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 negative optical power and its object side surface is a concave surface; a second lens group with positive optical power, which includes a third lens and a fourth lens; a third lens group with positive 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 negative 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 the purpose of "continuous" zoom in the true optical sense of a single zoom lens group by reasonably allocating the optical focal length of the zoom lens group and optimizing the optical parameters, while meeting the requirements of processability and miniaturization of the zoom lens group 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 may include a first lens and a second lens, wherein the first lens may have negative optical power and its object side surface may be a concave surface; a second lens group with positive optical power, which may include a third lens and a fourth lens; a third lens group with positive optical power, which may include a fifth lens and a sixth lens, wherein the fifth lens and the sixth lens are cemented to form a cemented lens; and a fourth lens group with negative optical power, which may include 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 effective focal length F1 of the first lens group and the effective focal length F4 of the fourth lens group may satisfy: 0.5<F1 / F4<0.9.

[0007] In one embodiment, the effective focal length F2 of the second lens group and the effective focal length F3 of the third lens group may satisfy: 0.5<F2 / F3<1.0.

[0008] 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<3.

[0009] In one embodiment, the total effective focal length FT of the zoom lens group when it is in the telephoto state, the total effective focal length FM of the zoom lens group when it is in an intermediate state in the process of switching from the telephoto state to the wide-angle state, the total effective focal length FW of the zoom lens group when it is in the wide-angle state, and the effective focal length f11 of the first lens may satisfy: -1.3<(FT+FM+FW) / f11<-0.2.

[0010] In one embodiment, the effective focal length f31 of the fifth lens, the effective focal length f32 of the sixth lens, the effective focal length f21 of the third lens, and the effective focal length f22 of the fourth lens may satisfy: 0.6<(f31-f32) / (f21-f22)<1.0.

[0011] In one embodiment, the maximum field of view angle FOVT when the zoom lens group is in a telephoto state may satisfy: 10°<FOVT<15°.

[0012] In one embodiment, a curvature radius R7 of the object-side surface of the fourth lens and a curvature radius R8 of the image-side surface of the fourth lens may satisfy: 0.3<(R7-R8) / (R7+R8)<0.5.

[0013] In one embodiment, a center thickness CT3 of the third lens on the optical axis, a center thickness CT4 of the fourth lens on the optical axis, and a center thickness CT1 of the first lens on the optical axis may satisfy: 0.4<(CT3+CT4) / CT1<0.6.

[0014] In one embodiment, the center thickness CT1 of the first lens on the optical axis and the spacing distance T12 between the first lens and the second lens on the optical axis may satisfy: 9.0 mm<CT1+T12<11.0 mm.

[0015] In one embodiment, the effective focal length f12 of the second lens and the curvature radius R1 of the object-side surface of the first lens may satisfy: 0.1<f12 / R1<1.5.

[0016] The present application provides a zoom lens group with continuous zoom, miniaturization, processability and good imaging quality by reasonably allocating optical focal length and optimizing optical parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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:

[0018] 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;

[0019] 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;

[0020] 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;

[0021] 4A to 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;

[0022] 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;

[0023] 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;

[0024] 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;

[0025] 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;

[0026] 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;

[0027] 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;

[0028] 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;

[0029] 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;

[0030] 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;

[0031] 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;

[0032] 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;

[0033] 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;

[0034] 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 intermediate state during the process of switching from the telephoto state to the wide-angle state are respectively shown;

[0035] 18A to 18D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the zoom lens group of Example 3 when in a wide-angle state are respectively shown;

[0036] Fig.19 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 4 of the present application is shown;

[0037] Fig. 20 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 4 of the present application;

[0038] Fig.21 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 4 of the present application is shown;

[0039] FIG. 22A to FIG. 22D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the magnification chromatic aberration curve of the zoom lens group of Example 4 when it is in the telephoto state are respectively shown;

[0040] FIG. 23A to FIG. 23D 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 4 in the process of switching from the telephoto state to the wide-angle state are respectively shown; and

[0041] FIG. 24A to FIG. 24D The axial chromatic aberration curve, astigmatism curve, distortion curve and lateral chromatic aberration curve of the zoom lens group of Example 4 when in a wide-angle state are respectively shown. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The features, principles and other aspects of the present application are described in detail below.

