A large-aperture compact zoom lens

Abstract

A large-aperture compact zoom lens disclosed by the present invention includes a lens body. The direction from the object side to the image side along the optical axis of the lens body is from front to back. The lens body includes a lens barrel, a front fixed group, a zoom group, a compensation group, and a driving device. The front fixed group includes a first lens group with a positive optical power. The zoom group and the compensation group are movably arranged in a cavity along the front-back direction. The zoom group includes a second lens group, a third lens group, and a fourth lens group arranged at intervals from front to back. The compensation group includes a fifth lens group with a positive optical power. The fifth lens group is arranged behind the fourth lens group and is spaced from the fourth lens group. The driving device is drivingly connected to the zoom group and the compensation group. In the present invention, the overall optical length of the large-aperture compact zoom lens is TTL, TTL ≤ 140 mm, FNOw ≤ 1.1, FNOw is the F-number of the minimum focal length, the maximum focal length is Ft, the minimum focal length is Fw, and the zoom ratio Ft / Fw = 17.69, which can meet the use in low-light environments and achieve high imaging quality.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and particularly to a large-aperture compact zoom lens. Background Art

[0002] In the field of security, in the case of reduced environmental illuminance or insufficient ambient light for monitoring, in order to improve the quality of the final image, a large-aperture lens needs to be used under specific circumstances, while taking into account the requirements of volume and zoom. Therefore, the demand for compact large-aperture zoom lenses in the market is increasing day by day. Summary of the Invention

[0003] The main object of the present invention is to provide a large-aperture compact zoom lens, aiming to improve the imaging quality in low-light environments while reducing the volume of the lens.

[0004] To achieve the above object, the large-aperture compact zoom lens proposed by the present invention includes a lens body. The direction from the object side to the image side along the optical axis of the lens body is from front to back;

[0005] The lens body includes:

[0006] A lens barrel arranged along the front-back direction, and a cavity is formed inside the lens barrel;

[0007] A front fixed group including a first lens group with positive optical power;

[0008] A zoom group movably arranged in the cavity along the front-back direction, including a second lens group, a third lens group, and a fourth lens group arranged at intervals from front to back;

[0009] A compensation group movably arranged in the cavity along the front-back direction, including a fifth lens group with positive optical power. The fifth lens group is arranged behind the fourth lens group and is spaced from the fourth lens group; and,

[0010] A driving device drivingly connected to the zoom group and the compensation group;

[0011] Wherein, the overall optical length of the large-aperture compact zoom lens is TTL, and TTL ≤ 140 mm;

[0012] The F-number at the minimum focal length of the large-aperture compact zoom lens is FNOw, and FNOw ≤ 1.1;

[0013] The maximum focal length of the large-aperture compact zoom lens is Ft, the minimum focal length of the large-aperture compact zoom lens is Fw, and the zoom ratio of the large-aperture compact zoom lens is Ft / Fw, and Ft / Fw = 17.69.

[0014] Optionally, the first lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in sequence from front to back;

[0015] The second lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged in sequence from front to back;

[0016] The third lens group includes an eleventh lens and a twelfth lens arranged in sequence from front to back;

[0017] The fourth lens group includes a thirteenth lens, a fourteenth lens, and a fifteenth lens arranged in sequence from front to back;

[0018] The fifth lens group includes a sixteenth lens, a seventeenth lens, an eighteenth lens, a nineteenth lens, a twentieth lens, and a twenty - first lens arranged in sequence from front to back.

[0019] Optionally, the first lens, the third lens, the fifth lens, the sixth lens, the ninth lens, the eleventh lens, the twelfth lens, the fifteenth lens, and the seventeenth lens are all meniscus lenses with the convex surface facing the object side;

[0020] The second lens, the fourth lens, and the thirteenth lens are all plano - convex lenses;

[0021] The seventh lens, the fourteenth lens, the eighteenth lens, the twentieth lens, and the twenty - first lens are all biconvex lenses;

[0022] The eighth lens is a concave - plano lens;

[0023] The tenth lens and the sixteenth lens are both biconcave lenses;

[0024] The nineteenth lens is a plano - concave lens.

