Zoom lenses and guns

Abstract

The present invention discloses a zoom lens and a firearm. The zoom lens includes a lens barrel and a first lens group, a second lens group, a third lens group, and a fourth lens group arranged in sequence from the object side to the image side. The image plane size is set to φ12 mm. By reasonably arranging the four lens groups and conditionally limiting the ratio of the focal length of the zoom lens at the wide-angle end and the focal length of each lens group, a focal length fw of 25.6 mm at the wide-angle end and a focal length ft of 249.7 mm at the telephoto end are achieved. The aperture number at the wide-angle end reaches 4.51, and the aperture number at the telephoto end reaches 7.65. The optical distortion range is controlled between -0.8% and 0.8%. The total optical length (TTL) of the zoom lens is 199 mm. By setting the sixth lens, the eighth lens, and the twelfth lens as glass aspheric lenses, the same performance as in the prior art can be achieved with a smaller number of glass aspheric lenses, the cost is low, and in the case of a telephoto lens, good day and night confocal characteristics are still achieved, meeting the use requirements of most small and medium-caliber sniper rifles.

Description

Technical Field

[0001] The present invention relates to the technical field of optical system design, and in particular to a zoom lens and a gun. Background Art

[0002] Low-light-level imaging technology plays a crucial role in a military's nighttime combat capabilities. While widely used in night vision, low-light-level sights offer clear imaging and high resolution, they are inoperable during the day, significantly hindering military operations. Developing a lightweight, highly accurate, and well-matched riflescope objective lens is crucial to addressing this issue. Summary of the Invention

[0003] The main purpose of the present invention is to provide a zoom lens and a gun, aiming to provide a zoom lens with light weight, high aiming accuracy and good day and night confocal performance.

[0004] To achieve the above object, the present invention provides a zoom lens having an object side and an image side disposed opposite to each other along an optical axis. The zoom lens includes a lens barrel and a plurality of lens groups disposed within the lens barrel. The plurality of lens groups include:

[0005] a first lens group fixedly disposed in the lens barrel, the first lens group comprising a first lens, a second lens, a third lens, and a fourth lens arranged in sequence from the object side to the image side;

[0006] a second lens group movably arranged along an extension direction of the optical axis, the second lens group comprising a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side;

[0007] a third lens group movably arranged along an extension direction of the optical axis, the second lens group and the third lens group being configured to cause the zoom lens to zoom from a wide-angle end to a telephoto end when moving toward the image side, the third lens group including an eighth lens and a ninth lens arranged in sequence from the object side to the image side; and

[0008] a fourth lens group movably arranged along an extension direction of the optical axis to focus the zoom lens when moving along the optical axis, the fourth lens group comprising a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object side to the image side;

[0009] Wherein, the sixth lens, the eighth lens, and the twelfth lens are configured as glass aspherical lenses.

[0010] Optionally, the optical focal power of the first lens group is positive, the optical focal power of the second lens group is negative, the optical focal power of the third lens group is positive, and the optical focal power of the fourth lens group is positive;

[0011] Among them, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the zoom lens satisfies the following conditions:

[0012] 0.173 < fw / f1 < 0.259, and -0.958 < fw / f2 < -0.639, and 0.322 < fw / f3 < 0.483, and 0.341 < fw / f4 < 0.511.

[0013] Optionally, the first lens has a negative optical power, the second lens has a positive optical power, the third lens has a positive optical power, and the fourth lens has a negative optical power;

[0014] The first lens and the second lens are adhesively connected;

[0015] The focal length of the first lens is f11, the focal length of the second lens is f12, the focal length of the third lens is f13, the focal length of the fourth lens is f14, and the lenses within the first lens group satisfy the following conditions:

[0016] -1.960 < f1 / f11 < -1.306, and 1.151 < f1 / f12 < 1.726, and 1.565 < f1 / f13 < 2.348, and -1.121 < f1 / f14 < -0.747.

