A zoom lens

Abstract

The present invention discloses a zoom lens, comprising a first fixed lens group, a variator lens group, an aperture, a second fixed lens group, a focus lens group, and a third fixed lens group, arranged in sequence along the optical axis from the object plane to the image plane, with the focal powers being positive, negative, positive, positive, and positive, respectively. The first fixed lens group consists of three lenses, with the focal powers being negative, positive, and positive, respectively. The variator lens group consists of four lenses, with the focal powers being negative, negative, positive, and negative, respectively. The second fixed lens group consists of four lenses, with the focal powers being positive, negative, positive, and negative, respectively. The focus lens group consists of four lenses, with the focal powers being positive, negative, positive, and negative, respectively. The third fixed lens group consists of two lenses, with the focal powers being positive and negative, respectively. The zoom lens can achieve the requirements of large aperture and clear imaging on a 1 / 1.2″ target surface and in the 436nm-850nm wavelength band.

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) lenses are specifically designed for image sensors. Currently, most ITS lenses commonly used on the market are fixed-focus lenses, with low image quality and poor tolerance to harsh environments. Faced with increasingly complex operating environments, zoom lenses are becoming increasingly popular in the ITS field. However, the variety of zoom lenses available for ITS applications is extremely limited, and they suffer from issues such as low image quality, a narrow focal length range, and a limited temperature range, making them difficult to implement in practice.

[0003] Therefore, it is particularly necessary to develop a zoom lens with large aperture, high resolution, 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 achieve the requirements of large aperture and clear imaging in a 1 / 1.2″ target area and a 405nm-656nm wavelength band.

[0005] The present invention provides a zoom lens, comprising a first fixed lens group with positive optical power, a variator lens group with negative optical power, an aperture stop, 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, arranged in sequence along an optical axis from an object plane to an image plane. The first fixed lens group and the second fixed lens group are fixed, while the variator lens group and the focus lens group move along the optical axis during 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 zoom lens assembly includes a fourth lens having negative optical power, a fifth lens having negative optical power, a sixth lens having positive optical power, and a seventh lens having 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; and 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 maintains a consistent diaphragm position relative to the image plane at different focal lengths, and has the same diaphragm diameter 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 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:

[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 zoom 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 zoom lens at the wide-angle end.

[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; 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] Wherein, 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, which satisfies:

[0038] -2.337≤F13-14-15 / FG4≤-1.946;

[0039] Wherein, 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 zoom lens group and the focus 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, and S4 is the maximum distance that the focus lens group moves along the optical axis.

[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 an embodiment of the present application includes a first fixed lens group, a variator 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 consists of three lenses, and the optical focal powers are negative, positive, and positive, respectively; the variator lens group consists of four lenses, and the optical focal powers are negative, negative, positive, and negative, respectively; the second fixed lens group consists of four lenses, and the optical focal powers are positive, negative, positive, and negative, respectively; the focusing lens group consists of four lenses, and the optical focal powers are positive, negative, positive, and negative, respectively; and the third fixed lens group consists of two lenses, and the optical focal powers are positive and negative, respectively. This 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 Example 1 of the present application;

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

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

[0049] Figure 4 for Figure 2 Provided is the vertical axis chromatic aberration curve of the zoom lens 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 Provided is the field curvature distortion curve of the zoom lens at infinite object distance at the wide-angle end;

[0053] Figure 8 for Figure 2 Provided is the field curvature distortion curve of the zoom lens at the infinite object distance at the telephoto end;

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

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

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

[0057] Figure 12 A schematic diagram of the structure of the zoom lens at the telephoto end provided in Example 2 of the present application;

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

[0059] Figure 14 for Figure 12 Provided is the vertical axis chromatic aberration curve of the zoom lens at infinite object distance at the telephoto end;

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

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

[0062] Figure 17 for Figure 11 Provided is the field curvature distortion curve of the zoom lens at infinite object distance at the wide-angle end;

