Long-focus zoom lens
By designing a telephoto zoom lens containing spherical lenses, the problem of insufficient focus range and zoom range of existing lenses is solved, efficient focal length adjustment and low-cost production are achieved, and high-pixel detectors are adapted.
Patent Information
- Application Number
- CN202422273998.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-09-18
AI Technical Summary
The existing telephoto continuous zoom optical lens cannot meet actual needs in the focus range and zoom range, and the use of non-spherical lenses increases processing difficulty and production costs.
A telephoto zoom lens is designed. The optical system consists of the front fixed group, the focus group, the middle fixed group, the zoom group, the compensation group and the rear fixed group. It uses spherical lenses to meet the specific focal length and air gap relationship and avoid the use of aspherical lenses.
The focal length adjustment of 300mm to 600mm is achieved, the variable-magnification ratio reaches 12 times, and the object square resolution reaches 42 wire pairs, reducing processing difficulty and cost, and adapting to a 40-megapixel-level detector.
Smart Images
Figure CN223155305U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of lenses, and particularly relates to a long - focal - length zoom lens. Background Art
[0002] In the field of optical imaging technology, compared with traditional zoom lenses, continuous zoom lenses with large magnification ratios exhibit more excellent performance in various practical scenarios such as security, reconnaissance, and medical surgery. However, the focusing range and zoom range of existing long - focal - length continuous zoom optical lenses on the market cannot meet the actual use requirements. At the same time, aspherical lenses are used in long - focal - length continuous zoom optical lenses in the market, which greatly increases the processing difficulty and production cost. Content of the Utility Model
[0003] The utility model makes improvements to the above - mentioned problems existing in the prior art, that is, the technical problem to be solved by the utility model is to provide a long - focal - length zoom lens.
[0004] To achieve the above object, the technical solution adopted by the utility model is: a long - focal - length zoom lens, the optical system of the lens includes a front fixed group, a focusing group, a middle fixed group, a zoom group, a compensating group, and a rear fixed group arranged in sequence from the object space to the image space along the optical axis direction. The front fixed group is composed of a negative meniscus lens A1 and a biconvex lens A2, and the negative meniscus lens A1 and the biconvex lens A2 are closely adhered to form a first cemented group G1; the focusing group is a biconvex lens A3; the middle fixed group is composed of a positive meniscus lens A4 and a plano - concave lens A5, and the positive meniscus lens A4 and the plano - concave lens A5 are closely adhered to form a second cemented group G2; the zoom group is composed of a biconvex lens A6 and a biconcave lens A7, and the biconvex lens A6 and the biconcave lens A7 are closely adhered to form a third cemented group G3; the compensating group is composed of a biconcave lens A8 and a biconvex lens A9, and the biconcave lens A8 and the biconvex lens A9 are closely adhered to form a fourth cemented group G4; the rear fixed group is composed of a biconvex lens A10, a biconvex lens A11, and a biconcave lens A12, and the biconvex lens A11 and the biconcave lens A12 are closely adhered to form a fifth cemented group G5.
[0005] Further, when the lens is in the high - magnification state, the distance TTL from the object side surface of the first cemented group to the imaging surface and the focal - length variable △f when the lens is in the high - magnification state and the low - magnification state satisfy: 2 < TTL / △f < 5.
[0006] Further, when the lens is in the high magnification state, the combined total focal length of the first cemented group G1 and the biconvex lens A3 is f6; the combined total focal length of the second cemented group G2, the third cemented group G3, the fourth cemented group G4, and the biconvex lens A10 is f7, satisfying the following relationship: 0.1 < f6 / f7 < 0.3; when the lens is in the low magnification state, the combined total focal length of the first cemented group G1 and the biconvex lens A3 is f8, and the combined total focal length of the second cemented group G2, the third cemented group G3, the fourth cemented group G4, and the biconvex lens A10 is f9, satisfying the following relationship: 5.5 < f8 / f9 < 7.5.
