure 3 This is a diagram showing the F-theta distortion results of the lens in this invention; Figure 4 This is the lens transfer function curve under normal temperature conditions according to the present invention; Figure 5 This is the lens transfer function curve under -40℃ conditions according to the present invention; Figure 6 This is the lens transfer function curve under +60℃ conditions according to the present invention.

[0014] In the diagram: 1. First negative lens; 11. Conductive metal ring; 2. Second negative lens; 3. Third positive lens; 4. Fourth positive lens; 5. Fifth negative lens; 6. Sixth negative lens; 7. Seventh positive lens; 8. Eighth negative lens; 9. Image plane; 91. Protective glass; 92. Aperture stop. Detailed Implementation

[0015] 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. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] A wide-temperature pyrometric wide-angle optical lens with electromagnetic shielding effectiveness, such as... Figure 1 As shown, the lens includes a first negative lens 1, a second negative lens 2, a third positive lens 3, a fourth positive lens 4, a fifth negative lens 5, a sixth negative lens 6, a seventh positive lens 7, an eighth negative lens 8, and an image plane 9, all arranged sequentially along the light propagation path and without thermal treatment. All of these lenses have a standard spherical structure. The fifth negative lens 5 and the sixth negative lens 6 are cemented doublet lens groups to reduce optical chromatic aberration. Combination Figure 1 , Figure 2 The first negative lens 1, located at the light incident end, is coated with an ITO film. A conductive metal ring 11 surrounds the first negative lens 1. When the conductive metal ring 11 contacts the lens housing, it creates an electrical continuity effect, thereby achieving electromagnetic shielding. This ensures that the anti-reflective coating on the ITO surface maintains a transmittance of over 90%. The materials used for the first negative lens 1 are H-ZLAF52A; the second negative lens 2 is H-ZLAF52A; the third positive lens 3 is H-ZLAF68N; the fourth positive lens 4 is H-ZLAF68N; the fifth negative lens 5 is H-ZK11; the sixth negative lens 6 is H-ZF52; the seventh positive lens 7 is H-ZLAF68N; and the eighth negative lens 8 is H-ZLAF52A. Through continuous optimization of the optical system, only four lens materials with high refractive indices were ultimately used, reducing the complexity and cost of manufacturing.

[0017] like Figure 1 As shown, the front and rear surface curvatures of the first negative lens 1 are 28.12 and 11.13 respectively, and the center thickness is 2.6 mm; the front and rear surface curvatures of the second negative lens 2 are -20.87 and 43.43 respectively, and the center thickness is 1.8 mm; the front and rear surface curvatures of the third positive lens 3 are -40.25 and -21.98 respectively, and the center thickness is 5.6 mm; the front and rear surface curvatures of the fourth positive lens 4 are 17.064 and 68.913 respectively, and the center thickness is 4.5 mm. The fifth negative lens 5 has front and rear surface curvatures of 31.527 and -7.457, respectively, and a center thickness of 4.2 mm; the sixth negative lens 6 has front and rear surface curvatures of -7.457 and -78.2, respectively, and a center thickness of 1.5 mm; the seventh positive lens 7 has front and rear surface curvatures of 35.204 and -20.013, respectively, and a center thickness of 4.6 mm; the eighth negative lens 8 has front and rear surface curvatures of -14.63 and -54.562, respectively, and a center thickness of 1.8 mm. An aperture stop 92 is provided between the fourth positive lens 4 and the fifth negative lens 5. A protective glass 91 is fixed to the image plane 9 at the light incident end.

[0018] like Figure 3 As shown, under the conditions of F number 2.5, aperture 4.5mm, and system focal length 11.3mm, the lens operates in the spectral range of 486-656nm, with a full field of view of 63.6°×63.6° and full field of view F-theta distortion of less than 0.5%.