[0063] Figure 18 for Figure 12 Provided is the field curvature distortion curve of the zoom lens at the infinite object distance at the telephoto end;

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

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

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

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

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

[0069] Figure 24 for Figure 22 Provided is the vertical axis chromatic aberration curve of the zoom lens at infinite object distance at the telephoto end;

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

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

[0072] Figure 27 for Figure 21 Provided is the field curvature distortion curve of the zoom lens at infinite object distance at the wide-angle end;

[0073] Figure 28 for Figure 22 Provided is the field curvature distortion curve of the zoom lens at the infinite object distance at the telephoto end;

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

[0075] Figure 30 for Figure 22 Provided are the axial aberration curves of the zoom lens at infinite object distance at the telephoto end. DETAILED DESCRIPTION

[0076] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present application and are not intended to limit the present application. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions of the present application, not all of the structures.

[0077] Figure 1 This is a schematic diagram of the structure of the zoom lens at the wide-angle end provided in Example 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 Example 1 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 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 during 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 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.

[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 maintains the same aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, meeting 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 magnification 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 (not shown in the figure). The first fixed lens group G1, the second fixed lens group G3 and the third fixed lens group G5 are fixed in position 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 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 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 in the process of zooming by moving the zoom lens group G2 and the focus lens group G4, when the focal length is shortest, the zoom lens is at the wide-angle end, and when the focal length is longest, the zoom lens is at the telephoto end. 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 of aspherical surfaces are not represented according to actual conditions.

[0089] Furthermore, the focal length 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 inverse of the focal length, and it characterizes the ability of the zoom lens to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. The focal length 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 the aperture stop and the field stop. The aperture stop refers to the stop that limits the light beam the most, and the field stop refers to the stop that limits the field of view (size) the most.

[0091] Reference Figure 1 and Figure 2 The front end of the iris STO uses a first fixed lens group G1 with positive focal length and a zoom lens group G2 with negative focal length. This ensures a larger light aperture after the light passes through, increasing the aperture number of the zoom lens to meet the needs of use under different conditions. The rear end of the iris STO uses a second fixed lens group G3 with positive focal length, a focusing lens group G4 with positive focal length, and a third fixed lens group G5 with positive focal length. By properly matching the focal lengths of the rear end lens groups, the aberrations at the rear end of the lens can be corrected. Combined with the lens at the front end of the iris STO, the imaging quality of the zoom lens can be stabilized.

[0092] Specifically, placing the aperture stop STO between the negative-power seventh lens element L7 and the positive-power eighth lens element L8 can regulate the propagation direction of the light beam emitted by the seventh lens element L7 to the incident surface of the eighth lens element 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 focusing lens group G4 on the optical axis, the zoom lens can be switched between the wide-angle and telephoto ends at will.

[0093] Furthermore, the diaphragm diameter of the diaphragm STO can be controlled to be the same at different focal lengths, and the aperture number FNO of the zoom lens at all focal lengths can be ≤1.50. This structurally reduces the aperture range, ensures a longer moving distance for the movable group of the lens, 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 distributes 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 zoom movement of the zoom lens group G2, thereby effectively achieving aberration balance in each focal length and ensuring the clarity of the image under different focal length states.

[0095] In 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 called the object side surface, and the surface of the lens adjacent to the image plane is called the image side surface. The surface shape of each lens refers to the concave and convex shapes of the object side surface and the image side surface along the optical axis. Specifically:

[0096] In the first fixed lens group G1 , the surface of the first lens L1 is convex-concave; the surface of the second lens L2 is convex-convex; and the surface 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 eighth lens L8 has a convex-convex surface, the ninth lens L9 has a concave-concave surface, the tenth lens L10 has a convex-convex surface, and the eleventh lens L11 has a concave-flat surface.

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

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

[0101] The concave lens has a diverging effect on the transmitted light, while 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 can be achieved at various focal lengths of the zoom lens.

