Full-frame large-aperture medium-focus lens

Abstract

The utility model discloses a full-frame large-aperture medium-focus lens, which comprises a first lens group, a second lens group, a third lens group and a fourth lens group which are sequentially arranged from an object side to an image side along an optical axis, the focal lengths of all the lens groups meet the following conditional expressions:-4lt; f (G1) / Flt; -1.5,-1.5; -2lt;-2lt; f (G3) / Flt; 1; 1lt; 1lt; f (G2) / f (G4) lt; 1; -2.5 lt,-2.5 lt; f (G4) / f (G1-G3) lt; and 1.5. The focusing assembly of the full-frame large-aperture medium-focus lens is only composed of one lens, so that the weight of a focusing group and the load of a pushing motor are reduced, and rapid focusing of the large-aperture medium-focus lens and imaging equipment is facilitated; moreover, the large-aperture medium-focus lens corrects various aberrations of various wavebands, enables the central field of view and the edge field of view to have enough resolution, has the advantages of simple structure, small size and large aperture, and can realize high resolution of imaging from infinity to close distance.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical lens technical field, concretely relates to a full frame large aperture mid focus lens. BACKGROUND

[0002] In recent years, although the multifunction of mobile phone replaces the daily photograph of card camera, but in the view of photography lover who has higher photographing requirement, micro single camera can experience perfect photography fun. Micro single camera has the advantages of small size, light weight, convenient carrying, larger image surface and aperture, and can experience better background blurring effect.

[0003] The existing large aperture mid focus lens has the problems of various aberrations and low resolution for some wave bands, and the focusing assembly inside the existing large aperture mid focus lens is heavy, and the load of the motor for pushing the focusing assembly to move to realize fast automatic focusing is large, which is not conducive to the fast focusing of the large aperture mid focus lens. UTILITY MODEL CONTENT

[0004] The utility model discloses in view of the existing technology's lack and market demand, provide a kind of full frame large aperture mid focus lens, it is small in size and light in weight, inside focusing component can be made to only by a lens, with the characteristics of fast focusing speed, excellent imaging performance, it is applicable to full frame optical imaging system.

[0005] To solve the above technical problems, the technical scheme of the utility model is as follows:

[0006] A kind of full frame large aperture mid focus lens, including first lens group, second lens group, third lens group, fourth lens group being sequentially arranged along optical axis from object side to image side;The focal length of all lens groups satisfies the following conditional formula:

[0007] -4<f (G1) / F<-1.5;

[0008] -2<f (G3) / F<1;

[0009] -1<f (G2) / f (G4)<1;

[0010] -2.5<f (G4) / f (G1-G3)<1.5;

[0011] Wherein, f (G1) represents the combined focal length of first lens group, f (G2) represents the combined focal length of second lens group, f (G3) represents the focal length of third lens group, f (G4) represents the combined focal length of fourth lens group, f (G1-G3) represents the combined focal length of first lens group, second lens group and third lens group, F represents the combined focal length of all lens groups;

[0012] The first lens group and the second lens group are provided with a diaphragm, and the third lens group only includes one lens; the first lens group, the second lens group and the fourth lens group keep different positions in the direction of the optical axis, and the third lens group moves along the direction of the optical axis to realize focusing.

[0013] Further, the first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence from the object side to the image side along the optical axis;

[0014] The first lens is a meniscus lens with the convex surface facing the object side;

[0015] The second lens is a biconvex lens;

[0016] The third lens is a biconcave lens;

[0017] The fourth lens is a meniscus lens with the convex surface facing the object side;

[0018] The fifth lens is a biconcave lens;

[0019] The sixth lens is a biconvex lens.

[0020] Further, the second lens group includes a seventh lens, an eighth lens and a ninth lens arranged in sequence from the object side to the image side along the optical axis;

[0021] The seventh lens is a biconvex lens;

[0022] The eighth lens is a meniscus lens with the convex surface facing the image side;

[0023] The ninth lens is a biconvex lens.

[0024] Further, the third lens group includes a tenth lens, and the tenth lens is a meniscus lens with the convex surface facing the object side.

