A high-precision, large-field collimator

Abstract

The present invention provides a high-precision, large-field-of-view collimator. The optical system of the high-precision, large-field-of-view collimator comprises, in order from the human eye to the light source, a first plano-convex lens, a first biconcave lens, a first meniscus lens, a first biconvex lens, a second biconvex lens, a second meniscus lens, a third meniscus lens, a graticule, an acrylic plate, and a uniform array light source. The optical elements of the optical system all use conventional large-aperture CDGM glass, avoiding the use of a low-conversion melting process during glass processing and effectively reducing costs. The optical system has a full field of view of 63° and a maximum distortion of less than 0.11%. By matching existing optical glass materials to correct chromatic aberration in the visible light range, the accuracy of the graticule lines on the collimator is less than 2′, which can meet the requirements for high-precision, large-field-of-view products.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detection technology, and in particular to a high-precision large-field-of-view collimator. Background Art

[0002] A collimator is an optical testing instrument typically consisting of a lens assembly, a reticle, and a light source. Its primary function is to generate parallel light through a specific optical system to simulate an infinitely distant target. Optical components such as a reticle and a star point plate are placed at the focal plane of the collimator lens assembly to verify the optical performance of the optical system being tested.

[0003] Due to the current needs of astronomical observation and space exploration, space-based earth observation, national defense and security, optical systems with higher resolution have become the mainstream development direction, and thus optical systems with large apertures and large fields of view have been developed. Correspondingly, in order to meet the high-precision detection requirements of large apertures and large fields of view of the above optical systems, the demand for developing collimators with large apertures, large fields of view, and high test accuracy is also increasing. However, the field of view angles of the mainstream large-field collimators on the market are mostly between 40° and 50°, and the field of view test accuracy is between 2′ and 3′, which cannot meet the performance and precision detection requirements of the tested products at larger angles. Therefore, it is necessary to further improve the field of view angle and field of view test accuracy of collimators. Summary of the Invention

[0004] The object of the present invention is to provide a high-precision large-field-of-view collimator, which is used to improve the technical problems of the existing collimators, such as the small field-of-view angle range and low field-of-view test accuracy.

[0005] To solve the above technical problems, the present invention provides a high-precision, large-field-of-view collimator, comprising an objective lens group, a reticle, and a light source assembly arranged in sequence, wherein the objective lens group is arranged in sequence from the visual direction to the light source assembly as a first plano-convex lens, a first biconcave lens, a first meniscus lens, a first biconvex lens, a second biconvex lens, a second meniscus lens, and a third meniscus lens; the refractive index and Abbe number corresponding to each lens in the objective lens group satisfy the following conditions: 1.729≤n1, 54.685≤v1; 1.672≤n2, 32.171≤v2; 1.620≤n3, 60.339≤v3; 1.620≤n4, 60.339≤v4; 1.487≤n5, 70.440≤v5; 1.755≤n6, 27.530≤v6; 1.620≤n7, 60.339≤v7;

[0006] Among them, n1, n2, n3, n4, n5, n6, and n7 are the refractive indices of the first plano-convex lens, the first biconcave lens, the first meniscus lens, the first biconvex lens, the second biconvex lens, the second meniscus lens, and the third meniscus lens respectively; v1, v2, v3, v4, v5, v6, and v7 are the Abbe numbers of the first plano-convex lens, the first biconcave lens, the first meniscus lens, the first biconvex lens, the second biconvex lens, the second meniscus lens, and the third meniscus lens respectively.

[0007] Preferably, the first plano-convex lens, the first biconcave lens, the first meniscus lens, the first biconvex lens, the second biconvex lens, the second meniscus lens and the third meniscus lens are all made of large-aperture glass materials; and a stop is further provided at the exit pupil diameter of the objective lens group.

[0008] Preferably, the air gap between the first plano-convex lens and the first biconcave lens is 16.58-16.59 mm; the air gap between the first biconcave lens and the first meniscus lens is 17.58-17.59 mm; the air gap between the first meniscus lens and the first biconvex lens is 1.00-1.01 mm; the air gap between the first biconvex lens and the second biconvex lens is 36.26-36.27 mm; the air gap between the second biconvex lens and the second meniscus lens is 41.84-41.85 mm; and the air gap between the second meniscus lens and the third meniscus lens is 51.82-51.83 mm.

