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, negative 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, positive, negative and positive; the focusing lens group is composed of two lenses, and the focal power is positive and negative. The third fixed lens group consists of four lenses, and the focal powers of the four lenses are respectively positive, negative, positive and negative; the seventh lens, the eighth lens and the fourteenth lens are aspheric lenses. The zoom lens can meet the use requirements of small distortion, large aperture and clear imaging on a 1 / 1.2 ''target surface and at the wave band of 405nm-656nm.

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 negative 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; the second fixed lens group includes an eighth lens with positive optical power, a ninth lens with positive optical power, a tenth lens with negative optical power and an eleventh lens with positive optical power;

[0009] The focusing lens group includes a twelfth lens with positive optical power and a thirteenth lens with negative optical power;

[0010] The third fixed lens group includes a fourteenth lens with positive optical power, a fifteenth lens with negative optical power, a sixteenth lens with positive optical power, and a seventeenth lens with negative optical power;

[0011] At the same time, the following conditions are met: FNO≤1.50;

[0012] Wherein, FNO is the aperture number of the zoom lens at the full focal length.

[0013] Optionally, along the direction from the object side to the image side of the optical axis, the surface of the lens close to the object plane is the object side surface, and the surface of the lens close to the image plane is the image side surface;

[0014] In the first fixed lens group, the surface shape of the first lens is convex-concave; the surface shape of the second lens is convex-concave; the surface shape of the third lens is convex-concave;

[0015] In the variable power lens group, the image side surface of the fourth lens is concave, the surface shape of the fifth lens is concave-concave, the surface shape of the sixth lens is convex-convex, and the surface shape of the seventh lens is concave-convex;

[0016] In the second fixed lens group, the surface shape of the eighth lens is convex-concave, the surface shape of the ninth lens is convex-convex, the surface shape of the tenth lens is convex-concave; the surface shape of the eleventh lens is convex-convex;

[0017] In the focusing lens group, the surface shape of the twelfth lens is convex-convex; the surface shape of the thirteenth lens is concave-concave;

[0018] In the third fixed lens group, the surface shape of the fourteenth lens is convex-convex, and the surface shape of the fifteenth lens is concave-concave; the image side surface of the sixteenth lens is convex-convex, and the surface shape of the seventeenth lens is concave-concave.

[0019] 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:

[0020] 5.53≤F1 / FW≤5.85;-1.53≤F2 / FW≤-1.39;

[0021] 1.23≤F3 / FW≤1.35;-2.36≤F4 / FW≤-1.95;2.88≤F5 / FW≤4.2;

[0022] 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.

[0023] Optionally, the variable power lens group and the focusing lens group satisfy the following relationship: 8.568≤S2 / S4≤24.5;

[0024] 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.

[0025] Optionally, at least one aspherical lens is included in each of the variable power lens group, the second fixed lens group, and the third fixed lens group; and the materials of the seventh lens, the eighth lens, and the fourteenth lens meet the following requirements:

[0026] 1.53≤nd7≤1.84; 37.29≤vd7≤55.46; 1.62≤nd8≤1.88; 28.19≤vd8≤44.51;

[0027] 1.60≤nd14≤1.88;37.21≤vd14≤60.44;

[0028] Among them, nd7, nd8, and nd14 are the refractive indices of the seventh lens, the eighth lens, and the fourteenth lens respectively, and vd7, vd8, and vd14 are the Abbe numbers of the seventh lens, the eighth lens, and the fourteenth lens respectively.

[0029] Optionally, at least one lens in the variable power lens group is an aspherical lens;

[0030] In the second fixed lens group, the eighth lens is an aspherical lens;

[0031] In the third fixed lens group, the fourteenth lens is an aspherical lens.

[0032] Optionally, the first fixed lens group and / or the second fixed lens group includes at least one cemented lens group.

[0033] Optionally, there is at least one cemented lens in the variable power lens group and / or the focusing lens group.

[0034] Optionally, the focal lengths of the wide-angle end and the telephoto end of the zoom lens need to satisfy the following relationship:

[0035] FT / FW ≥ 3.33;

[0036] Wherein, FW is the focal length of the zoom lens at the wide-angle end, and FT is the focal length of the zoom lens at the telephoto end.

[0037] Optionally, the total length of the zoom lens and the moving distance of the variable magnification lens group satisfy the following relationship:

[0038] 3.772≤TTL / S2≤3.995;

[0039] 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.

