Zoom lens

Abstract

The zoom lens comprises a first fixed lens group, a zoom lens group, a diaphragm, a second fixed lens group, a focusing lens group and a third fixed lens group which are sequentially arranged from an object plane to an image plane along an optical axis, and the focal powers are respectively positive, negative, positive, positive and positive; the first fixed lens group consists of three lenses, and the focal powers of the three lenses are respectively negative, positive and positive; the zoom lens group is composed of four lenses, and the focal power of the four lenses is negative, negative, positive and negative. The second fixed lens group consists of four lenses, and the focal powers of the four lenses are respectively positive, negative, positive and negative; the focusing lens group is composed of four lenses, and the focal power is positive, negative, positive and negative. The third fixed lens group is composed of two lenses, and the focal powers of the two lenses are respectively positive and negative. The zoom lens can meet the use requirements of large aperture and clear imaging on a 1 / 1.2 ''target surface and at the wave band of 436-850 nm.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of optical devices, and in particular to a zoom lens. Background Art

[0002] ITS (Intelligent Traffic System, ITS) lens is a lens specially designed for image sensors. Among them, most of the ITS lenses commonly used on the market are fixed-focus lenses, with low image quality and poor tolerance in harsh environments; facing more complex usage environments, zoom lenses have gradually become the new favorite in the ITS field, but the types of zoom lenses for the ITS field on the market are extremely limited, and there are problems such as low image quality, too small focal length range, and small temperature application range, which have certain difficulties in practical application.

[0003] Therefore, it is particularly necessary to develop a zoom lens with large aperture, high definition, wide temperature range, and long focal length that meets the needs of ITS. Summary of the invention

[0004] The present application provides a zoom lens that can meet the use requirements of large aperture and clear imaging on a 1 / 1.2″ target surface and in a 405nm-656nm band.

[0005] The embodiment of the present application provides a zoom lens, comprising a first fixed lens group with positive optical power, a variator lens group with negative optical power, an aperture, a second fixed lens group with positive optical power, a focus lens group with positive optical power, and a third fixed lens group with positive optical power, which are arranged in sequence from an object plane to an image plane along an optical axis; the first fixed lens group and the second fixed lens group are fixed, and the variator lens group and the focus lens group move along the optical axis when zooming;

[0006] Along the optical axis from the object plane to the image plane:

[0007] The first fixed lens group includes a first lens with negative optical power, a second lens with positive optical power, and a third lens with positive optical power;

[0008] The variable power lens group includes a fourth lens with negative optical power, a fifth lens with negative optical power, a sixth lens with positive optical power and a seventh lens with negative optical power;

[0009] The second fixed lens group includes an eighth lens with positive optical power, a ninth lens with negative optical power, a tenth lens with positive optical power and an eleventh lens with negative optical power; the eighth lens is an aspherical lens; the second fixed lens group includes at least one aspherical lens;

[0010] The focusing lens group includes a twelfth lens with positive optical power, a thirteenth lens with negative optical power, a fourteenth lens with positive optical power and a fifteenth lens with negative optical power; the focusing lens group includes at least one aspherical lens;

[0011] The third fixed lens group includes a sixteenth lens with positive optical power and a seventeenth lens with negative optical power; the third fixed lens group includes at least one aspherical lens;

[0012] The zoom lens has a consistent aperture position relative to the image plane position at different focal lengths, and the aperture diameter is the same at different focal lengths, satisfying the following conditions: FNO≤1.50;

[0013] Wherein, FNO is the aperture number of the zoom lens at the full focal length.

[0014] Optionally, along the direction from the object side to the image side of the optical axis, the surface shape of each lens is:

[0015] The surface shape of the first lens is convex-concave; the surface shape of the second lens is convex-convex; the surface shape of the third lens is convex-concave;

[0016] The surface shape of the fourth lens is convex-concave, the surface shape of the fifth lens is concave-concave, the surface shape of the sixth lens is convex-concave, and the surface shape of the seventh lens is concave-convex or concave-flat;

[0017] The surface shape of the eighth lens is convex-convex, the surface shape of the ninth lens is concave-concave, the surface shape of the tenth lens is convex-convex; the surface shape of the eleventh lens is concave-flat;

[0018] The surface shape of the twelfth lens is convex-convex; the surface shape of the thirteenth lens is convex-concave; the surface shape of the fourteenth lens is convex-convex, and the surface shape of the fifteenth lens is concave-concave;

[0019] The surface shape of the sixteenth lens is a convex-convex surface, and the surface shape of the seventeenth lens is a concave-concave surface.

[0020] Optionally, the focal length of each lens group of the zoom lens and the focal length of the lens at the wide-angle end satisfy the following relationship:

[0021] 6.050≤F1 / FW≤6.243;-1.800≤F2 / FW≤-1.765;

[0022] 5.307≤F3 / FW≤6.284;1.879≤F4 / FW≤2.025;18.214≤F5 / FW≤33.289;

[0023] Among them, F1, F2, F3, F4, and F5 are the focal lengths of the first fixed lens group, the variable power lens group, the second fixed lens group, the focusing lens group, and the third fixed lens group respectively; and FW is the focal length of the wide-angle end of the zoom lens.

[0024] Optionally, the eighth lens is an aspherical lens; the twelfth lens is an aspherical lens; and the seventeenth lens is an aspherical lens.

[0025] Optionally, materials of the eighth lens, the twelfth lens and the seventeenth lens meet the following requirements:

[0026] 1.44≤nd8≤1.50;81.5≤vd8≤95.2;

[0027] 1.50≤nd12≤1.53;70.32≤vd12≤81.5;

[0028] 1.69≤nd17≤1.73;31.1≤vd17≤40.5;

[0029] Among them, nd8, nd12, and nd17 are the refractive indices of the eighth lens, the twelfth lens, and the seventeenth lens respectively, and vd8, vd12, and vd17 are the Abbe numbers of the eighth lens, the twelfth lens, and the seventeenth lens respectively.

[0030] Optionally, the first fixed lens group includes at least one cemented lens;

[0031] The variable magnification lens group includes at least one cemented lens;

[0032] The three lenses close to the image plane in the second fixed lens group form a triplet lens; or form a single lens and a doublet lens;

[0033] The three lenses close to the image plane in the focusing lens group form a triplet lens; or form a single lens and a doublet lens.

[0034] Optionally, a triplet lens formed by combining the ninth lens, the tenth lens and the eleventh lens satisfies:

[0035] -1.018≤F9-10-11 / FG3≤-0.897;

[0036] Among them, F9-10-11 represents the focal length of the combination of the ninth lens, the tenth lens and the eleventh lens, and FG3 represents the focal length of the second fixed lens group.

[0037] Optionally, the thirteenth lens, the fourteenth lens and the fifteenth lens are combined into a triplet lens, satisfying:

[0038] -2.337≤F13-14-15 / FG4≤-1.946;

[0039] Among them, F13-14-15 represents the focal length of the combination of the thirteenth lens, the fourteenth lens and the fifteenth lens, and FG4 represents the focal length of the focusing lens group.

[0040] Optionally, the variable power lens group and the focusing lens group satisfy the following relationship: 13.296≤S2 / S4≤14.391;

[0041] Among them, S2 is the maximum distance that the zoom lens group moves along the optical axis direction, and S4 is the maximum distance that the focus lens group moves along the optical axis direction.

[0042] Optionally, the total length of the zoom lens and the moving distance of the variable magnification lens group satisfy the following relationship:

[0043] 3.454≤TTL / S2≤3.504;

[0044] Wherein, TTL is the total length of the zoom lens, and S2 is the maximum distance that the zoom lens group moves along the optical axis.

