Anamorphic Lens

Abstract

We provide anamorphic lenses that combine cylindrical and spherical lenses. The optical system includes a first spherical lens group, a first cylindrical lens group, a second spherical lens group, a second cylindrical lens group, and a third spherical lens group, which are arranged in this order from the object side to the image side. The focal lengths of all the lens groups are equal to or greater than 1.1.

Description

[Technical field]

[0001] The present application relates to the field of optical lenses, and in particular to anamorphic lenses. [Background technology]

[0002] With the rapid development of Internet technology, photography and video have become an indispensable part of ordinary consumers' lives. In recent years, with the promotion of technologies such as 5G, video sharing such as Vlogs has become more and more common, and more and more people are using mobile phones, cameras and other tools to shoot short videos and micro-films.

[0003] However, in the current mobile phones, tablet computers, cameras and other devices on the market, the general shooting ratio is 16:9, while the ratio of widescreen video with a cinematic feel is 2.4:1. At the same time, good micro-cine or video shooting requires lenses of different focal length sections to work together, especially for close-ups of people, a medium telephoto anamorphic lens is required.

[0004] Conventional anamorphic lenses have technical problems such as high cost, large volume weight, large breathing effect, and inconsistent magnification. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, the technical problem to be solved by the present application is to provide an anamorphic lens by overcoming the technical problems existing in the anamorphic lens in the prior art, such as high cost, large volume weight, large breathing effect, and non-constant magnification. [Means for solving the problem]

[0006] In order to solve the above technical problems, the technical proposal of the present application is as follows:

[0007] an anamorphic lens including a first spherical lens group, a first cylindrical lens group, a second spherical lens group, a second cylindrical lens group, and a third spherical lens group, which are arranged in this order from the object side to the image side along an optical path; the first spherical lens group includes a first lens, a second lens, and a third lens, which are arranged in this order from the object side to the image side along an optical path, the first lens being a spherical lens having a positive refractive power, the second lens being a spherical lens having a negative refractive power, and the third lens being a spherical lens having a negative refractive power; the first cylindrical lens group includes a fourth lens, a fifth lens, and a sixth lens, which are arranged in this order from the object side to the image side along the optical path, the fourth lens and the fifth lens are both cylindrical lenses having negative refractive power, and the sixth lens is a cylindrical lens having positive refractive power, the second spherical lens group includes a seventh lens, an eighth lens, and a ninth lens, which are disposed in this order from the object side to the image side along the optical path, the seventh lens and the ninth lens are both spherical lenses having positive refractive power, and the eighth lens is a spherical lens having negative refractive power, the second cylindrical lens group includes a tenth lens and an eleventh lens which are arranged in this order from the object side to the image side along the optical path, the tenth lens being a cylindrical lens having a positive refractive power, and the eleventh lens being a cylindrical lens having a negative refractive power; the third spherical lens group includes a twelfth lens, a thirteenth lens, a fourteenth lens, a fifteenth lens, and a sixteenth lens, which are arranged in this order from the object side to the image side along the optical path, the twelfth lens and the fourteenth lens are both spherical lenses having negative refractive power, the thirteenth lens and the fifteenth lens are both spherical lenses having positive refractive power, and the sixteenth lens is an aspherical lens having negative refractive power, The distribution of focal lengths of the first lens to the sixteenth lens is as follows: 1.1 <f(1~16)Y / f(1~16)X<1.6、 1.6 < f(3)X / f(1~3)X < 2.4, -8 < f(4~6)X / f(1~16)X < -5.3, -12 < f(10~11)Y / f(9~16)Y < -8, -3.5 < f(12~16)X / f(1~16)X < -2.3, satisfying the relationship, wherein the curvature direction of the fourth lens is the X direction, the Y direction is the direction perpendicular to X, f(m~n)Y is the total optical focal length along the Y direction from the m-th lens to the n-th lens, f(m~n)X is the total optical focal length along the X direction from the m-th lens to the n-th lens, m and n are both positive integers, and 1 ≦ m < n ≦ 16.