[0040] The zoom lens provided in the embodiment of the present application comprises a first fixed lens group, a variable power lens group, an aperture, a second fixed lens group, a focusing lens group, and a third fixed lens group, which are arranged in sequence from the object plane to the image plane along the optical axis, and the optical powers are respectively positive, negative, positive, negative, and positive; the first fixed lens group is composed of three lenses, and the optical powers are respectively negative, positive, and positive; the variable power lens group is composed of four lenses, and the optical powers are respectively negative, negative, positive, and negative; the second fixed lens group is composed of four lenses, and the optical powers are respectively positive, positive, negative, and positive; the focusing lens group is composed of two lenses, and the optical powers are respectively positive, negative, positive, and negative; the third fixed lens group is composed of four lenses, and the optical powers are respectively positive, negative, positive, and negative; the seventh lens, the eighth lens, and the fourteenth lens are aspherical lenses. The zoom lens can meet the use requirements of large aperture and clear imaging on a 1 / 1.2″ target surface and in the 405nm-656nm band. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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;

[0042] Figure 2 A schematic diagram of the structure of the zoom lens at the telephoto end provided in Embodiment 1 of the present application;

[0043] Figure 3 The vertical axis chromatic aberration curve of the zoom lens provided in Example 1 of the present application at the wide-angle end;

[0044] Figure 4 A light fan diagram of the zoom lens provided in Example 1 of the present application at the wide-angle end;

[0045] Figure 5 The axial aberration curve of the zoom lens provided in the first embodiment of the present application at the wide-angle end;

[0046] Figure 6 The vertical axis chromatic aberration curve of the zoom lens provided in Example 1 of the present application at the telephoto end;

[0047] Figure 7 A light fan diagram of the zoom lens at the telephoto end provided in Example 1 of the present application;

[0048] Figure 8 The axial aberration curve of the zoom lens provided in the first embodiment of the present application at the telephoto end;

[0049] Fig. 9A schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 2 of the present application;

[0050] Fig.10 A schematic diagram of the structure of the zoom lens at the telephoto end provided in the second embodiment of the present application;

[0051] Fig.11 The vertical axis chromatic aberration curve of the zoom lens provided in the second embodiment of the present application at the wide-angle end;

[0052] Fig.12 A light fan diagram of the zoom lens at the wide-angle end provided in Example 2 of the present application;

[0053] Fig.13 The axial aberration curve of the zoom lens provided in the second embodiment of the present application at the wide-angle end;

[0054] Fig.14 The vertical axis chromatic aberration curve of the zoom lens provided in the second embodiment of the present application at the telephoto end;

[0055] Fig.15 A light fan diagram of the zoom lens at the telephoto end provided in Example 2 of the present application;

[0056] Fig.16 The axial aberration curve of the zoom lens provided in the second embodiment of the present application at the telephoto end;

[0057] Fig.17 A schematic diagram of the structure of the zoom lens at the wide-angle end provided in Embodiment 3 of the present application;

[0058] Fig.18 A schematic diagram of the structure of the zoom lens at the telephoto end provided in Embodiment 3 of the present application;

[0059] Fig.19 The vertical axis chromatic aberration curve of the zoom lens provided in Example 3 of the present application at the wide-angle end;

[0060] Fig. 20 A light fan diagram of the zoom lens at the wide-angle end provided in Example 3 of the present application;

[0061] Fig.21 The axial aberration curve of the zoom lens provided in the third embodiment of the present application at the wide-angle end;

[0062] Fig. 22 The vertical axis chromatic aberration curve of the zoom lens provided in Example 3 of the present application at the telephoto end;

[0063] Fig.23 A light fan diagram of the zoom lens at the telephoto end provided in Example 3 of the present application;

[0064] Fig.24This is the axial aberration curve of the zoom lens provided in Example 3 of the present application at the telephoto end. DETAILED DESCRIPTION

[0065] 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.

[0066] 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 negative 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.

[0067] Along the optical axis from the object plane to the image plane:

[0068] 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.

[0069] 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 second fixed lens group G3 includes an eighth lens L8 with positive optical power, a ninth lens L9 with positive optical power, a tenth lens L10 with negative optical power and an eleventh lens L11 with positive optical power.

[0070] The focusing lens group G4 includes a twelfth lens L12 having positive refractive power and a thirteenth lens L13 having negative refractive power.

[0071] The third fixed lens group G5 includes a fourteenth lens L14 having positive power, a fifteenth lens L15 having negative power, a sixteenth lens L16 having positive power, and a seventeenth lens L17 having negative power.

[0072] The following conditions are met at the same time: FNO≤1.50; where FNO is the aperture number of the zoom lens at the full focal length.

[0073] 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 immovable 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.

[0074] 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.

[0075] 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.

[0076] 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).

[0077] 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.

[0078] 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 second fixed lens group G3 with positive focal length, the focusing lens group G4 with negative focal length, and the third fixed lens group G5 with positive focal length used at the rear end of the aperture STO can correct the aberration at the rear end of the lens, and cooperate with the lens group at the front end of the aperture STO to stabilize the imaging quality of the zoom lens.

[0079] 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 any time.

[0080] Furthermore, by controlling the aperture diameter of the aperture STO at different focal lengths to be the same, the aperture range can be structurally reduced, ensuring that the movable group of the lens has a longer moving distance, reducing the size of the zoom lens, and achieving a higher imaging magnification at the same time to meet usage requirements under different conditions.

[0081] 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.

[0082] In the first fixed lens group G1 , the surface shape of the first lens L1 is convex-concave; the surface shape of the second lens L2 is convex-concave; and the surface shape of the third lens L3 is convex-concave.