[0025] Further, the fourth lens group includes an eleventh biconvex lens, a twelfth biconvex lens, a thirteenth biconcave lens and a fourteenth meniscus lens arranged in sequence from the object side to the image side along the optical axis;

[0026] The eleventh lens is a biconvex lens;

[0027] The twelfth lens is a biconvex lens;

[0028] The thirteenth lens is a biconcave lens

[0029] The fourteenth lens is a meniscus lens with the convex surface facing the image side.

[0030] Further, the distance between the tenth lens and the first lens satisfies the following conditional expression:

[0031] 0.4 < S3 / S < 0.6;

[0032] Wherein, S3 is the distance from the intersection of the optical axis of the tenth lens L10 object side to the image plane when infinity is focused, and S is the distance from the intersection of the first lens L1 object side and the optical axis to the image plane when infinity is focused.

[0033] Further, the first lens, the second lens, the twelfth lens and the fourteenth lens are all optical lenses with a refractive index higher than 1.9.

[0034] Further, the aperture of the full-frame large aperture macro lens is 1.3-2.

[0035] Further, the focal length range of the full-frame large aperture macro lens is 30mm-60mm.

[0036] Further, the fourth lens, the tenth lens and the eleventh lens are all aspherical lenses.

[0037] The full-frame large aperture macro lens has the following advantages: the full-frame large aperture macro lens corrects various aberrations of various wave bands, so that the central and edge fields have sufficient resolution, has the advantages of simple structure, small size and large aperture, and can realize high resolution of imaging from infinite distance to close distance. Through reasonable distribution of optical power, the full-frame large aperture macro lens has a 1.4 times large aperture while ensuring the brightness of the captured image. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical scheme in the specific embodiment of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiment or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0039] Figure 1 It is a cross-sectional structure schematic view of the full-frame large aperture macro lens in example 1 of the embodiment of the present application.

[0040] Figure 2 It is a spherical aberration graph of the full-frame large aperture macro lens in example 1 of the embodiment of the present application when the object distance is infinite.

[0041] Figure 3 It is a field curvature distortion graph of the full-frame large aperture macro lens in example 1 of the embodiment of the present application when the object distance is infinite.

[0042] Figure 4 It is a cross-sectional structure schematic view of the full-frame large aperture macro lens in example 2 of the embodiment of the present application.

[0043] Figure 5 This is a spherical aberration diagram of a full-frame, large-aperture, medium-focus lens in Example 2 of the embodiment of the present utility model when the object distance is infinite;

[0044] Figure 6 This is a field curvature distortion diagram of a full-frame, large-aperture, medium-focus lens at infinite object distance in Example 2 of an embodiment of the present invention.

[0045] Explanation of Reference Signs: G1, first lens group; G2, second lens group; G3, third lens group; G4, fourth lens group; L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; L7, seventh lens; L8, eighth lens; L9, ninth lens; L10, tenth lens; L11, eleventh lens; L12, twelfth lens; L13, thirteenth lens; L14, fourteenth lens. DETAILED DESCRIPTION

[0046] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0047] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] like Figures 1-6 A full-frame, large-aperture, medium-focus lens is shown, comprising a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4, arranged in sequence from the object side to the image side along the optical axis; the focal lengths of all lens groups satisfy the following conditional formula:

[0049] -4 <f(G1) / F<-1.5;

[0050] -2 <f(G3) / F<1;

[0051] -1 <f(G2) / f(G4)<1;

[0052] -2.5 < f(G4) / f(G1-G3) < 1.5;

[0053] wherein f(G1) represents the focal length of the first lens group G1, f(G2) represents the focal length of the second lens group G2, f(G3) represents the focal length of the third lens group, f(G4) represents the focal length of the fourth lens group, f(G1-G3) represents the combined focal length of the first lens group G1, the second lens group G2 and the third lens group G3, and F represents the combined focal length of all the lens groups.

[0054] In the present embodiment, the first lens group G1 includes, in order from the object side to the image side along the optical axis, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6.

