Zoom lens

Abstract

The present invention relates to a zoom lens, which sequentially includes, in the direction from the object side to the image side along the optical axis: a first lens group (G1) with positive optical power, a second lens group (G2) with negative optical power, a stop, a third lens group (G3) with positive optical power, and a fourth lens group (G4) with positive optical power. The second lens group (G2) and the fourth lens group (G4) move along the optical axis. The distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) when the zoom lens is at the telephoto end 12t and the distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) when the zoom lens is at the wide-angle end 12w satisfy the relational expression with the focal length fw of the zoom lens at the wide-angle end: 0.7 ≤ (d 12t - d 12w ) / fw ≤ 1.2. This zoom lens achieves high imaging performance with a wide field of view, small volume, low cost, and a resolution of over 4K.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging optical systems, and in particular to a zoom lens. Background Art

[0002] The development of AI face recognition technology has put forward higher requirements on the aperture, image plane, resolution, infrared performance and high and low temperature performance of camera lenses.

[0003] Existing lenses generally have the following shortcomings: small aperture, which cannot meet the brightness requirements of images in low-light environments; large image surface and small size cannot be taken into account at the same time, which cannot meet the space requirements of the lens; low resolution, the mainstream 1080P lens has a resolution of 2 million, which can no longer meet the high-pixel requirements of face recognition; infrared performance and high and low temperature performance cannot be taken into account at the same time, and the requirements of day and night confocality are often met by sacrificing high and low temperature performance, but this can no longer meet the real-time requirements of face recognition in high and low temperature environments.

[0004] A zoom lens disclosed in Chinese patent CN102087404B mainly solves the problem of increasing the amount of light entering and the zoom ratio while meeting the requirements of compact size, and cannot take into account the above-mentioned multiple performances. Summary of the invention

[0005] In order to overcome the defects in the above-mentioned prior art, the object of the present invention is to provide a zoom lens to achieve a wide field of view, a small size, a low cost, and a high imaging performance with a resolution of more than 4k.

[0006] To achieve the above-mentioned object, the present invention provides a zoom lens, which comprises, in order from the object side to the image side of the optical axis: a first lens group with positive focal power, a second lens group with negative focal power, an aperture, a third lens group with positive focal power, and a fourth lens group with positive focal power, wherein the second lens group and the fourth lens group move along the optical axis, and the distance d from the last surface of the first lens group to the first surface of the second lens group when the zoom lens is at the telephoto end is 12t , the distance d from the last surface of the first lens group to the first surface of the second lens group when the zoom lens is at the wide-angle end 12w The relationship between the focal length fw of the zoom lens at the wide-angle end is: 0.7≤(d 12t -d 12w ) / fw≤1.2.

[0007] According to one aspect of the present invention, the first lens group comprises at least two lenses with positive power and one lens with negative power;

[0008] The image side surface of the lens closest to the image plane in the first lens group is a concave surface;

[0009] The lens of the first lens group closest to the object plane has negative optical power, and the object-side surface of the lens of the first lens group closest to the object plane is convex, and the image-side surface is concave.

[0010] According to one aspect of the present invention, a distance TTL from the first surface of the first lens group to the image plane and a diameter φ of the imaging target surface of the zoom lens satisfy the relationship: 4≤TTL / φ≤7.5.

[0011] According to one aspect of the present invention, the second lens group comprises at least one lens with positive power, two lenses with negative power and two plastic lenses;

[0012] The object side surface of the lens of the second lens group closest to the image plane is convex.

[0013] According to one aspect of the present invention, the lens closest to the image plane in the second lens group is a plastic lens.

[0014] According to one aspect of the present invention, the second lens group includes at least one plastic lens whose Abbe number satisfies the following relationship: VD 21 ≥50;

[0015] The second lens group further includes at least one plastic lens whose Abbe number satisfies the following relationship: VD 22 ≤30.

[0016] According to one aspect of the present invention, the third lens group includes at least five lenses;

[0017] The third lens group at least includes two lenses with negative power, two lenses with positive power, two plastic lenses and one cemented lens;

[0018] The lens of the third lens group closest to the image plane has negative optical power, and the image side surface of the lens of the third lens group closest to the image plane is a concave surface.

[0019] According to one aspect of the present invention, the focal length f3 of the third lens group and the focal length fw of the zoom lens at the wide-angle end satisfy the relationship: 0.8≤f3 / fw≤2.

[0020] According to one aspect of the present invention, the third lens group includes one or at least one low-dispersion glass lens, and the Abbe number VD and the refractive index ND of the lens respectively satisfy the following relationship:

[0021] 65≤VD≤100;

[0022] 1.4≤ND≤1.60.

[0023] According to one aspect of the present invention, the fourth lens group comprises at least two lenses with positive power, one lens with negative power and two plastic lenses;

[0024] The lens of the fourth lens group closest to the object plane has positive refractive power;

[0025] The lens of the fourth lens group closest to the image plane is a plastic lens.

[0026] According to one aspect of the present invention, when the zoom lens is at the telephoto end, the distance d from the last surface of the first lens group to the first surface of the second lens group is 12t , the distance d from the last surface of the first lens group to the first surface of the second lens group when the zoom lens is at the wide-angle end 12w The distance TTL from the first surface of the first lens group to the image plane satisfies the relationship: 3≤TTL / (d 12t -d 12w )≤6.

[0027] According to one aspect of the present invention, when the zoom lens is at the telephoto end, the distance d from the last surface of the first lens group to the first surface of the second lens group is 12t , the distance d from the last surface of the first lens group to the first surface of the second lens group when the zoom lens is at the wide-angle end 12w , the focal length fw of the zoom lens at the wide-angle end and the focal length ft of the zoom lens at the telephoto end satisfy the relationship: 3≤(d 12t -d 12w ) / (ft / fw)≤6.5.

