Large-aperture zoom lens and image pickup device

Abstract

The invention provides a large-aperture zoom lens and an image pickup device. The large-aperture zoom lens sequentially comprises a first lens group with negative focal power, a second lens group with positive focal power, a third lens group with positive focal power, an aperture diaphragm, a fourth lens group with negative focal power and a fifth lens group with positive focal power from an object side to an image side, the lens satisfies the following conditional expressions: 1.35 < = Ft / Fw < = 1.6; 0.65 < = L2 / L3 < = 1.13; l2 / L4 is greater than or equal to 0.92 and less than or equal to 1.32; 2.5 < = TTL / Ft < = 3.5; and 0.5 < = Ls / TTL < = 0.63. According to the invention, the spherical aberration is effectively inhibited and the distortion is reduced by matching the designed focal power and satisfying a specific conditional expression, and meanwhile, the characteristic of a large aperture is satisfied; moreover, the lens adopts a double-floating focusing structure, so that the aberration under different object distances can be better corrected, and the high-resolution characteristic is met.

Description

Technical Field

[0001] The present invention relates to the field of photographic technology, and in particular to a large aperture zoom lens and an image pickup device. Background Art

[0002] With the advancement of technology, micro-single cameras have gradually become the mainstream equipment in the photography industry. Thanks to the shorter flange back focus, ultra-standard lenses that surpass the big three in the SLR era have gradually appeared on the market. The larger aperture brings in more light, providing a better experience when shooting night scenes; the blurring of the large aperture also brings more atmosphere to the photos.

[0003] In the related art, the zoom lenses on the market have small apertures and low resolutions, which limits the usage scenarios of the zoom lenses. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a large aperture zoom lens and an image pickup device, aiming to solve the problem of small aperture and low resolution of the zoom lens in the related art.

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a large aperture zoom lens, which comprises, from the object side to the image side, a first lens group with negative optical power, a second lens group with positive optical power, a third lens group with positive optical power, an aperture stop, a fourth lens group with negative optical power, and a fifth lens group with positive optical power; During zooming, the second lens group and the third lens group move along the optical axis from the image side to the object side, and the fourth lens group moves along the optical axis from the object side to the image side; The large aperture zoom lens satisfies the following conditional formula: 1.35≤Ft / Fw≤1.6; 0.65≤|L2 / L3|≤1.13; 0.92≤|L2 / L4|≤1.32; 2.5≤TTL / Ft≤3.5; 0.5≤Ls / TTL≤0.63; Among them, Ft is the focal length of the large aperture zoom lens at the telephoto end, Fw is the focal length of the large aperture zoom lens at the wide-angle end, L2 is the maximum moving distance of the second lens group during the zooming process, L3 is the maximum moving distance of the third lens group during the zooming process, L4 is the maximum moving distance of the fourth lens group during the zooming process, TTL is the total optical length of the large aperture zoom lens, and Ls is the distance from the aperture stop to the image plane.

[0006] Optionally, during focusing, the second lens group moves along the optical axis from the object side to the image side, and the fourth lens group moves along the optical axis from the image side to the object side; Wherein, during the zooming process and / or the focusing process, the first lens group and the fifth lens group are fixed lens groups, and the position of the aperture stop remains unchanged.

[0007] Optionally, the large aperture zoom lens further satisfies the following conditional formula: 3.3≤|D2 / D4|≤5.5; Wherein, D2 is the maximum moving distance of the second lens group during the focusing process, and D4 is the maximum moving distance of the fourth lens group during the focusing process.

[0008] Optionally, the large aperture zoom lens further satisfies the following conditional formula: -1.35≤Fg1 / Ft≤-1; and / or, 2.5≤Fg2 / Ft≤5; and / or, 1.30≤Fg3 / Ft≤1.56; and / or, -1.45≤Fg4 / Ft≤-1.08; and / or, 0.58≤Fg5 / Ft≤0.92; Among them, Fg1 is the focal length of the first lens group, Fg2 is the focal length of the second lens group, Fg3 is the focal length of the third lens group, Fg4 is the focal length of the fourth lens group, and Fg5 is the focal length of the fifth lens group.

[0009] Optionally, the lenses of the large aperture zoom lens include at least one aspherical lens, and the lenses of the large aperture zoom lens are all glass lenses.

[0010] Optionally, the first lens group includes at least two lenses with a refractive index Nd≥1.8.

[0011] Optionally, the first lens group includes, from the object side to the image side, a first lens with negative optical power, a second lens with negative optical power, and a first optical element with positive optical power, Wherein, the first optical element includes, from the object side to the image side, a third lens with negative optical power and a fourth lens with positive optical power, and the third lens and the fourth lens are combined into a cemented lens; or, the first optical element is a third lens with positive optical power.

[0012] Optionally, the first lens group satisfies the following conditional formula: -1.3≤F01 / Ft≤-1; and / or, -6.5≤F02 / Ft≤-1.8; and / or, -6.5≤F03 / Ft≤-1.8; Among them, F01 is the focal length of the first lens, F02 is the focal length of the second lens, and F03 is the focal length of the third lens.

[0013] Optionally, the second lens group includes a fifth lens having positive optical power; or, The second lens group includes, from the object side to the image side, a fourth lens having positive refractive power and a fifth lens having negative refractive power, wherein the fourth lens and the fifth lens satisfy the following conditional formula: 25≤|Vd04-Vd05|≤35; Wherein, Vd04 is the Abbe number of the fourth lens, and Vd05 is the Abbe number of the fifth lens.

[0014] Optionally, the third lens group includes, from the object side to the image side, a sixth lens having positive refractive power and a second optical element having positive refractive power, Wherein, the second optical element includes, from the object side to the image side, a seventh lens having negative optical power and an eighth lens having positive optical power, the seventh lens and the eighth lens are combined into a cemented lens, and the seventh lens and the eighth lens satisfy the following conditional formula: 20≤|Vd07-Vd08|≤30; Wherein, Vd07 is the Abbe number of the seventh lens, Vd05 is the Abbe number of the eighth lens; or, the second optical element is a lens with positive optical power.

[0015] Optionally, the fourth lens group includes, from the object side to the image side, a third optical element with negative optical power and a fourth optical element with negative optical power; The third optical element includes, from the object side to the image side, a ninth lens having negative optical power and a tenth lens having positive optical power, and the ninth lens and the tenth lens are combined into a cemented lens; or the third optical element is a single lens having positive optical power; The fourth optical element includes, from the object side to the image side, an eleventh lens having positive refractive power and a twelfth lens having negative refractive power, the eleventh lens and the twelfth lens are combined into a cemented lens, and the eleventh lens and the twelfth lens satisfy the following conditional formula: 25≤|Vd11-Vd12|≤35; Wherein, Vd11 is the Abbe number of the eleventh lens, and Vd12 is the Abbe number of the twelfth lens; or, the fourth optical element is a lens with positive optical power.

[0016] Optionally, the fourth lens group includes a third optical element with negative optical power, and the third optical element includes, from the object side to the image side, a ninth lens with negative optical power and a tenth lens with positive optical power, and the ninth lens and the tenth lens are combined into a cemented lens; or, the third optical element is a single lens with positive optical power.

[0017] Optionally, the fifth lens group includes at least two lenses with a refractive index Nd≥1.8.

[0018] Optionally, the fifth lens group includes, from the object side to the image side, a thirteenth lens having positive power, a fourteenth lens having positive power, a fourth optical element having negative power, a seventeenth lens having negative power, and an eighteenth lens having positive power; Among them, the third optical element includes, from the object side to the image side, a fifteenth lens with positive optical power and a sixteenth lens with negative optical power, and the fifteenth lens and the sixteenth lens are combined into a cemented lens; or, the third optical element is a single lens with positive optical power.

[0019] Optionally, the thirteenth lens and the fourteenth lens satisfy the following conditional formula: 0.9≤Nd13 / Nd14≤1.1; Wherein, Nd13 is the refractive index of the thirteenth lens, and Nd14 is the refractive index of the fourteenth lens; and / or, The fifteenth lens and the sixteenth lens satisfy the following conditional formula: 25≤|Vd15-Vd16|≤40; Wherein, Vd15 is the Abbe number of the fifteenth lens, and Vd16 is the Abbe number of the sixteenth lens.

