Zoom lens

Abstract

The application provides a zoom lens, which comprises five lens groups in sequence along an optical axis from an object side to an imaging surface, wherein the first lens group with negative focal power comprises a first lens with negative focal power and a second lens with negative focal power; the second lens group with positive focal power comprises a third lens with focal power and a fourth lens with positive focal power; a diaphragm; the third lens group with positive focal power comprises a fifth lens with positive focal power; the fourth lens group with positive focal power comprises a sixth lens with positive focal power and a seventh lens with positive focal power; and the fifth lens group with positive focal power comprises an eighth lens with positive focal power, a ninth lens with negative focal power, a tenth lens with positive focal power and an eleventh lens with negative focal power. The zoom lens has the advantages of large field of view, large aperture, high pixel and miniaturization.

Description

TECHNICAL FIELD

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

[0002] With the continuous advancement of technology, consumers have increasingly high requirements for security lenses. Wide-angle zoom lenses are increasingly popular in the security market because, on the one hand, they can be used in a variety of monitoring scenarios due to their variable focal length, and on the other hand, they can monitor a larger range of targets due to their large field of view. However, the aperture of the wide-angle zoom lens is usually not very large, with a maximum aperture of only F1.6~F1.8, and the focusing difficulty and axial aberration correction difficulty of the wide-angle zoom lens are multiplied as the aperture increases. SUMMARY

[0003] To solve the above problems, the present application aims to provide a zoom lens that has the advantages of large field of view, large aperture, high pixels, and miniaturization.

[0004] To achieve the above-mentioned purposes, the technical solutions of the present application are as follows:

[0005] A zoom lens, which has five lens groups, is arranged along the optical axis from the object side to the imaging surface in the following order:

[0006] The first lens group with negative refractive power comprises: a first lens with negative refractive power, and a second lens with negative refractive power;

[0007] The second lens group with positive refractive power comprises: a third lens with refractive power, and a fourth lens with positive refractive power;

[0008] A diaphragm;

[0009] The third lens group with positive refractive power comprises: a fifth lens with positive refractive power;

[0010] The fourth lens group with positive refractive power comprises: a sixth lens with positive refractive power, and a seventh lens with positive refractive power;

[0011] The fifth lens group with positive refractive power comprises: an eighth lens with positive refractive power, a ninth lens with negative refractive power, a tenth lens with positive refractive power, and an eleventh lens with negative refractive power.

[0012] Preferably, the effective focal length f W of the zoom lens in the wide-angle state is less than T the effective focal length f T of the zoom lens in the telephoto state. W f

[0013] Preferably, the effective focal length f of the zoom lens and the total optical length TTL satisfy: 8.0 < TTL / f < 24.0.

[0014] Preferably, the total optical length TTL of the zoom lens and the true image height IH corresponding to the maximum field of view satisfy: 8.0 < TTL / IH < 10.0.

[0015] Preferably, the effective focal length f of the zoom lens in wide-angle mode is... W And the effective focal length f in telephoto mode T The true image height IH corresponding to the maximum field of view angle satisfies: 2.0 < IH / f W <2.4, 1.0 < IH / f T <1.3.

[0016] Preferably, the total optical length (TTL) and the optical back focal length (BFL) of the zoom lens satisfy the condition: 0.02 ≤ BFL / TTL.

[0017] Preferably, the effective focal length f of the zoom lens in wide-angle mode is... W The focal length f of the first lens group G1 Satisfy: -5.0 < f G1 / f W <-1.0.

[0018] Preferably, the effective focal length f of the zoom lens in wide-angle mode is... W The focal length f of the fifth lens group G5 Satisfy: 12 < |f G5 / f W |

[0019] Preferably, the effective focal length f of the zoom lens in wide-angle mode is... W The distance CT between the first lens group and the second lens group on the optical axis 12 Satisfy: 5.0 < CT 12 / f W <6.5.

[0020] Preferably, the effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy: -0.8 < f2 / f3 < -1.2.

