Lens assembly and mobile terminal

Abstract

The present invention relates to a lens assembly and a mobile terminal. The lens assembly includes: a lens group, which includes a plurality of lenses; and an image sensor located on the optical axis of the lens group and including an imaging surface. The lens assembly determines the lens parameters and aspheric coefficients of the plurality of lenses based on at least one of the following three conditional expressions: 1.16 < EFL / IMH < 1.3; 1.3 < TTL / TL < 1.7; 1.2 < EFL / TL < 1.45; where EFL is the effective focal length of the lens assembly; IMH is half of the diagonal dimension of the imaging surface of the image sensor; TL is the distance in the optical axis direction from the object side surface to the most prominent position closest to the image sensor among the object side surface and the image side surface of each lens in the lens group; and TTL is the distance from the object side surface of the lens closest to the object side in the lens group to the imaging surface of the image sensor on the optical axis. On the premise of ensuring optical performance, the lens assembly of the present invention can shorten the thickness of each lens in the lens group and the distance between the lenses, and thus can shorten the thickness of the lens body.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic devices, and particularly to a lens assembly and a mobile terminal. Background Art

[0002] With the continuous upgrading of the specifications of consumer electronic products, especially mobile electronic devices such as smart phones, the pursuit of miniaturization has never stopped. For optical imaging lenses, the most important characteristics are still imaging quality and volume.

[0003] In related technologies, to achieve the ultra-thinness of smart phones, optical imaging lenses are developing towards miniaturization. Usually, the number of lenses is reduced to compress the volume of the optical imaging lens, resulting in a decline in imaging quality. How to balance imaging quality and miniaturization of optical imaging lenses is a problem that needs to be considered. Summary of the Invention

[0004] To overcome the problems existing in related technologies, the present invention provides a lens assembly and a mobile terminal.

[0005] According to a first aspect of an embodiment of the present invention, a lens assembly is provided, including: a lens group, the lens group including a plurality of lenses; a photosensitive element, located on the optical axis of the lens group and including an imaging surface; wherein, the lens assembly determines the lens parameters and the aspherical coefficients of the plurality of lenses based on at least one of the following three conditional expressions: 1.16 < EFL / IMH < 1.3; 1.3 < TTL / TL < 1.7; 1.2 < EFL / TL < 1.45; wherein, EFL is the effective focal length of the lens assembly; IMH is half of the diagonal size of the imaging surface of the photosensitive element; TL is the distance in the optical axis direction from the object side surface to the image side surface of each lens in the lens group to the most prominent position closest to the photosensitive element; TTL is the distance from the object side surface of the lens closest to the object side in the lens group to the imaging surface of the photosensitive element on the optical axis.

[0006] In one embodiment, the lens group includes eight aspherical lenses, which are, in order from the object side to the image side, 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.

[0007] In one embodiment, the lens parameters and the aspherical coefficients of each lens of the lens group are determined based on the gaps between the eight aspherical lenses and / or the thicknesses of the lenses.

[0008] In one embodiment, the gaps and thicknesses between the eight aspherical lenses satisfy the following conditions:

[0009] 1.2 < ALT / AAG < 3.0; where ALT is the total lens thickness from the first lens to the eighth lens; AAG is the sum of the seven air gaps between the first lens and the eighth lens.

[0010] In one embodiment, the thicknesses of the eight aspherical lenses satisfy the following conditional formula: 2.0 < Tmax / Tmin < 4.5;

[0011] where Tmax is the maximum thickness among the first lens to the eighth lens, and Tmin is the minimum thickness among the first lens to the eighth lens.

[0012] In one embodiment, the gaps between the eight aspherical lenses satisfy the following conditional formula:

[0013] 2.6 < Gmax / Gmin < 25.0; where Gmax is the maximum of the seven air gaps between the first lens and the eighth lens, and Gmin is the minimum of the seven air gaps between the first lens and the eighth lens.

[0014] In one embodiment, based on the central thicknesses of the eight aspherical lenses, the lens parameters and the aspherical coefficients of each lens of the lens group are determined.

[0015] In one embodiment, the central thicknesses of the eight aspherical lenses satisfy the following conditional formula:

[0016] 0.9 < (T1 + T6 + T7 + T8) / (T2 + T3 + T4 + T5) < 3; where T1 is the central thickness of the first lens, T2 is the central thickness of the second lens, T3 is the central thickness of the third lens, T4 is the central thickness of the fourth lens, T5 is the central thickness of the fifth lens, T6 is the central thickness of the sixth lens, T7 is the central thickness of the seventh lens, and T8 is the central thickness of the eighth lens.

[0017] In one embodiment, the central thicknesses of the eight aspherical lenses satisfy the following conditional formula:

[0018] 3 < (T1 + T2 + T3 + T4 + T5) / T3 < 8; where T1 is the central thickness of the first lens, T2 is the central thickness of the second lens, T3 is the central thickness of the third lens, T4 is the central thickness of the fourth lens, T5 is the central thickness of the fifth lens, T6 is the central thickness of the sixth lens, T7 is the central thickness of the seventh lens, and T8 is the central thickness of the eighth lens.

[0019] In one embodiment, the lens parameters and the aspheric coefficients of each lens of the lens group are determined based on the focal lengths of the eight aspheric lenses.

[0020] In one embodiment, the focal lengths of the eight aspheric lenses satisfy the following conditional formula:

[0021] 1.0<|f2 / f1|<4.5; wherein f1 is the focal length of the first lens of the lens assembly, and f2 is the focal length of the second lens of the lens assembly.

[0022] In one embodiment, the focal lengths of the eight aspheric lenses satisfy the following conditional formula:

[0023] 0.23<|EFL / f2|+|EFL / f3|<2.5; wherein f2 is the focal length of the second lens, and f3 is the focal length of the third lens.

[0024] In one embodiment, the lens parameters and the aspheric coefficients of each lens of the lens group are determined based on the optical axis distances of the eight aspheric lenses.

[0025] In one embodiment, the optical axis distance of the eight aspheric lenses satisfies the following conditional formula:

[0026] 1.5<(G23+G34+G56) / (G12+G45+G67+G78)<3.6;

[0027] Among them, G12 is the distance between the first lens and the second lens on the optical axis, G23 is the distance between the second lens and the third lens on the optical axis, G34 is the distance between the third lens and the fourth lens on the optical axis, G45 is the distance between the fourth lens and the fifth lens on the optical axis, G56 is the distance between the fifth lens and the sixth lens on the optical axis, G67 is the distance between the sixth lens and the seventh lens on the optical axis, and G78 is the distance between the seventh lens and the eighth lens on the optical axis.

