Large-aperture half-frame lens

Abstract

The utility model discloses a large-aperture half-frame lens, which belongs to the technical field of optical lenses and 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: 1.2 < f (G1) / f (G2-G4) < 3.7; -3.8 < f (G3) / f (G2-G4) <-1.3; 1.6 < f (G1) / f < 4.8. According to the large-aperture half-frame lens, various aberrations of various wave bands are corrected, the central field of view and the edge field of view have enough resolution, the large-aperture half-frame lens has the advantages of being simple in structure, small in size and large in aperture, and the high resolution of imaging with the object distance from infinity to close distance can be achieved.

Description

A large aperture APS-C lens Technical Field

[0001] This utility model relates to the field of optical lens technology, specifically to a large aperture APS-C lens. Background Technology

[0002] In recent years, although the multi-functionality of mobile phones has replaced point-and-shoot cameras for everyday photography, for photography enthusiasts with higher demands, mirrorless cameras offer a more perfect photographic experience. Mirrorless cameras have advantages such as small size, light weight, portability, larger image sensor and aperture, and can deliver better background blur effects.

[0003] Existing large-aperture APS-C lenses suffer from various aberrations and low resolution in certain wavelength bands. Summary of the Invention

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the defects of existing large aperture APS-C lenses in imaging some bands, such as various aberrations, low resolution, and high cost, and thus provide a large aperture APS-C lens.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0006] A large-aperture APS-C lens includes a first lens group, a second lens group, a third lens group, and a fourth lens group arranged sequentially along the optical axis from the object side to the image side; the focal lengths of all lens groups satisfy the following condition:

[0007] 1.2<f(G1) / f(G2-G4)<3.7;

[0008] -3.8<f(G3) / f(G2-G4)<-1.3;

[0009] 1.6 < f(G1) / f < 4.8;

[0010] Where f(G1) represents the focal length of the first lens group, f(G2-G4) represents the combined focal length of the second to fourth lens groups, f(G3) represents the focal length of the third lens group, and f represents the combined focal length of all lens groups.

[0011] Furthermore, an aperture stop is provided between the first lens group and the second lens group, and the third lens group can move along the direction of the optical axis to achieve focusing.

[0012] Furthermore, the first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged sequentially along the optical axis from the object side to the image side;

[0013] The first lens is a biconvex positive power lens;

[0014] The second lens is a meniscus negative power lens with its convex surface facing the object side;

[0015] The third lens is a biconcave negative power lens;

[0016] The fourth lens is a biconvex positive power lens;

[0017] The fifth lens is a meniscus positive power lens with its convex surface facing the image side;

[0018] The sixth lens is a biconvex positive power lens;

[0019] The seventh lens is a meniscus positive power lens with its convex surface facing the object side;

[0020] The eighth lens is a meniscus negative power lens with its convex surface facing the object side.

[0021] Furthermore, the second lens group includes a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens arranged sequentially along the optical axis from the object side to the image side;

[0022] The ninth lens is a biconcave negative power lens;

[0023] The tenth lens is a biconvex positive power lens;

[0024] The eleventh lens is a meniscus positive power lens with its convex surface facing the image side.

[0025] The twelfth lens is a plano-convex positive power lens.

[0026] Furthermore, the third lens group includes a thirteenth lens; the thirteenth lens is a meniscus negative power lens with its convex surface facing the object side.

[0027] Furthermore, the fourth lens group includes a fourteenth lens, a fifteenth lens, and a sixteenth lens arranged sequentially along the optical axis from the object side to the image side;

[0028] The fourteenth lens is a biconvex positive power lens;

[0029] The fifteenth lens is a biconvex positive power lens;

[0030] The sixteenth lens is a biconcave negative power lens.

[0031] Furthermore, the adjacent surfaces of the third lens and the fourth lens are glued together; and / or, the adjacent surfaces of the seventh lens and the eighth lens are glued together; the adjacent surfaces of the ninth lens and the tenth lens are glued together; and / or, the adjacent surfaces of the fifteenth lens and the sixteenth lens are glued together.

[0032] Furthermore, the fifth, eleventh, and thirteenth lenses are all aspherical lenses, while the first, second, third, fourth, sixth, seventh, eighth, ninth, tenth, twelfth, fourteenth, fifteenth, and sixteenth lenses are all spherical lenses.

[0033] Furthermore, the aperture of the large-aperture APS-C lens is less than 1, the large-aperture APS-C lens is a fixed-focus lens, the focal length range of the large-aperture APS-C lens is 15mm-30mm, and the field of view 2ω of the large-aperture APS-C lens is 60°-68°.

[0034] Furthermore, the total optical length of the large-aperture APS-C lens does not exceed 130mm.

