Zoom lens

Abstract

This invention provides a zoom lens with two lens groups, characterized in that, along the optical axis from the object side to the imaging plane, the elements are, in sequence: an aperture stop, a first lens group, a second lens group, and a filter; both the first and second lens groups include at least one lens, and both the first and second lens groups are movable along the optical axis of the zoom lens; the focal length f of the first lens group... G1 The focal length f of the second lens group G2 Satisfy: 0.7 < |f G1 / f G2 | < 1.0.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical lens, in particular to a zoom lens. BACKGROUND

[0002] With the development of smart phones, users have higher and higher requirements for the shooting level and video shooting quality of the phones. The prior art usually sets multiple fixed focus lenses to achieve the effect of optical zoom by using digital hybrid zoom and switching between lenses. However, the zoom by this way not only has unsatisfactory effect but also occupies large device space and has high cost. Continuous optical zoom not only has a longer shooting distance and a more real detail representation but also can realize a multiple zoom function to meet the shooting requirements of users in different scenes. However, such zoom lenses usually have problems of large size, low assembly yield and low imaging quality, so it is an urgent problem to design a zoom lens with high imaging quality, miniaturization and good processing characteristics. SUMMARY

[0003] In view of the above problems, the present application aims to provide a zoom lens with the advantages of high imaging quality, miniaturization and easy processing.

[0004] To solve the above problems, the present application provides a zoom lens, which has two lens groups, characterized in that, along the optical axis from the object side to the imaging surface, there are in order: a diaphragm, a first lens group, a second lens group and a filter; the first lens group and the second lens group each include at least one lens, and the first lens group and the second lens group can move along the optical axis of the zoom lens; the focal length f G1 of the first lens group and the focal length f G2 of the second lens group satisfy: 0.7 < |f G1 / f G2 | < 1.0.

[0005] Preferably, the first lens group has positive refractive power.

[0006] Preferably, the second lens group has negative refractive power.

[0007] Preferably, the first lens group includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens, and the second lens group includes a sixth lens and a seventh lens.

[0008] Preferably, the first lens has positive refractive power, and its object side surface is convex.

[0009] Preferably, the second lens has negative refractive power, and its object side surface is convex and its image side surface is concave.

[0010] Preferably, the third lens has negative focal power, and the object side surface is convex and the image side surface is concave.

[0011] Preferably, the sixth lens has positive focal power, and the object side surface is concave and the image side surface is convex.

[0012] Preferably, the seventh lens has negative focal power, and the image side surface is concave.

[0013] Preferably, the effective focal length f of the zoom lens in the wide-angle state is 2.5 < f < 3.5. W and the effective focal length f of the zoom lens in the telephoto state is 6.0 < f < 7.0. T satisfies: f T / f W ≤ 2.0.

[0014] Preferably, the maximum field angle FOV of the zoom lens in the wide-angle state is 42° ≤ FOV < 45°. W satisfies: 42° ≤ FOV < 45°. W ; the maximum field angle FOV of the zoom lens in the telephoto state is 20° ≤ FOV < 22°. T satisfies: FOV < 22°. T

[0015] Preferably, the aperture value FNO of the zoom lens satisfies: 2.5 < FNO < 4.5.

[0016] Preferably, the total track length TTL of the zoom lens in the wide-angle state is 10.0 < TTL < 12.0. W and the total track length TTL of the zoom lens in the telephoto state is 8.0 < TTL < 10.0. T satisfies: TTL W / TTL T ≤ 0.8.

[0017] Preferably, the total track length TTL of the zoom lens and the effective focal length f satisfy: 0.7 < TTL / f < 1.1.

[0018] Preferably, the real image height IH corresponding to the maximum field angle of the zoom lens and the effective focal length f satisfy: 0.35 < IH / f < 0.75.

[0019] The zoom lens provided by the present application realizes high imaging quality, miniaturization and easy processing by reasonably matching the lens shape and focal power combination between the lenses. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0021] Figure 1 FIG. 1 is a structural schematic diagram of the zoom lens in the wide-angle state according to an embodiment of the present application.

[0022] ​Figure 2 Field curvature curve for wide angle state of zoom lens in embodiment 1 of the present application.

[0023] Figure 3 F-Tanθ distortion curve for wide angle state of zoom lens in embodiment 1 of the present application.

