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 positive optical power, including a first lens with optical power and a second lens with optical power arranged in order along the optical axis; a second lens group with negative optical power, including a third lens with negative optical power and a fourth lens with optical power arranged in order along the optical axis; and a third lens group with positive optical power, including a fifth lens with positive optical power and a convex surface on the object side and the image side, a sixth lens with optical power, a seventh lens with negative optical power and a concave surface on the object side and the image side, and an eighth lens with optical power arranged in order along the optical axis. The positions of the second lens group and the third lens group on the optical axis are adjustable.

Description

Technical Field

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

[0002] In recent years, with the rapid development of smart terminals such as mobile phones, the camera function of mobile phones and other smart terminals has become one of the main directions for major mobile phone manufacturers to compete, and various mobile phone lenses with ultra-clear camera functions are becoming increasingly popular.

[0003] Usually, the internal structure of a mobile phone lens is fixed, that is, a single mobile phone lens is a fixed-focus lens. In order to achieve the zoom function, most mobile phone manufacturers use a "baton" zoom, that is, the zoom function is mainly achieved through the combination of "wide-angle lens-main camera lens-telephoto lens". This zoom achieved by gradually enlarging the wide-angle-main camera-telephoto lens is a digital zoom. Since digital zoom is achieved by switching lenses with different focal lengths, it will cause a sudden change in the picture at the switching point, and a powerful image processing algorithm is needed to alleviate this sudden change. In addition, the use of a zoom method from one focal length to another will damage the image quality, resulting in poor user experience. 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 positive optical power, including a first lens with optical power and a second lens with optical power arranged in sequence along the optical axis; a second lens group with negative optical power, including a third lens with negative optical power and a fourth lens with optical power arranged in sequence along the optical axis; and a third lens group with positive optical power, including a fifth lens with positive optical power and a convex surface on the object side and the image side, a sixth lens with optical power, a seventh lens with negative optical power and a concave surface on the object side and the image side, and an eighth lens with optical power arranged in sequence along the optical axis. The positions of the second lens group and the third lens group on the optical axis are adjustable.

[0005] In one embodiment, the effective focal length F1 of the first lens group and the effective focal length F3 of the third lens group may satisfy: 5.0<F1 / F3<6.0.

[0006] 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 wide-angle state to the telephoto 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 f8 of the eighth lens may satisfy: 4.2<(FT+FM+FW) / f8<5.0.

[0007] In one embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens may satisfy: 2.5<(f2-f1) / (f4-f3)<5.5.

[0008] In one embodiment, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the effective focal length f7 of the seventh lens, and the effective focal length f8 of the eighth lens may satisfy: -3.3<(f5+f6) / (f7+f8)<-2.3.

[0009] In one embodiment, a center thickness CT5 of the fifth lens on the optical axis, a center thickness CT6 of the sixth lens on the optical axis, a center thickness CT7 of the seventh lens on the optical axis, a center thickness CT8 of the eighth lens on the optical axis, and a spacing distance T67 between the sixth lens and the seventh lens on the optical axis may satisfy: 1.6<T67 / (CT5+CT6+CT7+CT8)<2.1.

[0010] In one embodiment, a curvature radius R3 of the object side surface of the second lens, a curvature radius R4 of the image side surface of the second lens, a curvature radius R1 of the object side surface of the first lens, and a curvature radius R2 of the image side surface of the first lens may satisfy: 1.5<(R3+R4) / (R1+R2)<2.0.

[0011] In one embodiment, a curvature radius R5 of the object side surface of the third lens, a curvature radius R6 of the image side surface of the third lens, 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: 1.7<(R5+R6) / (R7+R8)<2.7.

[0012] In one embodiment, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis may satisfy: 1.1<(CT1+CT2) / (CT3+CT4)<1.5.

[0013] In one embodiment, the distance TTL from the object side surface of the first lens to the imaging surface of the zoom lens group on the optical axis and the effective focal length F2 of the second lens group may satisfy: -2.5<TTL / F2<-2.

[0014] In one embodiment, the total effective focal length FT when the zoom lens group is in a telephoto state and the total effective focal length FW when the zoom lens group is in a wide-angle state may satisfy: 2.0<FT / FW<3.0.

[0015] In one embodiment, at least one of the first to eighth lenses is a glass lens; and at least one of the object-side surface of the first lens to the image-side surface of the eighth lens is an aspherical mirror surface.

[0016] On the other hand, the present application provides 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 positive optical focal power; a second lens group with negative optical focal power; and a third lens group with positive optical focal power; the positions of the second lens group and the third lens group on the optical axis are adjustable; and the effective focal length F1 of the first lens group and the effective focal length F3 of the third lens group can satisfy: 5.0<F1 / F3<6.0.

[0017] In one embodiment, the first lens group includes a first lens with optical power and a second lens with optical power, which are sequentially arranged along the optical axis; the second lens group includes a third lens with negative optical power and a fourth lens with optical power, which are sequentially arranged along the optical axis; and the third lens group includes a fifth lens with positive optical power and whose object side and image side surfaces are both convex, a sixth lens with optical power, a seventh lens with negative optical power and whose object side and image side surfaces are both concave, and an eighth lens with optical power, which are sequentially arranged along the optical axis.

[0018] 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 wide-angle state to the telephoto 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 f8 of the eighth lens may satisfy: 4.2<(FT+FM+FW) / f8<5.0.

[0019] In one embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens may satisfy: 2.5<(f2-f1) / (f4-f3)<5.5.

[0020] In one embodiment, the effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the effective focal length f7 of the seventh lens, and the effective focal length f8 of the eighth lens may satisfy: -3.3<(f5+f6) / (f7+f8)<-2.3.

[0021] In one embodiment, a center thickness CT5 of the fifth lens on the optical axis, a center thickness CT6 of the sixth lens on the optical axis, a center thickness CT7 of the seventh lens on the optical axis, a center thickness CT8 of the eighth lens on the optical axis, and a spacing distance T67 between the sixth lens and the seventh lens on the optical axis may satisfy: 1.6<T67 / (CT5+CT6+CT7+CT8)<2.1.

[0022] In one embodiment, a curvature radius R3 of the object side surface of the second lens, a curvature radius R4 of the image side surface of the second lens, a curvature radius R1 of the object side surface of the first lens, and a curvature radius R2 of the image side surface of the first lens may satisfy: 1.5<(R3+R4) / (R1+R2)<2.0.

