Zoom lens set

Abstract

The present application discloses a zoom lens group, which includes, in order from the object side to the image side along the optical axis: a first lens group with negative optical power, which includes a first lens and a second lens, wherein the first lens has positive optical power, and its object side surface is convex, and its image side surface is concave; a second lens group with positive optical power, which includes a third lens and a fourth lens; a third lens group with optical power, which includes a fifth lens and a sixth lens, wherein the fifth lens and the sixth lens form a cemented lens; and a fourth lens group with optical power, which includes a seventh lens. The spacing distance between the first lens group and the second lens group on the optical axis, the spacing distance between the second lens group and the third lens group on the optical axis, and the spacing distance between the third lens group and the fourth lens group on the optical axis are changed to realize the switching of the zoom lens group from a telephoto state to a wide-angle state.

Description

Technical Field

[0001] The present application relates to the field of optical elements, and in particular, to a zoom lens assembly. Background Art

[0002] With the development of camera technology and the rise of the Internet industry, users have higher and higher requirements for the photography level and quality of mobile devices such as smartphones and camcorders. At present, the method generally used by lens manufacturers in this field to optimize the imaging quality of lenses is to use a combination of ultra-clear main camera, ultra-wide angle, and telephoto lenses. However, this combination of lenses on the market currently requires switching different lenses to complete the zoom when shooting different scenes. For example, the zoom of the current rear camera is mostly a "baton" zoom, that is, the "continuous" zoom is achieved by switching between wide-angle-main camera-telephoto in a non-true optical sense. In addition, installing multiple lenses in a mobile device will not only greatly occupy the internal space of the mobile device, but also cause many problems such as high cost, large size, and a significant increase in weight.

[0003] How to achieve "continuous" zoom in a true optical sense and effectively ensure that the zoom lens group has the characteristics of low cost, small size, light weight, and smooth image transition during the optical zoom process is one of the key issues that many optical lens designers need to solve urgently. Summary of the invention

[0004] On one hand, the present application provides such a zoom lens group, which includes, in order from the object side to the image side along the optical axis: a first lens group with negative optical power, which includes a first lens and a second lens, wherein the first lens has positive optical power, and its object side surface is convex, and its image side surface is concave; a second lens group with positive optical power, which includes a third lens and a fourth lens; a third lens group with optical power, which includes a fifth lens and a sixth lens, wherein the fifth lens and the sixth lens form a cemented lens; and a fourth lens group with optical power, which includes a seventh lens. The switching of the zoom lens group from a telephoto state to a wide-angle state can be achieved by changing the spacing distance between the first lens group and the second lens group on the optical axis, the spacing distance between the second lens group and the third lens group on the optical axis, and the spacing distance between the third lens group and the fourth lens group on the optical axis.

[0005] In one embodiment, there is at least one aspherical mirror surface from the object side surface of the first lens to the image side surface of the seventh lens.

[0006] In one embodiment, the total effective focal length FT of the zoom lens group when it is in a telephoto state and the total effective focal length FW of the zoom lens group when it is in a wide-angle state may satisfy: 1.9<FT / FW<2.9.

[0007] In one embodiment, the effective focal length F1 of the first lens group and the effective focal length F2 of the second lens group may satisfy: -2.9<F1 / F2<-1.6.

[0008] In one embodiment, the total effective focal length FT of the zoom lens group in the telephoto state may satisfy: 29 mm < FT < 36 mm.

[0009] In one embodiment, the curvature radius R1 of the object side surface of the first lens, the curvature radius R2 of the image side surface of the first lens, and the total effective focal length FW of the zoom lens group in a wide-angle state may satisfy: 1.0<(R1+R2) / FW<1.5.

[0010] In one embodiment, the effective focal length f11 of the first lens, the effective focal length f12 of the second lens, and the effective focal length f31 of the fifth lens may satisfy: 0.8<(f11+f12) / f31<1.3.

[0011] In one embodiment, the effective focal length f21 of the third lens and the curvature radius R5 of the object-side surface of the third lens may satisfy: 0.8<f21 / R5<1.3.

[0012] In one embodiment, a center thickness CT1 of the first lens on the optical axis and a center thickness CT7 of the seventh lens on the optical axis may satisfy: 1.0<CT1 / CT7<2.8.

[0013] In one embodiment, a curvature radius R13 of the object-side surface of the seventh lens and a curvature radius R14 of the image-side surface of the seventh lens may satisfy: 0.5<R13 / R14<1.0.

[0014] In one embodiment, the maximum field of view FOVW when the zoom lens group is in a wide-angle state may satisfy: 20°<FOVW<26°.