[0021] Compared with the prior art, the beneficial effects of the present invention are: the zoom lens of this application achieves the advantages of large field of view, large aperture, high pixel count and miniaturization by reasonably matching the lens shape and optical power combination of each lens.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0024] Figure 1 This is a schematic diagram of the zoom lens in its wide-angle state according to Embodiment 1 of the present invention;

[0025] Figure 2 This is a field curvature curve diagram of the zoom lens in the wide-angle state in Embodiment 1 of the present invention;

[0026] Figure 3 This is the F-tanθ distortion curve of the zoom lens in the wide-angle state in Embodiment 1 of the present invention;

[0027] Figure 4 This is the MTF curve of the zoom lens in the wide-angle state in Embodiment 1 of the present invention;

[0028] Figure 5 This is a schematic diagram of the zoom lens in telephoto mode in Embodiment 1 of the present invention;

[0029] Figure 6 This is a field curvature curve diagram of the zoom lens in telephoto state in Embodiment 1 of the present invention;

[0030] Figure 7 This is the F-tanθ distortion curve of the zoom lens in telephoto mode in Embodiment 1 of the present invention;

[0031] Figure 8 This is an MTF curve of the zoom lens in telephoto mode in Embodiment 1 of the present invention;

[0032] Figure 9 This is a schematic diagram of the zoom lens in its wide-angle state in Embodiment 2 of the present invention;

[0033] Figure 10 This is a field curvature curve diagram of the zoom lens in the wide-angle state in Embodiment 2 of the present invention;

[0034] Figure 11 This is the F-tanθ distortion curve of the zoom lens in the wide-angle state in Embodiment 2 of the present invention;

[0035] Figure 12 This is the MTF curve of the zoom lens in the wide-angle state in Embodiment 2 of the present invention;

[0036] Figure 13 This is a schematic diagram of the zoom lens in telephoto mode in Embodiment 2 of the present invention;

[0037] Figure 14 This is a field curvature curve diagram of the zoom lens in telephoto mode in Embodiment 2 of the present invention;

[0038] Figure 15 F-tanθ distortion curve of the zoom lens in the wide-angle state of the embodiment 1 of the present application;

[0039] Figure 16 MTF curve of the zoom lens in the wide-angle state of the embodiment 1 of the present application;

[0040] Figure 17 Structure diagram of the zoom lens in the wide-angle state of the embodiment 3 of the present application;

[0041] Figure 18 Curvature of field curve of the zoom lens in the wide-angle state of the embodiment 3 of the present application;

[0042] Figure 19 F-tanθ distortion curve of the zoom lens in the wide-angle state of the embodiment 3 of the present application;

[0043] Figure 20 MTF curve of the zoom lens in the wide-angle state of the embodiment 3 of the present application;

[0044] Figure 21 Structure diagram of the zoom lens in the long-focus state of the embodiment 3 of the present application;

[0045] Figure 22 Curvature of field curve of the zoom lens in the long-focus state of the embodiment 3 of the present application;

[0046] Figure 23 F-tanθ distortion curve of the zoom lens in the long-focus state of the embodiment 3 of the present application;

[0047] Figure 24 MTF curve of the zoom lens in the long-focus state of the embodiment 3 of the present application.

[0048] The following detailed description will further describe the present application with reference to the above-mentioned drawings. DETAILED DESCRIPTION

[0049] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It is to be understood that the detailed description is merely descriptive of embodiments of the present application and is not intended to limit the scope of the present application in any way. 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.

[0050] It should be noted that, in the present specification, the expressions first, second, third, and the like are merely used to distinguish one feature from another feature, and do not represent any limitation on 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.

[0051] In the drawings, the thickness, size, and shape of the lenses have been exaggerated slightly for ease of explanation. Specifically, the shape of the spherical or aspherical surface shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The drawings are merely examples and are not drawn to scale.

[0052] In this context, the paraxial region refers to a region near the optical axis. If the 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 the 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.

[0053] 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. Furthermore, when describing the embodiments of the present application, the use of "may" means that one or more embodiments of the present application. Also, the word "exemplary" is intended to mean an example or an illustration.

[0054] 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.

[0055] 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.

[0056] The zoom lens according to an embodiment of the present application sequentially includes, from the object side to the image side, a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, a stop ST, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, and a filter A1 and a protective glass A2.

[0057] The first lens group G1 comprises: a first lens with negative focal length, whose object side surface is convex and whose image side surface is concave; and a second lens with negative focal length, whose object side surface is convex and whose image side surface is concave.

[0058] The second lens group G2 comprises: a third lens with positive focal length, whose object side surface is convex and whose image side surface is concave; and a fourth lens with positive focal length, whose object side surface and image side surface are both convex.