[0007] Further, when the focal length of the lens is in the high magnification state is ft1 and the object distance of the lens is D, they satisfy the following relationship: 0.1 < ft1 / D < 0.2; when the object distance of the lens is d, it satisfies the following relationship: 0.1 < ft1 / d < 0.3; when the focal length of the lens is in the low magnification state is ft2 and the object distance of the lens is D, they satisfy the following relationship: 0.01 < ft2 / D < 0.1, and when the object distance of the lens is d, it satisfies the following relationship: 0.1 < ft2 / d < 0.2.
[0008] Further, the distance TTL from the object side of the first cemented group G1 to the imaging plane on the optical axis satisfies: 1.0 < TTL / ft1 < 2.5 with respect to the focal length ft1 when the lens is in the high magnification state; the distance TTL from the object side of the first cemented group G1 to the imaging plane on the optical axis satisfies: 2.0 < TTL / ft2 < 4.0 with respect to the focal length ft2 when the lens is in the low magnification state.
[0009] Further, when the lens is in the high magnification state, the combined total focal length of the biconvex lens A3, the second cemented group G2, and the third cemented group G3 is f10, and the combined total focal length of the biconvex lens A10 and the fifth cemented group G5 is f11, and they satisfy: 18 < f10 / f11 < 19; when the lens is in the low magnification state, the combined total focal length of the biconvex lens A3, the second cemented group G2, and the third cemented group G3 is f12, and the combined total focal length of the biconvex lens A10 and the fifth cemented group G5 is f13, and they satisfy: -5 < f12 / f13 < -3.
[0010] Further, when the lens switches from the low magnification state to the high magnification state, the change value of the air gap of the second cemented group G2 and the third cemented group G3 on the optical axis is △D1; when the lens switches from the low magnification state to the high magnification state, the change value of the air gap of the second cemented group G2 and the fourth cemented group G4 on the optical axis is △D2, and they satisfy: 3 < |△D2 / △D1| < 5.
[0011] Furthermore, the following relationships are satisfied between the focal length f1 of the first cemented group G1 and the focal length f2 of the biconvex lens A3: 6 < f1 / f2 < 8; the shortest object distance of the lens is u, and the focal length of the first cemented group G1 is f1, and they satisfy the following relationship: 0.1 < u / f1 < 1.5; the focal length of the fifth cemented group G5 is f5, and the image distance of the lens is v, satisfying the following relationship: -1.5 < f5 / v < -0.5.
[0012] Furthermore, the focal length of the rear fixed group is f14, and the image circle of the lens is L, satisfying the following relationship: 1.0 < f14 / L < 2.5.
[0013] Furthermore, the focusing group, the zooming group, and the compensating group can all move along the optical axis direction. During the zooming process, the air gap change range between the front fixed group and the focusing group is 1.0000 mm to 10.6218 mm, the air gap change range between the zooming group and the middle fixed group is 1.5000 mm to 26.2761 mm, the air gap change range between the zooming group and the compensating group is 20.1501 mm to 2.0000 mm, and the air gap change range between the compensating group and the rear fixed group is 7.6261 mm to 1.0000 mm; the air gap between the biconvex lens A10 and the fifth cemented group G5 is 0.5000 mm, the air gap between the first cemented group G1 and the second cemented group G2 is 18.5734 mm, and the air gap between the second cemented group G2 and the biconvex lens A10 is 36.4438 mm
[0014] Furthermore, the glass refractive index N1 and the dispersion coefficient V1 of the negative meniscus lens A1 and the glass refractive index N2 and the dispersion coefficient V2 of the biconvex lens A2 satisfy the following relationships: 2.0 > N1 > N2 > 1.0, V1 ≥ 35, V2 ≥ 75; the glass refractive index N2 and the dispersion coefficient V2 of the biconvex lens A2 and the glass refractive index N3 and the dispersion coefficient V3 of the biconvex lens A3 satisfy the following relationships: 1.8 > N2 > N3 > 1.0, V2 ≥ 75, V3 ≥ 85; the glass refractive index N6 and the dispersion coefficient V6 of the biconvex lens A6 and the glass refractive index N7 and the dispersion coefficient V7 of the biconcave lens A7 satisfy the following relationships: 2.5 > N6 > N7 > 1.0, V6 ≥ 15, V7 ≥ 35; the glass refractive index N8 and the dispersion coefficient V8 of the biconcave lens A8 and the glass refractive index N9 and the dispersion coefficient V9 of the biconvex lens A9 satisfy the following relationships: 1.0 < N8 < N9 < 2.5, V8 ≥ 35, V9 ≥ 15.