[0025] Optionally, the first lens and the second lens are doublet lenses;

[0026] The seventh lens and the eighth lens are doublet lenses;

[0027] The eleventh lens and the twelfth lens are doublet lenses;

[0028] The sixteenth lens, the seventeenth lens, and the eighteenth lens are triplet lenses;

[0029] The nineteenth lens and the twentieth lens are doublet lenses;

[0030] The sixth lens, the eighth lens, the eleventh lens, the thirteenth lens, the fourteenth lens, the nineteenth lens, and the twentieth lens are all aspherical lenses.

[0031] Optionally, the optical power of the first lens group is φ G1 , the optical power of the second lens group is φ G2 , the optical power of the third lens group is φ G3 , the optical power of the fourth lens group is φ G4 , the optical power of the fifth lens group is φ G5 , satisfying the following relational expressions: 0.017 ≤ φ G1 ≤ 0.0178, -0.113 ≤ φ G2 ≤ -0.114, 0.014 ≤ φ G3 ≤ 0.015, 0.033 ≤ φ G4 ≤ 0.035, 0.044 ≤ φ G5 ≤ 0.046.

[0032] Optionally, the lens body further includes a diaphragm, which is disposed in the fourth lens group and fixed between the thirteenth lens and the fourteenth lens so as to be driven by the fourth lens group to move in the front-rear direction.

[0033] Optionally, the first lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in sequence from front to back;

[0034] The second lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged in sequence from front to back;

[0035] The third lens group includes an eleventh lens, a twelfth lens, and a thirteenth lens arranged in sequence from front to back;

[0036] The fourth lens group includes a fourteenth lens, a fifteenth lens, and a sixteenth lens arranged in sequence from front to back;

[0037] The fifth lens group includes a seventeenth lens, an eighteenth lens, a nineteenth lens, a twentieth lens, a twenty-first lens, and a twenty-second lens arranged in sequence from front to back.

[0038] Optionally, the first lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the ninth lens, the twelfth lens, the thirteenth lens, the fifteenth lens, the eighteenth lens, and the twentieth lens are all meniscus lenses with the convex surface facing the object side;

[0039] The second lens, the seventh lens, the eleventh lens, the fourteenth lens, the twenty-first lens, and the twenty-second lens are all biconvex lenses;

[0040] The eighth lens, the tenth lens, the sixteenth lens, and the seventeenth lens are all biconcave lenses;

[0041] The nineteenth lens is a convex plano lens.

[0042] Optionally, the first lens and the second lens are cemented lenses;

[0043] The seventh lens and the eighth lens are cemented lenses;

[0044] The twelfth lens and the thirteenth lens are cemented lenses;

[0045] The seventeenth lens, the eighteenth lens, and the nineteenth lens are triple cemented lenses;

[0046] The twentieth lens and the twenty-first lens are doublet cemented lenses;

[0047] The sixth lens, the eighth lens, the eleventh lens, the fourteenth lens, and the fifteenth lens are all aspherical lenses.

[0048] Optionally, the lens body further includes a diaphragm, the diaphragm is disposed on the front side of the fourth lens group and is fixed relative to the fourth lens group so as to be driven by the fourth lens group to move in the front-back direction.

[0049] In the technical solution of the present invention, the front fixed group, the zoom group, and the compensation group are arranged in sequence along the optical axis of the lens body from the object side to the image side. The front fixed group includes a first lens group with positive optical power. The zoom group includes a second lens group, a third lens group, and a fourth lens group arranged at intervals from front to back. The compensation group includes a fifth lens group with positive optical power. The zoom group and the compensation group can move back and forth under the drive of the driving device, that is, they move relative to each other, so that the focal length of the lens body can be adjusted. The zoom group mainly undertakes the zooming function and can realize continuous zooming of the lens body from the wide-angle end to the telephoto end. The compensation group mainly undertakes the image plane compensation function and can compensate the image plane during the continuous zooming process of the lens body, so as to ensure the imaging quality when the lens body is continuously zooming. Under the combined action of the zoom group and the compensation group, not only the focal length of the lens body is shortened, but also the imaging within the focal length range can be ensured to be clear, thereby reducing the volume of the lens. In this solution, the overall optical length of the large-aperture compact zoom lens is small, the structure is compact, and the overall volume is small. During the actual focusing process, the purpose of zooming can be achieved by changing the relative positions of the zoom group and the compensation group. The large-aperture compact zoom lens realizes target imaging in a large range from a wide-angle wide field of view to a narrow field of view, improves the monitoring performance of the monitoring device, and meets the requirements of high image quality. The large-aperture compact zoom lens has a large aperture at the wide-angle end and can meet the use requirements in low-light environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0051] Figure 1 FIG. 9 is a schematic diagram of the first embodiment of the large-aperture compact zoom lens of the present invention at the minimum focal length;