[0059] The third lens group G3 comprises: a fifth lens with positive focal length, whose object side surface and image side surface are both convex.

[0060] The fourth lens group G4 comprises: a sixth lens with positive focal length, whose object side surface and image side surface are both convex; and a seventh lens with positive focal length, whose object side surface is concave and whose image side surface is convex.

[0061] The fifth lens group G5 comprises: an eighth lens with positive focal length, whose object side surface and image side surface are both convex; a ninth lens with negative focal length, whose object side surface and image side surface are both concave; a tenth lens with positive focal length, whose object side surface and image side surface are both convex; and an eleventh lens with negative focal length, whose object side surface is convex and whose image side surface is concave.

[0062] The second lens group G2, the third lens group G3 and the fourth lens group G4 are movable along the optical axis, for realizing optical zooming of the zoom lens between the wide-angle state and the telephoto state, and the fifth lens group G5 is movable along the optical axis, for compensating for the change in the image plane position of the zoom lens during the optical zooming.

[0063] In some embodiments, a diaphragm for limiting the light beam can be arranged between the second lens group G2 and the third lens group G3, which can reduce the generation of ghost images of the zoom lens, is conducive to converging the light rays entering the optical system, and reduces the back aperture of the zoom lens; and the diaphragm is arranged in this way, which can also make the zoom lens have a larger aperture, so as to realize the performance requirement of a large aperture of the zoom lens.

[0064] In some embodiments, the effective focal length f W and the effective focal length f T satisfy: f T / f W < 2.0. Satisfying the above range can control the zoom ratio of the zoom lens, is conducive to realizing continuous zooming, and ensures that the zoom lens has good imaging quality in different scenes.

[0065] In some embodiments, the effective focal length f of the zoom lens and the total optical length TTL satisfy: 8.0 < TTL / f < 24.0. Satisfying the above range can effectively limit the length of the zoom lens, and realize miniaturization of the zoom lens.

[0066] In some embodiments, the total optical length TTL of the zoom lens and the real image height IH corresponding to the maximum field of view angle satisfy: 8.0 < TTL / IH < 10.0. Satisfying the above range, while good imaging quality is taken into account, the total length of the zoom lens is shortened, miniaturization of the zoom lens is realized, and the demand for miniaturization and large image surface in the security monitoring application scenario is met.

[0067] In some embodiments, the effective focal length f W and the effective focal length f T of the zoom lens in the telephoto state satisfy: 2.0 < IH / f W < 2.4, and 1.0 < IH / f T < 1.3. Satisfying the above range, the demand for mainstream field of view angle in the security monitoring application scenario can be met.

[0068] In some embodiments, the total optical length TTL of the zoom lens and the optical back focal length BFL satisfy: 0.02 ≤ BFL / TTL. Satisfying the above range, a balance between good imaging quality and easy-to-assemble optical back focal length length is achieved, the imaging quality of the zoom lens is ensured, and the difficulty of camera module assembly process is reduced.

[0069] In some embodiments, the effective focal length f W of the zoom lens in the wide-angle state and the focal length f G1 of the first lens group G1 satisfy: -5.0 < f G1 / f W < -1.0. Satisfying the above range, by reasonably allocating the focal lengths of the lenses of the first lens group, the incident angle of the incident light is reduced, the light can enter the rear zoom lens correctly and smoothly, and the imaging quality of the zoom lens is improved.

[0070] In some embodiments, the effective focal length f W of the zoom lens in the wide-angle state and the focal length f G2 of the second lens group G2 satisfy: 7.0 < f G2 / f W < 9.0. Satisfying the above range, by reasonably allocating the focal lengths of the lenses of the second lens group, the angle of the incident light is compressed, the light transitions smoothly, and the aperture of the rear lens is reduced.

[0071] In some embodiments, the effective focal length f W of the zoom lens in the wide-angle state and the focal length f G3 of the third lens group G3 satisfy: 6.0 < f G3 / f W<7.0. Satisfying the above range, by reasonably distributing the focal lengths of the lenses of the fourth lens group, more light rays can be collected into the rear optical system to increase the light throughput, which is conducive to achieving higher imaging quality.

[0072] In some embodiments, the effective focal length f W The focal length f G4 Satisfies: 4.0 < f G4 / f W <7.0. Satisfying the above range, by reasonably distributing the focal lengths of the lenses of the fourth lens group, more light rays can be collected into the rear optical system to increase the light throughput, which is conducive to achieving higher imaging quality.