[0020] A second aspect of the present invention provides an image pickup device, comprising an image sensor and a large aperture zoom lens as described in any one of the above, wherein the image sensor is configured to receive an optical image formed by the large aperture zoom lens.

[0021] Compared with the related art, the large aperture zoom lens and image pickup device in the present invention have the following beneficial effects: the present invention optimizes the refraction and convergence of light, effectively suppresses spherical aberration and reduces distortion, and satisfies the large aperture characteristic by designing the first lens group, the second lens group, the third lens group, the fourth lens group, and the fifth lens group to have negative, positive, positive, negative, and positive focal lengths and satisfying specific conditional expressions; moreover, during the focusing process, the second lens group and the third lens group move along the optical axis from the image side to the object side, and the fourth lens group moves along the optical axis from the object side to the image side, so that the lens adopts a double floating focus structure, which can better correct aberrations at different object distances, achieve high image quality from infinity to the closest end, and satisfy high resolution characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 is a schematic structural diagram of a lens provided in Embodiment 1 of the present invention; Figure 2 a is a spherical aberration curve diagram of the lens provided in Example 1 of the present invention when it is at the infinite wide-angle end; Figure 2 b is a spherical aberration curve diagram of the lens provided in Example 1 of the present invention when it is at the intermediate end of infinity; Figure 2 c is a spherical aberration curve diagram of the lens provided in Example 1 of the present invention when it is at the infinite telephoto end; Figure 3 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 1 of the present invention at the infinite wide-angle end; Figure 4 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 1 of the present invention when it is at the intermediate end of infinity; Figure 5 Schematic diagram of field curvature and distortion of the lens provided in Embodiment 1 of the present invention when at the infinite telephoto end; Figure 6 a is a spherical aberration curve diagram of the lens provided by Example 1 of the present invention at a close object distance wide angle end; Figure 6 b is a spherical aberration curve diagram of the lens provided by Example 1 of the present invention when it is at the middle end of the close object distance; Figure 6 c is a spherical aberration curve diagram of the lens provided by Example 1 of the present invention when the lens is at the telephoto end at a close object distance; Figure 7 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 1 of the present invention at a close object distance and wide angle end; Figure 8 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 1 of the present invention at the middle end of close object distance; Fig. 9 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 1 of the present invention at the telephoto end at a close object distance; Fig.10 is a schematic structural diagram of a lens provided in Embodiment 2 of the present invention; Fig.11 a is a spherical aberration curve diagram of the lens provided in Example 2 of the present invention when it is at the infinite wide-angle end; Fig.11 b is a spherical aberration curve diagram of the lens provided in Example 2 of the present invention when it is at the intermediate end of infinity; Fig.11 c is a spherical aberration curve diagram of the lens provided in Example 2 of the present invention when at the infinite telephoto end; Fig.12 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 2 of the present invention at the infinite wide-angle end; Fig.13 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 2 of the present invention when it is at the intermediate end of infinity; Fig.14 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 2 of the present invention when at the infinite telephoto end; Fig.15 a is a spherical aberration curve diagram of the lens provided by Example 2 of the present invention at a close object distance wide angle end; Fig.15 b is a spherical aberration curve diagram of the lens provided by Embodiment 2 of the present invention when it is at the middle end of the close object distance; Fig.15 c is a spherical aberration curve diagram of the lens provided by Embodiment 2 of the present invention when at the telephoto end at a close object distance; Fig.16 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 2 of the present invention at a close object distance and wide angle end; Fig.17 Schematic diagram of field curvature and distortion of the lens provided by Embodiment 2 of the present invention when it is at the middle end of the close object distance; Fig.18 Schematic diagram of field curvature and distortion of the lens provided in Embodiment 2 of the present invention at the telephoto end at a close object distance. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention. All other embodiments obtained by ordinary technicians in the field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "circumferential", "radial" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] Example: An embodiment of the present invention provides an image pickup device, including an image sensor and a large aperture zoom lens, wherein the image sensor is configured to receive an optical image formed by the large aperture zoom lens. Specifically, light reflected by a photographed object is imaged after passing through the large aperture zoom lens and irradiated on a photosensitive surface of the image sensor, and the photosensitive surface of the image sensor receives the optical image and converts it into an image electrical signal output, thereby realizing functions such as photographing or video recording of the image pickup device; wherein the image sensor may be a photosensitive element of a camera, and the photosensitive element may be a charge coupled element, a complementary metal oxide semiconductor, etc., the camera is connected to the large aperture zoom lens, and the image sensor is located on the image plane IMG of the large aperture zoom lens.

[0028] See also Figure 1 and Fig.10, the large aperture zoom lens includes, from the object side to the image side, a first lens group G01 with negative optical power, a second lens group G02 with positive optical power, a third lens group G03 with positive optical power, an aperture stop STP, a fourth lens group G04 with negative optical power, and a fifth lens group G05 with positive optical power; during zooming, the second lens group G02 and the third lens group G03 move along the optical axis from the image side to the object side, and the fourth lens group G04 moves along the optical axis from the object side to the image side; the large aperture zoom lens satisfies the following conditional formula: 1.35≤Ft / Fw≤1.6, (1); 0.65≤|L2 / L3|≤1.13, (2); 0.92≤|L2 / L4|≤1.32, (3); 2.5≤TTL / Ft≤3.5, (4); 0.5≤Ls / TTL≤0.63, (5); Among them, Ft is the focal length of the large aperture zoom lens at the telephoto end, Fw is the focal length of the large aperture zoom lens at the wide-angle end, L2 is the maximum moving distance of the second lens group G02 during the zooming process, L3 is the maximum moving distance of the third lens group G03 during the zooming process, L4 is the maximum moving distance of the fourth lens group G04 during the zooming process, TTL is the total optical length of the large aperture zoom lens, and Ls is the distance from the aperture stop STP to the image plane IMG.

[0029] The present invention can optimize the refraction and convergence of light, effectively suppress spherical aberration and reduce distortion, and meet the large aperture characteristic by designing the first lens group G01, the second lens group G02, the third lens group G03, the fourth lens group G04, and the fifth lens group G05 to have negative, positive, positive, negative, and positive optical focal lengths and to meet specific conditional expressions; moreover, during the focusing process, the second lens group G02 and the third lens group G03 move along the optical axis from the image side to the object side, and the fourth lens group G04 moves along the optical axis from the object side to the image side, so that the lens adopts a double floating focus structure, which can better correct aberrations at different object distances, achieve high image quality from infinity to the closest end, and meet the high resolution characteristic.

[0030] The first lens group G01 has negative optical power, so that the first lens group G01 has an astigmatism effect, which can disperse the central light and the edge light of each field of view, reduce distortion, and increase luminous flux.

[0031] The second lens group G02 has positive optical power, which makes the second lens group G02 have a focusing effect. The second lens group G02 can converge the light passing through the first lens group G01, thereby not only smoothly transmitting the light collected by the first lens group G01 in front to the rear system, but also facilitating preliminary aberration correction of the incident light, thereby improving the imaging quality.

[0032] The third lens group G03 has positive optical power, so that the third lens group G03 has a focusing effect. The third lens group G03 can further converge the light passing through the second lens group G02, and can smoothly transmit the light collected by the second lens group G02 in front to the rear system.

[0033] The aperture stop STP is used to converge the light entering the lens, so as to control the amount of light entering the lens, adjust the exposure and depth of field, and achieve a large aperture. In addition, since the aperture stop STP is arranged between the third lens group G03 and the fourth lens group G04, the light entering the fourth lens group G04 can be converged to reduce the aperture of the fourth lens group G04.

[0034] The fourth lens group G04 has negative power, so that the fourth lens group G04 has an astigmatism effect, and can diverge the light emitted by the third lens group G03, and disperse the central light and the edge light of each field of view, thereby reducing distortion and increasing luminous flux.