[0015] In one embodiment, at least one of the third lens and the fourth lens is a lens made of plastic, and at least one of the object side surface of the third lens, the image side surface of the third lens, the object side surface of the fourth lens, and the image side surface of the fourth lens is an aspherical mirror surface.

[0016] In one embodiment, lenses in at least one of the first lens group and the third lens group are all made of glass.

[0017] The present application provides a zoom lens group with continuous zoom, miniaturization, high integration and good imaging quality by reasonably allocating optical focal length and optimizing optical parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0019] Figure 1 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 1 of the present application is shown;

[0020] Figure 2 A schematic structural diagram showing an intermediate state of the zoom lens assembly in the process of switching from a telephoto state to a wide-angle state according to Embodiment 1 of the present application;

[0021] Figure 3 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 1 of the present application is shown;

[0022] FIG. 4A to FIG. 4D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the zoom lens group of Example 1 when it is in the telephoto state are respectively shown;

[0023] FIG. 5A to FIG. 5D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the chromatic aberration curve of magnification of the zoom lens group of Example 1 in the intermediate state during the process of switching from the telephoto state to the wide-angle state are respectively shown;

[0024] FIG. 6A to FIG. 6D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the zoom lens group of Example 1 when it is in a wide-angle state are respectively shown;

[0025] Figure 7 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 2 of the present application is shown;

[0026] Figure 8 A schematic structural diagram showing an intermediate state of a zoom lens assembly in a process of switching from a telephoto state to a wide-angle state according to Embodiment 2 of the present application;

[0027] Fig. 9 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 2 of the present application is shown;

[0028] FIG. 10A to FIG. 10D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the zoom lens group of Example 2 when it is in the telephoto state are respectively shown;

[0029] FIG. 11A to FIG. 11D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the chromatic aberration curve of magnification of the zoom lens group of Example 2 in the intermediate state during the process of switching from the telephoto state to the wide-angle state are respectively shown;

[0030] FIG. 12A to FIG. 12D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the zoom lens group of Example 2 are respectively shown when the zoom lens group is in a wide-angle state;

[0031] Fig.13 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 3 of the present application is shown;

[0032] Fig.14 A schematic structural diagram showing an intermediate state of a zoom lens assembly in a process of switching from a telephoto state to a wide-angle state according to Embodiment 3 of the present application;

[0033] Fig.15 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 3 of the present application is shown;

[0034] FIG. 16A to FIG. 16D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the zoom lens group of Example 3 when in the telephoto state are respectively shown;

[0035] FIG. 17A to FIG. 17D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the chromatic aberration curve of magnification of the zoom lens group of Example 3 in the process of switching from the telephoto state to the wide-angle state are respectively shown; and

[0036] 18A to 18D The axial chromatic aberration curve, astigmatism curve, distortion curve and lateral chromatic aberration curve of the zoom lens group of Example 3 when in a wide-angle state are respectively shown. DETAILED DESCRIPTION

[0037] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0038] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens, and the first lens group may also be referred to as the second lens group or the third lens group.

[0039] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0040] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface is not defined, 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 defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

[0041] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0042] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0043] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0044] The features, principles and other aspects of the present application are described in detail below.

[0045] The zoom lens group according to the exemplary embodiment of the present application may include four lens groups with optical power, namely, a first lens group, a second lens group, a third lens group, and a fourth lens group. By changing the spacing distance between the first lens group and the second lens group on the optical axis, the spacing distance between the second lens group and the third lens group on the optical axis, and the spacing distance between the third lens group and the fourth lens group on the optical axis, the switching of the zoom lens group from a telephoto state to a wide-angle state can be achieved.

[0046] According to an exemplary embodiment of the present application, the first lens group may have negative power, and may include a first lens and a second lens, wherein the first lens may have positive power, and its object side surface may be convex, and its image side surface may be concave; the second lens group may have positive power, and may include a third lens and a fourth lens; the third lens group may have positive power or negative power, and may include a fifth lens and a sixth lens, wherein the fifth lens and the sixth lens may be cemented to form a cemented lens; the fourth lens group may have positive power or negative power, and may include a seventh lens. These seven lenses are arranged in sequence from the object side to the image side along the optical axis.

[0047] By reasonably allocating the focal power between each lens group and the focal power of each lens in each lens group, the distance between the lens groups is controlled, so that when the entire system is working and switches from the telephoto state to the wide-angle state, the above four lens groups can achieve a continuous zoom function by changing the spacing distance between adjacent lens groups. The specific zoom process can be achieved in the following manner: by reasonably allocating the focal power of the system, when the system is in the wide-angle state, the distance between the zoom group composed of the first lens group and the second lens group is the largest, and the distance between the compensation group composed of the second lens group and the third lens group is the smallest, so that the system achieves the purpose of minimum focal length and maximum field of view. When the system switches from the wide-angle state to the telephoto state, the distance between the zoom group composed of the first lens group and the second lens group is shortened, and the distance between the compensation group composed of the second lens group and the third lens group is lengthened. The ratio of the total effective focal length of the zoom lens group in the telephoto state to the total effective focal length of the zoom lens group in the wide-angle state can be continuously changed to complete the continuous zoom process of the zoom lens group.