[0050] 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.

[0051] 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 negative power, and its object side surface may be a concave surface; 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, 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 negative power, and may include a seventh lens. The four lens groups are arranged in sequence from the object side to the image side along the optical axis. The seven lenses are arranged in sequence from the object side to the image side along the optical axis.

[0052] By properly adjusting the focal length of the zoom lens group as a whole, the zoom lens group can have the characteristic of continuous zoom. By controlling the aperture of the first lens and the second lens, the system can have the characteristic of small size. By controlling the third lens and the fourth lens to be a combination of positive and negative focal lengths, the system aberration can be optimized. By controlling the fifth lens and the sixth lens to form a cemented lens, the effect of optimizing chromatic aberration can be achieved. By reasonably allocating the focal length between each lens group and the focal length of each lens in each lens group, the distance between the lens groups can be controlled, so that when the entire system is working, when switching from a telephoto state to a 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 system focal length, when the system is in a wide-angle state, the distance between the zoom groups formed by the first lens group and the second lens group is the largest, and the distance between the compensation groups formed by the second lens group, the third lens group and the fourth 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 groups formed by the first lens group and the second lens group is shortened, and the distance between the compensation groups formed by the second lens group, the third lens group and the fourth 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. The first lens can be a prism, which is used to fold the light path to achieve the effect of periscope continuous zoom.

[0053] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 0.5<F1 / F4<0.9, where F1 is the effective focal length of the first lens group, and F4 is the effective focal length of the fourth lens group. When 0.5<F1 / F4<0.9 is satisfied, the contribution range of the optical power of the first lens group and the fourth lens group can be reasonably controlled, and the spherical aberration contribution rate of the first lens group and the fourth lens group can be reasonably controlled.

[0054] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 0.5<F2 / F3<1.0, where F2 is the effective focal length of the second lens group, and F3 is the effective focal length of the third lens group. More specifically, F2 and F3 may further satisfy: 0.5<F2 / F3<0.9. Satisfying 0.5<F2 / F3<1.0 can control the contribution of the aberrations of the two lens groups, which is beneficial to balance the aberrations generated by the rear optical lens, so that the system aberrations are within a reasonable range, and thus it is beneficial to make the optical imaging system have good imaging quality.

[0055] In an exemplary embodiment, the zoom lens assembly according to the present application may satisfy: 1.9<FT / FW<3, where FT is the total effective focal length of the zoom lens assembly when it is in a telephoto state, and FW is the total effective focal length of the zoom lens assembly when it is in a wide-angle state. Satisfying 1.9<FT / FW<3 is conducive to realizing the continuous zoom process of the optical imaging system, so that the optical imaging system has good imaging quality.

[0056] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: -1.3<(FT+FM+FW) / f11<-0.2, wherein FT is the total effective focal length of the zoom lens group when it is in a telephoto state, FM is the total effective focal length of the zoom lens group when it is in an intermediate state in the process of switching from a telephoto state to a wide-angle state, FW is the total effective focal length of the zoom lens group when it is in a wide-angle state, and f11 is the effective focal length of the first lens. Satisfying -1.3<(FT+FM+FW) / f11<-0.2 is conducive to making the first lens group have a lens with negative optical power to balance the aberrations generated by the lens group with positive optical power at the rear end, thereby obtaining good imaging quality and achieving a high resolution effect.

[0057] In an exemplary embodiment, the zoom lens assembly according to the present application may satisfy: 0.6<(f31-f32) / (f21-f22)<1.0, wherein f31 is the effective focal length of the fifth lens, f32 is the effective focal length of the sixth lens, f21 is the effective focal length of the third lens, and f22 is the effective focal length of the fourth lens. Satisfying 0.6<(f31-f32) / (f21-f22)<1.0 can ensure that the optical system has excellent image quality and good processability.