[0028] In one embodiment, the optical axis distance of the eight aspheric lenses satisfies the following conditional formula:

[0029] 4<(G23+G34+G56+OBFL) / (G12+G45+G67+G78)<14; wherein OBFL is the distance from the image side surface of the eighth lens to the imaging surface on the optical axis.

[0030] In one embodiment, the lens parameters and the aspheric coefficients of each lens of the lens group are determined based on the following conditional formula:

[0031] 1.45 < TL / EPD < 1.90; where EPD is the entrance pupil diameter of the lens assembly.

[0032] In one embodiment, the lens parameters and the aspherical coefficients of the lenses of the lens group are determined based on the following conditional expression: 16.0 < HFOV * EPD / EFL < 19.3; where HFOV is the half field of view angle of the lens assembly.

[0033] In one embodiment, the lens parameters and the aspherical coefficients of the lenses of the lens group are determined based on the following conditional expression: 2.8 < TTL * IMH / (EPD * AP8) < 3.6; where AP8 is the maximum effective diameter radius size of the eighth lens.

[0034] In one embodiment, the lens parameters and the aspherical coefficients are determined based on the entrance pupil diameter of the lens assembly.

[0035] In one embodiment, the lens parameters and the aspherical coefficients of the lenses of the lens group are determined based on the following conditional expression: 0.95 < ALT / BFL < 1.9; where BFL is the distance from the most convex point on the image side of the eighth lens to the image plane along the optical axis direction.

[0036] In one embodiment, the lens parameters and the aspherical coefficients of the lenses of the lens group are determined based on the following conditional expression: 0.58 < CP72 / CP82 < 1.3; where CP72 is the distance from the critical point on the image side surface of the seventh lens to the optical axis, and CP82 is the distance from the critical point on the image side surface of the eighth lens to the optical axis.

[0037] In one embodiment, the lens group can move along the optical axis direction; where, when the lens assembly is in the working state, the distance between the lens group and the imaging surface of the photosensitive element is a first distance; when the lens assembly is in the non - working state, the distance between the lens group and the imaging surface of the photosensitive element is a second distance, and the first distance is greater than the second distance.

[0038] In one embodiment, the lens assembly includes: a driving member, which is arranged in the terminal body and drives the lens body to move.

[0039] In one embodiment, the driving member includes a driving motor arranged in the terminal body, a gear transmission - connected to the driving motor, and a rack meshing with the gear, and the rack is connected to the lens body.

[0040] In one embodiment, the driving member includes a driving motor disposed in the terminal body and a screw rod drivingly connected to the driving motor, the screw rod is threadedly connected to the lens body, and the driving motor drives the screw rod to rotate, thereby driving the lens body to move linearly.

[0041] In one embodiment, the driving member includes a first electromagnetic component fixed in the terminal body, and a second electromagnetic component fixed on the outer wall of the lens body. The first electromagnetic component and the second electromagnetic component are connected to the control circuit of the terminal, which controls the first electromagnetic component and the second electromagnetic component to change their magnetism so as to attract or repel each other, thereby moving the lens body.

[0042] In one embodiment, a color filter is arranged between the photosensitive element and the lens group, and the color filter can be moved closer to or away from the photosensitive element along the optical axis direction; wherein, when the lens assembly is in a working state, the distance between the color filter and the imaging surface of the photosensitive element is a third distance; when the lens assembly is in a non-working state, the distance between the color filter and the imaging surface of the photosensitive element is a fourth distance, and the third distance is greater than the fourth distance.

[0043] According to a second aspect of the embodiments of the present invention, there is provided a mobile terminal, comprising the lens assembly described in any one of the embodiments of the first aspect.

[0044] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0045] The lens assembly disclosed in the present invention can shorten the thickness of each lens in the lens group and the distance between lenses while ensuring the optical performance, thereby shortening the thickness of the lens body.

[0046] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0048] Figure 1 is a structural schematic diagram of a lens assembly according to an exemplary embodiment of the present disclosure.

[0049] Figure 2 is a schematic diagram showing a lens assembly in a working state according to an exemplary embodiment of the present disclosure.

[0050] Figure 3 is a schematic diagram showing a lens assembly in a non-working state according to an exemplary embodiment of the present disclosure.

[0051] Figure 4A is a schematic structural diagram of a lens assembly of a first embodiment according to an exemplary embodiment of the present disclosure.

[0052] Figure 4B According to an exemplary embodiment of the present disclosure Figure 4A Spherical aberration, astigmatism and distortion curves.

[0053] Figure 5A is a schematic structural diagram of a lens assembly of a second embodiment according to an exemplary embodiment of the present disclosure.

[0054] Figure 5B According to an exemplary embodiment of the present disclosure Figure 5A Spherical aberration, astigmatism and distortion curves.

[0055] Fig. 6A is a schematic structural diagram of a lens assembly according to a third embodiment of the present disclosure.

[0056] Figure 6B According to an exemplary embodiment of the present disclosure Fig. 6A Spherical aberration, astigmatism and distortion curves.

[0057] Fig. 7A is a schematic structural diagram of a lens assembly according to a fourth embodiment of the present disclosure.

[0058] Figure 7B According to an exemplary embodiment of the present disclosure Fig. 7A Spherical aberration, astigmatism and distortion curves.

[0059] Fig. 8A is a schematic structural diagram of a lens assembly of a fifth embodiment according to an exemplary embodiment of the present disclosure.

[0060] Figure 8B According to an exemplary embodiment of the present disclosure Fig. 8A Spherical aberration, astigmatism and distortion curves.

[0061] Fig. 9A is a schematic structural diagram of a lens assembly according to a sixth embodiment of the present disclosure.

[0062] Fig. 9B According to an exemplary embodiment of the present disclosure Fig. 9A Spherical aberration, astigmatism and distortion curves.

[0063] Fig. 10A is a schematic structural diagram of a lens assembly according to a seventh embodiment of the present disclosure.

[0064] Fig. 10B According to an exemplary embodiment of the present disclosure Fig. 10A Spherical aberration, astigmatism and distortion curves.

[0065] Fig.11A is a schematic structural diagram of a lens assembly according to an eighth embodiment of the present disclosure.

[0066] Fig. 11B According to an exemplary embodiment of the present disclosure Fig.11A Spherical aberration, astigmatism and distortion curves.

[0067] Fig. 12A is a schematic structural diagram of a lens assembly of a ninth embodiment according to an exemplary embodiment of the present disclosure.

[0068] Fig. 12B According to an exemplary embodiment of the present disclosure Fig. 12A Spherical aberration, astigmatism and distortion curves.

[0069] Fig.13A is a schematic structural diagram of a lens assembly according to a tenth embodiment of the present disclosure.

