Telephoto lens set, lens module and electronic equipment

Abstract

The present application discloses a telephoto lens group, a lens module and an electronic device. The telephoto lens group includes a first lens with positive refractive power, a second lens to a sixth lens with refractive power, and a seventh lens with negative refractive power, which are arranged in sequence from the object side to the image side. The surface shapes of the lenses of the telephoto lens group are reasonably matched, so that the structures of the lenses can be adjusted to meet the requirements of the telephoto lens group for telephoto and large aperture, so that the telephoto lens group can obtain a larger luminous flux and improve the pixels of the image taken by the telephoto lens group. The telephoto lens group also satisfies the conditional formula 43*f / (2*ImgH)>98, where ImgH is half of the image height corresponding to the maximum field angle of the telephoto lens group, and f is the effective focal length of the telephoto lens group. The telephoto lens group can obtain an equivalent focal length of about 100mm within the range of the above conditional formula, further meeting the requirements of telephoto, so that the lens module and electronic device equipped with the telephoto lens group can also obtain telephoto, large light flux and high pixel shooting performance.

Description

Technical Field

[0001] The present application relates to the technical field of optical systems, and in particular to a telephoto lens group, a lens module and an electronic device. Background Art

[0002] A telephoto lens has a long focal length, a small viewing angle, and a large image on the film. Therefore, it can produce a larger image than a standard lens at the same distance, making it suitable for photographing distant objects. Since its depth of field is smaller than that of a standard lens, it can more effectively blur the background and highlight the focused subject. In addition, the subject is generally far away from the camera, so there is less distortion in the perspective of the portrait, and the portrait is more vivid. Therefore, people often call telephoto lenses portrait lenses. However, due to the limitations of the optical characteristics of the telephoto lens itself, its aperture is small. If a larger aperture is designed, the aperture of the telephoto lens will be much larger than the image plane, making the radial size of the telephoto lens too large. If a large image plane is designed, the telephoto lens will be too long overall. Summary of the invention

[0003] The present application provides a telephoto lens group, a lens module and an electronic device, which can balance the aperture and image plane requirements of the telephoto lens and improve the imaging quality of the telephoto lens group on the basis of meeting the telephoto requirements.

[0004] In a first aspect, the telephoto lens assembly provided in an embodiment of the present application comprises, in order from the object side to the image side along the optical axis:

[0005] A first lens having positive refractive power, wherein the object side surface of the first lens is a convex surface;

[0006] a second lens having a refractive power;

[0007] A third lens having a refractive power, wherein the object side surface of the third lens is a concave surface at a position close to the optical axis;

[0008] A fourth lens element having a refractive power, wherein the image side surface of the fourth lens element is a concave surface at a position close to the optical axis;

[0009] A fifth lens having a refracting power, wherein the image side surface of the fifth lens is a concave surface at a position close to the optical axis;

[0010] A sixth lens having a refractive power, wherein the image side surface of the sixth lens is a convex surface near the optical axis;

[0011] a seventh lens having negative refractive power, wherein the image side surface of the seventh lens is concave at a position close to the optical axis, and at least one inflection point is provided on at least one of the object side surface and the image side surface of the seventh lens;

[0012] The telephoto lens group also satisfies the condition: 43*f / (2*ImgH)>98(1), where ImgH is half of the image height corresponding to the maximum field of view angle of the telephoto lens group, and f is the effective focal length of the telephoto lens group.

[0013] Based on the telephoto lens group provided in the embodiment of the present application, the surface shapes of each lens are reasonably matched, so that the structure of each lens can be adjusted to meet the requirements of the telephoto lens group for telephoto, and at the same time, the structure of the telephoto lens group can be adjusted to obtain a larger aperture, so that the telephoto lens group can obtain a larger luminous flux and improve the pixels of the image taken by the telephoto lens group. Furthermore, the telephoto lens group also satisfies the conditional formula 43*f / (2*ImgH)>98(1), so that the telephoto lens group can obtain an equivalent focal length of about 100mm within the range of conditional formula (1), thereby meeting the requirements of telephoto.

[0014] In some exemplary embodiments, the telephoto lens group further includes an aperture stop disposed on the image side of the first lens, and the telephoto lens group satisfies the condition: f / EPD≤2.55(2), wherein f is the effective focal length of the telephoto lens group, and EPD is the diameter of the effective light opening of the aperture stop.

[0015] Based on the above embodiment, the size of the effective aperture of the diaphragm determines the amount of light from the object side that can enter the telephoto lens group. By controlling the ratio of the two parameters of the effective focal length f of the telephoto lens group and the diameter EPD of the effective aperture of the diaphragm to satisfy the above conditional formula (2), it is possible to ensure that the telephoto lens group has sufficient luminous flux on the basis of controlling the length of the telephoto lens group, avoid dark corners at the edge of the photosensitive area in the imaging plane, and enable the telephoto lens group to obtain sufficient light intake to improve the shooting effect in dark environments. Increasing the effective aperture of the diaphragm requires the size of the imaging area in the imaging plane to be increased simultaneously to meet the resolution requirements, but increasing the imaging area in the imaging plane will result in an excessively large volume of the telephoto lens group. By controlling the ratio of the two parameters of f and EPD to satisfy the above conditional formula (2), the refractive power of each lens can be matched within a suitable range, and the volume of the telephoto lens group can be controlled on the basis of meeting the high pixel requirements.

[0016] In some exemplary embodiments, the telephoto lens group satisfies the condition: TTL / ImgH<4.5(3), wherein TTL is the distance from the object side of the first lens to the image plane of the telephoto lens group on the optical axis, and ImgH is half of the image height corresponding to the maximum field of view angle of the telephoto lens group.

[0017] Based on the above embodiment, a photosensitive element for receiving light can be installed in the imaging surface of the telephoto lens group. The size of ImgH determines the size of the photosensitive element for receiving light on the imaging surface of the telephoto lens group. The larger the ImgH is, the higher the pixel of the photosensitive element supported by the telephoto lens group can be. However, as ImgH increases, the length of the telephoto lens group needs to be increased synchronously. By controlling the ratio of the two parameters TTL and ImgH to satisfy the above conditional formula (3), the length of the telephoto lens group can be controlled, making it easy to achieve ultra-thin and miniaturized design of the telephoto lens group. The size and refractive power of each lens can also be matched according to the ratio of the two parameters TTL and ImgH to ensure the compactness of the telephoto lens group structure and good imaging quality.

[0018] In some exemplary embodiments, the telephoto lens group satisfies the condition: TTL / f<0.95(4), wherein TTL is the distance from the object side of the first lens to the image plane of the telephoto lens group on the optical axis, and f is the effective focal length of the telephoto lens group.

[0019] Based on the above embodiment, the distance TTL (i.e., the total optical length) from the object side of the first lens of the telephoto lens group to the image plane of the telephoto lens group on the optical axis is positively correlated with the effective focal length f of the telephoto lens group. The increase in the effective focal length f of the telephoto lens group requires the increase in the total optical length TTL. By controlling the ratio of the two parameters TTL and f to satisfy the above conditional formula (4), the telephoto lens group can obtain the telephoto characteristic while also controlling the length of the telephoto lens group so that the telephoto lens group meets the requirements of miniaturization design.