[0017] Optionally, the fifth lens has a negative optical power, the sixth lens has a negative optical power, and the seventh lens has a positive optical power;

[0018] The focal length of the fifth lens is f21, the focal length of the sixth lens is f22, the focal length of the seventh lens is f23, and the lenses within the second lens group satisfy the following conditions:

[0019] 0.396 < f2 / f21 < 0.594, and 1.499 < f2 / f22 < 2.248, and -1.207 < f2 / f2 < -0.804.

[0020] Optionally, the eighth lens has a positive optical power, and the ninth lens has a negative optical power;

[0021] The focal length of the eighth lens is f31, the focal length of the ninth lens is f32, and the lenses within the third lens group satisfy the following conditions:

[0022] 2.749 < f3 / f31 < 4.124, and -4.026 < f3 / f32 < -2.684.

[0023] Optionally, the tenth lens has a positive optical power, the eleventh lens has a negative optical power, and the twelfth lens has a positive optical power;

[0024] The tenth lens and the eleventh lens are adhesively connected;

[0025] The focal length of the tenth lens is f41, the focal length of the eleventh lens is f42, and the focal length of the twelfth lens is f43. The lenses within the fourth lens group satisfy the following conditions:

[0026] 2.930 < f4 / f41 < 4.396, and -7.967 < f4 / f42 < -5.311, and 2.770 < f4 / f43 < 4.155.

[0027] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the seventh lens, the ninth lens, the tenth lens, and the eleventh lens are all glass spherical lenses.

[0028] Optionally, the zoom lens satisfies the following conditions:

[0029] Where is the effective clear aperture of the first lens, and TTL is the overall optical length of the zoom lens.

[0030] Optionally, the zoom lens satisfies the following conditions: 0.254 < ΔZ1

[0031] , W-T ,

[0030] , W-T ,

[0034] , ,

[0033] , ,

[0032] ,

[0028] , , , W-T , , W-T ,

[0029] , , , , / TTL < 0.329, and 0.086 < ΔZ2 W-T / TTL < 0.112;

[0031] Where ΔZ1 W-T is the relative displacement of the fifth lens when the zoom lens is in the wide-angle end position and when the zoom lens is in the telephoto end position, and ΔZ2 W-T is the relative displacement of the eighth lens when the zoom lens is in the wide-angle end position and when the zoom lens is in the telephoto end position, and TTL is the overall optical length of the zoom lens.

[0032] The present invention also provides a firearm, the firearm includes a zoom lens, the zoom lens has an object side and an image side disposed oppositely along the optical axis direction, the zoom lens includes a lens barrel and a plurality of lens groups disposed in the lens barrel, and the plurality of lens groups include:

[0033] A first lens group, fixedly disposed in the lens barrel, the first lens group includes a first lens, a second lens, a third lens, and a fourth lens sequentially arranged from the object side to the image side;

[0034] a second lens group movably arranged along an extension direction of the optical axis, the second lens group comprising a fifth lens, a sixth lens, and a seventh lens arranged in sequence from the object side to the image side;

[0035] a third lens group movably arranged along an extension direction of the optical axis, the second lens group and the third lens group being configured to cause the zoom lens to zoom from a wide-angle end to a telephoto end when moving toward the image side, the third lens group including an eighth lens and a ninth lens arranged in sequence from the object side to the image side; and

[0036] a fourth lens group movably arranged along an extension direction of the optical axis to focus the zoom lens when moving along the optical axis, the fourth lens group comprising a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object side to the image side;

[0037] Wherein, the sixth lens, the eighth lens, and the twelfth lens are configured as glass aspherical lenses.