[0083] In the variator lens group G2, the image side surface of the fourth lens L4 is concave, the surface type of the fifth lens L5 is concave-concave, the surface type of the sixth lens L6 is convex-convex, and the surface type of the seventh lens L7 is concave-convex.

[0084] In the second fixed lens group G3, the surface type of the eighth lens L8 is convex-concave, the surface type of the ninth lens L9 is convex-convex, the surface type of the tenth lens L10 is convex-concave; and the surface type of the eleventh lens L11 is convex-convex.

[0085] 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 concave-concave.

[0086] In the third fixed lens group G5, the surface type of the fourteenth lens L14 is convex-convex, and the surface type of the fifteenth lens L15 is concave-concave; the image side surface of the sixteenth lens L16 is convex-convex, and the surface type of the seventeenth lens L17 is concave-concave.

[0087] 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.

[0088] Optionally, at least one lens in the variable power lens group G2 is an aspherical lens; in the second fixed lens group G3, the eighth lens L8 is an aspherical lens; in the third fixed lens group G5, the fourteenth lens L14 is an aspherical lens.

[0089] Specifically, if the seventh lens L7, the eighth lens L8 and the fourteenth lens L14 are all aspherical lenses, and the aperture STO is arranged between the seventh lens L7 and the eighth lens L8, when the light passes through the aperture STO, the use of the aspherical lens can well correct the aberrations at the front and rear ends of the aperture STO, and avoid the situation where the aberrations are 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 groups at the front and rear ends of the aperture STO.

[0090] In the embodiment of the present application, the aspherical lens of the zoom lens satisfies the following formula:

[0091]

[0092] 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.

[0093] Among them, the cost of lenses made of plastic is much lower than that of lenses made of glass. In the embodiment of the present application, one or more of the seventh lens L7, the eighth lens L8, and the fourteenth lens L14 can be made of plastic aspherical lenses, which can greatly reduce the cost of the zoom lens; or, one of the seventh lens L7, the eighth lens L8, and the fourteenth lens L14 can be made of a glass spherical lens, or a mixture of a glass aspherical lens and a plastic aspherical lens. 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 helps to improve the environmental adaptability of the zoom lens.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] Based on the above embodiments, Figure 1-Figure 2 The first fixed lens group G1 and / or the second fixed lens group G3 include at least one cemented lens.

[0098] For example, the first lens L1 and the second lens L2 can be combined into a doublet lens group. In other embodiments, the first lens L1 and the second lens L2 can also be used as two single lenses.

[0099] Specifically, the first lens L1 and the second lens L2 are combined into a double cemented lens group. 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 double cemented lens group after the first lens L1 and the second lens L2 are cemented is a convex-concave type, which is conducive to the smooth collection of object light into the imaging system, and can correct high-order aberrations to a large extent. At the same time, this shape can better collect light with a large field of view, ensuring the imaging requirements of a wide angle and a large field of view.

[0100] Among them, the glued lens group in the embodiment of the present application can also be called a glued lens.

[0101] Based on the above embodiments, Figure 1-Figure 2 The variable power lens group G2 includes at least one cemented lens.

[0102] For example, the fifth lens L5 and the sixth lens L6 are combined into a double cemented lens group. In other embodiments, the fifth lens L5 and the sixth lens L6 can also be used as two single lenses.

[0103] Specifically, by forming a front concave-convex lens by combining the fifth lens L5 and the sixth lens L6 in the zoom lens group G2 with a double cemented lens group, the air space between the fifth lens L5 and the sixth lens L6 can be effectively reduced, and the total length of the zoom lens can be reduced. When the light is diverged by the fifth lens L5 with a negative focal power and then enters the sixth lens L6 with a positive focal power for convergence, and then enters the seventh lens L7 with a negative focal power for divergence and then enters the eighth lens L8 with a positive focal power for convergence, the light can be diffused and focused for transmission multiple times, 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 cemented lenses can reduce the chromatic aberration and aberration generated at the front end, further improving the imaging quality.

[0104] At the same time, the combination of the double cemented lens group composed of the first lens L1 and the second lens L2 used in the first fixed lens group G1 and the double cemented lens group composed of the fifth lens L5 and the sixth lens L6 used in the zoom lens group G2, the combination of the two cemented lens groups 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.

[0105] Based on the above embodiments, Figure 1-Figure 2 The second fixed lens group G3 includes at least one cemented lens group.

[0106] For example, the tenth lens L10 and the eleventh lens L11 of the second fixed lens group G3 are combined into a doublet lens group or used as two single lenses.

[0107] Specifically, the double cemented lens group composed of the tenth lens L10 and the eleventh lens L11 in the second fixed lens group G3 is a convex-convex lens. After the light is continuously focused by the eighth lens L8 with a positive optical power and the ninth lens L9 with a positive optical power, it is diffused by the tenth lens L10 with a negative optical power and then converges into the eleventh lens L11 with a positive optical power, which is conducive to the light passing smoothly through the middle end of the lens. Before entering the third fixed lens group G5 at the rear end, a 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.