[0020] In some exemplary embodiments, the telephoto lens group satisfies the condition: |f / f4|≤2.1(5), wherein f is the effective focal length of the telephoto lens group, and f4 is the effective focal length of the fourth lens.

[0021] Based on the above embodiments, the fourth lens may have a positive refractive power or a negative refractive power. By controlling the absolute value of the ratio of the two parameters of the effective focal length f of the telephoto lens group and the effective focal length f4 of the fourth lens to satisfy the above conditional formula (5), the overall refractive power of the telephoto lens group can be adjusted within a suitable range, so that the chromatic aberration produced by the first lens, the second lens and the third lens can be smoothed, and the high-order aberrations caused by the excessive refractive index of the first three lenses can be reduced.

[0022] In some exemplary embodiments, the telephoto lens group satisfies the condition: |f7 / R71|<14.8(6), wherein f7 is the effective focal length of the seventh lens element, and R71 is the radius of curvature of the object side of the seventh lens element at the optical axis.

[0023] Based on the above embodiment, the seventh lens L7 has negative refractive power, and at least one of the object-side surface and the image-side surface of the seventh lens is provided with at least one inflection point, so as to reasonably distribute the refractive power. By controlling the ratio of the two parameters, the effective focal length f7 of the seventh lens and the radius of curvature R71 of the object-side surface of the seventh lens at the optical axis, to satisfy the above conditional formula (6), the aberration generated by the lens before the seventh lens can be effectively improved when the light passes through the seventh lens, thereby improving the light resolution capability of the photosensitive element in the imaging plane.

[0024] In some exemplary embodiments, the telephoto lens group satisfies the condition: (CT1+CT2+C3+CT4) / TTL≤0.32(7), wherein CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, CT4 is the thickness of the fourth lens on the optical axis, and TTL is the distance from the object side of the first lens to the image plane of the telephoto lens group on the optical axis.

[0025] Based on the above embodiment, controlling the thickness of the lens at the front end can effectively reduce the difficulty of processing and assembling each lens. By controlling the sum of the four parameters CT1, CT2, CT3, and CT4 and the total optical length TTL of the telephoto lens group to satisfy the above conditional formula (7), the thickness of the four lenses at the front end can be adjusted to a suitable range, which is convenient for lens processing and assembly. It is also possible to adjust the proportion of each lens at the front end to the entire optical length, so as to adjust the spacing between the lenses, effectively improve the compactness of the telephoto lens group structure, and facilitate lens molding and assembly.

[0026] In some exemplary embodiments, the telephoto lens group satisfies the condition: 0.7<ΣCT / ΣAT<1.7(8), wherein ΣCT is the sum of the thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens on the optical axis, and ΣAT is the sum of the intervals between the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens on the optical axis.

[0027] Based on the above embodiment, by controlling the two parameters ΣCT and ΣAT to satisfy the above conditional formula (8), the thickness of each lens and the distance between two adjacent lenses can be adjusted to a suitable range, which is helpful to improve the imaging quality and can also make the light pass smoothly through each lens. If ΣCT / ΣAT is higher than the upper limit of 1.7 of conditional formula (8), it may cause the thickness of each lens to be too large, which is not conducive to the convergence and diffusion of light between the lenses, forcing the lens surface to have a larger bending amplitude to change the direction of light, increasing the difficulty of manufacturing the lens. If ΣCT / ΣAT is lower than the lower limit of 0.7 of conditional formula (8), the thickness of each lens is too low, and it is difficult to obtain a more ideal bending ability to change the direction of light, thereby resulting in a decrease in imaging quality.

[0028] In some exemplary embodiments, the telephoto lens group satisfies the conditional formula: 0.2 < BF / TTL < 0.37(9), where BF is the minimum distance from the image side surface of the seventh lens to the imaging surface of the telephoto lens group parallel to the optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface of the telephoto lens group on the optical axis.

[0029] Based on the above embodiments, by controlling the two parameters BF and TTL to satisfy the above conditional formula (9), the ratio of the minimum distance BF from the image side surface of the seventh lens to the imaging surface of the telephoto lens group parallel to the optical axis occupying the total optical length TTL can be adjusted within the range of the conditional formula (9), which is convenient for the assembly of the telephoto lens group, and also helps to reduce the incident angle of the light rays entering the effective imaging area in the imaging surface from the seventh lens, improve the relative illumination, and thus improve the imaging quality. If BF / TTL is lower than the lower limit 0.2 of the conditional formula (9), the distance between the image side surface of the seventh lens and the imaging surface is too small, resulting in insufficient installation space for the telephoto lens group. If BF / TTL is higher than the upper limit 0.37 of the conditional formula (9), the distance between the image side surface of the seventh lens and the imaging surface is too large, which is not convenient for the assembly of the telephoto lens group and increases the volume of the telephoto lens group.

[0030] In a second aspect, the lens module provided by the embodiments of the present application includes a photosensitive element and the above telephoto lens group. The photosensitive element is disposed in the imaging surface of the telephoto lens group, where the telephoto lens group is configured to receive the light reflected by the object to be photographed and project it onto the photosensitive element, and the photosensitive element is configured to convert the light into an image signal.

[0031] Based on the lens module provided by the embodiments of the present application, by installing the above-described telephoto lens group, on the basis that the telephoto lens group can satisfy telephoto long-focus shooting and obtain a large light flux, the lens module can also meet the shooting requirements of telephoto long-focus and large light flux, and obtain high-pixel shooting performance.

[0032] In a third aspect, the electronic device provided by the embodiments of the present application includes a housing and the above lens module, and the lens module is installed in the housing.

[0033] Based on the electronic device provided by the embodiments of the present application, by installing the above-described lens module in the electronic device, the electronic device can also obtain the shooting performance of telephoto long-focus, large light flux, and high pixels.

[0034] The telephoto lens group, lens module and electronic device provided by the present application reasonably match the surface shapes of each lens of the telephoto lens group, so as to facilitate the adjustment of each lens structure to meet the requirements of the telephoto lens group for telephoto, and at the same time facilitate the adjustment of the telephoto lens group structure to obtain a larger aperture, so that the telephoto lens group obtains a larger luminous flux and improves the pixels of the image taken by the telephoto lens group. The telephoto lens group also satisfies the conditional formula 43*f / (2*ImgH)>98, where ImgH is half of the image height corresponding to the maximum field of view of the telephoto lens group, and f is the effective focal length of the telephoto lens group, so that the telephoto lens group can obtain an equivalent focal length of about 100mm within the range of the above conditional formula, further meeting the requirements of telephoto. The lens module and electronic device equipped with the telephoto lens group can also obtain telephoto, large light flux and high pixel shooting performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic diagram of the structure of a telephoto lens assembly provided in Example 1 of the present application;

[0037] Figure 2 A spherical aberration curve diagram, an astigmatism curve diagram, and a distortion curve diagram of the telephoto lens set provided in Example 1 of the present application;

[0038] Figure 3 A schematic diagram of the structure of a telephoto lens assembly provided in Embodiment 2 of the present application;

[0039] Figure 4 A spherical aberration curve diagram, an astigmatism curve diagram, and a distortion curve diagram of the telephoto lens set provided in Example 2 of the present application;

[0040] Figure 5 A schematic diagram of the structure of a telephoto lens assembly provided in Embodiment 3 of the present application;