[0048] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 1.9<FT / FW<2.9, wherein FT is the total effective focal length of the zoom lens group when it is in a telephoto state, and FW is the total effective focal length of the zoom lens group when it is in a wide-angle state. More specifically, FT and FW may further satisfy: 1.9<FT / FW<2.8. Satisfying 1.9<FT / FW<2.9, under the condition of controlling the image plane size of the zoom lens group in the telephoto state and the wide-angle state, the range of continuous zoom can be effectively controlled, so that the lens system has a continuous zoom function within a certain range.

[0049] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: -2.9<F1 / F2<-1.6, where F1 is the effective focal length of the first lens group, and F2 is the effective focal length of the second lens group. Satisfying -2.9<F1 / F2<-1.6 can reasonably allocate the optical power of the entire system, ensuring that the system has a continuous zoom function within a certain range.

[0050] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 29mm<FT<36mm, where FT is the total effective focal length of the zoom lens group when it is in a telephoto state. Satisfying 29mm<FT<36mm can enable the system to have a larger effective focal length in the telephoto state, thereby facilitating the entire system to have a continuous zoom function within a larger range.

[0051] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 1.0<(R1+R2) / FW<1.5, wherein R1 is the radius of curvature of the object side surface of the first lens, R2 is the radius of curvature of the image side surface of the first lens, and FW is the total effective focal length of the zoom lens group when it is in a wide-angle state. More specifically, R1, R2, and FW may further satisfy: 1.1<(R1+R2) / FW<1.4. By satisfying 1.0<(R1+R2) / FW<1.5, the optical power of each lens in the first lens group can be reasonably allocated, so that the total effective focal length in the wide-angle state is within a smaller range, which can effectively ensure that the system has a larger continuous zoom range.

[0052] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 0.8<(f11+f12) / f31<1.3, wherein f11 is the effective focal length of the first lens, f12 is the effective focal length of the second lens, and f31 is the effective focal length of the fifth lens. More specifically, f11, f12, and f31 may further satisfy: 0.9<(f11+f12) / f31<1.3. Satisfying 0.8<(f11+f12) / f31<1.3 can effectively allocate the optical power of the first lens, the second lens, and the third lens, and can enable the system to have a higher image quality while ensuring the key parameters of the system.

[0053] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 0.8<f21 / R5<1.3, where f21 is the effective focal length of the third lens, and R5 is the radius of curvature of the object side surface of the third lens. Satisfying 0.8<f21 / R5<1.3 can make the object side surface and image side surface of the third lens, which is a member of the second lens group that bears the main optical power, bear reasonable optical power, so that the third lens can reduce its sensitivity as much as possible while satisfying the optical performance.

[0054] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 1.0<CT1 / CT7<2.8, wherein CT1 is the center thickness of the first lens on the optical axis, and CT7 is the center thickness of the seventh lens on the optical axis. Satisfying 1.0<CT1 / CT7<2.8 can control the distortion contribution of the first lens and the seventh lens within a reasonable range, so that the distortion amount of each field of view of the zoom lens group is within a reasonable required range, which is conducive to meeting the requirements of later software debugging.

[0055] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 0.5<R13 / R14<1.0, wherein R13 is the radius of curvature of the object side surface of the seventh lens, and R14 is the radius of curvature of the image side surface of the seventh lens. More specifically, R13 and R14 may further satisfy: 0.7<R13 / R14<1.0. Satisfying 0.5<R13 / R14<1.0 can effectively control the coma contribution rate of the seventh lens to the entire system within a reasonable range, thereby well balancing the coma generated by the front lens and obtaining good imaging quality.

[0056] In an exemplary embodiment, the zoom lens assembly according to the present application may satisfy: 20°<FOVW<26°, where FOVW is the maximum field of view angle when the zoom lens assembly is in a wide-angle state. Satisfying 20°<FOVW<26° is conducive to maximizing the effective focal length of the zoom lens assembly, thereby ensuring that the entire system has a large continuous zoom range.

[0057] In an exemplary embodiment, at least one of the third lens and the fourth lens is a lens made of plastic material, and at least one of the object side surface of the third lens, the image side surface of the third lens, the object side surface of the fourth lens, and the image side surface of the fourth lens is an aspherical mirror surface. At least one lens in the second lens group is a lens made of plastic material, which is conducive to ensuring that the weight of the entire system is not too heavy. At least one lens in the second lens group has at least one aspherical mirror surface, which is conducive to ensuring that the system has more optimization freedom, thereby facilitating ensuring that the system has a higher resolution.