[0023] In one embodiment, a curvature radius R5 of the object side surface of the third lens, a curvature radius R6 of the image side surface of the third lens, 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: 1.7<(R5+R6) / (R7+R8)<2.7.

[0024] In one embodiment, the center thickness CT1 of the first lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third lens on the optical axis, and the center thickness CT4 of the fourth lens on the optical axis may satisfy: 1.1<(CT1+CT2) / (CT3+CT4)<1.5.

[0025] In one embodiment, the distance TTL from the object side surface of the first lens to the imaging surface of the zoom lens group on the optical axis and the effective focal length F2 of the second lens group may satisfy: -2.5<TTL / F2<-2.

[0026] In one embodiment, the total effective focal length FT when the zoom lens group is in a telephoto state and the total effective focal length FW when the zoom lens group is in a wide-angle state may satisfy: 2.0<FT / FW<3.0.

[0027] In one embodiment, at least one of the first to eighth lenses is a glass lens; and at least one of the object-side surface of the first lens to the image-side surface of the eighth lens is an aspherical mirror surface.

[0028] The present application provides a zoom lens group with continuous zoom, smooth image transition during zooming, miniaturization and good imaging quality by reasonably allocating optical focal length and optimizing optical parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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:

[0030] Figure 1 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 1 of the present application is shown;

[0031] Figure 2 A schematic structural diagram showing an intermediate state of a zoom lens assembly in a process of switching from a wide-angle state to a telephoto state according to Embodiment 1 of the present application is shown;

[0032] Figure 3 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 1 of the present application is shown;

[0033] 4A to 4D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the zoom lens group of Example 1 when it is in a wide-angle state are respectively shown;

[0034] 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 wide-angle state to the telephoto state are respectively shown;

[0035] FIG. 6A to FIG. 6D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the zoom lens group of Example 1 when it is in a telephoto state are respectively shown;

[0036] Figure 7 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 2 of the present application is shown;

[0037] Figure 8 A schematic structural diagram showing an intermediate state of a zoom lens assembly in a process of switching from a wide-angle state to a telephoto state according to Embodiment 2 of the present application;

[0038] Fig. 9 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 2 of the present application is shown;

[0039] FIG. 10A to FIG. 10D 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;

[0040] FIG. 11A to FIG. 11D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the lateral chromatic aberration curve of the zoom lens group of Example 2 in the intermediate state when the zoom lens group is switched from the wide-angle state to the telephoto state are respectively shown;

[0041] 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 the telephoto state;

[0042] Fig.13 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 3 of the present application is shown;

[0043] Fig.14 A schematic structural diagram showing an intermediate state of a zoom lens assembly in a process of switching from a wide-angle state to a telephoto state according to Embodiment 3 of the present application is shown;

[0044] Fig.15 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 3 of the present application is shown;

[0045] FIG. 16A to FIG. 16D 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;

[0046] 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 wide-angle state to the telephoto state are respectively shown;

[0047] 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 telephoto state are respectively shown;

[0048] Fig.19 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 4 of the present application is shown;

[0049] Fig. 20 A schematic structural diagram showing an intermediate state of a zoom lens assembly in a process of switching from a wide-angle state to a telephoto state according to Embodiment 4 of the present application;

[0050] Fig.21 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 4 of the present application is shown;

[0051] FIG. 22A to FIG. 22D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the zoom lens group of Example 4 when in a wide-angle state are respectively shown;

[0052] 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 intermediate state when the zoom lens group is switched from the wide-angle state to the telephoto state are respectively shown;

[0053] FIG. 24A to FIG. 24D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the zoom lens group of Example 4 when it is in a telephoto state are respectively shown;

[0054] Fig.25 A schematic structural diagram of a zoom lens assembly in a wide-angle state according to Embodiment 5 of the present application is shown;

[0055] Fig.26A schematic structural diagram showing an intermediate state of a zoom lens assembly in a process of switching from a wide-angle state to a telephoto state according to Embodiment 5 of the present application;

[0056] Fig. 27 A schematic structural diagram of a zoom lens assembly in a telephoto state according to Embodiment 5 of the present application is shown;

[0057] FIG. 28A to FIG. 28D The axial chromatic aberration curve, astigmatism curve, distortion curve and magnification chromatic aberration curve of the zoom lens group of Example 5 when in a wide-angle state are respectively shown;

[0058] FIG. 29A to FIG. 29D The axial chromatic aberration curve, the astigmatism curve, the distortion curve and the lateral chromatic aberration curve of the zoom lens group of Example 5 in the intermediate state when the zoom lens group is switched from the wide-angle state to the telephoto state are respectively shown; and

[0059] FIG. 30A to FIG. 30D The axial chromatic aberration curve, astigmatism curve, distortion curve and lateral chromatic aberration curve of the zoom lens group of Example 5 when in the telephoto state are respectively shown. DETAILED DESCRIPTION

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as those 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.

[0066] 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.

[0067] The features, principles and other aspects of the present application are described in detail below.

[0068] The zoom lens group according to the exemplary embodiment of the present application may include three lens groups with optical power, namely a first lens group, a second lens group and a third lens group. The three lens groups are arranged in sequence from the object side to the image side along the optical axis. Both the second lens group and the third lens group can be moved on the optical axis, and the zoom lens group can be continuously zoomed by changing the positions of the second lens group and the third lens group on the optical axis.

[0069] In an exemplary embodiment, 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 an imaging surface. By changing the positions of the second lens group, the third lens group, and the filter and / or the protective glass on the optical axis, the zoom lens group may be continuously zoomed.

[0070] In an exemplary embodiment, when the second lens group moves on the optical axis, the focal length of the zoom lens group changes, causing additional optical path difference in the light rays reaching the image plane, resulting in a reduction in image quality. At this time, the optical path difference caused by the second lens group is compensated by synchronously adjusting the position of the third lens group on the optical axis to maintain stable image quality.

[0071] The zoom lens group according to the exemplary embodiment of the present application may include eight lenses with optical power, namely, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The eight lenses are arranged in sequence from the object side to the image side along the optical axis. The first lens and the second lens may constitute a first lens group; the third lens and the fourth lens may constitute a second lens group; the fifth lens, the sixth lens, the seventh lens, and the eighth lens may constitute a third lens group.

[0072] In example embodiments, the first lens group may have positive power; the second lens group may have negative power; and the third lens group may have positive power.