[0041] Figure 6 The spherical aberration curve diagram, the astigmatism curve diagram, and the distortion curve diagram of the telephoto lens set provided in Example 3 of the present application;

[0042] Figure 7 A schematic diagram of the structure of a telephoto lens assembly provided in Embodiment 4 of the present application;

[0043] Figure 8 A spherical aberration curve diagram, an astigmatism curve diagram, and a distortion curve diagram of the telephoto lens set provided in Example 4 of the present application;

[0044] Fig. 9 A schematic diagram of the structure of a telephoto lens assembly provided in Embodiment 5 of the present application;

[0045] Fig.10 The spherical aberration curve, astigmatism curve, and distortion curve of the telephoto lens group provided in Example 5 of the present application. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] like Figures 1 to 10 As shown, the telephoto lens group provided in the embodiment of the present application includes a first lens L1, a second lens L2, a third lens, a fourth lens L4, a fifth lens L5, a sixth lens L6 and a seventh lens L7 which are arranged in sequence from the object side to the image side along the optical axis. The telephoto lens group also includes an imaging surface IMG. Light from the object side passes through the first lens L1 to the seventh lens L7 in sequence and is projected onto the imaging surface IMG. An optical element may be arranged in the imaging surface IMG. Light passing through the seventh lens L7 may be received by the optical element in the imaging surface IMG and converted into an image signal. The optical element then transmits the image signal to other control systems for image analysis and other processing.

[0048] The first lens L1 has positive refractive power. The object side surface of the first lens L1 is a convex surface. The image side surface of the first lens L1 can be a convex surface, a concave surface or a flat surface near the optical axis.

[0049] The second lens L2 may have positive or negative refractive power. The object-side surface and the image-side surface of the second lens L2 may be convex, concave or planar at the near optical axis.

[0050] The third lens L3 may have positive or negative refractive power. The object-side surface of the third lens L3 is concave at the near optical axis. The image-side surface of the third lens L3 may be convex, concave or flat at the near optical axis.

[0051] The fourth lens L4 may have positive refractive power or negative refractive power. The object-side surface of the fourth lens L4 may be a convex surface, a concave surface or a plane surface at the near optical axis. The image-side surface of the fourth lens L4 is a concave surface at the near optical axis.

[0052] The fifth lens L5 may have positive or negative refractive power. The object-side surface of the fifth lens L5 may be a convex surface, a concave surface or a plane surface at the near optical axis. The image-side surface of the fifth lens L5 is a concave surface at the near optical axis.

[0053] The sixth lens L6 may have positive or negative refractive power. The object-side surface of the sixth lens L6 may be a convex surface, a concave surface or a plane surface near the optical axis. The image-side surface of the sixth lens L6 is a convex surface near the optical axis.

[0054] The seventh lens L7 may have negative refractive power, the object side surface of the seventh lens L7 may be a convex surface, a concave surface or a plane surface near the optical axis, the image side surface of the seventh lens L7 is a concave surface near the optical axis, and at least one inflection point is disposed on at least one of the object side surface and the image side surface of the seventh lens L7.

[0055] The telephoto lens group also satisfies the condition: 43*f / (2*ImgH)>98(1), where ImgH is half of the image height corresponding to the maximum field of view angle of the telephoto lens group, and f is the effective focal length of the telephoto lens group.

[0056] Based on the telephoto lens group provided in the embodiment of the present application, the surface shapes of each lens are reasonably matched, so that the structure of each lens can be adjusted to meet the requirements of the telephoto lens group for telephoto, and at the same time, the structure of the telephoto lens group can be adjusted to obtain a larger aperture, so that the telephoto lens group can obtain a larger luminous flux and improve the pixels of the image taken by the telephoto lens group. Furthermore, the telephoto lens group also satisfies the conditional formula 43*f / (2*ImgH)>98(1), so that the telephoto lens group can obtain an equivalent focal length of about 100mm within the range of conditional formula (1), thereby meeting the requirements of telephoto.

[0057] The telephoto lens group further includes a stop ST disposed on the object side of the first lens L1. Preferably, the stop ST is disposed on the edge of the object side of the first lens L1 to block the entry of external stray light and control the luminous flux of each lens installed at the rear end of the first lens L1.

[0058] The telephoto lens group also includes a light reflecting element F arranged adjacent to the object side surface of the first lens L1. The light reflecting element F includes an exit surface R3 arranged perpendicular to the optical axis direction of the first lens L1, an incident surface R1 arranged perpendicular to the exit surface R3, and a reflecting surface R2 connecting the exit surface R3 and the incident surface R1. The angle between the reflecting surface R2 and the optical axis direction of the first lens L1 can range from 30 degrees to 60 degrees. Preferably, the above-mentioned degree range can be 45 degrees, so that the light from the object side can be bent 90 degrees by the reflecting surface R2 and then projected onto the first lens L1 to change the direction of the light path. For example, the direction of the light path can be changed from horizontal to vertical, so that the telephoto lens group changes the focal depth in the vertical direction, thereby saving the zooming space of the telephoto lens group in the horizontal direction.

[0059] The telephoto lens group also includes an infrared filter L8, which is disposed between the seventh lens L7 and the imaging surface IMG. The light emitted from the seventh lens L7 passes through the infrared filter L8 and then is projected into the imaging surface IMG. The infrared filter L8 can be used to filter a portion of the light to reduce stray light and light spots, etc., so that the final image is bright and sharp while having good color reproduction.

[0060] The first lens L1 to the seventh lens L7 can all be aspherical lenses made of plastic material. Plastic material is easy to process into aspherical lenses. The aspherical lenses can have a better curvature radius at the optical axis and can maintain good aberration correction capability.

[0061] In some exemplary embodiments, the telephoto lens group satisfies the condition: f / EPD≤2.55(2), wherein f is the effective focal length of the telephoto lens group, and EPD is the diameter of the effective light opening of the aperture ST.

[0062] Based on the above embodiment, the size of the effective light opening of the aperture ST determines the amount of light that can enter the telephoto lens group from the object side. By controlling the ratio of the two parameters of the effective focal length f of the telephoto lens group and the diameter EPD of the effective light opening of the aperture ST to satisfy the above conditional formula (2), it is possible to ensure that the telephoto lens group has sufficient luminous flux on the basis of controlling the length of the telephoto lens group, avoid the occurrence of dark corners at the edge of the photosensitive area in the imaging surface IMG, and enable the telephoto lens group to obtain sufficient light intake to improve the shooting effect in dark environments. Increasing the effective light opening of the aperture ST requires the simultaneous increase of the size of the imaging area in the imaging surface IMG to meet the resolution requirements, but increasing the imaging area in the imaging surface IMG will result in an excessively large volume of the telephoto lens group. By controlling the ratio of the two parameters of f and EPD to satisfy the above conditional formula (2), the refractive power of each lens can be matched within a suitable range, and the volume of the telephoto lens group can be controlled on the basis of meeting the high pixel requirements.

[0063] In some exemplary embodiments, the telephoto lens group satisfies the condition: TTL / ImgH<4.5(3), wherein TTL is the distance from the object side of the first lens L1 to the image plane IMG of the telephoto lens group on the optical axis, and ImgH is half of the image height corresponding to the maximum field of view angle of the telephoto lens group.