[0024] Figure 4 MTF curve for wide angle state of zoom lens in embodiment 1 of the present application.

[0025] Figure 5 Structure schematic diagram for telephoto state of zoom lens in embodiment 1 of the present application.

[0026] Figure 6 Field curvature curve for telephoto state of zoom lens in embodiment 1 of the present application.

[0027] Figure 7 F-Tanθ distortion curve for telephoto state of zoom lens in embodiment 1 of the present application.

[0028] Figure 8 MTF curve for telephoto state of zoom lens in embodiment 1 of the present application.

[0029] Figure 9 Structure schematic diagram for wide angle state of zoom lens in embodiment 2 of the present application.

[0030] Figure 10 Field curvature curve for wide angle state of zoom lens in embodiment 2 of the present application.

[0031] Figure 11 F-Tanθ distortion curve for wide angle state of zoom lens in embodiment 2 of the present application.

[0032] Figure 12 MTF curve for wide angle state of zoom lens in embodiment 2 of the present application.

[0033] Figure 13 Structure schematic diagram for telephoto state of zoom lens in embodiment 2 of the present application.

[0034] Figure 14 Field curvature curve for telephoto state of zoom lens in embodiment 2 of the present application.

[0035] Figure 15 F-Tanθ distortion curve for telephoto state of zoom lens in embodiment 2 of the present application.

[0036] Figure 16 MTF curve for telephoto state of zoom lens in embodiment 2 of the present application.

[0037] Figure 17A structure diagram of a wide-angle state of a zoom lens in Embodiment 3 of the present application.

[0038] Figure 18 A field curvature graph of the wide-angle state of the zoom lens in Embodiment 3 of the present application.

[0039] Figure 19 An F-Tanθ distortion graph of the wide-angle state of the zoom lens in Embodiment 3 of the present application.

[0040] Figure 20 An MTF graph of the wide-angle state of the zoom lens in Embodiment 3 of the present application.

[0041] Figure 21 A structure diagram of a telephoto state of a zoom lens in Embodiment 3 of the present application.

[0042] Figure 22 A field curvature graph of the telephoto state of the zoom lens in Embodiment 3 of the present application.

[0043] Figure 23 An F-Tanθ distortion graph of the telephoto state of the zoom lens in Embodiment 3 of the present application.

[0044] Figure 24 An MTF graph of the telephoto state of the zoom lens in Embodiment 3 of the present application. DETAILED DESCRIPTION

[0045] For a better understanding of the present application, various aspects of the present application will be described in more detail below with reference to the accompanying drawings. It is to be noted that these detailed description is merely descriptive of embodiments of the present application and is not intended in any way to limit the scope of the present application. Throughout the specification, like reference numerals refer to like elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] It is to be noted that, in the present specification, the expressions first, second, third and the like are used merely to distinguish one feature from another feature, and do not indicate any limitation of the features. Thus, the first lens discussed below can also be referred to as the second lens or the third lens, without departing from the teachings of the present application.

[0047] In the drawings, the thickness, size, and shape of lenses have been exaggerated slightly for the sake of explanation. Specifically, the shape of a spherical surface or an aspherical surface shown in the drawings is shown by way of example. That is, the shape of a spherical surface or an aspherical surface is not limited to the shape of a spherical surface or an aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0048] In the present disclosure, the paraxial region refers to a region near the optical axis. If a lens surface is convex and the position of the convex surface is not specified, it means that the lens surface is convex at least in the paraxial region. If a lens surface is concave and the position of the concave surface is not specified, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is referred to as the object side surface of the lens, and the surface of each lens closest to the image plane is referred to as the image side surface of the lens.

[0049] It should also be understood that the words "comprise", "comprising", "include", "including", and / or "contain", when used in this specification, specify the presence of stated features, elements, and / or components, but do not preclude the presence or addition of one or more other features, elements, components, and / or groups thereof. In addition, when describing the embodiments of the present application, the word "may" means "one or more embodiments of the present application". Also, the word "exemplary" is intended to mean an example or an illustration.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that the terms should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0051] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0052] The zoom lens according to an embodiment of the present application sequentially includes, from the object side to the image side, a stop ST, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a filter A1.