[0073] In some embodiments, the effective focal length f W The focal length f G5 Satisfies: 12 < |f G5 / f W |. Satisfying the above range, by reasonably distributing the focal lengths of the lenses of the fifth lens group, the angle of the outgoing light can be controlled, which can make the allowable error value between the CRA of the zoom lens and the CRA of the chip photosensitive element larger, and improve the adaptation ability of the zoom lens to the image sensor.

[0074] In some embodiments, the effective focal length f W The distance CT on the optical axis between the first lens group G1 and the second lens group G2 12 Satisfies: 5.0 < CT 12 / f W <6.5. Satisfying the above range can effectively limit the length of the zoom lens, and realize the miniaturization of the zoom lens.

[0075] In some embodiments, the effective focal length f T The distance CT on the optical axis between the second lens group G2 and the third lens group G3 23 Satisfies: 0.6 < CT 23 / f T <1.4. Satisfying the above range can effectively limit the length of the zoom lens, and realize the miniaturization of the zoom lens.

[0076] In order to make the system have better optical performance, multiple aspherical lenses are used in the lens, and the shape of each aspherical surface of the zoom lens satisfies the following equation:

[0077]

[0078] Wherein, z is the distance of the curved surface and the curved surface vertex in the direction of the optical axis, h is the distance of the optical axis to the curved surface, c is the curvature of the curved surface vertex, K is the quadratic curved surface coefficient, A, B, C, D, E, F, G, H are respectively the second order, fourth order, sixth order, eighth order, tenth order, twelfth order, fourteenth order, sixteenth order curved surface coefficient.

[0079] The application will be further described in the following embodiments. In each embodiment, the thickness, the radius of curvature, 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, any change, replacement, combination or simplification made without departing from the innovative points of the application should be regarded as equivalent replacement mode, and all are included in the protection scope of the application.

[0080] Embodiment 1

[0081] Please refer to Figure 1 and Figure 5 , which are the structural schematic diagram of the zoom lens provided in the embodiment 1 of the application, the zoom lens sequentially comprises, along the optical axis from the object side to the imaging surface: the first lens group G1 with negative focal power, the second lens group G2 with positive focal power, the diaphragm ST, the third lens group G3 with positive focal power, the fourth lens group G4 with positive focal power, the fifth lens group G5 with positive focal power, and the filter A1 and the protection glass A2.

[0082] The first lens group G1 comprises: the first lens L1 with negative focal power, the object side surface S1 of which is a convex surface, and the image side surface S2 of which is a concave surface; the second lens L2 with negative focal power, the object side surface S3 of which is a convex surface, and the image side surface S4 of which is a concave surface.

[0083] The second lens group G2 comprises: the third lens L3 with positive focal power, the object side surface S5 of which is a convex surface, and the image side surface S6 of which is a concave surface; the fourth lens L4 with positive focal power, the object side surface S7 and the image side surface S8 of which are both convex surfaces.

[0084] The third lens group G3 comprises: the fifth lens L5 with positive focal power, the object side surface S9 and the image side surface S10 of which are both convex surfaces.

[0085] The fourth lens group G4 comprises: the sixth lens L6 with positive focal power, the object side surface S11 and the image side surface S12 of which are both convex surfaces; the seventh lens L7 with positive focal power, the object side surface S13 of which is a concave surface, and the image side surface S14 of which is a convex surface.

[0086] The fifth lens group G5 includes: an eighth lens L8 with positive refractive power, whose object side surface S15 and image side surface S16 are both convex surfaces; a ninth lens L9 with negative refractive power, whose object side surface S17 and image side surface S18 are both concave surfaces; a tenth lens L10 with positive refractive power, whose object side surface S19 and image side surface S20 are both convex surfaces; and an eleventh lens L11 with negative refractive power, whose object side surface S21 is a convex surface and whose image side surface S22 is a concave surface.

[0087] The second lens group G2, the third lens group G3 and the fourth lens group G4 are movable along the optical axis for realizing optical zooming of the zoom lens between the wide-angle state and the telephoto state, and the fifth lens group G5 is movable along the optical axis for compensating the change of the image plane position during the optical zooming of the zoom lens.

[0088] The object side surface S23 and the image side surface S24 of the filter A1 are both planar surfaces.