[0035] The fifth lens group G05 has a positive refractive power, which makes the fifth lens group G05 have a focusing effect, which can make the light transition smoothly to the rear, reduce the height of the light incident to the rear, slow down the upward trend of the light, and avoid the loss of light energy caused by the excessively large angle between the main light of the chip and the light of a large field of view when reaching the imaging surface IMG, which is beneficial to improving the illumination of the edge field of view and achieving a short TTL (total optical length of the optical lens).

[0036] In addition, the second lens group G02 with positive optical power cooperates with the first lens group G01 with negative optical power, the fourth lens group G04 with negative optical power cooperates with the third lens group G03 with positive optical power, and the fifth lens group G05 with positive optical power cooperates with the fourth lens group G04 with negative optical power, which can correct the aberrations of the center and edge light of each field of view, thereby achieving high resolution of the lens and improving imaging quality.

[0037] The setting condition (1) limits the ratio of the focal length at the telephoto end of a large aperture zoom lens to the focal length at the wide-angle end of a large aperture zoom lens. If the upper limit of the range is exceeded, the zoom ratio of the lens becomes larger, but it will make various aberrations difficult to correct; if the range is lower than the lower limit of the range, the zoom ratio of the lens is too small and has no practical significance. Among them, the value of Ft / Fw can be 1.35, 1.38, 1.42, 1.5, 1.56, 1.6, etc.

[0038] Conditional equations (2) and (3) are set to limit the ratio of the maximum moving distance of the second lens group G02 during zooming to the maximum moving distance of the third lens group G03 during zooming, and the maximum moving distance of the second lens group G02 during zooming to the maximum moving distance of the fourth lens group G04 during zooming. If the upper limit of the range is exceeded, the zoom group movement stroke will be too long, the lens volume will become larger, and the excessively long stroke will also make it difficult to control the accuracy during the production process; if the range is below the lower limit, the zoom ratio is difficult to achieve, and it is not conducive to the correction of spherical aberration. Among them, the value of |L2 / L3| can be 0.65, 0.7, 0.85, 0.95, 1.1, 1.13, and the value of |L2 / L4| can be 0.92, 0.98, 1.15, 1.25, 1.3, 1.32, etc.

[0039] The conditional formula (4) limits the ratio of the total optical length of the large aperture zoom lens to the focal length of the telephoto end of the large aperture zoom lens. If the upper limit of the range is exceeded, the lens length will be too long and the portability will be reduced; if the lower limit of the range is below the lower limit, distortion and other aberrations will be difficult to correct. The value of TTL / Ft can be 2.5, 2.8, 2.95, 3.15, 3.2, 3.5, etc.

[0040] The setting condition (5) limits the ratio of the distance from the aperture stop STP to the image plane IMG to the total optical length of the large aperture zoom lens. If the upper limit of the range is exceeded, the moving space of the zoom group in front of the aperture stop STP is limited, and the aperture stop STP becomes larger, and it is easy to produce the negative effect of cutting the spot in half; if the range is lower than the lower limit, it is not conducive to the correction of spherical aberration and chromatic aberration, and the sensitivity of the assembly will be increased. Among them, the value of Ls / TTL can be 0.5, 0.52, 0.56, 0.58, 0.6, 0.63, etc.

[0041] During the focusing process, the second lens group G02 moves along the optical axis from the object side to the image side, and the fourth lens group G04 moves along the optical axis from the image side to the object side, so that the lens can achieve zooming and focusing, and it is internal zooming and internal focusing, which can better perform waterproof and dustproof treatment, and reduce the change of the lens center during zooming and focusing. In the zooming process and / or focusing process, the first lens group G01 and the fifth lens group G05 are fixed lens groups, and the position of the aperture stop STP remains unchanged.

[0042] In some embodiments, the large aperture zoom lens further satisfies the following conditional formula: 3.3≤|D2 / D4|≤5.5, (6); Among them, D2 is the maximum moving distance of the second lens group G02 during the focusing process, and D4 is the maximum moving distance of the fourth lens group G04 during the focusing process.

[0043] The above conditional formula (6) defines the ratio of the maximum moving distance of the second lens group G02 during the focusing process to the maximum moving distance of the fourth lens group G04 during the focusing process. If the ratio exceeds the upper limit of the range, the moving distance of the focusing group will be too long, which will extend the focusing time and be unfavorable for the miniaturization of the lens. If the ratio is below the lower limit of the range, the spherical aberration and distortion at close object distances will be difficult to correct, resulting in blurred and distorted images. The value of |D2 / D4| can be 3.3, 3.6, 4.2, 4.8, 5.2, 5.5, etc.

[0044] In some embodiments, the large aperture zoom lens further satisfies the following conditional formula: -1.35≤Fg1 / Ft≤-1, (7); and / or, 2.5≤Fg2 / Ft≤5, (8); and / or, 1.30≤Fg3 / Ft≤1.56, (9); and / or, -1.45≤Fg4 / Ft≤-1.08, (10); and / or, 0.58≤Fg5 / Ft≤0.92, (11); Among them, Fg1 is the focal length of the first lens group G01, Fg2 is the focal length of the second lens group G02, Fg3 is the focal length of the third lens group G03, Fg4 is the focal length of the fourth lens group G04, and Fg5 is the focal length of the fifth lens group G05.

[0045] The above conditional formula (7) defines the ratio of the focal length of the first lens group G01 to the focal length of the telephoto end of the large aperture zoom lens. If it exceeds the upper limit of the range, it is not conducive to the miniaturization of the lens; if it is lower than the lower limit of the range, the introduced distortion is difficult to correct. Among them, the value of Fg1 / Ft can be -1.35, -1.32, -1.28, -1.26, -1.2, -1, etc.

[0046] The above conditional formula (8) limits the ratio of the focal length of the second lens group G02 to the focal length of the telephoto end of the large aperture zoom lens. If it exceeds the upper limit of this range, it is not conducive to the correction of spherical aberration; if it is lower than the lower limit of this range, the moving distance during the zooming process will become larger. The values ​​of Fg2 / Ft can be 2.5, 2.5, 2.5, 2.5, 2.5, 5 The above conditional formula (9) limits the ratio of the focal length of the third lens group G03 to the focal length of the telephoto end of the large aperture zoom lens. If the ratio exceeds the upper limit of the range, it is not conducive to the correction of spherical aberration and chromatic aberration, and at the same time increases the assembly sensitivity; if the ratio is lower than the lower limit of the range, the moving distance during the zooming process will increase. The value of Fg3 / Ft can be 1.30, 1.32, 1.42, 1.48, 1.52, 1.56, etc.

[0047] The above conditional formula (10) defines the ratio of the focal length of the fourth lens group G04 to the focal length of the telephoto end of the large aperture zoom lens. If it exceeds the upper limit of the range, it is not conducive to the correction of chromatic aberration; if it is lower than the lower limit of the range, the assembly sensitivity will increase. The value of Fg4 / Ft can be -1.45, -1.40, -1.35, -1.25, -1.12, -1.08, etc.

[0048] The above conditional formula (11) defines the ratio of the focal length of the fifth lens group G05 to the focal length of the telephoto end of the large aperture zoom lens. If it exceeds the upper limit of the range, additional spherical aberration will be introduced and the assembly sensitivity will be increased; if it is lower than the lower limit of the range, it will be unfavorable to correct the field curvature and distortion. The value of Fg5 / Ft can be 0.58, 0.62, 0.73, 0.82, 0.88, 0.92, etc.

[0049] In some embodiments, the lenses of the large aperture zoom lens have at least one aspherical lens, which can reduce spherical aberration, better control the distortion of the lens while achieving high resolution of the lens, and effectively shorten the length of the system. The lenses of the large aperture zoom lens are all glass lenses, which can provide better optical performance, such as high transmittance and low dispersion.

[0050] According to actual needs, an aspheric lens can be set in the first lens group G01, or two aspheric lenses can be set in the first lens group G01, or an aspheric lens can be set in the second lens group G02 and the third lens group G03 respectively, or an aspheric lens can be set in the first lens group G01, the second lens group G02, the third lens group G03, the fourth lens group G04 and the fifth lens group G05 respectively.

