Compact multi-time continuous zooming sighting telescope optical system

Abstract

The invention discloses a compact multi-time continuous zooming optical system for a sighting telescope. The compact multi-time continuous zooming optical system comprises an objective lens group, a relay image rotation group and an eyepiece group, the objective lens group comprises a first biconvex lens, a second biconvex lens, a first biconcave lens and a third biconvex lens which are sequentially arranged from the object space to the image space; the relay image rotation group comprises a first positive meniscus lens, a fourth biconvex lens, a first negative meniscus lens, a second negative meniscus lens, a fifth biconvex lens, a second biconcave lens and a second positive meniscus lens which are sequentially arranged from the object side to the image side; and the eyepiece group comprises a third positive meniscus lens, a third biconcave lens, a sixth biconvex lens and a fourth positive meniscus lens which are sequentially arranged from the object space to the image space. According to the invention, 1-12 times of continuous zooming is realized under a compact structure, meanwhile, the problems of large pupil distance fluctuation range and overlarge cam curve pressure lead angle are solved, and in addition, the aberration compensation optimization design method is used, so that the distortion, field curvature and chromatic aberration of a sighting telescope system are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sight imaging, and particularly to a compact multi-fold continuous zoom sight optical system. Background Art

[0002] In the fields of military reconnaissance, sniper aiming, and target viewing equipment, etc., the optical zoom ability of a sight directly affects its observation range, target recognition accuracy, and combat adaptability. Traditional sights mostly adopt fixed magnification or switchable zoom designs, but there are problems such as limited zoom range and the need to interrupt observation during the switching process. In recent years, continuous zoom optical systems have become a research hotspot due to their advantages of smooth magnification transition and no need for refocusing. However, achieving a high zoom ratio still faces significant challenges. On the one hand, during the zoom process, it is necessary to synchronously compensate for image plane offset and aberration changes, resulting in the complication of the optical structure. On the other hand, existing systems often increase the number of lens groups or introduce aspherical lenses to improve the zoom ratio, but this will bring problems such as increased volume and weight, strict assembly tolerance, and rising costs. For example, the zoom component with a three-element "positive-positive-negative" optical power disclosed in Chinese Patent CN117991482A achieves 6-fold zoom. Compared with the traditional two-element "positive-positive" optical power zoom component sight system, the increase in the number of lenses will lead to problems such as increased cost and system complication. The zoom component with a two-element "positive-positive" zoom power disclosed in Chinese Patent CN119394094A achieves 8-fold zoom, but the field curvature and distortion correction at the long focal length end are insufficient.

[0003] High zoom ratio sights are also prone to core problems such as difficult aberration correction, insufficient stability of the exit pupil distance, and mechanical jamming caused by excessive pressure angle of the cam curve in design and practical applications. Therefore, how to achieve high ratio continuous zoom in a compact structure while ensuring the stability of the exit pupil distance and excellent image quality across the entire field of view at each magnification remains a technical problem in this field. Summary of the Invention

[0004] Object of the Invention: The object of the present invention is to provide a compact multi-fold continuous zoom sight optical system; by using a two-element "positive-positive" optical power zoom component, it realizes 1 - 12-fold continuous zoom in a compact structure to solve the problems of large pupil distance fluctuation range and excessive pressure angle of the cam curve.

[0005] Technical Solution: The compact multi-fold continuous zoom sight optical system described in the present invention includes an objective lens group, a relay image rotation group, and an eyepiece group; the objective lens group includes a first double convex lens, a second double convex lens, a first double concave lens, and a third double convex lens arranged in sequence from the object side to the image side;

[0006] The relay image relay group includes a first positive meniscus lens, a fourth biconvex lens, a first negative meniscus lens, a second negative meniscus lens, a fifth biconvex lens, a second biconcave lens, and a second positive meniscus lens arranged in sequence from the object side to the image side;

[0007] The eyepiece group includes a third positive meniscus lens, a third biconcave lens, a sixth biconvex lens, and a fourth positive meniscus lens arranged in sequence from the object side to the image side.

[0008] Furthermore, a diaphragm is provided on the front surface of the first biconvex lens.

[0009] Furthermore, the second biconvex lens and the first biconcave lens form a first doublet lens, the fourth biconvex lens and the first negative meniscus lens form a second doublet lens, the second negative meniscus lens and the fifth biconvex lens form a third doublet lens, the second biconcave lens and the second positive meniscus lens form a fourth doublet lens, and the third biconcave lens and the sixth biconvex lens form a fifth doublet lens.