[0070] Fig. 13B According to an exemplary embodiment of the present disclosure Fig.13A Spherical aberration, astigmatism and distortion curves.

[0071] Fig.14A 4 is a schematic structural diagram of a lens assembly according to an eleventh embodiment of the present disclosure.

[0072] Fig. 14B According to an exemplary embodiment of the present disclosure Fig.14A Spherical aberration, astigmatism and distortion curves

[0073] Fig.15A 4 is a schematic structural diagram of a lens assembly according to a twelfth embodiment of the present disclosure.

[0074] Fig. 15B According to an exemplary embodiment of the present disclosure Fig.15A Spherical aberration, astigmatism and distortion curves.

[0075] Fig.16A 4 is a schematic structural diagram of a lens assembly according to a thirteenth embodiment of the present disclosure.

[0076] Fig. 16B According to an exemplary embodiment of the present disclosure Fig.16A Spherical aberration, astigmatism and distortion curves.

[0077] Fig.17A 4 is a schematic structural diagram of a lens assembly according to a fourteenth embodiment of the present disclosure.

[0078] Fig. 17B According to an exemplary embodiment of the present disclosure Fig.17A Spherical aberration, astigmatism and distortion curves.

[0079] Fig.18A 4 is a schematic structural diagram of a lens assembly according to a fifteenth embodiment of the present disclosure.

[0080] Fig.18B According to an exemplary embodiment of the present disclosure Fig.18A Spherical aberration, astigmatism and distortion curves.

[0081] Fig.19A 4 is a schematic structural diagram of a lens assembly according to a sixteenth embodiment of the present disclosure.

[0082] Fig.19B According to an exemplary embodiment of the present disclosure Fig.19A Spherical aberration, astigmatism and distortion curves.

[0083] Fig. 20 It is a schematic diagram of the structure of a mobile terminal according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0084] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0085] The embodiment of the present disclosure provides a lens assembly, which can be applied to a mobile terminal, which can be a portable electronic device such as a smart phone, a tablet computer, or a laptop computer.

[0086] Figure 1 FIG. 1 is a schematic diagram showing the structure of a lens assembly according to an exemplary embodiment of the present disclosure. Figure 1 As shown, the lens assembly 1 includes a lens group 10 and a photosensitive element 200 .

[0087] The lens group 10 includes a plurality of lenses, and the photosensitive element 200 is located on the optical axis of the lens group 10 and includes an imaging surface; wherein, the lens assembly 1 determines the lens parameters and the aspherical coefficients of the respective lenses of the lens group based on at least one of the following three conditional expressions: 1.16 < EFL / IMH < 1.3; 1.3 < TTL / TL < 1.7; 1.2 < EFL / TL < 1.45; that is, any one or more of the three conditional expressions are used to determine the lens parameters and the aspherical coefficients of the respective lenses of the lens group.

[0088] Wherein, EFL is the effective focal length of the lens assembly 1; IMH is half of the diagonal dimension of the imaging surface of the photosensitive element 200; TL is the distance along the optical axis from the object side surface to the most prominent position closest to the photosensitive element 200 on the image side surface of each lens in the lens group 10; TTL is the distance from the object side surface of the lens closest to the object side in the lens group 10 to the imaging surface of the photosensitive element 200 on the optical axis. The photosensitive element 200 is a photosensitive chip.

[0089] The present disclosure determines the parameters of the lens and the aspherical coefficients of each lens through the above conditional expressions. On the premise of ensuring optical performance, the thickness of each lens in the lens group 10 and the distance between the lenses can be shortened, and further the thickness of the lens body can be shortened, which is beneficial to the thinning of the mobile terminal when applied to a mobile terminal (such as a mobile phone). In addition, since the overall thickness of the lens group 10 is reduced, the area of the light from the object to be photographed projected onto the surface of the photosensitive element 200 after being refracted and adjusted by the lenses in the lens group 10 is increased, and thus the photosensitive surface size of the photosensitive element 200 can be increased, resulting in higher imaging quality.

[0090] In an embodiment, the lens group 10 includes eight aspherical lenses, which are, in order from the object side to the image side, a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, a seventh lens 170, and an eighth lens 180. Wherein, each lens includes an object side surface and an image side surface, that is, the first lens 110 includes a first object side surface 111 and a first image side surface 112; the second lens 120 includes a second object side surface 121 and a second image side surface 122; the third lens 130 includes a third object side surface 131 and a third image side surface 132; the fourth lens 140 includes a fourth object side surface 141 and a fourth image side surface 142; the fifth lens 150 includes a fifth object side surface 151 and a fifth image side surface 152; the sixth lens 160 includes a sixth object side surface 161 and a sixth image side surface 162; the seventh lens 170 includes a seventh object side surface 171 and a seventh image side surface 172; the eighth lens 180 includes an eighth object side surface 181 and an eighth image side surface 182.

[0091] The materials of the eight aspherical lenses are all plastic materials, which can form high-precision aspherical surfaces. The aspherical surface has more control variables compared to the spherical surface, which is used to reduce aberration, and thus the number of lenses required for the traditional spherical surface can be reduced. Therefore, the overall optical length can be effectively reduced.

[0092] Furthermore, in the lens assembly 1 of the present disclosure, among the first lens 110 to the eighth lens 180, all the object sides 111, 121, 131, 141, 151, 161, 171, 181 and the image sides 112, 122, 132, 142, 152, 162, 172, 182 are a total of 16 aspherical surfaces. This aspherical surface is a Qbfs type, and its surface formula is defined by the following formula:

[0093]

[0094] where z represents the depth of the aspherical surface (the vertical distance between a point on the aspherical surface at a distance Y from the optical axis and the tangent plane at the vertex of the aspherical surface on the optical axis); r represents the distance of a point on the aspherical surface from the optical axis; k represents the conic constant; r n represents the normalized curvature; u represents r / r n ; a m represents the m-th order aspherical coefficient; Q m represents the m-th order Qbfs polynomial. The advantage of using the Qbfs polynomial to represent the aspherical surface is that its surface structure is more stable, there are fewer mutation points, and the light is less likely to show anomalies.

[0095] In some embodiments, the lens assembly 1 determines the lens parameters and the aspherical coefficients of the lenses in the lens group based on the gaps between the eight aspherical lenses and / or the thicknesses of the respective lenses.