[0089] The object side surface S25 and the image side surface S26 of the protective glass A2 are both planar surfaces.

[0090] The imaging surface S27 is a planar surface.

[0091] The related parameters of the lenses in the zoom lens in Embodiment 1 are shown in Table 1-1.

[0092] Table 1-1

[0093]

[0094] The surface type parameters of the aspherical lenses in the zoom lens in Embodiment 1 are shown in Table 1-2.

[0095] Table 1-2

[0096]

[0097] The variable interval values of the zoom lens in Embodiment 1 are shown in Table 1-3.

[0098] Table 1-3

[0099]

[0100] Figure 2 The field curvature curve of the zoom lens in Embodiment 1 in the wide-angle state is shown, which represents the bending degree of the light rays with 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 ±0.04 mm, which shows that the zoom lens can correct the field curvature very well in the wide-angle state.

[0101] Figure 3F-tanθ distortion curve of the wide-angle state of the zoom lens in Example 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 F-tanθ distortion (unit: %), and the vertical axis represents half field angle (unit: °). As can be seen from the figure, the F-tanθ distortion of the zoom lens is controlled within ±5%, which shows that the zoom lens can well correct F-tanθ distortion in the wide-angle state.

[0102] Figure 4 MTF (Modulation Transfer Function) curve of the wide-angle state of the zoom lens in Example 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 spatial frequency (unit: lp / mm), and the vertical axis represents 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 good imaging quality and good detail resolution ability in both low and high frequency cases.

[0103] Figure 6 Field curvature curve of the long-focus state of the zoom lens in Example 1 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 offset (unit: mm), and the vertical axis represents 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 ±0.03 mm, which shows that the zoom lens can well correct the field curvature in the long-focus state.

[0104] Figure 7 F-tanθ distortion curve of the long-focus state of the zoom lens in Example 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 F-tanθ distortion (unit: %), and the vertical axis represents half field angle (unit: °). As can be seen from the figure, the F-tanθ distortion of the zoom lens is controlled within ±20%, which shows that the zoom lens can better correct F-tanθ distortion in the long-focus state.

[0105] Figure 8 MTF (Modulation Transfer Function) curve of the long-focus state of the zoom lens in Example 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 spatial frequency (unit: lp / mm), and the vertical axis represents 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 good imaging quality and good detail resolution ability in both low and high frequency cases.

[0106] Example 2

[0107] Referring to Figure 9 and Figure 13 , a schematic structural diagram of a zoom lens provided in Embodiment 2 of the present application is shown, which comprises, in order from the object side to the imaging plane along the optical axis, a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a diaphragm ST, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with positive refractive power, and a filter A1 and a protective glass A2.

[0108] The first lens group G1 comprises a first lens L1 with negative refractive power, whose object side S1 is a convex surface and whose image side S2 is a concave surface; and 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.

[0109] The second lens group G2 comprises 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; and a fourth lens L4 with positive refractive power, whose object side S7 and image side S8 are both convex surfaces.

[0110] The third lens group G3 comprises a fifth lens L5 with positive refractive power, whose object side S9 and image side S10 are both convex surfaces.

[0111] The fourth lens group G4 comprises a sixth lens L6 with positive refractive power, whose object side S11 and image side S12 are both convex surfaces; and a seventh lens L7 with positive refractive power, whose object side S13 is a concave surface and whose image side S14 is a convex surface.

[0112] The fifth lens group G5 comprises an eighth lens L8 with positive refractive power, whose object side S15 and image side S16 are both convex surfaces; a ninth lens L9 with negative refractive power, whose object side S17 and image side S18 are both concave surfaces; a tenth lens L10 with positive refractive power, whose object side S19 and image side S20 are both convex surfaces; and an eleventh lens L11 with negative refractive power, whose object side S21 is a convex surface and whose image side S22 is a concave surface.

[0113] Among them, the second lens group G2, the third lens group G3 and the fourth lens group G4 can move along the optical axis to realize the optical zoom of the zoom lens between the wide-angle state and the long-focus state, and the fifth lens group G5 can move along the optical axis to compensate for the change of the image plane position of the zoom lens during the optical zoom.

[0114] The related parameters of each lens in the zoom lens in Embodiment 2 are shown in Table 2-1.

