Long-focus gun sight lens

Abstract

The utility model belongs to the technical field of optical lenses, and particularly relates to a long-focus gun sight lens. The utility model relates to an imaging lens, which is composed of nine lenses and comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8 and a ninth lens L9 which are sequentially arranged from an object side to an image side, and the third lens L3 and the fourth lens L4 are glued to form a first glued lens group. The fifth lens L5 and the sixth lens L6 are glued to form a second glued lens group, and the seventh lens L7 and the eighth lens L8 are glued to form a third glued lens group. According to the utility model, a plurality of all-glass spherical lenses are adopted, various aberrations are corrected by reasonably distributing focal power and arranging the lenses, and the edge image quality is improved, so that the imaging quality is improved; and the maximum aperture can reach FNO.2.0, so that the lens can be used for imaging clearly under weak light, and the visual field is wider.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical lenses, and in particular relates to a long-focal-length gun-aiming lens. Background Art

[0002] In recent years, the development of surveillance camera technology along with the security trend has brought new changes to the networking of cameras, and the demand for industrial lenses has also continued to increase. Uncooled detectors have the advantages of low cost, small size, and low power consumption, and are widely used in security monitoring, individual weapons, and vehicle-mounted assisted driving instruments.

[0003] The current market demand is large and the prospects are broad. However, in many places, the environment is relatively poor and the brightness is low, so the clarity of the images captured by the camera is poor and the images are not sharp enough. Therefore, in order to further expand the market and meet the needs of low-cost solutions, it is necessary to design an economical long-focal-length rifle-scope lens with clear imaging and high reliability. Utility Model Content

[0004] The purpose of the utility model is to solve the problem that the clarity of the captured picture is poor and the picture is not sharp enough when the light brightness is low, and to provide a long-focal-length rifle aiming lens with the superior performance of infrared confocal (visible light and 850nm-940nm), which can effectively improve the light transmission efficiency, and has clear imaging, small size and wide application range.

[0005] In order to achieve the above purpose, the technical solution provided by the utility model is:

[0006] A long focal length rifle aiming lens, composed of nine lenses, including a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9, which are arranged in sequence from the object side to the image side, wherein:

[0007] The first lens L1 is a convex-concave glass spherical lens with positive power;

[0008] The second lens L2 is a convex-concave glass spherical lens with positive power;

[0009] The third lens L3 is a biconvex glass spherical lens with positive power;

[0010] The fourth lens L4 is a biconcave glass spherical lens with negative optical power;

[0011] The fifth lens L5 is a convex-concave glass spherical lens with negative optical power;

[0012] The sixth lens L6 is a convex-concave glass spherical lens with positive refractive power;

[0013] The seventh lens L7 is a meniscus glass spherical lens with positive refractive power;

[0014] The eighth lens L8 is a biconcave glass spherical lens with negative optical power;

[0015] The ninth lens L9 is a biconvex glass spherical lens with positive refractive power;

[0016] The third lens L3 and the fourth lens L4 are cemented together to form a first cemented lens group, the fifth lens L5 and the sixth lens L6 are cemented together to form a second cemented lens group, and the seventh lens L7 and the eighth lens L8 are cemented together to form a third cemented lens group, and the following conditions are met:

[0017]

[0018]

[0019] Among them, f1, f2, f3, f4, f5, f6, f7, f8, f9 are the focal lengths of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 respectively, f is the effective focal length of the lens, D is the entrance pupil diameter, and the units are all in mm.

[0020] Further, the focal lengths of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are 103.5±5%, 45.4±5%, 30.5±5%, -25.9±5%, -14.1±5%, 17.1±5%, 14.3±5%, -7.4±5% and 28.1±5% respectively, and the refractive indices are 1.95±0.1, 1.50±0.1, 1.59±0.1, 1.85±0.1, 1.85±0.1, 1.59±0.1, 1.95±0.1 respectively. , 1.77±0.1 and 1.52±0.1, and the corresponding object side curvature radii are 56.4±5%, 21.6±5%, 23.2±5%, -74.9±5%, 35.4±5%, 8.8±5%, -166.7±5%, -12.9±5% and 17.8±5%, respectively; the corresponding image side curvature radii are 126.5±5%, 468.4±5%, -74.9±5%, 31.8±5%, 8.8±5%, 48.8±5%, -12.9±5%, 10.9±5% and -73.8±5%, respectively; “-” indicates the negative direction; the units of the lens focal length and curvature radius are both mm.