[0053] The first lens group G1 includes:

[0054] a first lens L1 having positive refractive power, the object side surface S1 of which is convex;

[0055] a second lens L2 having negative refractive power, the object side surface S3 of which is convex and the image side surface S4 of which is concave;

[0056] a third lens L3 having negative refractive power, the object side surface S5 of which is convex and the image side surface S6 of which is concave;

[0057] a fourth lens L4 having refractive power, the object side surface S7 of which is convex;

[0058] The fifth lens L5 has negative focal power, the object side S9 is a concave surface, and the image side S10 is a convex surface.

[0059] The second lens group G2 includes:

[0060] The sixth lens L6 has positive focal power, the object side S11 is a concave surface, and the image side S12 is a convex surface.

[0061] The seventh lens L7 has negative focal power, and the image side S14 is a concave surface.

[0062] The filter A1 has an object side S15 and an image side S16.

[0063] Light from an object sequentially passes through each surface S1 to S16 and is finally imaged on the imaging surface S17.

[0064] The first lens group G1 and the second lens group G2 are movable along the optical axis, i.e., the interval distance of the first lens group G1 and the second lens group G2 on the optical axis is adjusted, for realizing optical zoom of the zoom lens between the wide-angle state and the telephoto state.

[0065] In some embodiments, the stop ST is arranged on the object side of the first lens L1, for limiting the light beam width passing through the zoom lens to reduce the influence of irrelevant light rays, which can reduce the generation of ghosting of the zoom lens and ensure the imaging quality of the zoom lens. In some embodiments, the stop ST is a variable aperture, and the aperture value of the stop ST can be adjusted in the range of 2.2 to 4.5, which can reasonably configure the light intake of the optical lens and ensure good imaging effect of the zoom lens in different scenes.

[0066] In some embodiments, the effective focal length f W of the zoom lens in the wide-angle state is less than 2.5 mm, and the effective focal length f T of the zoom lens in the telephoto state is greater than 5.5 mm. T The ratio of the effective focal length f W of the zoom lens in the wide-angle state to the effective focal length f W of the zoom lens in the telephoto state satisfies: f W < 2.0. Satisfying the above range is beneficial to increasing the difference in the field of view angle of the zoom lens, so that the zoom lens has strong zooming capability and a wide zooming range, and ensures good imaging quality of the zoom lens in different scenes.

[0067] In some embodiments, the maximum field of view angle FOV W of the zoom lens in the wide-angle state satisfies: 42° ≤ FOV W ≤ 50°, and the maximum field of view angle FOV T of the zoom lens in the telephoto state satisfies: FOV T ≤ 22°. Satisfying the above range can meet the shooting demand for a long-distance object and more effectively blur the background to highlight the focusing subject.

[0068] In some embodiments, the aperture value FNO of the zoom lens satisfies: 2.5 < FNO < 4.5. Meeting this range is beneficial for achieving large aperture characteristics, especially in telephoto mode, to achieve blurring of the foreground and background while maintaining image sharpness.

[0069] In some embodiments, the total optical length (TTL) of the zoom lens in wide-angle mode W Total optical length (TTL) in telephoto mode T Satisfy: TTL W / TTL T <0.8. Meeting the above range can effectively limit the zoom length of zoom lenses and achieve miniaturization of zoom lenses.

[0070] In some embodiments, the total optical length (TTL) and effective focal length (f) of the zoom lens satisfy the condition: 0.7 < TTL / f < 1.1. Meeting this range allows for a reduction in the overall length of the zoom lens while maintaining good image quality, thus fulfilling the requirement for miniaturization of zoom lenses.

[0071] In some embodiments, the true image height IH corresponding to the maximum field of view of the zoom lens and the effective focal length f satisfy: 0.35 < IH / f < 0.75. Satisfying the above range allows the zoom lens to not only maintain the characteristics of a large image plane, but also have good image quality.

[0072] In some embodiments, the focal length f of the first lens group of the zoom lens G1 The focal length f of the second lens group G2 Satisfy: 0.7 < |f G1 / f G2 | < 1.0. Meeting the above range, by reasonably allocating the focal lengths of the first and second lens groups, the focal length of the second lens group responsible for zoom function can be controlled within the specified range, thus improving the zoom capability of the zoom lens.

[0073] In some embodiments, the focal length f of the first lens group of the zoom lens G1 The effective focal length f satisfies: 0.5 < f G1 / f < 1.0. Meeting the above range allows the first lens group to have appropriate positive optical power, which can better balance the distortion and astigmatism of the entire zoom lens and improve the image quality of the zoom lens.

