Large-aperture internal focusing type long-focus photographic lens and photographic device

Abstract

The invention discloses a large-aperture internal focusing type long-focus photographic lens and a photographic device. The lens sequentially comprises a first lens group with positive focal power, an aperture diaphragm, a second lens group with positive focal power and a third lens group with negative focal power from an object side to an image side, in the focusing process, the second lens group moves along the optical axis, and the first lens group and the third lens group remain unchanged relative to the position of the image plane. The first lens group, the second lens group and the third lens group satisfy the following conditional expressions: 1 < = F1 / F < = 3; 0.5 < = F2 / F < = 2; -6 < = F3 / F < =-3; wherein F1 represents the composite focal length of the first lens group, F2 represents the composite focal length of the second lens group, F3 represents the composite focal length of the third lens group, and F represents the focal length of the photographic lens. The large-aperture internal focusing type long-focus photographic lens provided by the technical scheme of the invention is beneficial to optimization of optical performance, focusing mechanism, balance of positive and negative focal power and simplification of design and manufacturing of the lens.

Description

Technical Field

[0001] The present application relates to the field of camera technology, and in particular to a large aperture, inner-focus telephoto camera lens and a photographic device. Background Art

[0002] In recent years, the demand for mirrorless cameras in the photography market has been expanding rapidly. Compared with SLR cameras, which are large in size and less portable, mirrorless cameras are small, light and portable because they do not have a reflector component. At the same time, thanks to the increasing development and maturity of high-precision CMOS chips, the resolution of cameras is also increasing day by day, making mirrorless cameras also have excellent high-quality imaging quality.

[0003] Large aperture and long focal length photography lenses have the characteristics of large aperture, high sharpness, good blur effect, etc. However, existing large aperture and long focal length photography lenses have less than ideal processing effects on image clarity, contrast and color performance.

[0004] Therefore, it is necessary to improve the existing large aperture and long focal length photographic lens. Summary of the Invention

[0005] The present application provides a large aperture inner focus telephoto lens, which aims to solve the problem that the optical performance of existing large aperture long focal length photographic lenses is not ideal.

[0006] To achieve the above objectives, the present application proposes a large aperture inner focus telephoto lens. The large aperture inner focus telephoto lens comprises, from the object side to the image side, a first lens group with positive optical power, an aperture stop, a second lens group with positive optical power, and a third lens group with negative optical power. During focusing, the second lens group moves along the optical axis, while the first lens group and the third lens group remain in position relative to the image plane.

[0007] The first lens group, the second lens group, and the third lens group satisfy the following conditional formula:

[0008] 1≤F1 / F≤3, (1);

[0009] 0.5≤F2 / F≤2, (2);

[0010] -6≤F3 / F≤-3, (3);

[0011] Among them, F1 represents the composite focal length of the first lens group, F2 represents the composite focal length of the second lens group, F3 represents the composite focal length of the third lens group, and F represents the focal length of the photographic lens.

[0012] In some embodiments, the first lens group includes, from the object side to the image side, a first lens with positive refractive power and at least one lens with positive refractive power and an Abbe number Vd≥60, and the refractive index Nd1 of the first lens is ≥1.8.

[0013] In some embodiments, the first lens group includes a first cemented lens group consisting of a positive power lens and a negative power lens, and the number of the first cemented lens group is at least one.

[0014] In some embodiments, the first lens group includes, from the object side to the image side, a first lens having positive refractive power, a second lens having positive refractive power, a third lens having positive refractive power, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having negative refractive power;

[0015] The Abbe numbers Vd of the second lens, the third lens, and the fourth lens are ≥60; the fourth lens and the fifth lens are combined to form the first cemented lens group.

[0016] In some embodiments, the fourth lens and the fifth lens satisfy the following conditional formula:

[0017] |Vd4-Vd5|≥30, (4);

[0018] Wherein, Vd4 is the Abbe number of the fourth lens in the first lens group with respect to the light with a wavelength of 587.6 nm; Vd5 is the Abbe number of the fifth lens in the first lens group with respect to the light with a wavelength of 587.6 nm.

[0019] In some embodiments, the second lens group includes, from the object side to the image side, a second cemented lens group with negative optical power and an aspheric lens with positive optical power; the surface of the lens close to the aperture stop side in the second cemented lens group is bent toward the aperture stop.

[0020] In some embodiments, the second lens group includes, from the object side to the image side, a seventh lens having negative refractive power, an eighth lens having positive refractive power, and a ninth lens having positive refractive power;

[0021] The seventh lens and the eighth lens are combined to form the second cemented lens group; the refractive index Nd8 of the eighth lens is ≥1.8; and the ninth lens is an aspherical lens.

