A aiming lens with a large zoom ratio and continuous zoom

Abstract

A large zoom ratio continuous zoom sighting lens, comprising: an objective lens group A, the objective lens group A comprising a biconvex lens A-1, a biconvex lens A-2, a biconcave lens A-3, a biconvex lens A-4, and a biconcave lens A-5; a relay lens group B, arranged between the objective lens group A and the image side, the relay lens group B comprising a front fixed group B1, a first movable group B2, a second movable group B3, and a rear fixed group B4, the front fixed group B1 being a positive meniscus lens B1-1, the first movable group B2 comprising a plurality of lenses arranged in sequence from the object side to the image side. The eyepiece C comprises a negative meniscus lens C-1, a positive meniscus lens C-2, a positive meniscus lens C-3 and a biconvex lens C-4; the diaphragm is arranged on the objective lens A-1 and coincides with the surface of the objective lens A-1.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging, in particular to an aiming lens with large variable magnification ratio and continuous zoom. Background Art

[0002] Large magnification ratio and large field of view have always been the technical performance pursued by continuous zoom scopes, but in terms of civilian scopes, the current continuous zoom products mostly have a magnification ratio of 3x and 4x and a small field of view. With the updating of firearms and the improvement of machining capabilities, consumers are more eager to have scopes with higher magnification ratios and larger fields of view.

[0003] In terms of high-zoom scopes, Germany's Zeiss company, U.S. Patent No. US2007 / 0019289A1, European Patent EP1746451 (A2), etc. have successively proposed a 6x zoom ratio zoom image transfer system, which has greatly improved the performance of civilian scopes. In pursuit of higher zoom ratios, some designers have abandoned the traditional "positive-positive" optical power structure and used more complex structures as zoom steering systems. For example, Chinese patent CN101713621A uses a "positive-negative" optical power lens group for zoom image rotation, Chinese patent CN101609204B uses a "positive-negative-positive" three-lens group for zoom image rotation, and Chinese patent CN106908941A uses a "negative-positive-negative" three-lens group for zoom image rotation. For example, the American REDFIELD company uses a "positive-positive-negative" three-lens group as a zoom image rotation system to develop a 5x zoom ratio riflescope series. These structures can achieve 5x, 6x, 8x and even have the potential to reach higher zoom ratios.

[0004] Due to the large zoom ratio, designers struggle to balance performance at all magnifications. This often results in excessively wide variations in pupil distance or severe distortion at a given magnification. These issues are particularly pronounced in complex zoom structures. High-zoom scopes also suffer from the problem of the cam curve having an excessively small axial inclination angle, which can cause the cam to become stuck or even jammed during zooming. Due to these issues, only a few companies currently offer high-zoom scopes that meet the requirements. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a sighting lens with large zoom ratio and continuous zoom, which not only realizes the functions of large zoom ratio, large field of view and continuous zoom of the sighting lens, but also solves the problems that the cam curve of the large zoom ratio zoom lens is not smooth enough during the zooming process, and the pupil distance variation range of the long pupil distance gun sight is too large.

[0006] To solve the above technical problems, an embodiment of the present invention provides a sighting lens with a large zoom ratio and continuous zoom, comprising:

[0007] An objective lens assembly A, comprising a biconvex lens A-1, a biconvex lens A-2, a biconcave lens A-3, a biconvex lens A-4, and a biconcave lens A-5, arranged in order from the object side to the image side;

[0008] a relay lens group B disposed between the objective lens group A and the image side, the relay lens group B comprising a front fixed group B1, a first movable group B2, a second movable group B3, and a rear fixed group B4, arranged in sequence from the object side to the image side; the front fixed group B1 comprising a positive meniscus lens B1-1; the first movable group B2 comprising a biconvex lens B2-1, a biconcave lens B2-2, and a positive meniscus lens B2-3, arranged in sequence from the object side to the image side; the second movable group B3 comprising a positive meniscus lens B3-1, a biconvex lens B3-2, and a positive meniscus lens B3-3, arranged in sequence from the object side to the image side; and the rear fixed group B4 comprising a biconvex lens B4-1 and a biconcave lens B4-2, arranged in sequence from the object side to the image side;