[0028] According to the solution of the present invention, the zoom lens adopts a variable diaphragm and an optical structure of a four-group architecture with a specific optical power combination, so that the aperture of the zoom lens can reach F1.4, which can ensure the brightness of the image in a low-light environment, and take into account the imaging performance of wide field of view, small size, low cost and resolution of more than 4k. And adopt a glass-plastic hybrid lens structure, reasonably distribute abnormal dispersion glass lenses and high refractive index glass lenses, to achieve high-quality imaging effects, with excellent resolution, while ensuring a large magnification to achieve a small size and reduce design costs. And maximize the imaging performance in the smallest possible volume.

[0029] The zoom lens also achieves the correction of chromatic aberration and secondary spectrum in the 420-940nm band, and can ensure resolution without refocusing when switching between day and night. While taking into account infrared performance, it solves the problem of focus drift in high and low temperature environments, making the zoom lens not out of focus in the temperature range of -40℃ to 80℃, suitable for various high and low temperature environments, greatly broadening the application range of the zoom lens.

[0030] The zoom lens of the present invention has low distortion in the whole zooming process, ensuring that the deformation of the shooting picture is small, and can also achieve a wide range of focusing distances. The zooming process can ensure that the object distance from 0.1m to infinity can be clearly focused, and the imaging effect is good. In addition, the single component and assembly tolerance of the zoom lens are good, and it has good manufacturability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram showing the lens structure of the zoom lens of Embodiment 1 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0032] Figure 2 A schematic diagram showing the lens structure of the zoom lens of Embodiment 1 of the present invention at the telephoto end (T) when the object distance is infinite;

[0033] Figure 3 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 1 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0034] Figure 4 A schematic diagram showing the positional chromatic aberration of the zoom lens of Example 1 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0035] Figure 5 Schematically showing the distortion diagram of the zoom lens of Example 1 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0036] Figure 6 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 1 of the present invention at the telephoto end (T) when the object distance is infinite;

[0037] Figure 7 A schematic diagram showing the position chromatic aberration of the zoom lens of Example 1 of the present invention at the telephoto end (T) when the object distance is infinite;

[0038] Figure 8 Schematically showing the distortion diagram of the zoom lens at the telephoto end (T) when the object distance is infinite according to Example 1 of the present invention;

[0039] Fig. 9 A schematic diagram showing the lens structure of the zoom lens of Embodiment 2 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0040] Fig.10 A schematic diagram showing the lens structure of the zoom lens of Embodiment 2 of the present invention at the telephoto end (T) when the object distance is infinite;

[0041] Fig.11 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 2 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0042] Fig.12 A schematic diagram showing the positional chromatic aberration of the zoom lens of Example 2 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0043] Fig.13 Schematically showing the distortion diagram of the zoom lens of Example 2 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0044] Fig.14 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 2 of the present invention at the telephoto end (T) when the object distance is infinite;

[0045] Fig.15 A schematic diagram showing the position chromatic aberration of the zoom lens of Example 2 of the present invention at the telephoto end (T) when the object distance is infinite;

[0046] Fig.16 Schematically showing the distortion diagram of the zoom lens at the telephoto end (T) when the object distance is infinite according to Example 2 of the present invention;

[0047] Fig.17 A schematic diagram showing the lens structure of the zoom lens of Embodiment 3 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0048] Fig.18 A schematic diagram showing the lens structure of the zoom lens of Embodiment 3 of the present invention at the telephoto end (T) when the object distance is infinite;

[0049] Fig.19 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 3 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0050] Fig. 20 A schematic diagram showing the positional chromatic aberration of the zoom lens of Example 3 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0051] Fig.21 Schematically showing the distortion diagram of the zoom lens of Example 3 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0052] Fig. 22 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 3 of the present invention at the telephoto end (T) when the object distance is infinite;

[0053] Fig.23 A schematic diagram showing the position chromatic aberration of the zoom lens of Example 3 of the present invention at the telephoto end (T) when the object distance is infinite;

[0054] Fig.24 Schematically showing the distortion diagram of the zoom lens of Example 3 of the present invention at the telephoto end (T) when the object distance is infinite;

[0055] Fig.25 A schematic diagram showing the lens structure of the zoom lens of Embodiment 4 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0056] Fig.26 A schematic diagram showing the lens structure of the zoom lens of Embodiment 4 of the present invention at the telephoto end (T) when the object distance is infinite;

[0057] Fig. 27 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 4 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0058] Fig.28 A schematic diagram showing the positional chromatic aberration of the zoom lens of Example 4 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0059] Fig.29 Schematically showing the distortion diagram of the zoom lens of Example 4 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0060] Fig.30 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 4 of the present invention at the telephoto end (T) when the object distance is infinite;

[0061] Fig.31 A schematic diagram showing the position chromatic aberration of the zoom lens of Example 4 of the present invention at the telephoto end (T) when the object distance is infinite;

[0062] Fig.32 Schematically showing the distortion diagram of the zoom lens of Example 4 of the present invention at the telephoto end (T) when the object distance is infinite;

[0063] Fig.33 A schematic diagram showing the lens structure of the zoom lens of Embodiment 5 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0064] Fig.34 A schematic diagram showing the lens structure of the zoom lens of Embodiment 5 of the present invention at the telephoto end (T) when the object distance is infinite;

[0065] Fig.35 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 5 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0066] Fig.36 A schematic diagram showing the positional chromatic aberration of the zoom lens of Example 5 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0067] Fig.37 Schematically showing the distortion diagram of the zoom lens of Example 5 of the present invention at the wide-angle end (W) when the object distance is infinite;

[0068] Fig.38 A diagram schematically showing the magnification chromatic aberration of the zoom lens of Example 5 of the present invention at the telephoto end (T) when the object distance is infinite;

[0069] Fig.39 A schematic diagram showing the position chromatic aberration of the zoom lens of Example 5 of the present invention at the telephoto end (T) when the object distance is infinite;

[0070] Fig.40 The distortion diagram of the zoom lens of Example 5 of the present invention at the telephoto end (T) when the object distance is infinite is schematically shown. DETAILED DESCRIPTION

[0071] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0072] When describing the embodiments of the present invention, the orientation or positional relationship expressed by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the relevant drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0073] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not therefore limited to the following embodiments.