[0038] In the technical solution provided by the present invention, the second lens group, the third lens group and the fourth lens group are movably mounted on the lens barrel along the optical axis direction, the second lens group and the third lens group are used for zooming, and the fourth lens group moves in coordination along the optical axis direction to perform mobile focusing corresponding to the positions, imaging wavelength and imaging object distance of the second lens group and the third lens group, so that the zoom lens can maintain clear imaging on the image plane during zooming, the image plane size is set to φ12mm, and through the reasonable arrangement of the four lens groups and the conditional limit of the ratio of the focal length of the zoom lens at the wide-angle end and the focal length of each lens group The zoom lens has a focal length fw of 25.6 mm at the wide-angle end and a focal length ft of 249.7 mm at the telephoto end. The aperture number at the wide-angle end reaches 4.51, and the aperture number at the telephoto end reaches 7.65. The optical distortion range is controlled between -0.8% and 0.8%. The total optical length TTL of the zoom lens is 199 mm. By setting the sixth lens, the eighth lens, and the twelfth lens as glass aspherical lenses, the same performance as in the prior art can be achieved with a smaller number of glass aspherical lenses, which is low in cost. In addition, in the case of long focus, the lens still has good day and night confocal characteristics, meeting the use requirements of most small and medium-caliber sniper rifles. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0040] Figure 1 A schematic structural diagram of the first embodiment of the zoom lens provided by the present invention when it is at the wide-angle end;

[0041] Figure 2 This is a structural diagram of the zoom lens at an intermediate magnification;

[0042] Figure 3 This is a schematic diagram of the structure of the zoom lens at the telephoto end;

[0043] Figure 4 for Figure 1 Aberration diagram of the zoom lens at the wide-angle end;

[0044] Figure 5 for Figure 1 Field curvature / distortion diagram of the zoom lens at the wide-angle end;

[0045] Figure 6 for Figure 2 Spherical aberration diagram of the zoom lens at intermediate magnifications;

[0046] Figure 7 for Figure 2 Field curvature / distortion diagram for the zoom lens at intermediate magnifications;

[0047] Figure 8 for Figure 3 Aberration diagram of the zoom lens at the telephoto end;

[0048] Figure 9 for Figure 3 Field curvature / distortion diagram of the zoom lens at the telephoto end.

[0049] Description of Figure Numbers:

[0050] Label name Label name 1 First lens group 3 The third lens group 11 First lens 31 Eighth lens 12 Second lens 32 Ninth lens 13 The third lens 4 Fourth lens group 14 Fourth lens 41 Tenth lens 2 Second lens group 42 Eleventh lens 21 Fifth lens 43 Twelfth lens 22 Sixth lens 5 Image plane 23 Seventh lens 6 aperture

[0051] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0053] It should be noted that if a directional indication is involved in an embodiment of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0054] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0055] Low-light-level imaging technology plays a crucial role in a military's nighttime combat capabilities. Low-light-level sights, widely used in night vision applications, offer clear imaging and high resolution. However, mainstream high-precision riflescope objectives currently on the market typically utilize multiple glass aspherical lenses to enhance resolution, resulting in high manufacturing costs. Furthermore, most lack day / night confocal capabilities, rendering them inoperable during the day. This has limited the development of dual-use and low-cost riflescopes.

[0056] The present invention provides a zoom lens, which is a low-cost zoom lens. Figures 1 to 9 , the accompanying drawings show a specific embodiment of the zoom lens.

[0057] Figures 1 to 9 This is an embodiment of the zoom lens provided by the present invention.

[0058] Please refer to Figures 1 to 3The zoom lens has an object side and an image side that are arranged opposite to each other along the optical axis. The zoom lens includes a lens barrel (not shown in the figure) and a plurality of lens groups. The lens barrel extends along the optical axis. The lens groups are arranged in the lens barrel. The plurality of lens groups include a first lens group 1, a second lens group 2, a third lens group 3, a fourth lens group 4 and an image plane 5 that are arranged in sequence from the object side to the image side. The first lens group 1 is fixed in the lens barrel. The first lens group 1 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14 that are arranged in sequence from the object side to the image side. The second lens group 2 is movably arranged along the extension direction of the optical axis. The second lens group 2 includes a fifth lens 2 that is arranged in sequence from the object side to the image side. 1, a sixth lens 22 and a seventh lens 23; the third lens group 3 is movably arranged along the extension direction of the optical axis, the second lens group 2 and the third lens group 3 are used to enable the zoom lens to zoom from the wide-angle end to the telephoto end when moving toward the image side, the third lens group 3 includes an eighth lens 31 and a ninth lens 32 arranged in sequence from the object side to the image side; the fourth lens group 4 is movably arranged along the extension direction of the optical axis to enable the zoom lens to focus when moving along the optical axis direction, the fourth lens group 4 includes a tenth lens 41, an eleventh lens 42 and a twelfth lens 43 arranged in sequence from the object side to the image side; wherein the sixth lens 22, the eighth lens 31 and the twelfth lens 43 are configured as glass aspherical lenses.

