A zoom lens

Abstract

The application discloses a zoom lens, which comprises a first fixed lens group, a variable magnification lens group, a diaphragm, a second fixed lens group, a focusing lens group and a third fixed lens group arranged in sequence along an optical axis from an object plane to an image plane, and the optical powers are positive, negative, positive, negative and positive respectively; the first fixed lens group is composed of three lenses, and the optical powers are negative, positive and positive respectively; the variable magnification lens group is composed of four lenses, and the optical powers are negative, negative, positive and negative respectively; the second fixed lens group is composed of four lenses, and the optical powers are positive, positive, negative and positive respectively; the focusing lens group is composed of two lenses, and the optical powers are positive and negative respectively; the third fixed lens group is composed of four lenses, and the optical powers are positive, negative, positive and negative respectively; the seventh lens, the eighth lens and the fourteenth lens are aspherical 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 in a 405nm-656nm wave 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 negative 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, and 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 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] The following conditions must be met at the same time: 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 zoom lens group, the image side surface of the fourth lens is concave, the surface of the fifth lens is concave-concave, the surface of the sixth lens is convex-convex, and the surface 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 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:

[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 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.

[0023] Optionally, the zoom lens group and the focus 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, and S4 is the maximum distance that the focus lens group moves along the optical axis.

[0025] Optionally, each of the variable magnification lens group, the second fixed lens group, and the third fixed lens group includes at least one aspherical lens; 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; 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 zoom 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 magnification 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 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, negative, 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, positive, negative, and positive, respectively; the focusing lens group consists of two lenses, and the optical focal powers are positive and negative; the third fixed lens group consists of four lenses, and the optical focal powers are positive, negative, positive, and negative, respectively; the seventh lens, the eighth lens, and the fourteenth lens are aspherical lenses. This zoom lens can meet the 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 Example 1 of the present application;

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

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

[0044] Figure 4 This is a ray fan diagram of the zoom lens provided in Example 1 of the present application at the wide-angle end;

[0045] Figure 5 This is the axial aberration curve of the zoom lens provided in Example 1 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 This is a ray fan diagram of the zoom lens provided in Example 1 of the present application at the telephoto end;

[0048] Figure 8 The axial aberration curve of the zoom lens provided in Example 1 of the present application at the telephoto end;

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

[0050] Figure 10 A schematic diagram of the structure of the zoom lens at the telephoto end provided in Example 2 of the present application;

[0051] Figure 11 This is the vertical chromatic aberration curve of the zoom lens provided in Example 2 of the present application at the wide-angle end;

[0052] Figure 12 This is a ray fan diagram of the zoom lens provided in Example 2 of the present application at the wide-angle end;

[0053] Figure 13 This is the axial aberration curve of the zoom lens provided in Example 2 of the present application at the wide-angle end;

[0054] Figure 14 The vertical axis chromatic aberration curve of the zoom lens provided in Example 2 of the present application at the telephoto end;

[0055] Figure 15 This is a ray fan diagram of the zoom lens provided in Example 2 of the present application at the telephoto end;

[0056] Figure 16 This is the axial aberration curve of the zoom lens provided in Example 2 of the present application at the telephoto end;

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

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

[0059] Figure 19 This is the vertical chromatic aberration curve of the zoom lens provided in Example 3 of the present application at the wide-angle end;

[0060] Figure 20 This is a ray fan diagram of the zoom lens provided in Example 3 of the present application at the wide-angle end;

[0061] Figure 21 This is the axial aberration curve of the zoom lens provided in Example 3 of the present application at the wide-angle end;

[0062] Figure 22 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 3 of the present application at the telephoto end;

[0063] Figure 23 This is a ray fan diagram of the zoom lens provided in Example 3 of the present application at the telephoto end;

[0064] Figure 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 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.

[0066] 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 stop 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 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.

[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 refractive power, a fifteenth lens L15 having negative refractive power, a sixteenth lens L16 having positive refractive power, and a seventeenth lens L17 having negative refractive power.

[0072] The following conditions must be met at the same time: FNO ≤ 1.50; FNO is the aperture number of the zoom lens at all focal lengths.

[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 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 can adjust 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.

[0074] 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.

[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 of aspherical surfaces are not represented according to actual conditions.

[0076] 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).

[0077] 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.

[0078] Reference Figure 1 and Figure 2 The front end of the aperture 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 light passes through, increasing the aperture number of the zoom lens to meet the needs of different conditions. The rear end of the aperture STO uses a second fixed lens group G3 with positive focal length, a focusing lens group G4 with negative focal length, and a third fixed lens group G5 with positive focal length to correct aberrations at the rear end of the lens. Together with the lens group at the front end of the aperture STO, they stabilize the imaging quality of the zoom lens.