[0045] The zoom lens provided in the embodiment of the present application includes a first fixed lens group, a variable magnification lens group, an aperture, a second fixed lens group, a focusing lens group, and a third fixed lens group, which are arranged in sequence along the optical axis from the object plane to the image plane, and the optical focal powers are positive, negative, positive, positive, and positive, respectively; the first fixed lens group is composed of three lenses, and the optical focal powers are negative, positive, and positive, respectively; the variable magnification lens group is composed of four lenses, and the optical focal powers are negative, negative, positive, and negative, respectively; the second fixed lens group is composed of four lenses, and the optical focal powers are positive, negative, positive, and negative, respectively; the focusing lens group is composed of four lenses, and the optical focal powers are positive, negative, positive, and negative, respectively; the third fixed lens group is composed of two lenses, and the optical focal powers are positive and negative, respectively. The zoom lens can meet the requirements of large aperture and clear imaging on a 1 / 1.2″ target surface and in the 436nm-850nm band. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 1 of the present application;

[0047] Figure 2 A schematic diagram of the structure of the zoom lens at the telephoto end provided in Embodiment 1 of the present application;

[0048] Figure 3 for Figure 1The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end;

[0049] Figure 4 for Figure 2 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the telephoto end;

[0050] Figure 5 for Figure 1 Provided is the ray fan diagram of the zoom lens at infinite object distance at the wide-angle end;

[0051] Figure 6 for Figure 2 Provided is the ray fan diagram of the zoom lens at the infinite object distance at the telephoto end;

[0052] Figure 7 for Figure 1 Provides a plot of the field curvature distortion of the zoom lens at infinite object distance at the wide-angle end;

[0053] Figure 8 for Figure 2 Provides a plot of the field curvature distortion of the zoom lens at infinite object distance at the telephoto end;

[0054] Fig. 9 for Figure 1 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end;

[0055] Fig.10 for Figure 2 The axial aberration curve of the zoom lens provided at infinite object distance at the telephoto end;

[0056] Fig.11 A schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 2 of the present application;

[0057] Fig.12 A schematic diagram of the structure of the zoom lens at the telephoto end provided in the second embodiment of the present application;

[0058] Fig.13 for Fig.11 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end;

[0059] Fig.14 for Fig.12 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the telephoto end;

[0060] Fig.15 for Fig.11 Provided is the ray fan diagram of the zoom lens at infinite object distance at the wide-angle end;

[0061] Fig.16 for Fig.12Provided is the ray fan diagram of the zoom lens at the infinite object distance at the telephoto end;

[0062] Fig.17 for Fig.11 Provides a plot of the field curvature distortion of the zoom lens at infinite object distance at the wide-angle end;

[0063] Fig.18 for Fig.12 Provides a plot of the field curvature distortion of the zoom lens at infinite object distance at the telephoto end;

[0064] Fig.19 for Fig.11 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end;

[0065] Fig. 20 for Fig.12 The axial aberration curve of the zoom lens provided at infinite object distance at the telephoto end;

[0066] Fig.21 A schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 3 of the present application;

[0067] Fig. 22 A schematic diagram of the structure of the zoom lens at the telephoto end provided in Embodiment 3 of the present application;

[0068] Fig.23 for Fig.21 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end;

[0069] Fig.24 for Fig. 22 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the telephoto end;

[0070] Fig.25 for Fig.21 Provided is the ray fan diagram of the zoom lens at infinite object distance at the wide-angle end;

[0071] Fig.26 for Fig. 22 Provided is the ray fan diagram of the zoom lens at the infinite object distance at the telephoto end;

[0072] Fig. 27 for Fig.21 Provides a plot of the field curvature distortion of the zoom lens at infinite object distance at the wide-angle end;

[0073] Fig.28 for Fig. 22 Provides a plot of the field curvature distortion of the zoom lens at infinite object distance at the telephoto end;

[0074] Fig.29 for Fig.21The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end;

[0075] Fig.30 for Fig. 22 The axial aberration curve of the zoom lens at infinite object distance at the telephoto end is provided. DETAILED DESCRIPTION

[0076] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only the parts related to the present application, rather than all structures, are shown in the accompanying drawings.

[0077] Figure 1 This is a schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 1 of the present application. Figure 2 This is a schematic diagram of the structure of the zoom lens at the telephoto end provided in the first embodiment of the present application. Figure 1 and Figure 2 A zoom lens provided in an embodiment of the present application includes a first fixed lens group G1 with positive optical focal length, a variator lens group G2 with negative optical focal length, an aperture STO, a second fixed lens group G3 with positive optical focal length, a focus lens group G4 with positive optical focal length, and a third fixed lens group G5 with positive optical focal length, which are arranged in sequence from an object plane to an image plane along an optical axis; the first fixed lens group G1 and the second fixed lens group G3 are fixed, and the variator lens group G2 and the focus lens group G4 move along the optical axis when zooming.

[0078] Along the optical axis from the object plane to the image plane:

[0079] The first fixed lens group G1 includes a first lens L1 having negative power, a second lens L2 having positive power, and a third lens L3 having positive power.

[0080] The variator lens group G2 includes a fourth lens L4 having negative power, a fifth lens L5 having negative power, a sixth lens L6 having positive power, and a seventh lens L7 having negative power.

[0081] The second fixed lens group G3 includes an eighth lens L8 with positive optical power, a ninth lens L9 with negative optical power, a tenth lens L10 with positive optical power and an eleventh lens L11 with negative optical power; the second fixed lens group G3 includes at least one aspherical lens.

[0082] The focusing lens group G4 includes a twelfth lens L12 with positive optical power, a thirteenth lens L13 with negative optical power, a fourteenth lens L14 with positive optical power and a fifteenth lens L15 with negative optical power; the focusing lens group G4 includes at least one aspherical lens.

[0083] The third fixed lens group G5 includes a sixteenth lens L16 with positive optical power and a seventeenth lens L17 with negative optical power; the third fixed lens group G5 includes at least one aspherical lens.

[0084] The zoom lens has a consistent aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, satisfying the following conditions: FNO≤1.50.

[0085] Wherein, FNO is the aperture number of the zoom lens at the full focal length.

[0086] Specifically, refer to Figure 1 and Figure 2 In the zoom lens provided in the embodiment of the present application, the first fixed lens group G1, the variable power lens group G2, the second fixed lens group G3, the focus lens group G4 and the third fixed lens group G5 can be arranged in a lens barrel ( Figure 1 and Figure 2 The first fixed lens group G1, the second fixed lens group G3 and the third fixed lens group G5 are fixed in the lens barrel. At this time, the first fixed lens group G1, the second fixed lens group G3 and the third fixed lens group G5 are stationary relative to the image plane IMA. The zoom lens group G2 and the focus lens group G4 can move back and forth along the optical axis in the lens barrel. Moving the zoom lens group G2 can play a role in zooming, and moving the focus lens group G4 can focus on the image. On the one hand, it can compensate for the aberration caused by the zoom movement of the zoom lens group G2 and effectively achieve the aberration balance of each focal length. On the other hand, it adjusts the distance between the lens and the object or the imaging plane to ensure the clear imaging of the object under different focal lengths. Through the joint movement of the zoom lens group G2 and the focus lens group G4, the focal length of the zoom lens can be continuously changed from wide angle to telephoto.

[0087] It can be understood that when the zoom lens achieves zooming by moving the variable magnification lens group G2 and the focusing lens group G4, the zoom lens is located at the wide-angle end when the focal length is short, and is located at the telephoto end when the focal length is longest. At the wide-angle end and the telephoto end, the zoom lens has different focal lengths and optical focal powers, and also has different shapes.

[0088] It should be noted that Figure 1 , Figure 2 The structural schematic diagrams corresponding to the subsequent embodiments are only structural illustrations, and the shapes such as aspherical surfaces are not represented according to the actual situation.

[0089] Furthermore, the focal power is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam. Its value is the reciprocal of the focal length, and it characterizes the ability of the zoom lens to deflect light. The larger the absolute value of the focal power, the stronger the ability to bend light, and the smaller the absolute value of the focal power, the weaker the ability to bend light. When the focal power is a positive number, the refraction of light is convergent; when the focal power is a negative number, the refraction of light is divergent. The focal power can be used to characterize a certain refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0090] Among them, the aperture STO includes an aperture aperture and a field aperture. The aperture aperture refers to the aperture that limits the light beam the most, and the field aperture refers to the aperture that limits the field of view (size) the most.

[0091] Reference Figure 1 and Figure 2 The front end of the aperture STO uses the first fixed lens group G1 with positive focal length and the variable magnification lens group G2 with negative focal length, which can ensure that a larger light aperture is generated after the light passes through, increase the aperture number of the zoom lens, and meet the use requirements under different conditions. The rear end of the aperture STO uses the second fixed lens group G3 with positive focal length, the focusing lens group G4 with positive focal length, and the third fixed lens group G5 with positive focal length. By reasonably matching the focal length of the rear end lens group, the aberration at the rear end of the lens can be corrected, and combined with the lens at the front end of the aperture STO, the imaging quality of the zoom lens can be stabilized.

[0092] Specifically, the aperture STO is set between the seventh lens L7 with negative focal power and the eighth lens L8 with positive focal power, which can adjust the propagation direction of the light beam emitted by the seventh lens L7 to the incident surface of the eighth lens L8, thereby limiting the light beam or field of view in the zoom lens, thereby improving the imaging quality of the zoom lens. In this way, by changing the position of the zoom lens group G2 and the focus lens group G4 on the optical axis, the zoom lens can be switched between the wide-angle end and the telephoto end at will.

[0093] Furthermore, the aperture diameter of the aperture STO at different focal lengths can be controlled to be the same, and the aperture number FNO of the zoom lens at all focal lengths is ≤1.50, which structurally reduces the aperture range, ensures that the movable group of the lens has a longer moving distance, reduces the size of the zoom lens, and can simultaneously achieve a higher imaging magnification to meet usage requirements under different conditions.