[0064] Based on the above embodiment, a photosensitive element for receiving light can be installed in the imaging surface IMG of the telephoto lens group. The size of ImgH determines the size of the photosensitive element for receiving light on the imaging surface IMG of the telephoto lens group. The larger the ImgH is, the higher the pixel of the photosensitive element supported by the telephoto lens group can be. However, as ImgH increases, the length of the telephoto lens group needs to be increased synchronously. By controlling the ratio of the two parameters TTL and ImgH to satisfy the above conditional formula (3), the length of the telephoto lens group can be controlled, so that the telephoto lens group can be easily designed to be ultra-thin and miniaturized. The size and refractive power of each lens can also be matched according to the ratio of the two parameters TTL and ImgH to ensure the compactness of the telephoto lens group structure and good imaging quality.

[0065] In some exemplary embodiments, the telephoto lens group satisfies the condition: TTL / f<0.95(4), wherein TTL is the distance from the object side of the first lens L1 to the image plane IMG of the telephoto lens group on the optical axis, and f is the effective focal length of the telephoto lens group.

[0066] Based on the above embodiment, the distance TTL (i.e., the total optical length) from the object side of the first lens L1 of the telephoto lens group to the image plane IMG of the telephoto lens group on the optical axis is positively correlated with the effective focal length f of the telephoto lens group. The increase in the effective focal length f of the telephoto lens group requires the simultaneous increase in the total optical length TTL. By controlling the ratio of the two parameters TTL and f to satisfy the above conditional formula (4), the telephoto lens group can obtain the telephoto characteristic while also controlling the length of the telephoto lens group so that the telephoto lens group meets the miniaturization design requirements.

[0067] In some exemplary embodiments, the telephoto lens group satisfies the condition: |f / f4|≤2.1(5), where f is the effective focal length of the telephoto lens group, and f4 is the effective focal length of the fourth lens L4.

[0068] Based on the above embodiment, the fourth lens L4 may have a positive refractive power or a negative refractive power. By controlling the absolute value of the ratio of the two parameters, the effective focal length f of the telephoto lens group and the effective focal length f4 of the fourth lens L4, to satisfy the above conditional formula (5), the refractive power of the entire telephoto lens group may be adjusted within a suitable range, so that the chromatic aberration generated by the first lens L1, the second lens L2 and the third lens L3 can be smoothed, and the high-order aberrations caused by the excessive refractive index of the first three lenses can be reduced.

[0069] In some exemplary embodiments, the telephoto lens group satisfies the condition: |f7 / R71|<14.8(6), wherein f7 is the effective focal length of the seventh lens L7, and R71 is the radius of curvature of the object side of the seventh lens L7 at the optical axis.

[0070] Based on the above embodiment, the seventh lens L7 has negative refractive power, and at least one of the object side surface and the image side surface of the seventh lens L7 is provided with at least one inflection point, so as to reasonably distribute the distribution of the refractive power. By controlling the ratio of the two parameters, the effective focal length f7 of the seventh lens L7 and the curvature radius R71 of the object side surface of the seventh lens L7 at the optical axis, to satisfy the above conditional formula (6), the aberration generated by the lens before the seventh lens L7 can be effectively improved when the light passes through the seventh lens L7, and the light resolution capability of the photosensitive element in the imaging surface IMG can be improved. When f7 / R71|≥14.8, the effective focal length of the seventh lens L7 is too large, and the distance between the seventh lens and the imaging surface needs to be increased so that all the light can be projected into the effective imaging area of ​​the imaging surface IMG, which is not conducive to reducing the volume of the telephoto lens group; or the curvature radius of the seventh lens L7 at the optical axis is too small, so that the seventh lens L7 has too small a deflection capability of the light passing through the interior thereof and fails to improve the aberration well.

[0071] In some exemplary embodiments, the telephoto lens group satisfies the condition: (CT1+CT2+CT3+CT4) / TTL≤0.32(7), wherein CT1 is the thickness of the first lens L1 on the optical axis, CT2 is the thickness of the second lens L2 on the optical axis, CT3 is the thickness of the third lens L3 on the optical axis, and CT4 is the thickness of the fourth lens L4 on the optical axis.

[0072] Based on the above embodiment, controlling the thickness of the lens at the front end can effectively reduce the difficulty of processing and assembling each lens. By controlling the sum of the four parameters CT1, CT2, CT3, and CT4 and the total optical length TTL of the telephoto lens group to satisfy the above conditional formula (7), the thickness of the four lenses at the front end can be adjusted to a suitable range, which is convenient for lens processing and assembly. It is also possible to adjust the proportion of each lens at the front end to the entire optical length, so as to adjust the spacing between the lenses, effectively improve the compactness of the telephoto lens group structure, and facilitate lens molding and assembly.

[0073] In some exemplary embodiments, the telephoto lens group satisfies the condition: 0.7<ΣCT / ΣAT<1.7(8), wherein ΣCT is the sum of the thicknesses of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 on the optical axis, and ΣAT is the sum of the intervals between the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 on the optical axis.

[0074] Based on the above embodiments, by controlling the two parameters of ΣCT and ΣAT to satisfy the above conditional formula (8), the thickness of each lens and the distance between two adjacent lenses can be adjusted to an appropriate range, which helps to improve the imaging quality and enables the light to smoothly transition when passing through each lens. If ΣCT / ΣAT is higher than the upper limit of 1.7 of the conditional formula (8), it may cause the thickness of each lens to be too large, which is not conducive to the convergence and divergence of light between the lenses, forcing the lens surface to have a greater bending amplitude to change the light trend and increasing the manufacturing difficulty of the lens. If ΣCT / ΣAT is lower than the lower limit of 0.7 of the conditional formula (8), the thickness of each lens is too low, making it difficult to obtain an ideal bending ability to change the light direction, resulting in a decline in imaging quality.

[0075] In some exemplary embodiments, the telephoto lens group satisfies the conditional formula: 0.2 < BF / TTL < 0.37 (9), where BF is the minimum distance parallel to the optical axis from the image side of the seventh lens L7 to the imaging surface IMG of the telephoto lens group, and TTL is the distance from the object side of the first lens L1 to the imaging surface IMG of the telephoto lens group on the optical axis.

[0076] Based on the above embodiments, by controlling the two parameters of BF and TTL to satisfy the above conditional formula (9), the ratio of the minimum distance BF parallel to the optical axis from the image side of the seventh lens L7 to the imaging surface IMG of the telephoto lens group occupying the total optical length TTL can be adjusted within the range of the conditional formula (9), which is convenient for the assembly of the telephoto lens group and also helps to reduce the incident angle of the light entering the effective imaging area in the imaging surface IMG from the seventh lens L7, improve the relative illumination, and further improve the imaging quality. If BF / TTL is lower than the lower limit of 0.2 of the conditional formula (9), the distance between the image side of the seventh lens L7 and the imaging surface IMG is too small, resulting in insufficient installation space for the telephoto lens group. If BF / TTL is higher than the upper limit of 0.37 of the conditional formula (9), the distance between the image side of the seventh lens L7 and the imaging surface IMG is too large, which is not convenient for the assembly of the telephoto lens group and increases the volume of the telephoto lens group at the same time.

