Zoom lens

Abstract

The present invention relates to a zoom lens, which includes a compensation group (G1) with a negative optical power, a first fixed group (G2) with a positive optical power, and a variable magnification group (G3) with a positive optical power, arranged in sequence from the object side to the image side along the optical axis. It also includes a second fixed group (G4) located on the image side of the variable magnification group (G3). During the variable magnification process, the relative positions of the first fixed group (G2) and the second fixed group (G4) with respect to the image plane are fixed, and the compensation group (G1) and the variable magnification group (G3) can move along the optical axis. The zoom lens of the present invention has the characteristics of a super large aperture, a large target surface, and low cost.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and particularly to a zoom lens. Background Art

[0002] Zoom lenses have the characteristic of variable focal length and can meet the requirements of diverse monitoring scenarios, so they have received extensive attention in the security monitoring market. The rapid popularization and development of security monitoring have also put forward higher requirements for the image acquisition function of lenses. A zoom lens with a powerful image acquisition function needs to ensure large-aperture zoom within the full focal length range while meeting the conditions of high resolution and large image circle. In this way, even when the external supplementary light is insufficient, high-definition images can still be captured. To expand the application scenarios of such lenses, the zoom lens also needs to have the performance of not defocusing at low temperatures from -40°C to high temperatures of 80°C. Lenses that take into account the above characteristics will have great application prospects. Therefore, the issue of their manufacturing cost also needs to be considered. However, the zoom lenses in the prior art generally cannot meet the above requirements. Summary of the Invention

[0003] The purpose of the present invention is to provide a zoom lens.

[0004] To achieve the above object of the invention, the present invention provides a zoom lens, which includes a compensation group with negative optical power, a first fixed group with positive optical power, and a variable magnification group with positive optical power arranged in sequence from the object side to the image side along the optical axis. It further includes a second fixed group located on the image side of the variable magnification group. During the zooming process, the relative positions of the first fixed group and the second fixed group with respect to the image plane are fixed, and the compensation group and the variable magnification group can move along the optical axis.

[0005] According to one aspect of the present invention, the second fixed group has positive optical power.

[0006] According to one aspect of the present invention, the compensation group includes a first lens with negative optical power, a second lens with negative optical power, and a third lens with positive optical power arranged in sequence from the object side to the image side.

[0007] According to one aspect of the present invention, the first lens is a convex-concave or concave-concave lens, the second lens is a convex-concave lens in the paraxial region, and the third lens is a convex-concave lens in the paraxial region.

[0008] According to one aspect of the present invention, the first fixed group includes a fourth lens with positive optical power.

[0009] According to one aspect of the present invention, the fourth lens is a convex-concave lens in the paraxial region.

[0010] According to one aspect of the present invention, the variable magnification group includes a fifth lens with a positive focal power, a sixth lens with a negative focal power, a seventh lens with a positive focal power, an eighth lens with a negative focal power, a ninth lens with a positive focal power, and a tenth lens with a positive focal power, which are arranged in sequence from the object side to the image side;

[0011] The sixth lens and the seventh lens are cemented together to form a cemented lens group.

[0012] According to one aspect of the present invention, the fifth lens is a convex-convex lens, the sixth lens is a convex-concave lens, the seventh lens is a convex-concave or convex-convex lens, the eighth lens is a convex-concave lens in the paraxial region, the ninth lens is a convex-convex or concave-convex lens in the paraxial region, and the tenth lens is a convex-concave lens in the paraxial region.

[0013] According to one aspect of the present invention, the second fixed group includes an eleventh lens with a positive focal power.

[0014] According to one aspect of the present invention, the eleventh lens is a convex-convex or convex-concave lens in the paraxial region.

[0015] According to one aspect of the present invention, the zoom lens further includes a position-fixed diaphragm, and the diaphragm is located between the compensation group and the first fixed group or between the first fixed group and the variable magnification group.

[0016] According to one aspect of the present invention, the diameter SD_STO of the diaphragm and the distance TTL_W from the front surface vertex of the first lens to the image plane at the wide-angle end of the zoom lens satisfy the following relationship: 0.08 < SD_STO / TTL_W < 0.20.

[0017] According to one aspect of the present invention, the focal length F4 of the fourth lens and the focal length Fw of the zoom lens at the wide-angle end satisfy the following relationship: 10.00 < |F4 / Fw| < 35.00.

[0018] According to one aspect of the present invention, the focal length F11 of the eleventh lens and the focal length Fw of the zoom lens at the wide-angle end satisfy the following relationship: 12.00 < |F11 / Fw|.