[0009] Preferably, light is emitted from the uniform array light source of the light source assembly through the objective lens group toward the visual direction. The curvature radius of the concave surface through which the light passes is a positive number, and the curvature radius of the convex surface through which the light passes is a negative number. The curvature radius corresponding to each lens in the objective lens group satisfies the following conditions:

[0010] The curvature radius of the first plano-convex lens away from the first biconcave lens is in the range of 220 to 230 mm, and the curvature radius of the first plano-convex lens close to the first biconcave lens is infinite; the curvature radius of the first biconcave lens away from the first meniscus lens is in the range of -180 to -190 mm, and the curvature radius of the first biconcave lens close to the first meniscus lens is in the range of 550 to 560 mm; the curvature radius of the first meniscus lens away from the first biconvex lens is in the range of -420 to -430 mm, and the curvature radius of the first meniscus lens close to the first biconvex lens is in the range of -170 to -180 mm; the curvature radius of the first biconvex lens away from the second biconvex lens is in the range of 290 to 300 mm, and the first biconvex lens is in the range of 100 to 250 mm. The curvature radius of the lens on the side close to the second biconvex lens ranges from -600 to -610mm; the curvature radius of the second biconvex lens on the side away from the second meniscus lens ranges from 930 to 940mm, and the curvature radius of the second biconvex lens on the side close to the second meniscus lens ranges from -310 to -320mm; the curvature radius of the second meniscus lens on the side away from the third meniscus lens ranges from -200 to -210mm, and the curvature radius of the second meniscus lens on the side close to the third meniscus lens ranges from -730 to -740mm; the curvature radius of the third meniscus lens on the side away from the reticle ranges from -140 to -150mm, and the curvature radius of the third meniscus lens on the side close to the reticle ranges from -570 to -580mm.

[0011] Preferably, the center thickness range of the first plano-convex lens is 23 to 23.5 mm, the center thickness of the first biconcave lens is 15.0 to 15.5 mm, the center thickness of the first meniscus lens is 29.0 to 29.5 mm, the center thickness of the first biconvex lens is 49.0 to 49.5 mm, the center thickness range of the second biconvex lens is 48 to 48.5 mm, the center thickness range of the second meniscus lens is 18 to 18.5 mm, and the center thickness range of the third meniscus lens is 20 to 20.5 mm; the distance between the edge of the third meniscus lens and the graticule is 15 to 16 mm.

[0012] Preferably, the focal length of the objective lens group is 260 mm, the exit pupil distance is 60-61 mm, the exit pupil diameter is 80 mm, the full field angle is 63°, the working band is 0.486-0.656 μm, the maximum distortion is 0.11%, and the total optical length is 443.13 mm.

[0013] Preferably, the high-precision large-field collimator further comprises a fixing assembly, the fixing assembly comprising a front fixing member, a middle fixing member and a rear fixing member sequentially connected from the visual direction to the light source assembly direction;

[0014] Among them, the front fixing component is used to fix the first plano-convex lens, the first biconcave lens and the first meniscus lens; the middle fixing component is used to fix the first biconvex lens and the second biconvex lens; the rear fixing component is used to fix the second meniscus lens, the third meniscus lens, the dividing plate and the light source assembly.

[0015] Preferably, the front fixing member, the middle fixing member and the rear fixing member are fixedly connected by means of a locking screw; and a mirror cover member is provided on the outer side of the front fixing member close to the visual direction.

[0016] Preferably, the light source assembly includes an acrylic plate, a uniform array light source and a power module arranged in sequence from the visual direction to the light source assembly direction, and the acrylic plate, the uniform array light source and the power module are all fixed in the rear fixing component.

[0017] The beneficial effects of the present invention are as follows: different from the prior art, the present invention provides a high-precision large-field-of-view collimator, in which the objective lens group in the high-precision large-field-of-view collimator is arranged in sequence from the visual direction to the light source component direction as a first plano-convex lens, a first biconcave lens, a first meniscus lens, a first biconvex lens, a second biconvex lens, a second meniscus lens and a third meniscus lens; wherein the first plano-convex lens bears the focal length of the system, causes a large deflection of off-axis light, and constrains the aperture of subsequent lenses of the objective lens group; the first biconcave lens generates negative field curvature, negative astigmatism and negative distortion, which are used to correct the positive distortion generated by the first plano-convex lens and compensate for astigmatism; the first meniscus lens is used to The optical objective lens group is used to provide positive field curvature, thereby correcting the astigmatism produced by the first plano-convex lens and the first biconcave lens; the first biconvex lens and the second biconvex lens provide positive distortion and compress the system light aperture; the second meniscus lens and the third meniscus lens provide negative distortion and negative field curvature, which can compensate for the residual distortion, residual field curvature and astigmatism of the first five lenses; at the same time, the above-mentioned objective lens group has good correction of chromatic aberration, astigmatism, coma, field curvature and distortion by reasonably controlling the refractive index and Abbe number of each lens, which can meet the use requirements of high-precision and large-field-of-view products, and can provide a wider test range for the optical performance test of aviation head-up displays and helmet sights. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic diagram of the optical system structure of a high-precision, large-field-of-view collimator provided in Example 1 of the present invention;

[0019] Figure 2 Schematic diagram of the optical system light path of the high-precision, large-field-of-view collimator provided in Example 1 of the present invention;

[0020] Figures 3A to 3E This is a light fan diagram of a high-precision, large-field-of-view collimator provided by Example 1 of the present invention at different object plane angles;

[0021] Figure 4 This is a spot diagram of a high-precision, large-field-of-view collimator provided in Example 1 of the present invention;