[0102] Considering that aspherical lenses have a good ability to control high-level aberrations of the optical system, 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 all adopt aspherical lenses. When the light passes through the aperture STO, the use of aspherical lenses can well correct the aberration at the rear end of the aperture STO, avoiding the situation where the aberration is superimposed at the rear end of the lens, making it difficult to pull back the rear end, thereby stabilizing the imaging quality of the optical system through the cooperation of 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 surface at a height r perpendicular to the optical axis 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, and a16 are the high-order aspheric coefficients of the corresponding aspheric surface, namely, the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders. 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 may be a plastic aspheric lens, which can significantly reduce the cost of the zoom lens. Alternatively, one of the eighth lens L8, the twelfth lens L12, and the seventeenth lens L17 may be a glass spherical lens, or a mixture of a glass aspheric lens and a plastic aspheric lens. Glass and plastic, these two types of materials, can also compensate for each other and balance high and low temperatures, so that the zoom lens has stable high and low temperature performance, which helps 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, and this is not limited here. The material of the plastic aspheric 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. This embodiment of the application does not elaborate on this and does not limit this.

[0111] Based on the above embodiments, Figure 1-Figure 2 , each of the variator lens group G2, the second fixed lens group G3, and the third fixed lens group G5 includes 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] Wherein, 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 produce stable images at all 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 in optical systems, during the zoom process, this 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 properly 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 smooth emission of light from the front end, ensuring resolution and image height, and ensuring illumination while improving the imaging quality of the lens.

[0117] Furthermore, given the temperature insensitivity of glass lenses, lenses using all-glass lenses exhibit more uniform performance across different temperature regimes, offering stable high and low temperature performance, thereby enhancing the environmental adaptability of zoom lenses. In the embodiments of this application, the eighth lens L8, the twelfth lens L12, and the seventeenth lens L17 can also utilize glass aspherical lenses. This significantly corrects chromatic aberration and higher-order aberrations of the lenses, offering a wider range of structural options compared to plastic aspherical lenses, thereby enhancing the market competitiveness of the lenses. Furthermore, the glass spherical lenses can be made of various types of glass known to those skilled in the art, and will not be further elaborated in this embodiment of the application.

[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 doublet. This effectively reduces the air gap between the first lens L1 and the second lens L2, shortening the overall length of the zoom lens. The doublet has a convex-concave surface shape, which facilitates the smooth collection of object-side light into the imaging system and can significantly correct higher-order aberrations. This shape also allows for better collection of light at a wide field of view, ensuring wide-angle imaging requirements.

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

[0122] Furthermore, the fifth lens L5 and the sixth lens L6 in the zoom lens group G2 are combined into a doublet. In other embodiments, the fifth lens L5 and the sixth lens L6 can also be used as two single lenses. Specifically, the doublet of the fifth lens L5 and the sixth lens L6 in the zoom lens group G2 has a concave-concave surface, which effectively reduces the air gap between the fifth lens L5 and the sixth lens L6, thereby reducing the overall length of the zoom lens. When light is diverged by the negative optical power fifth lens L5, it enters the positive optical power sixth lens L6 for convergence, then enters the negative optical power seventh lens L7 for divergence, and then enters the positive optical power eighth lens L8 for convergence. This allows the light to be diffused and focused multiple times, allowing the light to pass smoothly through the middle of the lens. Before the light enters the second fixed lens group G3, the use of a doublet can reduce chromatic aberration and aberration generated at the front end, further improving image 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 the two cemented lenses can also correct the high-level 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] Furthermore, 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.

[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 ninth lens element L9, tenth lens element L10, and eleventh lens element L11 are combined into a cemented triplet lens, the focal lengths of the triplet and the second fixed lens group G3 are matched in the aforementioned manner. When light passes through aperture STO, the use of aspherical lenses effectively corrects aberrations in the front zoom lens group G2 during zooming, preventing aberrations from accumulating at the rear end of the lens, making it difficult to retract the lens. The cemented triplet lens further corrects higher-order aberrations and chromatic aberrations generated by the front end and the lens group itself, effectively improving image quality.

