Half-frame broadening lens

Abstract

The utility model discloses a half-frame widening lens, which comprises a first spherical lens group, a first cylindrical lens group, a second spherical lens group, a second cylindrical lens group and an aspherical lens group which are sequentially arranged from an object side to an image side, and the focal lengths of all the lens groups meet the following conditional expressions: 1.1 lt; f (1-16) Y / f (1-16) Xlt; 1.6); 0.6 lt; f (2) X / f (1-3) Xlt; 0.9, 0.9; -14 lt; f (4-6) X / f (1-16) Xlt; -9.5; 11 lt; 11 lt; f (14-15) Y / f (1-16) Ylt; -7.5,-7.5; 1lt; f (7-13) X / f (1-16) Xlt; and 1.6. Through the combined use of the cylindrical lens group and the spherical lens group, the focal power is reasonably distributed, so that the lens is compact and small; the spherical lens group corrects the light, and the cylindrical lens group compresses the horizontal light, so that the lens obtains the performances of high resolution, low respiration, low distortion and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to a half-frame zoom lens. Background Art

[0002] With the rapid development of internet technology, taking photos and videos has become an essential part of everyday life for ordinary consumers. In recent years, driven by technologies like 5G, the sharing of videos like vlogs has become increasingly popular, and more and more people are using mobile phones, cameras, and other tools to shoot short videos and micro-films.

[0003] However, the typical shooting ratio on mobile phones, tablets, cameras, and other devices on the market is 16:9, while the ratio for cinematic widescreen videos is 2.4:1. Furthermore, shooting a good micro-film or video requires lenses of different focal lengths to work together, especially close-ups of people, which require a medium-to-long focal length, half-frame zoom lens.

[0004] Existing anamorphic lenses have technical problems such as high price, large size and weight, large breathing effect and inconsistent magnification. Utility Model Content

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the technical problems of the prior art anamorphic lens, such as high price, large volume and weight, large breathing effect and unstable magnification, thereby providing a half-frame anamorphic lens.

[0006] In order to solve the above technical problems, the technical solutions of the present utility model are as follows:

[0007] A half-frame zoom lens comprises a first spherical lens group, a first cylindrical lens group, a second spherical lens group, a second cylindrical lens group, and an aspherical lens group, which are sequentially arranged along an optical path from the object side to the image side.

[0008] The first spherical lens group includes a first lens, a second lens, and a third lens arranged in sequence along the optical path from the object side to the image side, the first lens is a spherical lens with negative optical power, the second lens is a spherical lens with negative optical power, and the third lens is a spherical lens with positive optical power;

[0009] The first cylindrical lens group includes a fourth lens, a fifth lens, and a sixth lens arranged in sequence along the optical path from the object side to the image side, the fourth lens and the fifth lens are both cylindrical lenses with negative optical power, and the sixth lens is a cylindrical lens with positive optical power;

[0010] The second spherical lens group includes a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, a twelfth lens, and a thirteenth lens arranged in sequence along the optical path from the object side to the image side, wherein the seventh lens, the ninth lens, the twelfth lens, and the thirteenth lens are all spherical lenses with positive optical power, and the eighth lens, the tenth lens, and the eleventh lens are all spherical lenses with negative optical power;

[0011] The second cylindrical lens group includes a fourteenth lens and a fifteenth lens arranged in sequence along the optical path from the object side to the image side, the fourteenth lens is a cylindrical lens with positive optical power, and the fifteenth lens is a cylindrical lens with negative optical power;

[0012] The aspheric lens group includes a sixteenth lens, and the sixteenth lens is an aspheric lens;

[0013] The focal length distribution of the first lens to the sixteenth lens satisfies the following relationship:

[0014] 1.1 <f(1~16)Y / f(1~16)X<1.6;

[0015] 0.6 <f(2)X / f(1~3)X<0.9;

[0016] -14 <f(4~6)X / f(1~16)X<-9.5;

[0017] -11 <f(14~15)Y / f(1~16)Y<-7.5;

[0018] 1 <f(7~13)X / f(1~16)X<1.6;

[0019] The curvature direction of the fourth lens is the X direction, and the Y direction is the direction perpendicular to the X direction; f(m~n)Y is the comprehensive optical focal length of the m-th lens to the n-th lens along the Y direction, and f(m~n)X is the comprehensive optical focal length of the m-th lens to the n-th lens along the X direction, m and n are both positive integers, 1≤m <n≤16。

[0020] Furthermore, the second lens moves back and forth to achieve inner focusing, and the aperture position is between the eighth lens and the ninth lens.

[0021] Furthermore, the seventh lens and the eighth lens are glued together to form a double glued spherical lens; the eleventh lens and the twelfth lens are glued together to form a double glued spherical lens.