[0022] Figure 5 This is a diagram of field curvature and distortion of a high-precision, large-field-of-view collimator provided in Example 1 of the present invention;

[0023] Figures 6A to 6B This is a cross-sectional view of the overall structure of a high-precision, large-field-of-view collimator provided in Example 1 of the present invention;

[0024] In the figure: 10 - objective lens group; 11 - first plano-convex lens; 12 - first biconcave lens; 13 - first meniscus lens; 14 - first biconvex lens; 15 - second biconvex lens; 16 - second meniscus lens; 17 - third meniscus lens; 20 - reticle; 30 - light source assembly; 31 - acrylic plate; 32 - uniform array light source; 33 - power module; 40 - fixing assembly; 41 - rolling block; 42 - front fixing member; 421 - first spacer; 422 - first pressure ring; 423 - first objective Frame; 424 - second pressure ring; 425 - third pressure ring; 426 - front tube; 43 - middle fixing member; 431 - second spacer; 432 - fourth pressure ring; 433 - middle tube; 44 - rear fixing member; 441 - second objective frame; 442 - sixth pressure ring; 443 - third objective frame; 444 - fifth pressure ring; 445 - rear tube; 446 - seventh pressure ring; 447 - eighth pressure ring; 448 - rear pressure ring of the tube; 449 - reticle frame; 45 - light source cover; 50 - lens cover assembly. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] The purpose of the present invention is to provide a high-precision large-field-of-view collimator to address the defects of the prior art, so as to meet the requirements of optical system performance testing with larger aperture, field of view and higher precision.

[0027] The technical solution of the present invention will now be described with reference to specific embodiments.

[0028] Example 1:

[0029] See also Figure 1 、 Figures 6A to 6B , Figure 1 1 is a schematic diagram of the optical system structure of a high-precision, large-field-of-view collimator provided in Example 1 of the present invention; Figures 6A to 6BIt is a structural cross-sectional view of a high-precision, large-field-of-view collimator provided in Example 1 of the present invention; wherein, the high-precision, large-field-of-view collimator provided by the present invention comprises an objective lens group 10, a graticule 20 and a light source assembly 30 arranged in sequence, and the objective lens group 10 is arranged in sequence from the visual direction to the light source assembly 30 as a first plano-convex lens 11, a first biconcave lens 12, a first meniscus lens 13, a first biconvex lens 14, a second biconvex lens 15, a second meniscus lens 16 and a third meniscus lens 17.

[0030] In the embodiment of the present invention, the objective lens group 10 has the following important functions: light collimation: converging and collimating the divergent light from the light source assembly 30 so that it is emitted as parallel light to meet the basic functional requirements of the collimator; aberration correction: through the combination and arrangement of different lenses, various aberrations, including spherical aberration, coma, astigmatism, field curvature and distortion, are effectively corrected, thereby improving the clarity and quality of imaging; expanding the field of view: reasonable design and matching of lenses of different shapes and characteristics can achieve a larger field of view, so that the collimator can observe a wider area; improving resolution: through precise lens design and manufacturing, the system's resolving power is enhanced so that subtle details can be clearly presented; optimizing light intensity distribution: ensuring that the light intensity distribution of parallel light is uniform throughout the field of view to avoid uneven brightness.

[0031] Specifically, the first plano-convex lens 11 of the objective lens group 10 bears the optical focal length of the system, causing a large deflection of off-axis light, thereby constraining the aperture of subsequent lenses of the objective lens group 10; the first biconcave lens 12 produces negative field curvature, negative astigmatism and negative distortion, which are used to correct the positive distortion produced by the first plano-convex lens 11 and compensate for astigmatism; the first meniscus lens 13 is used to provide positive field curvature, thereby correcting the astigmatism produced by the first plano-convex lens 11 and the first biconcave lens 12; the first biconvex lens 14 and the second biconvex lens 15 provide positive distortion and compress the aperture of the system light; the second meniscus lens 16 and the third meniscus lens 17 provide negative distortion and negative field curvature, which can compensate for the residual distortion, residual field curvature and astigmatism of the first five lenses.

[0032] Due to the inherent physical and chemical limitations of glass, domestic glass processing manufacturers currently require large inventories of glass blanks to be melted to the required size when processing lenses with diameters exceeding 160 mm. Except for certain brands of glass blanks that have large inventories, all other brands must undergo a melting process to melt large quantities of glass blanks to the required size. Due to the low conversion efficiency of the melting process, the processing of each large-diameter glass results in a large amount of blank glass being wasted, significantly increasing processing costs. To ensure low costs, the present invention avoids the use of low-dispersion glass that deviates from the glass dispersion curve during the design phase. Conventional glass with large inventories is used whenever possible, and appropriate combinations are made to correct for off-axis chromatic aberration.

[0033] Specifically, the first plano-convex lens 11 , the first biconcave lens 12 , the first meniscus lens 13 , the first biconvex lens 14 , the second biconvex lens 15 , the second meniscus lens 16 and the third meniscus lens 17 are all made of CDGM (Chengdu Guangming Optoelectronics Co., Ltd.) commonly used large-diameter glass materials.