[0129] In some embodiments, the surface profile of the doublet of the tenth lens L10 and the eleventh lens L11 in the second fixed lens group G3 is convex-flat. Light rays are converged by the positive-power eighth lens L8, diffused by the negative-power ninth lens L9, and then converged by the positive-power tenth lens L10 before entering the negative-power eleventh lens L11 for diffusion. This allows the light rays to smoothly pass through the middle of the lens before entering the rear third fixed lens group G5. The use of a doublet can reduce the air gap between the tenth lens L10 and the eleventh lens L11, shortening the overall length of the zoom lens. This can also reduce chromatic aberration and aberration generated at the front end, further improving image quality.

[0130] Furthermore, 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. In other embodiments, the fourteenth lens L14 and the fifteenth lens L15 can also be combined into a doublet lens.

[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 cemented 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. The focal length of the triplet lens is matched with the focal length of the focusing lens group G4 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 profile of the cemented doublet lens formed by the fourteenth lens L14 and the fifteenth lens L15 is convex-concave, effectively reducing the air gap between the fourteenth lens L14 and the fifteenth lens L15, thereby shortening the overall length of the zoom lens. When light is converged by the positive-power fourteenth lens L14 and then diffused by the negative-power fifteenth lens L15 before entering the third fixed lens group G5, this facilitates aberration correction across the entire focal length, improving pixel imaging quality and 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 performance such as distortion, reduce light loss caused by reflection between lenses, increase illumination, thereby improving image quality and enhancing the clarity of lens imaging. In addition, bonding lenses can also reduce the number of assembly components between lenses, simplify the assembly procedures in the lens manufacturing process, reduce costs, and reduce the sensitivity of lens units to tolerances such as tilt / eccentricity caused by 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. F1, F2, F3, F4, and F5 are the focal lengths of the first fixed lens group G1, the variator 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 impact 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] Wherein, 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 entire 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 magnification 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, ensuring that the required imaging quality and variable magnification are met under the condition of a small lens volume.

[0147] refer to Figure 1-Figure 2 A thick flat glass CG is placed between the seventeenth lens element L17 and the image plane IMA. This provides protection and filters out unwanted stray light, improving the image quality of the zoom lens. For example, the flat glass CG improves the image quality of the zoom lens by filtering out infrared light during the day.

[0148] In summary, the zoom lens provided in the embodiments of the present application, through the rational combination of optical power, refractive index, and materials of the five lens groups, can effectively achieve aberration balance at each focal length, ensuring image clarity at different focal lengths, and achieving the 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 embodiments of this application, when used in an ITS lens, offers high resolution, low distortion, and high contrast, providing clear, accurate, and high-quality images. Its design takes into account optical properties, mechanical structure, and electronic interfaces, effectively adapting 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] Example 1

[0152] Continue to refer Figure 1-Figure 2 As shown, a zoom lens provided in Example 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 focusing 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 focusing lens group G4 move along the optical axis during 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 cemented triplet.

[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 form a cemented triplet.

[0158] 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 seventeenth lens L17 is an aspherical lens.

[0159] The zoom lens maintains the same aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, meeting 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 flat glass CG is located on the image-side surface of the seventeenth lens L17. The flat glass CG can protect the photosensitive chip in the imaging sensor. The imaging chip is used to convert the light 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] The surface number S in Table 1 is numbered according to the order of the lens surfaces; "STO" represents the aperture of a zoom lens; IMA represents the image plane; the radius of curvature R represents the degree of curvature of the lens surface; a positive value indicates that the surface is curved toward the image plane, and a negative value indicates that the surface is curved toward the object plane; "INF" indicates that the surface is flat and has an infinite radius of curvature; the thickness represents the central axial distance from the current surface to the next surface; the refractive index nd represents the light-bending ability of the material between the current and next surfaces; a blank space represents the current position as air with a refractive index of 1. The Abbe number vd represents the light-dispersion properties of the material between the current and next surfaces; and the half-aperture represents half the lens aperture. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less chromatic dispersion of the medium, the larger the Abbe number.