[0094] The embodiment of the present application reasonably allocates the number of lenses of the first fixed lens group G1, the zoom lens group G2, the second fixed lens group G3, the focusing lens group G4 and the third fixed lens group G5, as well as the optical focal length of each lens, so that each lens group and the optical focal length of each lens cooperate with each other to compensate for the aberration caused by the zooming movement of the zoom lens group G2, thereby effectively achieving aberration balance in each focal length and ensuring image clarity at different focal lengths.

[0095] Among them, along the direction from the object plane to the image plane along the optical axis, the surface of the lens adjacent to the object plane is the object side surface, and the surface of the lens adjacent to the image plane is the image side surface. Among them, the surface shape of each lens refers to the concave and convex shape of the object side surface and the image side surface along the optical axis direction. Specifically:

[0096] In the first fixed lens group G1 , the surface type of the first lens L1 is convex-concave; the surface type of the second lens L2 is convex-convex; and the surface type of the third lens L3 is convex-concave.

[0097] In the zoom lens group G2, the surface type of the fourth lens L4 is convex-concave, the surface type of the fifth lens L5 is concave-concave, the surface type of the sixth lens L6 is convex-concave, and the surface type of the seventh lens L7 is concave-convex or concave-flat.

[0098] In the second fixed lens group G3, the surface type of the eighth lens L8 is convex-convex, the surface type of the ninth lens L9 is concave-concave, the surface type of the tenth lens L10 is convex-convex; and the surface type of the eleventh lens L11 is concave-flat.

[0099] In the focusing lens group G4, the surface type of the twelfth lens L12 is convex-convex; the surface type of the thirteenth lens L13 is convex-concave; the surface type of the fourteenth lens L14 is convex-convex; and the surface type of the fifteenth lens L15 is concave-concave.

[0100] In the third fixed lens group G5, the surface type of the sixteenth lens L16 is convex-convex, and the surface type of the seventeenth lens L17 is concave-concave.

[0101] The concave lens has a diverging effect on the transmitted light, and the convex lens has a converging effect on the transmitted light. By properly setting the surface shapes of the first lens L1 to the seventeenth lens L17, clear imaging of the zoom lens at various focal lengths can be achieved.

[0102] Considering that aspherical lenses have a good ability to control high-order aberrations of optical systems, the second fixed lens group G3 includes at least one aspherical lens, the focusing lens group G4 includes at least one aspherical lens; and the third fixed lens group G5 includes at least one aspherical lens.

[0103] Exemplarily, the eighth lens L8 closest to the object plane in the second fixed lens group G3 is an aspherical lens; the twelfth lens L12 closest to the object plane in the focusing lens group G4 is an aspherical lens; and the seventeenth lens L17 closest to the object plane in the third fixed lens group G5 is an aspherical lens.

[0104] Specifically, the aperture STO is arranged between the seventh lens L7 and the eighth lens L8, and the eighth lens L8, the twelfth lens L12 and the seventeenth lens L17 are all aspherical lenses. When the light passes through the aperture STO, the use of the aspherical lens can well correct the aberration at the rear end of the aperture STO, and avoid the situation where the aberration is superimposed at the rear end of the lens, making it difficult to pull back the rear end, so that the imaging quality of the optical system can be stabilized by cooperating with the lens group at the rear end of the aperture STO.

[0105] In the embodiment of the present application, the aspherical lens of the zoom lens satisfies the following formula:

[0106]

[0107] Where Z is the axial distance from the curved surface at a position perpendicular to the optical axis at a height r to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; a4, a6, a8, a10, a12, a14, a16 are the high-order aspheric coefficients of the corresponding aspheric surface of the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order, a i r i The combination becomes the high-order terms corresponding to the aspheric surface, i = 4, 6, 8, 10, 12, 14, 16.

[0108] Among them, the cost of plastic lenses is much lower than that of glass lenses.

[0109] In the embodiment of the present application, one or more of the eighth lens L8, the twelfth lens L12 and the seventeenth lens L17 can be a plastic aspherical lens, which can greatly reduce the cost of the zoom lens; or, one of the eighth lens L8, the twelfth lens L12 and the seventeenth lens L17 can be a glass spherical lens, or a glass aspherical lens and a plastic aspherical lens can be mixed. The two types of materials, glass and plastic, can also compensate for each other and balance high and low temperatures, so that the zoom lens has the characteristics of stable high and low temperature performance, which is helpful to improve the environmental adaptability of the zoom lens.

[0110] It should be noted that the material of other lenses can be glass or plastic, which is not limited here. The material of the plastic aspherical lens can be various plastics known to those skilled in the art, and the material of the glass spherical lens can be various types of glass known to those skilled in the art, which is not elaborated or limited in the embodiments of the present application.

[0111] Based on the above embodiments, Figure 1-Figure 2 , each of the zoom lens group G2, the second fixed lens group G3 and the third fixed lens group G5 has at least one aspherical lens; when the eighth lens L8, the twelfth lens L12 and the seventeenth lens L17 are aspherical lenses, the materials of the eighth lens L8, the twelfth lens L12 and the seventeenth lens L17 meet the following requirements:

[0112] 1.44≤nd8≤1.50;81.5≤vd8≤95.2.

[0113] 1.50≤nd12≤1.53;70.32≤vd12≤81.5.

[0114] 1.69≤nd17≤1.73;31.1≤vd17≤40.5.

[0115] Among them, nd8, nd12, and nd17 are the refractive indices of the eighth lens L8, the twelfth lens L12, and the seventeenth lens L17, respectively, and vd8, vd12, and vd17 are the Abbe numbers of the eighth lens L8, the twelfth lens L12, and the seventeenth lens L17, respectively.

[0116] In order to ensure that the optical system can form stable images at full focal lengths, the commonly used method is to individually eliminate chromatic aberrations and control aberrations in each lens group. Considering that aspherical lenses have a good ability to control high-level aberrations of optical systems, during the zooming process, the present application adds an aspherical lens to each of the second fixed lens group G3, the focusing lens group G4, and the third fixed lens group G5. By reasonably matching the refractive index and Abbe number of the eighth lens L8, the twelfth lens L12, and the seventeenth lens L17, the aberrations of each group can be controlled to a great extent, ensuring that the light at the front end is smoothly emitted, ensuring resolution and image height, ensuring illumination, and improving the imaging quality of the lens.

[0117] In addition, considering that the properties of glass lenses are not sensitive to temperature, lenses using all-glass lenses have more uniform performance under different temperature conditions, and have the characteristics of stable high and low temperature performance, which can improve the environmental adaptability of zoom lenses. In the embodiments of the present application, the eighth lens L8, the twelfth lens L12, and the seventeenth lens L17 can also use glass aspherical lenses. In this way, the chromatic aberration and high-order aberration of the lens can be corrected to a large extent. Compared with plastic aspherical lenses, the range of options is also larger, and more diverse results can be used in structural selection, which improves the market competitiveness of the lens. In addition, the material of the glass spherical lens is various types of glass known to those skilled in the art, and the embodiments of the present application will not be repeated.

[0118] Based on the above embodiments, Figure 1-Figure 2 The first fixed lens group G1 includes at least one cemented lens.

[0119] For example, the first lens L1 and the second lens L2 of the first fixed lens group G1 are combined into a doublet lens. In other embodiments, the first lens L1 and the second lens L2 can also be used as two single lenses.

[0120] Specifically, the first lens L1 and the second lens L2 are combined into a double-cemented lens. The air gap between the first lens L1 and the second lens L2 can be effectively reduced, and the total length of the zoom lens can be reduced; the surface shape of the double-cemented lens after the first lens L1 and the second lens L2 are combined is convex-concave, and the double-cemented lens is conducive to the smooth collection of object light into the imaging system, and can correct high-order aberrations to a great extent. At the same time, this shape can better collect light with a large field of view angle, ensuring the imaging requirements of a wide angle and a large field of view.

[0121] Among them, the glued lens in the embodiment of the present application can also be called a glued lens group.

[0122] Further, the fifth lens L5 and the sixth lens L6 in the zoom lens group G2 are combined into a double-cemented lens. In other embodiments, the fifth lens L5 and the sixth lens L6 can also be used as two single lenses. Specifically, the surface shape of the double-cemented lens formed by the fifth lens L5 and the sixth lens L6 in the zoom lens group G2 is concave-concave, which can effectively reduce the air gap between the fifth lens L5 and the sixth lens L6, and reduce the total length of the zoom lens. When the light is diverged by the fifth lens L5 with a negative focal power and enters the sixth lens L6 with a positive focal power to converge, and then enters the seventh lens L7 with a negative focal power to diverge and enters the eighth lens L8 with a positive focal power to converge, the light can be diffused and focused for multiple alternating transmissions, so that the light can smoothly pass through the middle end of the lens, and before the light enters the second fixed lens group G3, the use of a cemented lens can reduce the chromatic aberration and aberration generated at the front end, further improving the imaging quality.