[0051] It should be noted that aspherical lenses are relative to traditional spherical lenses. Traditional spherical lenses are relatively simple in design and manufacturing, but because the radius of curvature of their surfaces is constant, this will cause aberrations when light passes through the lenses, especially at the edges. Aspherical lenses modify the curvature of the lens surface so that light can pass through the lenses more evenly, thereby effectively reducing or eliminating these aberrations, making the image edges clearer, improving sharpness, and making the focus more accurate, thereby achieving high-quality imaging at large apertures. Therefore, aspherical lenses can achieve large apertures and improve sharpness. When designing lenses, aspherical lenses can also be used to reduce the number and thickness of lenses, thereby reducing the size and weight of the lenses.

[0052] In some embodiments, the first lens group G01 includes at least two lenses with a refractive index Nd ≥ 1.8, that is, the first lens group G01 includes at least two high-refractive-index lenses, which can achieve a smaller volume and higher imaging quality for the first lens group G01; at the same time, aberrations and distortions can be reduced, and imaging quality can be improved. Among them, the high-refractive-index lenses of the first lens group G01 can be two, three, four, etc., and the refractive index Nd of the high-refractive-index lenses can be 1.8, 1.82, 1.85, 1.88, 1.9, 1.95, etc.

[0053] It should be noted that the refractive index is a physical quantity that describes the degree to which the propagation direction of light changes when it propagates from one medium to another. In optical lens design, materials with a high refractive index can make the lens thinner while maintaining the same focal length and optical performance, which means that the use of high refractive index materials helps to achieve a more compact lens design and reduce the size and weight of the lens. In addition, high refractive index lenses are also beneficial for eliminating spherical aberration and correcting chromatic aberration.

[0054] The lens design of the first lens group G01 is described below with examples.

[0055] See also Figure 1 In some embodiments, the first lens group G01 includes, from the object side to the image side, a first lens L01 with negative optical power, a second lens L02 with negative optical power, and a first optical element with positive optical power, wherein the first optical element includes, from the object side to the image side, a third lens L03 with negative optical power and a fourth lens L04 with positive optical power, and the third lens L03 and the fourth lens group G04 are synthesized into a cemented lens.

[0056] By reasonably allocating the focal length of each lens of the first lens group G01, high-quality imaging effects can be achieved, including high definition, low aberration, low distortion and low dispersion; moreover, the first lens group G01 is provided with a cemented lens, which can reduce the volume and weight of the first lens group G01, realize the miniaturization of the lens, and make the lens more portable. In addition, the negative and positive focal length distribution of the two lenses of the cemented lens can effectively correct the aberrations of the lens, such as spherical aberration, coma, etc., thereby improving the sharpness and contrast of the image.

[0057] It should be noted that a cemented lens is a single lens assembly formed by bonding two or more lenses together with an optical cement. Since lenses made of different materials have different degrees of dispersion of light, by selecting a suitable combination of materials, a cemented lens can effectively correct chromatic aberration and optimize dispersion control, thereby improving the color reproduction of the image; and a cemented lens eliminates the air gap between the lenses, reduces the reflection and scattering caused by the air gap, and improves the contrast of the image.

[0058] In one implementation of the above embodiment, the first lens L01 satisfies the following conditional formula: -1.3≤F01 / Ft≤-1, (12); Wherein, F01 is the focal length of the first lens L01.

[0059] The above conditional formula (12) limits the ratio of the focal length of the first lens L01 to the focal length of the telephoto end of the large aperture zoom lens. Exceeding the upper limit will introduce excessive distortion, requiring a more complex lens group to be set up later for correction; exceeding the lower limit will require a larger aperture for the first lens L01 to collect light, resulting in a larger lens volume. Among them, the value of F01 / Ft can be -1.3, -1.28, -1.24, -1.2, -1.15, -1.

[0060] In one implementation of the above embodiment, the third lens L03 satisfies the following conditional formula: -6.5≤F03 / Ft≤-1.8, (13); Wherein, F03 is the focal length of the third lens L03.

[0061] The above conditional formula (13) limits the ratio of the focal length of the third lens L03 to the focal length of the large aperture zoom lens at the telephoto end. If the upper limit is exceeded, a large amount of spherical aberration will be introduced, which will reduce the resolution of the lens; if the lower limit is exceeded, the coma at the telephoto end cannot be corrected well. Among them, the value of F03 / Ft can be -6.5, -6.0, -4.5, -3, -2, -1.8, etc.

[0062] In one implementation of the above embodiment, the refractive index Nd of the first lens L01 and the fourth lens L04 is ≥1.8, and they are high refractive index lenses, which can ensure that the light is well processed when entering the lens system, thereby reducing imaging problems such as aberrations (such as spherical aberration, chromatic aberration, etc.) and distortion, and improving the clarity and contrast of the image.

[0063] In one implementation of the above embodiment, the Abbe number Vd of the second lens L02 and the third lens L03 is ≥60, that is, the second lens L02 and the third lens L03 are high Abbe number lenses, which can reduce chromatic aberration and avoid blur and color distortion caused by chromatic aberration, especially at the edge and wide-angle part, thereby further improving the imaging quality of the lens.

[0064] It should be noted that the Abbe number is a parameter that describes the dispersion ability of a material. A high Abbe number means that the material has less dispersion. In photographic lenses, dispersion is one of the main factors that cause color fringes to appear at the edge of the image (i.e., the "dispersion" phenomenon). Especially at large apertures, the dispersion phenomenon will be more obvious due to the large refraction angle of light in the lens. By using a lens with a high Abbe number, this dispersion phenomenon can be significantly reduced, making the lens' imaging consistency better under different colors and improving image clarity and contrast.

[0065] See also Figure 1 In one implementation of the above embodiment, the object-side surface of the first lens L01 is convex, and the image-side surface is concave, the object-side surface of the second lens L02 is convex, and the image-side surface is concave, the object-side surface of the third lens L03 is concave, and the image-side surface is concave, and the object-side surface of the fourth lens L04 is convex, and the image-side surface is concave.

[0066] It should be noted that the convex surface of the lens can converge light, collect as much light of a large field of view as possible to enter the rear optical system, increase the amount of light passing through, and collect the direction of the edge large-angle light; or, reduce the aperture of the rear group lens, smoothly transfer the light collected by the front system to the rear system, and reduce the sensitivity of the system. The concave surface of the lens can make the light diverge, so that the subsequent optical system has a larger light receiving surface, which is beneficial for the rear optical system to correct the aberration of large-angle light, reduce distortion, achieve high resolution, make the light diverge smoothly, make the turning light insensitive, and reduce the sensitivity of the lens.

[0067] Moreover, since both sides of the lens are convex, the light can be converged twice, which can not only smoothly transmit the light collected by the front system to the rear system, but also be beneficial to the preliminary aberration correction of the incident light and reduce the sensitivity of the optical lens, and can also make the light turn and gather to reduce the rear port diameter. Since both sides of the lens are concave, the light can be divergent before and after passing through the lens, and the edge light and the center light of each field of view are clearly distinguished, which is beneficial to the aberration correction of the center and edge light of each field of view, so as to reduce distortion and achieve high resolution of the optical lens.

[0068] See also Fig.10 In some embodiments, the first lens group G01 includes, from the object side to the image side, a first lens L01 with negative optical power, a second lens L02 with negative optical power, and a third lens L03 with positive optical power. The small number of lenses can greatly reduce the volume and weight of the first lens group G01, realize the miniaturization of the lens, and make the lens more portable.

[0069] In one implementation of the above embodiment, the second lens L02 satisfies the following conditional formula: -6.5≤F02 / Ft≤-1.8, (14); Wherein, F02 is the focal length of the second lens L02.

[0070] The above conditional formula (14) limits the ratio of the focal length of the second lens L02 to the focal length of the large aperture zoom lens at the telephoto end. If the upper limit is exceeded, a large amount of spherical aberration will be introduced, which will reduce the resolution of the lens; if the lower limit is exceeded, the coma at the telephoto end cannot be corrected well. Among them, the value of F02 / Ft can be -6.5, -6.0, -4.5, -3, -2, -1.8, etc.

[0071] In one implementation of the above embodiment, the refractive index Nd of the first lens L01 and the third lens L03 is greater than or equal to 1.8, and they are high refractive index lenses.