[0167] Furthermore, Table 2 shows the values ​​of the 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 end 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] Combine 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 surface at a height r perpendicular to the optical axis 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, and a16 are the high-order aspheric coefficients of the corresponding aspheric surface, namely, the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders. i r i The combination becomes the high-order terms corresponding to the aspheric surface, i = 4, 6, 8, 10, 12, 14, 16.

[0175] For example, 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 design value of the aspheric coefficient of the face-sequence mirror is S11, and the coefficient a4 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 end 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, the vertical axis vertex represents the maximum image height; the main wavelength is 546.07nm, the horizontal direction represents the offset relative to the main wavelength, the unit is micrometer (um). Figure 3 、 Figure 4 It can be seen that vertical chromatic aberration at different wavelengths is kept within a relatively small range, indicating that this zoom lens has well-controlled vertical chromatic aberration at different focal lengths, meeting the requirements of conventional applications. The zoom lens is referred to as the Z27.

[0185] The ray fan diagram is one of the evaluation methods commonly used by optical designers. Figure 5 for Figure 1 The provided zoom lens has a ray fan diagram at infinite object distance at the wide-angle end. Figure 6 for Figure 2 The provided zoom lens has a ray fan diagram at the telephoto end with infinite object distance, where the image plane unit is mm. Figure 5 and Figure 6 In a single figure, the horizontal axis is the normalized beam diameter, 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 As can be seen, the zoom lens's curves for each wavelength at all focal lengths and fields of view are all well aligned with the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color exhibit no significant dispersion, demonstrating that chromatic aberration is well corrected, meeting the requirements for this zoom lens.

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

[0187] Figure 7 for Figure 1The provided zoom lens has a field curvature distortion curve at infinite object distance at the wide-angle end. Figure 8 for Figure 2 The provided zoom lens has a field curvature distortion curve at the telephoto end with infinite object distance. 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 the meridian, and S represents the arc loss. Figure 7 and Figure 8 It can be seen that the lens provided in the first embodiment effectively controls the field curvature from light with a wavelength of 436 nm to light with a wavelength of 656 nm, that is, during 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, and the unit is %; the vertical coordinate represents the normalized image height, and there is 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] Figure 9 for Figure 1 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Figure 10 for Figure 2 The provided zoom lens has an axial aberration curve at infinite object distance at the telephoto end. Figure 9 and Figure 10 , the vertical direction represents the normalized aperture, 0 represents the optical axis, the vertical axis vertex 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). Figure 9 、 Figure 10 It can be seen that the axial aberrations at different wavelengths and normalized apertures of 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at different focal lengths is well controlled and meets usage requirements.

[0189] Example 2

[0190] Figure 11 This is a schematic diagram of the structure of the zoom lens at the wide-angle end provided in Example 2 of the present application. Figure 12 This is a schematic diagram of the structure of the zoom lens at the telephoto end provided in Example 2 of this application. Figure 11 and Figure 12A zoom lens provided in a second 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 stop 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 during 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 cemented triplet.

[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 form a cemented triplet.

[0196] 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 seventeenth lens L17 is an aspherical lens.

[0197] The zoom lens maintains the same aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, meeting 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 flat glass CG is located on the image-side surface of the seventeenth lens L17. The flat glass CG can protect the photosensitive chip in the imaging sensor. The imaging chip is used to convert the light 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 Figure 11 and Figure 12 Zoom lens shown.