[0022] Furthermore, the fifth lens and the sixth lens are glued together to form a double cemented cylindrical lens; the fourteenth lens and the fifteenth lens are glued together to form a double cemented cylindrical lens.

[0023] Furthermore, the comprehensive optical focal length of the half-frame zoom lens in the Y direction is within the range of 20-25 mm.

[0024] Furthermore, the zoom ratio range of the half-frame zoom lens is 1.25X to 1.4X, and the magnification ratio remains constant at different object distances.

[0025] Furthermore, the total optical length of the half-frame zoom lens does not exceed 110 mm.

[0026] Furthermore, the aperture of the half-frame zoom lens does not exceed 2.

[0027] Furthermore, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, the thirteenth lens, the fourteenth lens and the fifteenth lens are all optical glass lenses, and the sixteenth lens is an aspherical glass lens.

[0028] This utility model has the following advantages: By combining an X-direction cylindrical lens group with a spherical lens group, optical power is rationally distributed, making the optical structure of the half-frame wide-angle lens more compact and cost-effective. The spherical lens group provides comprehensive correction for light, and the optical properties of the cylindrical lens group are then utilized to "compress" horizontally entering light while maintaining vertical light. This increases the lens's horizontal field of view and ensures performance in the X direction. The Y-direction cylindrical lens group and spherical lens group stabilize performance in the other direction. This achieves a half-frame and high magnification lens. Furthermore, the compact design of the integrated cylindrical and spherical lenses results in a small and lightweight lens, significantly reducing cost. The aspherical lens effectively corrects spherical aberration and astigmatism, improving lens resolution while reducing size and weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is an optical structure diagram of the anamorphic lens in the X direction when the object-image distance is infinite in the embodiment of the present invention;

[0031] Figure 2 This is an optical structure diagram of the half-frame zoom lens in the Y direction when the object-image distance is infinite in the embodiment of the present invention;

[0032] Figure 3 This is a diagram showing the optical field curvature and distortion of the half-frame zoom lens when the object-image distance is at infinity in the embodiment of the present invention;

[0033] Figure 4 This is an optical structure diagram of the half-frame zoom lens in the X direction when the object-image distance is 0.4m in the embodiment of the present invention;

[0034] Figure 5 This is an optical structure diagram of the half-frame zoom lens in the Y direction when the object-image distance is 0.4m in the embodiment of the present invention;

[0035] Figure 6 Graphs showing the optical field curvature and distortion of the half-frame zoom lens when the object-image distance is 0.4m in the embodiment of the present invention.

[0036] Explanation of the accompanying drawings: 100, first spherical lens group; 200, first cylindrical lens group; 300, second spherical lens group; 400, second cylindrical lens group; 500, aspherical 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 DESCRIPTION

[0037] 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.

[0038] 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.

[0039] like Figure 1-6The half-frame zoom lens shown includes a first spherical lens group 100, a first cylindrical lens group 200, a second spherical lens group 300, a second cylindrical lens group 400 and an aspherical lens group 500 arranged in sequence along the optical path from the object side to the image side.

[0040] The first spherical lens group 100 includes a first lens 1, a second lens 2, and a third lens 3 arranged in sequence along the optical path from the object side to the image side; the first lens 1 is a spherical lens with negative optical power, the second lens 2 is a spherical lens with negative optical power, and the third lens 3 is a spherical lens with positive optical power.

[0041] The first cylindrical lens group 200 includes a fourth lens 4, a fifth lens 5, and a sixth lens 6 arranged in sequence along the optical path from the object side to the image side; the fourth lens 4 and the fifth lens 5 are both cylindrical lenses with negative optical power, and the sixth lens 6 is a cylindrical lens with positive optical power.

[0042] The second spherical lens group 300 includes a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, an eleventh lens 11, a twelfth lens 12, and a thirteenth lens 13, which are arranged in sequence along the optical path from the object side to the image side. The seventh lens 7, the ninth lens 9, the twelfth lens 12, and the thirteenth lens 13 are all spherical lenses with positive optical power, and the eighth lens 8, the tenth lens 10, and the eleventh lens 11 are all spherical lenses with negative optical power.

[0043] The second cylindrical lens group 400 includes a fourteenth lens 14 and a fifteenth lens 15 sequentially arranged along the optical path from the object side to the image side; the fourteenth lens 14 is a cylindrical lens with positive optical power, and the fifteenth lens 15 is a cylindrical lens with negative optical power.

[0044] The aspheric lens assembly 500 includes a sixteenth lens 16 , which is an aspheric lens.