[0009] Eyepiece C, comprising a negative meniscus lens C-1, a positive meniscus lens C-2, a positive meniscus lens C-3, and a biconvex lens C-4, arranged in order from the object side to the image side;

[0010] an aperture, provided on the objective lens A-1 and coinciding with the surface of the objective lens A-1;

[0011] The image-side focal plane of the objective lens A is the first image plane, which is arranged between the objective lens A and the relay lens group B;

[0012] The object focal plane of the eyepiece C is the second image plane, which is arranged between the relay lens group B and the eyepiece C; the positions of the first image plane and the second image plane remain unchanged during the zoom process;

[0013] The focal lengths of the objective lens A and the eyepiece C satisfy: 1.286 ≥ F0 / Fe,

[0014] Where F0 is the focal length of the objective lens group, and Fe is the focal length of the eyepiece group.

[0015] The biconvex lens A-2 and the biconcave lens A-3 are closely bonded to form a first cemented group.

[0016] The positive meniscus lens B3-1 and the biconvex lens B3-2 are closely bonded to form a second cemented group.

[0017] The biconvex lens B4-1 and the biconcave lens B4-2 are closely bonded to form a third cemented group.

[0018] The negative meniscus lens C-1 and the positive meniscus lens C-2 are closely bonded to form a fourth cemented group.

[0019] The air gap between the biconvex lens A-1 and the first cemented group is 0.5 mm, the air gap between the first cemented group and the biconvex lens A-4 is 25.261 mm, the air gap between the biconvex lens A-4 and the biconcave lens A-5 is 4.001 mm, and the air gap between the biconcave lens A-5 and the first image plane is 10 mm.

[0020] The air gap between the first image plane and the positive meniscus lens B1-1 is 10.757 mm, the air gap between the biconvex lens B2-1 and the biconcave lens B2-2 is 2.000 mm, the air gap between the biconcave lens B2-2 and the positive meniscus lens B2-3 is 2.000 mm, the air gap between the second cemented group and the positive meniscus lens B3-3 is 1.000 mm, and the air gap between the third cemented group and the second image plane is 17.838 mm.

[0021] The air gap between the second image plane and the fourth cemented group is 10.000 mm, the air gap between the fourth cemented group and the positive meniscus lens C-3 is 0.300 mm, and the air gap between the positive meniscus lens C-3 and the biconvex lens C-4 is 0.3000 mm.

[0022] When the lens moves from the wide-angle end to the aiming end, the first moving group B2 moves toward the objective lens first and then moves away from the objective lens, and the second moving group B3 always moves toward the objective lens.

[0023] The distance between the positive meniscus lens B1-1 of the front fixed group B1 and the biconvex lens B2-1 of the first movable group B2 is variable and ranges from 2.830 mm to 81.223 mm.

[0024] The positive meniscus lens B2-3 of the first moving group B2 and the positive meniscus lens B3-1 of the second moving group B3 have a variable spacing ranging from 4.000 mm to 48.087 mm;

[0025] The distance between the positive meniscus lens B3-3 of the second movable group B3 and the biconvex lens B4-1 of the rear fixed group B4 is variable and ranges from 6.899 mm to 96.049 mm.