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

[0202]

[0203]

[0204] The surface number S in Table 5 is numbered according to the order of the lens surfaces; "STO" represents the aperture stop STO of the zoom lens; IMA represents the image plane; the radius of curvature R represents the degree of curvature of the lens surface; a positive value indicates that the surface is curved toward the image plane, and a negative value indicates that the surface is curved toward the object plane; "INF" indicates that the surface is flat 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 light deflection ability of the material between the current and next surfaces; a blank space represents the current position as air with a refractive index of 1. The Abbe number vd represents the light dispersion characteristics of the material between the current and next surfaces; and the half-aperture represents half the lens aperture. The greater the dispersion of the medium, the smaller the Abbe number; conversely, the less dispersion the medium, 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 end 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 the different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0209] Combine Figure 11 and Figure 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 surface at a height r perpendicular to the optical axis 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, and a16 are the high-order aspheric coefficients of the corresponding aspheric surface, namely, the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders. i r i The combination becomes the high-order terms corresponding to the aspheric surface, i = 4, 6, 8, 10, 12, 14, 16.

[0213] For example, 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 the 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 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] Figure 13 for Figure 11 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Figure 14 for Figure 12 The vertical axis chromatic aberration curve of the zoom lens provided is at infinite object distance at the telephoto end. Figure 13 and Figure 14, the vertical direction represents the normalized aperture, 0 represents the optical axis, the vertical axis vertex represents the maximum image height; the main wavelength is 546.07nm, the horizontal direction represents the offset relative to the main wavelength, the unit is micrometer (um). Figure 13 、 Figure 14 It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a relatively small range, indicating that the vertical chromatic aberration of the zoom lens at different focal lengths is well controlled and can meet application requirements under normal conditions.

[0224] Figure 15 for Figure 11 The provided zoom lens has a ray fan diagram at infinite object distance at the wide-angle end. Figure 16 for Figure 12 The provided zoom lens has a ray fan diagram at the infinite object distance at the telephoto end. Figure 15 and Figure 16 In a single figure, the horizontal axis is the normalized beam diameter, 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 15 、 Figure 16 As can be seen, the zoom lens's curves for each wavelength at all focal lengths and fields of view are all well aligned with the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color exhibit no significant dispersion, demonstrating that chromatic aberration is well corrected, meeting the requirements for this zoom lens.

[0225] Figure 17 for Figure 11 The provided zoom lens has a field curvature distortion curve at infinite object distance at the wide-angle end. Figure 18 for Figure 12 The provided zoom lens has a field curvature distortion curve at the telephoto end with infinite object distance. Figure 17 and Figure 18 In the left coordinate system of the two figures, the horizontal coordinate represents the magnitude of the zoom lens field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents the meridian, S represents the arc loss; Figure 17 and Figure 18 It can be seen that the lens provided in this embodiment effectively controls field curvature from light with a wavelength of 436nm to light with a wavelength of 656nm. That is, when imaging, the difference in image quality between the center and the periphery is small. In the coordinate system on the right, the horizontal coordinate represents the degree of distortion in %, and the vertical coordinate represents the normalized image height in no unit. Figure 17 and Figure 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] Figure 19 for Figure 11 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Figure 20 for Figure 12 The provided zoom lens has an axial aberration curve at infinite object distance at the telephoto end. Figure 19 and Figure 20 , the vertical direction represents the normalized aperture, 0 represents the optical axis, the vertical axis vertex 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). Figure 19 、 20 It can be seen that the axial aberrations at different wavelengths and normalized apertures of 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at different focal lengths is well controlled and meets usage requirements.

[0227] Example 3

[0228] Figure 21 This is a schematic diagram of the structure of the zoom lens at the wide-angle end provided in Example 3 of the present application. Figure 22 This is a schematic diagram of the structure of the zoom lens at the telephoto end provided in Example 3 of this application. Figure 21 and Figure 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 stop 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 during 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 cemented triplet.

[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 form a cemented triplet.

[0234] 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 seventeenth lens L17 is an aspherical lens.