[0123] At the same time, the double cemented lens composed of the first lens L1 and the second lens L2 used in the first fixed lens group G1 and the double cemented lens composed of the fifth lens L5 and the sixth lens L6 used in the zoom lens group G2, the combination of two cemented lenses can also correct the high-order chromatic aberration and aberration of the lens, control the aberration balance of each group, and avoid serious aberration when the light enters the second fixed lens group G3 behind the aperture STO, thereby improving the imaging quality of the zoom lens.

[0124] Further, the ninth lens L9, the tenth lens L10 and the eleventh lens L11 of the second fixed lens group G3 are combined into a triplet lens; or the tenth lens L10 and the eleventh lens L11 are combined into a doublet lens for use.

[0125] Optionally, when the ninth lens L9, the tenth lens L10 and the eleventh lens L11 of the second fixed lens group G3 are combined into a triplet lens, the focal length of the combination of the ninth lens L19, the tenth lens L10 and the eleventh lens L11 and the focal length of the second fixed lens group G3 satisfy the following relationship:

[0126] -1.018≤F9-10-11 / FG3≤-0.897.

[0127] Wherein, F9-10-11 represents the focal length of the combination of the ninth lens L19, the tenth lens L10 and the eleventh lens L11, and FG3 represents the focal length of the second fixed lens group G3.

[0128] Specifically, when the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are combined into a triplet lens, the focal length of the triplet lens and the focal length of the second fixed lens group G3 are matched in the above manner, and when the light passes through the aperture STO, the use of the aspherical lens can well correct the aberration of the front zoom lens group G2 during the zoom movement process, and avoid the situation where the aberration is superimposed at the rear end of the lens, making it difficult to pull back the rear end. The cemented lens can further correct the high-order aberration and chromatic aberration generated by the front end and the lens group itself, and can effectively improve the image quality.

[0129] In some embodiments, the surface shape of the double cemented lens composed of the tenth lens L10 and the eleventh lens L11 in the second fixed lens group G3 is convex-flat. After being converged by the eighth lens L8 with a positive focal power, the light is diffused by the ninth lens L9 with a negative focal power, and then converged by the tenth lens L10 with a positive focal power and enters the eleventh lens L11 with a negative focal power for diffusion, so that the light passes smoothly through the middle end of the lens and before entering the third fixed lens group G5 at the rear end, the cemented lens is used to reduce the air gap between the tenth lens L10 and the eleventh lens L11, reduce the total length of the zoom lens, and at the same time reduce the chromatic aberration and aberration generated at the front end, further improving the imaging quality.

[0130] Furthermore, the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 in the focus lens group G4 are combined into a triplet lens. In other embodiments, the fourteenth lens L14 and the fifteenth lens L15 can also be combined into a doublet lens for use.

[0131] Optionally, when the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 in the focusing lens group G4 are combined into a triplet lens, the focal length of the combination of the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 and the focal length of the focusing lens group G4 need to satisfy the following relationship:

[0132] -2.337≤F13-14-15 / FG4≤-1.946.

[0133] Wherein, F13-14-15 represents the focal length of the combination of the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15, and FG4 represents the focal length of the focusing lens group G4.

[0134] Specifically, the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 in the focusing lens group G4 are combined into a triplet lens, and the focal length of the triplet lens and the focal length of the focusing lens group G4 are matched in the above-mentioned manner. During the zooming process of the optical system, the focusing lens group G4 can focus the optical system with a changed focal length. The use of aspherical lenses and cemented lenses can correct chromatic aberration and higher-order aberrations generated in the focusing lens group G4, greatly reducing the aberration pressure of other lens groups at different focal lengths, thereby achieving focusing of the optical system at all focal lengths.

[0135] In some embodiments, the surface of the double cemented lens formed by the fourteenth lens L14 and the fifteenth lens L15 is convex-concave, which can effectively reduce the air gap between the fourteenth lens L14 and the fifteenth lens L15, and reduce the total length of the zoom lens. When the light is converged by the fourteenth lens L14 with positive focal length and enters the fifteenth lens L15 with negative focal length, it is diffused and enters the third fixed lens group G5, which is beneficial to the full focal length aberration correction, and improves the pixel imaging quality and the finished product yield.

[0136] At the same time, the bonding setting can minimize or eliminate chromatic aberration, so that various aberrations of the zoom lens can be fully corrected. Under the premise of compact structure, it can improve resolution, optimize optical properties such as distortion, reduce light loss caused by reflection between lenses, and increase illumination, thereby improving image quality and improving the clarity of lens imaging. In addition, bonding lenses can also reduce the number of assembly parts between lenses, simplify the assembly procedures in the lens manufacturing process, reduce costs, and reduce the tolerance sensitivity of lens units due to tilt / eccentricity caused during the assembly process.

[0137] Based on the above embodiments, Figure 1-Figure 2 , the focal length of each lens group of the zoom lens and the focal length of the zoom lens at the wide-angle end satisfy the following relationship:

[0138] 6.050≤F1 / FW≤6.243;-1.800≤F2 / FW≤-1.765.

[0139] 5.307≤F3 / FW≤6.284; 1.879≤F4 / FW≤2.025; 18.214≤F5 / FW≤33.289. Among them, F1, F2, F3, F4, F5 are the focal lengths of the first fixed lens group G1, the zoom lens group G2, the second fixed lens group G3, the focus lens group G4 and the third fixed lens group G5 respectively; FW is the focal length of the zoom lens at the wide-angle end.

[0140] Specifically, matching the focal length of each lens group with the focal length of the wide-angle end of the zoom lens in the above-mentioned manner is conducive to achieving a reasonable combination of optical focal lengths, allowing light to pass through the lens more smoothly, and to a large extent correcting the influence of high-order aberrations on imaging quality, thereby expanding the field of view of the optical system and expanding the scope of use of the optical system.

[0141] Based on the above embodiments, Figure 1-Figure 2 , the zoom lens group G2 and the focus lens group G4 satisfy the following relationship: 13.296≤S2 / S4≤14.391.

[0142] Among them, S2 is the maximum distance that the zoom lens group G2 moves along the optical axis, and S4 is the maximum distance that the focus lens group G4 moves along the optical axis.

[0143] Specifically, by controlling the moving distance of the zoom lens group G2 and the focus lens group G4, the volume of the focus lens group G4 can be reduced to the greatest extent, and stable imaging of the full focal length can be achieved within a smaller moving range. At the same time, the total volume of the zoom lens can be reduced, and the lens volume can be reduced to a great extent, meeting the requirements of lens miniaturization.

[0144] Based on the above embodiments, Figure 1-Figure 2 , the total length of the zoom lens and the moving distances of the variable power lens group G2 and the focus lens group G4 satisfy the following relationship: 3.454≤TTL / S2≤3.504.

[0145] Wherein, TTL is the total length of the zoom lens, and S2 is the maximum distance that the zoom lens group G2 moves along the optical axis.

[0146] Specifically, by adopting the above-mentioned limitation on the total length of the variable-magnification lens group G2 and the zoom lens, the lens space can be compressed, thereby ensuring that the required imaging quality and variable-magnification degree are met under the condition of a small lens volume.

[0147] refer to Figure 1-Figure 2 A plane glass CG with a certain thickness is also provided between the seventeenth lens L17 and the image plane IMA, which plays a protective role and can filter out unnecessary stray light to improve the imaging quality of the zoom lens. For example, the imaging quality of the zoom lens can be improved by filtering out infrared light during the day through the plane glass CG.

[0148] In summary, the zoom lens provided in the embodiment of the present application can effectively achieve aberration balance in each focal length through reasonable matching of the optical power, refractive index, material, etc. of the five lens groups, ensure the clarity of the image under different focal lengths, and achieve the use requirements of large aperture and clear imaging on a 1 / 1.2″ target surface and in the 436nm-850nm band.

[0149] The zoom lens provided in the embodiment of the present application is applied in the ITS lens, which has the characteristics of high resolution, low distortion, high contrast, etc., and can provide clear, accurate, high-quality images. Its design takes into account the optical characteristics, mechanical structure and electronic interface, etc., and can effectively adapt to various complex environments.

[0150] Specific embodiments of the zoom lens applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0151] Embodiment 1

[0152] Continue to refer Figure 1-Figure 2 As shown, a zoom lens provided in Embodiment 1 of the present application includes a first fixed lens group G1 with positive optical focal length, a variator lens group G2 with negative optical focal length, an aperture STO, a second fixed lens group G3 with positive optical focal length, a focus lens group G4 with positive optical focal length, and a third fixed lens group G5 with positive optical focal length, which are arranged in sequence along the optical axis from the object plane to the image plane; the first fixed lens group G1 and the second fixed lens group G3 are fixed, and the variator lens group G2 and the focus lens group G4 move along the optical axis when zooming.