[0019] According to one aspect of the present invention, the focal length FⅠ of the compensation group and the focal length FⅢ of the variable magnification group satisfy the following relationship: 0.70 ≤ |FⅠ / FⅢ| ≤ 0.90.

[0020] According to one aspect of the present invention, the distance ΔD that the compensation group moves from the wide-angle end to the telephoto end of the zoom lens and the distance TTL_W from the front surface vertex of the first lens to the image plane at the wide-angle end of the zoom lens satisfy the following relationship: 0.11 < ΔD / TTL_W < 0.18.

[0021] According to one aspect of the present invention, the focal length F5 of the fifth lens and the focal length FⅢ of the variable magnification group satisfy the following relationship: 0.95 < F5 / FⅢ < 1.30.

[0022] According to one aspect of the present invention, the focal length FB of the cemented lens group in the variable magnification group and the focal length FⅢ of the variable magnification group satisfy the following relationship: 2.50 < |FB / FⅢ| < 18.00.

[0023] According to one aspect of the present invention, the Abbe number vd6 of the sixth lens and the Abbe number vd7 of the seventh lens satisfy the following relationship: 22 < |vd7 - vd6| < 66.

[0024] According to one aspect of the present invention, the fifth lens is an aspherical glass lens, and its refractive index nd5 and Abbe number vd5 respectively satisfy the following conditions: 1.55 < nd5 < 1.85; 40 ≤ vd5 ≤ 70.

[0025] According to one aspect of the present invention, the second lens, the eighth lens, the ninth lens and the eleventh lens are plastic aspherical lenses, and the third lens, the fourth lens and the tenth lens are spherical or aspherical lenses.

[0026] According to one aspect of the present invention, the focal length F8 of the eighth lens, the focal length F9 of the ninth lens, the focal length F10 of the tenth lens and the focal length FⅢ of the variable magnification group respectively satisfy the following relationships: 2.00 < |F8 / FⅢ| < 5.00; 1.00 < F9 / FⅢ < 3.00; 1.50 < F10 / FⅢ.

[0027] According to the concept of the present invention, a zoom lens with a super large aperture, a large target surface and low cost is provided.

[0028] According to one solution of the present invention, the eleventh lens independently forms another fixed group, which is more conducive to improving the imaging quality of the large target surface lens and correcting aberration.

[0029] According to one solution of the present invention, by reasonably setting the relationship between the aperture diameter and the distance from the front surface vertex of the first lens to the image plane at the wide-angle end of the zoom lens, the fixed large aperture ensures a large entrance pupil diameter within the entire focal length range, which is conducive to realizing large aperture zoom.

[0030] According to one solution of the present invention, by reasonably setting the relationship between the focal length of the fourth lens and the focal length of the zoom lens at the wide-angle end, it is beneficial to reduce the ray height after the light passes through the fixed lens group and realize large aperture zoom.

[0031] According to one solution of the present invention, by reasonably setting the relationship between the focal length of the eleventh lens and the focal length of the zoom lens at the wide-angle end, more emphasis is placed on correcting aberrations to ensure higher imaging quality under a large target surface.

[0032] According to one solution of the present invention, by reasonably setting the relationship between the focal length of the compensation group and the focal length of the zoom group, light can be better transmitted, which is beneficial to better focusing and ensuring imaging quality during the zooming process.

[0033] According to one scheme of the present invention, by reasonably setting the relationship between the distance that the compensation group moves from the wide-angle end to the telephoto end of the zoom lens and the distance from the front surface vertex of the first lens to the image plane of the zoom lens at the wide-angle end, a large zoom ratio can be achieved with a smaller group interval change in the process of zooming from the wide-angle end to the telephoto end, which is conducive to achieving an ultra-large aperture while compressing the total length of the lens.

[0034] According to one solution of the present invention, by reasonably setting the relationship between the focal length of the fifth lens and the focal length of the zoom group, it is beneficial to improve the light transmission between the groups, and can achieve as large a zoom ratio as possible under a certain total length condition, which is beneficial to achieving a large aperture at the telephoto end and better ensuring the imaging quality at the entire focal length.

[0035] According to one solution of the present invention, by reasonably setting the relationship between the focal length of the cemented lens group in the zoom group and the focal length of the zoom group, the transmittance of light can be further improved, and the light can be further converged, which is beneficial to high-definition imaging at a large aperture.