[0055] The first lens L1 is a meniscus lens with the convex surface facing the object side, the second lens L2 is a double convex lens, the third lens L3 is a double concave lens, the fourth lens L4 is a meniscus lens with the convex surface facing the object side, the fifth lens L5 is a double concave lens, and the sixth lens L6 is a double convex lens. The second lens group G2 includes, in order from the object side to the image side along the optical axis, a seventh lens L7, an eighth lens L8, and a ninth lens L9. The seventh lens L7 is a double convex lens, the eighth lens L8 is a meniscus lens with the convex surface facing the image side, and the ninth lens L9 is a double convex lens. The third lens group G3 includes a tenth lens L10, which is a meniscus lens with the convex surface facing the object side. The fourth lens group G4 includes, in order from the object side to the image side along the optical axis, an eleventh lens L11, a twelfth lens L12, a thirteenth lens L3, and a fourteenth lens L14. The eleventh lens L11 is a double convex lens, the twelfth lens L12 is a double convex lens, the thirteenth lens L3 is a double concave lens, and the fourteenth lens L14 is a meniscus lens with the convex surface facing the image side.

[0056] Further, a diaphragm is provided between the first lens group G1 and the second lens group G2. During focusing, the first lens group G1, the second lens group G2, and the fourth lens group G4 remain at different positions in the direction of the optical axis, and the third lens group G3 moves in the direction of the optical axis to achieve focusing.

[0057] Further, the distance between the tenth lens L10 and the first lens L1 satisfies the following conditional expression:

[0058] 0.4 < S3 / S < 0.6;

[0059] wherein S3 is the distance from the intersection of the optical axis (L10 left vertex) on the object side surface of the tenth lens L10 to the image plane during infinity focus, and S is the distance from the intersection of the optical axis (L1 left vertex) on the object side surface of the first lens L1 to the image plane during infinity focus.

[0060] As a preferred solution, the first lens L1, the second lens L2, the twelfth lens L12 and the fourteenth lens L14 are all optical lenses with a refractive index higher than 1.9.

[0061] As a preferred solution, the aperture of the full-frame large-aperture medium-telephoto lens is 1.3-2. The focal length range of the full-frame large-aperture medium-telephoto lens is 30mm-60mm.

[0062] As a preferred solution, the fourth lens L4, the tenth lens L10 and the eleventh lens L11 are all aspherical lenses.

[0063] In the example 1 of the utility model, the related parameters of each lens are shown in the following table 1-1, table 1-2 and table 1-3:

[0064]

[0065]

[0066] Table 1-1

[0067]

[0068] Table 1-2

[0069]

[0070] Table 1-3

[0071] In the example 2 of the utility model, the related parameters of each lens are shown in the following table 2-1, table 2-2 and table 2-3:

[0072]

[0073]

[0074] Table 2-1

[0075]

[0076] Table 2-2

[0077]

[0078]

[0079] Table 2-3

[0080] The data of the example 1 and the example 2 of the utility model are shown in the following table 3:

[0081] Conditional expression Example 1 Example 2 f(G1) / F -2.466622339 -1.970954196 f(G3) / F 0.961793347 0.89627193 f(G2) / f(G4) -0.548308795 -0.43708391 f(G4) / f(G-G3) -2.053940502 -2.412884392 S3 / S 0.49178904 0.474313975

[0082] Table 3

[0083] As Figure 1 shown in the embodiment of the utility model, eighth lens L8 can move focus between seventh lens L7 and ninth lens L9 along the optical axis, because eighth lens L8 focuses in, therefore can keep the overall length of the lens unchanged when the lens adjusts focal length.

[0084] This full-frame aperture mid-focus lens corrects various aberrations of each waveband, so that the center and edge field have sufficient resolution, has the advantages of simple structure, small size, large aperture, and can realize high resolution of imaging from infinity to close distance.

[0085] It should be pointed out that the large aperture mid-focus lens adopts integrated design, realizes miniaturization of the lens, and obtains excellent super cost-effective optical performance such as high resolution, low breathing and low distortion, and can be designed to match the bayonet of various brands of cameras on the market according to actual use requirements, so as to realize personalized customization and cooperation with the general.