[0074] like Figure 1 or Figure 2 As shown, the zoom lens of the present invention includes, in order from the object side to the image side of the optical axis: a first lens group G1 with positive focal power, a second lens group G2 with negative focal power, an aperture stop, a third lens group G3 with positive focal power, and a fourth lens group G4 with positive focal power. The second lens group G2 and the fourth lens group G4 move along the optical axis, and the third lens group G3 includes at least five lenses. Figure 1 and Figure 2As shown, by moving the second lens group G2 from the object side to the image side along the optical axis, the zoom is changed from the wide-angle end to the telephoto end. At the same time, by moving the fourth lens group G4 along the optical axis, the change in the image plane position during the zoom process can be corrected. The zoom lens adopts a variable iris stop and the design of the above optical mechanism, and the aperture can reach F1.4. The zoom lens can ensure the brightness of the image in a low-light environment, taking into account the imaging performance of wide field of view, small size, low cost and resolution of more than 4k.

[0075] For the first lens group G1, the group includes at least two lenses with positive power and one lens with negative power. The image side surface of the lens closest to the image plane of the first lens group G1 is concave. The lens closest to the object plane of the first lens group G1 has negative power, and the object side surface of the lens closest to the object plane of the first lens group G1 is convex, and the image side surface is concave.

[0076] The distance TTL from the first surface of the first lens group G1 to the image plane and the diameter φ of the imaging target surface of the zoom lens satisfy the relationship: 4≤TTL / φ≤7.5. When the value of the above relationship is less than 4, the aberration balance at the telephoto end of the zoom lens is limited, and it is difficult to improve the resolution. When the value of the above relationship is greater than 7.5, the size of the zoom lens increases, the zoom efficiency decreases, and the cost increases. When the above relationship is satisfied, the zoom lens has high performance with small size, high resolution, low cost and zoom efficiency.

[0077] The second lens group G2 includes at least one lens with positive power, two lenses with negative power, and two plastic lenses. The object side of the lens closest to the image plane of the second lens group G2 is convex. The lens closest to the image plane of the second lens group G2 is a plastic lens. The second lens group G2 includes at least one plastic lens whose Abbe number satisfies the following relationship: VD 21 ≥50; the second lens group G2 also includes at least one plastic lens whose Abbe number satisfies the following relationship: VD 22 ≤30. When the above two relationships are met, the field curvature and astigmatism caused by the large incident angle light at the wide-angle end can be effectively reduced, the resolution at the wide-angle end can be comprehensively improved, and it plays a key role in solving the focus drift problem of the system under high and low temperature conditions.

[0078] For the third lens group G3, the group includes at least two lenses with negative power, two lenses with positive power, two plastic lenses and one cemented lens; the lens closest to the image plane of the third lens group G3 has negative power, and the image side surface of the lens closest to the image plane of the third lens group G3 is concave. Among them, the focal length f3 of the third lens group G3 and the focal length fw of the zoom lens at the wide-angle end satisfy the relationship: 0.8≤f3 / fw≤2. When the value of the above relationship is less than 0.8, the tolerance sensitivity of the third lens group G3 deteriorates, and the resolution consistency of the zoom lens deteriorates. When the value of the above relationship is greater than 2, the volume and length of the zoom lens increase, which is not conducive to meeting the performance of small volume. When the above relationship is satisfied, the zoom lens has high performance with small volume, high resolution and low cost.

[0079] The third lens group G3 includes one or at least one low-dispersion glass lens, and the Abbe number VD and the refractive index ND of the lens satisfy the following relationship:

[0080] 65≤VD≤100;

[0081] 1.4≤ND≤1.60.

[0082] The introduction of low-dispersion glass lenses can reasonably balance the chromatic aberration produced by the first lens group G1 and the second lens group G2, and comprehensively improve the resolution of the zoom lens throughout the zoom range.

[0083] The fourth lens group G4 includes at least two lenses with positive power, one lens with negative power and two plastic lenses. The lens closest to the object plane of the fourth lens group G4 has positive power. The lens closest to the image plane of the fourth lens group G4 is a plastic lens.

[0084] The distance d from the last surface of the first lens group G1 to the first surface of the second lens group G2 when the zoom lens is at the telephoto end 12t , the distance d from the last surface of the first lens group G1 to the first surface of the second lens group G2 when the zoom lens is at the wide-angle end 12w The relationship between the focal length fw of the zoom lens at the wide-angle end is: 0.7≤(d 12t -d 12w ) / fw≤1.2. When the value of the above relational expression is less than 0.7, the aberration between the first lens group G1 and the second lens group G2 increases, causing the resolution of the zoom lens to decrease. When the value of the above relational expression is greater than 1.2, the volume of the zoom lens increases, causing the design cost to increase.

[0085] The distance d from the last surface of the first lens group G1 to the first surface of the second lens group G2 when the zoom lens is at the telephoto end 12t, the distance d from the last surface of the first lens group G1 to the first surface of the second lens group G2 when the zoom lens is at the wide-angle end 12w The distance TTL from the first surface of the first lens group G1 of the zoom lens to the image plane satisfies the relationship: 3≤TTL / (d 12t -d 12w )≤6. When the value of the above relation is less than 3, the size of the zoom lens increases, the design cost increases, and the zoom efficiency decreases. When the value of the above relation is greater than 6, the aberration between the first lens group G1 and the second lens group G2 increases, causing the resolution of the zoom lens to decrease and the group tolerance sensitivity to deteriorate.