[0077] In a second aspect, the lens module provided by the embodiments of the present application includes a photosensitive element and the above-mentioned telephoto lens group. The photosensitive element is disposed in the imaging surface IMG of the telephoto lens group, where the telephoto lens group is used to receive the light reflected by the object to be photographed and project it onto the photosensitive element, and the photosensitive element is used to convert the light into an image signal. The photosensitive element can be a photosensitive chip. The lens module provided by the embodiments of the present application, by installing the above-mentioned telephoto lens group, on the basis that the telephoto lens group can meet the requirements of telephoto long shot and obtain a large light flux, the lens module can also meet the shooting requirements of telephoto long shot and large light flux, and obtain high-pixel shooting performance.

[0078] In a third aspect, the electronic device provided by the embodiment of the present application includes a housing and the lens module as described above, and the lens module is installed in the housing. The electronic device provided by the embodiment of the present application can also obtain long-focus telephoto, large light throughput and high-pixel shooting performance by installing the lens module as described above in the electronic device.

[0079] The following will refer to the accompanying drawings and tables to introduce the assembly structure of the telephoto lens group of the present technical solution in various specific implementations and the corresponding implementation results in combination with specific numerical values.

[0080] The meanings of the symbols shown in the examples are as follows.

[0081] S1, S3, S5, S7, S9, S11, S13, and S15 are the numbers of the object-side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared filter L8, respectively. S2, S4, S6, S8, S10, S12, S14, and S16 are the numbers of the image-side surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the infrared filter L8, respectively.

[0082] “k” represents the conic constant, and “A4”, “A6”, “A8”, …, and “A20” represent the 4th-order, 6th-order, 8th-order, …, and 20th-order aspheric coefficients, respectively.

[0083] In the following tables showing conic constants and aspheric coefficients, numerical values ​​are expressed using exponential expressions with a base of 10. For example, "0.12E-05" means "0.12×(10 to the negative fifth power)" and "9.87E+03" means "9.87×(10 to the third power)".

[0084] In the optical imaging lens used in each embodiment, specifically, if the distance in the direction perpendicular to the optical axis H is set to "r", the paraxial curvature at the lens origin is set to "c" (the paraxial curvature c is the reciprocal of the upper lens curvature radius R, that is, c = 1 / R), the cone constant is set to "k", and the 4th, 6th, 8th, ..., i-th order aspheric coefficients are set to "A4", "A6", "A8", ..., "Ai" respectively, then the aspheric shape x is defined by the following mathematical formula 1.

[0085] Mathematical formula 1:

[0086]

[0087] Embodiment 1

[0088] The structural diagram of the telephoto lens group in this embodiment is shown in FIG. Figure 1 As shown, the telephoto lens group includes a light reflecting element F, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and an infrared filter L8, which are arranged in sequence from the object side to the image side, and an aperture ST is arranged at the edge of the object side of the first lens L1.

[0089] The first lens L1 has positive refractive power, the object side surface of the first lens L1 is convex at the near optical axis, the image side surface is concave at the near optical axis, the object side surface of the first lens L1 is convex at the circumference, and the image side surface is concave at the circumference.

[0090] The second lens L2 has positive refractive power, the object side surface of the second lens L2 is convex at the near optical axis, the image side surface is concave at the near optical axis, and both the object side surface and the image side surface of the second lens L2 are convex on the circumference.

[0091] The third lens L3 has negative refractive power. The object side surface and the image side surface of the third lens L3 are both concave surfaces at the near optical axis. The object side surface of the third lens L3 is convex on the circumference, and the image side surface is concave on the circumference.

[0092] The fourth lens L4 has negative refractive power, the object side surface of the fourth lens L4 is convex at the near optical axis, the image side surface is concave at the near optical axis, the object side surface of the fourth lens L4 is convex on the circumference, and the image side surface is concave on the circumference.

[0093] The fifth lens L5 has negative refractive power. The object side surface of the fifth lens L5 is convex at the near optical axis, and the image side surface is concave at the near optical axis. The object side surface of the fifth lens L5 is convex on the circumference, and the image side surface is concave on the circumference.

[0094] The sixth lens L6 has positive refractive power. The object side surface and the image side surface of the sixth lens L6 are both convex surfaces near the optical axis. The object side surface of the sixth lens L6 is convex on the circumference, and the image side surface is concave on the circumference.

[0095] The seventh lens L7 has negative refractive power. The object side surface of the seventh lens L7 is convex at the near optical axis, and the image side surface is concave at the near optical axis. The object side surface of the seventh lens L7 is concave at the circumference, and the image side surface is convex at the circumference.

[0096] In Example 1, the refractive index and Abbe number of the telephoto lens group are both based on the light with a wavelength of 587.60 nm, and the focal length is based on the light with a wavelength of 555.00 nm. The relevant parameters of the telephoto lens group are shown in Table 1. Among them, f is the effective focal length of the telephoto lens group, FNO represents the aperture value, FOV represents the maximum field of view of the telephoto lens group, TTL is the distance from the object side of the first lens L1 to the imaging surface IMG on the optical axis, and the units of the curvature radius, thickness, and focal length are all millimeters.

[0097] Table 1

[0098]

[0099]

[0100] The calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment are obtained based on the parameters in Table 1, as shown in Table 2.

[0101] Table 2

[0102] Conditional expression Numeric Conditional expression Numeric 43*f / (2*ImgH) 101.528 |f7 / R71| 3.393 f / EPD 2.350 (CT1+CT2+CT3+CT4) / TTL 0.219 TTL / ImgH 4.167 0.7<ΣCT / ΣAT 0.709 TTL / f 0.882 0.2<BF / TTL 0.258 |f / f4| 0.294

[0103] According to the results in Table 2, the calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment respectively satisfy the conditional expressions (1) to (9) in a one-to-one correspondence.

[0104] The cone constant K and aspheric coefficient corresponding to the surface of each lens in Example 1 are shown in Table 3.

[0105] Table 3

[0106]

[0107]

[0108] Figure 2 From left to right in the figure are the spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram in the first embodiment.

[0109] The horizontal axis of the spherical aberration curve represents the focus offset, and the vertical axis represents the normalized field of view. Figure 2 When the wavelengths given in the left figure are 650.00nm, 610.00nm, 555.00nm, 510.00nm and 470.00nm respectively, the focus shifts of different fields of view are all within ±0.10 mm, indicating that the spherical aberration of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0110] The horizontal axis of the astigmatism curve represents the focus shift, and the vertical axis represents the image height, in millimeters. Figure 2 The astigmatism curve given in the middle figure shows that when the wavelength is 555.00nm, the focus shifts of the sagittal image plane and the meridional image plane are both within ±0.025 mm, indicating that the astigmatism of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0111] The horizontal axis of the distortion curve represents the distortion rate, and the vertical axis represents the image height, in millimeters. Figure 2 The distortion curve given in the middle right figure shows that the distortion rate is within ±1% when the wavelength is 555.00nm, which means that the distortion of the telephoto lens group in this embodiment is well corrected and the imaging quality is good.

[0112] according to Figure 2 It can be seen that the telephoto lens group provided in the first embodiment can achieve good imaging effects.