[0034] Specifically, the air gap between the first plano-convex lens 11 and the first biconcave lens 12 is 16.58-16.59 mm, preferably 16.58 mm; the air gap between the first biconcave lens 12 and the first meniscus lens 13 is 17.58-17.59 mm, preferably 17.59 mm; the air gap between the first meniscus lens 13 and the first biconvex lens 14 is 1.00-1.01 mm, preferably 1.01 mm; the air gap between the first biconvex lens 14 and the second biconvex lens 15 is 36.26-36.27 mm, preferably 36.27 mm; the air gap between the second biconvex lens 15 and the second meniscus lens 16 is 41.84-41.85 mm, preferably 41.85 mm; the air gap between the second meniscus lens 16 and the third meniscus lens 17 is 51.82-51.83 mm, preferably 51.83 mm.

[0035] The above-mentioned specific air gap values ​​are usually set for the following reasons: through precise calculation and experimental optimization, various aberrations are corrected at these specific gaps to achieve the best imaging quality; in order to obtain the required system focal length and magnification, these gap values ​​are determined through optical design and simulation; it helps to reduce chromatic aberration when light of different wavelengths passes through, making the imaging more accurate in color; according to the required field of view range and imaging clarity requirements, uniform imaging and clear performance of the entire field of view can be achieved by adjusting the gap.

[0036] Specifically, the refractive index and Abbe number corresponding to each lens in the objective lens group 10 meet the following conditions: 1.729≤n1, 54.685≤v1; 1.672≤n2, 32.171≤v2; 1.620≤n3, 60.339≤v3; 1.620≤n4, 60.339≤v4; 1.487≤n5, 70.440≤v5; 1.755≤n6, 27.530≤v6; 1.620≤n7, 60.339≤v7;

[0037] Among them, n1, n2, n3, n4, n5, n6, and n7 are the refractive indices of the first plano-convex lens 11, the first biconcave lens 12, the first meniscus lens 13, the first biconvex lens 14, the second biconvex lens 15, the second meniscus lens 16, and the third meniscus lens 17 respectively; v1, v2, v3, v4, v5, v6, and v7 are the Abbe numbers of the first plano-convex lens 11, the first biconcave lens 12, the first meniscus lens 13, the first biconvex lens 14, the second biconvex lens 15, the second meniscus lens 16, and the third meniscus lens 17 respectively.

[0038] Furthermore, the specific numerical ranges for the refractive index (n) and Abbe number (v) of each lens in the objective lens assembly 10 are generally set for the following reasons: the Abbe number reflects the material's ability to correct chromatic aberration. Different Abbe number ranges help better control chromatic aberration throughout the optical system, thereby improving the color accuracy and clarity of the image; different combinations of refractive index and Abbe number can help correct various aberrations, such as spherical aberration, coma, and astigmatism. By setting a specific numerical range for each lens, the impact of aberrations can be minimized during imaging for the entire objective lens assembly 10; the specific refractive index range can determine the refraction and propagation characteristics of light in the lens, thereby affecting the system's optical performance parameters such as focal length, magnification, and field of view. By rationally selecting and combining lenses with different refractive indices and Abbe numbers, the performance of the optical system can be optimized.

[0039] Specifically, let the light be emitted from the uniform array light source of the light source assembly 30 through the objective lens assembly 10 toward the visual direction. The curvature radius of the concave surface through which the light passes is a positive number, and the curvature radius of the convex surface through which the light passes is a negative number. The curvature radius corresponding to each lens in the objective lens assembly 10 satisfies the following conditions:

[0040] The curvature radius of the first plano-convex lens 11 away from the first biconcave lens 12 is in the range of 220 to 230 mm, and the curvature radius of the first plano-convex lens 11 close to the first biconcave lens 12 is infinite (an infinite curvature radius is a plane, which is more conducive to the processing and assembly of glass); the curvature radius of the first biconcave lens 12 away from the first meniscus lens 13 is in the range of -180 to -190 mm, and the curvature radius of the first biconcave lens 12 close to the first meniscus lens 13 is in the range of 550 to 560 mm; the curvature radius of the first meniscus lens 13 away from the first biconvex lens 14 is in the range of -420 to -430 mm, and the curvature radius of the first meniscus lens 13 close to the first biconvex lens 14 is in the range of -170 to -180 mm; the curvature radius of the first biconvex lens 14 away from the second biconvex lens 15 is in the range of The curvature radius of the first biconvex lens 14 on the side close to the second biconvex lens 15 is in the range of 290~300mm, the curvature radius range of the first biconvex lens 14 on the side close to the second biconvex lens 15 is in the range of -600~-610mm; the curvature radius range of the second biconvex lens 15 on the side away from the second meniscus lens 16 is in the range of 930~940mm, and the curvature radius range of the second biconvex lens 15 on the side close to the second meniscus lens 16 is in the range of -310~-320mm; the curvature radius range of the second meniscus lens 16 on the side away from the third meniscus lens 17 is in the range of -200~-210mm, and the curvature radius range of the second meniscus lens 16 on the side close to the third meniscus lens 17 is in the range of -730~-740mm; the curvature radius range of the third meniscus lens 17 on the side away from the grating plate 20 is in the range of -140~-150mm, and the curvature radius range of the third meniscus lens 17 on the side close to the grating plate 20 is in the range of -570~-580mm.