[0026] The beneficial effects of the above technical solution of the present invention are as follows:

[0027] In the present invention, the first moving group and the second moving group are both positive optical power lens groups. By selecting specific initial parameters to solve the magnification curve, the "positive-positive" optical power magnification structure can achieve continuous magnification with a magnification ratio of 10 times and at the same time have a high vertical axis magnification ratio. When achieving continuous magnification of 1 to 10 times, the high magnification ratio of the relay lens group allows the objective lens group to select a relatively small focal length, thereby making the height of the first image plane lower under the same field of view, so that the height of the first image plane meets the assembly requirements when the system has a field of view angle of 23 degrees. At the same time, the "positive-positive" optical power magnification structure makes the overall structure of the aiming lens compact, the cam curve smooth, the exit pupil distance long and the exit pupil distance variation range small. The reasonable distribution of optical power enables the lens to have high image quality at all magnifications and fields of view. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the optical structure of the aiming lens with large variable magnification and continuous zoom of the present invention;

[0029] Figure 2 This is a schematic diagram of the continuous zoom of the aiming lens with a large zoom ratio of 1 to 10 times of the present invention;

[0030] Figure 3 Schematic diagram of the structure of the zoom tube in an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the curved motion on the zoom barrel in an embodiment of the present invention;

[0032] Figure 5 This is a rendering of a cam tube according to an embodiment of the present invention;

[0033] Figure 6 is the MTF curve of the zoom objective lens at 1x in an embodiment of the present invention;

[0034] Figure 7 : is the MTF curve of the zoom objective lens at 4 times of the embodiment of the present invention;

[0035] Figure 8 : is the MTF curve of the zoom objective lens at 7 times according to an embodiment of the present invention;

[0036] Figure 9 : is the MTF curve of the zoom objective lens at 10 times of the embodiment of the present invention;

[0037] Figure 10 1 is the field curvature and distortion curve of the eyepiece according to the embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0039] like Figure 1As shown, an embodiment of the present invention provides a sighting lens with a large zoom ratio and continuous zoom, comprising:

[0040] An objective lens assembly A, comprising a biconvex lens A-1, a biconvex lens A-2, a biconcave lens A-3, a biconvex lens A-4, and a biconcave lens A-5, arranged in order from the object side to the image side;

[0041] a relay lens group B disposed between the objective lens group A and the image side, the relay lens group B comprising a front fixed group B1, a first movable group B2, a second movable group B3, and a rear fixed group B4 arranged in sequence from the object side to the image side; the front fixed group B1 comprising a positive meniscus lens B1-1; the first movable group B2 comprising a biconvex lens B2-1, a biconcave lens B2-2, and a positive meniscus lens B2-3 arranged in sequence along a light beam from the object side to the image side; the second movable group B3 comprising a positive meniscus lens B3-1, a biconvex lens B3-2, and a positive meniscus lens B3-3 arranged in sequence from the object side to the image side; and the rear fixed group B4 comprising a biconvex lens B4-1 and a biconcave lens B4-2 arranged in sequence from the object side to the image side;

[0042] Eyepiece C, comprising a negative meniscus lens C-1, a positive meniscus lens C-2, a positive meniscus lens C-3, and a biconvex lens C-4, arranged in order from the object side to the image side;

[0043] an aperture, provided on the objective lens A-1 and coinciding with the surface of the objective lens A-1;

[0044] The image-side focal plane of the objective lens A is the first image plane, which is arranged between the objective lens A and the relay lens group B;

[0045] The object focal plane of the eyepiece C is the second image plane, which is arranged between the relay lens group B and the eyepiece C. During the zoom process, the positions of the first image plane and the second image plane remain unchanged.

[0046] The focal lengths of the objective lens A and the eyepiece C satisfy: 1.286 ≥ F0 / Fe,

[0047] Where F0 is the focal length of the objective lens group, and Fe is the focal length of the eyepiece group.

[0048] The biconvex lens A-2 and the biconcave lens A-3 are closely bonded to form a first cemented group.

[0049] The positive meniscus lens B3-1 and the biconvex lens B3-2 are closely bonded to form a second cemented group.

[0050] The biconvex lens B4-1 and the biconcave lens B4-2 are closely bonded to form a third cemented group.

[0051] The negative meniscus lens C-1 and the positive meniscus lens C-2 are closely bonded to form a fourth cemented group.