[0074] In some embodiments, the focal length f of the second lens group of the zoom lens G2 The effective focal length f satisfies: -1.25 < f G2 / f < -0.50. Meeting this range allows the second lens group to have appropriate negative optical power, enabling the acquisition of a larger image plane and improving the image quality of the zoom lens.

[0075] In some embodiments, the effective focal length f of the zoom lens and the first variable interval value CT1 satisfy: 0 < CT1 / f < 0.5. Satisfying the above range, the length of the zoom lens can be effectively limited, and miniaturization of the zoom lens can be achieved.

[0076] In some embodiments, the effective focal length f of the zoom lens and the second variable interval value CT2 satisfy: 0 < CT2 / f < 0.6. Satisfying the above range, the length of the zoom lens can be effectively limited, and miniaturization of the zoom lens can be achieved.

[0077] In some embodiments, the second variable interval value CT2 of the zoom lens satisfies: 0.0 mm < CT2 < 12.0 mm. Satisfying the above range, the second variable interval value CT2 of the zoom lens can be zero or very small in a non-working state, which is conducive to miniaturization of the zoom lens.

[0078] In order to make the system have better optical performance, a plurality of aspherical lenses are used in the lens, and each aspherical surface shape of the zoom lens satisfies the following equation:

[0079]

[0080] Wherein, z is the distance of the curved surface to the vertex of the curved surface in the direction of the optical axis, h is the distance from the optical axis to the curved surface, c is the curvature of the vertex of the curved surface, K is the quadratic surface coefficient, A, B, C, D, E, F, G, H, I, J are the second-order, fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, sixteenth-order, eighteenth-order, twentieth-order curved surface coefficients.

[0081] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature and the material selection of each lens in the zoom lens are different, and the specific differences can be referred to the parameter table of each embodiment. The following embodiments are only the preferred embodiments of the application, but the embodiments of the application are not limited to the following embodiments only, and any changes, substitutions, combinations or simplifications made without departing from the innovative points of the application should be regarded as equivalent replacement methods, and are included in the protection scope of the application.

[0082] Embodiment 1

[0083] Please refer to Figure 1 and Figure 5 , which are schematic structural diagrams of the zoom lens provided in the embodiment 1 of the application, and the zoom lens sequentially includes a diaphragm ST, a first lens group G1 with positive focal power, a second lens group G2 with negative focal power and a filter A1 along the optical axis from the object side to the imaging surface.

[0084] The first lens group G1 includes:

[0085] a first lens L1 having positive refractive power, a convex object side surface S1 and a concave image side surface S2;

[0086] a second lens L2 having negative refractive power, a convex object side surface S3 and a concave image side surface S4;

[0087] a third lens L3 having negative refractive power, a convex object side surface S5 and a concave image side surface S6;

[0088] a fourth lens L4 having positive refractive power, both the object side surface S7 and the image side surface S8 are convex;

[0089] a fifth lens L5 having negative refractive power, a concave object side surface S9 and a convex image side surface S10.

[0090] The second lens group G2 comprises:

[0091] a sixth lens L6 having positive refractive power, a concave object side surface S11 and a convex image side surface S12;

[0092] a seventh lens L7 having negative refractive power, both the object side surface S13 and the image side surface S14 are concave.

[0093] The filter A1 has an object side surface S15 and an image side surface S16.

[0094] Light from an object sequentially passes through each surface S1 to S16 and is finally imaged on an imaging surface S17.

[0095] The first lens group G1 and the second lens group G2 are movable along the optical axis, i.e. the interval distance between the first lens group G1 and the second lens group G2 along the optical axis is adjustable, for realizing optical zooming of the zoom lens between the wide-angle state and the telephoto state.

[0096] The relevant parameters of the lenses in the zoom lens in Embodiment 1 are shown in Table 1.

[0097] Table 1

[0098]

[0099]

[0100] The surface shape parameters of the aspherical lenses of the zoom lens in Embodiment 1 are shown in Table 2.