[0059] It should be noted that the characteristic of aspheric lenses is that the curvature changes continuously from the center of the lens to the periphery. Unlike spherical lenses with constant curvature from the center of the lens to the periphery, aspheric lenses have better curvature radius characteristics and have the advantages of improving distortion aberration and improving astigmatism aberration. After using aspheric lenses, the aberrations that occur during imaging can be eliminated as much as possible, thereby improving the imaging quality of the lens. The use of glass lenses can reduce the impact of temperature on the optical performance of the lens.

[0060] It should be noted that the second lens group 2 is used for zooming when it moves along the extension direction of the optical axis, and the third lens group 3 and the fourth lens group 4 are driven by an external force to move and focus along the optical axis corresponding to the position of the second lens group 2, the imaging wavelength, and the imaging object distance, so that the zoom lens maintains a clear image on the image plane 5 during the zooming process.

[0061] It should also be noted that the second lens group 2, the third lens group 3, and the fourth lens group 4 can all be driven by an external force to move along the optical axis, wherein the external force can be driven by a driving motor or manually adjusted without limitation.

[0062] In the technical solution provided by the present invention, the second lens group 2, the third lens group 3, and the fourth lens group 4 are movably mounted on the lens barrel along the optical axis direction. The second lens group 2 and the third lens group 3 are used for zooming, and the fourth lens group 4 moves coordinately along the optical axis direction to perform moving focusing corresponding to the positions of the second lens group 2 and the third lens group 3, the imaging wavelength, and the imaging object distance, so that the image plane 5 remains in clear focus during the zooming process of the zoom lens. The size of the image plane 5 is set to φ12mm. Through the reasonable setting of the four lens groups and the conditional limitation of the ratio of the focal length of the wide-angle end of the zoom lens to the focal lengths of each lens group, the focal length fw at the wide-angle end is 25.6mm, and the focal length ft at the telephoto end is 249.7mm; the aperture number at the wide-angle end reaches 4.51, and the aperture number at the telephoto end reaches 7.65. The optical distortion range is controlled between -0.8% and 0.8%. And the total optical length TTL of the zoom lens is 199mm. By setting the sixth lens 22, the eighth lens 31, and the twelfth lens 43 as glass aspherical lenses, the same performance as in the prior art can be achieved with a smaller number of glass aspherical lenses, with low cost, and still having good day-night co-focus characteristics in the case of long focal lengths, meeting the usage requirements of most medium and small-caliber sniper rifles.

[0063] It should be noted that in terms of optical performance, the light transmittance of the glass lens reaches 99%. In the prior art, in order to enable the zoom lens of the monitoring device to achieve the performance of the zoom lens, whether it is a spherical lens or an aspherical lens, the glass material will be used. And in the present invention, by only setting the sixth lens 22, the eighth lens 31, and the twelfth lens 43 as glass aspherical lenses, the same performance as in the prior art can be achieved with a smaller number of glass aspherical lenses.

[0064] Specifically, the optical power of the first lens group 1 is positive, the optical power of the second lens group 2 is negative, the optical power of the third lens group 3 is positive, and the optical power of the fourth lens group 4 is positive;

[0065] Among them, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group 1 is f1, the focal length of the second lens group 2 is f2, the focal length of the third lens group 3 is f3, and the focal length of the fourth lens group 4 is f4. The zoom lens satisfies the following conditions:

[0066] 0.173 < fw / f1 < 0.259, and -0.958 < fw / f2 < -0.639, and 0.322 < fw / f3 < 0.483, and 0.341 < fw / f4 < 0.511.