[0072] In one implementation of the above embodiment, the Abbe number Vd of the second lens L02 is ≥ 60, and the second lens L02 is a high Abbe number lens.

[0073] See also Figure 1 and Fig.10 In one implementation of the above embodiment, the object-side surface of the first lens L01 is convex and the image-side surface is concave, the object-side surface of the second lens L02 is concave and the image-side surface is concave, and the object-side surface of the third lens L03 is convex and the image-side surface is concave.

[0074] The lens design of the second lens group G02 is described below with examples.

[0075] See also Figure 1 In some embodiments, the second lens group G02 includes a fifth lens L05 having positive optical power, so that the structure of the second lens group G02 is simple, the volume and weight of the second lens group G02 can be greatly reduced, and the second lens group G02 can be quickly moved to achieve focusing or focusing.

[0076] In one implementation of the above embodiment, the fifth lens L05 has an Abbe number Vd≥60, and is a high Abbe number lens.

[0077] See also Figure 1 In one implementation of the above embodiment, the object-side surface of the fifth lens L05 is concave, and the image-side surface is convex.

[0078] See also Fig.10 In some embodiments, the second lens group G02 includes, from the object side to the image side, a fourth lens L04 having positive refractive power and a fifth lens L05 having negative refractive power, and the fourth lens L04 and the fifth lens L05 satisfy the following conditional formula: 25≤|Vd04-Vd05|≤35, (15); Wherein, Vd04 is the Abbe number of the fourth lens L04, and Vd05 is the Abbe number of the fifth lens L05.

[0079] In this embodiment, the fourth lens L04 and the fifth lens L05 cooperate with each other in positive and negative power, which can effectively eliminate aberrations and improve the resolution of the optical lens.

[0080] Moreover, the above conditional expression (15) defines the difference (absolute value) between the Abbe numbers of the fourth lens L04 and the fifth lens L05. When the conditional expression is satisfied, the chromatic aberration of the entire system can be reduced. The value of |Vd04-Vd05| can be 25, 27, 28, 32, 34, 35, etc.

[0081] See also Fig.10 In one implementation of the above embodiment, the object-side surface of the fourth lens L04 may be convex, and the image-side surface may be convex; the object-side surface of the fifth lens L05 may be convex, and the image-side surface may be concave.

[0082] The lens design of the third lens group G03 is described below with examples.

[0083] See also Figure 1 and Fig.10 In some embodiments, the third lens group G03 includes, from the object side to the image side, a sixth lens L06 having positive power and a second optical element having positive power, wherein the second optical element includes, from the object side to the image side, a seventh lens L07 having negative power and an eighth lens L08 having positive power, the seventh lens L07 and the eighth lens L08 are combined into a cemented lens, and the seventh lens L07 and the eighth lens L08 satisfy the following conditional formula: 20≤|Vd07-Vd08|≤30, (16); Wherein, Vd07 is the Abbe number of the seventh lens L07, and Vd05 is the Abbe number of the eighth lens L08.

[0084] In this embodiment, by reasonably allocating the focal length of each lens of the third lens group G03, high-quality imaging effects can be achieved, including high definition, low aberration, low distortion and low dispersion; moreover, a cemented lens is provided in the third lens group G03, which can reduce the volume and weight of the third lens group G03, and facilitate fast zooming or focusing. In addition, the negative and positive focal length distribution of the two lenses of the cemented lens can effectively correct the aberrations of the lens, such as spherical aberration, coma, etc., thereby improving the sharpness and contrast of the imaging.

[0085] Moreover, the above conditional expression (16) defines the difference (absolute value) between the Abbe numbers of the seventh lens L07 and the eighth lens L08. When the conditional expression is satisfied, the chromatic aberration of the entire system can be reduced. The value of |Vd07-Vd08| can be 20, 22, 24, 26, 28, 30, etc.

[0086] In one implementation of the above embodiment, the refractive index Nd of the seventh lens L07 is ≥ 1.8, and the seventh lens L07 is a high refractive index lens.

[0087] See also Figure 1 and Fig.10 In one implementation of the above embodiment, the object-side surface of the sixth lens L06 is convex and the image-side surface is concave, the object-side surface of the seventh lens L07 is convex and the image-side surface is concave, and the object-side surface of the eighth lens L08 is convex and the image-side surface is concave.

[0088] In some embodiments, the third lens group G03 includes, from the object side to the image side, a sixth lens L06 with positive refractive power and a second optical element with positive refractive power, wherein the second optical element is a lens with positive refractive power.

[0089] The lens design of the fourth lens group G04 is described below with examples.

[0090] See also Figure 1 In some embodiments, the fourth lens group G04 includes, from the object side to the image side, a third optical element with negative power and a fourth optical element with negative power; wherein the third optical element includes, from the object side to the image side, a ninth lens L09 with negative power and a tenth lens L10 with positive power, the ninth lens L09 and the tenth lens L10 are combined into a cemented lens; the fourth optical element includes, from the object side to the image side, an eleventh lens L11 with positive power and a twelfth lens L12 with negative power, the eleventh lens L11 and the twelfth lens L12 are combined into a cemented lens, and the eleventh lens L11 and the twelfth lens L12 satisfy the following conditional formula: 25≤|Vd11-Vd12|≤35, (17); Wherein, Vd11 is the Abbe number of the eleventh lens L11, and Vd12 is the Abbe number of the twelfth lens L12.

[0091] In this embodiment, by reasonably allocating the focal length of each lens of the fourth lens group G04, high-quality imaging effects, including high definition, low aberration, low distortion and low dispersion, can be achieved; moreover, the fourth lens group G04 is provided with two groups of cemented lenses, which can greatly reduce the volume and weight of the fourth lens group G04, and facilitate fast zooming or focusing. In addition, the positive-negative or negative-positive focal length allocation of the two lenses of the cemented lens can effectively correct the aberrations of the lens, such as spherical aberration, coma, etc., thereby improving the sharpness and contrast of the imaging.

[0092] The above conditional expression (17) defines the difference (absolute value) between the Abbe numbers of the fourth lens L04 and the fifth lens L05. When the conditional expression is satisfied, the chromatic aberration of the entire system can be reduced. The value of |Vd11-Vd12| can be 25, 27, 28, 32, 34, 35, etc.

[0093] In one implementation of the above embodiment, the refractive index Nd of the tenth lens L10 is greater than or equal to 1.8, and the tenth lens L10 is a high refractive index lens.

[0094] See also Figure 1 In one implementation of the above embodiment, the object-side surface of the ninth lens L09 is concave, and the image-side surface is concave, the object-side surface of the tenth lens L10 is convex, and the image-side surface is convex, the object-side surface of the eleventh lens L11 is concave, and the image-side surface is convex, and the object-side surface of the twelfth lens L12 is concave, and the image-side surface is convex.

[0095] In some embodiments, the fourth lens group G04 includes, from the object side to the image side, a third optical element with negative optical power and a fourth optical element with negative optical power; wherein the third optical element is a lens with positive optical power; and the fourth optical element is a lens with positive optical power.

[0096] See also Fig.10 In some embodiments, the fourth lens group G04 includes a third optical element with negative optical power, and the third optical element includes, from the object side to the image side, a ninth lens L09 with negative optical power and a tenth lens L10 with positive optical power, and the ninth lens L09 and the tenth lens L10 are combined into a cemented lens.

[0097] In this embodiment, by reasonably allocating the optical focal length of each lens of the fourth lens group G04, high-quality imaging effects including high definition, low aberration, low distortion and low dispersion can be achieved; moreover, the fourth lens group G04 is provided with two lenses which are combined into a cemented lens, which can greatly reduce the volume and weight of the fourth lens group G04, thereby facilitating rapid zooming or focusing.

[0098] In one implementation of the above embodiment, the refractive index Nd of the tenth lens L10 is greater than or equal to 1.8, and the tenth lens L10 is a high refractive index lens.

[0099] See also Fig.10 In one implementation of the above embodiment, the object-side surface of the ninth lens L09 is concave and the image-side surface is concave, and the object-side surface of the tenth lens L10 is convex and the image-side surface is convex.