[0073] In an exemplary embodiment, the first lens may have positive optical power or negative optical power; the second lens may have positive optical power or negative optical power; the third lens may have negative optical power; the fourth lens may have positive optical power or negative optical power; the fifth lens may have positive optical power, and its object side surface may be convex and its image side surface may be convex; the sixth lens may have positive optical power or negative optical power; the seventh lens may have negative optical power, and its object side surface may be concave and its image side surface may be concave; and the eighth lens may have positive optical power or negative optical power.

[0074] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 5.0<F1 / F3<6.0, where F1 is the effective focal length of the first lens group, and F3 is the effective focal length of the third lens group. More specifically, F1 and F3 may further satisfy: 5.2<F1 / F3<5.5. Satisfying 5.0<F1 / F3<6.0 is conducive to reasonably configuring the optical power of each lens and reducing aberrations.

[0075] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 4.2<(FT+FM+FW) / f8<5.0, 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 wide-angle state to a telephoto state, FW is the total effective focal length of the zoom lens group when it is in a wide-angle state, and f8 is the effective focal length of the eighth lens. More specifically, FT, FM, FW, and f8 may further satisfy: 4.3<(FT+FM+FW) / f8<5.0. Satisfying 4.2<(FT+FM+FW) / f8<5.0 is beneficial for the eighth lens to compensate for the optical path difference and ensure image quality.

[0076] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 2.5<(f2-f1) / (f4-f3)<5.5, wherein f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, and f4 is the effective focal length of the fourth lens. More specifically, f2, f1, f4, and f3 may further satisfy: 2.7<(f2-f1) / (f4-f3)<5.5. Satisfying 2.5<(f2-f1) / (f4-f3)<5.5 is conducive to rationally configuring the optical power of each lens and reducing aberrations.

[0077] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: -3.3<(f5+f6) / (f7+f8)<-2.3, wherein f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, f7 is the effective focal length of the seventh lens, and f8 is the effective focal length of the eighth lens. More specifically, f5, f6, f7, and f8 may further satisfy: -3.2<(f5+f6) / (f7+f8)<-2.6. Satisfying -3.3<(f5+f6) / (f7+f8)<-2.3 is conducive to rationally configuring the optical power of each lens and reducing aberrations.

[0078] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 1.6<T67 / (CT5+CT6+CT7+CT8)<2.1, wherein CT5 is the center thickness of the fifth lens on the optical axis, CT6 is the center thickness of the sixth lens on the optical axis, CT7 is the center thickness of the seventh lens on the optical axis, CT8 is the center thickness of the eighth lens on the optical axis, and T67 is the spacing distance between the sixth lens and the seventh lens on the optical axis. More specifically, T67, CT5, CT6, CT7, and CT8 may further satisfy: 1.7<T67 / (CT5+CT6+CT7+CT8)<2.0. Satisfying 1.6<T67 / (CT5+CT6+CT7+CT8)<2.1 is beneficial to the spatial distribution of each lens.

[0079] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 1.5<(R3+R4) / (R1+R2)<2.0, wherein R3 is the radius of curvature of the object side surface of the second lens, R4 is the radius of curvature of the image side surface of the second lens, R1 is the radius of curvature of the object side surface of the first lens, and R2 is the radius of curvature of the image side surface of the first lens. More specifically, R3, R4, R1, and R2 may further satisfy: 1.6<(R3+R4) / (R1+R2)<2.0. Satisfying 1.5<(R3+R4) / (R1+R2)<2.0 is conducive to reasonably adjusting the aberration contribution of the first lens and the second lens to the zoom lens group.

[0080] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 1.7<(R5+R6) / (R7+R8)<2.7, wherein R5 is the radius of curvature of the object side surface of the third lens, R6 is the radius of curvature of the image side surface of the third lens, 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. More specifically, R5, R6, R7, and R8 may further satisfy: 1.9<(R5+R6) / (R7+R8)<2.6. Satisfying 1.7<(R5+R6) / (R7+R8)<2.7 is conducive to reasonably adjusting the aberration contribution of the third lens and the fourth lens to the zoom lens group.

[0081] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 1.1<(CT1+CT2) / (CT3+CT4)<1.5, wherein CT1 is the center thickness of the first lens on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third lens on the optical axis, and CT4 is the center thickness of the fourth lens on the optical axis. More specifically, CT1, CT2, CT3, and CT4 may further satisfy: 1.2<(CT1+CT2) / (CT3+CT4)<1.4. Satisfying 1.1<(CT1+CT2) / (CT3+CT4)<1.5 is conducive to avoiding the influence of excessive thickness of the lens on the spatial distribution of the lens, and is convenient for assembling the zoom lens group.

[0082] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: -2.5<TTL / F2<-2, wherein TTL is the distance from the object side of the first lens to the imaging surface of the zoom lens group on the optical axis, and F2 is the effective focal length of the second lens group. More specifically, TTL and F2 may further satisfy: -2.4<TTL / F2<-2.2. Satisfying -2.5<TTL / F2<-2 is conducive to maintaining the focal length of the second lens group within a reasonable range, thereby facilitating the control of the zoom range of the entire lens group.

[0083] In an exemplary embodiment, the zoom lens group according to the present application may satisfy: 2.0<FT / FW<3.0, where FT is the total effective focal length when the zoom lens group is in a telephoto state, and FW is the total effective focal length when the zoom lens group is in a wide-angle state. More specifically, FT and FW may further satisfy: 2.5<FT / FW<2.7. Satisfying 2.0<FT / FW<3.0 is conducive to the zoom lens group to achieve two to three times optical continuous zoom.

[0084] In an exemplary embodiment, at least one of the first lens to the eighth lens is a glass lens; and at least one of the object side surface of the first lens to the image side surface of the eighth lens is an aspherical mirror surface. Preferably, at least one surface of the glass lens is an aspherical mirror surface. Using a lens made of glass and having an aspherical mirror surface can better correct the chromatic aberration of the lens group and is conducive to improving the temperature drift effect.

[0085] In an exemplary embodiment, the zoom lens group according to the present application also includes an aperture stop arranged between the second lens group and the third lens group. For example, the aperture stop can be set at the object side of the fifth lens close to the second lens in the third lens group. The present application proposes a zoom lens group with the characteristics of continuous zoom, smooth picture transition during zooming, miniaturization, high imaging quality, etc. The zoom lens group provided by the present application is a zoom lens group in a purely optical sense, which realizes the zoom function by changing the structure inside the lens. By changing the focal length of the lens group itself, a smooth transition of image quality during continuous zooming (such as from a wide-angle state to a telephoto state) can be achieved, and the problem of image quality being easily damaged when the lens group is in a telephoto state can be effectively avoided. In the same case, if combined with digital zoom, a larger hybrid zoom range can be achieved.