[0067] In a specific embodiment, the ratio of the focal length of the zoom lens at the wide-angle end to the focal lengths of each lens group is as follows:

[0068] fw / f1 = 0.208; fw / f2 = -0.766; fw / f3 = 0.386; fw / f4 = 0.409.

[0069] Specifically, the first lens 11 has a negative optical power, the second lens 12 has a positive optical power, the third lens 13 has a positive optical power, and the fourth lens 14 has a negative optical power; the focal length of the first lens 11 is f11, the focal length of the second lens 12 is f12, the focal length of the third lens 13 is f13, and the focal length of the fourth lens 14 is f14. The lenses within the first lens group 1 satisfy the following conditions:

[0070] -1.960 < f1 / f11 < -1.306, and 1.151 < f1 / f12 < 1.726, and 1.565 < f1 / f13 < 2.348, and -1.121 < f1 / f14 < -0.747.

[0071] More specifically, in this embodiment, the first lens 11 is a convex-concave spherical lens with a negative optical power, that is, the object side of the first lens 11 is convex and the image side is concave. The second lens 12 is a biconvex spherical lens with a positive optical power, the third lens 13 is a biconvex spherical lens with a positive optical power, and the fourth lens 14 is a biconcave spherical lens with a negative optical power. The ratio of the focal length of the first lens group 1 to the focal lengths of each lens is specifically as follows: f1 / f11 = -1.568; f1 / f12 = 1.381; f1 / f13 = 1.878; f1 / f14 = -0.897.

[0072] More specifically, in this embodiment, the focal length values of the first lens group 1 and each lens therein are: f1 = 123.3; f11 = -78.630; f12 = 89.257; f13 = 65.634; f14 = -137.463.

[0073] Specifically, the fifth lens 21 has a negative optical power, the sixth lens 22 has a negative optical power, and the seventh lens 23 has a positive optical power; the focal length of the fifth lens 21 is f21, the focal length of the sixth lens 22 is f22, and the focal length of the seventh lens 23 is f23. The lenses within the second lens group 2 satisfy the following conditions:

[0074] 0.396 < f2 / f21 < 0.594, and 1.499 < f2 / f22 < 2.248, and -1.207 < f2 / f23 < -0.804.

[0075] More specifically, in this embodiment, the fifth lens 21 is a biconcave spherical lens with a negative optical power, the sixth lens 22 is a biconcave aspherical lens with a negative optical power, and the seventh lens 23 is a biconvex spherical lens with a positive optical power; the focal length ratios of the second lens group 2 to each of the lenses therein are as follows:

[0076] f2 / f21 = 0.475; f2 / f22 = 1.798; f2 / f23 = -0.965.

[0077] More specifically, in this embodiment, the focal length values of the second lens group 2 and each of the lenses in the second lens group 2 are: f2 = -33.4; f21 = -70.219; f22 = -18.567; f23 = 34.590.

[0078] Specifically, the eighth lens 31 has a positive optical power, and the ninth lens 32 has a negative optical power; the focal length of the eighth lens 31 is f31, and the focal length of the ninth lens 32 is f32. Each lens in the third lens group 3 satisfies the following conditions:

[0079] 2.749 < f3 / f31 < 4.124, and -4.026 < f3 / f32 < -2.684.

[0080] More specifically, the eighth lens 31 is a biconvex aspherical lens with a positive optical power, and the ninth lens 32 is a biconcave spherical lens with a negative optical power. The focal length ratios of the third lens group 3 to each of the lenses therein are as follows:

[0081] f3 / f31 = 3.299; f3 / f32 = -3.221.

[0082] More specifically, in this embodiment, the focal length values of the second lens group 2 and each of the lenses in the second lens group 2 are: f3 = 66.3; f31 = 20.087; f32 = -20.573.

[0083] Specifically, the tenth lens 4 has a positive optical power, the eleventh lens 42 has a negative optical power, and the twelfth lens 43 has a positive optical power; the tenth lens 41 and the eleventh lens 42 are adhesively connected;

[0084] The focal length of the tenth lens 41 is f41, the focal length of the eleventh lens 42 is f42, and the focal length of the twelfth lens 43 is f43. Each lens in the fourth lens group 4 satisfies the following conditions:

[0085] 2.930 < f4 / f41 < 4.396, and -7.967 < f4 / f42 < -5.311, and 2.770 < f4 / f43 < 4.155.