[0036] According to one solution of the present invention, by reasonably setting the relationship between the Abbe number of the sixth lens and the Abbe number of the seventh lens, the spherical aberration and chromatic aberration of the system can be corrected, thereby ensuring the sharpness of the lens imaging.

[0037] According to one solution of the present invention, the fifth lens is set as an aspherical glass lens, which is beneficial to correcting high-order aberrations. In addition, by properly setting its refractive index and Abbe number, it is beneficial to correct chromatic aberration, thereby achieving full-focal-length large-aperture zoom.

[0038] According to one solution of the present invention, by properly configuring aspherical and spherical lenses, various aberrations of the system can be well corrected to improve the resolution of the lens and achieve high-definition resolution. In addition, by cleverly matching glass and plastic lenses, the back focus drift of the lens under high and low temperature conditions can be perfectly compensated, ensuring clear imaging of the lens under extreme temperature conditions.

[0039] According to one solution of the present invention, by reasonably setting the relationship between the focal length of the eighth lens, the focal length of the ninth lens, the focal length of the tenth lens and the focal length of the zoom group, it is beneficial to correct aberrations and can effectively ensure that the zoom lens is not out of focus under high and low temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic structural diagram of the wide-angle end of the zoom lens showing the first embodiment of the present invention;

[0041] Figure 2 Schematic structural diagram of the telephoto end of the zoom lens showing the first embodiment of the present invention;

[0042] Figure 3 Schematic visible light RAY FAN diagram of the wide-angle end of the zoom lens showing the first embodiment of the present invention;

[0043] Figure 4 Schematic visible light RAY FAN diagram of the telephoto end of the zoom lens showing the first embodiment of the present invention;

[0044] Figure 5 Schematic structural diagram of the wide-angle end of the zoom lens showing the second embodiment of the present invention;

[0045] Figure 6 Schematic structural diagram of the telephoto end of the zoom lens showing the second embodiment of the present invention;

[0046] Figure 7 Schematic visible light RAY FAN diagram of the wide-angle end of the zoom lens showing the second embodiment of the present invention;

[0047] Figure 8 Schematic visible light RAY FAN diagram of the telephoto end of the zoom lens showing the second embodiment of the present invention;

[0048] Figure 9 Schematic structural diagram of the wide-angle end of the zoom lens showing the third embodiment of the present invention;

[0049] Figure 10 Schematic structural diagram of the telephoto end of the zoom lens showing the third embodiment of the present invention;

[0050] Figure 11 Schematic visible light RAY FAN diagram of the wide-angle end of the zoom lens showing the third embodiment of the present invention;

[0051] Figure 12 Schematic visible light RAY FAN diagram of the telephoto end of the zoom lens showing the third embodiment of the present invention;

[0052] Figure 13 Schematic structural diagram of the wide-angle end of the zoom lens showing the fourth embodiment of the present invention;

[0053] Figure 14Schematic structural diagram of the telephoto end of the zoom lens according to the fourth embodiment of the present invention;

[0054] Figure 15 Schematic visible light RAY FAN diagram of the wide-angle end of the zoom lens according to the fourth embodiment of the present invention;

[0055] Figure 16 Schematic visible light RAY FAN diagram of the telephoto end of the zoom lens according to the fourth embodiment of the present invention. Detailed implementation manners

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required for use in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other accompanying drawings can be obtained based on these drawings without creative efforts.

[0057] When describing the embodiments of the present invention, the orientation or positional relationships expressed by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" are based on the orientation or positional relationships shown in the relevant accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description, 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. Therefore, the above terms should not be construed as limiting the present invention.

[0058] The present invention will be described in detail below with reference to the accompanying drawings and specific implementation manners. The implementation manners cannot be elaborated one by one here, but the implementation manners of the present invention are not limited to the following implementation manners.

[0059] See Figure 1 , the zoom lens of the present invention includes a compensation group G1 with a negative optical power, a first fixed group G2 with a positive optical power, a variable magnification group G3 with a positive optical power, and a second fixed group G4 with a positive optical power, which are arranged in sequence along the optical axis from the object side to the image side. During the zooming process, the relative positions of the first fixed group G2 and the second fixed group G4 with respect to the image plane are fixed, and the compensation group G1 and the variable magnification group G3 can move along the optical axis. Thus, the zoom lens of the present invention has the performance of a super large aperture, a large target surface, and low cost.