[0086] The distance d from the last surface of the first lens group G1 to the first surface of the second lens group G2 when the zoom lens is at the telephoto end 12t , the distance d from the last surface of the first lens group G1 to the first surface of the second lens group G2 when the zoom lens is at the wide-angle end 12w , the focal length fw of the zoom lens at the wide angle end and the focal length ft of the zoom lens at the telephoto end satisfy the relationship: 3≤(d 12t -d 12w ) / (ft / fw)≤6.5. When the value of the above relationship is less than 3, the resolution of the zoom lens at both the telephoto end and the wide-angle end decreases, and the tolerance sensitivity becomes worse. When the value of the above relationship is greater than 6.5, the size of the zoom lens increases, the design cost increases, and the zoom efficiency decreases.

[0087] The zoom lens of the present invention is specifically described below with five embodiments. In the following embodiments, the aperture stop is denoted as one side stop, the image plane IMA is denoted as one side Image, and the cemented surface of the cemented lens is denoted as one side.

[0088] Parameters of various embodiments that specifically meet the above relationship are shown in Table 1 below:

[0089] Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[0.7≤(d 12t -d 12w ) / fw≤1.2]]> 0.74 1.17 0.99 0.81 0.83 <![CDATA[3≤TTL / (d 12t -d 12w )≤6]]> 5.03 4.32 3.91 6.00 4.43 <![CDATA[3≤(d 12t -d 12w ) / (ft / fw)≤6.5]]> 6.01 6.01 5.63 3.53 5.79 4≤TTL / φ≤7.5 5.51 6.13 5.48 6.90 7.03 0.8≤f3 / fw≤2 0.92 1.18 1.06 1.13 1.76

[0090] Table 1

[0091] Example 1

[0092] See also Figure 1 and Figure 2 In this embodiment, the parameters of the zoom lens are as follows:

[0093] TTL = 48.53 mm;

[0094] FNO(WIDE)=1.60;

[0095] Wide-angle focal length fw = 13.1 mm;

[0096] The focal length at the telephoto end is ft=21.0mm.

[0097] The relevant parameters of each lens of the zoom lens of this embodiment include surface type, curvature radius R value, thickness d, refractive index ND and Abbe number VD of the material. Surf1 to surf27 represent each surface of each lens, cemented lens and aperture stop in the zoom lens, as shown in Table 2 below.

[0098]

[0099]

[0100] Table 2 In this embodiment, the aspherical lens of the zoom lens satisfies the following formula:

[0101]

[0102] Where Z represents the axial distance from the surface to the vertex at a height h perpendicular to the optical axis along the optical axis; c represents the curvature at the vertex of the aspheric surface; k represents the cone coefficient; A4, A6, A8, A 10 , A 12 They represent the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order aspheric coefficients respectively. The values ​​of the aspheric surface are shown in Table 3 below.

[0103] k <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> surf8 0 -2.35E-03 3.28E-05 1.87E-07 -9.95E-09 5.21E-11 surf9 -2.0380503 -1.45E-03 2.54E-05 -1.50E-07 6.29E-09 -1.74E-10 surf10 2.2702834 -3.10E-05 -1.18E-07 -6.08E-07 2.43E-08 -3.55E-10 surf11 18.859643 -2.09E-04 7.25E-06 -2.33E-07 6.88E-09 -1.44E-10 surf15 16.087896 -3.67E-04 5.22E-06 3.50E-07 -6.19E-09 -6.31E-11 surf16 -0.60217865 2.18E-04 1.78E-06 3.80E-08 -4.27E-10 -4.45E-11 surf17 -1.4176661 -5.39E-04 2.16E-05 -1.75E-07 -5.23E-08 5.66E-10 surf18 -3.9627671 -6.67E-04 1.75E-05 4.26E-07 -1.28E-07 2.61E-09 surf24 0 2.87E-03 -7.93E-05 -9.99E-07 -9.92E-08 -5.71E-09 surf25 0 1.36E-03 2.00E-04 -4.95E-06 -6.44E-09 -3.08E-08 surf26 0 -3.64E-03 1.39E-04 2.63E-06 -6.90E-09 -5.50E-09 surf27 0 -1.80E-03 -2.49E-05 7.50E-06 -2.90E-07 7.66E-09

[0104] Table 3

[0105] The zoom data of the zoom lens of this embodiment is shown in Table 4 below.

[0106] Surface serial number Wide angle Telephoto end D5 0.72 10.36 D11 14.99 5.36 D21 2.44 1.62 D27 3.68 4.49

[0107] Table 4

[0108] In the second lens group G2 of the zoom lens of this embodiment, the fifth lens L5 is a plastic lens with an Abbe number of VD L5 =56.00. The sixth lens L6 is a plastic lens, and its Abbe number is VD L6 =23.50. The third lens group G3 includes two low-dispersion glass lenses, namely the seventh lens L7 and the tenth lens L10. The refractive index and Abbe number of the seventh lens L7 are: ND L7 =1.50, VD L7 =81.60; the refractive index and Abbe number of the tenth lens L10 are: ND L10 =1.44, VD L10 =95.10.

[0109] Therefore, combined with Figures 1 to 8, and the related design parameters and data in Tables 1 to 4 above, by using a variable iris and a four-group optical structure with a specific focal power combination, the aperture of the zoom lens can reach F1.4, which can ensure the brightness of the image in a low-light environment, taking into account the imaging performance of wide field of view, small size, low cost and resolution of more than 4k. And adopting a glass-plastic hybrid lens structure, a reasonable distribution of abnormal dispersion glass lenses and high refractive index glass lenses, to achieve high-quality imaging effects, with excellent resolution, while ensuring a large magnification to achieve a small size and reduce design costs. And maximize the imaging performance in the smallest possible volume.