[0153] Along the optical axis from the object plane to the image plane:

[0154] The first fixed lens group G1 includes a first lens L1 with negative optical power, a second lens L2 with positive optical power, and a third lens L3 with positive optical power. The first lens L1 and the second lens L2 are combined into a doublet lens.

[0155] The zoom lens group G2 includes a fourth lens L4 with negative optical power, a fifth lens L5 with negative optical power, a sixth lens L6 with positive optical power, and a seventh lens L7 with negative optical power. The fifth lens L5 and the sixth lens L6 are combined into a doublet lens.

[0156] The second fixed lens group G3 includes an eighth lens L8 with positive optical power, a ninth lens L9 with negative optical power, a tenth lens L10 with positive optical power and an eleventh lens L11 with negative optical power; the eighth lens L8 is an aspherical lens, and the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are combined into a triplet lens.

[0157] The focusing lens group G4 includes a twelfth lens L12 with positive optical power, a thirteenth lens L13 with negative optical power, a fourteenth lens L14 with positive optical power and a fifteenth lens L15 with negative optical power; the twelfth lens L12 is an aspherical lens, and the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 are combined into a triplet lens.

[0158] The third fixed lens group G5 includes a sixteenth lens L16 with positive refractive power and a seventeenth lens L17 with negative refractive power; the seventeenth lens L17 is an aspherical lens,

[0159] The zoom lens has a consistent aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, satisfying the following conditions: FNO≤1.50.

[0160] Wherein, FNO is the aperture number of the zoom lens at the full focal length.

[0161] Among them, the plane glass CG is located on the image side of the seventeenth lens L17. The plane glass CG can protect the photosensitive chip in the imaging sensor. The imaging chip is used to convert the optical signal collected by the zoom lens into an electrical signal, thereby ensuring the imaging effect of the zoom lens.

[0162] For example, Table 1 details the specific optical and physical parameters of each lens in the zoom lens provided in Example 1 of the present application. The zoom lens in Table 1 corresponds to Figure 1 and Figure 2 Zoom lens shown.

[0163] Table 1 Design values ​​of optical physical parameters of zoom lens

[0164]

[0165]

[0166] Among them, the surface number S in Table 1 is numbered according to the surface order of each lens; "STO" represents the aperture of the zoom lens; IMA represents the image plane; the radius of curvature R represents the curvature of the lens surface, a positive value represents that the surface is bent toward the image plane, and a negative value represents that the surface is bent toward the object plane; "INF" represents that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the refractive index nd represents the ability of the material between the current surface and the next surface to deflect light, and the space represents that the current position is air with a refractive index of 1. The Abbe number vd represents the dispersion characteristics of the material between the current surface and the next surface to the light; the half-aperture represents half of the lens aperture. Among them, the more severe the medium dispersion, the smaller the Abbe number; conversely, the milder the medium dispersion, the larger the Abbe number.

[0167] Furthermore, Table 2 shows the values ​​of zoom intervals of the zoom lens at the wide-angle end and the telephoto end in Table 1 above, in millimeters (mm).

[0168] Table 2 Design values ​​of variable pitch of zoom lens

[0169] Wide angle Telephoto end Zoom interval 1 0.3 35.038 Zoom interval 2 35.038 0.3 Zoom interval 3 8.768 6.209 Zoom interval 4 2.965 5.524

[0170] The zoom intervals in Table 2 are different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0171] Combination Figure 1 , Figure 2 , Table 1 and Table 2, by adjusting the distances of the lens zoom interval 1, zoom interval 2, zoom interval 3, and zoom interval 4 at the wide-angle end and the telephoto end respectively, the zoom ratio of the zoom lens can be changed to have a larger zoom ratio.

[0172] In this embodiment, the aspherical lens of the zoom lens may satisfy the following formula:

[0173]

[0174] Where Z is the axial distance from the curved surface at a position perpendicular to the optical axis at a height r to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; a4, a6, a8, a10, a12, a14, a16 are the high-order aspheric coefficients of the corresponding aspheric surface of the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order, a i r i The combination becomes the high-order terms corresponding to the aspheric surface, i = 4, 6, 8, 10, 12, 14, 16.

[0175] Exemplarily, Table 3 describes in detail the aspheric coefficients of each lens in the first embodiment in a feasible implementation manner.

[0176] Table 3 Design values ​​of aspheric coefficients of each lens in zoom lens

[0177] Surface number k a4 a6 a8 14 0.489 -1.868697084661E-05 8.997606627708E-09 -6.077435496972E-10 15 43.085 1.172011650539E-06 6.007628742960E-08 -3.537983621171E-10 20 -2.198 1.042901558382E-05 2.352000612956E-08 -1.423149483927E-10 21 3.552 2.724207302418E-05 3.564540268473E-08 1.411205876428E-11 29 28.807 -2.823303763210E-04 4.104612872531E-06 -7.353654130158E-08 30 15.185 -3.674615492418E-04 3.782629376553E-06 -9.584065025111E-08

[0178] Surface number a10 a12 a14 a16 14 8.052745768235E-12 -4.057087114972E-14 7.864456546879E-18 9.633257011075E-20 15 6.031823548618E-12 -3.360195225187E-14 9.185680520942E-18 5.309168632812E-20 20 1.329607304492E-12 -5.738874013436E-16 -5.158503610601E-18 -3.266088504215E-20 21 1.338124155672E-12 -5.113223088374E-16 -2.435910081442E-18 -1.518751151539E-20 29 9.669385059189E-10 -6.793749345291E-12 3.914867145465E-15 -5.310255354775E-17 30 1.381916192917E-09 -1.180096352623E-11 4.362075998577E-15 1.979369534141E-16

[0179] In Table 3, -2.811720863650E-05 indicates that the coefficient a4 of the design value number of the aspheric coefficient of the surface sequence mirror S11 is -2.81172086365*10 -5 , and so on.

[0180] As shown in Table 4, the zoom lens of the first embodiment achieves the following technical indicators:

[0181] Table 4 Parameters of the zoom lens of Example 1

[0182] Wide angle Telephoto end Image size(mm) Φ13.10 Φ13.10 Focal length(mm) 14.974 50.00 Wavelength(nm) 436～850 436～850 Total optical length (mm) 120 120

[0183] Furthermore, the performance parameters of the zoom lens provided in Example 1 were tested, and the test results are as follows:

[0184] Figure 3 for Figure 1 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Figure 4 for Figure 2 The vertical axis chromatic aberration curve of the zoom lens provided is at infinite object distance at the telephoto end. Figure 3 and Figure 4 , the vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum image height; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Figure 3 , Figure 4 It can be seen that the vertical axis chromatic aberration of different wavelengths is controlled within a small range, indicating that the vertical axis chromatic aberration of the zoom lens at different focal lengths is well controlled and can meet the application requirements under normal conditions. Among them, the zoom lens is referred to as Z27.

[0185] The ray fan diagram is one of the evaluation methods commonly used by optical designers. Figure 5 for Figure 1 The light fan diagram of the zoom lens at infinite object distance at the wide-angle end is provided. Figure 6 for Figure 2 The provided zoom lens has a ray fan diagram at the infinite object distance at the telephoto end, where the image plane unit is millimeter / mm. Figure 5 and Figure 6 , the horizontal axis in a single figure is the normalized beam aperture, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 5 , Figure 6 It can be seen that the wavelengths of this zoom lens at different focal lengths and fields of view are all close to the horizontal axis, indicating that the vertical axis aberration of each wavelength is well corrected. In addition, the curves of each color are not obviously scattered, indicating that this zoom lens also has good correction of chromatic aberration, meeting the use requirements of this zoom lens.

[0186] Among them, the zoom lens is referred to as Z27.

[0187] Figure 7 for Figure 1The field curvature distortion curve of the zoom lens at infinite object distance at the wide-angle end is provided. Figure 8 for Figure 2 The provided zoom lens has a field curvature distortion curve at the infinite object distance at the telephoto end. Figure 7 and Figure 8 In the left coordinate system of the two figures, the horizontal coordinate represents the field curvature of the zoom lens, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, and S represents arc loss. Figure 7 and Figure 8 It can be seen that the lens provided in the first embodiment is effectively controlled in terms of field curvature from light with a wavelength of 436 nm to light with a wavelength of 656 nm, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small. Figure 7 and Figure 8 In the right coordinate system, the horizontal coordinate represents the size of the distortion, in %, and the vertical coordinate represents the normalized image height, in no unit. Figure 7 and Figure 8 It can be seen that the distortion of the lens provided in the first embodiment is well corrected, the imaging distortion is small, and the use requirements of the zoom lens are met.

[0188] Fig. 9 for Figure 1 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Fig.10 for Figure 2 The axial aberration curve of the zoom lens at infinite object distance at the telephoto end is provided. Fig. 9 and Fig.10 , the vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum pupil radius; the main wavelength uses 546.074nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Fig. 9 , Fig.10 It can be seen that the axial aberrations of normalized apertures at different wavelengths of 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens at different focal lengths is well controlled and meets the usage requirements.