[0021] Further, the on-axis thicknesses of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are 3.6 mm, 7.8 mm, 5.6 mm, 1.3 mm, 1.2 mm, 7.2 mm, 3.9 mm, 1.3 mm, and 5.4 mm respectively, and the on-axis spacings are 1.5 mm, 0.2 mm, 0 mm, 0.4 mm, 0 mm, 1.7 mm, 0 mm, 7.1 mm respectively.

[0022] Further, the Abbe numbers corresponding to the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are 18.0, 81.6, 68.6, 30.1, 23.8, 68.6, 18.0, 49.6, and 64.2 in sequence.

[0023] Further, for the long focal length gunsight lens, the optical total length TTL and the semi-image height IH corresponding to the maximum field of view angle satisfy: 13.0 < TTL / IH < 13.1.

[0024] Further, for the long focal length gunsight lens, the effective focal length f of the lens and the semi-image height IH corresponding to the maximum field of view angle satisfy: 0.06 < IH / f < 0.08; the optical total length TTL of the long focal length gunsight lens and the effective focal length f of the lens satisfy: 0.9 < TTL / f < 1.0.

[0025] Further, the working band of the long focal length gunsight lens is confocal for visible light and infrared light of 850 nm to 940 nm.

[0026] Further, a protective glass CG is also provided on the image side of the ninth lens L9.

[0027] Further, the long focal length gunsight lens further includes a diaphragm STOP, and the diaphragm STOP is located between the eighth lens L8 and the ninth lens L9.

[0028] Compared with the prior art, the remarkable advantages of the present utility model are as follows: multiple all-glass spherical lenses are adopted, and by reasonably distributing the optical power and arranging the lenses, various aberrations are corrected, the edge image quality is improved, and thus the imaging quality is enhanced; in terms of aperture, the maximum can reach FNO.2.0 aperture, enabling the lens to clearly image even in low light, and at the same time, the lens focal length ratio is reasonably set so that the working performance of the lens is stable under the environmental conditions of -30°C to +70°C, and the effective focal length of the lens can reach 60 mm, with a wider and farther field of view. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of the long focal length gunsight lens of the present utility model;

[0030] Figure 2 This is the MTF diagram of the utility model at a normal temperature of 20°C;

[0031] Figure 3 This is the MTF diagram of the utility model in a low temperature environment of -30°C;

[0032] Figure 4 This is the MTF diagram of the utility model in a high temperature environment of 70°C;

[0033] Figure 5 This is the MTF diagram of the utility model under the light source wavelength environment of 850nm;

[0034] Figure 6 This is the MTF diagram of the utility model under the environment of 940nm wavelength of light source. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0036] like Figure 1 As shown, a long focal length rifle aiming lens adopts 9 lenses, including a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9, which are arranged in sequence from the object side to the image side, wherein:

[0037] The first lens L1 is a convex-concave glass spherical lens with positive power;

[0038] The second lens L2 is a convex-concave glass spherical lens with positive refractive power;

[0039] The third lens L3 is a biconvex glass spherical lens with positive power;

[0040] The fourth lens L4 is a biconcave glass spherical lens with negative optical power;

[0041] The fifth lens L5 is a convex-concave glass spherical lens with negative optical power;

[0042] The sixth lens L6 is a convex-concave glass spherical lens with positive refractive power;

[0043] The seventh lens L7 is a meniscus glass spherical lens with positive refractive power;

[0044] The eighth lens L8 is a biconcave glass spherical lens with negative optical power;

[0045] The ninth lens L9 is a biconvex glass spherical lens with positive power;

[0046] The third lens L3 and the fourth lens L4 are cemented to form a first cemented lens group, the fifth lens L5 and the sixth lens L6 are cemented to form a second cemented lens group, and the seventh lens L7 and the eighth lens L8 are cemented to form a third cemented lens group, and the following conditions are met:

[0047]

[0048]

[0049] Among them, f1, f2, f3, f4, f5, f6, f7, f8, f9 are the focal lengths of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 respectively, f is the effective focal length of the lens, D is the entrance pupil diameter, and the units are all in mm.