[0110] The zoom lens also achieves the correction of chromatic aberration and secondary spectrum in the 420-940nm band, and can ensure resolution without refocusing when switching between day and night. While taking into account infrared performance, it solves the problem of focus drift in high and low temperature environments, making the zoom lens not out of focus in the temperature range of -40℃ to 80℃, suitable for various high and low temperature environments, greatly broadening the application range of the zoom lens.

[0111] The zoom lens has low distortion throughout the zoom range, ensuring that the image is less deformed and that a wide range of object distances can be achieved. The zoom lens can ensure that the object distance from 0.1m to infinity can be clearly focused throughout the zoom range, with good imaging effects. In addition, the zoom lens has good tolerances for individual components and assembly, and has good manufacturability.

[0112] Example 2

[0113] See also Fig. 9 and Fig.10 In this embodiment, the parameters of the zoom lens are as follows:

[0114] TTL = 54.03 mm;

[0115] FNO(WIDE)=1.65;

[0116] Wide-angle focal length fw = 10.7 mm;

[0117] The focal length at the telephoto end is ft=22.3mm.

[0118] The relevant parameters of each lens of the zoom lens of this embodiment include surface type, curvature radius R value, thickness d, refractive index ND and Abbe number VD of the material. Surf 1 to surf 27 represent each surface of each lens, cemented lens and aperture stop in the zoom lens, as shown in Table 5 below.

[0119]

[0120]

[0121] Table 5 In this embodiment, the aspherical lens of the zoom lens satisfies the following formula:

[0122]

[0123] Where Z represents the axial distance from the surface to the vertex at a height h perpendicular to the optical axis along the optical axis; c represents the curvature at the vertex of the aspheric surface; k represents the cone coefficient; A4, A6, A8, A 10 , A 12 They represent the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order aspheric coefficients respectively. The values ​​of the aspheric surface are shown in Table 6 below.

[0124] k <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> surf8 0 -2.36E-03 3.90E-05 2.10E-07 -1.74E-08 1.78E-10 surf9 -2.0380503 -1.41E-03 2.65E-05 -7.63E-08 6.77E-09 -2.28E-10 surf10 2.2702834 -2.60E-05 -9.92E-08 -6.94E-07 2.92E-08 -4.64E-10 surf11 18.859643 -1.93E-04 9.23E-06 -2.71E-07 2.27E-09 -6.86E-11 surf13 -0.60 -8.40E-05 -6.52E-06 -3.02E-07 7.77E-10 1.02E-10 surf14 0.00 -4.04E-06 -3.51E-07 -2.10E-09 2.10E-10 0.00E+00 surf17 -1.4176661 -5.61E-04 2.28E-05 -3.17E-07 -5.12E-08 7.59E-10 surf18 -3.9627671 -5.46E-04 9.36E-06 4.05E-07 -1.38E-07 3.00E-09 surf24 0 3.92E-03 6.02E-05 -2.19E-05 3.29E-07 8.91E-09 surf25 0 9.92E-04 5.56E-04 -1.14E-05 -1.87E-06 6.12E-08 surf26 0 -6.75E-03 4.61E-04 3.15E-06 -3.43E-07 -7.35E-09 surf27 0 -3.49E-03 2.42E-05 2.26E-05 -1.82E-06 5.78E-08

[0125] Table 6

[0126] The zoom data of the zoom lens of this embodiment is shown in Table 7 below.

[0127] Surface serial number Wide angle Telephoto end D5 1.42 13.94 D11 18.56 6.04 D21 1.79 1.65 D27 5.07 5.21

[0128] Table 7

[0129] In the second lens group G2 of the zoom lens of this embodiment, the fifth lens L5 is a plastic lens with an Abbe number of VD L5 =56.00. The sixth lens L6 is a plastic lens, and its Abbe number is VD L6 =20.40. The third lens group G3 includes two low-dispersion glass lenses, namely the eighth lens L8 and the tenth lens L10. The refractive index and Abbe number of the eighth lens L8 are: ND L8 =1.50, VD L8 =81.60; the refractive index and Abbe number of the tenth lens L10 are: ND L10 =1.44, VD L10 =95.10.

[0130] Therefore, combined with Figures 9 to 16 , and the related design parameters and data in Tables 1, 5 to 7 above, by using a variable iris and an optical structure of a four-group architecture with a specific optical power combination, the aperture of the zoom lens can reach F1.4, which can ensure the brightness of the image in a low-light environment, taking into account the imaging performance of wide field of view, small size, low cost and resolution of more than 4k. And adopting a glass-plastic hybrid lens structure, a reasonable distribution of abnormal dispersion glass lenses and high refractive index glass lenses, to achieve high-quality imaging effects, with excellent resolution, while ensuring a large magnification to achieve a small size and reduce design costs. And to maximize imaging performance in the smallest possible volume.

[0131] The zoom lens also achieves the correction of chromatic aberration and secondary spectrum in the 420-940nm band, and can ensure resolution without refocusing when switching between day and night. While taking into account infrared performance, it solves the problem of focus drift in high and low temperature environments, making the zoom lens not out of focus in the temperature range of -40℃ to 80℃, suitable for various high and low temperature environments, greatly broadening the application range of the zoom lens.

[0132] The zoom lens has low distortion throughout the zoom range, ensuring that the image is less deformed and that a wide range of object distances can be achieved. The zoom lens can ensure that the object distance from 0.1m to infinity can be clearly focused throughout the zoom range, with good imaging effects. In addition, the zoom lens has good tolerances for individual components and assembly, and has good manufacturability.