[0096] For example, the gaps and thicknesses between the eight aspherical lenses satisfy the following conditions: 1.2 < ALT / AAG < 3.0; where ALT is the total thickness of the lenses from the first lens 110 to the eighth lens 180; AAG is the sum of the seven air gaps between the first lens 110 and the eighth lens 180. And / or,

[0097] The thicknesses of the eight aspherical lenses satisfy the following conditional formula: 2.0 < Tmax / Tmin < 4.5; where Tmax is the maximum value of the thicknesses of the lenses from the first lens 110 to the eighth lens 180, and Tmin is the minimum value of the thicknesses of the lenses from the first lens 110 to the eighth lens 180. And / or,

[0098] The gaps between the eight aspherical lenses satisfy the following conditional expression: 2.6 < Gmax / Gmin < 25.0; where Gmax is the maximum value of the seven air gaps between the first lens 110 and the eighth lens 180, and Gmin is the minimum value of the seven air gaps between the first lens 110 and the eighth lens 180.

[0099] In some embodiments, the lens assembly 1 determines the lens parameters and the aspherical coefficients of the respective lenses of the lens group based on the central thicknesses of the eight aspherical lenses.

[0100] For example, the central thicknesses of the eight aspherical lenses satisfy the following conditional expression:

[0101] 0.9 < (T1 + T6 + T7 + T8) / (T2 + T3 + T4 + T5) < 3; where T1 is the central thickness of the first lens 110, T2 is the central thickness of the second lens 120, T3 is the central thickness of the third lens 130, T4 is the central thickness of the fourth lens 140, T5 is the central thickness of the fifth lens 150, T6 is the central thickness of the sixth lens 160, T7 is the central thickness of the seventh lens 170, and T8 is the central thickness of the eighth lens 180. And / or,

[0102] The central thicknesses of the eight aspherical lenses satisfy the following conditional expression:

[0103] 3 < (T1 + T2 + T3 + T4 + T5) / T3 < 8; where T1 is the central thickness of the first lens 110, T2 is the central thickness of the second lens 120, T3 is the central thickness of the third lens 130, T4 is the central thickness of the fourth lens 140, T5 is the central thickness of the fifth lens 150, T6 is the central thickness of the sixth lens 160, T7 is the central thickness of the seventh lens 170, and T8 is the central thickness of the eighth lens 180.

[0104] In some embodiments, the lens parameters and the spherical coefficients of the respective lenses of the lens group are determined based on the focal lengths of the eight aspherical lenses.

[0105] For example, the focal lengths of the eight aspherical lenses satisfy the following conditional expression: 1.0 < |f2 / f1| < 4.5; where f1 is the focal length of the first lens 110 of the lens assembly 1, and f2 is the focal length of the second lens 120 of the lens assembly.

[0106] The focal lengths of the eight aspherical lenses satisfy the following conditional expression: 0.23 < |EFL / f2| + |EFL / f3| < 2.5. Where f2 is the focal length of the second lens, and f3 is the focal length of the third lens.

[0107] In some embodiments, the lens parameters and the spherical coefficients of the respective lenses of the lens group are determined based on the central distances between adjacent lenses.

[0108] For example, the center distances of the eight aspherical lenses satisfy the following conditional expressions:

[0109] 1.5 < (G23 + G34 + G56) / (G12 + G45 + G67 + G78) < 3.6; where G12 is the distance between the first lens 110 and the second lens 120 on the optical axis, G23 is the distance between the second lens 120 and the third lens 130 on the optical axis, G34 is the distance between the third lens 130 and the fourth lens 140 on the optical axis, G45 is the distance between the fourth lens 140 and the fifth lens 150 on the optical axis, G56 is the distance between the fifth lens 150 and the sixth lens 160 on the optical axis, G67 is the distance between the sixth lens 160 and the seventh lens 170 on the optical axis, and G78 is the distance between the seventh lens 170 and the eighth lens 180 on the optical axis.

[0110] The center distances of the eight aspherical lenses satisfy the following conditional expressions:

[0111] 4 < (G23 + G34 + G56 + OBFL) / (G12 + G45 + G67 + G78) < 14; where OBFL is the distance from the image side of the eighth lens 180 to the image plane on the optical axis.

[0112] In one embodiment, based on the entrance pupil diameter of the lens assembly, the lens parameters and the aspherical coefficients are determined

[0113] For example, the entrance pupil diameter satisfies the following conditional expressions:

[0114] 1.45 < TL / EPD < 1.90; where EPD is the entrance pupil diameter of the lens assembly 1.

[0115] The entrance pupil diameter satisfies the following conditional expressions:

[0116] 16.0 < HFOV * EPD / EFL < 19.3; where HFOV is the half field of view angle of the lens assembly 1.

[0117] The entrance pupil diameter satisfies the following conditional expressions: 2.8 < TTL * IMH / (EPD * AP8) < 3.6; where AP8 is the maximum effective diameter radius size of the eighth lens 180.

[0118] In one embodiment, based on the following conditional expressions, the lens parameters and the aspherical coefficients of each lens of the lens group are determined:

[0119] 0.95 < ALT / BFL < 1.9; where BFL is the distance from the most convex point of the image side of the eighth lens 180 to the image plane along the optical axis.

[0120] In one embodiment, the lens parameters and the aspheric coefficients of each lens of the lens group are determined based on the following conditional expressions:

[0121] 0.58 < CP72 / CP82 < 1.3; where CP72 is the distance from the critical point of the image side surface of the seventh lens 170 to the optical axis, and CP82 is the distance from the critical point of the image side surface of the eighth lens 180 to the optical axis.

[0122] Based on the conditional expressions of the above embodiments, the parameters of the lens assemblies of multiple embodiments of the present disclosure can be determined, including the aspheric lens coefficients and the aspheric coefficients. In the following embodiments, 100 represents the entrance pupil of the optical imaging system, that is, the aperture. A1 - A30 are the 1st - 30th order aspheric coefficients of each surface, K represents the conic surface coefficient in the aspheric curve equation, NR represents the refractive index, and E represents the scientific notation symbol.

[0123] Embodiment 1: Figure 4A is a schematic structural diagram of a lens assembly according to a first embodiment shown in an exemplary embodiment of the present disclosure. Figure 4B is shown according to an exemplary embodiment of the present disclosure Figure 4A spherical aberration, astigmatism and distortion curve graphs. Table 1 - 1 is the aspheric lens coefficient of the first embodiment shown according to an exemplary embodiment of the present disclosure. Table 1 - 2 is the aspheric coefficient of the first embodiment shown according to an exemplary embodiment of the present disclosure.

[0124] As Figure 4A and 4B , through the conditional expressions of the above embodiments, the aspheric lens coefficients (as shown in Table 1 - 1) and the aspheric coefficients (as shown in Table 1 - 2) of this embodiment can be determined.

[0125] Figure 4B From left to right are Figure 4A spherical aberration, astigmatism and distortion curve graphs, and through Figure 4B it can be seen that the longitudinal spherical aberration, astigmatic aberration, field curvature aberration and distortion of this embodiment all meet the usage specifications.