[0050] In the embodiment, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9, the corresponding lens focal lengths are 103.5±5%, 45.4±5%, 30.5±5%, -25.9±5%, -14.1±5%, 17.1±5%, 14.3±5%, -7.4±5% and 28.1±5%, and the corresponding refractive indices are 1.95±0.1, 1.50±0.1, 1.59±0.1, 1.85±0.1, 1.85±0.1, 1.59±0.1, 1.95±0.1 , 1.77±0.1 and 1.52±0.1, and the corresponding object side curvature radii are 56.4±5%, 21.6±5%, 23.2±5%, -74.9±5%, 35.4±5%, 8.8±5%, -166.7±5%, -12.9±5% and 17.8±5%, respectively; the corresponding image side curvature radii are 126.5±5%, 468.4±5%, -74.9±5%, 31.8±5%, 8.8±5%, 48.8±5%, -12.9±5%, 10.9±5% and -73.8±5%, respectively; “-” indicates the negative direction; the units of the lens focal length and curvature radius are both mm.

[0051] In the embodiment, the axial thicknesses of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are 3.6 mm, 7.8 mm, 5.6 mm, 1.3 mm, 1.2 mm, 7.2 mm, 3.9 mm, 1.3 mm and 5.4 mm, respectively, and the axial spacings are 1.5 mm, 0.2 mm, 0 mm, 0.4 mm, 0 mm, 1.7 mm, 0 mm and 7.1 mm, respectively.

[0052] In the embodiment, the working wavelength band of the long focal length rifle scope lens is confocal with visible light and 850nm-940nm infrared light.

[0053] In the embodiment, the long focal length rifle scope lens, the image side of the nine-lens L9 is further provided with a protective glass CG.

[0054] In an embodiment, the telephoto rifle aiming lens further includes a stop STOP, and the stop is located between the eighth lens L8 and the ninth lens L9. The stop STOP is used to adjust the light flux according to actual conditions, which helps to improve the imaging quality.

[0055] The optical parameters of the rifle aiming lens in this embodiment are shown in Table 1.

[0056] Table 1

[0057]

[0058]

[0059] In the table, f1 to f9 correspond to the focal lengths of the first lens L1 to the ninth lens L9, n1 to n9 correspond to the refractive indexes of the first lens L1 to the ninth lens L9, R 11 , R 21 , R 31 , R 41 , R 51 , R 61 , R 71 , R 81 , R 91 Corresponding to the object side curvature radius of the first lens L1 to the ninth lens L9, R 12 , R 22 , R 32 , R 42 , R 52 , R 62 , R 72 , R 82 , R 92 The corresponding image side surface curvature radii are the first lens L1 to the ninth lens L9, and the unit is mm. Figure 3 In, R11 , R 21 , R 31 , R 41 , R 51 , R 61 , R 71 , R 81 , R 91 Corresponding to the object side surfaces of the first lens L1 to the ninth lens L9, R 12 , R 22 , R 32 , R 42 , R 52 , R 62 , R 72 , R 82 , R 92 They correspond to the image side surfaces of the first lens L1 to the ninth lens 9 in sequence, CG is the protection glass, and IMAGE is the image surface.

[0060] According to the above data, the effective focal length f of the lens in this embodiment is 60mm, the entrance pupil diameter D is 30mm, and Figure 2-4 It can be seen that the lens does not have serious defocusing phenomenon when the MTF curve is at a spatial frequency of 125lp / mm under the conditions of room temperature 20℃, low temperature -30℃, and high temperature 70℃. Figure 5-6 It can be seen that under visible light, 850nm, and 940nm conditions, there is no serious defocusing phenomenon when the MTF curve is at a spatial frequency of 125lp / mm. The nine glass spherical lenses used can effectively improve the imaging quality of the lens, with a total length of about 57mm. And the aperture FNO.2.0 meets the requirements of clear imaging in weak light and a longer field of view.