[0015] Compared with the prior art, the utility model has the following effects: The utility model is reasonably designed, with a long focal length and large zoom design in the structure. The focal length can be adjusted from 300mm to 600mm, the zoom ratio reaches 12 times, the object space resolution reaches 42 line pairs, and it can be adapted to a 40 million pixel detector with a pixel size of 2μm at the same time. Description of the Drawings
[0016] Figure 1 is a schematic diagram of the optical system of the embodiment of the utility model;
[0017] Figure 2 is a schematic diagram of the state of the long focal length of 300mm and the magnification of 0.05 times in the embodiment of the utility model;
[0018] Figure 3 is a schematic diagram of the state of the long focal length of 300mm and the magnification of 0.6 times in the embodiment of the utility model;
[0019] Figure 4 is a schematic diagram of the state of the long focal length at infinity in the embodiment of the utility model;
[0020] Figure 5 is the long focus spot diagram of the embodiment of the utility model;
[0021] Figure 6 is a schematic diagram of the long focal length transfer function of the embodiment of the utility model;
[0022] Figure 7 is a schematic diagram of the long focal length field curvature and distortion of the embodiment of the utility model;
[0023] Figure 8 is a schematic diagram of the long focal length chromatic aberration of the embodiment of the utility model;
[0024] Figure 9 is the short focus spot diagram of the embodiment of the utility model;
[0025] Figure 10 is a schematic diagram of the short focal length transfer function of the embodiment of the utility model;
[0026] Figure 11 is a schematic diagram of the short focal length field curvature and distortion of the embodiment of the utility model;
[0027] Figure 12 is a schematic diagram of the short focal length chromatic aberration of the embodiment of the utility model;
[0028] Figure 13 is the spot diagram at infinity of the embodiment of the utility model;
[0029] Figure 14 is a schematic diagram of the transfer function at infinity of the embodiment of the utility model;
[0030] Figure 15 It is a schematic diagram of the field curvature distortion at infinity in the embodiment of the present utility model;
[0031] Figure 16 It is a schematic diagram of the chromatic aberration at infinity in the embodiment of the present utility model.
[0032] In the figure:
[0033] 1 - Front fixed group; 2 - Focusing group; 3 - Middle fixed group; 4 - Zooming group; 5 - Compensation group; 6 - Rear fixed group; A1 - Negative meniscus lens A1; A2 - Double convex lens A2; A3 - Double convex lens A3; A4 - Positive meniscus lens A4; A5 - Plano - concave lens A5; A6 - Double convex lens A6; A7 - Double concave lens A7; A8 - Double concave lens A8; A9 - Double convex lens A9; A10 - Double convex lens A10; A11 - Double convex lens A11; A12 - Double concave lens A12; G1 - First cemented group G1; G2 - Second cemented group G2; G3 - Third cemented group G3; G4 - Fourth cemented group G4; G5 - Fifth cemented group G5. Specific embodiments
[0034] The present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0035] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.