[0058] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 10°<FOVT<15°, where FOVT is the maximum field of view angle when the zoom lens group is in a telephoto state. More specifically, FOVT may further satisfy: 10°<FOVT<12°. Satisfying 10°<FOVT<15° is conducive to achieving the telephoto characteristics of the camera lens.

[0059] In an exemplary embodiment, the zoom lens assembly according to the present application may satisfy: 0.3<(R7-R8) / (R7+R8)<0.5, where R7 is the radius of curvature of the object side surface of the fourth lens, and R8 is the radius of curvature of the image side surface of the fourth lens. Satisfying 0.3<(R7-R8) / (R7+R8)<0.5 can effectively constrain the shape of the fourth lens, and further effectively control the aberration contribution rate of the object side surface and the image side surface of the fourth lens, so as to effectively balance the aberrations of the system related to the aperture zone, and further effectively improve the imaging quality of the system.

[0060] In an exemplary embodiment, the zoom lens assembly according to the present application may satisfy: 0.4<(CT3+CT4) / CT1<0.6, wherein CT3 is the center thickness of the third lens on the optical axis, CT4 is the center thickness of the fourth lens on the optical axis, and CT1 is the center thickness of the first lens on the optical axis. Satisfying 0.4<(CT3+CT4) / CT1<0.6 can make the zoom lens assembly have good processing performance.

[0061] In an exemplary embodiment, the zoom lens assembly according to the present application may satisfy: 9.0mm<CT1+T12<11.0mm, wherein CT1 is the center thickness of the first lens on the optical axis, and T12 is the spacing distance between the first lens and the second lens on the optical axis. More specifically, CT1 and T12 may further satisfy: 10mm<CT1+T12<11.0mm. Satisfying 9.0mm<CT1+T12<11.0mm can make the zoom lens assembly have good processing performance.

[0062] In an exemplary embodiment, the zoom lens assembly according to the present application may satisfy: 0.1<f12 / R1<1.5, where f12 is the effective focal length of the second lens, and R1 is the radius of curvature of the object side of the first lens. Satisfying 0.1<f12 / R1<1.5 can effectively constrain the aberration contribution rate of the object side of the first lens, effectively balance the aberrations related to the system and the aperture zone, and thus effectively improve the imaging quality of the system.

[0063] 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.

[0064] The present application proposes a zoom lens group with the characteristics of continuous zoom, 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.

[0065] 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.

[0066] 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.

[0067] Specific embodiments of the zoom lens group applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0068] Example 1

[0069] 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 structural diagram of the zoom lens group according to Example 1 of the present application when in a wide-angle state is shown.

[0070] 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 S16.

[0071] The object side surface S1 of the first lens E1 is a concave surface, and the image side surface S2 is a convex surface. The object side surface S3 of the second lens E2 is a concave surface, and the image side surface S4 is a concave surface. The object side surface S5 of the third lens E3 is a convex surface, and the image side surface S6 is a convex surface. The object side surface S7 of the fourth lens E4 is a convex surface, and the image side surface S8 is a concave surface. The object side surface S9 of the fifth lens E5 is a convex surface, and the image side surface S10 is a convex surface. The object side surface S10 of the sixth lens E6 is a concave surface, and the image side surface S11 is a concave surface. The object side surface S12 of the seventh lens E7 is a concave surface, and the image side surface S13 is a convex surface. The filter E8 has an object side surface S14 and an image side surface S15. The light from the object passes through each surface S1 to S15 in sequence and is finally imaged on the imaging surface S16.

[0072] 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).

[0073]

[0074]

[0075] Table 1

[0076] In this example, the zoom lens group is switched from a telephoto state to a wide-angle state or from a wide-angle state to a 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 D11 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 S16 of the zoom lens group) and half the diagonal length ImgH of the effective pixel area on the imaging surface S16 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.