[0086] The zoom lens set according to the above embodiment of the present application may use multiple lenses, such as the eight lenses described above. By reasonably allocating the focal length, surface shape, center thickness of each lens, and axial spacing between lenses, 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 set more conducive to production and processing.

[0087] 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 eighth 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, the seventh lens and the eighth 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, the seventh lens and the eighth lens are all aspherical mirror surfaces. Optionally, the object side surface and the image side surface of the first lens are both spherical mirror surfaces; the object side surface and the image side surface of each of the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are both aspherical mirror surfaces.

[0088] However, those skilled in the art should understand 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 eight lenses are described as an example in the embodiments, the zoom lens group is not limited to including eight lenses. If necessary, the zoom lens group may also include other numbers of lenses.

[0089] Specific embodiments of the zoom lens assembly applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0090] Example 1

[0091] The following reference Figures 1 to 6D A zoom lens group according to Embodiment 1 of the present application is described. Figure 1 A schematic structural diagram of a zoom lens group in a wide-angle 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 wide-angle state to a telephoto state according to Embodiment 1 of the present application is shown. Figure 3 A schematic structural diagram of a zoom lens group in a telephoto state according to Embodiment 1 of the present application is shown.

[0092] like Figure 1-Figure 3As 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), an aperture STO, a third lens group G3 (a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8), a filter E9 and an imaging surface S19.

[0093] 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 convex, 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 concave. 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, wherein the aperture STO may be arranged at the object side surface S9 of the fifth lens E5. 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 concave. The object side surface S15 of the eighth lens E8 is convex, and the image side surface S16 is convex. The filter E9 has an object side surface S17 and an image side surface S18. Light from the object passes through each surface S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0094] Table 1 shows the basic parameters of the zoom lens set of Example 1, wherein the units of the curvature radius, thickness / distance and focal length are all millimeters (mm).

[0095]

[0096]

[0097] Table 1

[0098] In this example, continuous zooming of the zoom lens group can be achieved by changing the positions of the second lens group, the third lens group and the filter on the optical axis. In other words, the zoom lens group can be switched from a wide-angle state to a telephoto state or from a telephoto state to a wide-angle 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 between the image side surface of the second lens E2 and the object side surface of the third lens E3 on the optical axis), the spacing distance D8 between the second lens group and the third lens group on the optical axis (i.e., the spacing distance between the image side surface of the fourth lens E4 and the object side surface of the fifth lens E5 on the optical axis), the spacing distance D17 between the third lens group and the filter on the optical axis (i.e., the spacing distance between the image side surface of the eighth lens E8 and the object side surface of the filter E9 on the optical axis), and the spacing distance D19 between the filter and the imaging surface on the optical axis (i.e., the spacing distance between the image side surface of the filter E9 and the imaging surface S19 on the optical axis). The total effective focal length F, the maximum field angle FOV, and the aperture value Fno of the zoom lens group change as the zoom lens group switches from the wide-angle state to the telephoto state or from the telephoto state to the wide-angle state.

[0099] Table 2 shows the parameters of Example 1 that change with different states of the zoom lens group, wherein the units of F, D4, D8, D17 and D19 are all millimeters (mm), and the unit of FOV is degrees (°).

[0100] F FOV Fno D4 D8 D17 D19 Wide angle state 10.07 33.6 2.61 1.18 7.61 1.36 0.12 Intermediate state 14.38 22.9 3.00 3.25 4.5 2.17 0.35 Telephoto state 26.02 12.9 4.34 3.66 0.48 5.68 0.45

[0101] Table 2

[0102] In this example, the total length 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 S19 of the zoom lens group) TTL is 24.41 mm, and half of the diagonal length of the effective pixel area on the imaging surface S19 of the zoom lens group ImgH is 2.90 mm.

[0103] In Example 1, the object-side surface and the image-side surface of the first lens E1 to the eighth lens E8 are all aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0104]

[0105] 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 , A14 , A 16 , A 18 and A 20 .

[0106]

[0107]

[0108] Table 3

[0109] Figure 4A , Figure 5A , Fig. 6A The axial chromatic aberration curves of the zoom lens group of Example 1 when in the wide-angle state, the intermediate state and the telephoto state are respectively shown, which indicate the deviation of the focusing point of light rays of different wavelengths passing through the back of the lens. Figure 4B , Figure 5B , Figure 6B Astigmatism curves are shown when the zoom lens group of Example 1 is in a wide-angle state, a middle state, and a telephoto state, respectively, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 4C , Figure 5C , Figure 6C Distortion curves of the zoom lens group of Example 1 when in a wide-angle state, a middle state and a telephoto 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 wide-angle state, the intermediate state and the telephoto 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 set provided in Example 1 can achieve good imaging quality in all states.

[0110] Example 2

[0111] 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 structural diagram of a zoom lens group in a wide-angle state according to Embodiment 2 of the present application is shown. Figure 8 A schematic structural diagram of an intermediate state of a zoom lens group in a process of switching from a wide-angle state to a telephoto state according to Embodiment 2 of the present application is shown. Fig. 9 A schematic structural diagram of a zoom lens group in a telephoto state according to Embodiment 2 of the present application is shown.

[0112] like Figure 7-Figure 9As 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), an aperture STO, a third lens group G3 (a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8), a filter E9 and an imaging surface S19.

[0113] 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 convex, 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 concave. 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, wherein the aperture STO may be arranged at the object side surface S9 of the fifth lens E5. 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 concave. The object side surface S15 of the eighth lens E8 is convex, and the image side surface S16 is concave. The filter E9 has an object side surface S17 and an image side surface S18. Light from the object passes through each surface S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0114] In this example, the total length TTL of the zoom lens group is 24.45 mm, and half of the diagonal length ImgH of the effective pixel area on the imaging surface S19 of the zoom lens group is 2.90 mm.

[0115] Table 4 shows a basic parameter table of the zoom lens set of Example 2, wherein the units of the curvature radius, thickness / distance and focal length are all millimeters (mm).