[0036] Such as Figures 1 - 16As shown in the figure, a long - focal - length zoom lens of the present utility model uses a long - focal - length and large - magnification design in terms of structure. It can reach a maximum long - focal - length of 600 mm and a maximum magnification of 12 times. It not only has a wide range of focal lengths but also can match a detector with a pixel level of 40 million in design. Specifically: The optical system of the lens includes a front fixed group 1, a focusing group 2, a middle fixed group 3, a zooming group 4, a compensating group 5, and a rear fixed group 6 arranged in sequence from the object space to the image space along the optical axis direction. The front fixed group 1 is composed of a negative meniscus lens A1 and a biconvex lens A2, and the negative meniscus lens A1 and the biconvex lens A2 are closely joined to form a first cemented group G1; the focusing group 2 is a biconvex lens A3; the middle fixed group 3 is composed of a positive meniscus lens A4 and a plano - concave lens A5, and the positive meniscus lens A4 and the plano - concave lens A5 are closely joined to form a second cemented group G2; the zooming group 4 is composed of a biconvex lens A6 and a biconcave lens A7, and the biconvex lens A6 and the biconcave lens A7 are closely joined to form a third cemented group G3; the compensating group 5 is composed of a biconcave lens A8 and a biconvex lens A9, and the biconcave lens A8 and the biconvex lens A9 are closely joined to form a fourth cemented group G4; the rear fixed group 6 is composed of a biconvex lens A10, a biconvex lens A11, and a biconcave lens A12, and the biconvex lens A11 and the biconcave lens A12 are closely joined to form a fifth cemented group G5.
[0037] In this embodiment, when the lens is in the high - magnification state, the total distance from the object side surface S1 of the first cemented group to the imaging surface is TTL, and it satisfies the following relationship with the focal - length variable △f when the lens is in the high - magnification state and the low - magnification state: 2 < TTL / △f < 5. Preferably, TTL / △f = 3.474.
[0038] In this embodiment, when the lens is in the high - magnification state, the combined total focal length of the first cemented group G1 and the biconvex lens A3 is f6; the combined total focal length of the second cemented group G2, the third cemented group G3, the fourth cemented group G4, and the biconvex lens A10 is f7, and they satisfy the following relationship: 0.1 < f6 / f7 < 0.3. Preferably, f6 / f7 = 0.190.
[0039] In this embodiment, when the lens is in the low - magnification state, the combined total focal length of the first cemented group G1 and the biconvex lens A3 is f8, and the combined total focal length of the second cemented group G2, the third cemented group G3, the fourth cemented group G4, and the biconvex lens A10 is f9, and they satisfy the following relationship: 5.5 < f8 / f9 < 7.5. Preferably, f8 / f9 = 6.726.
[0040] In this embodiment, when the focal length of the lens is in the high - magnification state is ft1 and the object distance of the lens is D, they satisfy the following relationship: 0.1 < ft1 / D < 0.2. Preferably, when the object distance D = 600 mm, ft1 / D = 0.117.
[0041] In this embodiment, the focal length of the lens in the high magnification state is ft1. When the object distance of the lens is d, the following relationship is satisfied: 0.1 < ft1 / d < 0.3. Preferably, when the object distance of the lens is d = 300 mm, ft1 / d = 0.234.
[0042] In this embodiment, the focal length of the lens in the low magnification state is ft2. When the object distance of the lens is D, they satisfy the following relationship: 0.01 < ft2 / D < 0.1. Preferably, when the object distance of the lens is D = 600 mm, ft2 / D = 0.061.
[0043] In this embodiment, the focal length of the lens in the low magnification state is ft2. When the object distance of the lens is d, the following relationship is satisfied: 0.1 < ft2 / d < 0.2. Preferably, when the object distance of the lens is d = 300 mm, ft2 / d = 0.121.
[0044] In this embodiment, when the lens is in the high magnification state, the distance TTL from the object side surface S1 of the first cemented group G1 to the imaging surface on the optical axis and the focal length ft1 of the lens in the high magnification state satisfy: 1.0 < TTL / ft1 < 2.5. Preferably, TTL / ft1 = 1.676.
[0045] In this embodiment, the distance TTL from the object side surface S1 of the first cemented group G1 to the imaging surface on the optical axis and the focal length ft2 of the lens in the low magnification state satisfy: 2.0 < TTL / ft2 < 4.0. Preferably, TTL / ft2 = 3.240.