[0126] Table 1 - 1

[0127]

[0128]

[0129] Table 1 - 2

[0130]

[0131]

[0132] Embodiment 2: Figure 5Ais a schematic structural diagram of a lens assembly of a second embodiment according to an exemplary embodiment of the present disclosure. Figure 5B According to an exemplary embodiment of the present disclosure Figure 5A Table 2-1 shows the aspheric lens coefficients of the second embodiment according to an exemplary embodiment of the present disclosure. Table 2-2 shows the aspheric coefficients of the second embodiment according to an exemplary embodiment of the present disclosure.

[0133] like Figure 5A and 5B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 2-1) and the aspheric coefficient (as shown in Table 2-2) of the lens assembly of this embodiment can be determined.

[0134] Figure 5B From left to right: Figure 5A Spherical aberration, astigmatism and distortion curves, through Figure 5B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0135] Table 2-1

[0136]

[0137] Table 2-2

[0138]

[0139]

[0140] Embodiment 3: Fig. 6A is a schematic structural diagram of a lens assembly of a third embodiment according to an exemplary embodiment of the present disclosure. Figure 6B According to an exemplary embodiment of the present disclosure Fig. 6A Table 3-1 shows the aspheric lens coefficients of the third embodiment according to an exemplary embodiment of the present disclosure. Table 3-2 shows the aspheric coefficients of the third embodiment according to an exemplary embodiment of the present disclosure.

[0141] like Fig. 6A and 6B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 3-1) and the aspheric coefficient (as shown in Table 3-2) of the lens assembly of this embodiment can be determined.

[0142] Figure 6B From left to right: Fig. 6A Spherical aberration, astigmatism and distortion curves, through Figure 6B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0143] Table 3-1

[0144]

[0145] Table 3-2

[0146]

[0147]

[0148] Embodiment 4: Fig. 7A is a schematic structural diagram of a lens assembly according to a fourth embodiment of the present disclosure. Figure 7B According to an exemplary embodiment of the present disclosure Fig. 7A Table 4-1 shows the aspheric lens coefficients of the fourth embodiment according to an exemplary embodiment of the present disclosure. Table 4-2 shows the aspheric coefficients of the fourth embodiment according to an exemplary embodiment of the present disclosure.

[0149] like Fig. 7A and 7B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 4-1) and the aspheric coefficient (as shown in Table 4-2) of the lens assembly of this embodiment can be determined.

[0150] Figure 7B From left to right: Fig. 7A Spherical aberration, astigmatism and distortion curves, through Figure 7B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0151] Table 4-1

[0152]

[0153]

[0154] Table 4-2

[0155]

[0156]

[0157] Embodiment 5: Fig. 8A is a schematic structural diagram of a lens assembly according to a fifth embodiment of the present disclosure. Figure 8B According to an exemplary embodiment of the present disclosure Fig. 8ATable 4-1 shows the aspheric lens coefficients of the fifth embodiment according to an exemplary embodiment of the present disclosure. Table 4-2 shows the aspheric coefficients of the fifth embodiment according to an exemplary embodiment of the present disclosure.

[0158] like Fig. 8A and 8B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 5-1) and the aspheric coefficient (as shown in Table 5-2) of the lens assembly of this embodiment can be determined.

[0159] Figure 8B From left to right: Fig. 8A Spherical aberration, astigmatism and distortion curves, through Figure 8B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0160] Table 5-1

[0161]

[0162]

[0163] Table 5-2

[0164]

[0165]

[0166] Embodiment 6: Fig. 9A is a schematic structural diagram of a lens assembly according to a sixth embodiment of the present disclosure. Fig. 9B According to an exemplary embodiment of the present disclosure Fig. 9A Table 6-1 shows the aspheric lens coefficients of the sixth embodiment according to an exemplary embodiment of the present disclosure. Table 6-2 shows the aspheric coefficients of the sixth embodiment according to an exemplary embodiment of the present disclosure.

[0167] like Fig. 9A and 9B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 6-1) and the aspheric coefficient (as shown in Table 6-2) of the lens assembly of this embodiment can be determined.

[0168] Fig. 9B From left to right: Fig. 9A Spherical aberration, astigmatism and distortion curves, through Fig. 9B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0169] Table 6-1

[0170]

[0171] Table 6-2

[0172]

[0173]

[0174] Embodiment 7: Fig. 10A is a schematic structural diagram of a lens assembly according to a seventh embodiment of the present disclosure. Fig. 10B According to an exemplary embodiment of the present disclosure Fig. 10A Table 7-1 shows the aspheric lens coefficients of the seventh embodiment according to an exemplary embodiment of the present disclosure. Table 7-2 shows the aspheric coefficients of the seventh embodiment according to an exemplary embodiment of the present disclosure.

[0175] like Fig. 10A and 10B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 7-1) and the aspheric coefficient (as shown in Table 7-2) of the lens assembly of this embodiment can be determined.

[0176] Fig. 10B From left to right: Fig. 10A Spherical aberration, astigmatism and distortion curves, through Fig. 10B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0177] Table 7-1

[0178]

[0179] Table 7-2

[0180]

[0181]

[0182] Embodiment 8: Fig.11A is a schematic structural diagram of a lens assembly according to an eighth embodiment of the present disclosure. Fig. 11B According to an exemplary embodiment of the present disclosure Fig.11A Table 8-1 shows the aspheric lens coefficients of the eighth embodiment according to an exemplary embodiment of the present disclosure. Table 8-2 shows the aspheric coefficients of the eighth embodiment according to an exemplary embodiment of the present disclosure.

[0183] like Fig.11A and 11BThrough the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 8-1) and the aspheric coefficient (as shown in Table 8-2) of the lens assembly of this embodiment can be determined.

[0184] Fig. 11B From left to right: Fig.11A Spherical aberration, astigmatism and distortion curves, through Fig. 11B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0185] Table 8-1

[0186]

[0187]

[0188] Table 8-2

[0189]

[0190]

[0191] Embodiment 9: Fig. 12A is a schematic structural diagram of a lens assembly of a ninth embodiment according to an exemplary embodiment of the present disclosure. Fig. 12B According to an exemplary embodiment of the present disclosure Fig. 12A Table 9-1 shows the aspheric lens coefficients of the ninth embodiment according to an exemplary embodiment of the present disclosure. Table 9-2 shows the aspheric coefficients of the ninth embodiment according to an exemplary embodiment of the present disclosure.

[0192] like Fig. 12A and 12B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 9-1) and the aspheric coefficient (as shown in Table 9-2) of the lens assembly of this embodiment can be determined.