[0035] The present invention has the following advantages: the large aperture half-frame lens corrects various aberrations in each band, so that the center and edge fields of view have sufficient resolution. It has the advantages of simple structure, small size and large aperture, and can achieve high resolution imaging from infinity to close distance. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 is a schematic diagram of the cross-sectional structure of the large aperture half-frame lens in an embodiment of this utility model;

[0038] Figure 2 is a field curvature diagram of the large aperture half-frame lens in an embodiment of this utility model;

[0039] Figure 3 is a distortion diagram of the large aperture APS-C lens in an embodiment of this utility model.

[0040] Explanation of reference numerals in the attached diagram: G1, first lens group; G2, second lens group; G3, third lens group; G4, fourth lens group; 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, sixth lens; 7, seventh lens; 8, eighth lens; 9, ninth lens; 10, tenth lens; 11, eleventh lens; 12, twelfth lens; 13, thirteenth lens; 14, fourteenth lens; 15, fifteenth lens; 16, sixteenth lens. Detailed Implementation

[0041] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0042] 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 the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of 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.

[0043] Figure 1 shows a large-aperture APS-C lens, comprising a first lens group G1, a second lens group G2, a third lens group G3, and a fourth lens group G4 arranged sequentially along the optical axis from the object side to the image side; the focal lengths of all lens groups satisfy the following condition:

[0044] 1.2<f(G1) / f(G2-G4)<3.7;

[0045] -3.8<f(G3) / f(G2-G4)<-1.3;

[0046] 1.6 < f(G1) / f < 4.8;

[0047] Where f(G1) represents the focal length of the first lens group G1, f(G2-G4) represents the combined focal length of the second lens group G2 to the fourth lens group G4, f(G3) represents the focal length of the third lens group G3, and f represents the combined focal length of all lens groups.

[0048] In this embodiment, the first lens group G1 includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, and an eighth lens 8 arranged sequentially along the optical axis from the object side to the image side. Specifically, the first lens 1 is a biconvex positive diopter lens; the second lens 2 is a meniscus negative diopter lens with its convex surface facing the object side; the third lens 3 is a biconcave negative diopter lens; the fourth lens 4 is a biconvex positive diopter lens; the fifth lens 5 is a meniscus positive diopter lens with its convex surface facing the image side; the sixth lens 6 is a biconvex positive diopter lens; the seventh lens 7 is a meniscus positive diopter lens with its convex surface facing the object side; and the eighth lens 8 is a meniscus negative diopter lens with its convex surface facing the object side.

[0049] The second lens group G2 includes a ninth lens 9, a tenth lens 10, an eleventh lens 11, and a twelfth lens 12 arranged sequentially along the optical axis from the object side to the image side. Among them, the ninth lens 9 is a biconcave negative power lens; the tenth lens 10 is a biconvex positive power lens; the eleventh lens 11 is a meniscus positive power lens with its convex surface facing the image side; and the twelfth lens 12 is a plano-convex positive power lens.

[0050] The third lens group includes the thirteenth lens 13, which is a meniscus negative power lens with its convex surface facing the object side.

[0051] The fourth lens group G4 includes a fourteenth lens 14, a fifteenth lens 15, and a sixteenth lens 16 arranged sequentially along the optical axis from the object side to the image side. Among them, the fourteenth lens 14 is a biconvex positive power lens; the fifteenth lens 15 is a biconvex positive power lens; and the sixteenth lens 16 is a biconcave negative power lens.

[0052] In this embodiment, an aperture stop is provided between the first lens group G1 and the second lens group G2, and the third lens group G3 can move along the optical axis to achieve focusing. The third lens group G3 has only a single thirteenth lens 13 for focusing, making focusing more convenient and simple.

[0053] In this embodiment, the fifth lens 5, the eleventh lens 11, and the thirteenth lens 13 are all aspherical lenses, while the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, the tenth lens 10, the twelfth lens 12, the fourteenth lens 14, the fifteenth lens 15, and the sixteenth lens 16 are all spherical lenses. This type of lens can effectively correct aberrations such as spherical aberration and field curvature, and can reduce the overall weight of the lens.

[0054] In this embodiment, the adjacent surfaces of the third lens 3 and the fourth lens 4 are cemented together; the adjacent surfaces of the seventh lens 7 and the eighth lens 8 are cemented together; the adjacent surfaces of the ninth lens 9 and the tenth lens 10 are cemented together; and the adjacent surfaces of the fifteenth lens 15 and the sixteenth lens 16 are cemented together. This cemented lens combination effectively corrects chromatic aberration, resulting in more realistic colors in the captured image.

[0055] In this embodiment, the aperture of the large-aperture APS-C lens is less than f / 1. The large-aperture APS-C lens is a fixed-focus lens with a focal length in the range of 15mm-30mm, and its field of view 2ω is 60°-68°. The total optical length of the large-aperture APS-C lens does not exceed 130mm.

[0056] The relevant parameters of each lens are shown in Table 1 below:

[0057]

[0058] Table 1

[0059] As shown in Figure 1, in this embodiment of the invention, the thirteenth lens 13 can move along the optical axis between the twelfth lens 12 and the fourteenth lens 14 for focusing. Because the thirteenth lens 13 focuses, the overall length of the lens can remain unchanged when the lens adjusts its focal length.