[0046] In this embodiment, when the lens is in the high magnification state, the combined total focal length of the combination of the biconvex lens A3, the second cemented group G2, and the third cemented group G3 is f10, and the combined total focal length of the combination of the biconvex lens A10 and the fifth cemented group G5 is f11. They satisfy: 18 < f10 / f11 < 19. Preferably, f10 / f11 = 17.090.
[0047] In this embodiment, when the lens is in the low magnification state, the combined total focal length of the combination of the biconvex lens A3, the second cemented group G2, and the third cemented group G3 is f12, and the combined total focal length of the combination of the biconvex lens A10 and the fifth cemented group G5 is f13. They satisfy: -5 < f12 / f13 < -3. Preferably, f12 / f13 = 3.953.
[0048] In this embodiment, when the lens switches from the low magnification state to the high magnification state, the change value of the air gap on the optical axis between the second cemented group G2 and the third cemented group G3 is ΔD1; when the lens switches from the low magnification state to the high magnification state, the change value of the air gap on the optical axis between the second cemented group G2 and the fourth cemented group G4 is ΔD2, and they satisfy: 3 < |ΔD2 / ΔD1| < 5. Preferably, |ΔD2 / ΔD1| = 3.249
[0049] In this embodiment, the focal length f1 of the first cemented group G1 and the focal length f2 of the biconvex lens A3 satisfy: 6 < f1 / f2 < 8. Preferably, f1 / f2 = 7.209.
[0050] In this embodiment, the shortest object distance of the lens is u, and the focal length of the first cemented group G1 is f1, and they satisfy the following relationship: 0.1 < u / f1 < 1.5. Preferably, when the shortest object distance of the lens is u = 300 mm, u / f1 = 0.745.
[0051] In this embodiment, the focal length of the fifth cemented group G5 is f5, and the image distance of the lens is v, satisfying the following relationship: -1.5 < f5 / v < -0.5. Preferably, when the image distance of the lens is v = 42.749, f5 / v = -0.840.
[0052] In this embodiment, the focal length of the rear fixed group is f14, and the image circle of the lens is L, satisfying the following relationship: 1.0 < f14 / L < 2.5. Preferably, when the image circle of the lens is L = 9, f14 / L = 1.582.
[0053] In this embodiment, the focusing group, the zooming group and the compensating group are movable groups and can move along the optical axis direction. During the zooming process, the air interval change range between the front fixed group and the focusing group is 1.0000 mm (short focal length) to 10.6218 (long focal length) mm, the air interval change range between the zooming group and the middle fixed group is 1.5000 mm (short focal length) to 26.2761 (long focal length) mm, the air interval change range between the zooming group and the compensating group is 20.1501 mm (short focal length) to 2.0000 (long focal length) mm, and the air interval change range between the compensating group and the rear fixed group is 7.6261 mm (short focal length) to 1.0000 (long focal length) mm.
[0054] In this embodiment, in the rear fixed group, the air interval between the biconvex lens A10 and the fifth cemented group G5 is 0.5000 mm, the air interval between the first cemented group G1 and the second cemented group G2 is 18.5734 mm, and the air interval between the second cemented group G2 and the biconvex lens A10 is 36.4438 mm.
[0055] In this embodiment, the glass refractive index N1 and dispersion coefficient V1 of the negative meniscus lens A1 and the glass refractive index N2 and dispersion coefficient V2 of the biconvex lens A2 satisfy the following relationships: 2.0 > N1 > N2 > 1.0, V1 ≥ 35, V2 ≥ 75. Preferably, the glass refractive index N1 of the negative meniscus lens A1 is 1.80610, the dispersion coefficient V1 is 40.95, the glass refractive index N2 of the biconvex lens A2 is 1.49700, and the dispersion coefficient V2 is 81.61.