[0086] More specifically, in this embodiment, the tenth lens 41 is a biconvex spherical lens with a positive optical power, the eleventh lens 42 is a biconcave aspherical lens with a positive optical power, and the twelfth lens 43 is a biconvex aspherical lens with a negative optical power; the focal length ratios of the fourth lens group 4 to each lens therein are as follows:

[0087] f4 / f41 = 3.516; f4 / f42 = -6.374; f4 / f43 = 3.324.

[0088] More specifically, in this embodiment, the focal length values of the fourth lens group 4 and each lens in the fourth lens group 4 are: f4 = 62.6; f41 = 17.806; f42 = -9.824; f43 = 18.835.

[0089] Specifically, in order to ensure the stability of the zoom lens against temperature changes, the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 21, the seventh lens 23, the ninth lens 32, the tenth lens 41, and the eleventh lens 42 are all glass spherical lenses. Since glass lenses are not easily affected by thermal expansion and contraction and do not suffer from focus shift, glass lenses can well resist the problem of lens deformation due to heat, maintain high precision of the lens for a long time, and reduce costs while ensuring image quality and reliability with spherical lenses, having a lower assembly sensitivity and improving the yield of finished products.

[0090] Furthermore, in order to reduce light energy loss, increase imaging clarity, protect the scale surface, and further optimize the processing flow to meet the design requirements, in this embodiment, the first lens 11 and the second lens 12 are adhesively connected, and the tenth lens 41 and the eleventh lens 42 are adhesively connected. Thus, by reasonably using adhesive parts, the optical components can improve the image quality of the optical system.

[0091] With such settings, by reasonably distributing the optical power of the lenses, adjusting the glass shape and material combination, effectively correcting chromatic aberration and secondary spectrum, compensating and canceling spherical aberration, coma, astigmatism, etc. on each lens, the effect of clear imaging can be achieved, and the optimal correction of high-order aberrations and chromatic aberration can be realized.

[0092] Specifically, in a specific embodiment, the refractive index, radius of curvature, and thickness interval of the lens material are as shown in the following table:

[0093]

[0094]

[0095] Furthermore, in this embodiment, the aspheric surface shape of the aspheric lens satisfies the following conditions:

[0096]

[0097] Where c is the curvature corresponding to the radius, y is the radial coordinate (its unit is the same as the lens length unit), k is the conic coefficient (when the k coefficient is less than -1, the surface curve is a hyperbola, when the k coefficient is equal to -1, it is a parabola, when the k coefficient is between -1 and 0, it is an ellipse, when the k coefficient is equal to 0, it is a circle, and when the k coefficient is greater than 0, it is an oblate), A, B, C, D, E, F, and G are high-order aspheric coefficients (please refer to Table 2 below). The above parameters can be used to set the shape and size of the lens object side and image side aspheric surfaces.

[0098] Table 2 Conic coefficients and aspheric coefficients corresponding to aspheric lenses

[0099]

[0100]

[0101] Specifically, the zoom lens further includes an aperture 6 , and the aperture 6 is located between the second lens group 2 and the third lens group 3 ; that is, the aperture 6 is located between the seventh lens 23 and the eighth lens 31 .

[0102] Specifically, in this embodiment, the zoom lens further includes a filter, which is located between the fourth lens group 4 and the image plane 5. The filter is used to filter out light of unnecessary wavelengths and stray light to reduce optical noise and ease difficulties for subsequent photoelectric module processing. The filter can also be used to adjust the color of the object during the final imaging, thereby improving the imaging quality.

[0103] Specifically, the image plane 5 can be understood as the surface of the photosensitive chip facing the object side, that is, it can be the surface of a camera element such as a CCD or CMOS. It can be understood that the light carrying information of the object can pass through the first lens group 1, the second lens group 2, the aperture 6, the third lens group 3, the fourth lens group 4, and the filter in sequence and finally form an image on the image plane 5.