[0113] Embodiment 2

[0114] The structural diagram of the telephoto lens group in this embodiment is shown in FIG. Figure 3 As shown, the telephoto lens group includes a light reflecting element F, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and an infrared filter L8, which are arranged in sequence from the object side to the image side, and an aperture ST is arranged at the edge of the object side of the first lens L1.

[0115] The first lens L1 has positive refractive power, the object side surface of the first lens L1 is convex at the near optical axis, the image side surface is concave at the near optical axis, and both the object side surface and the image side surface of the first lens L1 are convex on the circumference.

[0116] The second lens L2 has positive refractive power, the second object-side surface is convex at the near optical axis, and the image-side surface is concave at the near optical axis, and both the object-side surface and the image-side surface of the second lens L2 are convex on the circumference.

[0117] The third lens L3 has negative refractive power. The object side surface and the image side surface of the third lens L3 are both concave surfaces at the near optical axis. The object side surface of the third lens L3 is convex on the circumference, and the image side surface is concave on the circumference.

[0118] The fourth lens L4 has negative refractive power, the object side surface of the fourth lens L4 is convex at the near optical axis, the image side surface is concave at the near optical axis, the object side surface of the fourth lens L4 is convex on the circumference, and the image side surface is concave on the circumference.

[0119] The fifth lens L5 has negative refractive power. The object side surface and the image side surface of the fifth lens L5 are both concave surfaces at the near optical axis. The object side surface of the fifth lens L5 is concave on the circumference, and the image side surface is convex on the circumference.

[0120] The sixth lens L6 has positive refractive power. The object side surface of the sixth lens L6 is concave at the near optical axis, and the image side surface is convex at the near optical axis. The object side surface of the sixth lens L6 is concave at the circumference, and the image side surface is convex at the circumference.

[0121] The seventh lens L7 has negative refractive power. The object side surface of the seventh lens L7 is convex at the near optical axis, and the image side surface is concave at the near optical axis. The object side surface of the seventh lens L7 is concave at the circumference, and the image side surface is convex at the circumference.

[0122] The refractive index and Abbe number of the telephoto lens group in Example 2 are both based on the light with a wavelength of 587.60 nm, and the focal length is based on the light with a wavelength of 555.00 nm. The relevant parameters of the telephoto lens group are shown in Table 4. Among them, f is the effective focal length of the telephoto lens group, FNO represents the aperture value, FOV represents the maximum field of view of the telephoto lens group, TTL is the distance from the object side of the first lens L1 to the imaging surface IMG on the optical axis, and the units of the curvature radius, thickness, and focal length are all millimeters.

[0123] Table 4

[0124]

[0125] The calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment are obtained based on the parameters in Table 4, as shown in Table 5.

[0126] Table 5

[0127] Conditional expression Numeric Conditional expression Numeric 43*f / (2*ImgH) 98.542 |f7 / R71| 14.799 f / EPD 2.400 (CT1+CT2+CT3+CT4) / TTL 0.225 TTL / ImgH 4.306 0.7<ΣCT / ΣAT 1.146 TTL / f 0.939 0.2<BF / TTL 0.356 |f / f4| 0.281

[0128] According to the results in Table 5, the calculated results of the numerical relationship between the relevant parameters of each lens in the telephoto lens group in this embodiment respectively satisfy the conditional expressions (1) to (9) in a one-to-one correspondence.

[0129] The cone constant K and aspheric coefficient corresponding to the surface of each lens in Example 2 are shown in Table 6.

[0130] Table 6

[0131]

[0132]

[0133] Figure 4 From left to right in the figure are the spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram in the second embodiment.

[0134] The horizontal axis of the spherical aberration curve represents the focus offset, and the vertical axis represents the normalized field of view. Figure 4 When the wavelengths given in the left figure are 650.00nm, 610.00nm, 555.00nm, 510.00nm and 470.00nm respectively, the focus shifts of different fields of view are all within ±0.05 mm, indicating that the spherical aberration of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0135] The horizontal axis of the astigmatism curve represents the focus shift, and the vertical axis represents the image height, in millimeters. Figure 4The astigmatism curve given in the middle figure shows that when the wavelength is 555.00nm, the focus shifts of the sagittal image plane and the meridional image plane are both within ±0.025 mm, indicating that the astigmatism of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0136] The horizontal axis of the distortion curve represents the distortion rate, and the vertical axis represents the image height, in millimeters. Figure 4 The distortion curve given in the middle right figure shows that the distortion rate is within ±1% when the wavelength is 555.00nm, which means that the distortion of the telephoto lens group in this embodiment is well corrected and the imaging quality is good.

[0137] according to Figure 4 It can be seen that the telephoto lens set provided in the second embodiment can achieve good imaging effects.

[0138] Embodiment 3

[0139] The structural diagram of the telephoto lens group in this embodiment is shown in FIG. Figure 5 As shown, the telephoto lens group includes a light reflecting element F, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and an infrared filter L8, which are arranged in sequence from the object side to the image side, and an aperture ST is arranged at the edge of the object side of the first lens L1.

[0140] The first lens L1 has positive refractive power, the object side surface and the image side surface of the first lens L1 are both convex at the near optical axis, the object side surface of the first lens L1 is convex at the circumference, and the image side surface is concave at the circumference.

[0141] The second lens L2 has negative refractive power. The object side surface and the image side surface of the second lens L2 are both concave surfaces at the near optical axis. The object side surface and the image side surface of the second lens L2 are both convex surfaces on the circumference.

[0142] The third lens L3 has negative refractive power. The object side surface and the image side surface of the third lens L3 are both concave surfaces at the near optical axis. The object side surface of the third lens L3 is convex on the circumference, and the image side surface is concave on the circumference.

[0143] The fourth lens L4 has negative refractive power. The object side surface and the image side surface of the fourth lens L4 are both concave surfaces at the near optical axis. The object side surface of the fourth lens L4 is convex on the circumference, and the image side surface is concave on the circumference.

[0144] The fifth lens L5 has positive refractive power. The object side surface of the fifth lens L5 is convex at the near optical axis, and the image side surface is concave at the near optical axis. The object side surface of the fifth lens L5 is concave at the circumference, and the image side surface is convex at the circumference.

[0145] The sixth lens L6 has negative refractive power. The object side surface of the sixth lens L6 is concave at the near optical axis, and the image side surface is convex at the near optical axis. The object side surface of the sixth lens L6 is concave at the circumference, and the image side surface is convex at the circumference.

[0146] The seventh lens L7 has negative refractive power. The object side surface and the image side surface of the seventh lens L7 are both concave surfaces at the near optical axis. The object side surface of the seventh lens L7 is concave on the circumference, and the image side surface is convex on the circumference.

[0147] The refractive index and Abbe number of the telephoto lens group in Example 3 are both based on the light with a wavelength of 587.60nm, and the focal length is based on the light with a wavelength of 555.00nm. The relevant parameters of the telephoto lens group are shown in Table 7. Among them, f is the effective focal length of the telephoto lens group, FNO represents the aperture value, FOV represents the maximum field of view of the telephoto lens group, TTL is the distance from the object side of the first lens L1 to the imaging surface IMG on the optical axis, and the units of the curvature radius, thickness, and focal length are all millimeters.

[0148] Table 7

[0149]

[0150] The calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment are obtained based on the parameters in Table 7 and are shown in Table 8.