[0108] Based on the above embodiments, Figure 1-Figure 2 , there is at least one cemented lens in the focusing lens group G4.

[0109] For example, the twelfth lens L12 and the thirteenth lens L13 are combined into a double cemented lens group. In other embodiments, the twelfth lens L12 and the thirteenth lens L13 can also be used as two single lenses.

[0110] Specifically, by forming a front convex-concave lens by combining the twelfth lens L12 and the thirteenth lens L13 in the focus lens group G4 into a double cemented lens group, the air interval between the twelfth lens L12 and the thirteenth lens L13 can be effectively reduced, and the total length of the zoom lens can be reduced. When the light is converged by the twelfth lens L12 with a positive focal length and enters the thirteenth lens L13 with a 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.

[0111] Based on the above embodiments, Figure 1-Figure 2 , there is at least one cemented lens in the third fixed lens group G5.

[0112] For example, the fifteenth lens L15 and the sixteenth lens L16 can be combined into a cemented lens to form a double cemented lens group. In other embodiments, the fifteenth lens L15 and the sixteenth lens L16 can also be used as two single lenses.

[0113] Specifically, the fifteenth lens L15 and the sixteenth lens L16 are combined into a double cemented lens group, which is a concave-convex lens. After the light is converged by the fourteenth lens L14 with a positive focal power, it is diffused by the fifteenth lens L15 with a negative focal power, and then converged by the sixteenth lens L16 with a positive focal power, and diffused by the seventeenth lens L17 with a negative focal power to form an image on the image plane IMA. The double cemented lens group formed by the fifteenth lens L15 and the sixteenth lens L16 can correct the chromatic aberration and higher-order aberration generated in the focus lens group G4, and before imaging, reduce the aberration pressure of other groups in the lens at different focal lengths, thereby realizing the focus of the zoom lens at the full focal length.

[0114] 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, the bonding lens group can also reduce the number of assembly components between lenses, simplify the assembly procedures in the lens manufacturing process, reduce costs, and reduce the tolerance sensitivity of the lens unit due to tilt / eccentricity caused by the assembly process.

[0115] 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:

[0116] 5.53≤F1 / FW≤5.85;-1.53≤F2 / FW≤-1.39;

[0117] 1.23≤F3 / FW≤1.35;-2.36≤F4 / FW≤-1.95;2.88≤F5 / FW≤4.2;

[0118] Among them, F1, F2, F3, F4, and 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.

[0119] 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, correcting the influence of high-order aberrations on imaging quality to a great extent, expanding the field of view of the optical system, and expanding the scope of use of the optical system.

[0120] Based on the above embodiments, Figure 1-Figure 2 , the zoom lens group G2 and the focus lens group G4 satisfy the following relationship: 8.568≤S2 / S4≤24.5.

[0121] 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.

[0122] 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.

[0123] 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; and the materials of the seventh lens L7, the eighth lens L8 and the fourteenth lens L14 meet the following requirements:

[0124] 1.53≤nd7≤1.84; 37.29≤vd7≤55.46; 1.62≤nd8≤1.88; 28.19≤vd8≤44.51;

[0125] 1.60≤nd14≤1.88;37.21≤vd14≤60.44.

[0126] Among them, nd7, nd8, nd14 are the refractive indices of the seventh lens L7, the eighth lens L8 and the fourteenth lens L14 respectively, and vd7, vd8, vd14 are the Abbe numbers of the seventh lens L7, the eighth lens L8 and the fourteenth lens L14 respectively.

[0127] 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 the optical system, by adding aspherical lenses to the zoom lens group G2, the second fixed lens group G3, and the third fixed lens group G5 that need to move during the zooming process, and by reasonably matching the refractive index and Abbe number of the seventh lens L7, the eighth lens L8, and the fourteenth lens L14, 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, and ensuring illumination while improving the imaging quality of the lens.

[0128] 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 seventh lens L7, the eighth lens L8, and the fourteenth lens L14 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, thereby improving 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.

[0129] Based on the above embodiments, Figure 1-Figure 2 , the focal lengths of the wide-angle and telephoto ends of the zoom lens must satisfy the following relationship: FT / FW ≥ 3.33.

[0130] Among them, FW is the focal length of the zoom lens at the wide-angle end, and FT is the focal length of the zoom lens at the telephoto end.

[0131] Specifically, by controlling the focal length ratio between the wide-angle end and the telephoto end of the zoom lens, the distortion can be controlled within a reasonable small range while ensuring the zoom range and a large target surface, thus meeting the requirement of small distortion of the lens.

[0132] 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: 3.772≤TTL / S2≤3.995.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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 small distortion, large aperture, and clear imaging on a 1 / 1.2″ target surface and in the 405nm-656nm band.

[0137] 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.

[0138] Specific embodiments of the zoom lens applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0139] Embodiment 1

[0140] 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 variable power 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 negative optical focal length, a third fixed lens group G5 with positive optical focal length, and a flat glass CG, 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 variable power lens group G2 and the focusing lens group move along the optical axis when zooming.