[0116]

[0117] Table 4

[0118] In this example, continuous zooming of the zoom lens group can be achieved by changing the positions of the second lens group, the third lens group and the filter on the optical axis. In other words, the zoom lens group can be switched from a wide-angle state to a telephoto state or from a telephoto state to a wide-angle 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 between the image side surface of the second lens E2 and the object side surface of the third lens E3 on the optical axis), the spacing distance D8 between the second lens group and the third lens group on the optical axis (i.e., the spacing distance between the image side surface of the fourth lens E4 and the object side surface of the fifth lens E5 on the optical axis), the spacing distance D17 between the third lens group and the filter on the optical axis (i.e., the spacing distance between the image side surface of the eighth lens E8 and the object side surface of the filter E9 on the optical axis), and the spacing distance D19 between the filter and the imaging surface on the optical axis (i.e., the spacing distance between the image side surface of the filter E9 and the imaging surface S19 on the optical axis). The total effective focal length F, the maximum field angle FOV, and the aperture value Fno of the zoom lens group change as the zoom lens group switches from the wide-angle state to the telephoto state or from the telephoto state to the wide-angle state.

[0119] Table 5 shows a table of parameters that change with different states of the zoom lens group in Example 2, wherein the units of F, D4, D8, D17 and D19 are all millimeters (mm), and the unit of FOV is degrees (°).

[0120] F FOV Fno D4 D8 D17 D19 Wide angle state 10.17 33.0 2.68 1.08 7.61 1.36 0.17 Intermediate state 14.48 22.7 3.07 3.16 4.49 2.17 0.40 Telephoto state 26.00 12.8 4.41 3.56 0.48 5.68 0.49

[0121] Table 5

[0122] 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.

[0123] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 3.9701E-04 -2.0215E-04 1.6742E-04 -6.0264E-05 8.0548E-06 1.8406E-06 -1.1468E-06 2.8131E-07 -4.2492E-08 S2 5.4493E-03 -8.0596E-03 6.2419E-03 -2.6769E-03 6.1922E-04 -3.4856E-05 -2.5044E-05 9.2495E-06 -1.7024E-06 S3 5.4493E-03 -8.0596E-03 6.2419E-03 -2.6769E-03 6.1922E-04 -3.4856E-05 -2.5044E-05 9.2495E-06 -1.7024E-06 S4 -9.4356E-04 2.3155E-03 -2.1296E-03 1.2258E-03 -4.6933E-04 1.2291E-04 -2.1978E-05 2.5764E-06 -1.7108E-07 S5 -4.6653E-03 2.9169E-04 -1.7126E-05 8.1782E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 -5.8408E-03 -4.1820E-04 3.6138E-05 9.9788E-07 -1.3092E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 -3.2915E-03 -5.4397E-05 7.3813E-04 -2.3901E-03 2.8244E-03 -1.9211E-03 8.5138E-04 -2.5861E-04 5.4946E-05 S8 -6.2012E-03 2.5932E-03 -2.2481E-03 6.7835E-04 8.3798E-04 -1.1237E-03 6.6663E-04 -2.4418E-04 5.9841E-05 S9 -8.2249E-04 -7.1444E-05 -1.0568E-05 5.9034E-07 -5.6695E-08 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 3.5712E-03 -6.5298E-04 1.3131E-04 -1.3852E-05 5.9286E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 -5.7003E-03 8.5677E-03 -2.2993E-02 3.8699E-02 -4.2039E-02 3.1048E-02 -1.6098E-02 5.9641E-03 -1.5873E-03 S12 -7.2611E-03 1.6971E-02 -5.0720E-02 9.6408E-02 -1.1844E-01 9.8823E-02 -5.7811E-02 2.4136E-02 -7.2307E-03 S13 1.3052E-02 -1.0600E-01 3.3802E-01 -6.6786E-01 8.6904E-01 -7.7737E-01 4.9105E-01 -2.2221E-01 7.2274E-02 S14 -1.2629E-01 4.4259E-01 -7.2110E-01 5.3117E-01 -2.1500E-02 -2.9957E-01 2.8525E-01 -1.4506E-01 4.7389E-02 S15 -1.3798E-01 5.0212E-01 -9.3240E-01 9.7593E-01 -6.0062E-01 1.9750E-01 -7.7107E-03 -2.3724E-02 1.1757E-02 S16 -3.5519E-02 1.1694E-01 -2.5812E-01 3.6040E-01 -3.4082E-01 2.2796E-01 -1.1026E-01 3.8899E-02 -9.9883E-03

[0124] Table 6

[0125] Fig. 10A , 11A 12A and 12B respectively show the axial chromatic aberration curves when the zoom lens group of Example 2 is in the wide-angle state, the intermediate state and the telephoto 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 wide-angle state, the intermediate state and the telephoto 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 wide-angle state, the middle state and the telephoto 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 wide-angle state, the intermediate state and the telephoto 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 set provided in Example 2 can achieve good imaging quality in all states.

[0126] Example 3

[0127] The following reference Figures 13 to 18D A zoom lens group according to Embodiment 3 of the present application is described. Fig.13 A schematic structural diagram of a zoom lens group in a wide-angle state according to Embodiment 3 of the present application is shown. Fig.14 A schematic structural diagram of an intermediate state of a zoom lens group in a process of switching from a wide-angle state to a telephoto state according to Embodiment 3 of the present application is shown. Fig.15 A schematic structural diagram of a zoom lens group in a telephoto state according to Embodiment 3 of the present application is shown.

[0128] 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), an aperture STO, a third lens group G3 (a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8), a filter E9 and an imaging surface S19.

[0129] 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 convex, 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 concave. 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, wherein the aperture STO may be arranged at the object side surface S9 of the fifth lens E5. 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 concave. The object side surface S15 of the eighth lens E8 is convex, and the image side surface S16 is concave. The filter E9 has an object side surface S17 and an image side surface S18. Light from the object passes through each surface S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0130] In this example, the total length TTL of the zoom lens group is 24.50 mm, and half of the diagonal length ImgH of the effective pixel area on the imaging surface S19 of the zoom lens group is 2.90 mm.

[0131] Table 7 shows a basic parameter table of the zoom lens group of Example 3, wherein the units of the curvature radius, thickness / distance and focal length are all millimeters (mm).

[0132]

[0133] Table 7

[0134] In this example, continuous zooming of the zoom lens group can be achieved by changing the positions of the second lens group, the third lens group and the filter on the optical axis. In other words, the zoom lens group can be switched from a wide-angle state to a telephoto state or from a telephoto state to a wide-angle 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 between the image side surface of the second lens E2 and the object side surface of the third lens E3 on the optical axis), the spacing distance D8 between the second lens group and the third lens group on the optical axis (i.e., the spacing distance between the image side surface of the fourth lens E4 and the object side surface of the fifth lens E5 on the optical axis), the spacing distance D17 between the third lens group and the filter on the optical axis (i.e., the spacing distance between the image side surface of the eighth lens E8 and the object side surface of the filter E9 on the optical axis), and the spacing distance D19 between the filter and the imaging surface on the optical axis (i.e., the spacing distance between the image side surface of the filter E9 and the imaging surface S19 on the optical axis). The total effective focal length F, the maximum field angle FOV, and the aperture value Fno of the zoom lens group change as the zoom lens group switches from the wide-angle state to the telephoto state or from the telephoto state to the wide-angle state.