[0151] Table 8

[0152] Conditional expression Numeric Conditional expression Numeric 43*f / (2*ImgH) 99.736 |f7 / R71| 0.084 f / EPD 2.450 (CT1+CT2+CT3+CT4) / TTL 0.303 TTL / ImgH 4.389 0.7<ΣCT / ΣAT 1.657 TTL / f 0.946 0.2<BF / TTL 0.209 |f / f4| 0.618

[0153] According to the results in Table 8, the calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment respectively satisfy the conditional expressions (1) to (9) in a one-to-one correspondence.

[0154] The cone constant K and aspheric coefficient corresponding to the surface of each lens in Example 3 are shown in Table 9.

[0155] Table 9

[0156]

[0157]

[0158] Figure 6 From left to right in the figure are the spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram in the third embodiment.

[0159] The horizontal axis of the spherical aberration curve represents the focus offset, and the vertical axis represents the normalized field of view. Figure 6When the wavelengths given in the left figure are 650.00nm, 610.00nm, 555.00nm, 510.00nm and 470.00nm respectively, the focus shifts of different fields of view are all within ±0.05 mm, indicating that the spherical aberration of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0160] The horizontal axis of the astigmatism curve represents the focus shift, and the vertical axis represents the image height, in millimeters. Figure 6 The astigmatism curve given in the middle figure shows that when the wavelength is 555.00nm, the focus shifts of the sagittal image plane and the meridional image plane are both within ±0.025 mm, indicating that the astigmatism of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0161] The horizontal axis of the distortion curve represents the distortion rate, and the vertical axis represents the image height, in millimeters. Figure 6 The distortion curve given in the middle right figure shows that the distortion rate is within ±1% when the wavelength is 555.00nm, which means that the distortion of the telephoto lens group in this embodiment is well corrected and the imaging quality is good.

[0162] according to Figure 6 It can be seen that the telephoto lens group provided in the third embodiment can achieve good imaging effect.

[0163] Embodiment 4

[0164] The structural diagram of the telephoto lens group in this embodiment is shown in FIG. Figure 7 As shown, the telephoto lens group includes a light reflecting element F, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and an infrared filter L8, which are arranged in sequence from the object side to the image side, and an aperture ST is arranged at the edge of the object side of the first lens L1.

[0165] The first lens L1 has positive refractive power, the object side surface and the image side surface of the first lens L1 are both convex at the near optical axis, the object side surface of the first lens L1 is convex at the circumference, and the image side surface is concave at the circumference.

[0166] The second lens L2 has negative refractive power, the object side surface of the second lens L2 is concave at the near optical axis, the image side surface is convex at the near optical axis, and both the object side surface and the image side surface of the second lens L2 are convex on the circumference.

[0167] The third lens L3 has positive refractive power. The object side surface of the third lens L3 is concave at the near optical axis, and the image side surface is convex at the near optical axis. The object side surface of the third lens L3 is convex on the circumference, and the image side surface is concave on the circumference.

[0168] The fourth lens L4 has negative refractive power. The object side surface and the image side surface of the fourth lens L4 are both concave surfaces at the near optical axis. The object side surface of the fourth lens L4 is convex on the circumference, and the image side surface is concave on the circumference.

[0169] The fifth lens L5 has negative refractive power. The object side surface of the fifth lens L5 is convex at the near optical axis, and the image side surface is concave at the near optical axis. Both the object side surface and the image side surface of the fifth lens L5 are concave on the circumference.

[0170] The sixth lens L6 has positive refractive power. The object side surface of the sixth lens L6 is concave at the near optical axis, and the image side surface is convex at the near optical axis. The object side surface of the sixth lens L6 is concave at the circumference, and the image side surface is convex at the circumference.

[0171] The seventh lens L7 has negative refractive power. The object side surface of the seventh lens L7 is convex at the near optical axis, and the image side surface is concave at the near optical axis. The object side surface of the seventh lens L7 is concave at the circumference, and the image side surface is convex at the circumference.

[0172] The refractive index and Abbe number of the telephoto lens group in Example 4 are both based on the light with a wavelength of 587.60 nm, and the focal length is based on the light with a wavelength of 555.00 nm. The relevant parameters of the telephoto lens group are shown in Table 10. Among them, f is the effective focal length of the telephoto lens group, FNO represents the aperture value, FOV represents the maximum field of view of the telephoto lens group, TTL is the distance from the object side of the first lens L1 to the imaging surface IMG on the optical axis, and the units of the curvature radius, thickness, and focal length are all millimeters.

[0173] Table 10

[0174]

[0175] According to the parameters in Table 10, the calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment are shown in Table 11.

[0176] Table 11

[0177]

[0178]

[0179] According to the results in Table 11, the calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment respectively satisfy the conditional expressions (1) to (9) in a one-to-one correspondence.

[0180] The cone constant K and aspheric coefficient corresponding to the surface of each lens in Example 4 are shown in Table 12.

[0181] Table 12

[0182]

[0183] Figure 8 From left to right in the figure are the spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram in the fourth embodiment.

[0184] The horizontal axis of the spherical aberration curve represents the focus offset, and the vertical axis represents the normalized field of view. Figure 8 When the wavelengths given in the left figure are 650.00nm, 610.00nm, 555.00nm, 510.00nm and 470.00nm respectively, the focus shifts of different fields of view are all within ±0.05 mm, indicating that the spherical aberration of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0185] The horizontal axis of the astigmatism curve represents the focus shift, and the vertical axis represents the image height, in millimeters. Figure 8 The astigmatism curve given in the middle figure shows that when the wavelength is 555.00nm, the focus shifts of the sagittal image plane and the meridional image plane are both within ±0.025 mm, indicating that the astigmatism of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0186] The horizontal axis of the distortion curve represents the distortion rate, and the vertical axis represents the image height, in millimeters. Figure 8 The distortion curve given in the middle right figure shows that the distortion rate is within ±1% when the wavelength is 555.00nm, which means that the distortion of the telephoto lens group in this embodiment is well corrected and the imaging quality is good.

[0187] according to Figure 8 It can be seen that the telephoto lens group provided in the fourth embodiment can achieve good imaging effects.

[0188] Embodiment 5

[0189] The structural diagram of the telephoto lens group in this embodiment is shown in FIG. Fig. 9 As shown, the telephoto lens group includes a light reflecting element F, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7 and an infrared filter L8, which are arranged in sequence from the object side to the image side, and an aperture ST is arranged at the edge of the object side of the first lens L1.

[0190] The first lens L1 has positive refractive power, the object side surface of the first lens L1 is convex at the near optical axis, the image side surface is concave at the near optical axis, the object side surface of the first lens L1 is convex at the circumference, and the image side surface is concave at the circumference.

[0191] The second lens L2 has positive refractive power, the object side surface of the second lens L2 is convex at the near optical axis, the image side surface is concave at the near optical axis, the object side surface of the second lens L2 is concave at the circumference, and the image side surface is convex at the circumference.

[0192] The third lens L3 has negative refractive power. The object side surface and the image side surface of the third lens L3 are both concave surfaces at the near optical axis. The object side surface of the third lens L3 is convex on the circumference, and the image side surface is concave on the circumference.