[0133] Example 3

[0134] See also Fig.17 and Fig.18 In this embodiment, the parameters of the zoom lens are as follows:

[0135] TTL = 48.25 mm;

[0136] FNO(WIDE)=1.8;

[0137] Wide-angle focal length fw = 12.5 mm;

[0138] The focal length at the telephoto end is ft=27.4mm.

[0139] The relevant parameters of each lens of the zoom lens of this embodiment include surface type, curvature radius R value, thickness d, refractive index ND and Abbe number VD of the material. Surf 1 to surf 27 represent each surface of each lens, cemented lens and aperture stop in the zoom lens, as shown in Table 8 below.

[0140]

[0141]

[0142] Table 8

[0143] In this embodiment, the aspherical lens of the zoom lens satisfies the following formula:

[0144]

[0145] Where Z represents the axial distance from the surface to the vertex at a height h perpendicular to the optical axis along the optical axis; c represents the curvature at the vertex of the aspheric surface; k represents the cone coefficient; A4, A6, A8, A 10 , A 12 They represent the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order aspheric coefficients respectively. The values ​​of the aspheric surface are shown in Table 9 below.

[0146]

[0147]

[0148] Table 9

[0149] The zoom data of the zoom lens of this embodiment is shown in Table 10 below.

[0150] Surface serial number Wide angle Telephoto end D5 0.94 13.27 D11 12.64 0.31 D21 2.43 1.55 D27 4.89 5.77

[0151] Table 10

[0152] In the second lens group G2 of the zoom lens of this embodiment, the fourth lens L4 is a plastic lens with an Abbe number of VD L4 =56.00. The sixth lens L6 is a plastic lens, and its Abbe number is VD L6 =20.4. The third lens group G3 includes two low-dispersion glass lenses, namely the seventh lens L7 and the tenth lens L10. The refractive index and Abbe number of the seventh lens L7 are: ND L7 =1.50, VD L7 =81.60; the refractive index and Abbe number of the tenth lens L10 are: ND L10 =1.44, VD L10 =95.10.

[0153] Therefore, combined with Figures 17 to 24 , and the related design parameters and data in Tables 1, 8 to 10 above, by using a variable iris and an optical structure of a four-group architecture with a specific optical power combination, the aperture of the zoom lens can reach F1.4, which can ensure the brightness of the image in a low-light environment, taking into account the imaging performance of wide field of view, small size, low cost and resolution of more than 4k. And adopting a glass-plastic hybrid lens structure, a reasonable distribution of abnormal dispersion glass lenses and high refractive index glass lenses, to achieve high-quality imaging effects, with excellent resolution, while ensuring a large magnification to achieve a small size and reduce design costs. And maximize the imaging performance in the smallest possible volume.

[0154] The zoom lens also achieves the correction of chromatic aberration and secondary spectrum in the 420-940nm band, and can ensure resolution without refocusing when switching between day and night. While taking into account infrared performance, it solves the problem of focus drift in high and low temperature environments, making the zoom lens not out of focus in the temperature range of -40℃ to 80℃, suitable for various high and low temperature environments, greatly broadening the application range of the zoom lens.

[0155] The zoom lens has low distortion throughout the zoom range, ensuring that the image is less deformed and that a wide range of object distances can be achieved. The zoom lens can ensure that the object distance from 0.1m to infinity can be clearly focused throughout the zoom range, with good imaging effects. In addition, the zoom lens has good tolerances for individual components and assembly, and has good manufacturability.

[0156] Example 4

[0157] See also Fig.25 and Fig.26 In this embodiment, the parameters of the zoom lens are as follows:

[0158] TTL = 46.87 mm;

[0159] FNO(WIDE)=1.45;

[0160] Wide-angle focal length fw = 9.6 mm;

[0161] The focal length at the telephoto end is ft=21.2mm.

[0162] The relevant parameters of each lens of the zoom lens of this embodiment include surface type, curvature radius R value, thickness d, refractive index ND and Abbe number VD of the material. Surf 1 to surf27 represent each surface of each lens, cemented lens and aperture stop in the zoom lens, as shown in Table 11 below.

[0163]

[0164]

[0165] Table 11

[0166] In this embodiment, the aspherical lens of the zoom lens satisfies the following formula:

[0167]

[0168] Where Z represents the axial distance from the surface to the vertex at a height h perpendicular to the optical axis along the optical axis; c represents the curvature at the vertex of the aspheric surface; k represents the cone coefficient; A4, A6, A8, A 10 , A 12 They represent the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order aspheric coefficients respectively. The values ​​of the aspheric surface are shown in Table 12 below.

[0169] k <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 <!-- 15 -->]]> Surf6 0 -2.12E-03 6.16E-05 1.14E-07 -5.17E-08 9.02E-10 Surf7 0 1.78E-05 -5.95E-07 9.37E-08 -3.96E-09 0.00E+00 surf10 2.2894924 9.67E-05 -1.95E-06 -8.84E-07 2.98E-08 -1.30E-09 surf11 246.0070547 -6.42E-05 1.73E-05 -3.10E-07 -2.24E-08 1.23E-10 surf15 -0.67525854 -2.38E-04 -9.82E-07 -1.18E-07 -9.36E-09 2.59E-10 surf16 3.582310688 -2.00E-04 -1.88E-06 1.47E-07 3.75E-09 -4.24E-10 surf17 -4.163196 3.70E-04 -6.51E-06 -9.13E-07 1.26E-07 -3.13E-09 surf18 1.909525669 6.17E-04 -2.94E-05 6.54E-07 6.47E-08 -2.00E-09 surf24 0 -1.46E-04 2.57E-05 -7.81E-06 7.07E-07 -1.88E-08 surf26 0 -9.78E-04 5.52E-05 -2.77E-06 -4.27E-08 0.00E+00 surf27 0 6.78E-04 9.90E-06 6.05E-07 1.61E-08 0.00E+00

[0170] Table 12

[0171] The zoom data of the zoom lens of this embodiment is shown in Table 13 below.