[0041] Furthermore, the main reasons for setting the specific numerical range of the curvature radius of each lens in the objective lens group 10 are as follows: different combinations of curvature radii can effectively correct various optical aberrations, and by precisely controlling the curvature of the lens surface, light can be propagated in a more ideal manner when passing through the lens group, reducing the impact of aberrations on imaging quality; a specific curvature radius range helps to guide light to propagate along the designed path, thereby achieving the desired imaging effect, such as focal length, magnification, field of view, etc.; a reasonable curvature radius can adjust the focus and divergence of light, and improve the clarity, contrast and brightness uniformity of the imaging; the combination of the curvature radii of each lens enables the entire objective lens group 10 to achieve a balance in optical performance, ensuring stable and reliable imaging under different working conditions.

[0042] Specifically, the center thickness range of the first plano-convex lens 11 is 23 to 23.5 mm, preferably 23.3 mm; the center thickness of the first biconcave lens 12 is 15.0 to 15.5 mm, preferably 15 mm; the center thickness of the first meniscus lens 13 is 29.0 to 29.5 mm, preferably 29.5 mm; the center thickness of the first biconvex lens 14 is 49.0 to 49.5 mm, preferably 49 mm; the center thickness range of the second biconvex lens 15 is 48 to 48.5 mm, preferably 48.2 mm; the center thickness range of the second meniscus lens 16 is 18 to 18.5 mm, preferably 18 mm; the center thickness range of the third meniscus lens 17 is 20 to 20.5 mm, preferably 20 mm.

[0043] Furthermore, the main reasons for setting the center thickness range and preferred value of the radius of curvature of each lens in the objective lens assembly 10 are as follows: different center thicknesses affect the refractive power and aberration correction effect of the lens. Through a specific thickness range and preferred value, better light refraction and focusing can be achieved, thereby improving imaging quality and reducing aberrations; a suitable center thickness can ensure the mechanical strength of the lens during use, enabling it to withstand certain external forces and environmental influences, not easily deformed or damaged, and increasing the stability and reliability of the system; in actual production and assembly processes, a certain thickness range is more convenient for processing and installation, while also controlling costs and improving production efficiency; according to the design requirements of the entire optical system, it is necessary to consider the weight and space occupied by the lens, and a reasonable center thickness helps meet the lightweight and compact requirements of the system; in certain working environments, the lens may be affected by temperature changes, and an appropriate center thickness helps to ensure the thermal stability of the lens and reduce the changes in optical performance caused by temperature changes.

[0044] Specifically, the distance between the edge of the third meniscus lens 17 and the graticule 20 is 15 to 16 mm; this distance helps to ensure that when light propagates from the third meniscus lens 17 to the graticule 20, a clear and accurate image can be formed, reducing the effects of aberration and distortion.

[0045] In Example 1 of the present invention, the specific parameters of each lens in the objective lens group 10 are shown in Table 1 below:

[0046] Table 1

[0047]

[0048] Specifically, the objective lens assembly 10 has a focal length of 260 mm, an exit pupil distance of 60-61 mm, an exit pupil diameter of 80 mm, a full field of view of 63°, an operating wavelength range of 0.486-0.656 μm, a maximum distortion of 0.11%, and a total optical length of 443.13 mm. A stop is also provided at the exit pupil diameter of the objective lens assembly 10.

[0049] Furthermore, the focal length determines the collimator's ability to converge or diverge light, affecting the size and clarity of the image. The exit pupil distance refers to the distance between the eye and the exit pupil, which allows a clear image to be seen at the exit pupil position. A suitable exit pupil distance facilitates the observer's use and reduces the difficulty of eye positioning. The larger the exit pupil diameter, the more light enters the eye during observation, making the image appear brighter, and making observation more comfortable in low-light environments. A full field of view of 63° represents the maximum angular range that the collimator can observe, and a larger field of view can cover a wider area. The operating band defines the wavelength range of light waves in which the collimator can effectively operate, and good optical performance can be guaranteed within this range. Low distortion means that the shape distortion of the image is minimal, which can more realistically reflect the shape and characteristics of the observed object. The total optical length reflects the length of the entire objective lens assembly 10 along the optical axis and has a significant impact on the installation and layout of the system.