[0101] Table 2

[0102] Face number K A B C D E S1 3.43E-01 0.00E+00 -9.43E-04 2.69E-04 -9.72E-05 1.36E-05 S2 0.00E+00 0.00E+00 7.10E-04 -1.46E-03 3.92E-04 -6.08E-05 S3 0.00E+00 0.00E+00 -1.25E-02 2.87E-03 -4.96E-04 7.84E-05 S4 5.47E-02 0.00E+00 -2.61E-02 6.11E-03 -1.47E-03 2.84E-04 S5 -2.65E+00 0.00E+00 -1.45E-02 1.57E-03 -1.45E-04 7.43E-06 S6 -5.37E+00 0.00E+00 -1.68E-03 2.56E-03 1.94E-06 1.97E-05 S7 0.00E+00 0.00E+00 -9.00E-03 2.18E-03 -6.71E-04 1.54E-04 S8 0.00E+00 0.00E+00 3.70E-04 2.47E-04 -8.67E-04 3.33E-04 S9 -5.59E+00 0.00E+00 2.15E-02 4.33E-04 -5.07E-04 -1.79E-04 S10 -1.13E+00 0.00E+00 2.93E-02 2.91E-04 -1.01E-03 7.54E-05 S11 -2.54E+00 0.00E+00 8.06E-03 -6.28E-04 -1.85E-04 7.30E-05 S12 3.35E-02 0.00E+00 1.63E-02 -2.75E-03 4.67E-05 6.14E-05 S13 0.00E+00 0.00E+00 -9.17E-03 -1.82E-03 6.02E-04 -1.04E-04 S14 -1.49E+01 0.00E+00 -1.43E-02 1.67E-03 -4.74E-06 -2.50E-05 Face number K F G H I J S1 3.43E-01 -1.33E-06 9.04E-08 -8.01E-09 S2 0.00E+00 1.08E-05 -1.54E-06 7.83E-08 S3 0.00E+00 -8.43E-06 1.13E-07 1.77E-08 S4 5.47E-02 -4.22E-05 3.55E-06 -1.25E-07 S5 -2.65E+00 4.75E-06 -1.80E-06 1.83E-07 S6 -5.37E+00 -4.82E-06 -1.53E-06 9.48E-07 S7 0.00E+00 1.34E-05 8.11E-07 -6.49E-07 S8 0.00E+00 -2.75E-05 1.74E-06 2.45E-07 S9 -5.59E+00 2.46E-05 1.03E-05 -2.04E-06 S10 -1.13E+00 3.47E-06 -4.04E-06 4.08E-07 S11 -2.54E+00 -9.60E-06 5.55E-07 -1.20E-08 S12 3.35E-02 -8.73E-06 4.88E-07 -1.01E-08 S13 0.00E+00 1.19E-05 -7.13E-07 1.66E-08 S14 -1.49E+01 2.94E-06 -1.38E-07 2.34E-09

[0103] The variable interval values of the zoom lens in Embodiment 1 are shown in Table 3:

[0104] Table 3

[0105] Face number Wide angle state Telephoto state CT1 5.86 0.08 CT2 0.36 11.46

[0106] In this embodiment, the effective focal length f of the zoom lens in the wide-angle state is f = 12.94 mm, the maximum field of view FOV is FOV = 42°; the effective focal length f of the zoom lens in the telephoto state is f = 21.67 mm, the maximum field of view FOV is FOV = 22°. The zoom lens can realize continuous zooming in the focal length range of 12.94 mm to 21.67 mm. W W T T

[0107] Figure 2 A field curvature curve of the zoom lens in the wide-angle state in Embodiment 1 is shown, which represents the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.12 mm, which shows that the zoom lens in the wide-angle state can better correct the field curvature.

[0108] Figure 3 An F-Tanθ distortion curve of the zoom lens in the wide-angle state in Embodiment 1 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field of view (unit: °). It can be seen from the figure that the F-Tanθ distortion of the zoom lens is controlled within ±6%, which shows that the zoom lens in the wide-angle state can well correct the F-Tanθ distortion.

[0109] Figure 4 A modulation transfer function (MTF) curve of the zoom lens in the wide-angle state in Embodiment 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. It can be seen from the figure that the MTF value of the embodiment is above 0.4 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge field of view, and has good imaging quality and good detail resolution ability in the case of low frequency and high frequency.

[0110] Figure 6 A field curvature curve of the zoom lens in the telephoto state in Embodiment 1 is shown, which represents the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). It can be seen from the figure that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.12 mm, which shows that the zoom lens in the telephoto state can better correct the field curvature.

