High-precision large-view-field collimator

Abstract

The invention provides a high-precision large-field-of-view collimator. An optical system of the high-precision large-view-field collimator is sequentially provided with 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 reticle, an acrylic plate and a uniform area array light source in the direction from human eyes to a light source. The optical elements of the optical system all adopt CDGM conventional large-caliber glass, so that a melting process with low conversion rate is avoided during glass processing, and the cost is effectively reduced. The full-field angle of the optical system is 63 degrees, the maximum distortion is smaller than 0.11%, the optical system is matched with an existing optical glass material to correct chromatic aberration in the visible light range, the scribing precision of a collimator reticle is lower than 2 ', and the use requirements of high-precision and large-field products can be met.

Description

Technical Field

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

[0002] A collimator is an optical testing instrument, usually composed of a lens group, a graticule and a light source. Its main function is to generate parallel light through a specific optical system to simulate an infinitely distant target. Optical elements such as graticules and star point plates are placed on the focal plane of the collimator lens group to test the optical performance of the optical system being tested.

[0003] Due to the current needs of astronomical observation and space exploration, space-to-earth observation, national defense and security, optical systems with higher resolution have become the mainstream development direction, so optical systems with large apertures and large fields of view have been developed accordingly. 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 the development of 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 40°~50°, and the field of view test accuracy is 2′~3′, which is difficult to 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 the collimator. 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 prior art collimators, such as small field-of-view angle range and low field-of-view test accuracy.

[0005] In order to solve the above technical problems, the present invention provides a high-precision large-field collimator, comprising an objective lens group, a graticule 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 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; the refractive index and Abbe number corresponding to each lens in the objective lens group satisfy the following conditions: 1.729≤n 1 , 54.685≤v 1 ; 1.672≤n 2 , 32.171≤v 2 ; 1.620≤n 3 ,60.339≤v 3 ; 1.620≤n 4 ,60.339≤v 4 ; 1.487≤n 5 , 70.440≤v 5 ; 1.755≤n 6 , 27.530≤v 6 ; 1.620≤n7 ,60.339≤v 7 ; where n 1 、n 2 、n 3 、n 4 、n 5 、n 6 、n 7 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 in order; v 1 、v 2 、v 3 、v 4 、v 5 、v 6 、v 7 They 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.

[0006] 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 also provided at the exit pupil diameter of the objective lens group.

[0007] 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; the air gap between the second meniscus lens and the third meniscus lens is 51.82-51.83 mm.

[0008] Preferably, light is emitted from the uniform array light source of the light source assembly to the visual direction through the objective lens group, 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, and 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 biconvex lens is in the range of 150 to 200 mm. The curvature radius range of the lens close to the second biconvex lens side is -600~-610mm; the curvature radius range of the second biconvex lens away from the second meniscus lens side is 930~940mm, and the curvature radius range of the second biconvex lens close to the second meniscus lens side is -310~-320mm; the curvature radius range of the second meniscus lens away from the third meniscus lens side is -200~-210mm, and the curvature radius range of the second meniscus lens close to the third meniscus lens side is -730~-740mm; the curvature radius range of the third meniscus lens away from the graticule side is -140~-150mm, and the curvature radius range of the third meniscus lens close to the graticule side is -570~-580mm.

[0009] 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.

[0010] 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.

[0011] Preferably, the high-precision large-field collimator further comprises a fixing assembly, which comprises 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 direction; 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.

[0012] 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.

[0013] Preferably, the light source assembly comprises an acrylic plate, a uniform array light source and a power module which are 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.

[0014] 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 system optical power, causes a large deflection of off-axis light rays, 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 The invention provides 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 reasonably controls the refractive index and Abbe number of each lens, so that the optical objective lens group has good correction of chromatic aberration, astigmatism, coma, field curvature and distortion, 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

[0015] 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; Figure 2 This is a schematic diagram of the optical path of the optical system of the high-precision large-field collimator provided in Example 1 of the present invention; FIG. 3A to FIG. 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; Figure 4 is a spot diagram of a high-precision, large-field-of-view collimator provided in Example 1 of the present invention; 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; FIG. 6A to FIG. 6Bis 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; 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 - graticule; 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 Mirror frame; 424 - second pressure ring; 425 - third pressure ring; 426 - front mirror tube; 43 - middle fixing member; 431 - second spacer; 432 - fourth pressure ring; 433 - middle mirror tube; 44 - rear fixing member; 441 - second objective lens frame; 442 - sixth pressure ring; 443 - third objective lens frame; 444 - fifth pressure ring; 445 - rear mirror tube; 446 - seventh pressure ring; 447 - eighth pressure ring; 448 - rear pressure ring of mirror tube; 449 - reticle frame; 45 - light source cover; 50 - mirror cover assembly. DETAILED DESCRIPTION

[0016] 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 described embodiments 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 creative work are within the scope of protection of the present invention.

