Front deformation additional lens and image pickup device

Abstract

The utility model discloses a front deformation additional mirror and an image pickup device. The front deformation additional lens comprises a deformation group and a focusing group which are sequentially arranged from the object side to the image side along the optical axis. The deformation group comprises a first lens with negative focal power, a second lens with positive focal power, a third cylindrical mirror with Y-direction negative focal power and a fourth cylindrical mirror with Y-direction positive focal power which are sequentially arranged from the object side to the image side along the optical axis; the focusing group comprises a fifth cylindrical mirror with Y-direction negative focal power, a sixth cylindrical mirror with Y-direction negative focal power and a seventh cylindrical mirror with Y-direction positive focal power which are sequentially arranged from the object side to the image side along the optical axis; according to the technical scheme, the deformation group and the focusing group are arranged; when deformation is realized, single-time focusing is carried out through the focusing group, aberration accumulation caused by multiple times of focusing is avoided, and better optical performance is realized; and through focal power distribution optimization of each lens, aberration in a full focusing range is ensured to be effectively corrected, and the optical performance is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photography, in particular to a front anamorphic adapter and an image pickup device. BACKGROUND

[0002] With the continuous development of film and photography technology, anamorphic lenses gradually become an important tool for professional photographers and filmmakers due to their unique widescreen effect and artistic expression. Anamorphic lenses can achieve a wider field of view and a unique picture style by compressing the image in the horizontal direction and then stretching it back after shooting. However, traditional anamorphic lenses are expensive, bulky, and have limited compatibility, making it difficult to meet diverse shooting needs. Therefore, as an economical and efficient solution, front anamorphic adapters are gradually favored by the market.

[0003] Front anamorphic adapters convert ordinary lenses into anamorphic lenses by mounting them in front of the main lens, thereby achieving a widescreen effect. However, due to the optical design limitations of the adapter, when combined with the main lens, it often leads to a decrease in image quality, especially in resolution, distortion control, and color restoration. This is a problem that cannot be ignored for professional users who pursue high-quality images. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a front anamorphic adapter and an image pickup device, aiming to solve the problem of poor optical performance caused by the optical design limitations of existing front anamorphic adapters.

[0005] To achieve the above-mentioned purpose, the present application provides a front anamorphic adapter. The front anamorphic adapter includes an anamorphic group and a focusing group arranged in order from the object side to the image side along the optical axis; during focusing, the focusing group moves from the image side to the object side along the optical axis, and the position of the anamorphic group remains unchanged.

[0006] Wherein, the anamorphic group includes a first lens with negative focal power, a second lens with positive focal power, a third cylindrical lens with Y-negative focal power, and a fourth cylindrical lens with Y-positive focal power arranged in order from the object side to the image side along the optical axis; the focusing group includes a fifth cylindrical lens with Y-negative focal power, a sixth cylindrical lens with Y-negative focal power, and a seventh cylindrical lens with Y-positive focal power arranged in order from the object side to the image side along the optical axis; the anamorphic group and the focusing group satisfy the following conditional expressions:

[0007] 1<F1a / F1b<3;

[0008] -3<F2a / F2b<-1;

[0009] 7<Abs(F1G) / Fmain;

[0010] 7 Abs(F2G) / Fmain;

[0011] Wherein, F1a is the focal length of the first lens, F1b is the combined focal length of the third cylindrical lens and the fourth cylindrical lens in Y direction; F2a is the focal length of the fifth cylindrical lens in Y direction, F2b is the combined focal length of the sixth cylindrical lens and the seventh cylindrical lens in Y direction; F1G is the focal length of the anamorphic group, F2G is the focal length of the focusing group, and Fmain is the focal length of the main lens after the front anamorphic additional lens.

[0012] In some embodiments, the anamorphic group has negative optical power; and the focusing group has positive optical power.

[0013] In some embodiments, the second lens is an aspherical lens.

[0014] In some embodiments, the fifth cylindrical lens has an Abbe number Vd≥60.

[0015] In some embodiments, the third cylindrical lens and the fourth cylindrical lens are combined to form a first cemented lens.

[0016] In some embodiments, the third cylindrical lens has an Abbe number Vd3=41.15, and the fourth cylindrical lens has an Abbe number Vd4=23.78.