[0111] ​​​​Figure 7 The F-Tanθ distortion curve of the zoom lens in the long-focus state in Embodiment 1 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging plane, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the zoom lens is controlled within ±3%, which indicates that the zoom lens in the long-focus state can very well correct the F-Tanθ distortion.

[0112] Figure 8 The modulation transfer function (MTF) curve of the zoom lens in the long-focus state in Embodiment 1 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the present embodiment is above 0.2 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low and high frequency cases.

[0113] Embodiment 2

[0114] Please refer to Figure 9 and Figure 13 , which are structural schematic diagrams of the zoom lens provided in Embodiment 2 of the present application, the zoom lens sequentially includes, along the optical axis from the object side to the imaging plane: a diaphragm ST, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a filter A1.

[0115] The first lens group G1 includes:

[0116] a first lens L1 with positive refractive power, whose object side S1 and image side S2 are both convex surfaces;

[0117] a second lens L2 with negative refractive power, whose object side S3 is a convex surface and whose image side S4 is a concave surface;

[0118] a third lens L3 with negative refractive power, whose object side S5 is a convex surface and whose image side S6 is a concave surface;

[0119] a fourth lens L4 with negative refractive power, whose object side S7 is a convex surface and whose image side S8 is a concave surface;

[0120] a fifth lens L5 with negative refractive power, whose object side S9 is a concave surface and whose image side S10 is a convex surface.

[0121] The second lens group G2 includes:

[0122] a sixth lens L6 with positive refractive power, whose object side S11 is a concave surface and whose image side S12 is a convex surface;

[0123] The seventh lens L7 has a negative focal power, and both the object side surface S13 and the image side surface S14 are concave.

[0124] The filter A1 has an object side surface S15 and an image side surface S16.

[0125] Light from an object passes through the surfaces S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0126] The first lens group G1 and the second lens group G2 are movable along the optical axis, i.e. the interval distance between the first lens group G1 and the second lens group G2 along the optical axis is adjustable, for realizing optical zooming of the zoom lens between the wide-angle state and the telephoto state.

[0127] The relevant parameters of the lenses in the zoom lens in Example 2 are shown in Table 4.

[0128] Table 4

[0129]

[0130]

[0131] The surface shape parameters of the aspherical lenses of the zoom lens in Example 2 are shown in Table 5.

[0132] Table 5

[0133]

[0134]

[0135] The variable interval values of the zoom lens in Example 2 are shown in Table 6:

[0136] Table 6

[0137] Face number Wide angle state Telephoto state CT1 4.99 0.33 CT2 0.23 10.52

[0138] In this embodiment, the effective focal length f of the zoom lens in the wide-angle state is W = 12.02 mm, and the maximum field of view FOV W = 42°; the effective focal length f of the zoom lens in the telephoto state is T = 21.80 mm, and the maximum field of view FOV T = 22°. The zoom lens can realize continuous zooming in the focal length range of 12.02 mm to 21.80 mm.

[0139] Figure 10A field curvature curve of the wide-angle state of the zoom lens in Embodiment 2 is shown, which represents the bending degree of light rays of different wavelengths on the sagittal image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the sagittal image surface and the sagittal image surface is controlled within ±0.06 mm, which shows that the wide-angle state of the zoom lens can well correct the field curvature.

[0140] Figure 11 An F-Tanθ distortion curve of the wide-angle state of the zoom lens in Embodiment 2 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the zoom lens is controlled within ±10%, which shows that the wide-angle state of the zoom lens can well correct the F-Tanθ distortion.

[0141] Figure 12 A modulation transfer function (MTF) curve of the wide-angle state of the zoom lens in Embodiment 2 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.5 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has excellent imaging quality and excellent detail resolution ability in low frequency and high frequency cases.

[0142] Figure 14 A field curvature curve of the long-focus state of the zoom lens in Embodiment 2 is shown, which represents the bending degree of light rays of different wavelengths on the sagittal image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the sagittal image surface and the sagittal image surface is controlled within ±0.12 mm, which shows that the long-focus state of the zoom lens can better correct the field curvature.

[0143] Figure 15 An F-Tanθ distortion curve of the long-focus state of the zoom lens in Embodiment 2 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging surface, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the zoom lens is controlled within ±3%, which shows that the long-focus state of the zoom lens can well correct the F-Tanθ distortion.