[0058] In an exemplary embodiment, the lenses in at least one of the first lens group and the third lens group are all made of glass. Since glass has a wide refractive index distribution range and a small expansion coefficient, the lenses in at least one of the first lens group and the third lens group of the entire system are all made of glass, which is conducive to ensuring that the system has good imaging quality and is also conducive to controlling the temperature drift effect of the entire system.

[0059] In an exemplary embodiment, the zoom lens group according to the present application further includes an aperture provided between the first lens group and the second lens group. Optionally, the zoom lens group may further include a filter for correcting color deviation and / or a protective glass for protecting a photosensitive element located on the imaging surface.

[0060] The present application proposes a zoom lens group with the characteristics of continuous zoom, high integration, miniaturization, high imaging quality, etc. The zoom lens group according to the above-mentioned embodiment of the present application can use multiple lenses, such as the seven lenses mentioned above. By reasonably allocating the focal length, surface shape, center thickness of each lens, and axial spacing between each lens, etc., the incident light can be effectively converged, the total optical length of the imaging lens can be reduced, and the processability of the imaging lens can be improved, making the zoom lens group more conducive to production and processing.

[0061] In the embodiment of the present application, at least one of the mirror surfaces of each lens is an aspherical mirror surface, that is, at least one of the mirror surfaces from the object side of the first lens to the image side of the seventh lens is an aspherical mirror surface. The characteristic of the aspherical lens is that the curvature changes continuously from the center of the lens to the periphery of the lens. Unlike a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. After adopting an aspherical lens, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality. Optionally, at least one of the object side and image side of each lens in the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens is an aspherical mirror surface. Optionally, the object side and image side of each lens in the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all aspherical mirror surfaces.

[0062] However, it should be understood by those skilled in the art that, without departing from the technical solution claimed in the present application, the number of lenses constituting the zoom lens group can be changed to obtain the various results and advantages described in this specification. For example, although seven lenses are described as an example in the embodiments, the zoom lens group is not limited to including seven lenses. If necessary, the zoom lens group may also include other numbers of lenses.

[0063] Specific embodiments of the zoom lens group applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0064] Example 1

[0065] The following reference Figures 1 to 6D A zoom lens group according to Example 1 of the present application is described. Figure 1 A schematic structural diagram of the zoom lens group in telephoto state according to Embodiment 1 of the present application is shown. Figure 2 A schematic structural diagram of an intermediate state of a zoom lens group in a process of switching from a telephoto state to a wide-angle state according to Example 1 of the present application is shown. Figure 3 A schematic diagram of the structure of the zoom lens group according to Example 1 of the present application when in a wide-angle state is shown.

[0066] like Figure 1-Figure 3 As shown, the zoom lens group includes, from the object side to the image side, a first lens group G1 (a first lens E1 and a second lens E2), a second lens group G2 (a third lens E3 and a fourth lens E4), a third lens group G3 (a fifth lens E5 and a sixth lens E6), a fourth lens group G4 (a seventh lens E7), a filter E8 and an imaging surface S17.

[0067] The object side surface S1 of the first lens E1 is convex, and the image side surface S2 is concave. The object side surface S3 of the second lens E2 is concave, and the image side surface S4 is concave. The object side surface S5 of the third lens E3 is convex, and the image side surface S6 is convex. The object side surface S7 of the fourth lens E4 is convex, and the image side surface S8 is concave. The object side surface S9 of the fifth lens E5 is convex, and the image side surface S10 is convex. The object side surface S11 of the sixth lens E6 is concave, and the image side surface S12 is convex. The object side surface S13 of the seventh lens E7 is concave, and the image side surface S14 is convex. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0068] Table 1 shows the basic parameters of the zoom lens assembly of Example 1, wherein the units of the curvature radius and thickness / distance are both millimeters (mm).

[0069] Face number Surface type Radius of curvature Thickness / distance Refractive Index Abbe number Material Cone coefficient OBJ Spherical endless endless S1 Spherical 8.5227 3.2648 1.91 31.4 Glass S2 Spherical 8.5572 0.8066 S3 Spherical -18.1410 0.4200 1.65 58.4 Glass S4 Spherical 14.4384 D4 S5(STO) Spherical 6.9142 1.0224 1.74 52.7 Glass S6 Spherical -29.1766 0.0300 S7 Aspheric 22.9486 0.5500 1.67 20.4 plastic 0.0000 S8 Aspheric 7.0216 D8 0.0000 S9 Spherical 27.0482 0.6036 1.50 81.6 Glass S10 Spherical -57.3354 0.0000 S11 Spherical -57.3354 1.3721 1.93 20.9 Glass S12 Spherical -41.9373 D12 S13 Spherical -6.1084 1.2323 1.93 20.9 Glass S14 Spherical -6.6345 14.5000 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.2900 S17 Spherical endless