[0056] In this embodiment, the glass refractive index N2 and dispersion coefficient V2 of the biconvex lens A2 and the glass refractive index N3 and dispersion coefficient V3 of the biconvex lens A3 satisfy the following relationships: 1.8 > N2 > N3 > 1.0, V2 ≥ 75, V3 ≥ 85. Preferably, the glass refractive index N2 of the biconvex lens A2 is 1.49700, the dispersion coefficient V2 is 81.61; the glass refractive index N3 of the biconvex lens A3 is 1.43780, and the dispersion coefficient V3 is 94.52.
[0057] In this embodiment, the glass refractive index N6 and dispersion coefficient V6 of the biconvex lens A6 and the glass refractive index N7 and dispersion coefficient V7 of the biconcave lens A7 satisfy the following relationships: 2.5 > N6 > N7 > 1.0, V6 ≥ 15, V7 ≥ 35.
[0058] In this embodiment, the glass refractive index N8 and dispersion coefficient V8 of the biconcave lens A8 and the glass refractive index N9 and dispersion coefficient V9 of the biconvex lens A9 satisfy the following relationships: 1.0 < N8 < N9 < 2.5, V8 ≥ 35, V9 ≥ 15. Preferably, the glass refractive index N8 of the biconcave lens A8 is 1.84666, the dispersion coefficient V8 is 23.78; the glass refractive index N9 of the biconvex lens A9 is 1.83481, and the dispersion coefficient V9 is 42.71.
[0059] In this embodiment, the parameters of each lens of the lens are shown in Table 1 below.
[0060] Surface Serial Number Type Radius of Curvature mm Thickness mm Material S1 Spherical Surface 135.337 1.800 H - ZLAF52 S2 Spherical Surface 28.422 7.064 H - FK61B S3 Spherical Surface -68.878 1.000 AIR S4 Spherical Surface 27.909 5.951 H - FK95N S5 Spherical Surface -231.323 11.622 AIR S6 Spherical Surface -167.717 3.918 H - LAF4 S7 Spherical Surface -27.596 1.800 H - ZBAF52 S8 Spherical Surface Infinity 1.500 AIR S9 Spherical Surface 251.505 2.744 H - ZF52 S10 Spherical Surface -17.992 1.001 H - ZLAF55C S11 Spherical Surface 14.166 20.150 AIR S12 Spherical Surface -11.309 1.156 H - LAF54 S13 Spherical Surface 13.905 2.268 H - ZF52 S14 Spherical Surface -86.245 7.626 AIR S15 Spherical Surface 14.475 1.716 H - K9L S16 Spherical Surface -11.701 0.500 AIR S17 Spherical Surface 8.179 2.345 H - ZPK1A S18 Spherical Surface -7.407 1.000 H - LAF54 S19 Spherical Surface 8.436 1.000 AIR
[0061] Table 1 In this embodiment, the material parameters of each lens of the lens are shown in Table 2 below.
[0062] Name Refractive Index Nd Dispersion Coefficient Vd Corresponding Lens H - ZLAF52 1.80610 40.95 A1 H - FK61B 1.49700 81.61 A2 H - FK95N 1.43780 94.52 A3 H - LAF4 1.74950 34.99 A4 H - ZBAF52 1.67003 47.20 A5 H - ZF52 1.84666 23.78 A6, A9 H - ZLAF55C 1.83481 42.71 A7 H - LAF54 179952 42.24 A8, A12 H - K9L 1.51680 64.20 A10 H - ZPK1A 1.61800 63.39 A11
[0063] Table 2
[0064] In this embodiment, none of the lenses use aspherical lenses, and they are all spherical lenses that can be simply processed and produced, and the processing difficulty is significantly reduced.
[0065] In this embodiment, the lens can be adapted to a detector with a resolution of 40 million pixels, and the image quality far exceeds that of the high-definition telephoto zoom lenses currently produced on the market.
[0066] The advantages of the present utility model are as follows: the cost and processing difficulty of the telephoto zoom lens are reduced; the lens with telephoto zoom ability can adjust the focal length at 300 mm to 600 mm, the zoom ratio reaches 12 times, the object space resolution reaches 42 line pairs, and at the same time it can be adapted to a 40 million pixel level detector with a pixel size of 2 μm. The lens with telephoto zoom ability uses a variety of materials such as H-FK61B and H-FK95N as lenses, improving and optimizing the chromatic aberration problem.