[0050] Please continue reading Figures 6A to 6B The high-precision, large-field-of-view collimator further includes a fixing assembly 40, which includes a front fixing member 42, a middle fixing member 43, and a rear fixing member 44 connected in sequence from the visual direction to the light source assembly 30;

[0051] Among them, the front fixing member 42 is used to fix the first plano-convex lens 11, the first biconcave lens 12 and the first meniscus lens 13; the middle fixing member 43 is used to fix the first biconvex lens 14 and the second biconvex lens 15; the rear fixing member 44 is used to fix the second meniscus lens 16, the third meniscus lens 17, the dividing plate 20 and the light source assembly 30.

[0052] Specifically, the front fixing member 42, the middle fixing member 43 and the rear fixing member 44 are fixedly connected by two upper and lower locking screws; a mirror cover assembly 50 is provided on the outer side of the front fixing member 42 close to the visual direction, and the mirror cover assembly 50 includes a lens cover and a handle. The lens cover is used to protect the outer surface of the first plano-convex lens 11.

[0053] Specifically, the front fixing member 42 includes a first spacer 421, a first pressure ring 422, a first objective lens frame 423, a second pressure ring 424, a third pressure ring 425, and a front lens tube 426; wherein, the first spacer 421 is provided between the first plano-convex lens 11 and the first biconcave lens 12, and the first pressure ring 422 is provided on the first plano-convex lens 11 near the exit pupil direction, and the first plano-convex lens 11 is fixed in the groove of the first spacer 421 by means of a threaded connection. A first objective lens frame 423 is provided between the first biconcave lens 12 and the first meniscus lens 13, and the first objective lens frame 423 and the first spacer 421 are used to fix the first biconcave lens 12. The first spacer 421 is provided with a second pressure ring 424 on the side close to the exit pupil, and the first plano-convex lens 11 and the first biconcave lens 12 are fixed to the first objective lens frame 423 by means of a threaded connection. A first objective lens frame 423 and a front lens tube 426 are provided on both sides of the first meniscus lens 13. A third pressure ring 425 is provided on the side of the first objective lens frame 423 close to the exit pupil, and the first meniscus lens 13 is fixed to the front lens tube 426 by a threaded connection.

[0054] Specifically, the middle fixing member 43 includes a second spacer ring 431, a fourth pressure ring 432 and a middle mirror tube 433; wherein, a second spacer ring 431 is provided between the first biconvex lens 14 and the second biconvex lens 15, and a fourth pressure ring 432 is provided on the side of the first biconvex lens 14 close to the exit pupil, and the first biconvex lens 14 and the second biconvex lens 15 are fixed on the middle mirror tube 433 by a threaded connection.

[0055] Specifically, the rear fixing member 44 includes a second objective lens frame 441, a fifth pressing ring 444, a third objective lens frame 443, a sixth pressing ring 442, a rear lens tube 445, a seventh pressing ring 446, an eighth pressing ring 447, a lens tube rear pressing ring 448, a reticle frame 449, and a light source cover 45. The second objective lens frame 441 is provided on the convex side of the second meniscus lens 16, and the fifth pressing ring 444 is provided on the concave side. The second meniscus lens 16 is fixed in the second objective lens frame 441 by a threaded connection. The third meniscus lens 17 is provided on the convex side of the third objective lens 17. The third meniscus lens 17 is pressed between the second objective lens frame 441 and the third objective lens frame 443 by the sixth pressing ring 442. The rear lens tube 445 is provided on the outside of the third objective lens frame 443. The rear lens tube 445 is pressed by the lens tube rear pressing ring 448. The second and third meniscus lenses 16 and 17 are fixed in the rear lens frame by two threaded holes. The reticle 20 is fixed to the reticle frame 449 by the seventh pressure ring 446 and the eighth pressure ring 447 respectively. The front surface of the reticle 20 coincides with the image plane of the optical system of the above-mentioned high-precision large-field-of-view parallel light tube. At the same time, the reticle frame 449 and the rear pressure ring 448 of the lens tube are limited by two upper and lower flat-head screws.

[0056] Specifically, the fixing assembly 40 further includes a roll block 41 located at the bottom of the middle fixing member 43. The roll block 41 is mainly used to ensure the high positioning accuracy requirements of the optical system integration of the above-mentioned high-precision large-field-of-view collimator and achieve precise alignment of the optical axis.

[0057] In Example 1 of the present invention, the reticle 20 is located between the objective lens assembly 10 and the light source assembly 30; the reticle 20 is usually engraved with precise scales, lines or patterns, which can be used to measure parameters such as angles, distances, and positions, providing a reference for the calibration and measurement of the optical system of the above-mentioned high-precision large-field-of-view collimator.

[0058] In embodiment 1 of the present invention, the light source assembly 30 includes an acrylic plate 31, a uniform array light source 32 and a power module 33, which are arranged in sequence from the visual direction to the light source assembly 30. The acrylic plate 31, the uniform array light source 32 and the power module 33 are all fixed in the light source cover 45 in the rear fixing component 44.

[0059] Specifically, the uniform array light source 32 is preferably a 220V / 50Hz Φ345 uniform array light source, and the acrylic plate 31 located at the front end of the uniform array light source 32 is used for light uniformity; the outer shell of the light source cover 45 has six threaded holes, which are fastened to the rear mirror tube 445 by screws.