[0045] The focal lengths of the first lens 1 to the sixteenth lens 16 are distributed to satisfy the following relationship:

[0046] 1.1 <f(1~16)Y / f(1~16)X<1.6;

[0047] 0.6 <f(2)X / f(1~3)X<0.9;

[0048] -14 <f(4~6)X / f(1~16)X<-9.5;

[0049] -11 <f(14~15)Y / f(1~16)Y<-7.5;

[0050] 1 <f(7~13)X / f(1~16)X<1.6;

[0051] The curvature direction of the fourth lens 4 is the X direction, and the Y direction is the direction perpendicular to the X direction; f(m~n)Y is the comprehensive optical focal length of the m-th lens to the n-th lens along the Y direction, and f(m~n)X is the comprehensive optical focal length of the m-th lens to the n-th lens along the X direction, where m and n are both positive integers, and 1≤m <n≤16。

[0052] This half-frame zoom lens utilizes a combination of an X-direction cylindrical lens group and a spherical lens group to rationally distribute optical power, making the optical structure of the half-frame zoom lens more compact and cost-effective. The spherical lens group provides comprehensive correction for light, and the optical properties of the cylindrical lens group are then used to "compress" horizontal light while maintaining vertical light. This increases the lens' horizontal field of view and ensures performance in the X direction. The Y-direction cylindrical and spherical lens groups stabilize performance in the other direction. This achieves half-frame and high magnification. Furthermore, the compact design of the integrated cylindrical and spherical lenses results in a small and lightweight lens, significantly reducing cost. The aspherical lens effectively corrects spherical aberration and astigmatism, improving resolution while reducing size and weight.

[0053] In this embodiment, the comprehensive optical focal length of the half-frame zoom lens in the Y direction is within the range of 20 to 25 mm, the zoom ratio range is 1.25X to 1.4X, and the magnification ratio remains constant at different object distances. The total optical length does not exceed 110 mm, and the aperture does not exceed 2.

[0054] In this embodiment, the second lens 2 moves back and forth to achieve internal focusing. While the overall length of the lens remains unchanged during adjustment, the back and forth movement of the second lens 2 allows for focusing from an object-image distance of 0.4m to infinity, while also overcoming the technical difficulties of large breathing effects and variable magnification in half-frame zoom lenses.

[0055] In this embodiment, the seventh and eighth lenses 7 and 8 are cemented together to form a doublet spherical lens; the eleventh and twelfth lenses 11 and 12 are cemented together to form a doublet spherical lens. The fifth and sixth lenses 5 and 6 are cemented together to form a doublet cylindrical lens; and the fourteenth and fifteenth lenses 14 and 15 are cemented together to form a doublet cylindrical lens. The doublet spherical lenses are used to correct horizontal and vertical chromatic aberrations of the half-frame zoom lens.

[0056] It should be pointed out that the above-mentioned multiple groups of double-glued spherical lenses are combined by bonding. As an alternative embodiment, based on the concept of the present invention, in order to distinguish it from the present invention, after the above-mentioned combination method is changed, such as bonding, integral molding and other combination methods, and then the shape of the combined lens is adaptively changed, it should also be included in the protection scope of the present invention. For a single lens or two consecutive lenses with the same optical power, a single lens can be disassembled into two or more lenses, and two consecutive lenses with the same sign can be combined into one lens. Such simple transformations of the optical structure of the patent, such as the distribution of the optical power of the transformed lens or lens group, are within the scope of the mathematical relationship expression of the patent. On the basis of this embodiment, changes and replacements of the number and combination of lenses in order to distinguish it from the present invention, without departing from the main idea of ​​the present invention, all fall within the protection scope of the present invention.

[0057] In this embodiment, the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, the tenth lens 10, the eleventh lens 11, the twelfth lens 12, the thirteenth lens 13, the fourteenth lens 14 and the fifteenth lens 15 are all optical glass lenses, and the sixteenth lens 16 is an aspherical glass lens.

[0058] See also Figure 3 As shown in the figure, the field curvature and distortion diagrams of the half-frame wide-angle lens are as follows. As can be seen from the curves in the figure, the field curvature is basically less than ±0.5, ensuring that the image with a large field of view has the same clarity; the distortion is less than 10%, ensuring that the image has a small deformation.

[0059] Reference Figure 4 and Figure 5 By adjusting the second lens 2 in the half-frame zoom lens, the overall length of the half-frame zoom lens remains unchanged, achieving an ultra-close object-image distance of 0.4m. Figure 6 As shown in the figure, the field curvature and distortion diagrams of the anamorphic lens at close object distances can be seen from the curves in the figure. It can be seen that the field curvatures are basically less than ±1, ensuring that the image has the same clarity in a large field of view; the distortion is less than 10%, ensuring that the image image has a small deformation.