[0077] Table 2 shows various parameters of the zoom lens group of Example 1 in different states, wherein the units of f, TTL, ImgH, D4, D8 and D11 are all millimeters (mm), and the unit of FOV is degrees (°).

[0078] Parameters Telephoto state Intermediate state Wide angle state f 29.90 21.94 15.17 Fno 3.81 3.34 2.77 FOV 10.4 14.2 20.6 TTL 45.00 45.00 45.00 Ih 2.72 2.72 2.72 D4 0.03 4.11 9.29 D8 5.11 4.14 0.57 D11 5.08 1.96 0.35

[0079] Table 2

[0080] 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:

[0081]

[0082] 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 , A 12 , A 14 and A 16 .

[0083]

[0084]

[0085] Table 3

[0086] Figure 4A , Figure 5A , Fig. 6A The 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 in a telephoto state, an intermediate state and a wide-angle state are respectively shown, 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.

[0087] Example 2

[0088] The following reference Figures 7 to 12DA 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.

[0089] 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 S16.

[0090] The object side surface S1 of the first lens E1 is a concave surface, and the image side surface S2 is a convex surface. The object side surface S3 of the second lens E2 is a concave surface, and the image side surface S4 is a concave surface. The object side surface S5 of the third lens E3 is a convex surface, and the image side surface S6 is a convex surface. The object side surface S7 of the fourth lens E4 is a convex surface, and the image side surface S8 is a concave surface. The object side surface S9 of the fifth lens E5 is a convex surface, and the image side surface S10 is a convex surface. The object side surface S10 of the sixth lens E6 is a concave surface, and the image side surface S11 is a concave surface. The object side surface S12 of the seventh lens E7 is a concave surface, and the image side surface S13 is a convex surface. The filter E8 has an object side surface S14 and an image side surface S15. The light from the object passes through each surface S1 to S15 in sequence and is finally imaged on the imaging surface S16.

[0091] 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).

[0092]

[0093]

[0094] Table 4

[0095] 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 D11 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 S16 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.

[0096] 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 D11 are all millimeters (mm), and the unit of FOV is degrees (°).

[0097] Parameters Telephoto state Intermediate state Wide angle state f 28.02 16.37 12.25 Fno 3.81 3.34 2.77 FOV 11.1 19.1 25.7 TTL 45.00 45.00 45.00 Ih 2.72 2.72 2.72 D4 0.03 6.88 10.75 D8 5.77 3.70 0.54 D11 5.76 0.98 0.27

[0098] Table 5

[0099] 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.

[0100] Face number A4 A6 A8 A10 A12 A14 A16 S7 -2.3900E-03 6.8623E-05 -1.3503E-06 6.4360E-09 -2.7500E-10 5.5339E-12 -3.1488E-13 S8 -1.9200E-03 9.1762E-05 -3.0886E-07 -9.8462E-09 5.5977E-10 -9.2928E-12 5.1821E-13

[0101] Table 6

[0102] 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.

[0103] Example 3

[0104] 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.

[0105] 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 S16.

[0106] The object side surface S1 of the first lens E1 is a concave surface, and the image side surface S2 is a concave surface. The object side surface S3 of the second lens E2 is a concave surface, and the image side surface S4 is a concave surface. The object side surface S5 of the third lens E3 is a convex surface, and the image side surface S6 is a convex surface. The object side surface S7 of the fourth lens E4 is a convex surface, and the image side surface S8 is a concave surface. The object side surface S9 of the fifth lens E5 is a convex surface, and the image side surface S10 is a convex surface. The object side surface S10 of the sixth lens E6 is a concave surface, and the image side surface S11 is a concave surface. The object side surface S12 of the seventh lens E7 is a concave surface, and the image side surface S13 is a concave surface. The filter E8 has an object side surface S14 and an image side surface S15. The light from the object passes through each surface S1 to S15 in sequence and is finally imaged on the imaging surface S16.