[0070] Table 1

[0071] In this example, the zoom lens group is switched from the telephoto state to the wide-angle state or from the wide-angle state to the telephoto state by changing the spacing distance D4 between the first lens group and the second lens group on the optical axis (i.e., the spacing distance on the optical axis from the image side surface of the second lens E2 to the object side surface of the third lens E3), the spacing distance D8 between the second lens group and the third lens group on the optical axis (i.e., the spacing distance on the optical axis from the image side surface of the fourth lens E4 to the object side surface of the fifth lens E5), and the spacing distance D12 between the third lens group and the fourth lens group on the optical axis (i.e., the spacing distance on the optical axis from the image side surface of the sixth lens E6 to the object side surface of the seventh lens E7). The total effective focal length f of the zoom lens group, the aperture value Fno, the maximum field of view FOV, the total length TTL of the zoom lens group (i.e., the distance on the optical axis from the object side surface S1 of the first lens E1 to the imaging surface S17 of the zoom lens group) and half the diagonal length ImgH of the effective pixel area on the imaging surface S17 of the zoom lens group change as the zoom lens group switches from the telephoto state to the wide-angle state or from the wide-angle state to the telephoto state.

[0072] Table 2 shows various parameters of the zoom lens group in different states of Example 1, wherein the units of f, TTL, ImgH, D4, D8 and D12 are all millimeters (mm), and the unit of FOV is degrees (°).

[0073] Parameters Telephoto state Intermediate state Wide angle state f 29.94 21.96 15.18 Fno 4.39 3.76 3.12 FOV 10.4 14.2 20.9 TTL 32.80 32.80 32.80 Ih 2.72 2.72 2.72 D4 0.03 3.10 7.48 D8 2.14 2.81 0.48 D12 6.33 2.59 0.54

[0074] Table 2

[0075] In Example 1, both the object-side surface S7 and the image-side surface S8 of the fourth lens E4 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0076]

[0077] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 3 below gives the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, 10 and A 12 .

[0078] Face number A4 A6 A8 A10 A12 S7 5.5482E-04 -6.7063E-05 1.9924E-06 -2.8679E-08 2.1129E-10 S8 1.4492E-03 -5.2293E-05 3.6304E-06 -1.0936E-07 1.7587E-09

[0079] Table 3

[0080] Figure 4A , Figure 5A , Fig. 6AThe axial chromatic aberration curves of the zoom lens group of Example 1 when in the telephoto state, the intermediate state and the wide-angle state are respectively shown, which indicate that light rays of different wavelengths deviate from the focal point behind the lens. Figure 4B , Figure 5B , Figure 6B The astigmatism curves of the zoom lens group of Example 1 when in the telephoto state, the intermediate state and the wide-angle state are respectively shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 4C , Figure 5C , Figure 6C The distortion curves of the zoom lens group of Example 1 when they are in a telephoto state, a middle state and a wide-angle state are shown respectively, which represent the distortion magnitude values ​​corresponding to different image heights. Figure 4D , Figure 5D , Fig.6D The magnification chromatic aberration curves of the zoom lens group of Example 1 are respectively shown when they are in the telephoto state, the intermediate state and the wide-angle state, which represent the deviations of different image heights on the imaging surface after the light passes through the lens. 4A to 6D It can be seen that the zoom lens group provided in Example 1 can achieve good imaging quality in all states.

[0081] Example 2

[0082] The following reference Figures 7 to 12D A zoom lens assembly according to Embodiment 2 of the present application is described. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to Embodiment 1 will be omitted. Figure 7 A schematic diagram of the structure of the zoom lens group according to Embodiment 2 of the present application when in a telephoto state is shown. Figure 8 A schematic structural diagram of an intermediate state of a zoom lens group in the process of switching from a telephoto state to a wide-angle state according to Embodiment 2 of the present application is shown. Fig. 9 A schematic structural diagram of the zoom lens group according to Example 2 of the present application when in a wide-angle state is shown.

[0083] like Figure 7-Figure 9 As shown, the zoom lens group includes, from the object side to the image side, a first lens group G1 (a first lens E1 and a second lens E2), a second lens group G2 (a third lens E3 and a fourth lens E4), a third lens group G3 (a fifth lens E5 and a sixth lens E6), a fourth lens group G4 (a seventh lens E7), a filter E8 and an imaging surface S17.