[0189] Embodiment 2

[0190] Fig.11 This is a schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 2 of the present application. Fig.12 This is a schematic diagram of the structure of the zoom lens at the telephoto end provided in the second embodiment of the present application. Fig.11 and Fig.12A zoom lens provided in Embodiment 2 of the present application includes a first fixed lens group G1 with positive optical focal length, a variator lens group G2 with negative optical focal length, an aperture STO, a second fixed lens group G3 with positive optical focal length, a focus lens group G4 with positive optical focal length, and a third fixed lens group G5 with positive optical focal length, which are arranged in sequence from the object plane to the image plane along the optical axis; the first fixed lens group G1 and the second fixed lens group G3 are fixed, and the variator lens group G2 and the focus lens group G4 move along the optical axis when zooming.

[0191] Along the optical axis from the object plane to the image plane:

[0192] The first fixed lens group G1 includes a first lens L1 with negative optical power, a second lens L2 with positive optical power, and a third lens L3 with positive optical power. The first lens L1 and the second lens L2 are combined into a doublet lens.

[0193] The zoom lens group G2 includes a fourth lens L4 with negative optical power, a fifth lens L5 with negative optical power, a sixth lens L6 with positive optical power, and a seventh lens L7 with negative optical power. The fifth lens L5 and the sixth lens L6 are combined into a doublet lens.

[0194] The second fixed lens group G3 includes an eighth lens L8 with positive optical power, a ninth lens L9 with negative optical power, a tenth lens L10 with positive optical power and an eleventh lens L11 with negative optical power; the eighth lens L8 is an aspherical lens, and the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are combined into a triplet lens.

[0195] The focusing lens group G4 includes a twelfth lens L12 with positive optical power, a thirteenth lens L13 with negative optical power, a fourteenth lens L14 with positive optical power and a fifteenth lens L15 with negative optical power; the twelfth lens L12 is an aspherical lens, and the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 are combined into a triplet lens.

[0196] The third fixed lens group G5 includes a sixteenth lens L16 with positive refractive power and a seventeenth lens L17 with negative refractive power; the seventeenth lens L17 is an aspherical lens,

[0197] The zoom lens has a consistent aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, satisfying the following conditions: FNO≤1.50.

[0198] Wherein, FNO is the aperture number of the zoom lens at the full focal length.

[0199] Among them, the plane glass CG is located on the image side of the seventeenth lens L17. The plane glass CG can protect the photosensitive chip in the imaging sensor. The imaging chip is used to convert the optical signal collected by the zoom lens into an electrical signal, thereby ensuring the imaging effect of the zoom lens.

[0200] For example, Table 5 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 2 of the present application in a feasible implementation manner. The zoom lens in Table 5 corresponds to Fig.11 and Fig.12 Zoom lens shown.

[0201] Table 5 Design values ​​of optical physical parameters of zoom lens

[0202]

[0203]

[0204] Among them, the surface number S in Table 5 is numbered according to the order of the surfaces of each lens; "STO" represents the aperture STO of the zoom lens; IMA represents the image plane; the radius of curvature R represents the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; "INF" represents that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the refractive index nd represents the ability of the material between the current surface and the next surface to deflect light, and the space represents that the current position is air with a refractive index of 1. The Abbe number vd represents the dispersion characteristics of the material between the current surface and the next surface to the light; the semi-aperture represents half of the lens aperture. Among them, the more severe the medium dispersion, the smaller the Abbe number; conversely, the milder the medium dispersion, the larger the Abbe number.

[0205] Table 6 shows the values ​​of the zoom intervals of the zoom lens at the wide-angle end and the telephoto end in Table 5, in millimeters (mm).

[0206] Table 6 Design values ​​of variable pitch of zoom lens

[0207] Wide angle Telephoto end Zoom interval 1 0.4 34.729 Zoom interval 2 35.029 0.7 Zoom interval 3 8.882 6.311 Zoom interval 4 2.751 5.3216

[0208] The zoom intervals in Table 6 are different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0209] Combination Fig.11 and Fig.12 As shown in Table 5 and Table 6, by adjusting the distances of the lens zoom interval 1, zoom interval 2, zoom interval 3, and zoom interval 4 at the wide-angle end and the telephoto end respectively, the zoom ratio of the zoom lens can be changed to have a larger zoom ratio.

[0210] In this embodiment, the aspherical lens of the zoom lens may satisfy the following formula:

[0211]

[0212] Where Z is the axial distance from the curved surface at a position perpendicular to the optical axis at a height r to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; a4, a6, a8, a10, a12, a14, a16 are the high-order aspheric coefficients of the corresponding aspheric surface of the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order, a i r i The combination becomes the high-order terms corresponding to the aspheric surface, i = 4, 6, 8, 10, 12, 14, 16.

[0213] Exemplarily, Table 7 describes in detail the aspheric coefficients of each lens in Example 2 of the present application in a feasible implementation manner.

[0214] Table 7 Design values ​​of aspheric coefficients of each lens in zoom lens

[0215] Surface number k a4 a6 a8 14 0.555 -1.768208168363E-05 1.017571048213E-08 -6.202529812271E-10 15 45.961 9.042082197278E-07 5.577379604032E-08 -3.626724262512E-10 20 -2.203 1.055704206853E-05 2.540063763203E-08 -1.353507054133E-10 21 3.516 2.684234110992E-05 3.406944551901E-08 6.624141526764E-12 28 29.795 -2.833882734614E-04 4.106063405008E-06 -7.212336125714E-08 29 14.879 -3.632742381739E-04 3.788374696975E-06 -9.653956726225E-08

[0216] Surface number a10 a12 a14 a16 12 7.741839825492E-12 -4.127235253121E-14 3.812995309501E-19 5.634257620833E-20 13 5.620709589817E-12 -3.409474476497E-14 5.556735886466E-18 2.548651609018E-20 15 1.354759041673E-12 -4.765392813833E-16 -4.058960272605E-18 -4.238846778900E-20 16 1.425985150288E-12 4.746165197739E-17 -4.942623801841E-18 -4.532410445375E-20 25 9.706360453102E-10 -6.971483134211E-12 -7.318505641520E-15 1.538306867706E-16 26 1.399458642426E-09 -1.197307376222E-11 3.929977578747E-15 5.369187470016E-19

[0217] Among them, -1.768208168363E-05 means that the coefficient a4 of the surface number S14 is -1.768208168363*10-5, and so on.

[0218] As shown in Table 8, the zoom lens of the second embodiment achieves the following technical indicators:

[0219] Table 8 Technical specifications of zoom lenses

[0220]

[0221]

[0222] Furthermore, the performance parameters of the zoom lens provided in Example 2 were tested, and the test results are as follows:

[0223] Fig.13 for Fig.11 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Fig.14 for Fig.12 The vertical axis chromatic aberration curve of the zoom lens provided is at infinite object distance at the telephoto end. Fig.13 and Fig.14, the vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum image height; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Fig.13 , Fig.14 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a small range, indicating that the vertical chromatic aberration of the zoom lens at different focal lengths is well controlled and can meet the application requirements under normal conditions.

[0224] Fig.15 for Fig.11 The light fan diagram of the zoom lens at infinite object distance at the wide-angle end is provided. Fig.16 for Fig.12 The provided zoom lens has a ray fan diagram at infinite object distance at the telephoto end. Fig.15 and Fig.16 , the horizontal axis in a single figure is the normalized beam aperture, and the vertical axis is the vertical axis aberration. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Fig.15 , Fig.16 It can be seen that the wavelengths of this zoom lens at different focal lengths and fields of view are all close to the horizontal axis, indicating that the vertical axis aberration of each wavelength is well corrected. In addition, the curves of each color are not obviously scattered, indicating that this zoom lens also has good correction of chromatic aberration, meeting the use requirements of this zoom lens.

[0225] Fig.17 for Fig.11 The field curvature distortion curve of the zoom lens at infinite object distance at the wide-angle end is provided. Fig.18 for Fig.12 The provided zoom lens has a field curvature distortion curve at the infinite object distance at the telephoto end. Fig.17 and Fig.18 In the coordinate system on the left side of the two figures, the horizontal coordinate represents the field curvature of the zoom lens, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss; Fig.17 and Fig.18 It can be seen that the lens provided in this embodiment is effectively controlled in field curvature from light with a wavelength of 436nm to light with a wavelength of 656nm, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, in units of %; the vertical coordinate represents the normalized image height, without units; Fig.17 and Fig.18It can be seen that the distortion of the lens provided in this embodiment is well corrected, the imaging distortion is small, and the use requirements of the zoom lens are met.