[0052] The air gap between the biconvex lens A-1 and the first cemented group is 0.5 mm, the air gap between the first cemented group and the biconvex lens A-4 is 25.261 mm, the air gap between the biconvex lens A-4 and the biconcave lens A-5 is 4.001 mm, and the air gap between the biconcave lens A-5 and the first image plane is 10 mm.

[0053] The air gap between the first image plane and the positive meniscus lens B1-1 is 10.757 mm, the air gap between the biconvex lens B2-1 and the biconcave lens B2-2 is 2.000 mm, the air gap between the biconcave lens B2-2 and the positive meniscus lens B2-3 is 2.000 mm, the air gap between the second cemented group and the positive meniscus lens B3-3 is 1.000 mm, and the air gap between the third cemented group and the second image plane is 17.838 mm.

[0054] The air gap between the second image plane and the fourth cemented group is 10.000 mm, the air gap between the fourth cemented group and the positive meniscus lens C-3 is 0.300 mm, and the air gap between the positive meniscus lens C-3 and the biconvex lens C-4 is 0.3000 mm.

[0055] When the lens moves from the wide-angle end to the aiming end, the moving direction of the first moving group B2 is toward the objective lens, and the moving direction of the first moving group B2 is toward the first moving group B2.

[0056] There is a variable distance D1 between the positive meniscus lens B1-1 of the front fixed group B1 and the biconvex lens B2-1 of the first movable group B2, and the range of D1 is 2.830mm to 81.223mm;

[0057] There is a variable distance D2 between the positive meniscus lens B2-3 of the first moving group B2 and the positive meniscus lens B3-1 of the second moving group B3, and the range of D2 is 4.000mm to 48.087mm;

[0058] There is a variable distance D3 between the positive meniscus lens B3-3 of the second movable group B3 and the biconvex lens B4-1 of the rear fixed group B4, and the range of D3 is 6.899mm to 96.049mm.

[0059] The above-mentioned large zoom ratio continuous zoom sighting lens can obtain a large zoom ratio continuous zoom steering group, which includes a zoom barrel with a zoom curve groove and two lens groups arranged on the zoom barrel and moving along the curve groove, such as Figure 3As shown, the zoom curved groove includes a first curved groove near the objective lens group and a second curved groove near the eyepiece. The first curved groove extends downward from the upper end along the first direction in the axial direction of the zoom barrel, and the second curved groove extends from the upper end to the middle along the second direction in the axial direction of the zoom barrel. The planar unfolded shape of the first curved groove consists of a straight line segment at the low magnification end and a curved segment at the high magnification end, and the planar unfolded shape of the second curved groove consists of a curved segment at the low magnification end and a straight line segment at the high magnification end, and the transition between the straight line segment and the curved segment is smooth. The starting ends of the first and second curved grooves are on a straight line parallel to the axial direction of the zoom barrel, and the ends of the first and second curved grooves are on another straight line parallel to the axial direction of the zoom barrel.

[0060] The two lens groups correspond to the first moving group and the second moving group in the sighting lens with large zoom ratio and continuous zoom, respectively, and the first moving group and the second moving group are both positive power lens groups. The first moving group is set in the first curved groove, and the second moving group is set in the second curved groove. Figure 2 and Figure 4 As shown, Figure 4 The left curve is the motion curve of the first moving group in the first curve groove, and the right curve is the motion curve of the second moving group in the second curve groove. When the lens moves from the wide-angle end to the aiming end, as the magnification increases, the movement direction of the first moving group B2 is first toward the objective lens and then toward the Away from the objective lens The second moving group B3 moves in the direction of the objective lens.

[0061] The first moving group and the second moving group move to achieve continuous magnification of 1 to 10 times. Since the first moving group and the second moving group are both positive optical focal length lens groups, the "positive-positive" optical focal length magnification structure is able to achieve continuous magnification of a magnification ratio of 10 times by selecting specific initial parameters to solve the magnification curve. In addition, the "positive-positive" optical focal length magnification structure makes the overall structure of the aiming lens compact, the cam curve smooth, the exit pupil distance long, and the exit pupil distance change range small.