[0144] Figure 16A modulation transfer function (MTF) curve of the zoom lens in the long-focus state in Embodiment 2 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis represents spatial frequency (unit: lp / mm), and the vertical axis represents MTF value. As can be seen from the figure, the MTF value of the embodiment is above 0.3 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in low and high frequency cases.

[0145] Embodiment 3

[0146] Please refer to Figure 17 and Figure 21 , which is a structural schematic diagram of the zoom lens provided in Embodiment 3 of the present application, which includes, along the optical axis from the object side to the imaging surface, a diaphragm ST, a first lens group G1 with positive refractive power, a second lens group G2 with negative refractive power, and a filter A1.

[0147] The first lens group G1 includes:

[0148] a first lens L1 with positive refractive power, whose object side S1 and image side S2 are both convex;

[0149] a second lens L2 with negative refractive power, whose object side S3 is convex and image side S4 is concave;

[0150] a third lens L3 with negative refractive power, whose object side S5 is convex and image side S6 is concave;

[0151] a fourth lens L4 with negative refractive power, whose object side S7 is convex and image side S8 is concave;

[0152] a fifth lens L5 with negative refractive power, whose object side S9 is concave and image side S10 is convex.

[0153] The second lens group G2 includes:

[0154] a sixth lens L6 with positive refractive power, whose object side S11 is concave and image side S12 is convex;

[0155] a seventh lens L7 with negative refractive power, whose object side S13 is convex and image side S14 is concave.

[0156] The filter A1 has an object side S15 and an image side S16.

[0157] Light from the object sequentially passes through each surface S1 to S16 and is finally imaged on the imaging surface S17.

[0158] The first lens group G1 and the second lens group G2 are movable along the optical axis, i.e. the interval distance of the first lens group G1 and the second lens group G2 along the optical axis is adjustable, for realizing optical zooming of the zoom lens between the wide-angle state and the telephoto state.

[0159] The related parameters of the lenses in the zoom lens in embodiment 3 are shown in Table 7.

[0160] Table 7

[0161]

[0162] The surface type parameters of the aspherical lenses of the zoom lens in embodiment 3 are shown in Table 8.

[0163] Table 8

[0164]

[0165]

[0166] The variable interval values of the zoom lens in embodiment 3 are shown in Table 9:

[0167] Table 9

[0168] Face number Wide angle state Telephoto state CT1 5.03 0.34 CT2 0.24 10.57

[0169] In this embodiment, the effective focal length f of the zoom lens in the wide-angle state is W = 12.07 mm, the maximum field of view FOV W = 42°; the effective focal length f of the zoom lens in the telephoto state is T = 21.81 mm, the maximum field of view FOV T = 22°. The zoom lens can realize continuous zooming in the focal length range of 12.07 mm to 21.81 mm.

[0170] Figure 18 The field curvature curve diagram of the zoom lens in the wide-angle state in embodiment 3 is shown, which represents the bending degree of light rays of different wavelengths on the meridional image surface and the sagittal image surface, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). It can be seen from the diagram that the field curvature of the meridional image surface and the sagittal image surface is controlled within ±0.05 mm, which shows that the zoom lens in the wide-angle state can correct the field curvature very well.

[0171] Figure 19The F-Tanθ distortion curve of the wide-angle state of the zoom lens in Example 3 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging plane, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the zoom lens is controlled within ±8%, which shows that the wide-angle state of the zoom lens can well correct the F-Tanθ distortion.

[0172] Figure 20 The modulation transfer function (MTF) curve of the wide-angle state of the zoom lens in Example 3 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the present embodiment is above 0.5 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has excellent imaging quality and excellent detail resolution capability in both low and high frequency cases.

[0173] Figure 22 The field curvature curve of the long-focus state of the zoom lens in Example 3 is shown, which represents the curvature of light rays of different wavelengths on the meridional image plane and the sagittal image plane, the horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.12 mm, which shows that the long-focus state of the zoom lens can better correct the field curvature.

[0174] Figure 23 The F-Tanθ distortion curve of the long-focus state of the zoom lens in Example 3 is shown, which represents the F-Tanθ distortion of light rays of different wavelengths at different image heights on the imaging plane, the horizontal axis represents the F-Tanθ distortion (unit: %), and the vertical axis represents the half field angle (unit: °). As can be seen from the figure, the F-Tanθ distortion of the zoom lens is controlled within ±3%, which shows that the long-focus state of the zoom lens can very well correct the F-Tanθ distortion.