[0008] Furthermore, the third lens realizes inner focus by moving back and forth.

[0009] Furthermore, the twelfth lens and the thirteenth lens are joined to each other to form a double-jointed spherical lens, and the fourteenth lens and the fifteenth lens are joined to each other to form a double-jointed spherical lens. The double-jointed spherical lens is used to correct the optical chromatic aberration in the horizontal and vertical directions of the large magnification anamorphic lens.

[0010] Furthermore, the fifth lens and the sixth lens are joined to each other to form a double-jointed cylindrical lens, and the tenth lens and the eleventh lens are joined to each other to form a double-jointed cylindrical lens.

[0011] Furthermore, the total optical focal length of the anamorphic lens in the Y direction is in the range of 30~50 mm.

[0012] Furthermore, the zoom ratio range of the anamorphic lens is 1.25X~1.4X, and for different object distances, the magnification is kept constant.

[0013] Furthermore, the overall optical length of the anamorphic lens does not exceed 150 mm.

[0014] Furthermore, the aperture of the anamorphic lens does not exceed 2.

[0015] Furthermore, the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, ninth lens, tenth lens, eleventh lens, twelfth lens, thirteenth lens, fourteenth lens and fifteenth lens are all optical glass lenses, and the sixteenth lens is an aspheric glass lens. Effect of the Invention

[0016] The technical proposal of this application has the following advantages: The combination of the cylindrical lens group and the spherical lens group in the X direction allows the refractive power to be distributed rationally, making the optical structure of the anamorphic lens more compact and sophisticated, and lowering the cost; the spherical lens group is used to comprehensively correct the light rays; and the optical characteristics of the cylindrical lens group are used to "compress" the light rays entering horizontally, while keeping the light rays entering vertically intact, thereby increasing the horizontal shooting viewing angle of the lens and ensuring the performance in the X direction. Furthermore, the cylindrical lens group and the spherical lens group in the Y direction stabilize the performance in another direction. In this way, the half frame and large magnification of the lens are realized, and the compact design of the cylindrical lens and the spherical lens integrated together makes the lens small in volume, light in mass, and greatly reduces the cost; the aspherical lens can effectively correct the spherical aberration and astigmatism of the lens, improving the resolution of the lens while reducing the volume and weight of the lens. [Brief description of the drawings]

[0017] In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces drawings that need to be used in the embodiments of the present application or the prior art description. It is obvious that the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings based on these drawings without exerting creative efforts. [Figure 1] 3 is a schematic diagram of the optical structure of an anamorphic lens in the X direction when the distance between the object and the image is infinite in an embodiment of the present invention; [Diagram 2] 3 is a diagram showing the optical structure of an anamorphic lens in the Y direction when the distance between the object and the image is infinite in an embodiment of the present invention; [Diagram 3] 4A to 4C are diagrams illustrating optical field curvature and distortion aberration of an anamorphic lens when the distance between an object and an image is infinite in an embodiment of the present invention; [Figure 4] 2 is a diagram of the optical structure of an anamorphic lens in the X direction when the object-to-image distance is 0.5 m in an embodiment of the present invention. [Diagram 5] 2 is a diagram showing the optical structure of an anamorphic lens in the Y direction when the object-to-image distance is 0.5 m in an embodiment of the present invention. [Figure 6] 4 is a graph showing the optical field curvature and distortion aberration of an anamorphic lens when the object-to-image distance is 0.5 m in an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The following clearly and completely describes the technical solution of the present application in conjunction with the drawings, and obviously, the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present application without any creative efforts belong to the protection scope of the present application.