[0115] Table 2-1

[0116]

[0117] The surface shape parameters of the aspherical lenses of the zoom lens in Example 2 are shown in Table 2-2.

[0118] Table 2-2

[0119]

[0120] The variable spacing values of the zoom lens in Example 2 are shown in Table 2-3.

[0121] Table 2-3

[0122]

[0123] Figure 10 A field curvature curve of the zoom lens in wide-angle state in Example 2 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 angle (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 ±0.04 mm, which shows that the zoom lens in wide-angle state can correct the field curvature very well.

[0124] Figure 11 An F-tanθ distortion curve of the zoom lens in wide-angle state in Example 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: °). It can be seen from the figure that the F-tanθ distortion of the zoom lens is controlled within ±5%, which shows that the zoom lens in wide-angle state can correct the F-tanθ distortion very well.

[0125] Figure 12 An MTF (Modulation Transfer Function) curve of the zoom lens in wide-angle state in Example 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 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 present embodiment is above 0.5 within 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.

[0126] Figure 14 A field curvature curve of the zoom lens in telephoto state in Example 2 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 angle (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 ±0.03 mm, which shows that the zoom lens in telephoto state can correct the field curvature very well.

[0127] Figure 15 The F-tanθ distortion curve of the zoom lens in the long-focus state in Embodiment 2 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 ±20%, which shows that the zoom lens in the long-focus state can better correct the F-tanθ distortion.

[0128] Figure 16 The MTF (Modulation Transfer Function) 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 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 good imaging quality and good detail resolution ability in both low and high frequency cases.

[0129] Embodiment 3

[0130] Please refer to Figure 17 and Figure 21 , which are structural schematic diagrams of the zoom lens provided in Embodiment 3 of the present application, the zoom lens includes, along the optical axis from the object side to the imaging plane, a first lens group G1 with negative refractive power, a second lens group G2 with positive refractive power, a stop ST, a third lens group G3 with positive refractive power, a fourth lens group G4 with positive refractive power, a fifth lens group G5 with positive refractive power, and a filter A1 and a protective glass A2.

[0131] The first lens group G1 includes a first lens L1 with negative refractive power, whose object side S1 is a convex surface and whose image side S2 is a concave surface; and 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.

[0132] The second lens group G2 includes 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; and a fourth lens L4 with positive refractive power, whose object side S7 and image side S8 are both convex surfaces.

[0133] The third lens group G3 includes a fifth lens L5 with positive refractive power, whose object side S9 and image side S10 are both convex surfaces.

[0134] The fourth lens group G4 includes a sixth lens L6 with positive refractive power, whose object side S11 and image side S12 are both convex surfaces; and a seventh lens L7 with positive refractive power, whose object side S13 is a concave surface and whose image side S14 is a convex surface.

[0135] The fifth lens group G5 includes: an eighth lens L8 with positive refractive power, whose object side surface S15 and image side surface S16 are both convex; a ninth lens L9 with negative refractive power, whose object side surface S17 and image side surface S18 are both concave; a tenth lens L10 with positive refractive power, whose object side surface S19 and image side surface S20 are both convex; and an eleventh lens L11 with negative refractive power, whose object side surface S21 is convex and whose image side surface S22 is concave.

[0136] The second lens group G2, the third lens group G3 and the fourth lens group G4 are movable along the optical axis for realizing optical zooming of the zoom lens between the wide-angle state and the telephoto state, and the fifth lens group G5 is movable along the optical axis for compensating the change of the image surface position during the optical zooming of the zoom lens.

[0137] The related parameters of the lenses in the zoom lens in Embodiment 3 are shown in Table 3-1.

[0138] Table 3-1

[0139]

[0140] The surface type parameters of the aspherical lenses in the zoom lens in Embodiment 3 are shown in Table 3-2.

[0141] Table 3-2

[0142]

[0143] The variable interval values of the zoom lens in Embodiment 3 are shown in Table 3-3.

[0144] Table 3-3

[0145]

[0146] Figure 18 The field curvature curve diagram of the wide-angle state of the zoom lens in Embodiment 3 is shown, which represents the bending degree of light rays with 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 angle (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 ±0.04 mm, which indicates that the wide-angle state of the zoom lens can well correct the field curvature.

[0147] Figure 19The F-tanθ distortion curve of the wide-angle state of the zoom lens in Embodiment 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 ±5%, which shows that the wide-angle state of the zoom lens can very well correct the F-tanθ distortion.