[0017] In some embodiments, the sixth cylindrical lens and the seventh cylindrical lens are combined to form a second cemented lens.

[0018] In some embodiments, the sixth cylindrical lens has an Abbe number Vd6=28.321, and the seventh cylindrical lens has an Abbe number Vd7=40.802.

[0019] In some embodiments, the second lens, the fourth cylindrical lens, and the seventh cylindrical lens have a refractive index Nd≥1.8.

[0020] The present application also proposes an image pickup device, which comprises an image sensor configured to receive an optical image formed by the front anamorphic additional lens and the front anamorphic additional lens as described above.

[0021] The technical scheme of the present application provides a front deformation additional lens. The front deformation additional lens comprises a deformation group and a focusing group arranged in sequence along an optical axis from an object side to an image side; so that the deformation is realized while single focusing is performed through the focusing group, the problem of aberration accumulation caused by multiple focusing in the traditional scheme is avoided, and good optical performance is achieved. The deformation group and the focusing group have the lens configuration and satisfy the optical power condition as described above; and then the optical power distribution of each lens in the deformation group and the focusing group is optimized to ensure that the aberration in the full focusing range is effectively corrected, and the optical performance is further improved. The present application also provides an image pickup device. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical schemes in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 The structure diagram of the front deformation additional lens in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The technical schemes in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] The present application provides a front deformation additional lens. The front deformation additional lens comprises a deformation group G1 and a focusing group G2 arranged in sequence along an optical axis from an object side to an image side; the deformation group G1 is responsible for realizing the deformation effect of the image, and the focusing group G2 is responsible for realizing the focusing function of the full shooting distance. In the focusing process, the focusing group G2 moves along the optical axis from the image side to the object side, and the position of the deformation group G1 remains unchanged. In this way, the focusing of the full shooting distance is realized through the focusing group G2, the secondary focusing requirement of the rear-attached main lens is avoided, and the operation efficiency is improved; and since the position of the deformation group G1 is fixed and the movement of the focusing group G2 is optimized, the single zoom design can avoid the problem of aberration accumulation caused by multiple focusing in the traditional scheme, and good optical performance is achieved.

[0026] In the specific setting of an embodiment, refer to Figure 1As shown, the deformation group G1 as a whole has negative optical power and can diverge light rays to achieve a specific optical deformation effect. The deformation group G1 includes, in order from the object side to the image side along the optical axis, a first lens L1 having negative optical power, a second lens L2 having positive optical power, a third cylindrical lens L3 having Y-direction negative optical power, and a fourth cylindrical lens L4 having Y-direction positive optical power. Through the lens configuration, the spherical aberration, chromatic aberration and other aberrations in the system can be effectively corrected, and the imaging quality can be improved. Among them, the second lens L2 cooperates with the first lens L1 to adjust the focal length of the entire system, so that the imaging system can adapt to different imaging needs. The Y-direction negative optical power of the third cylindrical lens L3 and the Y-direction positive optical power of the fourth cylindrical lens L4 are designed to make the deformation group G1 achieve a specific deformation effect, such as a wide screen effect, to provide a wider field of view and a more shocking visual effect; the deformation coefficient thereof is set to 1.33X. Further, by modifying the optical power parameter information of the third cylindrical lens L3 and the fourth cylindrical lens L4 in the deformation group G1, the deformation coefficient can be adjusted, and the adjustment range is (1.25-1.33X).

[0027] The focusing group G2 as a whole has positive optical power and can converge light rays to compensate for the change in optical path caused by the deformation group G1. The focusing group G2 includes, in order from the object side to the image side along the optical axis, a fifth cylindrical lens L5 having Y-direction negative optical power, a sixth cylindrical lens L6 having Y-direction negative optical power, and a seventh cylindrical lens L7 having Y-direction positive optical power. The focusing group G2 is used to quickly adjust the focal length to ensure the clarity of the imaging, and in the present embodiment, the focusing group G2 is a combination of cylindrical lenses, which are a kind of aspherical lenses and have one-dimensional magnification or compression function, so that the light rays in the Y direction can be accurately controlled, thereby reducing the aberration caused by lens distortion or image field curvature, and ensuring that the wide screen visual effect simulated by the focusing group G2 is clearly and accurately presented in the final imaging.