[0141] Along the optical axis from the object plane to the image plane:

[0142] 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. The first lens L1 and the second lens L2 may be combined into a doublet lens group.

[0143] 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 seventh lens L7 is an aspherical lens. The fifth lens L5 and the sixth lens L6 are combined into a doublet lens group.

[0144] The second fixed lens group G3 includes an eighth lens L8 with positive focal power, a ninth lens L9 with positive focal power, a tenth lens L10 with negative focal power, and an eleventh lens L11 with positive focal power; the eighth lens L8 is an aspherical lens. The tenth lens L10 and the eleventh lens L11 are combined into a doublet lens group.

[0145] The focus lens group G4 includes a twelfth lens L12 having positive refractive power and a thirteenth lens L13 having negative refractive power. The twelfth lens L12 and the thirteenth lens L13 form a doublet lens group.

[0146] The third fixed lens group G5 includes a fourteenth lens L14 with positive focal power, a fifteenth lens L15 with negative focal power, a sixteenth lens L16 with positive focal power, and a seventeenth lens L17 with negative focal power; the fourteenth lens L14 is an aspherical lens. The fifteenth lens L15 and the sixteenth lens L16 form a double cemented lens group. The aperture number FNO of the zoom lens at the full focal length meets the following conditions: FNO≤1.50.

[0147] 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.

[0148] 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.

[0149] Table 1 Design values ​​of optical physical parameters of zoom lens

[0150]

[0151]

[0152] 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.

[0153] 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).

[0154] Table 2 Design values ​​of variable pitch of zoom lens

[0155] Wide angle Telephoto end Zoom interval 1 0.9198 32.7310 Zoom interval 2 32.2359 0.4247 Zoom interval 3 0.3964 3.6515 Zoom interval 4 8.0630 4.8079

[0156] The zoom intervals in Table 2 are different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0157] 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.

[0158] In this embodiment, the aspherical lens of the zoom lens may satisfy the following formula:

[0159]

[0160] 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.

[0161] Exemplarily, Table 3 describes in detail the aspheric coefficients of each lens in the first embodiment in a feasible implementation manner.

[0162] Table 3 Design values ​​of aspheric coefficients of each lens in zoom lens

[0163]

[0164] Among them, -2.811720863650E-05 means that the design value of the aspheric coefficient of the surface sequence mirror is S11, and the coefficient a4 is -2.81172086365*10 -5 , and so on.

[0165] As shown in Table 4, the zoom lens of the first embodiment achieves the following technical indicators:

[0166] Table 4 Parameters of the zoom lens of Example 1

[0167] Wide angle Telephoto end Image size(mm) Φ13.1 Φ13.1 Focal length(mm) 15.00 50.00 Wavelength(nm) 436-656 436-656 Total optical length (mm) 120.00 120.00

[0168] Furthermore, the performance parameters of the zoom lens provided in Example 1 were tested, and the test results are as follows:

[0169] Figure 3This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 1 of the present application at the wide-angle end. Figure 3 , the vertical direction represents the field of view, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum field of view; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Figure 3 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 the wide-angle end is well controlled and can meet the application requirements under normal conditions.

[0170] The ray fan diagram is one of the evaluation methods commonly used by optical designers. Figure 4 This is a light fan diagram of the zoom lens at the wide-angle end provided in Example 1 of the present application. Figure 4 In a single figure, the horizontal axis 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 4 It can be seen that the wavelengths of this zoom lens at each field of view at the wide-angle end 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.

[0171] The zoom lens is referred to as Z27, and in the light fan diagram of the embodiment of the present application, the image plane unit is millimeter / mm.

[0172] Figure 5 This is the axial aberration curve of the zoom lens at the wide-angle end provided in Example 1 of the present application. Figure 5 , 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 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Figure 5 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 aberrations of the zoom lens at the wide-angle end are well controlled and meet the usage requirements.

[0173] Figure 6 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 1 of the present application at the telephoto end. Figure 6 , the vertical direction represents the field of view, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum field of view; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Figure 6 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 the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0174] Figure 7 This is a light fan diagram of the zoom lens at the telephoto end provided in Example 1 of the present application. Figure 7 , 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 7 It can be seen that the wavelengths of this zoom lens at each field of view at the telephoto end are well aligned with the horizontal axis, indicating that the vertical aberration of each wavelength is well corrected. In addition, the curves of each color are not obviously dispersed, indicating that this zoom lens also has good correction for chromatic aberration, meeting the use requirements of this zoom lens.

[0175] Figure 8 This is the axial aberration curve of the zoom lens at the telephoto end provided in Example 1 of the present application. Figure 8 , 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 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Figure 8 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 aberrations of the zoom lens at the telephoto end are well controlled and meet the usage requirements.