[0060] As can be seen from Figures 2 and 3, the field curvature of the large-aperture APS-C lens in the meridional (corresponding to T in Figure 2) and sagittal (corresponding to S in Figure 2) directions of light is between -0.1mm and 0.1mm; the maximum distortion of the large-aperture APS-C lens is within ±3%.

[0061] This large-aperture APS-C lens corrects various aberrations across different wavelengths, ensuring sufficient resolution in both the center and edge fields of view. It boasts advantages such as simple structure, small size, and large aperture, and can achieve high-resolution imaging from infinity to close distances.

[0062] It should be noted that this large-aperture APS-C lens adopts an integrated design, achieving a miniaturized lens while obtaining excellent optical performance such as high resolution, low breathing, and low distortion at a very cost-effective price. It can be designed to match the lens mounts of various brands of cameras on the market according to actual usage needs, so as to achieve personalized customization and universal compatibility.

[0063] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A large-aperture APS-C lens, characterized in that, It includes 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 expressions: 1.2 < f(G1) / f(G2 - G4) < 3.7; -3.8 < f(G3) / f(G2 - G4) < -1.3; 1.6 < f(G1) / f < 4.8; where f(G1) represents the focal length of the first lens group (G1), f(G2 - G4) represents the combined focal length of the second lens group (G2) to the fourth lens group (G4), f(G3) represents the focal length of the third lens group (G3), and f represents the combined focal length of all lens groups; the first lens group (G1) includes a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7), and an eighth lens (8) arranged in sequence from the object side to the image side along the optical axis; the first lens (1) is a biconvex positive-power lens; the second lens (2) is a meniscus negative-power lens with the convex surface facing the object side; the third lens (3) is a biconcave negative-power lens; the fourth lens (4) is a biconvex positive-power lens; the fifth lens (5) is a meniscus positive-power lens with the convex surface facing the image side; the sixth lens (6) is a biconvex positive-power lens; the seventh lens (7) is a meniscus positive-power lens with the convex surface facing the object side; the eighth lens (8) is a meniscus negative-power lens with the convex surface facing the object side.

2. The large aperture APS-C lens according to claim 1, characterized in that, There is an aperture stop between the first lens group (G1) and the second lens group (G2), and the third lens group (G3) can move along the direction of the optical axis to achieve focusing.

3. The large aperture APS-C lens according to claim 1, characterized in that, The second lens group (G2) includes a ninth lens (9), a tenth lens (10), an eleventh lens (11), and a twelfth lens (12) arranged in sequence from the object side to the image side along the optical axis; the ninth lens (9) is a biconcave negative-power lens; the tenth lens (10) is a biconvex positive-power lens; the eleventh lens (11) is a meniscus positive-power lens with the convex surface facing the image side; the twelfth lens (12) is a plano-convex positive-power lens.

4. The large aperture APS-C lens according to claim 3, characterized in that, The third lens group (G3) includes a thirteenth lens (13); the thirteenth lens (13) is a meniscus negative-power lens with the convex surface facing the object side.

5. The large aperture APS-C lens according to claim 4, characterized in that, The fourth lens group (G4) includes a fourteenth lens (14), a fifteenth lens (15), and a sixteenth lens (16) arranged in sequence from the object side to the image side along the optical axis; the fourteenth lens (14) is a biconvex positive-power lens; the fifteenth lens (15) is a biconvex positive-power lens; the sixteenth lens (16) is a biconcave negative-power lens.

6. The large aperture APS-C lens according to claim 5, characterized in that, The adjacent surfaces of the third lens (3) and the fourth lens (4) are glued together; and / or, the adjacent surfaces of the seventh lens (7) and the eighth lens (8) are glued together; the adjacent surfaces of the ninth lens (9) and the tenth lens (10) are glued together; and / or, the adjacent surfaces of the fifteenth lens (15) and the sixteenth lens (16) are glued together.

7. The large aperture APS-C lens according to claim 6, characterized in that, The fifth lens (5), the eleventh lens (11) and the thirteenth lens (13) are all aspherical lenses, while the first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the sixth lens (6), the seventh lens (7), the eighth lens (8), the ninth lens (9), the tenth lens (10), the twelfth lens (12), the fourteenth lens (14), the fifteenth lens (15) and the sixteenth lens (16) are all spherical lenses.

8. The large aperture APS-C lens according to claim 1, characterized in that, The aperture of the large-aperture APS-C lens is less than 1, the large-aperture APS-C lens is a fixed-focus lens, the focal length range of the large-aperture APS-C lens is 15mm-30mm, and the field of view 2ω of the large-aperture APS-C lens is 60°-68°.

9. The large aperture APS-C lens according to claim 1, characterized in that, The total optical length of the large-aperture APS-C lens does not exceed 130mm.

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