[0022] In some embodiments, the seventh lens and the eighth lens satisfy the following conditional formula:

[0023] |Nd7-Nd8|≥0.2, (5);

[0024] Wherein, Nd7 is the refractive index of the seventh lens element in the second lens group with respect to the light with a wavelength of 587.6 nm; Nd8 is the refractive index of the eighth lens element in the second lens group with respect to the light with a wavelength of 587.6 nm.

[0025] In some embodiments, the third lens group includes, from the object side to the image side, a tenth lens having positive refractive power, an eleventh lens having negative refractive power, a twelfth lens having positive refractive power, a thirteenth lens having positive refractive power, a fourteenth lens having negative refractive power, and a fifteenth lens having negative refractive power;

[0026] The tenth lens and the eleventh lens are combined to form a third cemented lens group with negative optical power, and the thirteenth lens and the fourteenth lens are combined to form a fourth cemented lens group with negative optical power.

[0027] In some embodiments, the third lens group includes, from the object side to the image side, a tenth lens having positive refractive power, an eleventh lens having negative refractive power, a twelfth lens having positive refractive power, a thirteenth lens having negative refractive power, a fourteenth lens having positive refractive power, and a fifteenth lens having negative refractive power;

[0028] The tenth lens and the eleventh lens are combined to form a third cemented lens group with negative optical power, and the thirteenth lens and the fourteenth lens are combined to form a fourth cemented lens group with negative optical power.

[0029] In some embodiments, the third lens group includes, from the object side to the image side, a tenth lens having negative refractive power, an eleventh lens having positive refractive power, a twelfth lens having positive refractive power, a thirteenth lens having negative refractive power, a fourteenth lens having positive refractive power, and a fifteenth lens having negative refractive power.

[0030] The tenth lens and the twelfth lens are combined into a third cemented lens with positive power, and the twelfth lens and the thirteenth lens are combined into a fourth cemented lens group with negative power.

[0031] The present application also provides a photographic device, which includes an image sensor and the aforementioned large aperture inner-focus telephoto photographic lens, wherein the image sensor and the large aperture inner-focus telephoto photographic lens are detachably connected.

[0032] The technical solution of the present application proposes a large aperture inner focus telephoto photographic lens. The large aperture inner focus telephoto photographic lens includes three lens groups, wherein the first lens group and the third lens group remain unchanged relative to the image plane, and the second lens group is a focusing lens group; the first lens group, the second lens group, and the third lens group satisfy the following conditions: 1≤F1 / F≤3; 0.5≤F2 / F≤2; -6≤F3 / F≤-3; wherein F1 represents the composite focal length of the first lens group, F2 represents the composite focal length of the second lens group, F3 represents the composite focal length of the third lens group, and F represents the focal length of the photographic lens. The technical solution of the present application forms a large aperture inner focus telephoto photographic lens through a reasonable configuration and combination of lens groups, and further provides the relationship between the focal length of each lens group and the focal length of the entire photographic lens. Such a design helps to optimize the optical performance of the lens, the focusing mechanism, the balance of positive and negative optical power, and the simplification of design and production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0034] Figure 1 A schematic structural diagram of embodiment 1 of the present invention is shown;

[0035] Figure 2 A schematic diagram showing spherical aberration of Example 1 of the present invention when in focus at infinity;

[0036] Figure 3 Schematic diagram showing field curvature and distortion of embodiment 1 of the present invention when focusing at infinity;

[0037] Figure 4 A schematic diagram showing spherical aberration of Example 1 of the present invention at the minimum focusing distance;

[0038] Figure 5 A schematic diagram showing field curvature and distortion at the minimum focusing distance of Example 1 of the present invention is shown;

[0039] Figure 6 A schematic structural diagram of embodiment 2 of the present invention is shown;

[0040] Figure 7 A schematic diagram showing spherical aberration of Example 2 of the present invention when in focus at infinity;

[0041] Figure 8 A schematic diagram showing field curvature and distortion of embodiment 2 of the present invention when focusing at infinity;

[0042] Figure 9 A schematic diagram showing spherical aberration of Example 2 of the present invention at the minimum focusing distance;

[0043] Figure 10 A schematic diagram showing field curvature and distortion of Example 2 of the present invention at the minimum focusing distance is shown;

[0044] Figure 11 A schematic structural diagram of embodiment 3 of the present invention is shown;

[0045] Figure 12 A schematic diagram showing spherical aberration of Example 3 of the present invention when in focus at infinity;

[0046] Figure 13 Schematic diagram showing field curvature and distortion of embodiment 3 of the present invention when focusing at infinity;

[0047] Figure 14 A schematic diagram showing spherical aberration of Example 3 of the present invention at the minimum focusing distance;

[0048] Figure 15 A schematic diagram showing field curvature and distortion of embodiment 3 of the present invention at the minimum focusing distance is shown. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0051] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element.