[0104] Specifically, the zoom lens meets the following conditions: in, is the effective clear aperture of the first lens 11, and TTL is the total optical length of the zoom lens.

[0105] Specifically, the zoom lens satisfies the following conditions: 0.254<ΔZ1W-T / TTL<0.329, and 0.086<ΔZ2W-T / TTL<0.112; wherein ΔZ1W-T is the relative displacement of the fifth lens 21 when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, ΔZ2W-T is the relative displacement of the eighth lens 31 when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

[0106] Specifically, the size of the image plane 5 in this embodiment is set to φ12mm, achieving the following performance parameters:

[0107] The focal length at the wide-angle end is fw = 25.6 mm, the focal length at the telephoto end is ft = 249.7 mm; the aperture number at the wide-angle end is 4.51, the aperture number at the telephoto end is 7.65; the optical distortion range is between -0.8% and 0.8%; the total optical length TTL of the zoom lens is 199 mm.

[0108] Table 3 Zoom data of the zoom lens at wide-angle end, intermediate magnification position, and telephoto end

[0109] Wide-angle end Intermediate magnification Telephoto end T(7) 2.760 56.608 60.784 T(14) 59.024 5.176 1.000 T(15) 20.682 13.696 1.000 T(18) 3.614 18.174 53.923 T(23) 33.827 26.253 3.200

[0110] Table 4 Focal length values ​​of a zoom lens in a specific embodiment at the wide-angle end, intermediate magnification position, and telephoto end

[0111] Focal length / mm Wide-angle end 25.6 Intermediate magnification 139.6 Telephoto end 249.7

[0112] In this embodiment, please refer to Figures 1 to 3 , which is a schematic diagram of the structure of the zoom lens when it is at the wide-angle end, the intermediate magnification, and the telephoto end respectively; wherein the intermediate magnification can be understood as a schematic diagram of the position of each lens group in the zoom lens when the zoom lens is between the wide-angle end and the telephoto end.

[0113] Figures 4 and 5 The diagrams respectively show the longitudinal aberration and field curvature / distortion of the zoom lens at the wide-angle end. In the diagrams, S and T represent the aberration corresponding to the sagittal image plane and the meridional image plane, respectively.

[0114] Please refer to Figures 6 and 7 , are the aberration diagrams, field curvature diagrams / distortion diagrams when the zoom lens is at an intermediate magnification. S and T in the diagrams are the aberrations corresponding to the sagittal image plane and the meridional image plane, respectively.

[0115] Please refer to Figures 8 and 9, are the spherical aberration diagram and field curvature diagram / distortion diagram when the zoom lens is at the telephoto end, where S and T are the aberrations corresponding to the sagittal image plane and the meridional image plane, respectively.

[0116] As can be seen from the above figures, the spherical aberration, field curvature and distortion of the zoom lens in this embodiment can be well corrected at intermediate magnifications, the wide-angle end and the telephoto end respectively.

[0117] As can be seen from the above figures, the spherical aberration, field curvature and distortion of the zoom lens in this embodiment can be well corrected at intermediate magnifications, the wide-angle end and the telephoto end respectively.

[0118] In addition, the present invention further provides a firearm, comprising the zoom lens described in the above technical solution. Since the firearm comprises the zoom lens, the specific structure of the zoom lens is as described in the above embodiments. Since the zoom lens of the present firearm adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0119] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's description and drawings, or direct / indirect applications in other related technical fields, within the scope of the present invention are included in the patent protection scope of the present invention.