[0226] Fig.19 for Fig.11 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Fig. 20 for Fig.12 The axial aberration curve of the zoom lens at infinite object distance at the telephoto end is provided. Fig.19 and Fig. 20 , the vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum pupil radius; the main wavelength uses 546.074nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Fig.19 , 20 It can be seen that the axial aberrations of normalized apertures at different wavelengths of 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens at different focal lengths is well controlled and meets the usage requirements.

[0227] Embodiment 3

[0228] Fig.21 This is a schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 3 of the present application. Fig. 22 This is a schematic diagram of the structure of the zoom lens at the telephoto end provided in the third embodiment of the present application. Fig.21 and Fig. 22 A zoom lens provided in Example 3 of the present application includes a first fixed lens group G1 with positive optical focal length, a variator lens group G2 with negative optical focal length, an aperture STO, a second fixed lens group G3 with positive optical focal length, a focus lens group G4 with positive optical focal length, and a third fixed lens group G5 with positive optical focal length, which are arranged in sequence from the object plane to the image plane along the optical axis; the first fixed lens group G1 and the second fixed lens group G3 are fixed, and the variator lens group G2 and the focus lens group G4 move along the optical axis when zooming.

[0229] Along the optical axis from the object plane to the image plane:

[0230] The first fixed lens group G1 includes a first lens L1 with negative optical power, a second lens L2 with positive optical power, and a third lens L3 with positive optical power. The first lens L1 and the second lens L2 are combined into a doublet lens.

[0231] The zoom lens group G2 includes a fourth lens L4 with negative optical power, a fifth lens L5 with negative optical power, a sixth lens L6 with positive optical power, and a seventh lens L7 with negative optical power. The fifth lens L5 and the sixth lens L6 are combined into a doublet lens.

[0232] The second fixed lens group G3 includes an eighth lens L8 with positive optical power, a ninth lens L9 with negative optical power, a tenth lens L10 with positive optical power and an eleventh lens L11 with negative optical power; the eighth lens L8 is an aspherical lens, and the ninth lens L9, the tenth lens L10 and the eleventh lens L11 are combined into a triplet lens.

[0233] The focusing lens group G4 includes a twelfth lens L12 with positive optical power, a thirteenth lens L13 with negative optical power, a fourteenth lens L14 with positive optical power and a fifteenth lens L15 with negative optical power; the twelfth lens L12 is an aspherical lens, and the thirteenth lens L13, the fourteenth lens L14 and the fifteenth lens L15 are combined into a triplet lens.

[0234] The third fixed lens group G5 includes a sixteenth lens L16 with positive refractive power and a seventeenth lens L17 with negative refractive power; the seventeenth lens L17 is an aspherical lens,

[0235] The zoom lens has a consistent aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, satisfying the following conditions: FNO≤1.50.

[0236] Wherein, FNO is the aperture number of the zoom lens at the full focal length.

[0237] For example, Table 9 describes in detail the specific optical and physical parameters of each lens in the zoom lens provided in Example 3 of the present application in a feasible implementation manner. The zoom lens in Table 9 corresponds to Fig.21 and Fig. 22 Zoom lens shown.

[0238] Table 9 Design values ​​of optical physical parameters of zoom lens

[0239] Surface number Surface type Radius of curvature thickness Materials (n.d.) Material (vd) 1 Spherical 150.236 0.648 1.95 32.2 2 Spherical 59.565 6.693 1.70 54.6 3 Spherical -659.711 0.040 4 Spherical 50.038 6.513 1.44 94.1 5 Spherical 558.518 Zoom interval 1 6 Spherical 90.487 0.662 1.80 45.3 7 Spherical 21.785 5.561 8 Spherical -68.722 0.503 1.50 81.6 9 Spherical 25.797 3.319 1.96 32.0 10 Spherical 258.782 2.580 11 Spherical -33.842 0.526 1.50 81.6 12 Spherical -1503.869 Zoom interval 2 STO Spherical INF 0.282 14 Aspheric 24.761 4.568 1.44 95.2 15 Aspheric -114.419 1.220 16 Spherical -43.633 0.668 1.52 57.8 17 Spherical 21.985 0.053 18 Spherical 21.847 7.957 1.50 80.4 19 Spherical -13.627 0.603 1.49 69.9 20 Spherical INF Zoom interval 3 21 Aspheric 20.894 6.447 1.50 81.6 22 Aspheric -32.607 0.076 23 Spherical 17.729 0.646 1.61 42.4 24 Spherical 10.646 7.768 1.50 81.6 25 Spherical -15.545 0.580 1.52 64.3 26 Spherical 11.676 Zoom interval 4 27 Spherical 69.403 2.159 1.73 54.7 28 Spherical -29.931 1.099 29 Aspheric -54.865 1.909 1.73 40.5 30 Aspheric 33.945 0.318 31 Spherical INF 1.500 1.52 58.57 32 Spherical INF 7.500 IMA Spherical INF -

[0240] Among them, the surface number S in Table 9 is numbered according to the order of the surfaces of each lens; "STO" represents the aperture STO of the zoom lens; IMA represents the image plane; the radius of curvature R represents the curvature of the lens surface, a positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side; "INF" represents that the surface is a plane and the radius of curvature is infinite; the thickness represents the central axial distance from the current surface to the next surface; the refractive index nd represents the ability of the material between the current surface and the next surface to deflect light, and the space represents that the current position is air with a refractive index of 1. The Abbe number vd represents the dispersion characteristics of the material between the current surface and the next surface to the light; the half-aperture represents half of the lens aperture. Among them, the more severe the medium dispersion, the smaller the Abbe number; conversely, the milder the medium dispersion, the larger the Abbe number.

[0241] Table 10 shows the values ​​of the zoom intervals of the zoom lens at the wide-angle end and the telephoto end in Table 9, in millimeters (mm).

[0242] Table 10 Design values ​​of variable pitch of zoom lens

[0243] Wide angle Telephoto end Zoom interval 1 0.371 34.621 Zoom interval 2 35.449 1.199 Zoom interval 3 8.689 6.309 Zoom interval 4 3.141 5.521

[0244] Among them, the zoom intervals in Table 9 are the different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0245] Combination Fig.21 and Fig. 22 As shown in Table 9 and Table 10, by adjusting the distances of the lens zoom interval 1, zoom interval 2, zoom interval 3, and zoom interval 4 at the wide-angle end and the telephoto end respectively, the zoom ratio of the zoom lens is changed to have a larger zoom ratio.

[0246] In this embodiment, the aspherical lens of the zoom lens may satisfy the following formula:

[0247]

[0248] Where Z is the axial distance from the curved surface at a position perpendicular to the optical axis at a height r to the vertex of the surface along the optical axis; c represents the curvature at the vertex of the aspheric surface; a4, a6, a8, a10, a12, a14, a16 are the high-order aspheric coefficients of the corresponding aspheric surface of the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth order, a i r i The combination becomes the high-order terms corresponding to the aspheric surface, i = 4, 6, 8, 10, 12, 14, 16.

[0249] Exemplarily, Table 11 describes in detail the aspheric coefficients of each lens in Example 3 of the present application in a feasible implementation manner.

[0250] Table 11 Design values ​​of aspheric coefficients of each lens in zoom lens

[0251] Surface number k a4 a6 a8 14 0.494 -1.870335117223E-05 8.840994780998E-09 -6.260403212035E-10 15 41.017 1.146715309539E-06 6.009923327607E-08 -3.570473001017E-10 21 -2.187 1.066022696967E-05 2.346631141698E-08 -1.473200116125E-10 22 3.543 2.709019540532E-05 3.629477034481E-08 2.732517560877E-11 29 31.193 -2.834778436275E-04 4.149565899995E-06 -7.209552779746E-08 30 15.130 -3.642013863061E-04 3.882727763974E-06 -9.506315393579E-08

[0252] Surface number a10 a12 a14 a16 14 7.979713860547E-12 -4.091297972540E-14 2.137823114960E-18 -8.216171006851E-21 15 5.883617835465E-12 -3.488161570218E-14 1.173070880796E-18 3.219632738497E-20 21 1.303417990268E-12 -2.599595727660E-16 -2.590503947279E-18 -5.536185403671E-21 22 1.467175738914E-12 3.714898203396E-17 -4.778172856025E-19 -2.514975164284E-20 29 9.790546050650E-10 -6.745411084069E-12 1.333270093752E-16 2.608366762089E-17 30 1.386625901408E-09 -1.158803438412E-11 4.227074390935E-15 5.444752302605E-19

[0253] Among them, -1.870335117223E-05 means that the coefficient a4 of the surface number S14 is -1.870335117223*10 -5 , and so on.