[0052] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0053] See Figure 1 As shown, the present application proposes a large aperture inner focusing telephoto lens. The large aperture inner focusing telephoto lens comprises, from the object side to the image side, a first lens group G1 with positive focal power, an aperture stop STP, a second lens group G2 with positive focal power, and a third lens group G3 with negative focal power. During the focusing process, the second lens group G2 moves along the optical axis, while the positions of the first lens group G1 and the third lens group G3 relative to the image plane remain unchanged. The first lens group G1, the second lens group G2, and the third lens group G3 satisfy the following conditional formula:

[0054] 1≤F1 / F≤3, (1);

[0055] 0.5≤F2 / F≤2, (2);

[0056] -6≤F3 / F≤-3, (3);

[0057] Wherein, F1 represents the composite focal length of the first lens group G1, F2 represents the composite focal length of the second lens group G2, F3 represents the composite focal length of the third lens group G3, and F represents the focal length of the photographic lens.

[0058] Among them, the first lens group G1 includes, from the object side to the image side, a first lens L01 with positive refractive power and at least one lens with positive refractive power and an Abbe number Vd≥60, and the refractive index Nd1 of the first lens L01 is ≥1.8; the second lens group G2 includes an aspheric lens with positive refractive power.

[0059] The technical solution of the present application further sets the first lens group G1, the second lens group G2 and the third lens group G3 to meet a specific proportional relationship. This design can enable the lens to adapt to different application scenarios and needs.

[0060] Specifically, the first lens group G1 makes a moderate contribution to the overall focal length, meaning the lens's light-gathering ability is balanced, neither too strong nor too weak. This design helps maintain image clarity and contrast, particularly at varying shooting distances. If the (F1 / F) ratio is too large, the lens's light-gathering ability will be too strong, resulting in excessive spherical aberration and chromatic aberration when shooting at close range, affecting image clarity and color accuracy. If the (F1 / F) ratio is too small, the lens's light-gathering ability will be weak, making it difficult to achieve sufficient clarity and contrast when shooting at long distances.

[0061] The contribution of the second lens group G2 to the overall focal length is within a reasonable range. This design allows for sufficient flexibility during focusing, adapting to varying shooting distances. It also helps further optimize image quality, minimizing aberrations and other optical defects. If the (F2 / F) ratio is too large, the lens will be overly sensitive during focusing, causing even small changes in focus to cause significant changes in focal length, increasing operational difficulty. If the (F2 / F) ratio is too small, the lens will lack sufficient flexibility during focusing, making it difficult to adapt to varying shooting distances.

[0062] The third lens group G3 has negative power to correct aberrations and control the field of view. When the F3 / F ratio is between -6 and -3, the negative contribution of the third lens group G3 to the overall focal length is moderate. This design helps balance the optical performance of the lens, reducing distortion and other aberrations, thereby improving image quality.

[0063] The Abbe number, also known as the dispersion coefficient, is a physical quantity that describes the ability of a lens material to disperse light. Lens materials with high Abbe numbers have lower dispersion characteristics, which means that they can better control the refraction behavior of light of different wavelengths as it passes through the lens, significantly reducing the occurrence of axial chromatic aberration and improving image clarity and color accuracy. The technical solution of this application includes at least one lens with an Abbe number Vd ≥ 60 in the first lens group G1. Through reasonable arrangement, this ensures excellent color performance of the lens.

[0064] The refractive index Nd1 of first lens element L01 in first lens group G1 is set to ≥ 1.8. This high refractive index lens has better light focusing ability and can improve spherical aberration to a certain extent. Furthermore, first lens element L01 is paired with an aspherical lens in second lens group G2. Because aspherical lenses are made by precisely cutting a portion of a spherical surface, their complex surface can effectively compensate for or eliminate spherical aberration and other forms of aberration. By adjusting the aspherical coefficient, aberration can be minimized, thereby achieving better image quality.

[0065] In summary, the technical solution of the present application, based on the high refractive index setting of the first lens L01 in the first lens group G1 and the aspherical lens setting in the second lens group G2, can effectively correct the spherical aberration that often occurs in the focusing lens. By rationally arranging at least one lens with a high Abbe number, the axial chromatic aberration that occurs in the lens can be effectively corrected, thereby achieving good aberration correction and improving the imaging quality of the lens.