[0010] Furthermore, the image plane of the objective lens group is the first intermediate image plane of the sighting scope system, located between the third biconvex lens and the first positive meniscus lens.

[0011] Furthermore, the image plane of the relay image relay group is the second intermediate image plane of the sighting scope system, located between the fourth doublet lens and the third positive meniscus lens.

[0012] Furthermore, a reticle is provided at the second intermediate image plane, and the image-side focal plane of the reticle coincides with the second intermediate image plane of the sighting scope system.

[0013] Furthermore, the distance between the first biconvex lens and the first doublet lens is 0.5 mm, the distance between the first doublet lens and the third biconvex lens is 62.713 mm, and the distance between the third biconvex lens and the first intermediate image plane is 9.728 mm.

[0014] Furthermore, the distance between the first positive meniscus lens and the first intermediate image plane is 8.351 mm, the distance between the first positive meniscus lens and the second doublet lens is a variable distance d1, the distance between the second doublet lens and the third doublet lens is a variable distance d2, the distance between the third doublet lens and the fourth doublet lens is a variable distance d3, and the distance between the fourth doublet lens and the second intermediate image plane is 13.942 mm.

[0015] Furthermore, the variation ranges of the variable distance d1, the variable distance d2, and the variable distance d3 satisfy:

[0016] 9.585 mm ≤ d1 ≤ 71.931 mm,

[0017] 1.850 mm ≤ d2 ≤ 37.436 mm,

[0018] 12.923 mm ≤ d3 ≤ 75.285 mm.

[0019] Further, the third positive meniscus lens is spaced 27.869 mm from the second intermediate image plane, the third positive meniscus lens is spaced 1 mm from the fifth doublet lens, and the fifth doublet lens is spaced 1 mm from the fourth positive meniscus lens.

[0020] Advantages: Compared with the prior art, the present invention has the following remarkable advantages: Through the initial structural parameters of the two-component "positive-positive" optical power variable magnification component, the sight realizes continuous zooming from 1 to 12 times under a compact structure. After optimization, the cam curve of the variable magnification component is smooth and continuous, and the pressure angle of the cam curve is significantly reduced, with its value always less than 60°. In addition, the objective lens group, relay image rotation group, and eyepiece group of the sight are separated and independently designed and then connected and combined. After aberration compensation and pupil connection of each module system, various aberrations of the sight optical system can be effectively corrected, while reducing the fluctuation range of the exit pupil distance. Finally, the sight optical system has high-quality imaging quality at each magnification and full field of view. Using the design method of aberration compensation optimization effectively reduces the distortion, field curvature, and chromatic aberration of the sight system. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the present invention;

[0022] Figure 2 is a schematic diagram of 1-12 times continuous zooming of the present invention;

[0023] Figure 3 is a schematic diagram of the cam curve of the variable magnification component;

[0024] Figure 4 is a schematic diagram of the outer tube of the variable magnification cam;

[0025] Figure 5 is a spot diagram of the present invention at 1 time;

[0026] Figure 6 is a spot diagram of the present invention at 7 times;

[0027] Figure 7 is a spot diagram of the present invention at 12 times;

[0028] Figure 8 is a field curvature and distortion diagram of the present invention at 1 time, where (a) is the field curvature diagram and (b) is the distortion diagram;

[0029] Figure 9 is a field curvature and distortion diagram of the present invention at 7 times, where (a) is the field curvature diagram and (b) is the distortion diagram;

[0030] Figure 10This is the field curvature and distortion diagram of the present invention at 12 times magnification, where (a) is the field curvature diagram and (b) is the distortion diagram. Detailed implementation manner

[0031] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings.

[0032] As Figure 1 shown, the compact multi-fold continuous zoom aiming optical system of the present invention includes an objective lens group 1, a relay image rotation group 2, and an eyepiece group 3; the objective lens group 1 includes a first double convex lens 11, a second double convex lens 12, a first double concave lens 13, and a third double convex lens 14 arranged in sequence from the object side to the image side;

[0033] The relay image rotation group 2 includes a first positive meniscus lens 21, a fourth double convex lens 22, a first negative meniscus lens 23, a second negative meniscus lens 24, a fifth double convex lens 25, a second double concave lens 26, and a second positive meniscus lens 27 arranged in sequence from the object side to the image side;

[0034] The eyepiece group 3 includes a third positive meniscus lens 31, a third double concave lens 32, a sixth double convex lens 33, and a fourth positive meniscus lens 34 arranged in sequence from the object side to the image side.

[0035] A diaphragm is provided on the front surface of the first double convex lens 11.