[0193] The fourth lens L4 has positive refractive power, the object side surface of the fourth lens L4 is convex at the near optical axis, the image side surface is concave at the near optical axis, the object side surface of the fourth lens L4 is convex on the circumference, and the image side surface is concave on the circumference.

[0194] The fifth lens L5 has negative refractive power. The object side surface of the fifth lens L5 is convex at the near optical axis, and the image side surface is concave at the near optical axis. The object side surface of the fifth lens L5 is convex on the circumference, and the image side surface is concave on the circumference.

[0195] The sixth lens L6 has positive refractive power. The object side surface of the sixth lens L6 is concave at the near optical axis, and the image side surface is convex at the near optical axis. The object side surface of the sixth lens L6 is concave at the circumference, and the image side surface is convex at the circumference.

[0196] The seventh lens L7 has negative refractive power. The object side surface of the seventh lens L7 is convex at the near optical axis, and the image side surface is concave at the near optical axis. The object side surface of the seventh lens L7 is concave at the circumference, and the image side surface is convex at the circumference.

[0197] The refractive index and Abbe number of the telephoto lens group in Example 5 are both based on the light with a wavelength of 587.60 nm, and the focal length is based on the light with a wavelength of 555.00 nm. The relevant parameters of the telephoto lens group are shown in Table 13. Among them, f is the effective focal length of the telephoto lens group, FNO represents the aperture value, FOV represents the maximum field of view of the telephoto lens group, TTL is the distance from the object side of the first lens L1 to the imaging surface IMG on the optical axis, and the units of the curvature radius, thickness, and focal length are all millimeters.

[0198] Table 13

[0199]

[0200]

[0201] According to the parameters in Table 13, the calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment are shown in Table 14.

[0202] Table 14

[0203] Conditional expression Numeric Conditional expression Numeric 43*f / (2*ImgH) 102.722 |f7 / R71| 2.786 f / EPD 2.550 (CT1+CT2+CT3+CT4) / TTL 0.226 TTL / ImgH 4.278 0.7<ΣCT / ΣAT 0.792 TTL / f 0.895 0.2<BF / TTL 0.223 |f / f4| 0.172

[0204] According to the results in Table 14, the calculation results of the numerical relationship between the relevant parameters of each lens of the telephoto lens group in this embodiment respectively satisfy conditional expressions (1) to (9) in a one-to-one correspondence.

[0205] The cone constant K and aspheric coefficient corresponding to the surface of each lens in Example 5 are shown in Table 15.

[0206] Table 15

[0207]

[0208] Fig.10 From left to right in the figure are the spherical aberration curve diagram, the astigmatism curve diagram and the distortion curve diagram in the fifth embodiment.

[0209] The horizontal axis of the spherical aberration curve represents the focus offset, and the vertical axis represents the normalized field of view. Fig.10 When the wavelengths given in the left figure are 650.00nm, 610.00nm, 555.00nm, 510.00nm and 470.00nm respectively, the focus shifts of different fields of view are all within ±0.05 mm, indicating that the spherical aberration of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0210] The horizontal axis of the astigmatism curve represents the focus shift, and the vertical axis represents the image height, in millimeters. Fig.10 The astigmatism curve given in the middle figure shows that when the wavelength is 555.00nm, the focus shifts of the sagittal image plane and the meridional image plane are both within ±0.025 mm, indicating that the astigmatism of the telephoto lens group in this embodiment is small and the imaging quality is good.

[0211] The horizontal axis of the distortion curve represents the distortion rate, and the vertical axis represents the image height, in millimeters. Fig.10 The distortion curve given in the middle right figure shows that the distortion rate is within ±1% when the wavelength is 555.00nm, which means that the distortion of the telephoto lens group in this embodiment is well corrected and the imaging quality is good.

[0212] according to Fig.10 It can be seen that the telephoto lens group provided in Example 5 can achieve good imaging effects.

[0213] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0214] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A telephoto lens set, characterized in that: The telephoto lens group includes, in order from the object side to the image side along the optical axis: A first lens having positive refractive power, wherein the object side surface of the first lens is a convex surface; a second lens having a refractive power; A third lens having a refractive power, wherein the object side surface of the third lens is a concave surface at a near optical axis; A fourth lens having a refractive power, wherein the image side surface of the fourth lens is a concave surface at a near optical axis; A fifth lens having a refractive power, wherein the image side surface of the fifth lens is a concave surface at a near optical axis; A sixth lens having a refractive power, wherein the image side surface of the sixth lens is a convex surface near the optical axis; A seventh lens having negative refractive power, wherein the image side surface of the seventh lens is concave at a position close to the optical axis, and at least one inflection point is provided on at least one of the object side surface and the image side surface of the seventh lens; The number of lenses with optical power in the telephoto lens group is seven; The telephoto lens group also satisfies the condition: 43*f / (2*ImgH)>98, wherein ImgH is half of the image height corresponding to the maximum field of view angle of the telephoto lens group, and f is the effective focal length of the telephoto lens group.

2. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group also includes an aperture stop disposed on the image side of the first lens, and the telephoto lens group satisfies the condition: f / EPD≤2.55, wherein f is the effective focal length of the telephoto lens group, and EPD is the diameter of the effective light opening of the aperture stop.

3. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group satisfies the condition: TTL / ImgH<4.5, wherein TTL is the distance from the object side of the first lens to the image plane of the telephoto lens group on the optical axis, and ImgH is half of the image height corresponding to the maximum field of view angle of the telephoto lens group.

4. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group satisfies the condition: TTL / f<0.95, wherein TTL is the distance from the object side of the first lens to the image plane of the telephoto lens group on the optical axis, and f is the effective focal length of the telephoto lens group.

5. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group satisfies the condition: |f / f4|≤2.1, wherein f is the effective focal length of the telephoto lens group, and f4 is the effective focal length of the fourth lens.

6. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group satisfies the condition: |f7 / R71|<14.8, wherein f7 is the effective focal length of the seventh lens, and R71 is the radius of curvature of the object side of the seventh lens at the optical axis.

7. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group satisfies the condition: (CT1+CT2+CT3+CT4) / TTL≤0.32, wherein CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, CT4 is the thickness of the fourth lens on the optical axis, and TTL is the distance from the object side of the first lens to the image plane of the telephoto lens group on the optical axis.

8. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group satisfies the conditional formula: 0.7 < ΣCT / ΣAT < 1.7, where ΣCT is the sum of the thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens on the optical axis, and ΣAT is the sum of the intervals of the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens on the optical axis.

9. The telephoto lens assembly according to claim 1, characterized in that: The telephoto lens group satisfies the conditional formula: 0.2 < BF / TTL < 0.37, where BF is the minimum distance parallel to the optical axis from the image side of the seventh lens to the imaging surface of the telephoto lens group, and TTL is the distance on the optical axis from the object side of the first lens to the imaging surface of the telephoto lens group.

10. A lens module, characterized in that: Comprising: The telephoto lens group according to any one of claims 1-9 above; and An image sensor, which is disposed in the imaging plane of the telephoto lens group; wherein the telephoto lens group is configured to receive light reflected by an object to be photographed and project it onto the image sensor, and the image sensor is configured to convert the light into an image signal.

11. An electronic device, characterized in that: Comprising: The lens module according to claim 10 above; and A housing, in which the lens module is mounted.

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