Full-frame large-aperture lens

Abstract

The invention discloses a full-frame large-aperture 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:-3.2 < f (G1) / f (G2-G4) <-1.7; -3.4 < f (G3) / f (G2-G4) <-1.9; -3.3 < f (G1) / f <-1.8; f (G4) / f (G2-G4) is greater than 1.3 and less than 2.5. According to the full-frame large-aperture lens, various aberrations of various wave bands are corrected, the central field of view and the edge field of view have enough resolution, the full-frame large-aperture lens has the advantages of being simple in structure, small in size and large in aperture, and the high resolution of imaging of the object distance from infinity to close distance can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and particularly to a full-frame large-aperture lens. Background Art

[0002] In recent years, although the multi-functions of mobile phones have replaced the daily photography of compact cameras, in the view of photography enthusiasts with higher photography requirements, mirrorless cameras can better experience the perfect photography pleasure. Mirrorless cameras have the advantages of small size, light weight, convenient to carry, larger image plane and aperture, etc., and can experience a better background blur effect.

[0003] Existing full-frame large-aperture lenses have problems of various aberrations and low resolution in imaging some wavelength bands. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of various aberrations, low resolution and high cost in imaging some wavelength bands of existing full-frame large-aperture lenses, so as to provide a full-frame large-aperture lens.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows:

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

[0007] -3.2 < f(G1) / f(G2 - G4) < -1.7;

[0008] -3.4 < f(G3) / f(G2 - G4) < -1.9;

[0009] -3.3 < f(G1) / f < -1.8;

[0010] 1.3 < f(G4) / f(G2 - G4) < 2.5;

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

[0012] Further, a diaphragm 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.

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

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

[0015] The second lens is a meniscus positive power lens with the convex surface facing the object side;

[0016] The third lens is a meniscus negative power lens with the convex surface facing the object side;

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

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

[0019] The sixth lens is a biconcave negative power lens;

[0020] The seventh lens is a biconvex positive power lens;

[0021] Wherein, one adjacent surface of the second lens and the third lens is glued together; one adjacent surface of the sixth lens and the seventh lens is glued together.

[0022] Further, the second lens group includes an eighth lens; the eighth lens is a biconvex positive power lens.

[0023] Further, the third lens group includes a ninth lens; the ninth lens is a meniscus negative power lens with the convex surface facing the object side.

[0024] Further, the fourth lens group includes a tenth lens, an eleventh lens, a twelfth lens, a thirteenth lens, a fourteenth lens, a fifteenth lens, and a sixteenth lens arranged in sequence from the object side to the image side along the optical axis;

[0025] The tenth lens is a meniscus negative power lens with the convex surface facing the object side;

[0026] The eleventh lens is a biconvex positive power lens;

[0027] The twelfth lens is a biconvex positive power lens;

[0028] The thirteenth lens is a biconcave positive power lens;

[0029] The fourteenth lens is a meniscus positive power lens;

[0030] The fifteenth lens is a biconvex positive power lens;

[0031] The sixteenth lens is a biconcave lens with positive optical power.

[0032] One adjacent surface of the tenth lens and the eleventh lens is glued together; one adjacent surface of the twelfth lens and the thirteenth lens is glued together; one adjacent surface of the fifteenth lens and the sixteenth lens is glued together.

[0033] Further, the fifth lens, the ninth lens, and the fourteenth lens are all aspherical lenses, and the first lens, the second lens, the third lens, the fourth lens, the sixth lens, the seventh lens, the eighth lens, the tenth lens, the eleventh lens, the twelfth lens, and the thirteenth lens are all spherical lenses.

[0034] Further, the aperture of the full-frame large-aperture lens is 1 - 1.6, and the field angle 2ω of the full-frame large-aperture lens is 55° - 75°.

[0035] Further, the focal length of the full-frame large-aperture lens is 20mm - 40mm.

[0036] Further, the overall optical length of the full-frame large-aperture lens does not exceed 110mm.

[0037] The technical solution of the present invention has the following advantages: This full-frame large-aperture lens corrects various aberrations in each wavelength band, enabling sufficient resolution in both the central and peripheral fields of view. It has the advantages of simple structure, small size, and large aperture, and can achieve high-resolution imaging from infinity to close distances. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is a schematic cross-sectional structure diagram of the full-frame large-aperture lens in the embodiment of the present invention;

[0040] Figure 2 It is the field curvature diagram of the full-frame large-aperture lens in the embodiment of the present invention;

[0041] Figure 3 It is the distortion diagram of the full-frame large-aperture lens in the embodiment of the present invention.