[0060] In the present invention, the compensation group G1 includes a first lens L1 with a negative focal power, a second lens L2 with a negative focal power, and a third lens L3 with a positive focal power, which are arranged in sequence from the object side to the image side. The first lens L1 is a convex-concave or concave-concave lens, the second lens L2 is a convex-concave lens in the paraxial region, and the third lens L3 is a convex-concave lens in the paraxial region. The first fixed group G2 includes a fourth lens L4 with a positive focal power, and the fourth lens L4 is a convex-concave lens in the paraxial region. The zoom group G3 includes a fifth lens L5 with a positive focal power, a sixth lens L6 with a negative focal power, a seventh lens L7 with a positive focal power, an eighth lens L8 with a negative focal power, a ninth lens L9 with a positive focal power, and a tenth lens L10 with a positive focal power, which are arranged in sequence from the object side to the image side. Among them, the sixth lens L6 and the seventh lens L7 are cemented to form a cemented lens group. The fifth lens L5 is a convex-convex lens, the sixth lens L6 is a convex-concave lens, the seventh lens L7 is a convex-concave or convex-convex lens, the eighth lens L8 is a convex-concave lens in the paraxial region, the ninth lens L9 is a convex-convex or convex-concave lens in the paraxial region, and the tenth lens L10 is a convex-concave lens in the paraxial region. The second fixed group G4 includes an eleventh lens L11 with a positive focal power, and the eleventh lens L11 is a convex-convex or convex-concave lens in the paraxial region. In addition, the zoom lens of the present invention further includes a fixed aperture STO, and the aperture STO is located between the compensation group G1 and the first fixed group G2 or between the first fixed group G2 and the zoom group G3.

[0061] In the present invention, the diameter SD_STO of the aperture STO and the distance TTL_W from the front surface vertex of the first lens L1 to the image plane at the wide-angle end of the zoom lens satisfy the following relationship: 0.08 < SD_STO / TTL_W < 0.20. In this way, the larger aperture of the fixed aperture STO ensures a larger entrance pupil diameter within the entire focal length range, which is beneficial to achieving large-aperture zoom.

[0062] In the present invention, the focal length F4 of the fourth lens L4 and the focal length Fw of the zoom lens at the wide-angle end satisfy the following relationship: 10.00 < |F4 / Fw| < 35.00. This distribution method of the focal power between groups is beneficial to reducing the ray height after the light passes through the fixed lens group, and achieving large-aperture zoom.

[0063] In the present invention, the focal length F11 of the eleventh lens L11 and the focal length Fw of the zoom lens at the wide-angle end satisfy the following relationship: 12.00 < |F11 / Fw|. This distribution method of the focal power between groups focuses more on correcting aberrations and ensuring higher imaging quality under a large target surface.

[0064] In the present invention, the focal length FⅠ of the compensation group G1 and the focal length FⅢ of the zoom group G3 satisfy the following relationship: 0.70 ≤ |FⅠ / FⅢ| ≤ 0.90. This distribution method of the focal power between groups can better transmit light, which is beneficial to better focusing during the zoom process and ensuring imaging quality.

[0065] In the present invention, the distance ΔD that the compensation group G1 moves from the wide-angle end to the telephoto end of the zoom lens and the distance TTL_W from the front surface vertex of the first lens L1 to the image plane at the wide-angle end of the zoom lens satisfy the following relationship: 0.11 < ΔD / TTL_W < 0.18. In this way, during the process of zooming from the wide-angle end to the telephoto end, a large zoom ratio can be achieved with a small change in the group interval, which is beneficial to achieving a super large aperture while compressing the total length of the lens.

[0066] In the present invention, the focal length F5 of the fifth lens L5 and the focal length FⅢ of the varifocal group G3 satisfy the following relationship: 0.95 < F5 / FⅢ < 1.30. This distribution relationship of the optical power is beneficial to improving the light transmission between groups, enabling a large zoom ratio to be achieved as much as possible under a certain total length condition, which is beneficial to achieving a large aperture at the telephoto end and better ensuring the imaging quality of the entire focal length.

[0067] In the present invention, the focal length FB of the cemented lens group in the varifocal group G3 and the focal length FⅢ of the varifocal group G3 satisfy the following relationship: 2.50 < |FB / FⅢ| < 18.00. In this way, this distribution method of the optical power further improves the light transmission, making the light converge further, which is beneficial to high-definition imaging under a large aperture.

[0068] In the present invention, the Abbe number vd6 of the sixth lens L6 and the Abbe number vd7 of the seventh lens L7 satisfy the following relationship: 22 < |vd7 - vd6| < 66. In this way, by reasonably configuring the Abbe number combination of the cemented lenses, the spherical aberration and chromatic aberration of the system are corrected, ensuring the sharpness of the lens imaging.