[0107] 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).

[0108]

[0109]

[0110] Table 7

[0111] 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 D11 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 S16 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.

[0112] Table 8 shows various parameters of Example 3 under different states of the zoom lens group, wherein the units of f, TTL, ImgH, D4, D8 and D11 are all millimeters (mm), and the unit of FOV is degrees (°).

[0113] Parameters Telephoto state Intermediate state Wide angle state f 29.90 21.94 14.97 Fno 3.81 3.34 2.77 FOV 10.4 14.2 20.9 TTL 45.00 45.00 45.00 Ih 2.72 2.72 2.72 D4 0.03 4.07 9.27 D8 5.48 4.31 0.55 D11 4.61 1.74 0.30

[0114] Table 8

[0115] Table 9 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 3. The surface type of each aspherical surface can be defined by the formula (1) given in the above-mentioned Example 1.

[0116] Face number A4 A6 A8 A10 A12 A14 A16 S7 -2.2700E-03 6.4089E-05 -1.2382E-06 5.9809E-09 -2.1424E-10 3.6939E-12 -2.1899E-13 S8 -1.7900E-03 8.6324E-05 -5.2203E-07 -1.1815E-09 1.3198E-10 6.4118E-12 0.0000E+00

[0117] Table 9

[0118] 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.

[0119] Example 4

[0120] The following reference Figures 19 to 24D A zoom lens group according to Example 4 of the present application is described. Fig.19 A schematic diagram of the structure of the zoom lens group according to Example 4 of the present application when in a telephoto state is shown. Fig. 20 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 4 of the present application is shown. Fig.21 A schematic structural diagram of the zoom lens group according to Example 4 of the present application when in a wide-angle state is shown.

[0121] like Figure 19-21 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 S16.

[0122] The object side surface S1 of the first lens E1 is a concave surface, and the image side surface S2 is a convex surface. The object side surface S3 of the second lens E2 is a concave surface, and the image side surface S4 is a convex surface. The object side surface S5 of the third lens E3 is a convex surface, and the image side surface S6 is a convex surface. The object side surface S7 of the fourth lens E4 is a convex surface, and the image side surface S8 is a concave surface. The object side surface S9 of the fifth lens E5 is a convex surface, and the image side surface S10 is a convex surface. The object side surface S10 of the sixth lens E6 is a concave surface, and the image side surface S11 is a concave surface. The object side surface S12 of the seventh lens E7 is a convex surface, and the image side surface S13 is a concave surface. The filter E8 has an object side surface S14 and an image side surface S15. The light from the object passes through each surface S1 to S15 in sequence and is finally imaged on the imaging surface S16.

[0123] Table 10 shows the basic parameter table of the zoom lens group of Example 4, wherein the units of the curvature radius and thickness / distance are both millimeters (mm).

[0124]

[0125] Table 10

[0126] 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 D11 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 S16 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.

[0127] Table 11 shows the parameters of Example 4 in different states of the zoom lens group, wherein the units of f, TTL, ImgH, D4, D8 and D11 are all millimeters (mm), and the unit of FOV is degrees (°).

[0128] Parameters Telephoto state Intermediate state Wide angle state f 27.18 15.71 9.09 Fno 3.81 2.85 1.96 FOV 10.9 19.2 34.2 TTL 45.00 45.00 45.00 Ih 2.72 2.72 2.72 D4 0.03 5.20 12.28 D8 2.34 5.25 0.86 D11 10.77 2.70 0.00

[0129] Table 11

[0130] Table 12 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, 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.