[0017] 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 detection with larger aperture, field of view and higher precision.

[0018] The technical solution of the present invention is now described in conjunction with specific embodiments.

[0019] Embodiment 1: See also Figure 1 , FIG. 6A to FIG. 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; FIG. 6A to FIG. 6B It 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 in 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 direction of 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.

[0020] In the embodiment of the present invention, the objective lens group 10 has the following important functions: light collimation: the divergent light from the light source assembly 30 is converged and collimated to be 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 resolution ability of the system 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 in the entire field of view to avoid uneven brightness.

[0021] Specifically, the first plano-convex lens 11 of the objective lens group 10 bears the system optical focal length, causes a larger deflection of the off-axis light, and constrains the aperture of the 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 the 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 system light aperture; 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.

[0022] Due to the limitations of the physical and chemical properties of glass itself, when domestic glass processing manufacturers process lenses with a diameter exceeding 160 mm, except for a few brands of glass blanks that have a large inventory, the remaining brands all need to use a melting process to melt a large amount of glass blanks to the required size. Due to the low conversion efficiency of the melting process, the processing of each large-diameter glass will result in a large amount of blank glass being wasted, which greatly increases the processing cost. In order to ensure low cost, the present invention needs to avoid using low-dispersion glass that deviates from the glass dispersion curve during the design stage, use conventional glass with a large inventory as much as possible, and make reasonable combinations to correct off-axis chromatic aberration.

[0023] 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 large-diameter glass materials commonly used by CDGM (Chengdu Guangming Optoelectronics Co., Ltd.).

[0024] 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.

[0025] The above-mentioned specific air spacing numerical settings are usually based on the following reasons: through precise calculation and experimental optimization, various aberrations are corrected with these specific spacings to achieve the best imaging quality; in order to obtain the required system focal length and magnification, these spacing 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 spacing.

[0026] Specifically, the refractive index and Abbe number of each lens in the objective lens group 10 satisfy the following conditions: 1.729≤n 1 , 54.685≤v 1 ; 1.672≤n 2 , 32.171≤v 2 ; 1.620≤n 3 ,60.339≤v 3 ; 1.620≤n 4 ,60.339≤v 4 ; 1.487≤n 5 , 70.440≤v 5 ; 1.755≤n 6 , 27.530≤v 6 ; 1.620≤n 7 ,60.339≤v 7 ; Among them, n 1 、n 2 、n 3 、n 4 、n 5 、n 6 、n 7are 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 in order; v 1 、v 2 、v 3 、v 4 、v 5 、v 6 、v 7 They 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.

[0027] Furthermore, the above-mentioned specific numerical ranges of the refractive index (n) and Abbe number (v) of each lens in the objective lens group 10 are usually set for the following reasons: the Abbe number reflects the material's ability to correct chromatic aberration, and different Abbe number ranges help to better control chromatic aberration in the entire optical system, thereby improving the color accuracy and clarity of imaging; different combinations of refractive index and Abbe number can help correct various aberrations, such as spherical aberration, coma, astigmatism, etc. By setting a specific numerical range for each lens, the entire objective lens group 10 can minimize the impact of aberrations when imaging; a specific refractive index range can determine the refraction and propagation characteristics of light in the lens, thereby affecting the system's focal length, magnification, field of view and other optical performance parameters. By reasonably selecting and matching lenses with different refractive indices and Abbe numbers, the performance of the optical system can be optimized.