[0235] The zoom lens maintains the same aperture position relative to the image plane at different focal lengths, and the aperture diameter is the same at different focal lengths, meeting 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 Figure 21 and Figure 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 (nd) Material (vd) 1 spherical surface 150.236 0.648 1.95 32.2 2 spherical surface 59.565 6.693 1.70 54.6 3 spherical surface -659.711 0.040 4 spherical surface 50.038 6.513 1.44 94.1 5 spherical surface 558.518 Zoom interval 1 6 spherical surface 90.487 0.662 1.80 45.3 7 spherical surface 21.785 5.561 8 spherical surface -68.722 0.503 1.50 81.6 9 spherical surface 25.797 3.319 1.96 32.0 10 spherical surface 258.782 2.580 11 spherical surface -33.842 0.526 1.50 81.6 12 spherical surface -1503.869 Zoom interval 2 STO spherical surface INF 0.282 14 Aspheric 24.761 4.568 1.44 95.2 15 Aspheric -114.419 1.220 16 spherical surface -43.633 0.668 1.52 57.8 17 spherical surface 21.985 0.053 18 spherical surface 21.847 7.957 1.50 80.4 19 spherical surface -13.627 0.603 1.49 69.9 20 spherical surface INF Zoom interval 3 21 Aspheric 20.894 6.447 1.50 81.6 22 Aspheric -32.607 0.076 23 spherical surface 17.729 0.646 1.61 42.4 24 spherical surface 10.646 7.768 1.50 81.6 25 spherical surface -15.545 0.580 1.52 64.3 26 spherical surface 11.676 Zoom interval 4 27 spherical surface 69.403 2.159 1.73 54.7 28 spherical surface -29.931 1.099 29 Aspheric -54.865 1.909 1.73 40.5 30 Aspheric 33.945 0.318 31 spherical surface INF 1.500 1.52 58.57 32 spherical surface INF 7.500 IMA spherical surface INF -

[0240] The surface number S in Table 9 is numbered according to the order of the lens surfaces; "STO" represents the aperture stop STO of the zoom lens; IMA represents the image plane; the radius of curvature R represents the degree of curvature of the lens surface; a positive value indicates that the surface is curved toward the image plane, and a negative value indicates that the surface is curved toward the object plane; "INF" indicates that the surface is flat 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 light-bending ability of the material between the current and next surfaces; a blank space represents the current position as air with a refractive index of 1. The Abbe number vd represents the light-dispersion properties of the material between the current and next surfaces; and the half-aperture represents half the lens aperture. The more severe the dispersion of the medium, the smaller the Abbe number; conversely, the less chromatic dispersion of the medium, the larger the Abbe number.

[0241] Table 10 shows the values ​​of the zoom intervals of the zoom lenses 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 end 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] 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] Combine Figure 21 and Figure 22 As shown in Tables 9 and 10, by adjusting the distances of 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 surface at a height r perpendicular to the optical axis 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, and a16 are the high-order aspheric coefficients of the corresponding aspheric surface, namely, the fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth orders. i r i The combination becomes the high-order terms corresponding to the aspheric surface, i = 4, 6, 8, 10, 12, 14, 16.

[0249] For example, 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 end 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] Figure 23 for Figure 21 The vertical axis chromatic aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Figure 24 for Figure 22 The vertical axis chromatic aberration curve of the zoom lens provided is at infinite object distance at the telephoto end. Figure 23 and Figure 24 , the vertical direction represents the normalized aperture, 0 represents the optical axis, the vertical axis vertex represents the maximum image height; the main wavelength is 546.07nm, the horizontal direction represents the offset relative to the main wavelength, the unit is micrometer (um). Figure 23 、 Figure 24 It can be seen that the vertical chromatic aberration at different wavelengths is controlled within a relatively small range, indicating that the vertical chromatic aberration of the zoom lens at different focal lengths is well controlled and can meet application requirements under normal conditions.

[0259] Figure 25 for Figure 21 The provided zoom lens has a ray fan diagram at infinite object distance at the wide-angle end. Figure 26 for Figure 22 The provided zoom lens has a ray fan diagram at the infinite object distance at the telephoto end. Figure 25 and Figure 26 In a single figure, the horizontal axis is the normalized beam diameter, and the vertical axis is the vertical axis aberration, where the image plane unit is mm / mm. Ideally, each curve should completely coincide with the horizontal axis, at which point 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 diffusion 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 25 、 Figure 26 As can be seen, the zoom lens's curves for each wavelength at all focal lengths and fields of view are all well aligned with the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, the curves for each color exhibit no significant dispersion, demonstrating that chromatic aberration is well corrected, meeting the requirements for this zoom lens.