[0069] In the present invention, the fifth lens L5 is an aspherical glass lens, and its refractive index nd5 and Abbe number vd5 respectively satisfy the following conditions: 1.55 < nd5 < 1.85; 40 ≤ vd5 ≤ 70. It can be seen that the fifth lens L5 of the present invention adopts an aspherical glass lens, which is beneficial to correcting high-order aberrations. And by restricting the ranges of nd and vd, it is beneficial to correcting chromatic aberration, thereby achieving a large aperture zoom for the entire focal length.

[0070] In the present invention, the second lens L2, the eighth lens L8, the ninth lens L9, and the eleventh lens L11 are plastic aspherical lenses, and the third lens L3, the fourth lens L4, and the tenth lens L10 are spherical or aspherical lenses. In this way, by reasonably configuring the aspherical and spherical lenses, various aberrations of the system are well corrected, thereby improving the resolution of the lens and achieving high-definition resolving power. Additionally, by cleverly matching the glass and plastic lenses, the back focus drift of the lens at high and low temperatures is perfectly compensated, ensuring clear imaging of the lens under extreme temperature conditions.

[0071] In the present invention, the focal length F8 of the eighth lens L8, the focal length F9 of the ninth lens L9, the focal length F10 of the tenth lens L10, and the focal length FⅢ of the varifocal group G3 respectively satisfy the following conditions: 2.00 < |F8 / FⅢ| < 5.00; 1.00 < F9 / FⅢ < 3.00; 1.50 < F10 / FⅢ. This combination relationship of positive and negative optical powers is beneficial to aberration correction and effectively ensures that the zoom lens is not defocused under high and low temperature conditions.

[0072] In summary, for the zoom lens of the present invention, through a reasonable combination of optical powers, it is possible to achieve a super large aperture throughout the entire zoom range from the wide-angle end to the telephoto end within a short stroke. Therefore, even under weak light conditions, high-definition image acquisition can be achieved. Moreover, the present invention adopts a reasonable combination of glass lenses and plastic lenses. With fewer glass lenses used, the performance of the system is still guaranteed, while the production cost is greatly reduced. Through specific material selection of the lenses and reasonable combination of optical powers, the system can still ensure good resolution at high temperature of 80 °C and low temperature of -40 °C, and is not defocused under high and low temperatures.

[0073] The following details the zoom lens of the present invention in four sets of embodiments. In the following embodiments, the surfaces of each lens and the aperture stop STO are represented by 1, 2,..., N. The cemented surface of the cemented lens group is denoted as the first surface, and the image plane is denoted as IMA. The aspherical lens surface profile satisfies the following formula:

[0074] Z = cy 2 / {1 + [1 - (1 + k)c 2 y 2 1 / 2}+ a4y 4 + a6y 6 + a8y 8 + a 10 y 10 + a 12 y 12 + a 14 y 14 + a 16 y 16 ;

[0075] where Z is the axial distance from the vertex of the curved surface at a position along the optical axis and perpendicular to the optical axis with a height of h; c represents the curvature at the vertex of the aspherical surface; y is the radial coordinate of the aspherical lens; k is the conic coefficient; a4, a6, a8, a 10 , a 12 , a 14 , a 16 respectively represent the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order aspherical coefficients.

[0076] ​The parameters of each embodiment specifically meeting the above conditions are shown in Table 1 below:

[0077]

[0078] Table 1

[0079] The first embodiment

[0080] See Figure 1 and Figure 2 In this embodiment, the aperture stop STO is located on the object side of the fourth lens L4. The third lens L3 and the tenth lens L10 are plastic aspherical lenses, and the fourth lens L4 is a glass spherical lens. Focal length: 4.7 - 9.6 mm; F number: 1.0 - 1.5; TTL_W: 54.73 mm.