[0067] If the present utility model discloses or involves components or structural parts that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connected by bolts or screws), or it can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutually fixed connection can also be replaced by an integral structure (for example, manufactured by integral casting process) (except when it is obviously impossible to adopt the integral forming process).
[0068] In addition, the terms used to represent the positional relationship or shape in any of the technical solutions disclosed in the present utility model shall, unless otherwise stated, include states or shapes that are approximate, similar or close to it.
[0069] Any component provided by the present utility model can either be assembled from a plurality of separate components or be a single component manufactured by an integral forming process.
[0070] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them; although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present utility model or make equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present utility model, they should all be covered within the scope of the technical solutions claimed by the present utility model.
Claims
1. A telephoto zoom lens, characterized in that: The optical system of the lens includes a front fixed group, a focusing group, a middle fixed group, a zooming group, a compensating group, and a rear fixed group arranged in sequence from the object space to the image space along the optical axis direction. The front fixed group consists of a negative meniscus lens A1 and a biconvex lens A2, and the negative meniscus lens A1 and the biconvex lens A2 are closely adhered to form a first cemented group G1; the focusing group is a biconvex lens A3; the middle fixed group consists of a positive meniscus lens A4 and a plano-concave lens A5, and the positive meniscus lens A4 and the plano-concave lens A5 are closely adhered to form a second cemented group G2; the zooming group consists of a biconvex lens A6 and a biconcave lens A7, and the biconvex lens A6 and the biconcave lens A7 are closely adhered to form a third cemented group G3; the compensating group consists of a biconcave lens A8 and a biconvex lens A9, and the biconcave lens A8 and the biconvex lens A9 are closely adhered to form a fourth cemented group G4; the rear fixed group consists of a biconvex lens A10, a biconvex lens A11, and a biconcave lens A12, and the biconvex lens A11 and the biconcave lens A12 are closely adhered to form a fifth cemented group G5.
2. The telephoto zoom lens according to claim 1, characterized in that: When the lens is in the high magnification state, the total distance TTL from the object side surface of the first cemented group to the imaging surface satisfies the following relationship with the focal length variable △f when the lens is in the high magnification state and the low magnification state: 2 < TTL / △f < 5.
3. The long-focus zoom lens according to claim 2, characterized in that: When the lens is in the high magnification state, the combined total focal length of the first cemented group G1 and the biconvex lens A3 is f6; the combined total focal length of the second cemented group G2, the third cemented group G3, the fourth cemented group G4, and the biconvex lens A10 is f7, and they satisfy the following relationship: 0.1 < f6 / f7 < 0.3; when the lens is in the low magnification state, the combined total focal length of the first cemented group G1 and the biconvex lens A3 is f8, and the combined total focal length of the second cemented group G2, the third cemented group G3, the fourth cemented group G4, and the biconvex lens A10 is f9, and they satisfy the following relationship: 5.5 < f8 / f9 < 7.
5.
4. A telephoto zoom lens according to claim 1, characterized in that: When the focal length of the lens is ft1 in the high magnification state and the object distance of the lens is D, they satisfy the following relationship: 0.1 < ft1 / D < 0.2; when the object distance of the lens is d, they satisfy the following relationship: 0.1 < ft1 / d < 0.3; when the focal length of the lens is ft2 in the low magnification state and the object distance of the lens is D, they satisfy the following relationship: 0.01 < ft2 / D < 0.1, and when the object distance of the lens is d, they satisfy the following relationship: 0.1 < ft2 / d < 0.
2.
5. The long-focus zoom lens according to claim 4, wherein: The distance TTL on the optical axis from the object side surface of the first cemented group G1 to the imaging surface satisfies the following relationship with the focal length ft1 when the lens is in the high magnification state: 1.0 < TTL / ft1 < 2.5; the distance TTL on the optical axis from the object side surface of the first cemented group G1 to the imaging surface satisfies the following relationship with the focal length ft2 when the lens is in the low magnification state: 2.0 < TTL / ft2 < 4.