[0062] The physical parameters of each lens in this embodiment meet the data requirements shown in Table 1:

[0063] Table 1

[0064]

[0065]

[0066] When the scope is at 1x, 4x, 7x and 10x, the values of the variable distances D1, D2 and D3 are shown in Table 2:

[0067] Table 2

[0068]

[0069] In the embodiment of the present invention, the sight composed of the above lens assembly achieves the following optical indicators:

[0070] (1) Magnification: 1 to 10 times continuous magnification, the magnification ratio is 10 times;

[0071] (2) Field of view: 23° to 2.3°;

[0072] (3) Objective lens aperture: 24 mm;

[0073] (4) Exit pupil diameter: 2.4 mm to 8 mm;

[0074] (5) Exit pupil distance: 108.4mm to 97.432mm;

[0075] (6) Working wavelength: 0.486μm~0.656μm visible light band;

[0076] (7)Total system length: 269.505mm.

[0077] The zoom tube structure of the embodiment of the present invention is shown in FIG. Figure 5 As shown: The diameter of the zoom tube in the figure is 27mm, and it can achieve continuous magnification of 1 to 10 times by rotating 250°. The zoom tube is smooth and the maximum rise angle is 67.52°.

[0078] The exit pupil diameter is set to 2.4mm for image quality evaluation. The MTF curves of the zoom objective lens composed of the objective lens and the relay system at 1x, 4x, 7x, and 10x are shown in Figure 2. Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 As shown in the figure, it can be seen that at the spatial frequency of 40lp / mm, the MTF of the zoom objective lens 0.7 corresponding to the system 1x, 4x, 7x, and 10x is better than 0.2.

[0079] The eyepiece image quality is evaluated with the pupil distance set to 100mm. The field curvature and distortion curves of the eyepiece are shown in Figure 10 shown by Figure 10 It can be seen that when the exit pupil distance is 100mm, the field curvature of the eyepiece is less than 0.3 and the percentage distortion is less than 5%.

[0080] The aiming lens of the present invention solves the zoom curve by selecting specific initial parameters, so that the "positive-positive" optical focal length zoom structure can achieve continuous zooming with a zoom ratio of 10 times and simultaneously have a high vertical axis magnification. When achieving continuous zooming of 1 to 10 times, the high magnification of the relay lens group enables the objective lens group to select a relatively small focal length, thereby making the height of the first image plane lower under the same field of view, so that the height of the first image plane meets the assembly requirements when the system has a field of view angle of 23 degrees.