[0081] The relevant parameters of each lens in this embodiment, including surface type, radius of curvature, thickness, refractive index, are shown in Table 2 below:

[0082] Surface Serial Number Surface Type Radius of Curvature Thickness Refractive Index Abbe Number 1 Spherical Surface 750.00 0.70 1.71 53.8 2 Spherical Surface 9.88 5.04 3 Aspherical Surface 34.57 1.61 1.54 55.7 4 Aspherical Surface 8.31 0.68 5 Aspherical Surface 22.76 2.51 1.66 19.5 6 Aspherical Surface 758.92 D1 7(STO) Spherical Surface Infinity 0.30 8 Spherical Surface 92.00 1.26 1.94 18.0 9 Spherical Surface 232.47 D2 10 Aspherical Surface 15.23 6.08 1.82 40.0 11 Aspherical Surface -27.46 1.07 12 Spherical Surface 138.87 0.60 1.67 26.1 13 Spherical Surface 7.51 5.51 1.46 90.2 14 Spherical Surface -41.19 0.10 15 Aspherical Surface 21.72 2.13 1.64 21.5 16 Aspherical Surface 12.70 0.69 17 Aspherical Surface -30.59 1.85 1.54 56.0 18 Aspherical Surface -9.85 0.10 19 Aspherical Surface 7.06 1.91 1.64 23.5 20 Aspherical Surface 6.52 D3 21 Aspherical Surface 47.62 1.41 1.53 30.0 22 Aspherical Surface -300.00 2.90 23 Spherical Surface Infinity 0.70 1.52 64.2 24 Spherical Surface Infinity 0.57 IMA Spherical Surface Infinity

[0083] Table 2

[0084] The K value and aspherical coefficient in this embodiment are shown in Table 3 below:

[0085]

[0086]

[0087] Table 3

[0088] When changing from the wide-angle end to the telephoto end, the variable interval values are shown in Table 4 below:

[0089] Surface Serial Number Thickness Wide Angle End Telephoto End 6 D1 10.16 2.18 9 D2 5.62 0.10 20 D3 1.23 6.75

[0090] Table 4

[0091] Combined with Figure 3 and Figure 4 In this embodiment, the zoom lens can ensure a super large aperture throughout the entire zoom range from the wide-angle end to the telephoto end with a short stroke. While ensuring the performance of the system, the production cost is greatly reduced. And it can still ensure good resolution at high temperature of 80°C and low temperature of -40°C, without defocusing at high and low temperatures.

[0092] The second embodiment

[0093] See Figure 5 and Figure 6, in this embodiment, the aperture STO is located on the object side of the fourth lens L4. The third lens L3 and the fourth lens L4 are plastic aspherical lenses, and the tenth lens L10 is a glass spherical lens. Focal length: 4.8 - 9.05 mm; F number: 1.0 - 1.4; TTL_W: 50.50 mm.

[0094] The relevant parameters of each lens in this embodiment, including surface type, radius of curvature, thickness, refractive index, are shown in Table 5 below:

[0095] Surface Serial Number Surface Type Radius of Curvature Thickness Refractive Index Abbe Number 1 Spherical Surface 171.21 0.75 1.80 46.6 2 Spherical Surface 9.37 4.31 3 Aspherical Surface 36.63 1.61 1.54 55.7 4 Aspherical Surface 7.75 0.42 5 Aspherical Surface 18.22 2.39 1.66 20.4 6 Aspherical Surface 918.09 D1 7(STO) Spherical Surface Infinity 0.30 8 Aspherical Surface 41.77 1.56 1.64 23.5 9 Aspherical Surface 94.58 D2 10 Aspherical Surface 12.07 5.58 1.60 70.0 11 Aspherical Surface -23.76 1.13 12 Spherical Surface 49.72 0.60 1.64 43.7 13 Spherical Surface 7.05 4.45 1.61 68.4 14 Spherical Surface 23.69 0.10 15 Aspherical Surface 9.57 1.98 1.65 23.5 16 Aspherical Surface 6.57 1.07 17 Aspherical Surface 23.47 1.73 1.54 56.0 18 Aspherical Surface -38.20 0.10 19 Spherical Surface 9.80 3.10 1.74 56.3 20 Spherical Surface 17.47 D3 21 Aspherical Surface 47.72 1.43 1.54 55.7 22 Aspherical Surface 55.43 2.82 23 Spherical Surface Infinity 0.70 1.52 64.2 24 Spherical Surface Infinity 0.48 IMA Spherical Surface Infinity

[0096] Table 5

[0097] The K value and aspherical coefficient in this embodiment are shown in Table 6 below:

[0098]

[0099] Table 6

[0100] When changing from the wide-angle end to the telephoto end, the variable interval values are shown in Table 7 below:

[0101] Surface Serial Number Thickness Wide Angle End Telephoto End 6 D1 7.92 1.65 9 D2 5.01 0.10 20 D3 0.96 5.87

[0102] Table 7

[0103] Combined Figure 7 and Figure 8 , the zoom lens of this embodiment can ensure a super large aperture throughout the entire zoom range from the wide-angle end to the telephoto end with a short stroke. While ensuring the performance of the system, the production cost is greatly reduced. And it can still ensure good resolution at high temperature of 80 °C and low temperature of -40 °C, without defocusing at high and low temperatures.