[0060] Specifically, the fixing assembly 40 in Example 1 of the present invention is made of aluminum alloy, which is easy to process and has good manufacturability. The overall structure of the light pipe is highly stable and easy to assemble, which can meet actual use requirements.

[0061] See also Figure 2 , Figure 2 Schematic diagram of the optical system light path of the high-precision large-field collimator provided in Example 1 of the present invention; wherein Figure 2 It can be seen that the illumination light starts from the light source assembly 30, passes through the objective lens group 10 and reaches the visual area, and is converted into parallel light.

[0062] See also Figures 3A to 3E , Figures 3A to 3E is a light fan diagram of a high-precision, large-field-of-view collimator provided by Example 1 of the present invention at different object plane angles; wherein, Figures 3A to 3E It can be seen that the optical system of the high-precision, large-field-of-view collimator provided in Example 1 of the present invention has relatively small off-axis aberration and chromatic aberration.

[0063] See also Figure 4 , Figure 4 is a spot diagram of a high-precision, large-field collimator provided by Example 1 of the present invention; wherein Figure 4It can be seen that the root mean square (RMS) radius of the central field of view of the optical system of the high-precision, large-field-of-view collimator provided in Example 1 of the present invention is 38 μm, and the root mean square radius of the edge field of view is 54 μm; this shows that in this optical system, both the central field of view and the edge field of view have good imaging clarity and accuracy, and the imaging quality of the central field of view is better than that of the edge field of view.

[0064] See also Figure 5 , Figure 5 is a field curvature and distortion diagram of a high-precision, large-field collimator provided by Example 1 of the present invention; wherein, Figure 5 It can be seen that the field curvature and astigmatism of the high-precision large-field-of-view collimator provided by Example 1 of the present invention are both less than 1 mm in the full field of view, and the maximum distortion is 0.11%.

[0065] Specifically, "field curvature and astigmatism are less than 1mm in the entire field of view" means that the two aberrations of field curvature and astigmatism are well controlled within the entire observable field of view. Field curvature will cause the image plane to be non-planar, while astigmatism will cause light rays in different directions to focus on different points. A value of less than 1mm means that the curvature of the image plane and the deviation in the focusing of light rays in different directions are small, thus enabling a relatively smooth and clear image to be obtained. "The maximum distortion is 0.11%" indicates that the degree of deformation of the image is very small. Distortion will cause straight lines in the image to bend or change their proportions. The low distortion value of 0.11% ensures that the shape of the image can highly accurately reflect the shape of the actual object, which is very important for applications that require precise measurement and observation.

[0066] Taken together, these parameters show that the collimator can provide high-quality, low-distortion imaging within a large field of view, and is suitable for tasks such as measurement, detection, and observation that require high optical performance.

[0067] In summary, compared with the prior art, the present invention has the following advantages:

[0068] The technical solution of the present invention completes the development and processing of high-precision, large-aperture, and large-field-of-view collimators, and meets the design index requirements. The product's full field of view angle reaches 63°, the maximum distortion of the optical system is 0.11%, and the 20-line accuracy of the product reticle is less than 2', meeting the use requirements of high-precision, large-field-of-view products and providing a wider test range for optical performance testing of aviation head-up displays and helmet-mounted sights. The optical elements of the large-field-of-view collimator are made of conventional large-aperture glass grades from domestic glass manufacturers, which can effectively avoid the optical elements being made through a glass melting process with a low conversion rate, thereby controlling costs during the processing and effectively correcting the system's off-axis chromatic aberration within the visible light range.

[0069] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For any details not described in individual embodiments, reference may be made to the description in other embodiments.

[0070] The above embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A high-precision, large-field-of-view collimator, characterized in that: The objective lens assembly comprises an objective lens group, a reticle, and a light source assembly arranged in sequence. The objective lens group is arranged in sequence from the visual direction to the light source assembly as a first plano-convex lens, a first biconcave lens, a first meniscus lens, a first biconvex lens, a second biconvex lens, a second meniscus lens, and a third meniscus lens. The refractive index and Abbe number of each lens in the objective lens group meet the following conditions: 1.729≤n1, 54.685≤v1; 1.672≤n2, 32.171≤v2; 1.620≤n3, 60.339≤v3; 1.620≤n4, 60.339≤v4; 1.487≤n5, 70.440≤v5; 1.755≤n6, 27.530≤v6; 1.620≤n7, 60.339≤v7; Among them, n1, n2, n3, n4, n5, n6, and n7 are the refractive indices of the first plano-convex lens, the first biconcave lens, the first meniscus lens, the first biconvex lens, the second biconvex lens, the second meniscus lens, and the third meniscus lens respectively; v1, v2, v3, v4, v5, v6, and v7 are the Abbe numbers of the first plano-convex lens, the first biconcave lens, the first meniscus lens, the first biconvex lens, the second biconvex lens, the second meniscus lens, and the third meniscus lens respectively.