[0135] Table 8 shows a table of parameters that change with different states of the zoom lens group in Example 3, wherein the units of F, D4, D8, D17 and D19 are all millimeters (mm), and the unit of FOV is degrees (°).

[0136] F FOV Fno D4 D8 D17 D19 Wide angle state 10.17 33.1 2.67 1.09 7.66 1.35 0.16 Intermediate state 14.48 22.7 3.05 3.16 4.54 2.17 0.39 Telephoto state 26.00 12.8 4.38 3.57 0.52 5.67 0.49

[0137] Table 8

[0138] Table 9 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 3, wherein each aspherical surface shape can be defined by the formula (1) given in the above Example 1.

[0139] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 1.8144E-04 4.8222E-04 -6.8153E-04 5.4402E-04 -2.6914E-04 8.8399E-05 -2.0096E-05 3.2338E-06 -3.7110E-07 S2 4.2503E-03 -1.7992E-03 -3.0025E-03 4.7542E-03 -3.1599E-03 1.2608E-03 -3.3435E-04 6.1492E-05 -7.9703E-06 S3 4.2503E-03 -1.7992E-03 -3.0025E-03 4.7542E-03 -3.1599E-03 1.2608E-03 -3.3435E-04 6.1492E-05 -7.9703E-06 S4 -1.1126E-03 2.1139E-03 -1.5312E-03 6.1266E-04 -1.0650E-04 -1.6776E-05 1.4753E-05 -4.1695E-06 7.0026E-07 S5 -4.6513E-03 3.0193E-04 -1.6840E-05 7.4931E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 -5.6322E-03 -3.6317E-04 3.6024E-05 4.6503E-07 -1.2523E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 -3.8029E-03 2.5406E-03 -3.8423E-03 2.8070E-03 -1.1649E-03 2.2256E-04 2.8562E-05 -3.0693E-05 9.3627E-06 S8 -7.0596E-03 5.9538E-03 -8.9053E-03 8.9077E-03 -5.9550E-03 2.7716E-03 -9.2220E-04 2.2245E-04 -3.9012E-05 S9 -1.0125E-03 -5.3325E-05 -1.1173E-05 4.1901E-07 -2.9120E-08 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 3.3153E-03 -6.6260E-04 1.3175E-04 -1.3755E-05 5.9904E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 -3.8788E-03 5.5880E-03 -1.4576E-02 2.2869E-02 -2.3316E-02 1.6238E-02 -7.9430E-03 2.7707E-03 -6.9173E-04 S12 -4.8524E-03 1.1478E-02 -3.4625E-02 6.5717E-02 -8.0683E-02 6.7247E-02 -3.9234E-02 1.6302E-02 -4.8489E-03 S13 1.8182E-02 -9.5873E-02 2.6938E-01 -5.1276E-01 6.6479E-01 -6.0102E-01 3.8668E-01 -1.7923E-01 6.0018E-02 S14 -4.6770E-02 1.3802E-01 -8.6913E-02 -2.7507E-01 6.3988E-01 -6.5725E-01 4.1078E-01 -1.7100E-01 4.9067E-02 S15 -7.2187E-02 2.1411E-01 -2.7915E-01 7.6719E-02 2.1310E-01 -3.0876E-01 2.1438E-01 -9.3234E-02 2.7281E-02 S16 -3.1470E-02 8.3121E-02 -1.6637E-01 2.2067E-01 -2.0354E-01 1.3534E-01 -6.5876E-02 2.3543E-02 -6.1390E-03

[0140] Table 9

[0141] Fig.16A , 17A 18A respectively show the axial chromatic aberration curves when the zoom lens group of Example 3 is in the wide-angle state, the intermediate state and the telephoto state, which indicate that light of different wavelengths deviates from the focal point behind the lens. Fig. 16B , 17B18B and 18B respectively show the astigmatism curves of the zoom lens group of Example 3 when it is in the wide-angle state, the intermediate state and the telephoto 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 wide-angle state, the middle state and the telephoto 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 wide-angle state, the intermediate state and the telephoto state, which represent the deviation of the 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.

[0142] Example 4

[0143] The following reference Figures 19 to 24D A zoom lens group according to Embodiment 4 of the present application is described. Fig.19 A schematic structural diagram of a zoom lens group in a wide-angle state according to Embodiment 4 of the present application is shown. Fig. 20 A schematic structural diagram of an intermediate state of a zoom lens group in a process of switching from a wide-angle state to a telephoto state according to Embodiment 4 of the present application is shown. Fig.21 A schematic structural diagram of a zoom lens group in a telephoto state according to Embodiment 4 of the present application is shown.

[0144] 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), an aperture STO, a third lens group G3 (a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8), a filter E9 and an imaging surface S19.

[0145] 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 convex, 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 concave. 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, wherein the aperture STO may be arranged at the object side surface S9 of the fifth lens E5. 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 concave. The object side surface S15 of the eighth lens E8 is convex, and the image side surface S16 is concave. The filter E9 has an object side surface S17 and an image side surface S18. Light from the object passes through each surface S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0146] In this example, the total length TTL of the zoom lens group is 24.50 mm, and half of the diagonal length ImgH of the effective pixel area on the imaging surface S19 of the zoom lens group is 2.90 mm.

[0147] Table 10 shows a basic parameter table of the zoom lens group of Example 4, wherein the units of the curvature radius, thickness / distance and focal length are all millimeters (mm).

[0148]

[0149]

[0150] Table 10

[0151] In this example, continuous zooming of the zoom lens group can be achieved by changing the positions of the second lens group, the third lens group and the filter on the optical axis. In other words, the zoom lens group can be switched from a wide-angle state to a telephoto state or from a telephoto state to a wide-angle 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 between the image side surface of the second lens E2 and the object side surface of the third lens E3 on the optical axis), the spacing distance D8 between the second lens group and the third lens group on the optical axis (i.e., the spacing distance between the image side surface of the fourth lens E4 and the object side surface of the fifth lens E5 on the optical axis), the spacing distance D17 between the third lens group and the filter on the optical axis (i.e., the spacing distance between the image side surface of the eighth lens E8 and the object side surface of the filter E9 on the optical axis), and the spacing distance D19 between the filter and the imaging surface on the optical axis (i.e., the spacing distance between the image side surface of the filter E9 and the imaging surface S19 on the optical axis). The total effective focal length F, the maximum field angle FOV, and the aperture value Fno of the zoom lens group change as the zoom lens group switches from the wide-angle state to the telephoto state or from the telephoto state to the wide-angle state.