[0066] The large aperture, focus-locking, telephoto photography lens provided in this application is an ideal choice for professional photographers and advanced photography enthusiasts, capable of providing excellent image quality in various lighting conditions.

[0067] In some embodiments, the first lens group G1 includes a first cemented lens group consisting of a positive power lens and a negative power lens, and the number of the first cemented lens group is at least one.

[0068] The combination of a positive and negative power lens can produce a specific focal length and light-converging effect. Positive power lenses converge light, while negative power lenses diverge it. By precisely adjusting their combination and relative positions, light can be precisely controlled to achieve the desired imaging effect. In this embodiment, when the first cemented lens group is composed of a positive and negative power lens, lenses with different focal lengths and optical properties are combined. This design helps correct or balance various aberrations, such as spherical aberration, chromatic aberration, and field curvature, further optimizing the optical performance of the lens.

[0069] When there are multiple groups of first cemented lens groups, higher design flexibility can be provided to further optimize imaging quality and control aberrations. Each cemented lens group can be corrected for specific aberrations, thereby achieving more uniform imaging performance throughout the focal length range of the lens.

[0070] In some embodiments, the first lens group G1 includes, from the object side to the image side, a first lens L01 with positive refractive power, a second lens L02 with positive refractive power, a third lens L03 with positive refractive power, a fourth lens L04 with positive refractive power, a fifth lens L05 with negative refractive power, and a sixth lens L06 with negative refractive power; wherein the Abbe number Vd of the second lens L02, the third lens L03, and the fourth lens L04 are ≥ 60; and the fourth lens L04 and the fifth lens L05 are combined into a first cemented lens group.

[0071] This embodiment proposes a specific configuration for the first lens group G1. The Abbe numbers Vd ≥ 60 for the second lens element L02, the third lens element L03, and the fourth lens element L04 ensure high performance in dispersion correction. When these lenses are combined with the negative-power fifth lens element L05 and the sixth lens element L06, the entire first lens group G1 effectively corrects dispersion while maintaining sufficient light convergence, improving image color reproduction.

[0072] The fourth lens L04 and the fifth lens L05 are combined into a first cemented lens group to correct various aberrations, such as spherical aberration, chromatic aberration, and field curvature, thereby improving image clarity and overall quality. The fifth lens L05 and the sixth lens L06 have negative power, which can diverge light and help balance the excessive convergence effect of the positive lens in front, avoiding excessive spherical aberration and dispersion.

[0073] In some embodiments, the fourth lens L04 and the fifth lens L05 satisfy the following Conditional Formula:

[0074] |Vd4-Vd5|≥30, (4);

[0075] Wherein, Vd4 is the Abbe number of the fourth lens element L04 in the first lens group G1 with respect to the light with a wavelength of 587.6 nm; Vd5 is the Abbe number of the fifth lens element L05 in the first lens group G1 with respect to the light with a wavelength of 587.6 nm.

[0076] In this embodiment, the difference in Abbe numbers between the fourth lens L04 and the fifth lens L05 is required to be at least 30. This ensures that the fourth lens L04 and the fifth lens L05 effectively complement each other in terms of dispersion correction. When their Abbe numbers differ significantly, one lens may have stronger correction capabilities for one color of light, while the other lens may have stronger correction capabilities for another color of light. By combining these two lenses to form a first cemented lens group, effective correction for multiple colors of light can be achieved, thereby improving the color reproduction of the entire lens.

[0077] In some embodiments, the second lens group G2 includes, from the object side to the image side, a second cemented lens group with negative optical power and an aspheric lens; the surface of the lens close to the aperture stop STP in the second cemented lens group is bent toward the aperture stop STP.

[0078] In this embodiment, the second cemented lens group has negative optical power, which can further balance the excessive convergence effect brought by the first lens L01, avoid excessive spherical aberration and dispersion, and thus maintain imaging clarity and chromatic aberration accuracy.

[0079] The surface of the lens closest to the aperture stop STP in the second cemented lens group is curved toward the aperture stop STP. This design helps reduce the angle of incidence of light, resulting in more even distribution of light as it passes through the second cemented lens group, reducing aberrations and distortion. It also helps increase the light throughput of the lens, enabling better imaging even in low-light environments.

[0080] Furthermore, aspherical lenses are used to precisely control the propagation path of light and correct various aberrations, such as spherical aberration.