[0176] Embodiment 2

[0177] Fig. 9 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.10 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. 9 and Fig.10 A zoom lens provided in Example 2 of the present application includes a first fixed lens group G1 with positive optical focal length, a zoom 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 negative optical focal length, a third fixed lens group G5 with positive optical focal length, and a flat glass CG, 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 zoom lens group G2 and the focusing lens group move along the optical axis when zooming.

[0178] Along the optical axis from the object plane to the image plane:

[0179] 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. The first lens L1 and the second lens L2 may be combined into a doublet lens group.

[0180] 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 seventh lens L7 is an aspherical lens. The fifth lens L5 and the sixth lens L6 are combined into a doublet lens group.

[0181] The second fixed lens group G3 includes an eighth lens L8 with positive focal power, a ninth lens L9 with positive focal power, a tenth lens L10 with negative focal power, and an eleventh lens L11 with positive focal power; the eighth lens L8 is an aspherical lens. The tenth lens L10 and the eleventh lens L11 are combined into a doublet lens group.

[0182] The focus lens group G4 includes a twelfth lens L12 having positive refractive power and a thirteenth lens L13 having negative refractive power. The twelfth lens L12 and the thirteenth lens L13 form a doublet lens group.

[0183] The third fixed lens group G5 includes a fourteenth lens L14 with positive focal power, a fifteenth lens L15 with negative focal power, a sixteenth lens L16 with positive focal power, and a seventeenth lens L17 with negative focal power; the fourteenth lens L14 is an aspherical lens. The fifteenth lens L15 and the sixteenth lens L16 form a double cemented lens group. The aperture number FNO of the zoom lens at the full focal length meets the following conditions: FNO≤1.50.

[0184] 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.

[0185] 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. 9 and Fig.10 Zoom lens shown.

[0186] Table 5 Design values ​​of optical physical parameters of zoom lens

[0187]

[0188]

[0189] 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.

[0190] Table 6 shows the values ​​of zoom intervals of the zoom lens at the wide-angle end and the telephoto end in Table 5, in millimeters (mm).

[0191] Table 6 Design values ​​of variable pitch of zoom lens

[0192] Wide angle Telephoto end Zoom interval 1 2.3362 32.6772 Zoom interval 2 30.8195 0.4785 Zoom interval 3 0.4945 4.0357 Zoom interval 4 7.9649 4.4237

[0193] The zoom intervals in Table 6 are different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0194] Combination Fig. 9 and Fig.10 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.

[0195] In this embodiment, the aspherical lens of the zoom lens may satisfy the following formula:

[0196]

[0197] 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.

[0198] Exemplarily, Table 7 describes in detail the aspheric coefficients of each lens in Example 2 of the present application in a feasible implementation manner.

[0199] Table 7 Design values ​​of aspheric coefficients of each lens in zoom lens

[0200]

[0201] Among them, -1.589187221867E-05 means that the coefficient a4 of the surface number S12 is -1.589187221867*10-5, and so on.

[0202] As shown in Table 8, the zoom lens of the second embodiment achieves the following technical indicators:

[0203] Table 8 Technical specifications of zoom lenses

[0204] Wide angle Telephoto end Image size(mm) Φ13.1 Φ13.1 Focal length(mm) 15.00 50.00 Wavelength(nm) 436-656 436-656 Total optical length (mm) 120.00 120.00

[0205] Furthermore, the performance parameters of the zoom lens provided in Example 2 were tested, and the test results are as follows:

[0206] Fig.11 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 2 of the present application at the wide-angle end. Fig.11 , the vertical direction represents the field of view, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum field of view; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Fig.11 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 the wide-angle end is well controlled and can meet the application requirements under normal conditions.

[0207] Fig.12 This is a light fan diagram of the zoom lens at the wide-angle end provided in Example 2 of the present application. Fig.12 , 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.12 It can be seen that the wavelengths of this zoom lens at each field of view at the wide-angle end 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.

[0208] Fig.13 This is the axial aberration curve of the zoom lens at the wide-angle end provided in Example 2 of the present application. Fig.13, 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.12 It can be seen that the wavelengths of this zoom lens at each field of view at the wide-angle end 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.

[0209] Fig.14 This is the vertical axis chromatic aberration curve of the zoom lens at the telephoto end provided in Example 2 of the present application. Fig.14 , the vertical direction represents the field of view, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum field of view; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). 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 the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0210] Fig.15 This is a light fan diagram of the zoom lens at the telephoto end provided in Example 2 of the present application. Fig.15 , 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 It can be seen that the wavelengths of this zoom lens at each field of view at the telephoto end are well aligned with the horizontal axis, indicating that the vertical aberration of each wavelength is well corrected. In addition, the curves of each color are not obviously dispersed, indicating that this zoom lens also has good correction for chromatic aberration, meeting the use requirements of this zoom lens.

[0211] Fig.16 This is the axial aberration curve of the zoom lens at the telephoto end provided in Example 2 of the present application. Fig.16 , 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 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Fig.16It 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 aberrations of the zoom lens at the telephoto end are well controlled and meet the usage requirements.