[0060] Table 1 below lists the actual parameters of each lens of this embodiment that conform to the above mathematical relationship:

[0061]

[0062] Table 1

[0063] The aspheric coefficients of the sixteenth lens 16 are shown in Table 2:

[0064]

[0065] Table 2

[0066] The half-frame zoom lens provided by this utility model adopts an integrated design, which achieves a small lens size while obtaining excellent cost-effective optical performance such as high resolution, low breathing, low distortion, half-frame, and 1.25X~1.4X high magnification. It can be designed to be compatible with the bayonet mounts of various brands of cameras on the market according to actual usage needs, so as to achieve personalized customization and universal fit.

[0067] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A half-frame zoom lens, characterized in that: The invention comprises a first spherical lens group (100), a first cylindrical lens group (200), a second spherical lens group (300), a second cylindrical lens group (400), and an aspherical lens group (500), which are sequentially arranged along the optical path from the object side to the image side; The first spherical lens group (100) comprises a first lens (1), a second lens (2), and a third lens (3) arranged in sequence along the optical path from the object side to the image side, the first lens (1) being a spherical lens with negative optical power, the second lens (2) being a spherical lens with negative optical power, and the third lens (3) being a spherical lens with positive optical power; The first cylindrical lens group (200) comprises a fourth lens (4), a fifth lens (5), and a sixth lens (6) arranged in sequence along the optical path from the object side to the image side, the fourth lens (4) and the fifth lens (5) are both cylindrical lenses with negative optical power, and the sixth lens (6) is a cylindrical lens with positive optical power; The second spherical lens group (300) comprises a seventh lens (7), an eighth lens (8), a ninth lens (9), a tenth lens (10), an eleventh lens (11), a twelfth lens (12), and a thirteenth lens (13) arranged in sequence along the optical path from the object side to the image side, wherein the seventh lens (7), the ninth lens (9), the twelfth lens (12), and the thirteenth lens (13) are all spherical lenses with positive optical power, and the eighth lens (8), the tenth lens (10), and the eleventh lens (11) are all spherical lenses with negative optical power; The second cylindrical lens group (400) comprises a fourteenth lens (14) and a fifteenth lens (15) arranged in sequence along the optical path from the object side to the image side, the fourteenth lens (14) being a cylindrical lens with positive optical power, and the fifteenth lens (15) being a cylindrical lens with negative optical power; The aspheric lens group (500) includes a sixteenth lens (16), and the sixteenth lens (16) is an aspheric lens; The focal length distribution of the first lens (1) to the sixteenth lens (16) satisfies the following relationship: 1.1 <f(1~16)Y / f(1~16)X<1.6; 0.6 <f(2)X / f(1~3)X<0.9; -14 <f(4~6)X / f(1~16)X<-9.5; -11 <f(14~15)Y / f(1~16)Y<-7.5; 1 <f(7~13)X / f(1~16)X<1.6; Wherein, the curvature direction of the fourth lens (4) is the X direction, and the Y direction is the direction perpendicular to the X direction; f(m~n)Y is the comprehensive optical focal length from the mth lens to the nth lens along the Y direction, and f(m~n)X is the comprehensive optical focal length from the mth lens to the nth lens along the X direction. Both m and n are positive integers, 1≤m <n≤16。 2. The half-frame anamorphic lens according to claim 1, wherein: The second lens (2) moves forward and backward to achieve internal focusing, and the aperture position is between the eighth lens (8) and the ninth lens (9).

3. The half-frame anamorphic lens according to claim 1, wherein: The seventh lens (7) and the eighth lens (8) are glued together to form a double glued spherical lens; the eleventh lens (11) and the twelfth lens (12) are glued together to form a double glued spherical lens.

4. The half-frame anamorphic lens according to claim 1, wherein: The fifth lens (5) and the sixth lens (6) are glued together to form a double-cemented cylindrical lens; the fourteenth lens (14) and the fifteenth lens (15) are glued together to form a double-cemented cylindrical lens.

5. The half-frame anamorphic lens according to claim 1, wherein: The comprehensive optical focal length of the half-frame zoom lens in the Y direction is within the range of 20 to 25 mm.

6. The half-frame anamorphic lens according to claim 1, wherein: The zoom ratio range of the half-frame zoom lens is 1.25X to 1.4X, and the magnification ratio remains constant at different object distances.

7. The half-frame anamorphic lens according to claim 1, wherein: The total optical length of the half-frame zoom lens does not exceed 110 mm.

8. The half-frame anamorphic lens according to claim 1, wherein: The aperture of the half-frame zoom lens does not exceed 2.

9. The half-frame anamorphic lens according to claim 1, wherein: The first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the fifth lens (5), the sixth lens (6), the seventh lens (7), the eighth lens (8), the ninth lens (9), the tenth lens (10), the eleventh lens (11), the twelfth lens (12), the thirteenth lens (13), the fourteenth lens (14) and the fifteenth lens (15) are all optical glass lenses, and the sixteenth lens (16) is an aspherical glass lens.

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