Claims

1. A zoom lens for a gun, characterized in that: The zoom lens has an object side and an image side that are oppositely arranged along the optical axis direction. The zoom lens includes a lens barrel and a plurality of lens groups disposed within the lens barrel. The plurality of lens groups include: A first lens group fixedly disposed within the lens barrel. The first lens group includes a first lens, a second lens, a third lens, and a fourth lens sequentially arranged from the object side to the image side; A second lens group movably disposed along the extension direction of the optical axis. The second lens group includes a fifth lens, a sixth lens, and a seventh lens sequentially arranged from the object side to the image side; A third lens group movably disposed along the extension direction of the optical axis. The second lens group and the third lens group are used to zoom the zoom lens from the wide-angle end to the telephoto end when moving toward the image side. The third lens group includes an eighth lens and a ninth lens sequentially arranged from the object side to the image side; and, A fourth lens group movably disposed along the extension direction of the optical axis to focus the zoom lens when moving along the optical axis direction. The fourth lens group includes a tenth lens, an eleventh lens, and a twelfth lens sequentially arranged from the object side to the image side; Wherein, the sixth lens, the eighth lens, and the twelfth lens are configured as glass aspherical lenses; The optical power of the first lens group is positive, the optical power of the second lens group is negative, the optical power of the third lens group is positive, and the optical power of the fourth lens group is positive; Wherein, the focal length of the zoom lens at the wide-angle end is fw, the focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the zoom lens satisfies the following conditions: 0.173 < fw / f1 < 0.259, and -0.958 < fw / f2 < -0.639, and 0.322 < fw / f3 < 0.483, and 0.341 < fw / f4 < 0.511; The zoom lens meets the following conditions: in, is the effective clear aperture of the first lens, and TTL is the total optical length of the zoom lens.

2. The zoom lens according to claim 1, wherein: The first lens has a negative optical power, the second lens has a positive optical power, the third lens has a positive optical power, and the fourth lens has a negative optical power; The first lens and the second lens are adhesively connected; The focal length of the first lens is f11, the focal length of the second lens is f12, the focal length of the third lens is f13, the focal length of the fourth lens is f14. Each lens within the first lens group satisfies the following conditions: -1.960 < f1 / f11 < -1.306, and 1.151 < f1 / f12 < 1.726, and 1.565 < f1 / f13 < 2.348, and -1.121 < f1 / f14 < -0.

747.

3. The zoom lens according to claim 1, wherein: The fifth lens has a negative optical power, the sixth lens has a negative optical power, and the seventh lens has a positive optical power; The focal length of the fifth lens is f21, the focal length of the sixth lens is f22, the focal length of the seventh lens is f23. Each lens within the second lens group satisfies the following conditions: 0.396 < f2 / f21 < 0.594, and 1.499 < f2 / f22 < 2.248, and -1.207 < f2 / f23 < -0.

804.

4. The zoom lens according to claim 1, wherein: The eighth lens has a positive optical power, and the ninth lens has a negative optical power; The focal length of the eighth lens is f31, and the focal length of the ninth lens is f32. Each lens in the third lens group satisfies the following conditions: 2.749 < f3 / f31 < 4.124, and -4.026 < f3 / f32 < -2.

684.

5. The zoom lens according to claim 1, wherein: The tenth lens has a positive optical power, the eleventh lens has a negative optical power, and the twelfth lens has a positive optical power; The tenth lens and the eleventh lens are adhesively connected; The focal length of the tenth lens is f41, the focal length of the eleventh lens is f42, and the focal length of the twelfth lens is f43. Each lens in the fourth lens group satisfies the following conditions: 2.930 < f4 / f41 < 4.396, and -7.967 < f4 / f42 < -5.311, and 2.770 < f4 / f43 < 4.

155.

6. The zoom lens according to claim 1, wherein: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the seventh lens, the ninth lens, the tenth lens, and the eleventh lens are all glass spherical lenses.

7. The zoom lens according to claim 1, wherein: The zoom lens satisfies the following conditions: 0.254<ΔZ1 W-T / TTL<0.329, and 0.086<ΔZ2 W-T / TTL<0.112; Among them, ΔZ1 W-T is the relative displacement of the fifth lens when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, ΔZ2 W-T is the relative displacement of the eighth lens when the zoom lens is at the wide-angle end position and when the zoom lens is at the telephoto end position, and TTL is the total optical length of the zoom lens.

8. A firearm, characterized in that: A zoom lens comprising the zoom lens according to any one of claims 1 to 7.

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