[0084] The object side surface S1 of the first lens E1 is convex, and the image side surface S2 is concave. The object side surface S3 of the second lens E2 is concave, and the image side surface S4 is concave. The object side surface S5 of the third lens E3 is convex, and the image side surface S6 is convex. The object side surface S7 of the fourth lens E4 is concave, and the image side surface S8 is concave. The object side surface S9 of the fifth lens E5 is convex, and the image side surface S10 is concave. The object side surface S11 of the sixth lens E6 is convex, and the image side surface S12 is concave. The object side surface S13 of the seventh lens E7 is concave, and the image side surface S14 is convex. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0085] Table 4 shows the basic parameter table of the zoom lens group of Example 2, wherein the units of the curvature radius and thickness / distance are both millimeters (mm).

[0086]

[0087]

[0088] Table 4

[0089] In this example, the zoom lens group is switched from the telephoto state to the wide-angle state or from the wide-angle state to the telephoto state by changing the spacing distance D4 between the first lens group and the second lens group on the optical axis, the spacing distance D8 between the second lens group and the third lens group on the optical axis, and the spacing distance D12 between the third lens group and the fourth lens group on the optical axis. The total effective focal length f of the zoom lens group, the aperture value Fno, the maximum field of view FOV, the total length TTL of the zoom lens group, and the half of the diagonal length ImgH of the effective pixel area on the imaging surface S17 of the zoom lens group change as the zoom lens group switches from the telephoto state to the wide-angle state or from the wide-angle state to the telephoto state.

[0090] Table 5 shows various parameters of Example 2 under different states of the zoom lens group, wherein the units of f, TTL, ImgH, D4, D8 and D12 are all millimeters (mm), and the unit of FOV is degrees (°).

[0091] Parameters Telephoto state Intermediate state Wide angle state f 30.06 19.97 15.11 Fno 4.29 3.36 3.10 FOV 10.4 15.6 21.1 TTL 35.00 30.08 34.48 Ih 2.72 2.72 2.72 D4 0.03 2.99 7.27 D8 6.38 0.09 2.59 D12 4.63 3.05 0.66

[0092] Table 5

[0093] Table 6 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 2, wherein each aspherical surface shape can be defined by the formula (1) given in the above-mentioned Example 1.

[0094] Face number A4 A6 A8 A10 A12 S7 3.6903E-04 -3.9860E-05 9.6922E-07 -1.1518E-08 7.1653E-11 S8 9.7424E-04 -3.0938E-05 1.5355E-06 -4.0302E-08 4.8859E-10

[0095] Table 6

[0096] Fig. 10A , 11A 12A and 12B respectively show the axial chromatic aberration curves when the zoom lens group of Example 2 is in the telephoto state, the intermediate state and the wide-angle state, which indicate that light rays of different wavelengths deviate from the focal point behind the lens. Fig. 10B , 11B 12A and 12B respectively show the astigmatism curves of the zoom lens group of Example 2 when it is in the telephoto state, the intermediate state and the wide-angle state, which represent the meridional image curvature and the sagittal image curvature. Fig. 10C , 11C 12C respectively show the distortion curves of the zoom lens group of Example 2 when it is in the telephoto state, the intermediate state and the wide-angle state, which represent the distortion magnitude values ​​corresponding to different image heights. Fig. 10D , 11D 12D respectively show the magnification chromatic aberration curves when the zoom lens group of Example 2 is in the telephoto state, the intermediate state and the wide-angle state, which represent the deviation of different image heights on the imaging surface after the light passes through the lens. FIG. 10A to FIG. 12D It can be seen that the zoom lens group provided in Example 2 can achieve good imaging quality in all states.

[0097] Example 3

[0098] The following reference Figures 13 to 18D A zoom lens group according to Example 3 of the present application is described. Fig.13 A schematic diagram of the structure of the zoom lens group according to Example 3 of the present application when in a telephoto state is shown. Fig.14 A schematic structural diagram of an intermediate state of a zoom lens group in the process of switching from a telephoto state to a wide-angle state according to Example 3 of the present application is shown. Fig.15 A schematic structural diagram of the zoom lens group in a wide-angle state according to Example 3 of the present application is shown.

[0099] like Figure 13-Figure 15 As shown, the zoom lens group includes, from the object side to the image side, a first lens group G1 (a first lens E1 and a second lens E2), a second lens group G2 (a third lens E3 and a fourth lens E4), a third lens group G3 (a fifth lens E5 and a sixth lens E6), a fourth lens group G4 (a seventh lens E7), a filter E8 and an imaging surface S17.