[0079] 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 end and the telephoto end at any time.

[0080] Furthermore, by controlling the aperture diameter of the aperture STO to be the same at different focal lengths, 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 the 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 of the first lens L1 is convex-concave; the surface of the second lens L2 is convex-concave; and the surface 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 of the fifth lens L5 is concave-concave, the surface of the sixth lens L6 is convex-convex, and the surface of the seventh lens L7 is concave-convex.

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

[0085] In the focusing lens group G4, the surface profile of the twelfth lens L12 is convex-convex; the surface profile of the thirteenth lens L13 is concave-concave.

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

[0087] 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.

[0088] Optionally, at least one lens in the zoom lens group G2 is an aspherical lens; in the second fixed lens group G3, the eighth lens L8 is an aspherical lens; and 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 lenses can well correct the aberrations at the front and rear ends of the aperture STO, avoiding 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 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.

[0093] The cost of the lens made of plastic material is much lower than that of the lens made of glass material. In the embodiments 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 lens, 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 is made of glass spherical lens, or made of glass aspherical lens and plastic aspherical lens, and the two types of materials of glass and plastic can also compensate for each other, which can balance the 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 materials of other lenses can be glass or plastic, which are not limited herein. 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 will not be described or limited herein.

[0095] The embodiments of the present application reasonably allocate the number of lenses and the optical power of each lens of the first fixed lens group G1, the variable lens group G2, the second fixed lens group G3, the focusing lens group G4 and the third fixed lens group G5, so that the optical power of each lens group and each lens is matched with each other to compensate for the aberration caused by the zoom movement of the variable lens group G2, which can effectively realize the aberration balance of each focal length and ensure the clarity of the image under different focal length conditions.

[0096] It should be noted that the materials of other lenses can be glass or plastic, which are not limited herein. 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 will not be described or limited herein.

[0097] On the basis of the above embodiments, with reference to Figure 1-Figure 2 The first fixed lens group G1 and / or the second fixed lens group G3 at least includes one glued lens.

[0098] For example, the first lens L1 and the second lens L2 can be combined into a double-glued 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 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, formed by the cementation of the first lens L1 and the second lens L2, has a convex-concave shape. This shape facilitates the smooth collection of object-side light into the imaging system, significantly correcting higher-order aberrations. Furthermore, this shape better captures light at a wide field of view, ensuring wide-angle imaging requirements.

[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 zoom 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 doublet 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 combining the fifth lens L5 and the sixth lens L6 in the zoom lens group G2 into a doublet, forming a front concave-convex lens, the air gap between the fifth lens L5 and the sixth lens L6 can be effectively reduced, thereby shortening the overall length of the zoom lens. Light is diffused by the negative-power fifth lens L5, then converges with the positive-power sixth lens L6. It then diffuses by the negative-power seventh lens L7, then converges with the positive-power eighth lens L8. This allows the light to be diffused and focused multiple times, allowing it to smoothly pass through the middle of the lens. Furthermore, the use of a doublet before the light enters the second fixed lens group G3 reduces chromatic aberration and aberrations generated at the front end, further improving image 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 focused by the eighth lens L8 with positive optical power and the ninth lens L9 with positive optical power in succession and then diffused by the tenth lens L10 with negative optical power, the light enters the eleventh lens L11 with positive optical power, which is beneficial to the light passing through the middle end of the lens gently. Before entering the third fixed lens group G5 at the rear end, the cemented lens is used to reduce the air gap between the tenth lens L10 and the eleventh lens L11, reduce the total length of the zoom lens, and reduce the chromatic aberration and aberration generated at the front end, thereby further improving the imaging quality.

[0108] On the basis of the above-mentioned embodiments, with reference to Figure 1-Figure 2 At least one cemented lens exists 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, the double cemented lens group composed of the twelfth lens L12 and the thirteenth lens L13 in the focusing lens group G4 forms a front convex-concave lens, which can effectively reduce the air gap between the twelfth lens L12 and the thirteenth lens L13 and reduce the total length of the zoom lens. When the light is focused by the twelfth lens L12 with positive optical power and then diffused by the thirteenth lens L13 with negative optical power to enter the third fixed lens group G5, it is beneficial to the correction of aberration in the full focal range, and improves the pixel imaging quality and the yield of finished products.