[0254] As shown in Table 12, the zoom lens of the third embodiment achieves the following technical indicators:

[0255] Table 12 Technical specifications of zoom lenses

[0256] Wide angle Telephoto end Image size(mm) Φ13.10 Φ13.10 Focal length(mm) 15 50.261 Wavelength(nm) 436～850 436～850 Total optical length (mm) 120 120

[0257] Furthermore, the performance parameters of the zoom lens provided in Example 3 were tested, and the test results are as follows:

[0258] Fig.23 for Fig.21 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Fig.24 for Fig. 22 The vertical axis chromatic aberration curve of the zoom lens provided is at infinite object distance at the telephoto end. Fig.23 and Fig.24 , the vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum image height; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Fig.23 , Fig.24 It can be seen that the vertical chromatic aberration of different wavelengths is controlled within a small range, indicating that the vertical chromatic aberration of the zoom lens at different focal lengths is well controlled and can meet the application requirements under normal conditions.

[0259] Fig.25 for Fig.21 The light fan diagram of the zoom lens at infinite object distance at the wide-angle end is provided. Fig.26 for Fig. 22 The provided zoom lens has a ray fan diagram at infinite object distance at the telephoto end. Fig.25 and Fig.26 In a single figure, the horizontal axis is the normalized beam aperture, and the vertical axis is the vertical axis aberration, where the image plane unit is millimeter / mm. Ideally, each curve should completely coincide with the horizontal axis, and all light rays in the field of view are focused on the same point on the image plane; the vertical axis in a single image can also be expressed as the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Fig.25 , Fig.26 It can be seen that the wavelengths of this zoom lens at different focal lengths and fields of view are all close to the horizontal axis, indicating that the vertical axis aberration of each wavelength is well corrected. In addition, the curves of each color are not obviously scattered, indicating that this zoom lens also has good correction of chromatic aberration, meeting the use requirements of this zoom lens.

[0260] Fig. 27 for Fig.21 The field curvature distortion curve of the zoom lens at infinite object distance at the wide-angle end is provided. Fig.28 for Fig. 22 The provided zoom lens has a field curvature distortion curve at the infinite object distance at the telephoto end. Fig. 27 and Fig.28In the coordinate system on the left side of the two figures, the horizontal coordinate represents the field curvature of the zoom lens, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents arc loss; Fig. 27 and Fig.28 It can be seen that the lens provided in this embodiment is effectively controlled in field curvature from light with a wavelength of 436nm to light with a wavelength of 656nm, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, in units of %; the vertical coordinate represents the normalized image height, without units; Fig. 27 and Fig.28 It can be seen that the distortion of the lens provided in this embodiment is well corrected, the imaging distortion is small, and the use requirements of the zoom lens are met.

[0261] Fig.29 for Fig.21 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Fig.30 for Fig. 22 The axial aberration curve of the zoom lens at infinite object distance at the telephoto end is provided. Fig.29 and Fig.30 , the vertical direction represents the normalized aperture, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum pupil radius; the main wavelength uses 546.074nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Fig.29 and Fig.30 It can be seen that the axial aberrations of normalized apertures of different wavelengths from 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of the zoom lens at different focal lengths is well controlled and meets the usage requirements.

[0262] In summary, in Embodiment 1, Embodiment 2 and Embodiment 3 of the present application, the optical physical parameters of the first lens to the seventeenth lens are as shown in Table 13.

[0263] Table 13 Design values ​​of optical physical parameters of zoom lens

[0264]

[0265]

[0266] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A zoom lens, characterized in that: The lens comprises a first fixed lens group with positive focal power, a variable-power lens group with negative focal power, an aperture, a second fixed lens group with positive focal power, a focusing lens group with positive focal power, and a third fixed lens group with positive focal power, which are arranged in sequence along the optical axis from the object plane to the image plane; the first fixed lens group and the second fixed lens group are fixed, and the variable-power lens group and the focusing lens group move along the optical axis when zooming; Along the optical axis from the object plane to the image plane: The first fixed lens group includes a first lens with negative optical power, a second lens with positive optical power, and a third lens with positive optical power; The variable power lens group includes a fourth lens with negative optical power, a fifth lens with negative optical power, a sixth lens with positive optical power and a seventh lens with negative optical power; The second fixed lens group includes an eighth lens with positive optical power, a ninth lens with negative optical power, a tenth lens with positive optical power and an eleventh lens with negative optical power; the eighth lens is an aspherical lens; the second fixed lens group includes at least one aspherical lens; The focusing lens group includes a twelfth lens with positive optical power, a thirteenth lens with negative optical power, a fourteenth lens with positive optical power and a fifteenth lens with negative optical power; the focusing lens group includes at least one aspherical lens; The third fixed lens group includes a sixteenth lens with positive optical power and a seventeenth lens with negative optical power; the third fixed lens group includes at least one aspherical lens; The zoom lens has a consistent aperture position relative to the image plane position at different focal lengths, and the aperture diameter is the same at different focal lengths, satisfying the following conditions: FNO≤1.50; Wherein, FNO is the aperture number of the zoom lens at the full focal length.

2. The zoom lens according to claim 1, wherein: Along the direction from the object side to the image side of the optical axis, the surface shape of each lens is: The surface shape of the first lens is convex-concave; the surface shape of the second lens is convex-convex; the surface shape of the third lens is convex-concave; The surface shape of the fourth lens is convex-concave, the surface shape of the fifth lens is concave-concave, the surface shape of the sixth lens is convex-concave, and the surface shape of the seventh lens is concave-convex or concave-flat; The surface shape of the eighth lens is convex-convex, the surface shape of the ninth lens is concave-concave, the surface shape of the tenth lens is convex-convex; the surface shape of the eleventh lens is concave-flat; The surface shape of the twelfth lens is convex-convex; the surface shape of the thirteenth lens is convex-concave; the surface shape of the fourteenth lens is convex-convex, and the surface shape of the fifteenth lens is concave-concave; The surface shape of the sixteenth lens is a convex-convex surface, and the surface shape of the seventeenth lens is a concave-concave surface.

3. The zoom lens according to claim 1, wherein: The focal lengths of the lens groups of the zoom lens and the focal length of the lens at the wide-angle end satisfy the following relationship: 6.050≤F1 / FW≤6.243;-1.800≤F2 / FW≤-1.765; 5.307≤F3 / FW≤6.284;1.879≤F4 / FW≤2.025;18.214≤F5 / FW≤33.289; Among them, F1, F2, F3, F4, and F5 are the focal lengths of the first fixed lens group, the variable power lens group, the second fixed lens group, the focusing lens group, and the third fixed lens group respectively; and FW is the focal length of the wide-angle end of the zoom lens.

4. The zoom lens according to claim 1, wherein: The eighth lens is an aspherical lens; the twelfth lens is an aspherical lens; and the seventeenth lens is an aspherical lens.

5. The zoom lens according to claim 4, wherein: The materials of the eighth lens, the twelfth lens and the seventeenth lens meet the following requirements: 1.44≤nd8≤1.50;81.5≤vd8≤95.2; 1.50≤nd12≤1.53;70.32≤vd12≤81.5; 1.69≤nd17≤1.73;31.1≤vd17≤40.5; Among them, nd8, nd12, and nd17 are the refractive indices of the eighth lens, the twelfth lens, and the seventeenth lens respectively, and vd8, vd12, and vd17 are the Abbe numbers of the eighth lens, the twelfth lens, and the seventeenth lens respectively.

6. The zoom lens according to claim 1, wherein: The first fixed lens group includes at least one cemented lens; The variable power lens group includes at least one cemented lens; The three lenses close to the image plane in the second fixed lens group form a triplet lens; or form a single lens and a doublet lens; The three lenses close to the image plane in the focusing lens group form a triplet lens; or form a single lens and a doublet lens.

7. The zoom lens according to claim 6, wherein: The triplet lens composed of the ninth lens, the tenth lens and the eleventh lens satisfies: -1.018≤F9-10-11 / FG3≤-0.897; Among them, F9-10-11 represents the focal length of the combination of the ninth lens, the tenth lens and the eleventh lens, and FG3 represents the focal length of the second fixed lens group.

8. The zoom lens according to claim 6, wherein: The thirteenth lens, the fourteenth lens and the fifteenth lens are combined into a triplet lens, which satisfies: -2.337≤F13-14-15 / FG4≤-1.946; Among them, F13-14-15 represents the focal length of the combination of the thirteenth lens, the fourteenth lens and the fifteenth lens, and FG4 represents the focal length of the focusing lens group.

9. The zoom lens according to claim 1, wherein: The variable power lens group and the focus lens group satisfy the following relationship: 13.296≤S2 / S4≤14.391; Among them, S2 is the maximum distance that the zoom lens group moves along the optical axis direction, and S4 is the maximum distance that the focus lens group moves along the optical axis direction.

10. The zoom lens according to claim 1, wherein: The total length of the zoom lens and the moving distance of the zoom lens group satisfy the following relationship: 3.454≤TTL / S2≤3.504; Wherein, TTL is the total length of the zoom lens, and S2 is the maximum distance that the zoom lens group moves along the optical axis.

Images