2. The high-precision, large-field-of-view collimator according to claim 1, characterized in that: The first plano-convex lens, the first biconcave lens, the first meniscus lens, the first biconvex lens, the second biconvex lens, the second meniscus lens and the third meniscus lens are all made of large-diameter glass materials.

3. The high-precision, large-field-of-view collimator according to claim 1, characterized in that: The air gap between the first plano-convex lens and the first biconcave lens is 16.58~16.59mm; the air gap between the first biconcave lens and the first meniscus lens is 17.58~17.59mm; the air gap between the first meniscus lens and the first biconvex lens is 1.00~1.01mm; the air gap between the first biconvex lens and the second biconvex lens is 36.26~36.27mm; the air gap between the second biconvex lens and the second meniscus lens is 41.84~41.85mm; the air gap between the second meniscus lens and the third meniscus lens is 51.82~51.83mm.

4. The high-precision, large-field-of-view collimator according to claim 1, characterized in that: Let the light be emitted from the uniform array light source of the light source assembly through the objective lens group toward the visual direction. The curvature radius of the concave surface through which the light passes is a positive number, and the curvature radius of the convex surface through which the light passes is a negative number. The curvature radius corresponding to each lens in the objective lens group satisfies the following conditions: The curvature radius of the first plano-convex lens away from the first biconcave lens is in the range of 220 to 230 mm, and the curvature radius of the first plano-convex lens close to the first biconcave lens is infinite; the curvature radius of the first biconcave lens away from the first meniscus lens is in the range of -180 to -190 mm, and the curvature radius of the first biconcave lens close to the first meniscus lens is in the range of 550 to 560 mm; the curvature radius of the first meniscus lens away from the first biconvex lens is in the range of -420 to -430 mm, and the curvature radius of the first meniscus lens close to the first biconvex lens is in the range of -170 to -180 mm; the curvature radius of the first biconvex lens away from the second biconvex lens is in the range of 290 to 300 mm, and the first The curvature radius of the biconvex lens on the side close to the second biconvex lens is in the range of -600~-610mm; the curvature radius of the second biconvex lens on the side away from the second meniscus lens is in the range of 930~940mm, and the curvature radius of the second biconvex lens on the side close to the second meniscus lens is in the range of -310~-320mm; the curvature radius of the second meniscus lens on the side away from the third meniscus lens is in the range of -200~-210mm, and the curvature radius of the second meniscus lens on the side close to the third meniscus lens is in the range of -730~-740mm; the curvature radius of the third meniscus lens on the side away from the graticule is in the range of -140~-150mm, and the curvature radius of the third meniscus lens on the side close to the graticule is in the range of -570~-580mm.

5. The high-precision, large-field-of-view collimator according to claim 1, characterized in that: The center thickness of the first plano-convex lens ranges from 23 to 23.5 mm, the center thickness of the first biconcave lens ranges from 15.0 to 15.5 mm, the center thickness of the first meniscus lens ranges from 29.0 to 29.5 mm, the center thickness of the first biconvex lens ranges from 49.0 to 49.5 mm, the center thickness of the second biconvex lens ranges from 48 to 48.5 mm, the center thickness of the second meniscus lens ranges from 18 to 18.5 mm, and the center thickness of the third meniscus lens ranges from 20 to 20.5 mm; the distance between the edge of the third meniscus lens and the graticule is 15 to 16 mm.

6. The high-precision, large-field-of-view collimator according to any one of claims 2 to 5, characterized in that: The focal length of the objective lens group is 260 mm, the exit pupil distance is 60-61 mm, the exit pupil diameter is 80 mm, the full field of view angle is 63°, the working band is 0.486-0.656 μm, the maximum distortion is 0.11%, and the total optical length is 443.13 mm.

7. The high-precision, large-field-of-view collimator according to claim 1, characterized in that: An aperture is also provided at the exit pupil diameter of the objective lens group.

8. The high-precision, large-field-of-view collimator according to claim 1, characterized in that: The high-precision, large-field-of-view collimator further includes a fixing assembly, which includes a front fixing member, a middle fixing member, and a rear fixing member connected in sequence from the visual direction to the light source assembly. Among them, the front fixing member is used to fix the first plano-convex lens, the first biconcave lens and the first meniscus lens; the middle fixing member is used to fix the first biconvex lens and the second biconvex lens; the rear fixing member is used to fix the second meniscus lens, the third meniscus lens, the graticule and the light source assembly.

9. The high-precision, large-field-of-view collimator according to claim 8, characterized in that: The front fixing member, the middle fixing member and the rear fixing member are fixedly connected by tightening screws; a mirror cover member is provided on the outer side of the front fixing member close to the visual direction.

10. The high-precision, large-field-of-view collimator according to claim 8, characterized in that: The light source assembly includes an acrylic plate, a uniform array light source and a power module arranged in sequence from the visual direction to the light source assembly direction. The acrylic plate, the uniform array light source and the power module are all fixed in the rear fixing component.

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