[0081] In some embodiments, the second lens group G2 includes, from the object side to the image side, a seventh lens L07 with negative refractive power, an eighth lens L08 with positive refractive power, and a ninth lens L09 with positive refractive power. The seventh lens L07 and the eighth lens L08 are combined to form a second cemented lens group. The refractive index Nd8 of the eighth lens L08 is ≥ 1.8. The ninth lens L09 is an aspherical lens.

[0082] In this embodiment, a specific configuration of the second lens group G2 is proposed. The seventh lens L07 and the eighth lens L08 are combined into a second cemented lens group, which work together to achieve precise control of light. The ninth lens L09 is an aspherical lens to correct spherical aberration.

[0083] In particular, the refractive index Nd8 of the eighth lens element L08 is ≥ 1.8, indicating that the eighth lens element L08 is made of a high-refractive-index material. This high-refractive-index material helps reduce the number and size of lens elements, thereby reducing the weight and miniaturization of the second lens group G2 and facilitating adjustment. It also increases the light transmittance of the lens, improving image brightness and clarity.

[0084] In some embodiments, the seventh lens L07 and the eighth lens L08 satisfy the following conditional formula:

[0085] |Nd7-Nd8|≥0.2, (5);

[0086] Wherein, Nd7 is the refractive index of the seventh lens L07 in the second lens group G2 with respect to the light with a wavelength of 587.6 nm; Nd8 is the refractive index of the eighth lens L08 in the second lens group G2 with respect to the light with a wavelength of 587.6 nm.

[0087] In this embodiment, the difference in refractive index between the seventh lens element L07 and the eighth lens element L08 is required to be at least 0.2. This ensures that the seventh lens element L07 and the eighth lens element L08 effectively complement each other in optical performance. A large difference in refractive index allows for more flexible control of light propagation paths and focusing, thereby correcting aberrations and improving image quality.

[0088] In some embodiments, the third lens group G3 includes, from the object side to the image side, a tenth lens L10 with positive refractive power, an eleventh lens L11 with negative refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with positive refractive power, a fourteenth lens L14 with negative refractive power, and a fifteenth lens L15 with negative refractive power; wherein the tenth lens L10 and the eleventh lens L11 are combined to form a third cemented lens group with negative refractive power, and the thirteenth lens L13 and the fourteenth lens L14 are combined to form a fourth cemented lens group with negative refractive power.

[0089] This embodiment proposes a specific configuration for the third lens group G3. From the object side to the image side, the third lens group G3 comprises multiple lenses with varying optical powers, some of which form a third cemented lens group and a fourth cemented lens group. By rationally combining lenses with varying optical powers and cemented lens groups, high-quality imaging and optical performance are achieved, demonstrating precise control and optimization of optical performance.

[0090] In some embodiments, the third lens group G3 includes, from the object side to the image side, a tenth lens L10 with positive refractive power, an eleventh lens L11 with negative refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with negative refractive power, a fourteenth lens L14 with positive refractive power, and a fifteenth lens L15 with negative refractive power; wherein the tenth lens L10 and the eleventh lens L11 are combined to form a third cemented lens group with negative refractive power, and the thirteenth lens L13 and the fourteenth lens L14 are combined to form a fourth cemented lens group with negative refractive power.

[0091] This embodiment proposes another specific arrangement for the third lens group G3. The tenth lens L10 through the fifteenth lens L15 are arranged in alternating patterns of positive-negative-positive-negative-positive-negative power. This helps balance light convergence and divergence, reduces aberrations, and improves image quality. Furthermore, by combining the tenth lens L10 and the eleventh lens L11 into a third cemented lens group, and the thirteenth lens L13 and the fourteenth lens L14 into a fourth cemented lens group, these cemented lens groups correct aberrations while maintaining sufficient light control capabilities, thereby improving image quality.

[0092] In some embodiments, the third lens group G3 includes, from the object side to the image side, a tenth lens L10 with negative refractive power, an eleventh lens L11 with positive refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with negative refractive power, a fourteenth lens L14 with positive refractive power, and a fifteenth lens L15 with negative refractive power; wherein the tenth lens L10 and the twelfth lens L12 are combined to form a third cemented lens with positive refractive power, and the twelfth lens L12 and the thirteenth lens L13 are combined to form a fourth cemented lens group with negative refractive power.

[0093] This embodiment proposes another specific configuration for the third lens group G3. From the object side to the image side, the third lens group G3 comprises, in sequence, multiple lenses with varying optical powers, some of which form cemented lens groups. Similarly, by properly combining lenses with varying optical powers and cemented lens groups, light is precisely controlled, achieving high-quality imaging and optical performance.