[0036] The second double convex lens 12 and the first double concave lens 13 form a first doublet lens, the fourth double convex lens 22 and the first negative meniscus lens 23 form a second doublet lens, the second negative meniscus lens 24 and the fifth double convex lens 25 form a third doublet lens, the second double concave lens 26 and the second positive meniscus lens 27 form a fourth doublet lens, and the third double concave lens 32 and the sixth double convex lens 33 form a fifth doublet lens.

[0037] The image plane of the objective lens group 1 is the first intermediate image plane of the aiming optical system, located between the third double convex lens 14 and the first positive meniscus lens 21. The image plane of the relay image rotation group 2 is the second intermediate image plane of the aiming optical system, located between the fourth doublet lens and the third positive meniscus lens 31.

[0038] A reticle is provided at the second intermediate image plane, and the image-side focal plane of the reticle coincides with the second intermediate image plane of the aiming optical system.

[0039] The first double convex lens 11 is 0.5 mm away from the first doublet lens, the first doublet lens is 62.713 mm away from the third double convex lens 14, and the third double convex lens 14 is 9.728 mm away from the first intermediate image plane.

[0040] The first positive meniscus lens 21 is spaced 8.351 mm from the first intermediate image plane. The distance between the first positive meniscus lens 21 and the second doublet lens is a variable distance d1. The distance between the second doublet lens and the third doublet lens is a variable distance d2. The distance between the third doublet lens and the fourth doublet lens is a variable distance d3. The fourth doublet lens is spaced 13.942 mm from the second intermediate image plane.

[0041] The variation ranges of the variable distance d1, the variable distance d2, and the variable distance d3 satisfy:

[0042] 9.585 mm ≤ d1 ≤ 71.931 mm,

[0043] 1.850 mm ≤ d2 ≤ 37.436 mm,

[0044] 12.923 mm ≤ d3 ≤ 75.285 mm.

[0045] The third positive meniscus lens 31 is spaced 27.869 mm from the second intermediate image plane. The third positive meniscus lens 31 is spaced 1 mm from the fifth doublet lens. The fifth doublet lens is spaced 1 mm from the fourth positive meniscus lens 34.

[0046] Embodiment

[0047] The basic technical index parameters of the embodiment of the present invention are as follows:

[0048] Magnification: realizing continuous variable magnification from 1 to 12 times;

[0049] Field of view angle: 18° to 1.5°;

[0050] Objective lens aperture: 24 mm;

[0051] Working wavelength: 0.486 um to 0.656 um;

[0052] Exit pupil distance: 89.066 mm to 95.249 mm;

[0053] Exit pupil diameter: 2 mm to 4 mm;

[0054] Zoom range: 20 mm to 240 mm;

[0055] Total length of the telescopic sight structure: 266.306 mm (compact structure, total length ≤ 1.2 times the long focal length).

[0056] The specific parameters of each lens and the element intervals in the embodiment of the present invention are shown in Table 1 and Table 2:

[0057] Table 1: Specific parameters of each lens

[0058] Surface serial number Radius of curvature (mm) Thickness (mm) Nd Vd 1 (Diaphragm) Infinity 0 2 72.163 3 1.517 64.212 3 -407.081 0.5 4 51.684 3 1.517 64.212 5 -162.001 2 1.74 28.291 6 139.426 62.713 7 68.517 4 1.517 64.212 8 -49.180 9.728 9 (First image plane) Infinity 8.351 10 32.518 3 1.517 64.212 11 79.776 d1 12 944.225 3 1.639 55.472 13 -9.887 2 1.805 25.477 14 -17.416 d2 15 29.129 2 1.80 34.972 16 15.354 3 1.517 64.212 17 -34.875 d3 18 -9.068 1.5 1.517 64.212 19 24.151 2 1.74 28.291 20 77.963 13.941 21 (Second image plane) Infinity 27.869 22 -259.148 6 1.613 60.382 23 -36.554 1 24 -114.551 4 1.805 25.477 25 33.849 8 1.487 70.419 26 -50.429 1 27 42.591 7 1.80 34.972 28 364.838 89.066-95.249

[0059] Table 2: Component Spacing

[0060]

[0061] For the compact multi - fold continuous zoom aiming optical system of the present invention, the second cemented lens and the third cemented lens in the relay image - rotating group 2 are axially moved according to a certain rule to achieve the continuous zoom function. The second cemented lens and the third cemented lens are respectively called the zoom group and the compensation group, and the two are collectively called the zoom assembly. As Figure 2 shown, after the zoom group and the compensation group are axially moved by a specific distance, the aiming scope obtains different magnification factors. At this time, the system has corresponding variable spacings d1, d2, d3, and the variable spacing values at specific magnification factors are shown in Table 2.