[0019] In the description of this application, it should be explained that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are orientations or positional relationships shown based on the drawings, and are only for facilitating and simplifying the description of this application, and do not indicate or imply that the devices or elements mentioned have a specific orientation and must be configured and operated in a specific orientation, and should not be understood as limiting this application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

[0020] The anamorphic lens shown in Figures 1 to 6 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 a third spherical lens group 500, which are arranged in this order from the object side to the image side along the optical path.

[0021] Here, the first spherical lens group 100 includes a first lens 1, a second lens 2, and a third lens 3, which are arranged in order from the object side to the image side along the optical path, and the first lens 1 is a spherical lens having positive refractive power, the second lens 2 is a spherical lens having negative refractive power, and the third lens 3 is a spherical lens having negative refractive power.

[0022] The first cylindrical lens group 200 includes a fourth lens 4, a fifth lens 5, and a sixth lens 6, which are arranged in that order from the object side to the image side along the optical path, and the fourth lens 4 and the fifth lens 5 are both cylindrical lenses having negative refractive power, and the sixth lens 6 is a cylindrical lens having positive refractive power.

[0023] The second spherical lens group 300 includes a seventh lens 7, an eighth lens 8, and a ninth lens 9, which are arranged in that order from the object side to the image side along the optical path, and the seventh lens 7 and the ninth lens 9 are all spherical lenses having positive refractive power, and the eighth lens 8 is a spherical lens having negative refractive power.

[0024] The second cylindrical lens group 400 includes a tenth lens 10 and an eleventh lens 11 that are sequentially arranged from the object side to the image side along the optical path. The tenth lens 10 is a cylindrical lens having a positive refractive power, and the eleventh lens 11 is a cylindrical lens having a negative refractive power.

[0025] The third spherical lens group 500 includes a twelfth lens 12, a thirteenth lens 13, a fourteenth lens 14, a fifteenth lens 15, and a sixteenth lens 16 that are sequentially arranged from the object side to the image side along the optical path. The twelfth lens 12 and the fourteenth lens 14 are both spherical lenses having a negative refractive power. The thirteenth lens 13 and the fifteenth lens 15 are both spherical lenses having a positive refractive power. The sixteenth lens 16 is an aspherical lens having a negative refractive power.

[0026] The distribution of the focal lengths of the first lens 1 to the sixteenth lens 16 satisfies 1.1 < f(1~16)Y / f(1~16)X < 1.6, 1.6 < f(3)X / f(1~3)X < 2.4, -8 < f(4~6)X / f(1~16)X < -5.3, -12 < f(10~11)Y / f(9~16)Y < -8, -3.5 < f(12~16)X / f(1~16)X < -2.3, where the curvature direction of the fourth lens is the X direction, the Y direction is the direction perpendicular to X, f(m~n)Y is the total optical focal length along the Y direction from the m-th lens to the n-th lens, f(m~n)X is the total optical focal length along the X direction from the m-th lens to the n-th lens, m and n are both positive integers, and 1 ≤ m < n ≤ 16.

[0027] ​In such an anamorphic lens, the cylindrical lens group and the spherical lens group in the X direction are combined and used to distribute the refractive power rationally, making the optical structure of the anamorphic lens more compact and sophisticated, and lowering the cost. The spherical lens group is used to comprehensively correct the light rays, and the optical properties of the cylindrical lens group are used to "compress" the light rays entering horizontally, but keep the light rays entering vertically intact, thereby increasing the horizontal shooting viewing angle of the lens and ensuring the performance in the X direction. Furthermore, the cylindrical lens group and the spherical lens group in the Y direction stabilize the performance in another direction. In this way, the half frame and large magnification of the lens are realized, and the compact design of the cylindrical lens and the spherical lens integrated together makes the lens volume small, the mass light, and the cost significantly reduced. The aspherical lens can effectively correct the spherical aberration and astigmatism of the lens, improving the resolution of the lens while reducing the volume and weight of the lens.