[0172] Surface serial number Wide angle Telephoto end D5 0.99 8.80 D11 11.37 3.56 D21 1.56 1.56 D27 4.52 4.52

[0173] Table 13

[0174] In the second lens group G2 of the zoom lens of this embodiment, the fourth lens L4 is a plastic lens with an Abbe number of VD L4 =56.00. The sixth lens L6 is a plastic lens, and its Abbe number is VD L6 =20.4. The third lens group G3 includes two low-dispersion glass lenses, namely the seventh lens L7 and the tenth lens L10. The refractive index and Abbe number of the seventh lens L7 are: ND L7 =1.50, VD L7 =81.60; the refractive index and Abbe number of the tenth lens L10 are: ND L10 =1.44, VD L10 =95.10.

[0175] Therefore, combined with Figures 25 to 32 , and the related design parameters and data in Tables 1, 11 to 13 above, by using a variable iris and an optical structure of a four-group architecture with a specific optical power combination, the aperture of the zoom lens can reach F1.4, which can ensure the brightness of the image in a low-light environment, taking into account the imaging performance of wide field of view, small size, low cost and resolution of more than 4k. And adopting a glass-plastic hybrid lens structure, a reasonable distribution of abnormal dispersion glass lenses and high refractive index glass lenses, to achieve high-quality imaging effects, with excellent resolution, while ensuring a large magnification to achieve a small size and reduce design costs. And maximize the imaging performance in the smallest possible volume.

[0176] The zoom lens also achieves the correction of chromatic aberration and secondary spectrum in the 420-940nm band, and can ensure resolution without refocusing when switching between day and night. While taking into account infrared performance, it solves the problem of focus drift in high and low temperature environments, making the zoom lens not out of focus in the temperature range of -40℃ to 80℃, suitable for various high and low temperature environments, greatly broadening the application range of the zoom lens.

[0177] The zoom lens has low distortion throughout the zoom range, ensuring that the image is less deformed and that a wide range of object distances can be achieved. The zoom lens can ensure that the object distance from 0.1m to infinity can be clearly focused throughout the zoom range, with good imaging effects. In addition, the zoom lens has good tolerances for individual components and assembly, and has good manufacturability.

[0178] Example 5

[0179] See also Fig.33 and Fig.34 In this embodiment, the parameters of the zoom lens are as follows:

[0180] TTL = 48.15 mm;

[0181] FNO(WIDE)=1.70;

[0182] Wide-angle focal length fw = 13.1 mm;

[0183] The focal length at the telephoto end is ft=24.6mm.

[0184] The relevant parameters of each lens of the zoom lens of this embodiment include surface type, curvature radius R value, thickness d, refractive index ND and Abbe number VD of the material. Surf1 to surf27 represent each surface of each lens, cemented lens and aperture stop in the zoom lens, as shown in Table 14 below.

[0185]

[0186]

[0187] Table 14

[0188] In this embodiment, the aspherical lens of the zoom lens satisfies the following formula:

[0189]

[0190] Where Z represents the axial distance from the surface to the vertex at a height h perpendicular to the optical axis along the optical axis; c represents the curvature at the vertex of the aspheric surface; k represents the cone coefficient; A4, A6, A8, A 10 , A 12 They represent the fourth-order, sixth-order, eighth-order, tenth-order, and twelfth-order aspheric coefficients respectively. The values ​​of the aspheric surface are shown in Table 15 below.

[0191] k <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> Surf6 0 -2.22E-03 4.61E-05 1.04E-07 -2.21E-08 2.57E-10 Surf7 0 3.07E-05 7.71E-08 5.53E-09 -4.54E-10 0.00E+00 surf10 2.2702834 -1.24E-05 1.12E-06 -7.78E-07 2.84E-08 -3.05E-10 surf11 18.859643 -1.65E-04 9.29E-06 -5.59E-07 4.81E-10 2.77E-10 surf15 -0.60217865 -1.01E-04 -1.21E-06 -4.11E-07 1.09E-09 9.28E-11 surf16 16.087896 2.41E-04 -7.55E-06 -2.55E-07 -2.88E-09 1.21E-10 Surf20 -1.42E+00 -1.82E-04 3.70E-05 -2.13E-07 -2.23E-08 6.01E-10 Surf21 -3.96E+00 -4.55E-04 1.01E-05 1.01E-06 -9.80E-08 3.15E-09 surf24 0 -8.68E-04 3.49E-05 -7.87E-06 5.92E-07 -1.47E-08 surf26 0 4.67E-04 2.00E-05 0.00E+00 0.00E+00 0.00E+00 surf27 0 2.14E-03 1.38E-05 2.64E-06 0.00E+00 0.00E+00

[0192] Table 15

[0193] The magnification data of the zoom lens of this embodiment is shown in Table 16 below.

[0194] Surface serial number Wide angle Telephoto end D5 0.72 11.60 D11 11.33 0.45 D21 1.54 1.55 D27 6.85 6.84

[0195] Table 16

[0196] In the second lens group G2 of the zoom lens of this embodiment, the fourth lens L4 is a plastic lens with an Abbe number of VD L4 =56.00. The sixth lens L6 is a plastic lens, and its Abbe number is VD L6 =20.40. The third lens group G3 includes two low-dispersion glass lenses, namely the seventh lens L7 and the ninth lens L9. The refractive index and Abbe number of the seventh lens L7 are: ND L7 =1.50, VDL7 =81.60; the refractive index and Abbe number of the ninth lens L9 are: ND L9 =1.44, VD L9 =95.10.