[0052] Figure 2 is Figure 1 FIG. 15 is a schematic diagram of the large-aperture compact zoom lens at the intermediate focal length;

[0053] Figure 3 is Figure 1 FIG. 21 is a schematic diagram of the large-aperture compact zoom lens at the maximum focal length;

[0054] Figure 4 FIG. 25 is a schematic diagram of the second embodiment of the large-aperture compact zoom lens of the present invention.

[0055] Explanation of the reference numerals in the drawings:

[0056]

[0057] The realization, functional features, and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Specific embodiments

[0058] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0059] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0060] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0061] In the field of security, in the case of reduced environmental illumination or insufficient monitored environmental light, in order to improve the quality of the final image, it is necessary to use a large-aperture lens under specific circumstances, while taking into account the requirements of volume and zoom. Therefore, the demand for compact large-aperture zoom lenses on the market is increasing day by day.

[0062] In view of this, the present invention proposes a large-aperture compact zoom lens. Figures 1 to 3 This is the first embodiment of the large-aperture compact zoom lens provided by the present invention. Figure 4 This is the second embodiment of the large-aperture compact zoom lens provided by the present invention. The overall volume of the present invention is small, and the imaging quality in low-light environments is high. The large-aperture compact zoom lens will be described below with reference to specific drawings.

[0063] Refer to Figures 1 to 4, the large-aperture compact zoom lens 100 includes a lens body. The direction from the object side to the image side along the optical axis of the lens body is from front to back. The lens body includes a lens barrel (not shown in the figure), a front fixed group, a zoom group, a compensation group, and a driving device (not shown in the figure). The lens barrel is arranged in the front-back direction, and a cavity is formed inside the lens barrel. The front fixed group is arranged in the cavity and includes a first lens group 1 with a positive optical power. The zoom group is movably arranged in the cavity in the front-back direction and includes a second lens group 2, a third lens group 3, and a fourth lens group 4 arranged at intervals from front to back. The compensation group is movably arranged in the cavity in the front-back direction and includes a fifth lens group 5 with a positive optical power. The fifth lens group 5 is arranged behind the fourth lens group 4 and is spaced from the fourth lens group 4. The driving device is drivingly connected to the zoom group and the compensation group. The overall optical length of the large-aperture compact zoom lens 100 is TTL, and TTL ≤ 140 mm; the F-number of the large-aperture compact zoom lens 100 is 1.1 to 4, and the F-number at the minimum focal length is FNOw, and FNOw ≤ 1.1; the maximum focal length of the large-aperture compact zoom lens 100 is Ft, the minimum focal length of the large-aperture compact zoom lens 100 is Fw, the zoom ratio of the large-aperture compact zoom lens 100 is Ft / Fw, and Ft / Fw = 17.69.

[0064] In the technical solution of the present invention, the front fixed group, the zoom group, and the compensation group are arranged in sequence along the optical axis of the lens body from the object side to the image side. The front fixed group includes a first lens group 1 with a positive optical power. The zoom group includes a second lens group 2, a third lens group 3, and a fourth lens group 4 arranged at intervals from front to back. The compensation group includes a fifth lens group 5 with a positive optical power. The zoom group and the compensation group can move back and forth under the drive of the driving device, that is, the relative movement between the zoom group and the compensation group enables the focal length of the lens body to be adjusted. The zoom group mainly undertakes the zooming function and can achieve continuous zooming of the lens body from the wide-angle end to the telephoto end. The compensation group mainly undertakes the image plane compensation function and can compensate the image plane during the continuous zooming process of the lens body, thereby ensuring the imaging quality when the lens body is continuously zoomed. Under the combined action of the zoom group and the compensation group, not only the focal length of the lens body is shortened, but also the imaging within the focal length range is ensured to be clear, and further the volume of the lens is reduced. In this solution, the overall optical length of the large-aperture compact zoom lens 100 does not exceed 140 mm, the overall length is small, the structure is compact, and the overall volume is small. During the actual focusing process, the purpose of zooming can be achieved by changing the relative positions of the zoom group and the compensation group. The zoom ratio is 17.69. The large-aperture compact zoom lens 100 realizes target imaging in a large range from a wide-angle wide field of view to a narrow field of view, improves the monitoring performance of the monitoring device, and meets the requirements of high image quality. The large-aperture compact zoom lens 100 has a large aperture at the wide-angle end. The F number of the large-aperture compact zoom lens 100 is 1.1 to 4, and the F number at the minimum focal length is FNOw, and FNOw ≤ 1.1, which can meet the use in low-light environments.