[0028] Specifically, let the light be emitted from the uniform array light source of the light source assembly 30 through the objective lens group 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, and the curvature radius corresponding to each lens in the objective lens group 10 satisfies the following conditions: 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 (the curvature radius is infinite, that is, a plane, and a plane 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 to 300mm, the curvature radius of the first biconvex lens 14 on the side close to the second biconvex lens 15 is in the range of -600 to -610mm; the curvature radius of the second biconvex lens 15 on the side away from the second meniscus lens 16 is in the range of 930 to 940mm, and the curvature radius of the second biconvex lens 15 on the side close to the second meniscus lens 16 is in the range of -310 to -320mm; the curvature radius of the second meniscus lens 16 on the side away from the third meniscus lens 17 is in the range of -200 to -210mm, and the curvature radius of the second meniscus lens 16 on the side close to the third meniscus lens 17 is in the range of -730 to -740mm; the curvature radius of the third meniscus lens 17 on the side away from the grating plate 20 is in the range of -140 to -150mm, and the curvature radius of the third meniscus lens 17 on the side close to the grating plate 20 is in the range of -570 to -580mm.

[0029] Furthermore, the main reasons for setting the specific numerical range of the radius of curvature 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 accurately controlling the curvature of the lens surface, the 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 the 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 the 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.

[0030] 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.

[0031] Further, the main reasons for setting the center thickness range and preferred value of the radius of curvature of each lens in the objective lens group 10 are as follows: different center thicknesses will 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; the appropriate center thickness can ensure the mechanical strength of the lens during use, so that it can withstand certain external forces and environmental influences, is not easy to deform or damage, and increases the stability and reliability of the system; in the actual production and assembly process, a certain thickness range is more convenient for processing and installation, and can also control costs and improve 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 to meet the lightweight and compact requirements of the system; in some 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 changes in optical properties caused by temperature changes.

[0032] Specifically, the distance between the edge of the third meniscus lens 17 and the grating plate 20 is 15 to 16 mm; this distance helps to ensure that when light propagates from the third meniscus lens 17 to the grating plate 20, a clear and accurate image can be formed, reducing the effects of aberrations and distortions.

[0033] In Embodiment 1 of the present invention, specific parameters of each lens in the objective lens group 10 are shown in Table 1 below: Table 1

[0034] Specifically, the focal length of the objective lens group 10 is 260 mm, the pupil distance is 60-61 mm, the 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. A stop is also provided at the pupil diameter of the objective lens group 10.

[0035] Furthermore, the focal length determines the ability of the collimator 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 at which a clear image can be seen at the exit pupil position. A suitable exit pupil distance is convenient for the observer to use and reduces the difficulty of eye positioning; the larger the exit pupil diameter, the more light enters the eye during observation, and the image looks brighter, especially in a low-light environment. The full field of view of 63° represents the maximum angle range that the collimator can observe, and a larger field of view can cover a wider area; the working band limits the wavelength range of light waves in which the collimator can effectively work, and better optical performance can be guaranteed within this range; low distortion means that the shape distortion of the image is very small, which can more realistically reflect the shape and characteristics of the observed object; the total optical length reflects the length dimension of the entire objective lens group 10 in the direction of the optical axis, which has an important impact on the installation and layout of the system.

[0036] Please continue reading FIG. 6A to FIG. 6B The high-precision large-field collimator further comprises a fixing assembly 40, which comprises a front fixing member 42, a middle fixing member 43 and a rear fixing member 44 which are sequentially connected from the visual direction to the direction of the light source assembly 30; Among them, the front fixing component 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 component 43 is used to fix the first biconvex lens 14 and the second biconvex lens 15; the rear fixing component 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.

[0037] 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, and the lens cover is used to protect the outer surface of the first plano-convex lens 11.

[0038] 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, a first spacer 421 is provided between the first plano-convex lens 11 and the first biconcave lens 12, and a first pressure ring 422 is provided near the exit pupil direction of the first plano-convex lens 11, 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, and a second pressure ring 424 is provided near the exit pupil side of the first spacer 421, and the first plano-convex lens 11 and the first biconcave lens 12 are fixed on 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 respectively provided on both sides of the first meniscus lens 13. A third pressing 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 threaded connection.

[0039] 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 to the middle mirror tube 433 by means of threaded connection.