[0100] In some embodiments, the fourth lens group G04 includes a third optical element with negative optical power, and the third optical element is a lens with positive optical power.

[0101] In some embodiments, the fifth lens group G05 includes at least two lenses with a refractive index Nd ≥ 1.8, that is, the fifth lens group G05 includes at least two high-refractive-index lenses, which can achieve a smaller volume and higher imaging quality for the fifth lens group G05; at the same time, it can reduce aberrations and distortions and improve imaging quality. Among them, the high-refractive-index lenses of the fifth lens group G05 can be two, three, four, etc., and the refractive index Nd of the high-refractive-index lenses can be 1.8, 1.82, 1.85, 1.88, 1.9, 1.95, etc.

[0102] The lens design of the fifth lens group G05 is described below with examples.

[0103] See also Figure 1 and Fig.10 In some embodiments, the fifth lens group G05 includes, from the object side to the image side, a thirteenth lens L13 with positive power, a fourteenth lens L14 with positive power, a fourth optical element with negative power, a seventeenth lens L17 with negative power, and an eighteenth lens L18 with positive power; wherein the third optical element includes, from the object side to the image side, a fifteenth lens L15 with positive power and a sixteenth lens L16 with negative power, and the fifteenth lens L15 and the sixteenth lens L16 are combined into a cemented lens.

[0104] In this embodiment, by reasonably allocating the power of each lens of the fifth lens group G05, high-quality imaging effects can be achieved, including high definition, low aberration, low distortion and low dispersion; and, a cemented lens is provided in the fifth lens group G05, which can reduce the volume and weight of the fifth lens group G05 and facilitate portability. In addition, the negative and positive power distribution of the two lenses of the cemented lens can effectively correct the aberrations of the lens, such as spherical aberration, coma, etc., thereby improving the sharpness and contrast of the imaging.

[0105] In one implementation of the above embodiment, the thirteenth lens L13 and the fourteenth lens L14 satisfy the following conditional formula: 0.9≤Nd13 / Nd14≤1.1, (18); Wherein, Nd13 is the refractive index of the thirteenth lens L13, and Nd14 is the refractive index of the fourteenth lens L14.

[0106] The above conditional formula (18) defines the ratio of the refractive index of the thirteenth lens L13 and the fourteenth lens L14. When the conditional formula is satisfied, the refractive index of the thirteenth lens L13 and the fourteenth lens L14 are close to each other, so that the difference in refraction of light between the two lenses is reduced, which is beneficial to reducing chromatic aberration and aberration; and it is helpful to reduce reflection and scattering of light, and further improve the imaging quality. Wherein, the value of Nd13 / Nd14 can be 25, 27, 28, 32, 34, 35, etc.

[0107] In one implementation of the above embodiment, the fifteenth lens L15 and the sixteenth lens L16 satisfy the following conditional formula: 25≤|Vd15-Vd16|≤40, (19); Wherein, Vd15 is the Abbe number of the fifteenth lens L15, and Vd16 is the Abbe number of the sixteenth lens L16.

[0108] The above conditional expression (19) defines the difference (absolute value) between the Abbe numbers of the fifteenth lens L15 and the sixteenth lens L16. When the conditional expression is satisfied, the chromatic aberration of the entire system can be reduced. The value of |Vd15-Vd16| can be 25, 28, 32, 36, 38, 40, etc.

[0109] In one implementation of the above embodiment, the refractive index Nd of the sixteenth lens L16, the seventeenth lens L17 and the eighteenth lens L18 is ≥1.8.

[0110] See also Figure 1 and Fig.10 In one implementation of the above embodiment, the object-side surface of the thirteenth lens L13 is convex, and the image-side surface is convex, the object-side surface of the fourteenth lens L14 is convex, and the image-side surface is convex, the object-side surface of the fifteenth lens L15 is convex, and the image-side surface is convex, the image-side surface of the sixteenth lens L16 is concave, and the object-side surface is concave, the object-side surface of the seventeenth lens L17 is concave, and the image-side surface is concave, and the object-side surface of the eighteenth lens L18 is convex, and the image-side surface is concave.

[0111] In some embodiments, the fifth lens group G05 includes, from the object side to the image side, a thirteenth lens L13 with positive optical power, a fourteenth lens L14 with positive optical power, a fourth optical element with negative optical power, a seventeenth lens L17 with negative optical power, and an eighteenth lens L18 with positive optical power; wherein the third optical element is a lens with positive optical power.

[0112] See also Figure 1 and Fig.10In some embodiments, a parallel glass plate GL configured by a filter is arranged between the last lens of the fifth lens group G05 and the image plane IMG. The parallel glass plate GL is used to filter light to improve the image quality. Specifically, it can absorb or reflect light of certain wavelengths to eliminate or reduce interference factors such as chromatic aberration and stray light, thereby improving the contrast and clarity of the image.

[0113] Specific embodiments of a large aperture zoom lens are provided below.

[0114] Example 1 See also Figure 1 , Figure 1 : is a schematic diagram of the structure of the large aperture zoom lens provided in this embodiment. The lens includes, from the object side to the image side, a first lens L01, a second lens L02, a third lens L03, a fourth lens L04, a fifth lens L05, a sixth lens L06, a seventh lens L07, an eighth lens L08, an aperture stop STP, a ninth lens L09, a tenth lens L10, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L13, a fourteenth lens L14, a fifteenth lens L15, a sixteenth lens L16, a seventeenth lens L17, and an eighteenth lens L18.

[0115] The first lens L01 has negative focal power, the second lens L02 has negative focal power, the third lens L03 has negative focal power, the fourth lens L04 has positive focal power, the fifth lens L05 has positive focal power, the sixth lens L06 has positive focal power, the seventh lens L07 has negative focal power, the eighth lens L08 has positive focal power, the ninth lens L09 has negative focal power, the tenth lens L10 has positive focal power, the eleventh lens L11 has positive focal power, the twelfth lens L12 has negative focal power, the thirteenth lens L13 has positive focal power, the fourteenth lens L14 has positive focal power, the fifteenth lens L15 has positive focal power, the sixteenth lens L16 has negative focal power, the seventeenth lens L17 has negative focal power, and the eighteenth lens L18 has positive focal power.

[0116] The object side surface of the first lens L01 is convex, and the image side surface is concave, the object side surface of the second lens L02 is convex, and the image side surface is concave, the object side surface of the third lens L03 is concave, and the image side surface is concave, the object side surface of the fourth lens L04 is convex, and the image side surface is concave, the object side surface of the fifth lens L05 is concave, and the image side surface is convex, the object side surface of the sixth lens L06 is convex, and the image side surface is concave, the object side surface of the seventh lens L07 is convex, and the image side surface is concave, the object side surface of the eighth lens L08 is convex, and the image side surface is concave, the object side surface of the ninth lens L09 is concave, and the image side surface is concave, and the tenth lens The object side surface of L10 is convex, and the image side surface is convex, the object side surface of the eleventh lens L11 is concave, and the image side surface is convex, the object side surface of the twelfth lens L12 is concave, and the image side surface is convex, the object side surface of the thirteenth lens L13 is convex, and the image side surface is convex, the object side surface of the fourteenth lens L14 is convex, and the image side surface is convex, the object side surface of the fifteenth lens L15 is convex, and the image side surface is convex, the image side surface of the sixteenth lens L16 is concave, and the object side surface is concave, the object side surface of the seventeenth lens L17 is concave, and the image side surface is concave, and the object side surface of the eighteenth lens L18 is convex, and the image side surface is concave.

[0117] The third lens L03 and the fourth lens group G04 form a cemented lens, the seventh lens L07 and the eighth lens L08 form a cemented lens, the ninth lens L09 and the tenth lens L10 form a cemented lens, the eleventh lens L11 and the twelfth lens L12 form a cemented lens, and the fifteenth lens L15 and the sixteenth lens L16 form a cemented lens.

[0118] In this embodiment, the numerical data of the large aperture zoom lens are shown in Table 1 to Table 4: Table 1

[0119] The surface number indicates the surface number of each lens from the object side to the image side.