[0065] Please refer to Figures 1 to 3 , in the first embodiment, the first lens group 1 includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15 arranged in sequence from front to back. The second lens group 2 includes a sixth lens 21, a seventh lens 22, an eighth lens 23, a ninth lens 24, and a tenth lens 25 arranged in sequence from front to back. The third lens group 3 includes an eleventh lens 31 and a twelfth lens 32 arranged in sequence from front to back. The fourth lens group 4 includes a thirteenth lens 41, a fourteenth lens 42, and a fifteenth lens 43 arranged in sequence from front to back. The fifth lens group 5 includes a sixteenth lens 51, a seventeenth lens 52, an eighteenth lens 53, a nineteenth lens 54, a twentieth lens 55, and a twenty-first lens 56 arranged in sequence from front to back.

[0066] The first lens 11, the third lens 13, the fifth lens 15, the sixth lens 21, the ninth lens 24, the eleventh lens 31, the twelfth lens 32, the fifteenth lens 43, and the seventeenth lens 52 are all meniscus lenses with the convex surface facing the object side. The second lens 12, the fourth lens 14, and the thirteenth lens 41 are all plano-convex lenses. The seventh lens 22, the fourteenth lens 42, the eighteenth lens 53, the twentieth lens 55, and the twenty-first lens 56 are all biconvex lenses. The eighth lens 23 is a concave-plano lens. The tenth lens 25 and the sixteenth lens 51 are both biconcave lenses. The nineteenth lens 54 is a plano-concave lens.

[0067] The first lens 11 and the second lens 12 are doublet lenses. The seventh lens 22 and the eighth lens 23 are doublet lenses. The eleventh lens 31 and the twelfth lens 32 are doublet lenses. The sixteenth lens 51, the seventeenth lens 52, and the eighteenth lens 53 are triplet lenses. The nineteenth lens 54 and the twentieth lens 55 are doublet lenses. The sixth lens 21, the eighth lens 23, the eleventh lens 31, the thirteenth lens 41, the fourteenth lens 42, the nineteenth lens 54, and the twentieth lens 55 are all aspherical lenses.

[0068] The optical power of the first lens group 1 is φ G1 , the optical power of the second lens group 2 is φ G2 , the optical power of the third lens group 3 is φ G3 , the optical power of the fourth lens group 4 is φ G4 , the optical power of the fifth lens group 5 is φ G5 , satisfying the following relational expressions: 0.017 ≤ φ G1 ≤ 0.0178, -0.113 ≤ φ G2 ≤ -0.114, 0.014 ≤ φ G3 ≤ 0.015, 0.033 ≤ φ G4 ≤ 0.035, 0.044 ≤ φ G5 ≤ 0.046.

[0069] Based on the above parameters, when each of the second lens group 2, the third lens group 3, the fourth lens group 4, and the fifth lens group 5 moves forward and backward, there is an active stroke of approaching and moving away from the adjacent lens group. By adjusting the relative positions among the second lens group 2, the third lens group 3, and the fourth lens group 4 within the zoom group, the focal length of the lens body can be correspondingly changed to adjust the lens body to the required magnification; by adjusting the relative position of the fifth lens group 5 within the lens barrel, the imaging picture of the lens body can be adjusted to the required imaging quality. In this embodiment, the relative movement between the zoom group and the compensation group causes the focal length of the lens to change and ensures that the imaging within this focal length range is clear.

[0070] When designing the lens, the requirements for volume in the security field are taken into consideration. Therefore, on the premise of meeting the volume requirements, the design of the large-aperture compact zoom lens 100 is achieved, with a small optical length and meeting the imaging requirements in low-light environments.