[0111] On the basis of the above-mentioned embodiments, with reference to Figure 1-Figure 2 At least one cemented lens exists 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 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 form a cemented doublet lens group with a concave-convex design. Light rays are converged by the positive-powered fourteenth lens L14, diffused by the negative-powered fifteenth lens L15, then converged by the positive-powered sixteenth lens L16, and diffused by the negative-powered seventeenth lens L17 before forming an image on the image plane IMA. This cemented doublet lens group, formed by the fifteenth and sixteenth lenses L15 and L16, corrects chromatic aberration and higher-order aberrations generated in the focusing lens group G4. Prior to forming an image, it reduces the aberration pressure on other lens groups at different focal lengths, thereby enabling the zoom lens to focus across the entire focal range.

[0114] At the same time, the cemented 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, the cemented 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 sensitivity of lens units to tolerances such as 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, 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.

[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] 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.

[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 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.

[0123] 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 contains 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] Wherein, nd7, nd8, and nd14 are the refractive indices of the seventh lens L7, the eighth lens L8, and the fourteenth lens L14, respectively; and vd7, vd8, and vd14 are the Abbe numbers of the seventh lens L7, the eighth lens L8, and the fourteenth lens L14, respectively.

[0127] To ensure stable imaging across the entire focal length of the optical system, the commonly used method is to individually achromatize and control aberrations within each lens group. Considering the excellent ability of aspherical lenses to control higher-order aberrations in optical systems, by adding aspherical lenses to the zoom lens group G2, the second fixed lens group G3, and the third fixed lens group G5, which require movement during zooming, and by properly matching the refractive indices and Abbe numbers of the seventh lens L7, the eighth lens L8, and the fourteenth lens L14, the aberrations of each group can be largely controlled, ensuring smooth light emission from the front, maintaining resolution and image height, and ensuring illumination while improving the lens' imaging quality.

[0128] 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. The seventh lens L7, the eighth lens L8, and the fourteenth lens L14 in the present embodiment 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 the present embodiment.

[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 magnification 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, ensuring that the required imaging quality and variable magnification are met under the condition of a small lens volume.

[0135] 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.

[0136] 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 low 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 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.

[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] Example 1

[0140] 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 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 variator lens group G2 and the focusing lens group move along the optical axis during 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 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 can 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 form a doublet lens group.

[0144] The second fixed lens group G3 includes a positive eighth lens L8, a positive ninth lens L9, a negative tenth lens L10, and a positive eleventh lens L11. The eighth lens L8 is an aspherical lens. The tenth lens L10 and the eleventh lens L11 form a cemented doublet.

[0145] The focusing 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 optical power, a fifteenth lens L15 with negative optical power, a sixteenth lens L16 with positive optical power, and a seventeenth lens L17 with negative optical power. Fourteenth lens L14 is an aspherical lens. Fifteenth lens L15 and sixteenth lens L16 form a cemented doublet. The zoom lens's aperture number (FNO) at all focal lengths satisfies the following condition: FNO ≤ 1.50.

[0147] 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.

[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] 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.

[0153] 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).

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

[0155] Wide-angle end 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] 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.

[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 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.

[0161] For example, 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 face-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 end 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 of the vertical axis represents the maximum field of view; the main wavelength is 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 this 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 ray 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 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 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 4 As can be seen, at the wide-angle end, the curves for each wavelength at each field of view of this zoom lens are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, there is no noticeable dispersion in the curves for each color, indicating that this zoom lens also effectively corrects chromatic aberration, meeting the requirements of its use.

[0171] The zoom lens is referred to as Z27. In the ray 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 provided in Example 1 of the present application at the wide-angle end. 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 at different wavelengths and normalized apertures of 0.3 to 1.0 are all controlled within a reasonable range, indicating that the axial aberrations of this zoom lens at the wide-angle end are well controlled and meet 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 of the vertical axis represents the maximum field of view; the main wavelength is 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 this zoom lens at the telephoto end is well controlled and can meet the application requirements under normal conditions.

[0174] Figure 7 This is a ray fan diagram of the zoom lens at the telephoto end provided in Example 1 of the present application. Figure 7 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 7 As can be seen, at the telephoto end, the curves for each wavelength in each field of view of this zoom lens are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, there is no noticeable dispersion in the curves for each color, indicating that this zoom lens also has good correction for chromatic aberration, meeting the requirements of this zoom lens.