[0152] Table 11 shows a table of parameters that change with different states of the zoom lens group in Example 4, wherein the units of F, D4, D8, D17 and D19 are all millimeters (mm), and the unit of FOV is degrees (°).

[0153] F FOV Fno D4 D8 D17 D19 Wide angle state 10.17 33.2 2.67 1.11 7.64 1.39 0.19 Intermediate state 14.48 22.6 3.06 3.19 4.50 2.21 0.43 Telephoto state 26.00 12.8 4.39 3.61 0.49 5.71 0.52

[0154] Table 11

[0155] Table 12 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 4, wherein each aspherical surface shape can be defined by the formula (1) given in the above Example 1.

[0156]

[0157]

[0158] Table 12

[0159] Fig.22A , 23A 24A respectively show the axial chromatic aberration curves when the zoom lens group of Example 4 is in the wide-angle state, the middle state and the telephoto state, which indicate that light of different wavelengths deviates 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 wide-angle state, the intermediate state and the telephoto 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 wide-angle state, the middle state and the telephoto state, which represent the distortion magnitude values ​​corresponding to different image heights. Fig.22D , 23D 24D respectively show the magnification chromatic aberration curves when the zoom lens group of Example 4 is in the wide-angle state, the intermediate state and the telephoto state, which represent the deviation of the 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.

[0160] Example 5

[0161] The following reference Figures 25 to 30D A zoom lens group according to Example 5 of the present application is described. Fig.25 A schematic structural diagram of a zoom lens group in a wide-angle state according to Embodiment 5 of the present application is shown. Fig.26 A schematic structural diagram of an intermediate state of a zoom lens group in a process of switching from a wide-angle state to a telephoto state according to Embodiment 5 of the present application is shown. Fig. 27A schematic structural diagram of a zoom lens group in a telephoto state according to Embodiment 5 of the present application is shown.

[0162] like Figure 25-27 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), an aperture STO, a third lens group G3 (a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8), a filter E9 and an imaging surface S19.

[0163] 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 convex, 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 concave. 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, wherein the aperture STO may be arranged at the object side surface S9 of the fifth lens E5. 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 concave. The object side surface S15 of the eighth lens E8 is convex, and the image side surface S16 is convex. The filter E9 has an object side surface S17 and an image side surface S18. Light from the object passes through each surface S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0164] In this example, the total length TTL of the zoom lens group is 24.47 mm, and half of the diagonal length ImgH of the effective pixel area on the imaging surface S19 of the zoom lens group is 2.90 mm.

[0165] Table 13 shows a basic parameter table of the zoom lens group of Example 5, wherein the units of the curvature radius, thickness / distance and focal length are all millimeters (mm).

[0166]

[0167] Table 13

[0168] In this example, continuous zooming of the zoom lens group can be achieved by changing the positions of the second lens group, the third lens group and the filter on the optical axis. In other words, the zoom lens group can be switched from a wide-angle state to a telephoto state or from a telephoto state to a wide-angle 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 between the image side surface of the second lens E2 and the object side surface of the third lens E3 on the optical axis), the spacing distance D8 between the second lens group and the third lens group on the optical axis (i.e., the spacing distance between the image side surface of the fourth lens E4 and the object side surface of the fifth lens E5 on the optical axis), the spacing distance D17 between the third lens group and the filter on the optical axis (i.e., the spacing distance between the image side surface of the eighth lens E8 and the object side surface of the filter E9 on the optical axis), and the spacing distance D19 between the filter and the imaging surface on the optical axis (i.e., the spacing distance between the image side surface of the filter E9 and the imaging surface S19 on the optical axis). The total effective focal length F, the maximum field angle FOV, and the aperture value Fno of the zoom lens group change as the zoom lens group switches from the wide-angle state to the telephoto state or from the telephoto state to the wide-angle state.

[0169] Table 14 shows a table of parameters that change with different states of the zoom lens group in Example 5, wherein the units of F, D4, D8, D17 and D19 are all millimeters (mm), and the unit of FOV is degrees (°).

[0170] F FOV Fno D4 D8 D17 D19 Wide angle state 10.17 33.3 2.63 1.18 7.63 1.37 0.18 Intermediate state 14.48 22.8 3.01 3.26 4.50 2.19 0.41 Telephoto state 26.00 12.8 4.33 3.68 0.48 5.69 0.51

[0171] Table 14

[0172] Table 15 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 5, wherein each aspherical surface shape can be defined by the formula (1) given in the above Example 1.

[0173] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 2.2354E-03 -2.5038E-03 1.6514E-03 -6.1307E-04 1.2943E-04 -1.1866E-05 -1.2421E-06 5.7220E-07 -9.1602E-08 S2 1.4014E-02 -1.9168E-02 1.3694E-02 -5.6200E-03 1.3558E-03 -1.6448E-04 -4.2969E-06 5.4171E-06 -1.0336E-06 S3 1.4014E-02 -1.9168E-02 1.3694E-02 -5.6200E-03 1.3558E-03 -1.6448E-04 -4.2969E-06 5.4171E-06 -1.0336E-06 S4 -2.5702E-04 1.0455E-03 -1.0138E-03 6.1127E-04 -2.4052E-04 6.3435E-05 -1.1280E-05 1.3174E-06 -9.0780E-08 S5 -4.4391E-03 3.3223E-04 -1.7270E-05 6.1666E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S6 -4.2229E-03 -3.3648E-04 3.5017E-05 4.1621E-07 -1.7732E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S7 -2.8302E-03 2.4813E-03 -3.4250E-03 2.0810E-03 -4.6748E-04 -1.9958E-04 1.9883E-04 -7.7897E-05 1.8477E-05 S8 -6.4002E-03 6.4520E-03 -9.7307E-03 9.5249E-03 -6.1874E-03 2.7906E-03 -9.0171E-04 2.1278E-04 -3.6964E-05 S9 -1.0480E-03 -7.3168E-05 -8.2158E-06 7.4515E-07 -1.0015E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S10 3.4297E-03 -6.6703E-04 1.3085E-04 -1.3948E-05 5.7391E-07 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 S11 -3.9679E-03 5.3539E-03 -1.2772E-02 1.9189E-02 -1.9200E-02 1.3323E-02 -6.5652E-03 2.3285E-03 -5.9619E-04 S12 -5.3769E-03 1.3323E-02 -3.9201E-02 7.3647E-02 -9.0322E-02 7.5514E-02 -4.4311E-02 1.8556E-02 -5.5729E-03 S13 -7.1772E-05 -2.8252E-02 9.5087E-02 -1.9448E-01 2.5423E-01 -2.2453E-01 1.3864E-01 -6.0992E-02 1.9262E-02 S14 -8.2932E-02 3.1550E-01 -5.5684E-01 4.9213E-01 -1.8593E-01 -4.2882E-02 8.5297E-02 -4.6253E-02 1.4359E-02 S15 -8.4043E-02 2.9077E-01 -4.9328E-01 4.0614E-01 -1.0469E-01 -1.0283E-01 1.2121E-01 -6.3199E-02 2.0339E-02 S16 -2.6316E-02 6.5790E-02 -1.2269E-01 1.3918E-01 -1.0337E-01 5.3422E-02 -1.9983E-02 5.5524E-03 -1.1613E-03