[0175] Figure 24 The modulation transfer function (MTF) curve of the long-focus state of the zoom lens in Example 3 is shown, which represents the imaging modulation degree of the lens at different spatial frequencies in each field of view, the horizontal axis represents the spatial frequency (unit: lp / mm), and the vertical axis represents the MTF value. As can be seen from the figure, the MTF value of the present embodiment is above 0.3 in the full field of view, and in the range of 0-160 lp / mm, the MTF curve uniformly and smoothly decreases from the center to the edge of the field of view, and has better imaging quality and better detail resolution capability in both low and high frequency cases.

[0176] Please refer to Table 10 for the optical characteristics of the above-mentioned embodiments, including the effective focal length f, the total track length TTL, the F-number FNO, the image height IH, the field of view FOV of the zoom lens, and the numerical values corresponding to each conditional expression in the embodiments.

[0177] Table 10

[0178]

[0179] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0180] The above-mentioned embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A zoom lens comprising two groups of lens groups, characterized in that, In order from the object side to the imaging plane along the optical axis, there are in sequence: a diaphragm, a first lens group, a second lens group, and a filter; the first lens group and the second lens group each include at least one lens, and the first lens group and the second lens group are each movable along the optical axis of the zoom lens; focal length f of the first lens group G1 focal length f of the second lens group G2 0.7 < |f G1 / f G2 | < 1.0 The first lens group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, and the second lens group includes a sixth lens and a seventh lens. The first lens has positive refractive power, the second lens has negative refractive power, the third lens has negative refractive power, the sixth lens has positive refractive power, and the seventh lens has negative refractive power. The first lens group has positive refractive power, and the second lens group has negative refractive power.

2. The zoom lens according to claim 1, characterized by Total optical length TTL in wide angle state of zoom lens W Total optical length TTL in telephoto state T 0.69 ≤ TTL W / TTL T < 0.

8.

3. The zoom lens according to claim 1, characterized by The diaphragm is a variable aperture, and the aperture value of the diaphragm ST can be adjusted in the range of 2.2 to 4.

5.

4. The zoom lens according to claim 1, characterized by focal length f of the first lens group of the zoom lens G1 with the effective focal length f satisfying: 0.5 < f G1 / f < 1.0; focal length f of the second lens group of the zoom lens G2 with the effective focal length f satisfying: -1.25 < f G2 / f < -0.50; effective focal length f of the wide-angle state of the zoom lens W with the effective focal length f in the telephoto state T satisfying: 1.67 < f T / f W < 2.

0.

5. The zoom lens according to claim 1, characterized by The first lens has a convex object side surface.

6. The zoom lens according to claim 1, characterized by The second lens has a convex object side surface and a concave image side surface.

7. The zoom lens according to claim 1, characterized by The third lens has a convex object side surface and a concave image side surface.

8. The zoom lens according to claim 1, characterized by The sixth lens has a concave object side surface and a convex image side surface.

9. The zoom lens according to claim 1, characterized by The seventh lens has a concave image side surface.

10. The zoom lens according to claim 1, characterized by The effective focal length f of the wide-angle state of the zoom lens W The effective focal length f of the wide-angle state of the zoom lens T f T f W <2.

0.

11. The zoom lens according to claim 1, characterized by The maximum field of view FOV of the wide-angle state of the zoom lens W satisfies: 42°≤FOV W ; the maximum field of view FOV of the telephoto state T satisfies: FOV T ≤22°.

12. The zoom lens according to claim 1, characterized by The aperture value FNO of the zoom lens satisfies: 2.5 < FNO < 4.

5.

13. The zoom lens according to claim 1, characterized by Total track length TTL of the wide-angle state of the zoom lens W Total track length TTL in the telephoto state T TTL W / TTL T <0.

8.

14. The zoom lens according to claim 1, characterized by The total optical length TTL of the zoom lens and the effective focal length f satisfy: 0.7 < TTL / f < 1.

1.

15. The zoom lens according to claim 1, characterized by The real image height IH corresponding to the maximum field angle of the zoom lens and the effective focal length f satisfy: 0.35 < IH / f < 0.75.

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