0.
6. A telephoto zoom lens according to claim 2, characterized in that: When the lens is in the high magnification state, the combined total focal length of the biconvex lens A3, the second cemented group G2, and the third cemented group G3 is f10, and the combined total focal length of the biconvex lens A10 and the fifth cemented group G5 is f11, and they satisfy the following relationship: 18 < f10 / f11 < 19; When the lens is in the low magnification state, the combined total focal length of the bi-convex lens A3, the second cemented group G2, and the third cemented group G3 is f12, and the combined total focal length of the bi-convex lens A10 and the fifth cemented group G5 is f13, and they satisfy: -5 < f12 / f13 < -3.
7. A telephoto zoom lens according to claim 1, characterized in that: When the lens switches from the low magnification state to the high magnification state, the change value of the air gap on the optical axis between the second cemented group G2 and the third cemented group G3 is ΔD1; when the lens switches from the low magnification state to the high magnification state, the change value of the air gap on the optical axis between the second cemented group G2 and the fourth cemented group G4 is ΔD2, and they satisfy: 3 < |ΔD2 / ΔD1| < 5.
8. A telephoto zoom lens according to claim 1, characterized in that: The focal length f1 of the first cemented group G1 and the focal length f2 of the bi-convex lens A3 satisfy: 6 < f1 / f2 < 8; the shortest object distance of the lens is u, and the focal length of the first cemented group G1 is f1, and they satisfy the following relationship: 0.1 < u / f1 < 1.5; the focal length of the fifth cemented group G5 is f5, and the image distance of the lens is v, and they satisfy the following relationship: -1.5 < f5 / v < -0.5; the focal length of the rear fixed group is f14, and the image circle of the lens is L, and they satisfy the following relationship: 1.0 < f14 / L < 2.
5.
9. A telephoto zoom lens according to claim 1, characterized in that: The focusing group, the zooming group, and the compensating group can all move along the optical axis direction. During the zooming process, the air interval change range between the front fixed group and the focusing group is 1.0000 mm to 10.6218 mm, the air interval change range between the zooming group and the middle fixed group is 1.5000 mm to 26.2761 mm, the air interval change range between the zooming group and the compensating group is 20.1501 mm to 2.0000 mm, and the air interval change range between the compensating group and the rear fixed group is 7.6261 mm to 1.0000 mm; the air interval between the bi-convex lens A10 and the fifth cemented group G5 is 0.5000 mm, the air interval between the first cemented group G1 and the second cemented group G2 is 18.5734 mm, and the air interval between the second cemented group G2 and the bi-convex lens A10 is 36.4438 mm.
10. A telephoto zoom lens according to claim 1, characterized in that: The glass refractive index N1 and dispersion coefficient V1 of the negative meniscus lens A1 and the glass refractive index N2 and dispersion coefficient V2 of the bi-convex lens A2 satisfy the following relationship: 2.0 > N1 > N2 > 1.0, V1 ≥ 35, V2 ≥ 75; the glass refractive index N2 and dispersion coefficient V2 of the bi-convex lens A2 and the glass refractive index N3 and dispersion coefficient V3 of the bi-convex lens A3 satisfy the following relationship: 1.8 > N2 > N3 > 1.0, V2 ≥ 75, V3 ≥ 85; the glass refractive index N6 and dispersion coefficient V6 of the bi-convex lens A6 and the glass refractive index N7 and dispersion coefficient V7 of the bi-concave lens A7 satisfy the following relationship: 2.5 > N6 > N7 > 1.0, V6 ≥ 15, V7 ≥ 35; The glass refractive index N8 and dispersion coefficient V8 of the biconcave lens A8 and the glass refractive index N9 and dispersion coefficient V9 of the biconvex lens A9 satisfy the following relationships: 1.0 < N8 < N9 < 2.5, V8 ≥ 35, V9 ≥ 15.