[0148] Figure 20 The MTF (Modulation Transfer Function) curve of the wide-angle state of the zoom lens in Embodiment 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 good imaging quality and good detail resolution ability in both low and high frequency cases.

[0149] Figure 22 The field curvature curve of the long-focus state of the zoom lens in Embodiment 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 ±0.03 mm, which shows that the long-focus state of the zoom lens can very well correct the field curvature.

[0150] Figure 23 The F-tanθ distortion curve of the long-focus state of the zoom lens in Embodiment 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 ±20%, which shows that the long-focus state of the zoom lens can better correct the F-tanθ distortion.

[0151] Figure 24 The MTF (Modulation Transfer Function) curve of the long-focus state of the zoom lens in Embodiment 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 good imaging quality and good detail resolution ability in both low and high frequency cases.

[0152] Please refer to Table 4 for the optical characteristics of the above-mentioned embodiments, including the effective focal length f, the total track length TTL, the aperture value FNO, the image height IH, and the maximum field angle FOV of the zoom lens, and the numerical values corresponding to each conditional expression in the embodiments.

[0153] Table 4

[0154]

[0155] In summary, the zoom lens of the embodiments of the present application realizes the advantages of large field of view, large aperture, high pixel, and miniaturization by reasonably matching the lens shape and power combination between each lens.

[0156] In the description of the present specification, the description referring to 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 description of the above terms does 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.

[0157] The above-mentioned embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the 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 should be subject to the appended claims.

Claims

1. A zoom lens, comprising five lens groups, characterized in that, Along the optical axis from the object side to the imaging plane, the order is as follows: The first lens group with negative optical power includes: a first lens with negative optical power and a second lens with negative optical power; The second lens group with positive optical power includes: a third lens with optical power and a fourth lens with positive optical power; Aperture; The third lens group with positive optical power includes: a fifth lens with positive optical power; The fourth lens group with positive optical power includes: a sixth lens with positive optical power and a seventh lens with positive optical power; The fifth lens group with positive optical power includes: an eighth lens with positive optical power, a ninth lens with negative optical power, a tenth lens with positive optical power, and an eleventh lens with negative optical power. The second, third, and fourth lens groups can move along the optical axis to achieve optical zoom between wide-angle and telephoto states. The fifth lens group can move along the optical axis to compensate for changes in the image plane position during optical zoom.

2. The zoom lens according to claim 1, characterized in that, The effective focal length f of the zoom lens in wide-angle mode W With the effective focal length f in telephoto mode T Satisfy: f T / f W <2.

0.

3. The zoom lens according to claim 1, characterized in that, The effective focal length f and the total optical length TTL of the zoom lens satisfy the following condition: 8.0 < TTL / f < 24.

0.

4. The zoom lens according to claim 1, characterized in that, The total optical length TTL of the zoom lens and the true image height IH corresponding to the maximum field of view satisfy the following condition: 8.0 < TTL / IH < 10.

0.

5. The zoom lens according to claim 1, characterized in that, The effective focal length f of the zoom lens in wide-angle mode W And the effective focal length f in telephoto mode T The true image height IH corresponding to the maximum field of view angle satisfies: 2.0 < IH / f W <2.4, 1.0 < IH / f T <1.

3.

6. The zoom lens according to claim 1, characterized in that, The effective focal length f of a zoom lens in wide-angle mode W The focal length f of the second lens group G2 Satisfy: 7.0 < f G2 / f W <9.

0.

7. The zoom lens according to claim 1, characterized in that, The effective focal length f of the zoom lens in wide-angle mode W The focal length f of the first lens group G1 Satisfy: -5.0 < f G1 / f W <-1.

0.

8. The zoom lens according to claim 1, characterized in that, The effective focal length f of the zoom lens in wide-angle mode W The focal length f of the fifth lens group G5 Satisfy: 12 < |f G5 / f W | 9. The zoom lens according to claim 1, characterized in that, The effective focal length f of the zoom lens in wide-angle mode W The distance CT between the first lens group and the second lens group on the optical axis 12 Satisfy: 5.0 < CT 12 / f W <6.

5.

10. The zoom lens according to claim 1, characterized in that, The effective focal length f2 of the second lens and the effective focal length f3 of the third lens satisfy: -0.8 < f2 / f3 < -1.2.

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