[0071] In order to improve the imaging clarity, in this embodiment, the lens body further includes a diaphragm 6, which is disposed in the fourth lens group 4 and fixed between the thirteenth lens 41 and the fourteenth lens 42, so as to be driven by the fourth lens group 4 to move back and forth. Fixing the diaphragm 6 between the thirteenth lens 41 and the fourteenth lens 42 and moving synchronously back and forth with the fourth lens group 4 can make the imaging have appropriate brightness and clarity during the zooming process of the lens body.

[0072] Specifically, please refer to Tables 1 to 2 below. Tables 1 to 2 provide the specific data for implementing the large-aperture compact zoom lens 100 in the first embodiment.

[0073] Among them, S1 to S39 in Table 1 represent the surface numbers of each optical element. The positive and negative of the radius satisfy the basic symbol rules of optics. Each set of data in the optical material represents the refractive index and Abbe number of the material; the WIDE column in Table 2 represents the values of variable parameters when the lens is at the minimum focal length, the TELE column represents the values of variable parameters when the lens is at the maximum focal length, and the MID column represents the intermediate focal length.

[0074] Table 1

[0075]

[0076]

[0077] Table 2

[0078] Wide MID TELE EFFL 13mm 60mm 230mm FNO 1.1 1.6 4 D9 0.100 17.532 20.440 D18 19.706 4.312 0.200 D21 15.469 8.866 0.170 D28 6.476 8.281 32.290 D37 11.423 14.167 0.100

[0079] In this embodiment, the total optical length TTL satisfies TTL ≤ 140 mm, the focal length f satisfies 13 mm to 230 mm, the zoom ratio Ft / Fw is 17.69, FNO is 1.1 to 4, and FNOw = 1.1.

[0080] Among them, the aspheric parameters satisfy

[0081]

[0082] Among them, z is the sag height of the aspheric surface at different apertures, c is the aspheric curvature, K is the aspheric conic coefficient, r is the normalized radius, and A, B, C, D, E, F, G, H, I, J are the coefficients of each high-order term of the aspheric surface.

[0083] Specifically, please refer to Table 3 below. The sixth lens 21, the eighth lens 23, the eleventh lens 31, the thirteenth lens 41, the fourteenth lens 42, the nineteenth lens 54, and the twentieth lens 55 are aspherical lenses, and Table 3 gives the aspherical coefficients of the aspherical lenses.

[0084] Table 3

[0085]

[0086]

[0087] Please refer to Figure 4 , in the second embodiment, the first lens group 1 includes the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 arranged in sequence from front to back. The second lens group 2 includes the sixth lens 21, the seventh lens 22, the eighth lens 23, the ninth lens 24, and the tenth lens 25 arranged in sequence from front to back. The third lens group 3 includes the eleventh lens 31, the twelfth lens 32, and the thirteenth lens 41 arranged in sequence from front to back. The fourth lens group 4 includes the fourteenth lens 42, the fifteenth lens 43, and the sixteenth lens 51 arranged in sequence from front to back. The fifth lens group 5 includes the seventeenth lens 52, the eighteenth lens 53, the nineteenth lens 54, the twentieth lens 55, the twenty - first lens 56, and the twenty - second lens 57 arranged in sequence from front to back.

[0088] The first lens 11, the third lens 13, the fourth lens 14, the fifth lens 15, the sixth lens 21, the ninth lens 24, the twelfth lens 32, the thirteenth lens 41, the fifteenth lens 43, the eighteenth lens 53, and the twentieth lens 55 are all meniscus lenses with the convex surface facing the object side. The second lens 12, the seventh lens 22, the eleventh lens 31, the fourteenth lens 42, the twenty - first lens 56, and the twenty - second lens 57 are all biconvex lenses. The eighth lens 23, the tenth lens 25, the sixteenth lens 51, and the seventeenth lens 52 are all biconcave lenses. The nineteenth lens 54 is a plano - convex lens.

[0089] The first lens 11 and the second lens 12 are cemented lenses. The seventh lens 22 and the eighth lens 23 are cemented lenses. The twelfth lens 32 and the thirteenth lens 41 are cemented lenses. The seventeenth lens 52, the eighteenth lens 53, and the nineteenth lens 54 are triple - cemented lenses. The twentieth lens 55 and the twenty - first lens 56 are doublet - cemented lenses. The sixth lens 21, the eighth lens 23, the eleventh lens 31, the fourteenth lens 42, and the fifteenth lens 43 are all aspherical lenses.