[0104] The third embodiment

[0105] Refer to Figure 9 and Figure 10 , in this embodiment, the aperture STO is located on the object side of the fourth lens L4. The fourth lens L4 and the tenth lens L10 are plastic aspherical lenses, and the third lens L3 is a glass spherical lens. Focal length: 4.6 - 9.35 mm; F number: 1.0 - 1.48; TTL_W: 52.87 mm.

[0106] The relevant parameters of each lens in this embodiment, including surface type, radius of curvature, thickness, refractive index, are shown in Table 8 below:

[0107]

[0108]

[0109] Table 8

[0110] The K value and the aspherical coefficients in this embodiment are shown in Table 9 below:

[0111]

[0112] Table 9

[0113] When changing from the wide-angle end to the telephoto end, the variable interval values are shown in Table 10 below:

[0114] Surface Serial Number Thickness Wide Angle End Telephoto End 6 D1 10.33 1.63 9 D2 5.35 0.10 20 D3 1.23 6.48

[0115] Table 10

[0116] Combined Figure 11 and Figure 12 , the zoom lens of this embodiment can ensure a super large aperture throughout the entire zoom range from the wide-angle end to the telephoto end with a short stroke. While ensuring the various performances of the system, the production cost is greatly reduced. And it can still ensure good resolution at high temperature of 80 °C and low temperature of -40 °C, without defocusing at high and low temperatures.

[0117] The fourth embodiment

[0118] Referring to Figure 13 and Figure 14 , in this embodiment, the aperture stop STO is located on the image side of the fourth lens L4, the third lens L3 and the tenth lens L10 are plastic aspherical lenses, and the fourth lens L4 is a glass spherical lens. Focal length: 4.7 - 9.4 mm; F number: 1.0 - 1.4; TTL_W: 54.69 mm.

[0119] The relevant parameters of each lens in this embodiment, including the surface type, radius of curvature, thickness, and refractive index, are shown in Table 11 below:

[0120]

[0121]

[0122] Table 11

[0123] The K value and the aspherical coefficients in this embodiment are shown in Table 12 below:

[0124]

[0125]

[0126] Table 12

[0127] When changing from the wide-angle end to the telephoto end, the variable interval values are shown in Table 13 below:

[0128] Surface Serial Number Thickness Wide Angle End Telephoto End 6 D1 9.21 1.04 9 D2 5.62 0.10 20 D3 1.17 6.69

[0129] Table 13

[0130] Combined Figure 15 and Figure 16 With this, the zoom lens of this embodiment can ensure a super large aperture throughout the entire zoom range from the wide-angle end to the telephoto end with a short stroke. While ensuring the various performances of the system, the production cost is greatly reduced. Moreover, good resolution can still be ensured at a high temperature of 80 °C and a low temperature of -40 °C, and there is no defocusing at high and low temperatures.

[0131] The above is only one embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A zoom lens, comprising a compensation group (G1) with a negative optical power, a first fixed group (G2) with a positive optical power, and a variable power group (G3) with a positive optical power, which are arranged in sequence from the object side to the image side along the optical axis, characterized in that, It further includes a second fixed group (G4) located on the image side of the variable magnification group (G3), with a total of four lens groups. The optical power of the second fixed group (G4) is positive. During the variable magnification process, the first fixed group (G2) and the second fixed group (G4) are fixed relative to the image plane position, and the compensating group (G1) and the variable magnification group (G3) can move along the optical axis; The compensating group (G1) includes a first lens (L1) with a negative optical power, a second lens (L2) with a negative optical power, and a third lens (L3) with a positive optical power, arranged in sequence from the object side to the image side, with a total of three lenses; The first fixed group (G2) includes a fourth lens (L4) with a positive optical power, with a total of one lens; The variable magnification group (G3) includes a fifth lens (L5) with a positive optical power, a sixth lens (L6) with a negative optical power, a seventh lens (L7) with a positive optical power, an eighth lens (L8) with a negative optical power, a ninth lens (L9) with a positive optical power, and a tenth lens (L10) with a positive optical power, arranged in sequence from the object side to the image side, with a total of six lenses; The second fixed group (G4) includes an eleventh lens (L11) with a positive optical power, with a total of one lens; The sixth lens (L6) and the seventh lens (L7) are cemented to form a cemented lens group; the focal length FB of the cemented lens group in the variable magnification group (G3) and the focal length FⅢ of the variable magnification group (G3) satisfy the following relationship: 2.50 < |FB / FⅢ| < 18.