[0019] like Figure 4 As shown, the lens has a MTF (measuring the lens's ability to transmit "contrast", with a value range of 0-1, and the closer to 1, the better) greater than 0.55 at 77lp / mm (77 pairs of light and dark lines per millimeter) under normal temperature conditions, indicating that the lens has good image quality.

[0020] like Figure 5 As shown, the lens has an MTF greater than 0.55 at 77 lp / mm under normal temperature conditions, indicating that the lens has environmental adaptability at low temperatures.

[0021] like Figure 6 As shown, the lens has an MTF greater than 0.55 at 77 lp / mm under normal temperature conditions, indicating that the lens has environmental adaptability under high temperature conditions.

[0022] In summary, this invention effectively reduces optical system aberrations by employing an optimized reverse telephoto structure and high-refractive-index materials. This results in a field of view of 63.6° × 63.6° with an F-number of 2.5, an aperture of 4.5mm, and a focal length of 11.3mm. The full-field F-theta distortion is less than 0.5%, and the total system length is 65mm, allowing for the matching of 6.5μm detector pixels. Furthermore, it achieves high imaging quality over a wide temperature range of -40℃ to +60℃, avoiding the influence of ambient temperature on lens imaging quality.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wide-temperature pyroelectric wide-angle optical lens with electromagnetic shielding effectiveness, characterized in that: The system includes a first negative lens (1), a second negative lens (2), a third positive lens (3), a fourth positive lens (4), a fifth negative lens (5), a sixth negative lens (6), a seventh positive lens (7), an eighth negative lens (8), and an image plane (9), all of which are distributed sequentially along the path of light propagation and are not subjected to thermal treatment. The fifth negative lens (5) and the sixth negative lens (6) are cemented doublet lens groups to reduce optical chromatic aberration.

2. The wide-temperature thermal aberration wide-angle optical lens with electromagnetic shielding effectiveness according to claim 1, characterized in that: The first negative lens (1) is made of H-ZLAF52A; the second negative lens (2) is made of H-ZLAF52A; the third positive lens (3) is made of H-ZLAF68N; the fourth positive lens (4) is made of H-ZLAF68N; the fifth negative lens (5) is made of H-ZK11; the sixth negative lens (6) is made of H-ZF52; the seventh positive lens (7) is made of H-ZLAF68N; and the eighth negative lens (8) is made of H-ZLAF52A.

3. A wide-temperature thermally aberration wide-angle optical lens with electromagnetic shielding effectiveness according to claim 2, characterized in that: The front and back curvatures of the first negative lens (1) are 28.12 and 11.13 respectively; the front and back curvatures of the second negative lens (2) are -20.87 and 43.43 respectively; the front and back curvatures of the third positive lens (3) are -40.25 and -21.98 respectively; the front and back curvatures of the fourth positive lens (4) are 17.064 and 68.913 respectively; the front and back curvatures of the fifth negative lens (5) are 31.527 and -7.457 respectively; the front and back curvatures of the sixth negative lens (6) are -7.457 and -78.2 respectively; the front and back curvatures of the seventh positive lens (7) are 35.204 and -20.013 respectively; and the front and back curvatures of the eighth negative lens (8) are -14.63 and -54.562 respectively.

4. A wide-temperature thermally aberration wide-angle optical lens with electromagnetic shielding effectiveness according to claim 3, characterized in that: The first negative lens (1) is located at the light incident end and is coated with an ITO film.

5. A wide-temperature thermally abbreviated wide-angle optical lens with electromagnetic shielding effectiveness according to claim 4, characterized in that: The first negative lens (1) is surrounded by a conductive metal ring (11).

6. A wide-temperature thermally aberration wide-angle optical lens with electromagnetic shielding effectiveness according to claim 5, characterized in that: The image plane (9) is located at the light incident end and is fixed with a protective glass (91).

7. A wide-temperature thermally aberration wide-angle optical lens with electromagnetic shielding effectiveness according to claim 5, characterized in that: An aperture stop (92) is provided between the fourth positive lens (4) and the fifth negative lens (5).

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