[0081] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A sighting lens with a large variable magnification ratio and continuous zoom, characterized in that: include: An objective lens assembly A, comprising a biconvex lens A-1, a biconvex lens A-2, a biconcave lens A-3, a biconvex lens A-4, and a biconcave lens A-5, arranged in order from the object side to the image side; a relay lens group B disposed between the objective lens group A and the image side, the relay lens group B comprising a front fixed group B1, a first movable group B2, a second movable group B3, and a rear fixed group B4, arranged in sequence from the object side to the image side; the front fixed group B1 comprising a positive meniscus lens B1-1; the first movable group B2 comprising a biconvex lens B2-1, a biconcave lens B2-2, and a positive meniscus lens B2-3, arranged in sequence from the object side to the image side; the second movable group B3 comprising a positive meniscus lens B3-1, a biconvex lens B3-2, and a positive meniscus lens B3-3, arranged in sequence from the object side to the image side; and the rear fixed group B4 comprising a biconvex lens B4-1 and a biconcave lens B4-2, arranged in sequence from the object side to the image side; Eyepiece C, comprising a negative meniscus lens C-1, a positive meniscus lens C-2, a positive meniscus lens C-3, and a biconvex lens C-4, arranged in order from the object side to the image side; an aperture, provided on the objective lens A-1 and coinciding with the surface of the objective lens A-1; The image-side focal plane of the objective lens A is the first image plane, which is arranged between the objective lens A and the relay lens group B; The object focal plane of the eyepiece C is the second image plane, which is arranged between the relay lens group B and the eyepiece C; the positions of the first image plane and the second image plane remain unchanged during the zoom process; The focal lengths of the objective lens A and the eyepiece C satisfy: 1.286 ≥ F0 / Fe, Where F0 is the focal length of the objective lens group, and Fe is the focal length of the eyepiece group; It also includes a zoom barrel having a zoom curved groove, the zoom curved groove including a first curved groove near the objective lens group and a second curved groove near the eyepiece, the first curved groove extending downward from the upper end along a first direction in the axial direction of the zoom barrel, and the second curved groove extending from the upper end to the middle along a second direction in the axial direction of the zoom barrel, the planar unfolded shape of the first curved groove consisting of a straight line segment at the low magnification end and a curved segment at the high magnification end, and the planar unfolded shape of the second curved groove consisting of a curved segment at the low magnification end and a straight line segment at the high magnification end, and the transition between the straight line segment and the curved segment is smooth; the starting ends of the first curved groove and the second curved groove are on a straight line parallel to the axial direction of the zoom barrel, and the ending ends of the first curved groove and the second curved groove are on another straight line parallel to the axial direction of the zoom barrel; The two lens groups correspond respectively to the first moving group and the second moving group in the aiming lens with large zoom ratio and continuous zoom, and the first moving group and the second moving group are both positive optical focal length lens groups. The first moving group is set in the first curved groove, and the second moving group is set in the second curved groove.

2. The large-magnification continuous zoom sighting lens according to claim 1, characterized in that: The biconvex lens A-2 and the biconcave lens A-3 are closely bonded to form a first cemented group; The positive meniscus lens B3-1 and the biconvex lens B3-2 are closely bonded to form a second cemented group; The biconvex lens B4-1 and the biconcave lens B4-2 are closely bonded to form a third cemented group; The negative meniscus lens C-1 and the positive meniscus lens C-2 are closely bonded to form a fourth cemented group; The air gap between the biconvex lens A-1 and the first cemented group is 0.5 mm, the air gap between the first cemented group and the biconvex lens A-4 is 25.261 mm, the air gap between the biconvex lens A-4 and the biconcave lens A-5 is 4.001 mm, and the air gap between the biconcave lens A-5 and the first image plane is 10 mm. The air gap between the first image plane and the positive meniscus lens B1-1 is 10.757 mm, the air gap between the biconvex lens B2-1 and the biconcave lens B2-2 is 2.000 mm, the air gap between the biconcave lens B2-2 and the positive meniscus lens B2-3 is 2.000 mm, the air gap between the second cemented group and the positive meniscus lens B3-3 is 1.000 mm, and the air gap between the third cemented group and the second image plane is 17.838 mm. The air gap between the second image plane and the fourth cemented group is 10.000 mm, the air gap between the fourth cemented group and the positive meniscus lens C-3 is 0.300 mm, and the air gap between the positive meniscus lens C-3 and the biconvex lens C-4 is 0.3000 mm.

3. The large-magnification continuous zoom sighting lens according to claim 1, characterized in that: When the lens moves from the wide-angle end to the aiming end, the first moving group B2 moves toward the objective lens first and then moves away from the objective lens, and the second moving group B3 always moves toward the objective lens.

4. The large-magnification continuous zoom sighting lens according to claim 3, characterized in that: The distance between the positive meniscus lens B1-1 of the front fixed group B1 and the biconvex lens B2-1 of the first movable group B2 is variable and ranges from 2.830 mm to 81.223 mm; The positive meniscus lens B2-3 of the first moving group B2 and the positive meniscus lens B3-1 of the second moving group B3 have a variable spacing range of 4.000 mm to 48.087 mm; The distance between the positive meniscus lens B3-3 of the second movable group B3 and the biconvex lens B4-1 of the rear fixed group B4 is variable and ranges from 6.899 mm to 96.049 mm.

Images