[0175] Figure 8 This is the axial aberration curve of the zoom lens provided in Example 1 of the present application at the telephoto end. 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 the normalized aperture at different wavelengths of 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] Example 2

[0177] Figure 9 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 10 This is a schematic diagram of the structure of the zoom lens at the telephoto end provided in Example 2 of this application. Figure 9 and Figure 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 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 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 variator lens group G2 and the focusing lens group move along the optical axis during 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 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 can 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 form a doublet lens group.

[0181] The second fixed lens group G3 includes a positive eighth lens L8, a positive ninth lens L9, a negative tenth lens L10, and a positive eleventh lens L11. The eighth lens L8 is an aspherical lens. The tenth lens L10 and the eleventh lens L11 form a cemented doublet.

[0182] The focusing 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 optical power, a fifteenth lens L15 with negative optical power, a sixteenth lens L16 with positive optical power, and a seventeenth lens L17 with negative optical power. Fourteenth lens L14 is an aspherical lens. Fifteenth lens L15 and sixteenth lens L16 form a cemented doublet. The zoom lens's aperture number (FNO) at all focal lengths satisfies the following condition: FNO ≤ 1.50.

[0184] 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.

[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 Figure 9 and Figure 10 Zoom lens shown.

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

[0187]

[0188]

[0189] 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.

[0190] 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).

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

[0192] Wide-angle end 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 the different interval values ​​of the zoom lens at the wide-angle end and the telephoto end.

[0194] Combine Figure 9 and Figure 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 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.

[0198] 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.

[0199] Table 7 Design values ​​of aspheric coefficients of each lens in the 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 end 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] Figure 11 This is the vertical axis chromatic aberration curve of the zoom lens provided in Example 2 of this application at the wide-angle end. Figure 11 , the vertical direction represents the field of view, 0 represents the optical axis, and the vertex of the vertical axis represents the maximum field of view; the main wavelength is 546.07nm, and the horizontal direction represents the offset relative to the main wavelength, in micrometers (um). Figure 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 this zoom lens at the wide-angle end is well controlled and can meet the application requirements under normal conditions.

[0207] Figure 12 This is the ray fan diagram of the zoom lens at the wide-angle end provided in Example 2 of this application. Figure 12 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 12 As can be seen, at the wide-angle end, the curves for each wavelength at each field of view of this zoom lens are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, there is no noticeable dispersion in the curves for each color, indicating that this zoom lens also effectively corrects chromatic aberration, meeting the requirements of its use.

[0208] Figure 13 This is the axial aberration curve of the zoom lens provided in Example 2 of the present application at the wide-angle end. Figure 13In 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 12 As can be seen, at the wide-angle end, the curves for each wavelength at each field of view of this zoom lens are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, there is no noticeable dispersion in the curves for each color, indicating that this zoom lens also effectively corrects chromatic aberration, meeting the requirements of its use.

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

[0210] Figure 15 This is a ray fan diagram of the zoom lens at the telephoto end provided in Example 2 of this application. Figure 15 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 As can be seen, at the telephoto end, the curves for each wavelength in each field of view of this zoom lens are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, there is no noticeable dispersion in the curves for each color, indicating that this zoom lens also has good correction for chromatic aberration, meeting the requirements of this zoom lens.

[0211] Figure 16 This is the axial aberration curve of the zoom lens at the telephoto end provided in Example 2 of the present application. Figure 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). Figure 16It can be seen that the axial aberration of different wavelengths 0.3-1.0 normalized aperture is controlled in a reasonable range, which shows that the axial aberration of the zoom lens at the long focal end is well controlled, and the use requirement is met.

[0212] Embodiment Three

[0213] Figure 17 A structure schematic view of a zoom lens provided by Embodiment Three of the present application at the wide-angle end is shown in the following figure, Figure 18 A structure schematic view of a zoom lens provided by Embodiment Three of the present application at the long focal end is shown in the following figure. Figure 18 and Figure 19 A zoom lens provided by Embodiment Three of the present application includes, arranged in order along the optical axis from the object plane to the image plane, a first fixed lens group G1 with positive focal power, a variable magnification lens group G2 with negative focal power, a diaphragm STO, a second fixed lens group G3 with positive focal power, a focusing lens group G4 with negative focal power, a third fixed lens group G5 with positive focal power, and a plane glass CG; the first fixed lens group G1 and the second fixed lens group G3 are fixed, and the variable magnification lens group G2 and the focusing lens group move along the optical axis direction during zooming.

[0214] In the direction of the optical axis from the object plane to the image plane:

[0215] The first fixed lens group G1 includes a first lens L1 with negative focal power, a second lens L2 with positive focal power, and a third lens L3 with positive focal power. The first lens L1 and the second lens L2 can be combined into a doublet lens group.