[0040] 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 graticule frame 449 and a light source cover 45; wherein, 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, and the second meniscus lens 16 is fixed in the second objective lens frame 441 by threaded connection. The third meniscus lens 17 is provided on the convex side of the third objective lens 17, and 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 outside the third objective lens frame 443, and the second meniscus lens 16 and the third meniscus lens 17 are fixed in the rear lens frame by the lens tube rear pressing ring 448, and the two threaded holes are fixed. The graticule plate 20 is fixed to the graticule plate frame 449 by the seventh pressing ring 446 and the eighth pressing ring 447 respectively. The front surface of the graticule plate 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 graticule plate frame 449 and the rear pressing ring 448 of the mirror tube are limited by two upper and lower flat-head screws.

[0041] Specifically, the fixing assembly 40 also includes a rolling block 41 located at the bottom of the middle fixing member 43. The rolling block 41 is mainly used to ensure the high positioning accuracy requirement of the optical system integration of the above-mentioned high-precision large-field collimator to achieve precise alignment of the optical axis.

[0042] In Embodiment 1 of the present invention, graticule 20 is located between objective lens assembly 10 and light source assembly 30; graticule 20 is usually engraved with precise scales, lines or patterns, which can be used to measure parameters such as angles, distances, and positions, and provide a reference for the calibration and measurement of the optical system of the above-mentioned high-precision large-field-of-view collimator.

[0043] 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 direction of 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 .

[0044] 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.

[0045] Specifically, the fixing assembly 40 in Embodiment 1 of the present invention is made of aluminum alloy material, which is easy to process and has good processability, and the overall structure of the light pipe is highly stable and easy to assemble, thus meeting actual use requirements.

[0046] See also Figure 2 , Figure 2 Schematic diagram of the optical system optical 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.

[0047] See also FIG. 3A to FIG. 3E , FIG. 3A to FIG. 3E is a light fan diagram of a high-precision large-field collimator provided by Embodiment 1 of the present invention at different object plane angles; wherein, FIG. 3A to FIG. 3E It can be seen that the optical system of the high-precision large-field collimator provided in Example 1 of the present invention has relatively small off-axis aberration and chromatic aberration.

[0048] 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.

[0049] See also Figure 5 , Figure 5 is a field curvature and distortion diagram of a high-precision large-field collimator provided in 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%.

[0050] 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-flat, while astigmatism will cause light rays in different directions to focus on different points. A value less than 1mm means that the curvature of the image plane and the deviation of the focusing of light rays in different directions are small, so that a relatively smooth and clear image can be obtained. "The maximum distortion is 0.11%" means 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.

[0051] Taken together, these parameters show that the collimator can provide high-quality, low-distortion imaging over a large field of view, and is suitable for tasks such as measurement, detection, and observation that require high optical performance.

[0052] In summary, compared with the prior art, the present invention has the following advantages: 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 full field of view of the product reaches 63°, the maximum distortion of the optical system is 0.11%, and the accuracy of the 20 lines of the product graticule is less than 2′, which meets the use requirements of high-precision and large-field-of-view products, and can provide a wider test range for the optical performance testing of aviation head-up displays and helmet sights. In addition, the optical elements of the large-field-of-view collimator adopt the conventional large-aperture glass grades of 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 process, and can effectively correct the system's off-axis chromatic aberration within the visible light range.

[0053] 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 matters that are not described in detail in some embodiments, reference may be made to the description in other embodiments.

[0054] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A high-precision, large-field collimator, characterized in that: The objective lens group includes an objective lens group, a graticule 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 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, and the refractive index and Abbe number corresponding to 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 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 collimator according to claim 1, characterized in that: The air gap between the first plano-convex lens and the first biconcave lens is 16.58-16.59 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; the air gap between the second meniscus lens and the third meniscus lens is 51.82-51.83 mm.

4. The high-precision large-field 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 range of the biconvex lens close to the second biconvex lens side is -600~-610mm; the curvature radius range of the second biconvex lens away from the second meniscus lens side is 930~940mm, and the curvature radius range of the second biconvex lens close to the second meniscus lens side is -310~-320mm; the curvature radius range of the second meniscus lens away from the third meniscus lens side is -200~-210mm, and the curvature radius range of the second meniscus lens close to the third meniscus lens side is -730~-740mm; the curvature radius range of the third meniscus lens away from the grating plate side is -140~-150mm, and the curvature radius range of the third meniscus lens close to the grating plate side is -570~-580mm.

5. The high-precision large-field 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 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 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 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 collimator according to claim 1, characterized in that: The high-precision large-field collimator also 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 direction; 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 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 means of a locking screw; 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 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 which are 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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