[0212] Embodiment 3

[0213] Fig.17 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.18 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.18 and Fig.19 A zoom lens provided in Example 3 of the present application includes a first fixed lens group G1 with positive optical focal length, a zoom 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 negative optical focal length, a third fixed lens group G5 with positive optical focal length, and a flat glass CG, 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 zoom lens group G2 and the focusing lens group move along the optical axis when zooming.

[0214] Along the optical axis from the object plane to the image plane:

[0215] 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. The first lens L1 and the second lens L2 may be combined into a doublet lens group.

[0216] 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 seventh lens L7 is an aspherical lens. The fifth lens L5 and the sixth lens L6 are combined into a doublet lens group.

[0217] The second fixed lens group G3 includes an eighth lens L8 with positive focal power, a ninth lens L9 with positive focal power, a tenth lens L10 with negative focal power, and an eleventh lens L11 with positive focal power; the eighth lens L8 is an aspherical lens. The tenth lens L10 and the eleventh lens L11 are combined into a doublet lens group.

[0218] The focus lens group G4 includes a twelfth lens L12 having positive refractive power and a thirteenth lens L13 having negative refractive power. The twelfth lens L12 and the thirteenth lens L13 form a doublet lens group.

[0219] The third fixed lens group G5 includes a fourteenth lens L14 with positive focal power, a fifteenth lens L15 with negative focal power, a sixteenth lens L16 with positive focal power, and a seventeenth lens L17 with negative focal power; the fourteenth lens L14 is an aspherical lens. The fifteenth lens L15 and the sixteenth lens L16 form a double cemented lens group. The aperture number FNO of the zoom lens at the full focal length meets the following conditions: FNO≤1.50.

[0220] 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.17 and Fig.18 Zoom lens shown.

[0221] Table 9 Design values ​​of optical physical parameters of zoom lens

[0222]

[0223]

[0224] 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.

[0225] 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).

[0226] Table 10 Design values ​​of variable pitch of zoom lens

[0227] Wide angle Telephoto end Zoom interval 1 1.0161 31.6700 Zoom interval 2 32.1396 1.4857 Zoom interval 3 1.2338 2.4850 Zoom interval 4 7.2256 5.9744

[0228] 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.

[0229] Combination Fig.17 and Fig.18As 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.

[0230] In this embodiment, the aspherical lens of the zoom lens may satisfy the following formula:

[0231]

[0232] 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.

[0233] Exemplarily, Table 11 describes in detail the aspheric coefficients of each lens in Example 3 of the present application in a feasible implementation manner.

[0234] Table 11 Design values ​​of aspheric coefficients of each lens in zoom lens

[0235]

[0236] Among them, -1.127436117376E-04 means that the coefficient a4 of the surface number S11 is -1.127436117376*10 -4 , and so on.

[0237] As shown in Table 12, the zoom lens of the third embodiment achieves the following technical indicators:

[0238] Table 12 Technical specifications of zoom lenses

[0239] Wide angle Telephoto end Image size(mm) Φ13.1 Φ13.1 Focal length(mm) 15.00 50.00 Wavelength(nm) 436-656 436-656 Total optical length (mm) 120.00 120.00

[0240] Furthermore, the performance parameters of the zoom lens provided in Example 3 were tested, and the test results are as follows:

[0241] Fig.19 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 3 of the present application at the wide-angle end. Fig.19 , the vertical direction represents the field of view, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum field of view; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Fig.19It 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 the wide-angle end is well controlled and can meet the application requirements under normal conditions.

[0242] Fig. 20 This is a light fan diagram of the zoom lens at the wide-angle end provided in Example 3 of the present application. Fig. 20 , 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. 20 It can be seen that the wavelengths of this zoom lens at each field of view at the wide-angle end 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.

[0243] Fig.21 This is the axial aberration curve of the zoom lens at the wide-angle end provided in Example 3 of the present application. Fig.21 , 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 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Fig.21 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 aberrations of the zoom lens at the wide-angle end are well controlled and meet the usage requirements.

[0244] Fig. 22 This is the vertical axis chromatic aberration curve of the zoom lens at the telephoto end provided in Example 3 of the present application. Fig. 22 , the vertical direction represents the field of view, 0 represents the optical axis, and the vertex in the vertical axis represents the maximum field of view; the main wavelength uses 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in micrometers (um). Fig. 22 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 the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0245] Fig.23 This is a light fan diagram of the zoom lens at the telephoto end provided in Example 3 of the present application. Fig.23, 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.23 It can be seen that the wavelengths of this zoom lens at each field of view at the telephoto end are well aligned with the horizontal axis, indicating that the vertical aberration of each wavelength is well corrected. In addition, the curves of each color are not obviously dispersed, indicating that this zoom lens also has good correction for chromatic aberration, meeting the use requirements of this zoom lens.

[0246] Fig.24 This is the axial aberration curve of the zoom lens at the telephoto end provided in Example 3 of the present application. Fig.24 , 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 546.07nm, and the horizontal direction represents the offset relative to the main wavelength in millimeters (mm). Fig.24 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 aberrations of the zoom lens at the telephoto end are well controlled and meet the usage requirements.