00.

2. The zoom lens according to claim 1, characterized in that ,The first lens (L1) is a convex-concave or concave-concave lens, the second lens (L2) is a convex-concave lens in the paraxial region, and the third lens (L3) is a convex-concave lens in the paraxial region.

3. The zoom lens according to claim 1, wherein The fourth lens (L4) is a convex-concave lens in the paraxial region.

4. The zoom lens according to claim 3, characterized in that, The fifth lens (L5) is a convex-convex lens, the sixth lens (L6) is a convex-concave lens, the seventh lens (L7) is a convex-concave or convex-convex lens, the eighth lens (L8) is a convex-concave lens in the paraxial region, the ninth lens (L9) is a convex-convex or convex-concave lens in the paraxial region, and the tenth lens (L10) is a convex-concave lens in the paraxial region.

5. The zoom lens according to claim 4, wherein The eleventh lens (L11) is a convex-convex or convex-concave lens in the paraxial region.

6. The zoom lens according to claim 1, characterized in that, The zoom lens further includes a fixed-position aperture (STO), and the aperture (STO) is located between the compensating group (G1) and the first fixed group (G2) or between the first fixed group (G2) and the variable magnification group (G3).

7. The zoom lens according to claim 6, wherein, The diameter SD_STO of the aperture (STO) and the distance TTL_W from the front surface vertex of the first lens (L1) to the image plane at the wide-angle end of the zoom lens satisfy the following relationship: 0.08 < SD_STO / TTL_W < 0.

20.

8. The zoom lens according to claim 1 or 3, characterized in that, The focal length F4 of the fourth lens (L4) and the focal length Fw of the zoom lens at the wide-angle end satisfy the following relationship: 10.00 < |F4 / Fw| < 35.

00.

9. The zoom lens according to claim 1 or 5, characterized in that, The focal length F11 of the eleventh lens (L11) and the focal length Fw of the zoom lens at the wide-angle end satisfy the following relationship: 12.00 < |F11 / Fw|.

10. The zoom lens according to any one of claims 1-6, characterized in that, The focal length FⅠ of the compensating group (G1) and the focal length FⅢ of the zooming group (G3) satisfy the following relationship: 0.70 ≤ |FⅠ / FⅢ| ≤ 0.

90.

11. The zoom lens according to claim 1 or 2, characterized in that, The distance ΔD that the compensating group (G1) moves from the wide-angle end to the telephoto end of the zoom lens and the distance TTL_W from the front surface vertex of the first lens (L1) to the image plane at the wide-angle end of the zoom lens satisfy the following relationship: 0.11 < ΔD / TTL_W < 0.

18.

12. The zoom lens according to claim 1 or 4, characterized in that, The focal length F5 of the fifth lens (L5) and the focal length FⅢ of the zooming group (G3) satisfy the following relationship: 0.95 < F5 / FⅢ < 1.

30.

13. The zoom lens according to claim 1 or 4, characterized in that, The Abbe number vd6 of the sixth lens (L6) and the Abbe number vd7 of the seventh lens (L7) satisfy the following relationship: 22 < |vd7 - vd6| < 66.

14. The zoom lens according to claim 1 or 4, characterized in that, The fifth lens (L5) is an aspherical glass lens, and its refractive index nd5 and Abbe number vd5 respectively satisfy the following conditions: 1.55 < nd5 < 1.85; 40 ≤ vd5 ≤ 70.

15. The zoom lens according to any one of claims 1-6, characterized in that, The second lens (L2), the eighth lens (L8), the ninth lens (L9), and the eleventh lens (L11) are plastic aspherical lenses, and the third lens (L3), the fourth lens (L4), and the tenth lens (L10) are spherical or aspherical lenses.

16. The zoom lens according to claim 1 or 4, characterized in that, The focal length F8 of the eighth lens (L8), the focal length F9 of the ninth lens (L9), the focal length F10 of the tenth lens (L10), and the focal length FⅢ of the zooming group (G3) respectively satisfy the following relationships: 2.00 < |F8 / FⅢ| < 5.00; 1.00 < F9 / FⅢ < 3.00; 1.50 < F10 / FⅢ.

Images