[0174] Table 15

[0175] Fig.28A , 29A 30A respectively show the axial chromatic aberration curves when the zoom lens group of Example 5 is in the wide-angle state, the intermediate state and the telephoto state, which indicate that light of different wavelengths deviates from the focal point behind the lens. Fig.28B , 29B 30A and 30B respectively show the astigmatism curves of the zoom lens group of Example 5 when it is in the wide-angle state, the intermediate state and the telephoto state, which represent the meridional image curvature and the sagittal image curvature. Fig.28C , 29C 30C respectively show the distortion curves of the zoom lens group of Example 5 when it is in the wide-angle state, the middle state and the telephoto state, which represent the distortion magnitude values ​​corresponding to different image heights. Fig.28D ,29D , 30D respectively show the magnification chromatic aberration curves when the zoom lens group of Example 5 is in the wide-angle state, the intermediate state and the telephoto state, which represent the deviation of the different image heights on the imaging surface after the light passes through the lens. 28A to 30D It can be seen that the zoom lens group provided in Example 5 can achieve good imaging quality in all states.

[0176] In summary, Examples 1 to 5 respectively satisfy the relationships shown in Table 16.

[0177]

[0178]

[0179] Table 16

[0180] 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.

[0181] 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 positive optical power comprises a first lens with optical power and a second lens with optical power arranged in sequence along the optical axis, wherein the object side surface of the first lens is convex and the image side surface is concave; the object side surface of the second lens is convex and the image side surface is concave; a second lens group with negative optical power, comprising a third lens with negative optical power and a fourth lens with optical power, which are sequentially arranged along the optical axis, wherein the object-side surface of the third lens is convex, and the image-side surface is concave; the object-side surface of the fourth lens is convex, and the image-side surface is concave; and a third lens group with positive power, comprising a fifth lens with positive power and a convex object-side surface and an image-side surface, a sixth lens with power, a seventh lens with negative power and a concave object-side surface and an eighth lens with power and a convex object-side surface, which are sequentially arranged along the optical axis, wherein the object-side surface of the sixth lens is a convex surface and the image-side surface is a concave surface; Wherein, the number of lenses having optical power in the zoom lens group is eight; The positions of the second lens group and the third lens group on the optical axis are adjustable; 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 wide-angle state to the telephoto 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 f8 of the eighth lens satisfy: 4.36≤(FT+FM+FW) / f8≤4.

89.

2. The zoom lens assembly according to claim 1, wherein: The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens and the effective focal length f4 of the fourth lens satisfy: 2.7<(f2-f1) / (f4-f3)≤5.

41.

3. The zoom lens assembly according to claim 1, wherein: The effective focal length f5 of the fifth lens, the effective focal length f6 of the sixth lens, the effective focal length f7 of the seventh lens and the effective focal length f8 of the eighth lens satisfy: -3.07≤(f5+f6) / (f7+f8)≤-2.

71.

4. The zoom lens assembly according to claim 1, wherein: The center thickness CT5 of the fifth lens on the optical axis, the center thickness CT6 of the sixth lens on the optical axis, the center thickness CT7 of the seventh lens on the optical axis, the center thickness CT8 of the eighth lens on the optical axis, and the spacing T67 between the sixth lens and the seventh lens on the optical axis satisfy: 1.8≤T67 / (CT5+CT6+CT7+CT8)≤1.

9.

5. The zoom lens assembly according to claim 1, wherein: A curvature radius R3 of the object side surface of the second lens, a curvature radius R4 of the image side surface of the second lens, a curvature radius R1 of the object side surface of the first lens, and a curvature radius R2 of the image side surface of the first lens satisfy: 1.65≤(R3+R4) / (R1+R2)<2.

0.

6. The zoom lens assembly according to claim 1, wherein: A curvature radius R5 of the object side surface of the third lens, a curvature radius R6 of the image side surface of the third lens, 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: 1.95≤(R5+R6) / (R7+R8)≤2.

50.

7. The zoom lens assembly according to claim 1, wherein: A center thickness CT1 of the first lens on the optical axis, a center thickness CT2 of the second lens on the optical axis, a center thickness CT3 of the third lens on the optical axis, and a center thickness CT4 of the fourth lens on the optical axis satisfy: 1.31≤(CT1+CT2) / (CT3+CT4)≤1.

35.

8. The zoom lens assembly according to any one of claims 2 to 7, characterized in that: The effective focal length F1 of the first lens group and the effective focal length F3 of the third lens group satisfy: 5.26≤F1 / F3≤5.

43.

9. The zoom lens assembly according to any one of claims 1 to 7, characterized in that: A distance TTL from the object side surface of the first lens to the imaging surface of the zoom lens group on the optical axis and an effective focal length F2 of the second lens group satisfy: -2.36≤TTL / F2≤-2.

32.

10. The zoom lens assembly according to any one of claims 1 to 7, characterized in that: The total effective focal length FT when the zoom lens group is in a telephoto state and the total effective focal length FW when the zoom lens group is in a wide-angle state satisfy: 2.56≤FT / FW≤2.

58.

11. The zoom lens assembly according to any one of claims 1 to 7, characterized in that: At least one of the first to eighth lenses is a glass lens; and At least one of the object-side surface of the first lens to the image-side surface of the eighth lens is an aspherical mirror surface.

Images