[0061] The above-mentioned embodiments only express one or several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A long focal length rifle scope lens, characterized in that: The optical system is composed of nine lenses, including a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, and a ninth lens L9, which are arranged in sequence from the object side to the image side. Among them: The first lens L1 is a convex-concave glass spherical lens with positive power; The second lens L2 is a convex-concave glass spherical lens with positive power; The third lens L3 is a biconvex glass spherical lens with positive power; The fourth lens L4 is a biconcave glass spherical lens with negative optical power; The fifth lens L5 is a convex-concave glass spherical lens with negative optical power; The sixth lens L6 is a convex-concave glass spherical lens with positive refractive power; The seventh lens L7 is a meniscus glass spherical lens with positive refractive power; The eighth lens L8 is a biconcave glass spherical lens with negative optical power; The ninth lens L9 is a biconvex glass spherical lens with positive refractive power; The third lens L3 and the fourth lens L4 are cemented together to form a first cemented lens group, the fifth lens L5 and the sixth lens L6 are cemented together to form a second cemented lens group, and the seventh lens L7 and the eighth lens L8 are cemented together to form a third cemented lens group, and the following conditions are met: Among them, f1, f2, f3, f4, f5, f6, f7, f8, f9 are the focal lengths of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 respectively, f is the effective focal length of the lens, D is the entrance pupil diameter, and the units are all in mm.

2. The long focal length rifle scope lens according to claim 1, characterized in that: The focal lengths of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9 are 103.5±5%, 45.4±5%, 30.5±5%, -25.9±5%, -14.1±5%, 17.1±5%, 14.3±5%, -7.4±5% and 28.1±5% respectively, and the refractive indices are 1.95±0.1, 1.50±0.1, 1.59±0.1, 1.85±0.1, 1.85±0.1, 1.59±0.1, 1.95±0.1, 1 .77±0.1 and 1.52±0.1, and the corresponding object side curvature radii are 56.4±5%, 21.6±5%, 23.2±5%, -74.9±5%, 35.4±5%, 8.8±5%, -166.7±5%, -12.9±5% and 17.8±5% respectively; the corresponding image side curvature radii are 126.5±5%, 468.4±5%, -74.9±5%, 31.8±5%, 8.8±5%, 48.8±5%, -12.9±5%, 10.9±5% and -73.8±5% respectively; "-" indicates the negative direction; the units of lens focal length and curvature radius are both mm.

3. The long focal length rifle scope lens according to claim 1, characterized in that: The on-axis thicknesses of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are successively 3.6 mm, 7.8 mm, 5.6 mm, 1.3 mm, 1.2 mm, 7.2 mm, 3.9 mm, 1.3 mm, and 5.4 mm, and the on-axis spacings are successively 1.5 mm, 0.2 mm, 0 mm, 0.4 mm, 0 mm, 1.7 mm, 0 mm, 7.1 mm.

4. The long focal length rifle scope lens according to claim 1, characterized in that: The Abbe numbers corresponding to the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 are successively 18.0, 81.6, 68.6, 30.1, 23.8, 68.6, 18.0, 49.6, and 64.

2.

5. The long focal length rifle scope lens according to claim 1, characterized in that: The optical total length TTL of the long focal length gun sight lens and the semi-image height IH corresponding to the maximum field of view angle satisfy: 13.0 < TTL / IH < 13.

1.

6. The long focal length rifle scope lens according to claim 1, characterized in that: The effective focal length f of the long focal length gun sight lens and the semi-image height IH corresponding to the maximum field of view angle satisfy: 0.06 < IH / f < 0.08; the optical total length TTL of the long focal length gun sight lens and the effective focal length f of the lens satisfy: 0.9 < TTL / f < 1.

0.

7. The long focal length rifle scope lens according to claim 1, characterized in that: The working wavelength band of the long focal length gun sight lens is confocal for visible light and infrared light from 850 nm to 940 nm.

8. The long focal length rifle scope lens according to claim 1, characterized in that: A protective glass CG is further provided on the image side of the ninth lens L9.

9. The long focal length rifle scope lens according to claim 1, characterized in that: The long focal length gun sight lens further includes a diaphragm STOP, and the diaphragm STOP is located between the eighth lens L8 and the ninth lens L9.

Images