[0120] It can be seen from Table 1 that the refractive index Nd01 of the first lens L01 is 1.951498, the refractive index Nd04 of the fourth lens L04 is 2.0033, the refractive index Nd07 of the seventh lens L07 is 2.0006, the refractive index Nd10 of the tenth lens L10 is 1.945950, the refractive index Nd16 of the sixteenth lens L16 is 1.808820, the refractive index Nd17 of the seventeenth lens L17 is 1.808820, and the refractive index Nd18 of the eighteenth lens L18 is 1.945950, so that the first lens L01, the fourth lens L04, the seventh lens L07, the tenth lens L10, the sixteenth lens L16, the seventeenth lens L17 and the eighteenth lens L18 are all high refractive index lenses.

[0121] It can be seen from Table 1 that the Abbe number Vd02 of the second lens L02 is 67.022, the Abbe number Vd03 of the third lens L03 is 70.4412, and the Abbe number Vd05 of the fifth lens L05 is 81.5596, so that the second lens L02, the third lens L03 and the fifth lens L05 are all high Abbe number lenses.

[0122] It can be seen from Table 1 that the seventeenth lens L17 is an aspherical lens.

[0123] Table 2

[0124] Table 3

[0125] Table 4

[0126] Among them, the aspheric surface in Table 4 is expressed by the following mathematical formula: ; Among them, Z is the direction of the optical axis, R is the radius of curvature of the surface, Y is the height of the surface perpendicular to the optical axis, K is the cone coefficient, and A4, A6, A8, A10, and A12 are aspheric coefficients.

[0127] See also Figures 2 to 5 , Figure 2 a is the spherical aberration curve of the lens at the infinite wide-angle end. Figure 2 b is the spherical aberration curve when the lens is at the middle end of infinity. Figure 2 Spherical aberration curve of c lens at infinity telephoto end, Figure 3 This is a schematic diagram of field curvature and distortion when the lens is at the infinite wide-angle end. Figure 4 This is a schematic diagram of field curvature and distortion when the lens is at the middle end of infinity. Figure 5 This is a schematic diagram of field curvature and distortion when the lens is at infinity telephoto end.

[0128] See also Figures 6 to 9 , Figure 6 a is the spherical aberration curve of the lens at the wide-angle end with a close object distance. Figure 6 b is the spherical aberration curve of the lens at the middle end of the close object distance. Figure 6 Spherical aberration curve of c lens at the telephoto end with close object distance, Figure 7 This is a schematic diagram of the field curvature and distortion of the lens at the wide-angle end at a close object distance. Figure 8 This is a diagram of the field curvature and distortion of the lens at the middle end of the close object distance. Fig. 9 This is a schematic diagram of the field curvature and distortion of the lens when it is at the telephoto end at a close object distance.

[0129] Depend on Figures 2 to 9 It can be seen that the lens of Example 1 has a good imaging effect.

[0130] It should be noted that the spherical aberration curve diagram represents the spherical aberration curve when the aperture number is 1.8, wherein the F line, d line, and C line represent the spherical aberration at a wavelength of 486nm, a wavelength of 587nm, and a wavelength of 656nm, respectively. The horizontal axis represents the spherical aberration value, and the vertical axis represents the field of view. The field curvature curve diagram represents the field curvature curve when the half field angle ω is 32.2°, 26.0°, and 22.5°, wherein the dotted line T represents the value of the chief ray D line at the sagittal image plane IMG, and the solid line S represents the value of the chief ray D line at the meridional image plane IMG. The horizontal axis represents the field curvature value, and the vertical axis represents the field of view. The distortion curve diagram represents the distortion curve when the half field angle ω is 32.2°, 26.0°, and 22.5°, wherein the horizontal axis represents the distortion value, and the vertical axis represents the field of view.

[0131] It should be understood that the above descriptions of various spherical aberrations, field curvatures, and distortion curves are the same as those in other embodiments and will not be repeated in detail below.

[0132] Example 2 See also Fig.10 , Fig.10 : is a schematic diagram of the structure of the large aperture zoom lens provided in this embodiment. The lens includes, from the object side to the image side, a first lens L01, a second lens L02, a third lens L03, a fourth lens L04, a fifth lens L05, a sixth lens L06, a seventh lens L07, an eighth lens L08, an aperture stop STP, a ninth lens L09, a tenth lens L10, a thirteenth lens L13, a fourteenth lens L14, a fifteenth lens L15, a sixteenth lens L16, a seventeenth lens L17, and an eighteenth lens L18.

[0133] The first lens L01 has negative focal power, the second lens L02 has negative focal power, the third lens L03 has positive focal power, the fourth lens L04 has positive focal power, the fifth lens L05 has negative focal power, the sixth lens L06 has positive focal power, the seventh lens L07 has negative focal power, the eighth lens L08 has positive focal power, the ninth lens L09 has negative focal power, the tenth lens L10 has positive focal power, the thirteenth lens L13 has positive focal power, the fourteenth lens L14 has positive focal power, the fifteenth lens L15 has positive focal power, the sixteenth lens L16 has negative focal power, the seventeenth lens L17 has negative focal power, and the eighteenth lens L18 has positive focal power.

[0134] The object side surface of the first lens L01 is convex, and the image side surface is concave; the object side surface of the second lens L02 is concave, and the image side surface is concave; the object side surface of the third lens L03 is convex, and the image side surface is concave; the object side surface of the fourth lens L04 is convex, and the image side surface is convex; the object side surface of the fifth lens L05 is convex, and the image side surface is concave; the object side surface of the sixth lens L06 is convex, and the image side surface is concave; the object side surface of the seventh lens L07 is convex, and the image side surface is concave; the object side surface of the eighth lens L08 is convex, and the image side surface is convex; and the ninth lens L09 is convex. The object side surface of the lens L09 is concave, and the image side surface is concave, the object side surface of the tenth lens L10 is convex, and the image side surface is convex, the object side surface of the thirteenth lens L13 is convex, and the image side surface is convex, the object side surface of the fourteenth lens L14 is convex, and the image side surface is convex, the object side surface of the fifteenth lens L15 is convex, and the image side surface is convex, the image side surface of the sixteenth lens L16 is concave, and the object side surface is concave, the object side surface of the seventeenth lens L17 is concave, and the image side surface is concave, and the object side surface of the eighteenth lens L18 is convex, and the image side surface is concave.

[0135] The seventh lens L07 and the eighth lens L08 are combined into a cemented lens, the ninth lens L09 and the tenth lens L10 are combined into a cemented lens, and the fifteenth lens L15 and the sixteenth lens L16 are combined into a cemented lens.

[0136] In this embodiment, the numerical data of the large aperture zoom lens are shown in Table 5 to Table 8: Table 5

[0137] The surface number indicates the surface number of each lens from the object side to the image side.

[0138] It can be seen from Table 5 that the refractive index Nd01 of the first lens L01 is 1.903660, the refractive index Nd03 of the third lens L03 is 2.0017, the refractive index Nd07 of the seventh lens L07 is 2.0033, the refractive index Nd10 of the tenth lens L10 is 1.945950, the refractive index Nd16 of the sixteenth lens L16 is 1.805180, the refractive index Nd17 of the seventeenth lens L17 is 1.808820, and the refractive index Nd18 of the eighteenth lens L18 is 1.945950, so that the first lens L01, the third lens L03, the seventh lens L07, the tenth lens L10, the sixteenth lens L16, the seventeenth lens L17 and the eighteenth lens L18 are all high refractive index lenses.

[0139] It can be seen from Table 5 that the Abbe number Vd02 of the second lens L02 is 95.10, which makes the second lens L02 a high Abbe number lens.

[0140] It can be seen from Table 5 that the seventeenth lens L17 is an aspherical lens.

[0141] Table 6

[0142] Table 7

[0143] Table 8

[0144] See also Figures 11 to 13 , Fig.11 a is the spherical aberration curve of the lens at the infinite wide-angle end. Fig.11 b is the spherical aberration curve when the lens is at the middle end of infinity. Fig.11 c is the spherical aberration curve of the lens at infinity telephoto end, Fig.12 This is a schematic diagram of field curvature and distortion when the lens is at the infinite wide-angle end. Fig.13 This is a schematic diagram of field curvature and distortion when the lens is at the middle end of infinity. Fig.14 This is a schematic diagram of field curvature and distortion when the lens is at infinity telephoto end.