[0094] In this application, a parallel glass plate GL, configured as a filter, is positioned between the fifteenth lens L15 of the third lens group G3 and the image plane IMG. The parallel glass plate GL filters light to improve image quality. Specifically, it absorbs or reflects light of certain wavelengths to eliminate or minimize interfering factors such as chromatic aberration and stray light, thereby enhancing image contrast and clarity.

[0095] Example 1

[0096] Figure 1 The diagram shows the structure of a large aperture inner focus telephoto lens according to Example 1. Figure 1As shown, in this embodiment, the first lens group G1 includes, from the object side to the image side, a first lens L01 with positive refractive power, a second lens L02 with positive refractive power, a third lens L03 with positive refractive power, a fourth lens L04 with positive refractive power, a fifth lens L05 with negative refractive power, and a sixth lens L06 with negative refractive power, wherein the fourth lens L04 and the fifth lens L05 are combined to form a first cemented lens group with positive refractive power; the refractive index nd1 of the first lens L01 is ≥1.8; the Abbe number vd of the second lens L02, the third lens L03, and the fourth lens L04 is ≥60; the second lens group G2 includes, from the object side, a seventh lens L07 with negative refractive power, an eighth lens L08 with positive refractive power, and a sixth lens L09 with positive refractive power. The ninth lens L09; wherein the refractive index Vd8 of the eighth lens L08 is ≥1.8, the seventh lens L07 and the eighth lens L08 are combined to form a second cemented lens group with negative refractive power, and the ninth lens L09 is an aspherical lens; the third lens group G3 comprises, from the object side, a tenth lens L10 with positive refractive power, an eleventh lens L11 with negative refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with negative refractive power, a fourteenth lens L14 with positive refractive power, and a fifteenth lens L15 with negative refractive power, wherein the tenth lens L10 and the eleventh lens L11 are combined to form a third cemented lens group with negative refractive power, and the thirteenth lens L13 and the fourteenth lens L14 are combined to form a fourth cemented lens group with negative refractive power.

[0097] In this embodiment, the numerical data of the large aperture inner focus telephoto lens are shown in Tables 1 to 4:

[0098] Table 1

[0099]

[0100]

[0101] Table 2

[0102]

[0103]

[0104] Table 3

[0105]

[0106] Table 4

[0107]

[0108] The surface number indicates the surface number of each lens from the object side to the image side.

[0109] Figure 2 and Figure 3 The spherical aberration, field curvature, and distortion curves of Example 1 when in focus at infinity are shown. Figure 4 and Figure 5 Graphs showing spherical aberration, field curvature, and distortion of Example 1 at the minimum focusing distance.

[0110] The spherical aberration curve graph shows the spherical aberration curve at an aperture number of 1.47. The F-line, D-line, and C-line represent spherical aberration at wavelengths of 486 nm, 587 nm, and 656 nm, respectively. The abscissa represents the spherical aberration value, and the ordinate represents the field of view. The field curvature curve graph shows the field curvature curve at a half-field angle ω of 14.02°. The dashed line S represents the value of the chief ray D on the sagittal image plane, and the solid line T represents the value of the chief ray D on the meridional image plane. The abscissa represents the field curvature value, and the ordinate represents the field of view. The distortion curve graph shows the distortion curve at a half-field angle ω of 14.02°. The abscissa represents the distortion value, and the ordinate represents the field of view. The above descriptions regarding the various spherical aberrations, field curvature, and distortion curve graphs are the same as those for the other embodiments and will not be repeated here. As can be seen from Figures 2-5, the photographic lens of Example 1 exhibits excellent imaging performance.

[0111] Example 2

[0112] Figure 6 The diagram shows the structure of a large aperture inner focus telephoto lens according to Example 2. Figure 6As shown, in this embodiment, the first lens group G1 includes, from the object side to the image side, a first lens L01 with positive refractive power, a second lens L02 with positive refractive power, a third lens L03 with positive refractive power, a fourth lens L04 with positive refractive power, a fifth lens L05 with negative refractive power, and a sixth lens L06 with negative refractive power, wherein the fourth lens L04 and the fifth lens L05 are combined to form a first cemented lens group with positive refractive power; the refractive index nd1 of the first lens L01 is ≥1.8; the Abbe number vd of the second lens L02, the third lens L03, and the fourth lens L04 is ≥60; the second lens group G2 includes, from the object side, a seventh lens L07 with negative refractive power, an eighth lens L08 with positive refractive power, and a sixth lens L09 with positive refractive power. The ninth lens L09; wherein the refractive index Vd8 of the eighth lens L08 is ≥1.8, the seventh lens L07 and the eighth lens L08 are combined to form a second cemented lens group with negative refractive power, and the ninth lens L09 is an aspherical lens; the third lens group G3 comprises, from the object side, a tenth lens L10 with positive refractive power, an eleventh lens L11 with negative refractive power, a twelfth lens L12 with positive refractive power, a thirteenth lens L13 with negative refractive power, a fourteenth lens L14 with positive refractive power, and a fifteenth lens L15 with negative refractive power, wherein the tenth lens L10 and the eleventh lens L11 are combined to form a third cemented lens group with negative refractive power, and the thirteenth lens L13 and the fourteenth lens L14 are combined to form a fourth cemented lens group with negative refractive power.