[0131] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S7 -2.3600E-03 6.2320E-05 -1.1313E-06 4.4893E-09 -5.8635E-11 -6.0481E-12 1.8487E-13 -5.9618E-15 0.0000E+00 S8 -1.8800E-03 8.1984E-05 5.1453E-07 -2.6891E-08 9.2734E-11 6.7969E-11 -4.2829E-12 1.5966E-13 -2.2922E-15

[0132] Table 12

[0133] Fig.22A , 23A 24A respectively show the axial chromatic aberration curves when the zoom lens group of Example 4 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. 22B , 23B 24B and 24B respectively show the astigmatism curves of the zoom lens group of Example 4 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. 22C , 23C 24C respectively show the distortion curves of the zoom lens group of Example 4 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.22D , 23D24D respectively show the magnification chromatic aberration curves when the zoom lens group of Example 4 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. 22A to FIG. 24D It can be seen that the zoom lens group provided in Example 4 can achieve good imaging quality in all states.

[0134] In summary, Examples 1 to 4 respectively satisfy the relationships shown in Table 13.

[0135]

[0136]

[0137] Table 13

[0138] 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.

[0139] 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 negative optical power and its object side surface is a concave surface, and the second lens has negative optical power and its object side surface is a concave surface; a second lens group with positive optical power, comprising a third lens and a fourth lens, wherein the third lens has positive optical power, and its object side surface and image side surface are both convex surfaces, and the fourth lens has negative optical power, its object side surface is convex and its image side surface is concave; a third lens group with positive power, comprising a fifth lens and a sixth lens, wherein the fifth lens and the sixth lens are cemented together to form a cemented lens, the fifth lens has positive power, and both the object side surface and the image side surface thereof are convex, and the sixth lens has negative power, and both the object side surface and the image side surface thereof are concave; and a fourth lens group having negative optical power, comprising a seventh lens; The number of lenses having optical power in the zoom lens group is seven; 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 effective focal length F1 of the first lens group and the effective focal length F4 of the fourth lens group satisfy: 0.59≤F1 / F4≤0.

85.

3. The zoom lens assembly according to claim 1, characterized in that: The effective focal length F2 of the second lens group and the effective focal length F3 of the third lens group satisfy: 0.5<F2 / F3≤0.

86.

4. The zoom lens assembly according to claim 1, wherein: 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<3.

5. 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 the telephoto state, the total effective focal length FM of the zoom lens group when it is in the intermediate state in the process of switching from the telephoto state to the wide-angle state, the total effective focal length FW of the zoom lens group when it is in the wide-angle state, and the effective focal length f11 of the first lens satisfy: -1.25≤(FT+FM+FW) / f11≤-0.

3.

6. The zoom lens assembly according to claim 1, characterized in that: The effective focal length f31 of the fifth lens, the effective focal length f32 of the sixth lens, the effective focal length f21 of the third lens and the effective focal length f22 of the fourth lens satisfy: 0.6<(f31-f32) / (f21-f22)≤0.

92.

7. The zoom lens assembly according to claim 1, characterized in that: The maximum field of view angle FOVT of the zoom lens group when in a telephoto state satisfies: 10.4°≤FOVT≤11.1°.

8. The zoom lens assembly according to claim 1, wherein: A curvature radius R7 of the object-side surface of the fourth lens and a curvature radius R8 of the image-side surface of the fourth lens satisfy: 0.40≤(R7-R8) / (R7+R8)<0.

5.

9. The zoom lens assembly according to claim 1, wherein: A center thickness CT3 of the third lens on the optical axis, a center thickness CT4 of the fourth lens on the optical axis, and a center thickness CT1 of the first lens on the optical axis satisfy: 0.51≤(CT3+CT4) / CT1<0.

6.

10. The zoom lens assembly according to claim 1, wherein: A center thickness CT1 of the first lens on the optical axis and a spacing distance T12 between the first lens and the second lens on the optical axis satisfy the following: 10.15 mm ≤ CT1 + T12 ≤ 10.70 mm.

11. The zoom lens assembly according to claim 1, wherein: The effective focal length f12 of the second lens and the curvature radius R1 of the object-side surface of the first lens satisfy: 0.1<f12 / R1≤1.40.

Images