[0100] The object side surface S1 of the first lens E1 is convex, and the image side surface S2 is concave. The object side surface S3 of the second lens E2 is concave, and the image side surface S4 is concave. The object side surface S5 of the third lens E3 is convex, and the image side surface S6 is convex. The object side surface S7 of the fourth lens E4 is convex, and the image side surface S8 is concave. The object side surface S9 of the fifth lens E5 is convex, and the image side surface S10 is concave. The object side surface S11 of the sixth lens E6 is convex, and the image side surface S12 is concave. The object side surface S13 of the seventh lens E7 is convex, and the image side surface S14 is concave. The filter E8 has an object side surface S15 and an image side surface S16. The light from the object passes through each surface S1 to S16 in sequence and is finally imaged on the imaging surface S17.

[0101] Table 7 shows the basic parameter table of the zoom lens group of Example 3, wherein the units of the curvature radius and thickness / distance are both millimeters (mm).

[0102] Face number Surface type Radius of curvature Thickness / distance Refractive Index Abbe number Material Cone coefficient OBJ Spherical endless endless S1 Spherical 8.2831 3.3927 1.91 31.4 Glass S2 Spherical 8.7411 1.0372 S3 Spherical -180.7267 0.2500 1.65 58.4 Glass S4 Spherical 8.6366 D4 S5(STO) Spherical 8.5320 1.0160 1.74 52.7 Glass S6 Spherical -66.0563 0.0300 S7 Aspheric 22.6594 0.5000 1.67 20.4 plastic 0.0000 S8 Aspheric 24.3013 D8 0.0000 S9 Spherical 8.1849 0.7322 1.50 81.6 Glass S10 Spherical 33.6591 0.0000 S11 Spherical 33.6591 1.1795 1.93 20.9 Glass S12 Spherical 7.8610 D12 S13 Spherical 7.3827 1.2294 1.93 20.9 Glass S14 Spherical 8.1383 7.5282 S15 Spherical endless 0.2100 1.52 64.2 S16 Spherical endless 0.2900 S17 Spherical endless

[0103] Table 7

[0104] In this example, the zoom lens group is switched from the telephoto state to the wide-angle state or from the wide-angle state to the telephoto state by changing the spacing distance D4 between the first lens group and the second lens group on the optical axis, the spacing distance D8 between the second lens group and the third lens group on the optical axis, and the spacing distance D12 between the third lens group and the fourth lens group on the optical axis. The total effective focal length f of the zoom lens group, the aperture value Fno, the maximum field of view FOV, the total length TTL of the zoom lens group, and the half of the diagonal length ImgH of the effective pixel area on the imaging surface S17 of the zoom lens group change as the zoom lens group switches from the telephoto state to the wide-angle state or from the wide-angle state to the telephoto state.

[0105] Table 8 shows the parameters of Example 3 under different states of the zoom lens group, wherein the units of f, TTL, ImgH, D4, D8 and D12 are all millimeters (mm), and the unit of FOV is degrees (°).

[0106] Parameters Telephoto state Intermediate state Wide angle state f 35.33 20.00 12.89 Fno 4.19 3.01 2.45 FOV 8.9 15.8 25.0 TTL 35.00 31.68 35.00 Ih 2.72 2.72 2.72 D4 0.03 5.74 13.11 D8 0.02 0.07 0.00 D12 17.55 8.48 4.50

[0107] Table 8

[0108] Table 9 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A62, A63, A70, A71, A72, A73, A 10 , A 12 , A 14 , A 16 , A 18 and A 20 Wherein, each aspheric surface shape can be defined by the formula (1) given in the above embodiment 1.

[0109] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S7 4.9893E-05 -4.5445E-05 3.8446E-05 -1.1930E-05 2.2894E-06 -2.7422E-07 1.9950E-08 -8.0674E-10 1.3912E-11 S8 4.0672E-04 -4.6538E-05 4.5668E-05 -1.4694E-05 2.9260E-06 -3.6195E-07 2.7067E-08 -1.1185E-09 1.9572E-11

[0110] Table 9

[0111] Fig.16A , 17A 18A respectively show the axial chromatic aberration curves when the zoom lens group of Example 3 is in the telephoto state, the intermediate state and the wide-angle state, which indicate that light rays of different wavelengths deviate from the focal point behind the lens. Fig. 16B , 17B 18B and 18B respectively show the astigmatism curves of the zoom lens group of Example 3 when it is in the telephoto state, the intermediate state and the wide-angle state, which represent the meridional image curvature and the sagittal image curvature. Fig. 16C , 17C 18C respectively show the distortion curves of the zoom lens group of Example 3 when it is in the telephoto state, the intermediate state and the wide-angle state, which represent the distortion magnitude values ​​corresponding to different image heights. Fig.16D , 17D 18D respectively show the magnification chromatic aberration curves when the zoom lens group of Example 3 is in the telephoto state, the intermediate state and the wide-angle state, which represent the deviation of different image heights on the imaging surface after the light passes through the lens. FIG. 16A to FIG. 18D It can be seen that the zoom lens group provided in Example 3 can achieve good imaging quality in all states.