[0113] In this embodiment, the numerical data of the large aperture inner focus telephoto lens are shown in Tables 5 to 8:

[0114] Table 5

[0115]

[0116]

[0117]

[0118] Table 6

[0119]

[0120] Table 7

[0121]

[0122] Table 8

[0123]

[0124]

[0125] Figure 7 and Figure 8 The spherical aberration, field curvature, and distortion curves of Example 2 when focused at infinity are shown. Figure 9 and Figure 10 Graphs showing spherical aberration, field curvature, and distortion for Example 2 at the closest focusing distance.

[0126] As can be seen from Figures 7-10, the camera lens of this embodiment 2 has good imaging effect.

[0127] Example 3

[0128] Figure 11 The diagram shows the structure of a large aperture inner focus telephoto lens according to Example 3. Figure 11 As shown, in this embodiment, the first lens group G1 includes, from the object side to the image side, a first lens L01 with positive refractive power, a second lens L02 with positive refractive power, a third lens L03 with positive refractive power, a fourth lens L04 with positive refractive power, a fifth lens L05 with negative refractive power, and a sixth lens L06 with negative refractive power, wherein the fourth lens L04 and the fifth lens L05 are combined to form a first cemented lens group with positive refractive power; the refractive index nd1 of the first lens L01 is ≥1.8; the Abbe number vd of the second lens L02, the third lens L03, and the fourth lens L04 is ≥60; the second lens group G2 includes, from the object side, a seventh lens L07 with negative refractive power, an eighth lens L08 with positive refractive power, and a sixth lens L09 with positive refractive power. The ninth lens group G3 comprises, from the object side, a tenth lens L10 with negative power, an eleventh lens L11 with positive power, a twelfth lens L12 with positive power, a thirteenth lens L13 with negative power, a fourteenth lens L14 with positive power, and a fifteenth lens L15 with negative power. The tenth lens L10 and the eleventh lens L11 are combined to form a third cemented lens group with negative power, and the thirteenth lens L13 and the fourteenth lens L14 are combined to form a fourth cemented lens group with negative power.

[0129] In this embodiment, the numerical data of the large aperture inner focus telephoto lens are shown in Tables 9 to 12:

[0130] Table 9

[0131]

[0132]

[0133] Table 10

[0134]

[0135] Table 11

[0136]

[0137]

[0138] Table 12

[0139]

[0140] Figure 12 and Figure 13 The spherical aberration, field curvature, and distortion curves of Example 3 when in focus at infinity are shown. Figure 14 and Figure 15 Graphs showing spherical aberration, field curvature, and distortion for Example 3 at the closest focusing distance.

[0141] As can be seen from Figures 12-15 , the camera lens of this embodiment 3 has good imaging effect.

[0142] The present application also provides a photographic device. The photographic device includes an image sensor and a large aperture, inner-focus, telephoto photographic lens as described above, wherein the image sensor and the large aperture, inner-focus, telephoto photographic lens are detachably connected. The image sensor is a camera.

[0143] In this embodiment, the photographic device includes and adopts all the technical solutions of all the embodiments of the above-mentioned large aperture inner-focus telephoto photographic lens, and therefore has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0144] The above description is only a partial or preferred embodiment of the present application. Neither the text nor the drawings can limit the scope of protection of the present application. Any equivalent structural transformation made by using the contents of the present application specification and drawings under the overall concept of the present application, or direct / indirect application in other related technical fields, is included in the scope of protection of the present application.

Claims

1. A large aperture inner focus telephoto lens, characterized in that: The lens system comprises, from the object side to the image side, a first lens group with positive optical power, an aperture stop, a second lens group with positive optical power, and a third lens group with negative optical power; during focusing, the second lens group moves along the optical axis, while the positions of the first lens group and the third lens group relative to the image plane remain unchanged; The first lens group, the second lens group, and the third lens group satisfy the following conditional formula: 1≤F1 / F≤3, (1); 0.5≤F2 / F≤2, (2); -6≤F3 / F≤-3, (3); Among them, F1 represents the composite focal length of the first lens group, F2 represents the composite focal length of the second lens group, F3 represents the composite focal length of the third lens group, and F represents the focal length of the photographic lens.