[0193] Fig. 12B From left to right: Fig. 12A Spherical aberration, astigmatism and distortion curves, through Fig. 12B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0194] Table 9-1

[0195]

[0196]

[0197] Table 9-2

[0198]

[0199]

[0200] Embodiment 10: Fig.13A is a schematic structural diagram of a lens assembly according to a tenth embodiment of the present disclosure. Fig. 13B According to an exemplary embodiment of the present disclosure Fig.13A Table 10-1 shows the aspheric lens coefficients of the tenth embodiment according to an exemplary embodiment of the present disclosure. Table 10-2 shows the aspheric coefficients of the tenth embodiment according to an exemplary embodiment of the present disclosure.

[0201] like Fig.13A and 13B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 10-1) and the aspheric coefficient (as shown in Table 10-2) of the lens assembly of this embodiment can be determined.

[0202] Fig. 13B From left to right: Fig.13A Spherical aberration, astigmatism and distortion curves, through Fig. 13B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0203] Table 10-1

[0204]

[0205] Table 10-2

[0206]

[0207]

[0208] Embodiment 11: Fig.14A 4 is a schematic structural diagram of a lens assembly according to an eleventh embodiment of the present disclosure. Fig. 14B According to an exemplary embodiment of the present disclosure Fig.14A Table 11-1 shows the aspheric lens coefficients of the eleventh embodiment according to an exemplary embodiment of the present disclosure. Table 11-2 shows the aspheric coefficients of the eleventh embodiment according to an exemplary embodiment of the present disclosure.

[0209] like Fig.14A and 14B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 11-1) and the aspheric coefficient (as shown in Table 11-2) of the lens assembly of this embodiment can be determined.

[0210] Fig. 14BFrom left to right: Fig.14A Spherical aberration, astigmatism and distortion curves, through Fig. 14B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0211] Table 11-1

[0212]

[0213] Table 11-2

[0214]

[0215]

[0216] Embodiment 12: Fig.15A 4 is a schematic structural diagram of a lens assembly according to a twelfth embodiment of the present disclosure. Fig. 15B According to an exemplary embodiment of the present disclosure Fig.15A Table 12-1 shows the aspheric lens coefficients of the twelfth embodiment according to an exemplary embodiment of the present disclosure. Table 12-2 shows the aspheric coefficients of the twelfth embodiment according to an exemplary embodiment of the present disclosure.

[0217] like Fig.15A and 15B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 12-1) and the aspheric coefficient (as shown in Table 12-2) of the lens assembly of this embodiment can be determined.

[0218] Fig. 15B From left to right: Fig.15A Spherical aberration, astigmatism and distortion curves, through Fig. 15B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0219] Table 12-1

[0220]

[0221]

[0222] Table 12-2

[0223]

[0224]

[0225] Embodiment 13: Fig.16A 4 is a schematic structural diagram of a lens assembly according to a thirteenth embodiment of the present disclosure. Fig. 16B According to an exemplary embodiment of the present disclosure Fig.16A Table 13-1 shows the aspheric lens coefficients of the thirteenth embodiment according to an exemplary embodiment of the present disclosure. Table 13-2 shows the aspheric coefficients of the thirteenth embodiment according to an exemplary embodiment of the present disclosure.

[0226] like Fig.16A and 16B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 13-1) and the aspheric coefficient (as shown in Table 13-2) of the lens assembly of this embodiment can be determined.

[0227] Fig. 16B From left to right: Fig.16A Spherical aberration, astigmatism and distortion curves, through Fig. 16B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0228] Table 13-1

[0229]

[0230]

[0231] Table 13-2

[0232]

[0233]

[0234] Embodiment 14: Fig.17A 4 is a schematic structural diagram of a lens assembly according to a fourteenth embodiment of the present disclosure. Fig. 17B According to an exemplary embodiment of the present disclosure Fig.17A Table 14-1 shows the aspheric lens coefficients of the fourteenth embodiment according to an exemplary embodiment of the present disclosure. Table 14-2 shows the aspheric coefficients of the fourteenth embodiment according to an exemplary embodiment of the present disclosure.

[0235] like Fig.17A and 17B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 14-1) and the aspheric coefficient (as shown in Table 14-2) of the lens assembly of this embodiment can be determined.

[0236] Fig. 17B From left to right: Fig.17A Spherical aberration, astigmatism and distortion curves, through Fig. 17BIt can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0237] Table 14-1

[0238]

[0239] Table 14-2

[0240]

[0241]

[0242] Embodiment 15: Fig.18A 4 is a schematic structural diagram of a lens assembly according to a fifteenth embodiment of the present disclosure. Fig.18B According to an exemplary embodiment of the present disclosure Fig.18A Table 15-1 shows the aspheric lens coefficients of the fifteenth embodiment according to an exemplary embodiment of the present disclosure. Table 15-2 shows the aspheric coefficients of the fifteenth embodiment according to an exemplary embodiment of the present disclosure.

[0243] like Fig.18A and 18B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 15-1) and the aspheric coefficient (as shown in Table 15-2) of the lens assembly of this embodiment can be determined.

[0244] Fig.18B From left to right: Fig.18A Spherical aberration, astigmatism and distortion curves, through Fig.18B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0245] Table 15-1

[0246]

[0247]

[0248] Table 15-2

[0249]

[0250]

[0251] Embodiment 16: Fig.19A 4 is a schematic structural diagram of a lens assembly according to a sixteenth embodiment of the present disclosure. Fig.19B According to an exemplary embodiment of the present disclosure Fig.19ATable 16-1 shows the aspheric lens coefficients of the sixteenth embodiment according to an exemplary embodiment of the present disclosure. Table 16-2 shows the aspheric coefficients of the sixteenth embodiment according to an exemplary embodiment of the present disclosure.

[0252] like Fig.19A and 19B Through the conditional formula of the above embodiment, the aspheric lens coefficient (as shown in Table 16-1) and the aspheric coefficient (as shown in Table 16-2) of the lens assembly of this embodiment can be determined.

[0253] Fig.19B From left to right: Fig.19A Spherical aberration, astigmatism and distortion curves, through Fig.19B It can be seen that the longitudinal spherical aberration, astigmatism, field curvature and distortion of this embodiment all meet the usage specifications.

[0254] Table 16-1

[0255]

[0256]

[0257] Table 16-2

[0258]

[0259]

[0260] In some embodiments, Table 17 shows the specific values ​​of each parameter in the above-mentioned embodiments 1 to 16. As shown in Table 17, when each embodiment satisfies the following corresponding parameters, the photosensitive surface size of the photosensitive element 300 of the embodiment of the present disclosure is 14.29, that is, 1 / 1.12” inches.