[0028] In this embodiment, the total optical focal length of the anamorphic lens in the Y direction is in the range of 30 to 50 mm. The magnification ratio of the anamorphic lens is in the range of 1.25X to 1.4X, and the magnification is kept constant at different object distances. The total optical length of the anamorphic lens does not exceed 150 mm. The aperture of the anamorphic lens does not exceed 2.

[0029] In this embodiment, the third lens 3 moves back and forth to achieve inner focusing. During adjustment, the overall length of the lens remains the same, and moving the third lens 3 back and forth achieves focusing from an object-to-image distance of 0.65 m to infinity, while overcoming the technical difficulties of the large breathing effect of the anamorphic lens and the non-constant magnification.

[0030] In this embodiment, the twelfth lens 12 and the thirteenth lens 13 are bonded together to form a double-cemented spherical lens. The fourteenth lens 14 and the fifteenth lens 15 are bonded together to form a double-cemented spherical lens. The fifth lens 5 and the sixth lens 6 are bonded together to form a double-cemented cylindrical lens. The tenth lens 10 and the eleventh lens 11 are bonded together to form a double-cemented cylindrical lens. The double-cemented spherical lens is used to correct the optical chromatic aberration in the horizontal and vertical directions of the anamorphic lens.

[0031] It should be noted that the bonding method of the above-mentioned multiple sets of double cemented spherical lenses is adhesive. As an alternative embodiment, according to the concept of this application, after changing the above-mentioned bonding method, a bonding method such as bonding or integral molding is adopted, and the lens shape after bonding is adaptively changed, should also be included in the protection scope of this application. For a single lens or two consecutive lenses with the same refractive power, the single lens may be divided into two or more lenses, or two consecutive lenses with the same refractive power may be integrated into one lens, and such a simple transformation of the optical structure of this patent, for example, the distribution of the refractive power of the transformed lens or lens group is within the mathematical relationship of this patent. In this embodiment, the changes and replacements made to the number of lenses and the combination method to distinguish from this application, all belong to the protection scope of this application, provided that they do not deviate from the gist of this application.

[0032] In the present 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 aspheric glass lens.

[0033] Referring to FIG. 3, it is a diagram of the field curvature and distortion of the anamorphic lens. As can be seen from the curves in the diagram, the field curvature is approximately less than ±0.2, which ensures that the wide-field screen has the same clarity, and the distortion is less than 5%, which ensures that the imaging screen has a relatively small deformation.

[0034] 4 and 5, when the third lens 3 is adjusted in the anamorphic lens, the overall length of the anamorphic lens is kept the same, and the very close object-image distance of the anamorphic lens is realized to be 0.5m. Referring to FIG. 6, it is a diagram of the field curvature and the distortion aberration of the anamorphic lens when the object distance is close, as can be seen from the curves in the diagram, each field curvature is approximately less than ±0.5, which ensures that the wide field screen has the same clarity, and the amount of distortion aberration is less than 10%, which ensures that the image screen has a relatively small deformation.

[0035] Table 1 below lists the actual parameters of each lens in this example that conform to the above mathematical relationships.

[0036] [Table 1]

[0037] The aspheric coefficients of the sixteenth lens 16 are as shown in Table 2 below.

[0038] [Table 2]

[0039] The anamorphic lens of the present application adopts an integrated design, which realizes a small lens volume, while at the same time providing excellent, cost-effective optical performance such as high resolution, low breathing, low distortion aberration, half frame, and high magnification of 1.25X to 1.4X. According to actual usage demand, the engagement port can be designed to be compatible with various brands of cameras on the market, thereby realizing customization and standardization of fit.

[0040] Obviously, the above examples are merely examples for clarity and are not intended to limit the embodiments. Those skilled in the art can make other different types of changes or variations based on the above description. It is not necessary and cannot be possible to cover all the embodiments here. And the obvious changes or variations derived thereby still fall within the scope of protection of the present application. [Explanation of symbols]

[0041] 100, first spherical lens group, 200, first cylindrical lens group, 300, second spherical lens group, 400, second cylindrical lens group, 500, third spherical 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.