[0042] Description of reference numerals: G1, the first lens group; G2, the second lens group; G3, the third lens group; G4, the fourth lens group; 1, the first lens; 2, the second lens; 3, the third lens; 4, the fourth lens; 5, the fifth lens; 6, the sixth lens; 7, the seventh lens; 8, the eighth lens; 9, the ninth lens; 10, the tenth lens; 11, the eleventh lens; 12, the twelfth lens; 13, the thirteenth lens; 14, the fourteenth lens; 15, the fifteenth lens; 16, the sixteenth lens. Detailed implementation manners

[0043] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0046] As Figure 1 shown, a full-frame large-aperture lens 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:

[0047] -3.2 < f(G1) / f(G2 - G4) < -1.7;

[0048] -3.4 < f(G3) / f(G2 - G4) < -1.9;

[0049] -3.3 < f(G1) / f < -1.8;

[0050] 1.3 < f(G4) / f(G2 - G4) < 2.5;

[0051] Wherein, 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, f(G4) represents the focal length of the fourth lens group G4, and f represents the combined focal length of all lens groups.

[0052] 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, and a seventh lens 7 arranged in sequence along the optical axis from the object side to the image side. Among them, the first lens 1 is a meniscus negative power lens with the convex surface facing the object side, the second lens 2 is a meniscus positive power lens with the convex surface facing the object side, the third lens 3 is a meniscus negative power lens with the convex surface facing the object side, the fourth lens 4 is a meniscus negative power lens with the convex surface facing the image side, the fifth lens 5 is a biconvex positive power lens, the sixth lens 6 is a biconcave negative power lens, and the seventh lens 7 is a biconvex positive power lens.

[0053] The second lens group G2 includes an eighth lens 8, and the eighth lens 8 is a biconvex positive power lens. The third lens group G3 includes a ninth lens 9, and the ninth lens 9 is a meniscus negative power lens with the convex surface facing the object side.

[0054] The fourth lens group G4 includes a tenth lens 10, an eleventh lens 11, a twelfth lens 12, a thirteenth lens 13, a fourteenth lens 14, a fifteenth lens 15, and a sixteenth lens 16 arranged in sequence along the optical axis from the object side to the image side. Among them, the tenth lens 10 is a meniscus negative power lens with the convex surface facing the object side, the eleventh lens 11 is a biconvex positive power lens, the twelfth lens 12 is a biconvex positive power lens, the thirteenth lens 13 is a biconcave positive power lens, the fourteenth lens 14 is a meniscus positive power lens, the fifteenth lens 15 is a biconvex positive power lens, and the sixteenth lens 16 is a biconcave positive power lens.

[0055] In this embodiment, a diaphragm is provided 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. The third lens group G3 has only a single ninth lens 9 for focusing function, and the focusing is more convenient and simple.

[0056] In this embodiment, the fifth lens 5, the ninth lens 9, and the fourteenth lens 14 are all aspherical lenses, and 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 tenth lens 10, the eleventh lens 11, the twelfth lens 12, and the thirteenth lens 13 are all spherical lenses. Such a lens can effectively correct aberrations such as spherical aberration and field curvature, and can reduce the overall weight of the lens.

[0057] In some embodiments, one surface of the second lens 2 adjacent to the third lens 3 is glued together. One surface of the sixth lens 6 adjacent to the seventh lens 7 is glued together. One surface of the tenth lens 10 adjacent to the eleventh lens 11 is glued together. One surface of the twelfth lens 12 adjacent to the thirteenth lens 13 is glued together. One surface of the fifteenth lens 15 adjacent to the sixteenth lens 16 is glued together. The glued lens combination can effectively correct chromatic aberration and make the color of the captured image more realistic.

[0058] In this embodiment, the aperture of the full-frame large-aperture lens is 1 - 1.6, the focal length of the full-frame large-aperture lens is 20 mm - 40 mm. The field angle 2ω of the full-frame large-aperture lens is 55° - 75°. The overall optical length of the full-frame large-aperture lens does not exceed 110 mm.

[0059] Among them, the relevant parameters of each lens are shown in Table 1 below:

[0060]

[0061]

[0062] Table 1

[0063] As Figure 1 shown, in the embodiment of the present invention, the ninth lens 9 can move along the optical axis between the eighth lens 8 and the tenth lens 10 for focusing. Since the ninth lens 9 performs internal focusing, the overall length of the lens can be kept unchanged when the lens adjusts the focal length.