[0090] It should be noted that in this embodiment, the lens body is also provided with a diaphragm 6. The diaphragm 6 is arranged on the front side of the fourth lens group 4 and is fixed relative to the fourth lens group 4 so as to be driven by the fourth lens group 4 to move in the front-rear direction. Fixing the diaphragm 6 to the fourth lens group 4 and moving synchronously with the fourth lens group 4 in the front-rear direction can make the imaging have appropriate brightness and clarity during the zooming process of the lens body.

[0091] When each of the second lens group 2, the third lens group 3, the fourth lens group 4, and the fifth lens group 5 moves in the front-rear direction, there is an active stroke of approaching and separating from the adjacent lens group. By adjusting the relative positions among the second lens group 2, the third lens group 3, and the fourth lens group 4 within the varifocal group, the focal length of the lens body can be correspondingly changed to adjust the lens body to the required magnification; by adjusting the relative position of the fifth lens group 5 within the lens barrel, the imaging picture of the lens body can be adjusted to the required imaging quality. In this embodiment, the relative movement between the varifocal group and the compensation group

[0092] Specifically, please refer to Tables 4 to 5 below. Tables 4 to 5 provide the specific data for realizing the large-aperture compact zoom lens 100 in the second embodiment.

[0093] Among them, S1 to S41 in Table 4 represent the surface numbers of each optical element. The positive and negative of the radius satisfy the basic symbol rules of optics. Each set of data in the optical material represents the refractive index and Abbe number of the material; the WIDE column in Table 5 represents the values of the variable parameters when the lens is at the minimum focal length, the TELE column represents the values of the variable parameters when the lens is at the maximum focal length, and the MID column represents a certain focal length between the maximum focal length and the minimum focal length.

[0094] Table 4

[0095]

[0096]

[0097] Table 5

[0098]

[0099]

[0100] In this embodiment, the overall optical length TTL satisfies TTL ≤ 140 mm, the focal length f satisfies 13 mm to 230 mm, the zoom ratio Ft / Fw is 17.69, FNO is 1.0 to 4, and FNOw = 1.0.

[0101] Among them, the aspheric parameters satisfy

[0102]

[0103] Among them, z is the sag height of the aspheric surface at different apertures, c is the curvature of the aspheric surface, K is the conic coefficient of the aspheric surface, r is the normalized radius, and A, B, C, D, E, F, G, H, I, J are the coefficients of each high-order term of the aspheric surface.

[0104] Specifically, please refer to Table 6 below. The sixth lens 21, the eighth lens 23, the eleventh lens 31, the fourteenth lens 42, and the fifteenth lens 43 are all aspheric lenses. Table 6 gives the aspheric coefficients of all surfaces of the aspheric lenses.

[0105] Table 6

[0106]

[0107]

[0108] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A large aperture compact zoom lens, characterized in that, It includes a lens body. The direction from the object side to the image side along the optical axis of the lens body is from front to back. The lens body includes: A lens barrel arranged along the front-back direction, and a cavity is formed inside the lens barrel. A front fixed group arranged inside the cavity, including a first lens group with a positive optical power. A zoom group movably arranged inside the cavity along the front-back direction, including a second lens group, a third lens group, and a fourth lens group arranged at intervals from front to back. A compensation group movably arranged inside the cavity along the front-back direction, including a fifth lens group with a positive optical power. The fifth lens group is arranged behind the fourth lens group and is spaced from the fourth lens group; and A driving device drivingly connected to the zoom group and the compensation group. Wherein, the overall optical length of the large-aperture compact zoom lens is TTL, and TTL ≤ 140 mm. The F-number at the minimum focal length of the large-aperture compact zoom lens is FNOw, and FNOw ≤ 1.

1. The maximum focal length of the large-aperture compact zoom lens is Ft, the minimum focal length of the large-aperture compact zoom lens is Fw, and the zoom ratio of the large-aperture compact zoom lens is Ft / Fw, and Ft / Fw = 17.

69.