2. The large aperture inner-focus telephoto lens according to claim 1, wherein: The first lens group includes, from the object side to the image side, a first lens with positive refractive power and at least one lens with positive refractive power and an Abbe number Vd≥60; the refractive index Nd1 of the first lens is ≥1.

8.

3. The large aperture inner focusing telephoto lens according to claim 2, wherein: The first lens group includes a first cemented lens group consisting of a positive power lens and a negative power lens, and the number of the first cemented lens group is at least one.

4. The large aperture inner focusing telephoto lens according to claim 3, wherein: The first lens group includes, from the object side to the image side, a first lens having positive refractive power, a second lens having positive refractive power, a third lens having positive refractive power, a fourth lens having positive refractive power, a fifth lens having negative refractive power, and a sixth lens having negative refractive power; The Abbe numbers Vd of the second lens, the third lens, and the fourth lens are ≥60; the fourth lens and the fifth lens are combined to form the first cemented lens group.

5. The large aperture inner focusing telephoto lens according to claim 4, characterized in that: The fourth lens and the fifth lens satisfy the following conditional formula: |Vd4-Vd5|≥30, (4); Wherein, Vd4 is the Abbe number of the fourth lens in the first lens group with respect to the light with a wavelength of 587.6 nm; Vd5 is the Abbe number of the fifth lens in the first lens group with respect to the light with a wavelength of 587.6 nm.

6. The large aperture inner focusing telephoto lens according to claim 1, wherein: The second lens group includes, from the object side to the image side, a second cemented lens group with negative optical power and an aspheric lens with positive optical power; the surface of the lens close to the aperture stop in the second cemented lens group is bent toward the aperture stop.

7. The large aperture inner focusing telephoto lens according to claim 6, wherein: The second lens group includes, from the object side to the image side, a seventh lens having negative refractive power, an eighth lens having positive refractive power, and a ninth lens having positive refractive power; The seventh lens and the eighth lens are combined to form the second cemented lens group; the refractive index Nd8 of the eighth lens is ≥1.8; and the ninth lens is an aspherical lens.

8. The large aperture inner focusing telephoto lens according to claim 7, wherein: The seventh lens and the eighth lens satisfy the following conditional formula: |Nd7-Nd8|≥0.2, (5); Wherein, Nd7 is the refractive index of the seventh lens element in the second lens group with respect to the light with a wavelength of 587.6 nm; Nd8 is the refractive index of the eighth lens element in the second lens group with respect to the light with a wavelength of 587.6 nm.

9. The large aperture inner-focus telephoto lens according to any one of claims 1 to 8, wherein: The third lens group includes, from the object side to the image side, a tenth lens having positive refractive power, an eleventh lens having negative refractive power, a twelfth lens having positive refractive power, a thirteenth lens having positive refractive power, a fourteenth lens having negative refractive power, and a fifteenth lens having negative refractive power; The tenth lens and the eleventh lens are combined to form a third cemented lens group with negative optical power, and the thirteenth lens and the fourteenth lens are combined to form a fourth cemented lens group with negative optical power.

10. The large aperture inner-focus telephoto lens according to any one of claims 1 to 8, characterized in that: The third lens group includes, from the object side to the image side, a tenth lens having positive refractive power, an eleventh lens having negative refractive power, a twelfth lens having positive refractive power, a thirteenth lens having negative refractive power, a fourteenth lens having positive refractive power, and a fifteenth lens having negative refractive power; The tenth lens and the eleventh lens are combined to form a third cemented lens group with negative optical power, and the thirteenth lens and the fourteenth lens are combined to form a fourth cemented lens group with negative optical power.

11. The large aperture inner-focus telephoto lens according to any one of claims 1 to 8, wherein: The third lens group includes, from the object side to the image side, a tenth lens having negative refractive power, an eleventh lens having positive refractive power, a twelfth lens having positive refractive power, a thirteenth lens having negative refractive power, a fourteenth lens having positive refractive power, and a fifteenth lens having negative refractive power. The tenth lens and the twelfth lens are combined into a third cemented lens with positive power, and the twelfth lens and the thirteenth lens are combined into a fourth cemented lens group with negative power.

12. A photographic device, characterized in that: The invention comprises an image sensor and a large aperture inner focus telephoto photographic lens as claimed in any one of claims 1 to 11, wherein the image sensor is detachably connected to the large aperture inner focus telephoto photographic lens.

Images