[0062] Mechanically, the movement of the zoom group and the compensation group relies on the curve grooves on the cylindrical cam tube to achieve coordinated movement. The cylindrical cam tube is a hollow cylinder, with two precision curve grooves machined on its surface, corresponding to the movement paths of the zoom group and the compensation group respectively. When the cam tube rotates, the guide pins (or rollers) embedded in the curve grooves will move along the track of the grooves. The guide pins are connected to the zoom assembly, thereby converting the rotational movement into the axial displacement of the lens group to achieve the continuous zoom function.

[0063] In the embodiment of the present invention, the outer diameter of the cam outer tube is 30 mm. As Figure 3 shown, it is the schematic diagram of the cam curve of the zoom assembly in the embodiment of the present invention. It can be seen from this figure that the total cam rotation angle required for the cam curve to zoom from 1 to 12 times is 243.23°. The zoom group and the compensation group share a set of cam rotation angle data, and both the zoom group and the compensation group perform non - linear movements. During the zoom movement, the zoom group continuously moves unidirectionally towards the object side, while the compensation group shows a reciprocating movement characteristic of first moving towards the image side and then turning towards the object side. The working spacing between the two components shows a non - linear change trend of first increasing and then decreasing. Further calculation of the cam curve data shows that the pressure - angle of both cam curves is less than 60°. At the same time, the overall curve is smooth and fluent during the zoom process, meeting the requirements of industrial manufacturing.

[0064] Convert Figure 3 the cam rotation angle data in Figure 4 into the vertical - axial displacement data, and use Solidworks software to fit the cam curve and wrap it on the cylindrical cam outer tube, which can present the actual effect diagram of the zoom cam outer tube as shown in

[0065] As Figure 5 shown, it is the spot diagram of the aiming scope system at different fields of view when the magnification factor is 1 time in the embodiment. It can be seen from the figure that the maximum rms (root - mean - square) radius is 14.094 um, and the maximum GEO (geometric) radius is 49.408 um; as Figure 6The spot diagram of the telescopic sight system of the embodiment at a magnification of 7 times in different fields of view is shown. It can be seen from the figure that the maximum rms (root mean square) radius is 14.848um, and the maximum GEO (geometric) radius is 41.861um; as Figure 7 The spot diagram of the telescopic sight system of the embodiment at a magnification of 12 times in different fields of view is shown. It can be seen from the figure that the maximum rms (root mean square) radius is 28.228um, and the maximum GEO (geometric) radius is 74.403um, and the imaging quality is good.

[0066] The objective lens group 1, relay image inversion group 2, and eyepiece group 3 of the telescopic sight are initially designed separately and independently. The objective lens group 1 and the relay image inversion group 2 are connected to form a zoom objective lens group. At this time, the aberration values of the zoom objective lens group and the eyepiece group 3 are observed and analyzed, and aberration compensation optimization design is adopted for these two components respectively to reduce the final aberration of the telescopic sight system after final coupling.

[0067] As Figure 8 The field curvature and distortion diagram of the telescopic sight optical system of the embodiment of the present invention at 1 time is shown: It can be seen from the figure that the maximum field curvature of the system is 0.6mm, and the maximum distortion is 0.25%; as Figure 9 The field curvature and distortion diagram of the telescopic sight optical system of the embodiment of the present invention at 7 times is shown: It can be seen from the figure that the maximum field curvature of the system is 0.25mm, and the maximum distortion is 0.6%; as Figure 10 The field curvature and distortion diagram of the telescopic sight optical system of the embodiment of the present invention at 12 times is shown: It can be seen from the figure that the maximum field curvature of the system is 0.7mm, and the maximum distortion is 0.8%. The field curvature and distortion are both small, meeting the use requirements.

[0068] The chromatic aberration magnification effect of the telescopic sight system is significant at high magnifications. It is necessary to balance the aberration throughout the zoom range, and the chromatic aberration is preferentially optimized at high magnifications. The system comprehensively corrects the lateral aberration at each magnification within the wide spectral range of 0.486~0.656μm and the zoom range, and focuses on suppressing the lateral chromatic aberration under high magnification conditions, so as to ensure the overall excellent performance of the imaging quality within the extended magnification range.

[0069] In addition, when optimizing the zoom objective lens group, the stability of the exit pupil distance of the system at each magnification can be optimized by using the optimization operand, which can reduce the fluctuation range of the exit pupil distance of the telescopic sight system. The maximum fluctuation of the exit pupil distance of the telescopic sight system is 6.183mm.