[0064] Such a full-frame large-aperture lens corrects various aberrations in each wavelength band, enabling sufficient resolution in both the central and peripheral fields of view. It has the advantages of simple structure, small size, and large aperture, and can achieve high resolution for imaging from infinity to close distances.

[0065] From Figure 2 and Figure 3 it can be seen that for the full-frame large-aperture lens, the field curvature in the meridional (corresponding to T in Figure 2 ) direction and the sagittal (corresponding to S in Figure 2 ) direction of the light is between -0.2 mm and 0.2 mm; the maximum distortion of the full-frame large-aperture lens is within 2%.

[0066] It should be noted that this full-frame large-aperture lens adopts an integrated design, achieving lens miniaturization while obtaining excellent super cost-effective optical performances such as high resolution, low breathing, and low distortion. It can be designed to match the camera mounts of various brands on the market according to actual usage requirements to achieve personalized customization and compatibility.

[0067] Obviously, the above-mentioned embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A full-frame large aperture 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) which are 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: -3.2<f(G1) / f(G2-G4)<-1.7; -3.4<f(G3) / f(G2-G4)<-1.9; -3.3<f(G1) / f<-1.8; 1.3<f(G4) / f(G2-G4)<2.5; Among them, 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), f(G4) represents the focal length of the fourth lens group (G4), and f represents the combined focal length of all lens groups.

2. The full-frame large aperture lens according to claim 1, characterized in that: An aperture is provided 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 full-frame large aperture lens according to claim 1, characterized in that: The first lens group (G1) comprises a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), and a seventh lens (7) which are arranged in sequence from the object side to the image side along the optical axis; The first lens (1) is a meniscus lens with negative focal power and a convex surface facing the object side; The second lens (2) is a meniscus lens with positive focal power and a convex surface facing the object side; The third lens (3) is a meniscus lens with negative focal power and a convex surface facing the object side; The fourth lens (4) is a meniscus lens with negative focal power and a convex surface facing the image side; The fifth lens (5) is a biconvex positive power lens; The sixth lens (6) is a biconcave lens with negative focal power; The seventh lens (7) is a biconvex positive power lens; Wherein, the adjacent surfaces of the second lens (2) and the third lens (3) are glued together; and the adjacent surfaces of the sixth lens (6) and the seventh lens (7) are glued together.

4. The full-frame large aperture lens according to claim 3, characterized in that: The second lens group (G2) comprises an eighth lens (8); the eighth lens (8) is a biconvex positive power lens.

5. The full-frame large aperture lens according to claim 4, characterized in that: The third lens group (G3) comprises a ninth lens (9); the ninth lens (9) is a meniscus-type negative power lens with a convex surface facing the object side.

6. The full-frame large aperture lens according to claim 5, characterized in that: The fourth lens group (G4) comprises a tenth lens (10), an eleventh lens (11), a twelfth lens (12), a thirteenth lens (13), a fourteenth lens (14), a fifteenth lens (15) and a sixteenth lens (16) which are arranged in sequence from the object side to the image side along the optical axis; The tenth lens (10) is a meniscus lens with negative focal power and a convex surface facing the object side; The eleventh lens (11) is a biconvex positive power lens; The twelfth lens (12) is a biconvex positive power lens; The thirteenth lens (13) is a biconcave positive focal length lens; The fourteenth lens (14) is a meniscus lens with positive focal power; The fifteenth lens (15) is a biconvex positive power lens; The sixteenth lens (16) is a biconcave positive power lens; The adjacent surfaces of the tenth lens (10) and the eleventh lens (11) are glued together; the adjacent surfaces of the twelfth lens (12) and the thirteenth lens (13) are glued together; and the adjacent surfaces of the fifteenth lens (15) and the sixteenth lens (16) are glued together.

7. The full-frame large aperture lens according to claim 6, characterized in that: The fifth lens (5), the ninth lens (9) and the fourteenth lens (14) are all aspherical lenses, and 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 tenth lens (10), the eleventh lens (11), the twelfth lens (12) and the thirteenth lens (13) are all spherical lenses.

8. The full-frame large aperture lens according to claim 1, characterized in that: The aperture of the full-frame large aperture lens is 1-1.6, and the field of view angle 2ω of the full-frame large aperture lens is 55°-75°.

9. The full-frame large aperture lens according to claim 1, characterized in that: The focal length of the full-frame large aperture lens is 20mm-40mm.

10. The full-frame large aperture lens according to claim 1, characterized in that: The total optical length of the full-frame large aperture lens does not exceed 110 mm.

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