[0086] Obviously, the above embodiments are only examples for clearly illustrating, and not limit the embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the utility model.

Claims

1. A full-frame, large-aperture, medium-focus lens, characterized in that: The invention comprises a first lens group (G1), a second lens group (G2), a third lens group (G3), and a fourth lens group (G4) arranged in sequence from the object side to the image side along the optical axis; the focal lengths of all lens groups satisfy the following conditional formula: -4 <f(G1) / F<-1.5; -2 <f(G3) / F<1; -1 <f(G2) / f(G4)<1; -2.5 <f(G4) / f(G1-G3)<1.5; Wherein, f(G1) represents the focal length of the first lens group (G1), f(G2) represents the focal length of the second lens group (G2), f(G3) represents the focal length of the third lens group (G3), f(G4) represents the focal length of the fourth lens group (G4), f(G1-G3) represents the combined focal length of the first lens group (G1), the second lens group (G2), and the third lens group (G3), and F represents the combined focal length of all lens groups; The third lens group (G3) includes only one lens; the third lens group (G3) moves along the direction of the optical axis to achieve focusing.

2. The full-frame large aperture medium focal length lens according to claim 1, characterized in that: The first lens group (G1) includes a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), and a sixth lens (L6) arranged in sequence from the object side to the image side along the optical axis; The first lens (L1) is a meniscus lens with a convex surface facing the object side; The second lens (L2) is a biconvex lens; The third lens (L3) is a biconcave lens; The fourth lens (L4) is a meniscus lens with a convex surface facing the object side; The fifth lens (L5) is a biconcave lens; The sixth lens (L6) is a biconvex lens.

3. The full-frame large aperture medium focal length lens according to claim 2, characterized in that: The second lens group (G2) includes a seventh lens (L7), an eighth lens (L8), and a ninth lens (L9) arranged in sequence from the object side to the image side along the optical axis; The seventh lens (L7) is a biconvex lens; The eighth lens (L8) is a meniscus lens with a convex surface facing the image side; The ninth lens (L9) is a biconvex lens.

4. The full-frame large aperture medium focal length lens according to claim 3, characterized in that: The third lens group (G3) includes a tenth lens (L10), and the tenth lens (L10) is a meniscus lens with a convex surface facing the object side.

5. The full-frame large aperture medium focal length lens according to claim 4, characterized in that: The fourth lens group (G4) includes an eleventh lens (L11), a twelfth lens (L12), a thirteenth lens (L13), and a fourteenth lens (L14) arranged in sequence from the object side to the image side along the optical axis; The eleventh lens (L11) is a biconvex lens; The twelfth lens (L12) is a biconvex lens; The thirteenth lens (L13) is a biconcave lens The fourteenth lens (L14) is a meniscus lens with a convex surface facing the image side.

6. The full-frame large aperture medium focal length lens according to claim 5, characterized in that: The distance between the tenth lens (L10) and the first lens (L1) satisfies the following conditional formula: 0.4 <S3 / S<0.6; Wherein, S3 is the distance from the intersection of the optical axis of the object side surface of the tenth lens (L10) to the image plane when the lens is focused at infinity, and S is the distance from the intersection of the object side surface of the first lens (L1) and the optical axis to the image plane when the lens is focused at infinity.

7. The full-frame large aperture medium focal length lens according to claim 5, characterized in that: The first lens (L1), the second lens (L2), the twelfth lens (L12) and the fourteenth lens (L14) are all optical lenses with a refractive index higher than 1.

9.

8. The full-frame large aperture medium focal length lens according to claim 1, wherein: The aperture of the full-frame large aperture mid-focus lens is 1.3-2.

9. The full-frame, large-aperture, medium-focus lens according to claim 1, wherein: The focal length range of the full-frame large aperture medium-focus lens is 30mm-60mm.

10. The full-frame large aperture medium focal length lens according to claim 5, characterized in that: The fourth lens (L4), the tenth lens (L10) and the eleventh lens (L11) are all aspherical lenses.

Images