[0070] In summary, based on the Gaussian zoom theory of the two-component "positive-positive" optical power zoom component, the present invention reasonably matches the system structure parameters and the optical characteristics of the lens, and adopts aberration compensation and optimization design. On the basis of realizing a compact structure, it successfully achieves a wide-range continuous zoom of 1 to 12 times. It solves the problems of large fluctuation range of exit pupil distance and too large pressure angle of the cam curve existing in the traditional sighting system, and significantly improves the system stability. After optimization, the key aberrations of the sighting system are effectively controlled, meeting the high-quality imaging requirements of the high-zoom ratio sighting system.

Claims

1. A compact multi-stage continuous zoom aiming scope optical system, characterized in that, It includes an objective lens group (1), a relay image conversion group (2), and an eyepiece group (3); the objective lens group (1) includes a first double convex lens (11), a second double convex lens (12), a first double concave lens (13), and a third double convex lens (14) arranged in sequence from the object side to the image side; the relay image conversion group (2) includes a first positive meniscus lens (21), a fourth double convex lens (22), a first negative meniscus lens (23), a second negative meniscus lens (24), a fifth double convex lens (25), a second double concave lens (26), and a second positive meniscus lens (27) arranged in sequence from the object side to the image side; the eyepiece group (3) includes a third positive meniscus lens (31), a third double concave lens (32), a sixth double convex lens (33), and a fourth positive meniscus lens (34) arranged in sequence from the object side to the image side.

2. The compact multi-stage continuous zoom aiming scope optical system according to claim 1, characterized in that, A diaphragm is provided on the front surface of the first double convex lens (11).

3. The compact multi-stage continuous zoom aiming optical system according to claim 1, characterized in that The second double convex lens (12) and the first double concave lens (13) form a first double cemented lens, the fourth double convex lens (22) and the first negative meniscus lens (23) form a second double cemented lens, the second negative meniscus lens (24) and the fifth double convex lens (25) form a third double cemented lens, the second double concave lens (26) and the second positive meniscus lens (27) form a fourth double cemented lens, and the third double concave lens (32) and the sixth double convex lens (33) form a fifth double cemented lens.

4. The compact multi-stage continuous zoom telescopic sight optical system according to claim 1, characterized in that, The image plane of the objective lens group (1) is the first intermediate image plane of the telescopic sight system, and is located between the third double convex lens (14) and the first positive meniscus lens (21).

5. The compact multi-stage continuous zoom aiming optical system according to claim 1, characterized in that, The image plane of the relay image conversion group (2) is the second intermediate image plane of the telescopic sight system, and is located between the fourth double cemented lens and the third positive meniscus lens (31).

6. The compact multi-stage continuous zoom aiming optical system according to claim 5, characterized in that, A reticle is provided at the second intermediate image plane, and the image-side focal plane of the reticle coincides with the second intermediate image plane of the telescopic sight system.

7. The compact multi-stage continuous zoom aiming optical system according to claim 1, characterized in that, The distance between the first double convex lens (11) and the first double cemented lens is 0.5 mm, the distance between the first double cemented lens and the third double convex lens (14) is 62.713 mm, and the distance between the third double convex lens (14) and the first intermediate image plane is 9.728 mm.

8. The compact multi-stage continuous zoom aiming optical system according to claim 1, characterized in that, The distance between the first positive meniscus lens (21) and the first intermediate image plane is 8.351 mm, the distance between the first positive meniscus lens (21) and the second double cemented lens is a variable distance d1, the distance between the second double cemented lens and the third double cemented lens is a variable distance d2, the distance between the third double cemented lens and the fourth double cemented lens is a variable distance d3, and the distance between the fourth double cemented lens and the second intermediate image plane is 13.942 mm.

9. The compact multi-stage continuous zoom aiming optical system according to claim 8, characterized in that, The variation ranges of the variable distance d1, the variable distance d2, and the variable distance d3 satisfy: 9.585 mm ≤ d1 ≤ 71.931 mm, 1.850 mm ≤ d2 ≤ 37.436 mm, 12.923 mm ≤ d3 ≤ 75.285 mm.

10. The compact multi-fold continuous zoom aiming scope optical system according to claim 1, wherein The distance between the third positive meniscus lens (31) and the second intermediate image plane is 27.869 mm, the distance between the third positive meniscus lens (31) and the fifth double cemented lens is 1 mm, and the distance between the fifth double cemented lens and the fourth positive meniscus lens (34) is 1 mm.

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