Claims

1. The anamorphic lens 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 a third spherical lens group (500), which are arranged in this order from the object side to the image side along an optical path; The first spherical lens group (100) includes a first lens (1), a second lens (2), and a third lens (3) that are arranged in this order from the object side to the image side along the optical path, the first lens (1) being a spherical lens having a positive refractive power, the second lens (2) being a spherical lens having a negative refractive power, and the third lens (3) being a spherical lens having a negative refractive power, The first cylindrical lens group (200) includes a fourth lens (4), a fifth lens (5), and a sixth lens (6) that are arranged in this order from the object side to the image side along the optical path, the fourth lens (4) and the fifth lens (5) are both cylindrical lenses having negative refractive power, and the sixth lens (6) is a cylindrical lens having positive refractive power, the second spherical lens group (300) includes a seventh lens (7), an eighth lens (8), and a ninth lens (9) that are arranged in this order from the object side to the image side along the optical path, the seventh lens (7) and the ninth lens (9) are both spherical lenses having positive refractive power, and the eighth lens (8) is a spherical lens having negative refractive power; the second cylindrical lens group (400) includes a tenth lens (10) and an eleventh lens (11) that are arranged in this order from the object side to the image side along the optical path, the tenth lens (10) being a cylindrical lens having a positive refractive power, and the eleventh lens (11) being a cylindrical lens having a negative refractive power; the third spherical lens group (500) includes 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 this order from the object side to the image side along the optical path, the twelfth lens (12) and the fourteenth lens (14) are both spherical lenses having negative refractive power, the thirteenth lens (13) and the fifteenth lens (15) are both spherical lenses having positive refractive power, and the sixteenth lens (16) is an aspherical lens having negative refractive power; The focal lengths of the first lens (1) to the sixteenth lens (16) are distributed as follows: 1.1<f(1-16)Y / f(1-16)X<1.6, 1.6<f(3)X / f(1-3)X<2.4, -8<f(4~6)X / f(1~16)X<-5.3, -12<f(10~11)Y / f(9~16)Y<-8, The relationship of -3.5<f(12-16)X / f(1-16)X<-2.3 is satisfied. Here, the curvature direction of the fourth lens (4) is the X direction, the Y direction is a direction perpendicular to the X direction, f(m to n)Y is a total optical focal length along the Y direction from the mth lens to the nth lens, f(m to n)X is a total optical focal length along the X direction from the mth lens to the nth lens, m and n are both positive integers, and 1≦m<n≦16.

2. The anamorphic lens according to claim 1, characterized in that the third lens (3) achieves inner focus by moving back and forth.

3. 2. The anamorphic lens of claim 1, wherein the twelfth lens (12) and the thirteenth lens (13) are bonded together to form a double-cemented spherical lens, and the fourteenth lens (14) and the fifteenth lens (15) are bonded together to form a double-cemented spherical lens.

4. 2. The anamorphic lens of claim 1, wherein the fifth lens (5) and the sixth lens (6) are bonded together to form a double-cemented cylindrical lens, and the tenth lens (10) and the eleventh lens (11) are bonded together to form a double-cemented cylindrical lens.

5. The anamorphic lens of claim 1, wherein a total optical focal length of the anamorphic lens in the Y direction is within a range of 30 to 50 mm.

6. 2. The anamorphic lens of claim 1, wherein the magnification ratio of the anamorphic lens ranges from 1.25X to 1.4X, and the magnification is kept constant for different object distances.

7. 2. The anamorphic lens of claim 1, wherein the total optical length of the anamorphic lens does not exceed 150 mm.

8. 2. The anamorphic lens of claim 1, wherein the aperture of the anamorphic lens does not exceed 2.

9. The anamorphic lens of 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 is an aspherical glass lens.

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