[0197] Therefore, combined with Figures 33 to 40 , and the related design parameters and data in Tables 1, 14 to 16 above, by using a variable iris and an optical structure of a four-group architecture with a specific optical power combination, the aperture of the zoom lens can reach F1.4, which can ensure the brightness of the image in a low-light environment, taking into account the imaging performance of wide field of view, small size, low cost and resolution of more than 4k. And adopting a glass-plastic hybrid lens structure, a reasonable distribution of abnormal dispersion glass lenses and high refractive index glass lenses, to achieve high-quality imaging effects, with excellent resolution, while ensuring a large magnification to achieve a small size and reduce design costs. And maximize the imaging performance in the smallest possible volume.

[0198] The zoom lens also achieves the correction of chromatic aberration and secondary spectrum in the 420-940nm band, and can ensure resolution without refocusing when switching between day and night. While taking into account infrared performance, it solves the problem of focus drift in high and low temperature environments, making the zoom lens not out of focus in the temperature range of -40℃ to 80℃, suitable for various high and low temperature environments, greatly broadening the application range of the zoom lens.

[0199] The zoom lens has low distortion throughout the zoom range, ensuring that the image is less deformed and that a wide range of object distances can be achieved. The zoom lens can ensure that the object distance from 0.1m to infinity can be clearly focused throughout the zoom range, with good imaging effects. In addition, the zoom lens has good tolerances for individual components and assembly, and has good manufacturability.

[0200] The above is only one embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A zoom lens, comprising, in order from the object side to the image side along the optical axis: A first lens group (G1) with positive focal power, a second lens group (G2) with negative focal power, an aperture (s top), a third lens group (G3) with positive focal power, and a fourth lens group (G4) with positive focal power, wherein the second lens group (G2) and the fourth lens group (G4) move along an optical axis, wherein when the zoom lens is at a telephoto end, a distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) is 12t , the distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) when the zoom lens is at the wide-angle end 12w The relationship between the focal length fw of the zoom lens at the wide-angle end is: 0.7≤(d 12t -d 12w ) / fw≤1.2; The second lens group (G2) consists of three lenses, and the focal powers of the lenses from the object side to the image side are negative focal power, negative focal power, and positive focal power, respectively; The fourth lens group (G4) consists of three lenses, and the focal powers of the lenses from the object side to the image side are positive focal power, negative focal power, and positive focal power, respectively.

2. The zoom lens according to claim 1, wherein: The first lens group (G1) consists of three lenses, and the focal powers of the lenses from the object side to the image side are negative focal power, positive focal power, and positive focal power, respectively; The image side surface of the lens closest to the image plane in the first lens group (G1) is a concave surface; The object-side surface of the lens closest to the object plane in the first lens group (G1) is convex, and the image-side surface is concave.

3. The zoom lens according to claim 1 or 2, characterized in that: The distance TTL from the first surface of the first lens group (G1) to the image plane and the diameter φ of the imaging target surface of the zoom lens satisfy the relationship: 4≤TTL / φ≤7.

5.

4. The zoom lens according to claim 1, wherein: The second lens group (G2) comprises at least two plastic lenses; The object side surface of the lens of the second lens group (G2) closest to the image plane is a convex surface.

5. The zoom lens according to claim 4, wherein: The lens of the second lens group (G2) closest to the image plane is a plastic lens.

6. The zoom lens according to claim 1, 4 or 5, characterized in that: The second lens group (G2) includes at least one lens having an Abbe number VD 21 Plastic lens that satisfies the following relationship: VD 21 ≥50; The second lens group (G2) further comprises at least one lens having an Abbe number VD 22 Plastic lens that satisfies the following relationship: VD 22 ≤30.

7. The zoom lens according to claim 1, wherein: The third lens group (G3) consists of five lenses, and the focal powers of the lenses from the object side to the image side are positive focal power, positive focal power, negative focal power, positive focal power, negative focal power, or The focal power of the lens from the object side to the image side is positive focal power, positive focal power, positive focal power, negative focal power, negative focal power; The lens closest to the image plane of the third lens group (G3) has negative optical power, and the image side surface of the lens closest to the image plane of the third lens group (G3) is a concave surface.

8. The zoom lens according to claim 1 or 7, characterized in that: The focal length f3 of the third lens group (G3) and the focal length fw of the zoom lens at the wide-angle end satisfy the relationship: 0.8≤f3 / fw≤2.

9. The zoom lens according to claim 1 or 7, characterized in that: The third lens group (G3) includes at least one low-dispersion glass lens, and the Abbe number VD and the refractive index ND of the lens satisfy the following relationship: 65≤VD≤100; 1.4≤ND≤1.

60.

10. The zoom lens according to claim 1, wherein: The fourth lens group (G4) comprises at least two plastic lenses; The lens closest to the image plane of the fourth lens group (G4) is a plastic lens.

11. The zoom lens according to claim 1, wherein: The distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) when the zoom lens is at the telephoto end 12t , the distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) when the zoom lens is at the wide-angle end 12w The distance TTL from the first surface of the first lens group (G1) to the image plane satisfies the relationship: 3≤TTL / (d 12t -d 12w )≤6.

12. The zoom lens according to claim 1, wherein: The distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) when the zoom lens is at the telephoto end 12t , the distance d from the last surface of the first lens group (G1) to the first surface of the second lens group (G2) when the zoom lens is at the wide-angle end 12w , the focal length fw of the zoom lens at the wide-angle end and the focal length ft of the zoom lens at the telephoto end satisfy the relationship: 3≤(d 12t -d 12w ) / (ft / fw)≤6.5.

Images