[0247] 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.

[0248] Table 13 Design values ​​of optical physical parameters of zoom lens

[0249] Scope of protection Example 1 Example 2 Example 3 Lower limit Upper limit FNO 1.492 / 1.50 1.492 / 1.50 1.50 / 1.50 - 1.50 F1 / FW 5.75 5.85 5.53 5.53 5.85 F2 / FW -1.50 -1.39 -1.53 -1.53 -1.39 F3 / FW 1.35 1.23 1.30 1.23 1.35 F4 / FW -2.36 -2.13 -1.95 -2.36 -1.95 F5 / FW 3.95 4.20 2.88 2.88 4.20 S2 / S4 9.77 8.57 24.50 8.57 24.50 FT / FW 3.33 3.33 3.33 3.33 3.33 TTL / S2 3.77 3.96 3.92 3.77 3.92 Nd7 1.53 1.84 1.53 1.53 1.84 Nd8 1.88 1.74 1.62 1.62 1.88 Nd14 1.74 1.60 1.88 1.60 1.88 Vd7 46.81 37.29 55.46 37.29 55.46 Vd8 40.04 28.19 44.51 28.19 44.51 Vd14 38.70 60.44 37.21 37.21 60.44

[0250] 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 negative focal power, and a third fixed lens group with positive focal power, which are arranged in sequence from the object plane to the image plane along the optical axis; 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 direction 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 positive optical power, a tenth lens with negative optical power and an eleventh lens with positive optical power; The focusing lens group includes a twelfth lens with positive optical power and a thirteenth lens with negative optical power; The third fixed lens group includes a fourteenth lens with positive optical power, a fifteenth lens with negative optical power, a sixteenth lens with positive optical power, and a seventeenth lens with negative optical power; At the same time, the following conditions are met: 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 of the lens close to the object plane is the object side surface, and the surface of the lens close to the image plane is the image side surface; In the first fixed lens group, the surface shape of the first lens is convex-concave; the surface shape of the second lens is convex-concave; the surface shape of the third lens is convex-concave; In the variable power lens group, the image side surface of the fourth lens is concave, the surface shape of the fifth lens is concave-concave, the surface shape of the sixth lens is convex-convex, and the surface shape of the seventh lens is concave-convex; In the second fixed lens group, the surface shape of the eighth lens is convex-concave, the surface shape of the ninth lens is convex-convex, the surface shape of the tenth lens is convex-concave; the surface shape of the eleventh lens is convex-convex; In the focusing lens group, the surface shape of the twelfth lens is convex-convex; the surface shape of the thirteenth lens is concave-concave; In the third fixed lens group, the surface shape of the fourteenth lens is convex-convex, and the surface shape of the fifteenth lens is concave-concave; the image side surface of the sixteenth lens is convex-convex, and the surface shape of the seventeenth lens is concave-concave.

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: 5.53≤F1 / FW≤5.85;-1.53≤F2 / FW≤-1.39; 1.23≤F3 / FW≤1.35;-2.36≤F4 / FW≤-1.95;2.88≤F5 / FW≤4.2; 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 variable power lens group and the focus lens group satisfy the following relationship: 8.568≤S2 / S4≤24.5; 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.

5. The zoom lens according to claim 1, wherein: There is at least one aspherical lens in each of the variable power lens group, the second fixed lens group and the third fixed lens group; and the materials of the seventh lens, the eighth lens and the fourteenth lens meet the following requirements: 1.53≤nd7≤1.84; 37.29≤vd7≤55.46; 1.62≤nd8≤1.88; 28.19≤vd8≤44.51; 1.60≤nd14≤1.88;37.21≤vd14≤60.44; Among them, nd7, nd8, and nd14 are the refractive indices of the seventh lens, the eighth lens, and the fourteenth lens respectively, and vd7, vd8, and vd14 are the Abbe numbers of the seventh lens, the eighth lens, and the fourteenth lens respectively.

6. The zoom lens according to claim 1, wherein: At least one lens in the variable power lens group is an aspherical lens; In the second fixed lens group, the eighth lens is an aspherical lens; In the third fixed lens group, the fourteenth lens is an aspherical lens.

7. The zoom lens according to claim 1, wherein: The first fixed lens group and / or the second fixed lens group at least includes a cemented lens group.

8. The zoom lens according to claim 1, wherein: There is at least one cemented lens in the variable power lens group and / or the focusing lens group.

9. The zoom lens according to claim 1, wherein: The focal lengths of the wide-angle end and the telephoto end of the zoom lens must satisfy the following relationship: FT / FW ≥ 3.33; Wherein, FW is the focal length of the zoom lens at the wide-angle end, and FT is the focal length of the zoom lens at the telephoto end.

10. The zoom lens according to claim 1, wherein: The total length of the zoom lens and the moving distance of the variable magnification lens group satisfy the following relationship: 3.772≤TTL / S2≤3.995; 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.

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