[0145] See also Figures 15 to 18 , Fig.15 a is the spherical aberration curve of the lens at the wide-angle end with a close object distance. Fig.15 b is the spherical aberration curve of the lens at the middle end of the close object distance. Fig.15 c is the spherical aberration curve of the lens at the telephoto end of the close object distance. Fig.16 This is a schematic diagram of the field curvature and distortion of the lens at the wide-angle end at a close object distance. Fig.17 This is a diagram of the field curvature and distortion of the lens at the middle end of the close object distance. Fig.18 This is a schematic diagram of the field curvature and distortion of the lens when it is at the telephoto end at a close object distance.

[0146] Depend on Figures 15 to 18 It can be seen that the lens of Example 2 has a good imaging effect.

[0147] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A large aperture zoom lens, characterized in that: The lens includes, from the object side to the image side, a first lens group having negative power, a second lens group having positive power, a third lens group having positive power, an aperture stop, a fourth lens group having negative power, and a fifth lens group having positive power; During zooming, the second lens group and the third lens group move along the optical axis from the image side to the object side, and the fourth lens group moves along the optical axis from the object side to the image side; The large aperture zoom lens satisfies the following conditional formula: 1.35≤Ft / Fw≤1.6; 0.65≤|L2 / L3|≤1.13; 0.92≤|L2 / L4|≤1.32; 2.5≤TTL / Ft≤3.5; 0.5≤Ls / TTL≤0.63; Among them, Ft is the focal length of the large aperture zoom lens at the telephoto end, Fw is the focal length of the large aperture zoom lens at the wide-angle end, L2 is the maximum moving distance of the second lens group during the zooming process, L3 is the maximum moving distance of the third lens group during the zooming process, L4 is the maximum moving distance of the fourth lens group during the zooming process, TTL is the total optical length of the large aperture zoom lens, and Ls is the distance from the aperture stop to the image plane.

2. The large aperture zoom lens according to claim 1, characterized in that: During focusing, the second lens group moves along the optical axis from the object side to the image side, and the fourth lens group moves along the optical axis from the image side to the object side; Wherein, during the zooming process and / or the focusing process, the first lens group and the fifth lens group are fixed lens groups, and the position of the aperture stop remains unchanged.

3. The large aperture zoom lens according to claim 2, characterized in that: The large aperture zoom lens also satisfies the following conditional formula: 3.3≤|D2 / D4|≤5.5; Wherein, D2 is the maximum moving distance of the second lens group during the focusing process, and D4 is the maximum moving distance of the fourth lens group during the focusing process.

4. The large aperture zoom lens according to claim 1, characterized in that: The large aperture zoom lens also satisfies the following conditional formula: -1.35≤Fg1 / Ft≤-1; and / or, 2.5≤Fg2 / Ft≤5; and / or, 1.30≤Fg3 / Ft≤1.56; and / or, -1.45≤Fg4 / Ft≤-1.08; and / or, 0.58≤Fg5 / Ft≤0.92; Among them, Fg1 is the focal length of the first lens group, Fg2 is the focal length of the second lens group, Fg3 is the focal length of the third lens group, Fg4 is the focal length of the fourth lens group, and Fg5 is the focal length of the fifth lens group.

5. The large aperture zoom lens according to claim 1, characterized in that: The lenses of the large aperture zoom lens include at least one aspherical lens, and the lenses of the large aperture zoom lens are all glass lenses.

6. The large aperture zoom lens according to claim 1, characterized in that: The first lens group includes at least two lenses with a refractive index Nd≥1.

8.

7. The large aperture zoom lens according to claim 1, characterized in that: The first lens group includes, from the object side to the image side, a first lens having negative power, a second lens having negative power, and a first optical element having positive power. Wherein, the first optical element includes, from the object side to the image side, a third lens with negative optical power and a fourth lens with positive optical power, and the third lens and the fourth lens are combined into a cemented lens; or, the first optical element is a third lens with positive optical power.

8. The large aperture zoom lens according to claim 7, characterized in that: The first lens group satisfies the following conditional formula: -1.3≤F01 / Ft≤-1; and / or, -6.5≤F02 / Ft≤-1.8; and / or, -6.5≤F03 / Ft≤-1.8; Among them, F01 is the focal length of the first lens, F02 is the focal length of the second lens, and F03 is the focal length of the third lens.

9. The large aperture zoom lens according to claim 1, characterized in that: The second lens group includes a fifth lens having positive refractive power; or, The second lens group includes, from the object side to the image side, a fourth lens having positive refractive power and a fifth lens having negative refractive power, wherein the fourth lens and the fifth lens satisfy the following conditional formula: 25≤|Vd04-Vd05|≤35; Wherein, Vd04 is the Abbe number of the fourth lens, and Vd05 is the Abbe number of the fifth lens.

10. The large aperture zoom lens according to claim 1, characterized in that: The third lens group includes, from the object side to the image side, a sixth lens having positive refractive power and a second optical element having positive refractive power. Wherein, the second optical element includes, from the object side to the image side, a seventh lens having negative optical power and an eighth lens having positive optical power, the seventh lens and the eighth lens are combined into a cemented lens, and the seventh lens and the eighth lens satisfy the following conditional formula: 20≤|Vd07-Vd08|≤30; Wherein, Vd07 is the Abbe number of the seventh lens, Vd05 is the Abbe number of the eighth lens; or, the second optical element is a lens with positive optical power.

11. The large aperture zoom lens according to claim 1, characterized in that: The fourth lens group includes, from the object side to the image side, a third optical element having negative optical power and a fourth optical element having negative optical power; The third optical element includes, from the object side to the image side, a ninth lens having negative optical power and a tenth lens having positive optical power, and the ninth lens and the tenth lens are combined into a cemented lens; or the third optical element is a single lens having positive optical power; The fourth optical element includes, from the object side to the image side, an eleventh lens having positive refractive power and a twelfth lens having negative refractive power, the eleventh lens and the twelfth lens are combined into a cemented lens, and the eleventh lens and the twelfth lens satisfy the following conditional formula: 25≤|Vd11-Vd12|≤35; Wherein, Vd11 is the Abbe number of the eleventh lens, and Vd12 is the Abbe number of the twelfth lens; or, the fourth optical element is a lens with positive optical power.

12. The large aperture zoom lens according to claim 1, characterized in that: The fourth lens group includes a third optical element with negative optical power, and the third optical element includes, from the object side to the image side, a ninth lens with negative optical power and a tenth lens with positive optical power, and the ninth lens and the tenth lens are combined into a cemented lens; or, the third optical element is a single lens with positive optical power.

13. The large aperture zoom lens according to any one of claims 1 to 12, characterized in that: The fifth lens group includes at least two lenses with a refractive index Nd≥1.

8.

14. The large aperture zoom lens according to claim 13, characterized in that: The fifth lens group includes, from the object side to the image side, a thirteenth lens having positive power, a fourteenth lens having positive power, a fourth optical element having negative power, a seventeenth lens having negative power, and an eighteenth lens having positive power; Among them, the third optical element includes, from the object side to the image side, a fifteenth lens with positive optical power and a sixteenth lens with negative optical power, and the fifteenth lens and the sixteenth lens are combined into a cemented lens; or, the third optical element is a single lens with positive optical power.

15. The large aperture zoom lens according to claim 14, characterized in that: The thirteenth lens and the fourteenth lens satisfy the following conditional formula: 0.9≤Nd13 / Nd14≤1.1; Wherein, Nd13 is the refractive index of the thirteenth lens, and Nd14 is the refractive index of the fourteenth lens; and / or, The fifteenth lens and the sixteenth lens satisfy the following conditional formula: 25≤|Vd15-Vd16|≤40; Wherein, Vd15 is the Abbe number of the fifteenth lens, and Vd16 is the Abbe number of the sixteenth lens.

16. An image pickup device, characterized in that: The invention comprises an image sensor and the large aperture zoom lens as claimed in any one of claims 1 to 15, wherein the image sensor is configured to receive an optical image formed by the large aperture zoom lens.

Images