[0260] Figure 27 for Figure 21 The provided zoom lens has a field curvature distortion curve at infinite object distance at the wide-angle end. Figure 28 for Figure 22 The provided zoom lens has a field curvature distortion curve at the telephoto end with infinite object distance. Figure 27 and Figure 28In the left coordinate system of the two figures, the horizontal coordinate represents the magnitude of the zoom lens field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents the meridian, S represents the arc loss; Figure 27 and Figure 28 It can be seen that the lens provided in this embodiment effectively controls field curvature from light with a wavelength of 436nm to light with a wavelength of 656nm. That is, when imaging, the difference in image quality between the center and the periphery is small. In the coordinate system on the right, the horizontal coordinate represents the degree of distortion in %, and the vertical coordinate represents the normalized image height in no unit. Figure 27 and Figure 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] Figure 29 for Figure 21 The axial aberration curve of the zoom lens provided at infinite object distance at the wide-angle end is Figure 30 for Figure 22 The provided zoom lens has an axial aberration curve at infinite object distance at the telephoto end. Figure 29 and Figure 30 , the vertical direction represents the normalized aperture, 0 represents the optical axis, the vertical axis vertex 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). Figure 29 and Figure 30 It can be seen that the axial aberrations at different wavelengths and normalized apertures of 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial chromatic aberration of this zoom lens at different focal lengths is well controlled and meets usage requirements.

[0262] In summary, in Example 1, Example 2, and Example 3 of the present application, the optical and physical parameters of the first to seventeenth lenses are 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 employed. 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 has been 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 zoom lens comprises 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, 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 variator lens group and the focus lens group move along the optical axis during zooming. The zoom lens comprises 17 lenses with optical power. 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 zoom lens assembly includes a fourth lens having negative optical power, a fifth lens having negative optical power, a sixth lens having positive optical power, and a seventh lens having 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; and 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 maintains a consistent diaphragm position relative to the image plane at different focal lengths, and the diaphragm diameter is the same at different focal lengths, satisfying the following condition: FNO≤1.50; where FNO is the aperture number of the zoom lens at all focal lengths; 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 zoom 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 zoom lens at the wide-angle end.

2. The zoom lens according to claim 1, wherein: Along the optical axis from the object side to the image side, 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 eighth lens is an aspherical lens; the twelfth lens is an aspherical lens; and the seventeenth lens is an aspherical lens.

4. The zoom lens according to claim 3, 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; vd8, vd12, and vd17 are the Abbe numbers of the eighth lens, the twelfth lens, and the seventeenth lens, respectively.

5. The zoom lens according to claim 1, wherein: The first fixed lens group includes at least one cemented lens; The variable magnification 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.

6. The zoom lens according to claim 5, wherein: The triplet lens composed of the ninth lens, the tenth lens and the eleventh lens satisfies: -1.018≤F9-10-11 / F3≤-0.897; Wherein, F9-10-11 represents the focal length of the combination of the ninth lens, the tenth lens and the eleventh lens, and F3 represents the focal length of the second fixed lens group.

7. The zoom lens according to claim 5, wherein: The thirteenth lens, the fourteenth lens, and the fifteenth lens are combined into a triplet lens, which satisfies: -2.337≤F13-14-15 / F4≤-1.946; Wherein, F13-14-15 represents the focal length of the combination of the thirteenth lens, the fourteenth lens and the fifteenth lens, and F4 represents the focal length of the focusing lens group.

8. The zoom lens according to claim 1, wherein: The zoom 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, and S4 is the maximum distance that the focus lens group moves along the optical axis.

9. 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