[0112] In summary, Examples 1 to 3 respectively satisfy the relationships shown in Table 10.

[0113]

[0114]

[0115] Table 10

[0116] The present application also provides an imaging device, whose electronic photosensitive element can be a photosensitive coupled device (CCD) or a complementary metal oxide semiconductor element (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated in a mobile electronic device such as a mobile phone. The imaging device is equipped with the zoom lens group described above.

[0117] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A zoom lens assembly, characterized in that: Along the optical axis from the object side to the image side, they include: A first lens group with negative optical power, comprising a first lens and a second lens, wherein the first lens has positive optical power, its object side surface is convex, and its image side surface is concave; the second lens has negative optical power, its object side surface is concave, and its image side surface is concave; A second lens group with positive refractive power comprises a third lens and a fourth lens, wherein the third lens has positive refractive power, an object side surface thereof is convex, and an image side surface thereof is convex; and the image side surface of the fourth lens is concave; a third lens group having optical power, comprising a fifth lens and a sixth lens, wherein the fifth lens and the sixth lens form a cemented lens; the fifth lens has positive optical power, and its object side surface is a convex surface; and a fourth lens group having optical power, comprising a seventh lens; Wherein, the number of lenses having optical power in the zoom lens group is seven; The third lens group and the fourth lens group have the same positive power or opposite power; The third lens group and the fourth lens group have the same positive refractive power, the image side surface of the sixth lens is convex, the object side surface of the seventh lens is concave, and the image side surface is convex; Or the optical power of the third lens group is positive, the optical power of the fourth lens group is negative, the image side surface of the sixth lens is concave, the object side surface of the seventh lens is concave, and the image side surface is convex; Or the optical power of the third lens group is negative, the optical power of the fourth lens group is positive, the image side surface of the sixth lens is concave, the object side surface of the seventh lens is convex, and the image side surface is concave; Change the spacing distance between the first lens group and the second lens group on the optical axis, the spacing distance between the second lens group and the third lens group on the optical axis, and the spacing distance between the third lens group and the fourth lens group on the optical axis to achieve switching of the zoom lens group from a telephoto state to a wide-angle state.

2. The zoom lens assembly according to claim 1, characterized in that: The total effective focal length FT of the zoom lens group when it is in a telephoto state and the total effective focal length FW of the zoom lens group when it is in a wide-angle state satisfy: 1.97≤FT / FW≤2.

74.

3. The zoom lens assembly according to claim 1, characterized in that: The effective focal length F1 of the first lens group and the effective focal length F2 of the second lens group satisfy: -2.85≤F1 / F2≤-1.

65.

4. The zoom lens assembly according to claim 1, wherein: The total effective focal length FT of the zoom lens group when in a telephoto state satisfies: 29.94 mm≤FT≤35.33 mm.

5. The zoom lens assembly according to claim 1, characterized in that: The curvature radius R1 of the object side surface of the first lens, the curvature radius R2 of the image side surface of the first lens, and the total effective focal length FW of the zoom lens group in a wide-angle state satisfy: 1.1<(R1+R2) / FW≤1.

32.

6. The zoom lens assembly according to claim 1, characterized in that: The effective focal length f11 of the first lens, the effective focal length f12 of the second lens, and the effective focal length f31 of the fifth lens satisfy: 0.98≤(f11+f12) / f31≤1.

20.

7. The zoom lens assembly according to claim 1, characterized in that: An effective focal length f21 of the third lens and a curvature radius R5 of the object side surface of the third lens satisfy: 0.90≤f21 / R5≤1.

20.

8. The zoom lens assembly according to claim 1, wherein: A center thickness CT1 of the first lens on the optical axis and a center thickness CT7 of the seventh lens on the optical axis satisfy: 1.08≤CT1 / CT7<2.

8.

9. The zoom lens assembly according to claim 1, wherein: A curvature radius R13 of the object-side surface of the seventh lens and a curvature radius R14 of the image-side surface of the seventh lens satisfy: 0.75≤R13 / R14≤0.

92.

10. The zoom lens assembly according to claim 1, wherein: The maximum field of view angle FOVW of the zoom lens group when in a wide-angle state satisfies: 20.9°≤FOVW≤25°.

11. The zoom lens assembly according to claim 1, wherein: At least one of the third lens and the fourth lens is a lens made of plastic material, and at least one of the object side surface of the third lens, the image side surface of the third lens, the object side surface of the fourth lens, and the image side surface of the fourth lens is an aspherical mirror surface.

12. The zoom lens assembly according to claim 1, wherein: The lenses in at least one of the first lens group and the third lens group are all made of glass.

Images