[0216] The variable magnification lens group G2 includes a fourth lens L4 with negative focal power, a fifth lens L5 with negative focal power, a sixth lens L6 with positive focal power, and a seventh lens L7 with negative focal power; the seventh lens L7 is an aspheric 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 aspheric lens. The tenth lens L10 and the eleventh lens L11 are combined into a doublet lens group.

[0218] The focusing lens group G4 includes a twelfth lens L12 with positive focal power and a thirteenth lens L13 with negative focal power. The twelfth lens L12 and the thirteenth lens L13 are combined into a doublet lens group.

[0219] The third fixed lens group G5 includes a fourteenth lens L14 with positive optical power, a fifteenth lens L15 with negative optical power, a sixteenth lens L16 with positive optical power, and a seventeenth lens L17 with negative optical power. Fourteenth lens L14 is an aspherical lens. Fifteenth lens L15 and sixteenth lens L16 form a cemented doublet. The zoom lens's aperture number (FNO) at all focal lengths satisfies the following condition: 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 Figure 17 and Figure 18 Zoom lens shown.

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

[0222]

[0223]

[0224] 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.

[0225] 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).

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

[0227] Wide-angle end 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] 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] Combine Figure 17 and Figure 18As 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.

[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 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.

[0233] 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.

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

[0242] Figure 20 This is the ray fan diagram of the zoom lens at the wide-angle end provided in Example 3 of this application. Figure 20 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 20 As can be seen, at the wide-angle end, the curves for each wavelength at each field of view of this zoom lens are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, there is no noticeable dispersion in the curves for each color, indicating that this zoom lens also effectively corrects chromatic aberration, meeting the requirements of its use.

[0243] Figure 21 This is the axial aberration curve of the zoom lens at the wide-angle end provided in Example 3 of this application. Figure 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). Figure 21 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 aberrations of this zoom lens at the wide-angle end are well controlled and meet usage requirements.

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

[0245] Figure 23 This is the ray fan diagram of the zoom lens at the telephoto end provided in Example 3 of this application. Figure 23In 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 23 As can be seen, at the telephoto end, the curves for each wavelength in each field of view of this zoom lens are very close to the horizontal axis, indicating that vertical aberrations at each wavelength are well corrected. Furthermore, there is no noticeable dispersion in the curves for each color, indicating that this zoom lens also has good correction for chromatic aberration, meeting the requirements of this zoom lens.

[0246] Figure 24 This is the axial aberration curve of the zoom lens at the telephoto end provided in Example 3 of the present application. Figure 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). Figure 24 It can be seen that the axial aberrations of the normalized aperture at different wavelengths of 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 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.

[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 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 optical 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 negative optical power, and a third fixed lens group with positive optical power, which are arranged in sequence along the optical axis from the object plane to the image plane; the first fixed lens group, the second fixed lens group, and the third fixed lens group are fixed, and the variator lens group and the focus lens group move along the optical axis during zooming; 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, which are arranged in sequence along the optical axis from the object plane to the image plane; 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, which are arranged in sequence along the optical axis from the object plane to the image plane; 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, which are arranged in sequence along the optical axis from the object plane to the image plane; The focusing lens group includes a twelfth lens with positive optical power and a thirteenth lens with negative optical power, which are arranged in sequence from the object plane to the image plane along the optical axis; The third fixed lens group includes a fourteenth lens having positive optical power, a fifteenth lens having negative optical power, a sixteenth lens having positive optical power, and a seventeenth lens having negative optical power, arranged in sequence along the optical axis from the object plane to the image plane. The number of lenses having optical power in the zoom lens is 17. The focal lengths of the lens groups of the zoom lens and the focal length of the zoom 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 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 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 zoom lens group, the image side surface of the fourth lens is concave, the surface of the fifth lens is concave-concave, the surface of the sixth lens is convex-convex, and the surface 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 surface shape 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 zoom 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, and S4 is the maximum distance that the focus lens group moves along the optical axis.

4. The zoom lens according to claim 1, wherein: Each of the zoom lens group, the second fixed lens group, and the third fixed lens group includes an aspheric lens; 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; vd7, vd8, and vd14 are the Abbe numbers of the seventh lens, the eighth lens, and the fourteenth lens, respectively.

5. The zoom lens according to claim 1, wherein: The zoom lens group has one lens that 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.

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

7. The zoom lens according to claim 1, wherein: There is a cemented lens in the zoom lens group and / or the focus lens group.

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

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: 3.772≤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.

Images