[0261] Table 17

[0262]

[0263]

[0264]

[0265]

[0266] like Figures 1 to 3 As shown, in some embodiments, the lens group 10 can move along the optical axis direction; wherein, when the lens assembly 1 is in the working state, the distance between the lens group 10 and the imaging surface of the photosensitive element 200 is a first distance L1 ( Figure 2When the lens assembly 1 is not in operation, the distance between the lens group 10 and the imaging surface of the photosensitive element 200 is the second distance L2 ( Figure 3 As shown in FIG. 1 , the first distance L1 is greater than the second distance L2. Specifically, the lens assembly 1 includes a lens body, which is movably disposed in the terminal body, and the lens group 10 is disposed in the lens body; wherein, when the lens assembly is in a working state, the lens body moves to the outside of the terminal body, driving the lens group away from the photosensitive element; when the lens assembly is in a non-working state, the lens body moves to the outside of the terminal body, driving the lens group close to the photosensitive element.

[0267] A through hole is provided on the rear shell of the terminal body for the lens body to pass through, and the lens body can pass through the through hole to move to the inside and outside of the terminal body in the thickness direction of the terminal body. When in use, the lens body moves through the through hole to the outside of the terminal body, and at the same time drives the lens group 10 inside the lens body away from the photosensitive element 200 to perform a mobile focus. After the focus is completed, the light from the object to be photographed is refracted and adjusted by the lens in the lens group 10, and then projected onto the surface of the photosensitive element 200. The photosensitive element 200 converts the light information into digital information, which is then processed by the internal processor of the smartphone and presented on the screen. When not in use, the lens body moves to the inside of the terminal body, driving the lens group 10 inside the lens body close to the photosensitive element 200 to shorten the length of the lens body.

[0268] The disclosed embodiment can further shorten the space occupied by the lens body in the thickness direction of the terminal body through the movable lens body, which is conducive to the thinning of the mobile terminal and does not need to change the number of the original lens group 10 to ensure the optical performance.

[0269] In one embodiment, the lens assembly 1 further comprises a driving member for driving the lens group to move. Specifically, the driving member is disposed in the terminal body to drive the lens body to move.

[0270] The driving component may include a driving motor arranged on the middle frame of the terminal body, a gear connected to the driving motor and a rack meshing with the gear. The rotation of the driving motor drives the gear to rotate, and through the rack transmission, the rotational motion of the driving motor is converted into linear motion to drive the lens body to move, so as to make the lens group move away from or close to the photosensitive element.

[0271] In another embodiment, the driving member includes a driving motor disposed in the terminal body and a screw rod drivingly connected to the driving motor, the screw rod is threadedly connected to the lens body, the driving motor drives the screw rod to rotate, and drives the lens body to move inside or outside the terminal body.

[0272] In another embodiment, the driving member includes a first electromagnetic component fixed in the terminal body, and a second electromagnetic component fixed on the outer wall of the lens body. The first electromagnetic component and the second electromagnetic component are connected to the control circuit of the terminal, which controls the first electromagnetic component and the second electromagnetic component to change their magnetism so as to attract or repel each other, thereby moving the lens body.

[0273] In some embodiments, a color filter 190 is disposed between the photosensitive element 200 and the lens assembly 10, and the color filter 190 can move closer to or farther from the photosensitive element along the optical axis. When the lens assembly 1 is in working state, the distance between the color filter 190 and the imaging surface of the photosensitive element 200 is a third distance L3 ( Figure 3 When the lens assembly 1 is not in operation, the distance between the color filter 190 and the imaging surface of the photosensitive element is a fourth distance L4 (shown in FIG. 4 ), and the third distance L3 is greater than the fourth distance L4, so that when the lens body approaches or moves away from the photosensitive element, a greater movement can be obtained, which can further reduce the size of the lens body.

[0274] Fig. 20 It is a schematic diagram of the structure of a mobile terminal according to an exemplary embodiment of the present disclosure.

[0275] like Fig. 20 As shown, according to another aspect of the present disclosure, a mobile terminal 2 is provided, which includes the lens assembly 1 described in any embodiment of the first aspect above.

[0276] The mobile terminal 2 includes a terminal body 201 , and the lens assembly 1 is disposed on the terminal body 201 .

[0277] By providing the lens assembly 1 of the present invention, the mobile terminal 2 of the present invention can be made thinner and can obtain a clearer photographic effect, thereby improving the user experience.

[0278] It is to be understood that in the present invention, "plurality" refers to two or more than two, and other quantifiers are similar. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The singular forms "a", "the" and "the" are also intended to include plural forms, unless the context clearly indicates other meanings.

[0279] It is further understood that the terms "first", "second", etc. are used to describe various information, but such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other, and do not indicate a specific order or degree of importance. In fact, the expressions "first", "second", etc. can be used interchangeably. For example, without departing from the scope of the present invention, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information.

[0280] It will be further understood that the terms “center”, “longitudinal”, “lateral”, “front”, “back”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation.

[0281] It can be further understood that, unless otherwise specified, “connection” includes a direct connection without other components between the two, and also includes an indirect connection with other components between the two.

[0282] It is further understood that, although the operations are described in a specific order in the accompanying drawings in the embodiments of the present invention, it should not be understood as requiring the operations to be performed in the specific order or serial order shown, or requiring the execution of all the operations shown to obtain the desired results. In certain environments, multitasking and parallel processing may be advantageous.

[0283] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0284] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A lens assembly, characterized in that: Comprising: A lens group, the lens group includes eight lenses, and the eight lenses are, in order from the object side to the image side, 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; An image sensor, located on the optical axis of the lens group, including an imaging surface; Wherein, based on the conditional formula 0.95 < ALT / BFL < 1.9 and at least one of the following three conditional formulas, the lens parameters and aspherical coefficients of the eight lenses are determined: 1.16 < EFL / IMH < 1.3; 1.3 < TTL / TL < 1.7; 1.2 < EFL / TL < 1.45; Wherein, EFL is the effective focal length of the lens assembly; IMH is half of the diagonal size of the imaging surface of the image sensor; TL is the distance from the object side surface to the image side surface of each lens in the lens group, along the optical axis direction, to the most prominent position closest to the image sensor; TTL is the distance from the object side surface of the lens closest to the object side in the lens group to the imaging surface of the image sensor on the optical axis; ALT is the total thickness of the lenses from the first lens to the eighth lens; BFL is the distance from the most convex point of the image side surface of the eighth lens to the imaging surface along the optical axis direction.

2. The lens assembly according to claim 1, wherein The lens is an aspherical lens.

3. The lens assembly according to claim 2, wherein Based on the gaps between the lenses and / or the thicknesses of the respective lenses, the lens parameters and the aspherical coefficients of the eight lenses are determined.