2. The large-aperture compact zoom lens according to claim 1, characterized in that, The first lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in sequence from front to back. The second lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged in sequence from front to back. The third lens group includes an eleventh lens and a twelfth lens arranged in sequence from front to back. The fourth lens group includes a thirteenth lens, a fourteenth lens, and a fifteenth lens arranged in sequence from front to back. The fifth lens group includes a sixteenth lens, a seventeenth lens, an eighteenth lens, a nineteenth lens, a twentieth lens, and a twenty-first lens arranged in sequence from front to back.

3. The large-aperture compact zoom lens according to claim 2, wherein The first lens, the third lens, the fifth lens, the sixth lens, the ninth lens, the eleventh lens, the twelfth lens, the fifteenth lens, and the seventeenth lens are all meniscus lenses with the convex surface facing the object side. The second lens, the fourth lens, and the thirteenth lens are all plano-convex lenses. The seventh lens, the fourteenth lens, the eighteenth lens, the twentieth lens, and the twenty-first lens are all biconvex lenses. The eighth lens is a plano-concave lens. The tenth lens and the sixteenth lens are all biconcave lenses. The nineteenth lens is a plano-concave lens.

4. The large-aperture compact zoom lens according to claim 3, wherein, The first lens and the second lens are doublet lenses. The seventh lens and the eighth lens are doublet lenses. The eleventh lens and the twelfth lens are doublet lenses. The sixteenth lens, the seventeenth lens, and the eighteenth lens are triplet lenses. The nineteenth lens and the twentieth lens are doublet lenses. The sixth lens, the eighth lens, the eleventh lens, the thirteenth lens, the fourteenth lens, the nineteenth lens, and the twentieth lens are all aspherical lenses.

5. The large-aperture compact zoom lens according to claim 2, characterized in that The optical power of the first lens group is φ G1 , the optical power of the second lens group is φ G2 , the optical power of the third lens group is φ G3 , the optical power of the fourth lens group is φ G4 , the optical power of the fifth lens group is φ G5 , satisfying the following relational expressions: 0.017 ≤ φ G1 ≤ 0.0178, -0.113 ≤ φ G2 ≤ -0.114, 0.014 ≤ φ G3 ≤ 0.015, 0.033 ≤ φ G4 ≤ 0.035, 0.044 ≤ φ G5 ≤ 0.

046.

6. The large-aperture compact zoom lens according to any one of claims 2 to 5, characterized in that, The lens body further includes a diaphragm, which is disposed in the fourth lens group and fixed between the thirteenth lens and the fourteenth lens, so as to be driven by the fourth lens group to move in the front-rear direction.

7. The large-aperture compact zoom lens according to claim 1, characterized in that, The first lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in sequence from front to back; The second lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, and a tenth lens arranged in sequence from front to back; The third lens group includes an eleventh lens, a twelfth lens, and a thirteenth lens arranged in sequence from front to back; The fourth lens group includes a fourteenth lens, a fifteenth lens, and a sixteenth lens arranged in sequence from front to back; The fifth lens group includes a seventeenth lens, an eighteenth lens, a nineteenth lens, a twentieth lens, a twenty-first lens, and a twenty-second lens arranged in sequence from front to back.

8. The large-aperture compact zoom lens according to claim 7, characterized in that The first lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the ninth lens, the twelfth lens, the thirteenth lens, the fifteenth lens, the eighteenth lens, and the twentieth lens are all meniscus lenses with convex surfaces facing the object side; The second lens, the seventh lens, the eleventh lens, the fourteenth lens, the twenty-first lens, and the twenty-second lens are all biconvex lenses; The eighth lens, the tenth lens, the sixteenth lens, and the seventeenth lens are all biconcave lenses; The nineteenth lens is a plano-convex lens.

9. The large-aperture compact zoom lens according to claim 8, characterized in that, The first lens and the second lens are cemented lenses; The seventh lens and the eighth lens are cemented lenses; The twelfth lens and the thirteenth lens are cemented lenses; The seventeenth lens, the eighteenth lens, and the nineteenth lens are triple-cemented lenses; The twentieth lens and the twenty-first lens are double-cemented lenses; The sixth lens, the eighth lens, the eleventh lens, the fourteenth lens, and the fifteenth lens are all aspherical lenses.

10. The large-aperture compact zoom lens according to any one of claims 7 to 9, characterized in that, The lens body further includes a diaphragm, which is disposed on the front side of the fourth lens group and fixed relative to the fourth lens group, so as to be driven by the fourth lens group to move in the front-rear direction.

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