4. The lens assembly according to claim 3, wherein The gaps and thicknesses between the lenses satisfy the following conditions: 1.2 < ALT / AAG < 3.0; Wherein, AAG is the sum of the seven air gaps between the first lens and the eighth lens.

5. The lens assembly according to claim 3, wherein The thicknesses of the lenses satisfy the following conditional formula: 2.0 < Tmax / Tmin < 4.5; Wherein, Tmax is the maximum value of the thicknesses of the lenses from the first lens to the eighth lens, and Tmin is the minimum value of the thicknesses of the lenses from the first lens to the eighth lens.

6. The lens assembly according to claim 3, wherein The gaps between the lenses satisfy the following conditional formula: 2.6 < Gmax / Gmin < 25.0; Wherein, Gmax is the maximum value of the seven air gaps between the first lens and the eighth lens, and Gmin is the minimum value of the seven air gaps between the first lens and the eighth lens.

7. The lens assembly according to claim 3, wherein Based on the central thicknesses of the lenses, the lens parameters and aspherical coefficients are determined.

8. The lens assembly according to claim 7, wherein The central thicknesses of the lenses satisfy the following conditional formula: 0.9 < (T1 + T6 + T7 + T8) / (T2 + T3 + T4 + T5) < 3; Among them, T1 is the center thickness of the first lens, T2 is the center thickness of the second lens, T3 is the center thickness of the third lens, T4 is the center thickness of the fourth lens, T5 is the center thickness of the fifth lens, T6 is the center thickness of the sixth lens, T7 is the center thickness of the seventh lens, and T8 is the center thickness of the eighth lens.

9. The lens assembly according to claim 7, characterized in that: The center thickness of the lens satisfies the following conditional formula: 3<(T1+T2+T3+T4+T5) / T3<8; Among them, T1 is the center thickness of the first lens, T2 is the center thickness of the second lens, T3 is the center thickness of the third lens, T4 is the center thickness of the fourth lens, T5 is the center thickness of the fifth lens, T6 is the center thickness of the sixth lens, T7 is the center thickness of the seventh lens, and T8 is the center thickness of the eighth lens.

10. The lens assembly according to claim 2, characterized in that: The lens parameters and the aspheric coefficients are determined based on the focal length of the lens.

11. The lens assembly according to claim 10, characterized in that: The focal length of the lens satisfies the following condition: 1.0<|f2 / f1|<4.5; Wherein, f1 is the focal length of the first lens, and f2 is the focal length of the second lens.

12. The lens assembly according to claim 10, characterized in that: The focal length of the lens satisfies the following condition: 0.23<|EFL / f2|+|EFL / f3|<2.5; Wherein, f2 is the focal length of the second lens, and f3 is the focal length of the third lens.

13. The lens assembly according to claim 2, characterized in that: The lens parameters and the aspheric coefficients are determined based on the center distances between adjacent lenses.

14. The lens assembly according to claim 13, characterized in that: The center distance of the lens satisfies the following conditional formula: 1.5<(G23+G34+G56) / (G12+G45+G67+G78)<3.6; Among them, G12 is the distance between the first lens and the second lens on the optical axis, G23 is the distance between the second lens and the third lens on the optical axis, G34 is the distance between the third lens and the fourth lens on the optical axis, G45 is the distance between the fourth lens and the fifth lens on the optical axis, G56 is the distance between the fifth lens and the sixth lens on the optical axis, G67 is the distance between the sixth lens and the seventh lens on the optical axis, and G78 is the distance between the seventh lens and the eighth lens on the optical axis.

15. The lens assembly according to claim 13, wherein: The center distance of the lens satisfies the following conditional formula: 4<(G23+G34+G56+OBFL) / (G12+G45+G67+G78)<14; Among them, G12 is the distance between the first lens and the second lens on the optical axis, G23 is the distance between the second lens and the third lens on the optical axis, G34 is the distance between the third lens and the fourth lens on the optical axis, G45 is the distance between the fourth lens and the fifth lens on the optical axis, G56 is the distance between the fifth lens and the sixth lens on the optical axis, G67 is the distance between the sixth lens and the seventh lens on the optical axis, G78 is the distance between the seventh lens and the eighth lens on the optical axis, and OBFL is the distance from the image side surface of the eighth lens to the imaging plane on the optical axis.

16. The lens assembly according to claim 2, wherein: The lens parameters and the aspheric coefficients are determined based on the entrance pupil diameter of the lens assembly.

17. The lens assembly according to claim 16, wherein: The entrance pupil diameter satisfies the following conditional formula: 1.45 <TL / EPD<1.90; Wherein, EPD is the entrance pupil diameter of the lens assembly.

18. The lens assembly according to claim 16, wherein: The entrance pupil diameter satisfies the following conditional formula: 16.0 <HFOV*EPD / EFL<19.3; Wherein, EPD is the entrance pupil diameter of the lens assembly; HFOV is the half field of view angle of the lens assembly.

19. The lens assembly according to claim 16, wherein: The entrance pupil diameter satisfies the following conditional formula: 2.8 <TTL*IMH / (EPD*AP8)<3.6; Among them, EPD is the entrance pupil diameter of the lens assembly; AP8 is the maximum effective diameter radius size of the eighth lens.

20. The lens assembly according to claim 2, wherein: The lens parameters and the aspheric coefficients are determined based on the following conditional expressions: 0.58 <CP72 / CP82<1.3; Among them, CP72 is the distance from the critical point of the image plane of the seventh lens to the optical axis, and CP82 is the distance from the critical point of the image plane of the eighth lens to the optical axis.

21. The lens assembly according to any one of claims 1 to 20, characterized in that: The lens group can move along the optical axis direction; Wherein, when the lens assembly is in a working state, the distance between the lens group and the imaging surface of the photosensitive element is a first distance; when the lens assembly is in a non-working state, the distance between the lens group and the imaging surface of the photosensitive element is a second distance, and the first distance is greater than the second distance.

22. The lens assembly according to claim 21, characterized in that: The lens assembly comprises: A driving member is used to drive the lens group to move.

23. The lens assembly according to claim 21, characterized in that: A color filter is arranged between the photosensitive element and the lens group, and the color filter can move closer to or away from the photosensitive element along the optical axis direction; Among them, when the lens assembly is in a working state, the distance between the color filter and the imaging surface of the photosensitive element is a third distance; when the lens assembly is in a non-working state, the distance between the color filter and the imaging surface of the photosensitive element is a fourth distance, and the third distance is greater than the fourth distance.

24. A mobile terminal, characterized in that: include: A lens assembly as claimed in any one of claims 1 to 23.

Images