[0028] The deformation group G1 and the focusing group G2 in the front deformation additional lens proposed in the above embodiment satisfy the following conditional expressions:

[0029] 1<F1a / F1b<3;

[0030] -3<F2a / F2b<-1;

[0031] 7<Abs(F1G) / Fmain;

[0032] 7<Abs(F2G) / Fmain;

[0033] Wherein, F1a is the focal length of the first lens L1, F1b is the combined focal length of the third cylindrical lens L3 and the fourth cylindrical lens L4 in Y direction; F2a is the Y direction focal length of the fifth cylindrical lens L5, F2b is the combined focal length of the sixth cylindrical lens L6 and the seventh cylindrical lens L7 in Y direction; F1G is the focal length of the deformation group G1, F2G is the focal length of the focusing group G2, and Fmain is the focal length of the main lens after the front deformation additional lens.

[0034] Therefore, the conditions met by each lens in the deformation additional lens are further set to improve the optical performance of the system. Among them, the condition formula (1<F1a / F1b<3) and the condition formula (-3<F2a / F2b<-1) limit the focal length ratio of the lenses in the deformation group G1 and the focusing group G2, which helps to reduce the aberration of the system, especially the spherical aberration and coma, thereby improving the clarity and resolution of the imaging. By precisely controlling the focal length ratio of the lenses, it can ensure that the light rays can be more accurately focused on the image plane after passing through the lens, reducing blur and ghosting phenomenon. And through the condition formula (7<Abs(F1G) / Fmain) and (7<Abs(F2G) / Fmain); ensure that the focal length of the deformation group G1 and the focusing group G2 matches the focal length of the main lens, which can realize high-quality deformation imaging without affecting the performance of the main lens.

[0035] Further, the second lens L2 is an aspherical lens. The design of the aspherical lens helps to further correct aberration, improve imaging quality and optimize optical performance. The surface shape of the aspherical lens is precisely calculated and optimized to ensure that the light rays can be more accurately focused on the image sensor after passing through the lens. In addition, the use of aspherical lenses can effectively reduce the volume and weight of the lens, making the entire optical system more compact and lightweight.

[0036] Further, the Abbe number Vd of the fifth cylindrical lens L5 is greater than or equal to 60. High Abbe number material can reduce the dispersion phenomenon, i.e. the focusing point deviation of light at different wavelengths, thereby improving the color reproduction and clarity of the imaging. Selecting the fifth cylindrical lens L5 with an Abbe number Vd≥60 helps to improve the imaging quality of the entire optical system.

[0037] Further, the third cylindrical lens L3 and the fourth cylindrical lens L4 are combined to form a first cemented lens; the sixth cylindrical lens L6 and the seventh cylindrical lens L7 are combined to form a second cemented lens. The design of the cemented lens can reduce the air gap between the lenses, reduce reflection and scattering in the optical path, further correct aberration, and improve imaging quality. Secondly, the use of the cemented lens can reduce the number of lenses, thereby simplifying the structure of the optical system, reducing the complexity of manufacturing and assembly, and reducing the overall size and weight of the lens, making the optical system more compact and portable. Specifically, the Abbe number Vd3 of the third cylindrical lens L3 is 41.15, and the Abbe number Vd4 of the fourth cylindrical lens L4 is 23.78. The Abbe number Vd6 of the sixth cylindrical lens L6 is 28.321, and the Abbe number Vd7 of the seventh cylindrical lens L7 is 40.802.

[0038] Further, the refractive index Nd of the second lens, the fourth cylindrical lens and the seventh cylindrical lens is greater than or equal to 1.8. High refractive index material (Nd≥1.8) has stronger light deflection ability, which can achieve the required optical effect in a shorter optical path. Thus, the required optical effect is achieved with smaller curvature in the lens system, reducing aberration and shortening the optical path, making the system more compact.

[0039] The optical parameters of each lens in the above lens configuration of the pre-attached lens of the present application are listed as shown in Table 1 and Table 2:

[0040] Table 1

[0041]

[0042]

[0043] Table 2

[0044]

[0045] In the pre-attached lens, the material of each lens is not specifically limited, and in a conventional selection, each lens is made of optical glass.

[0046] The present application also provides an image pickup device. The image pickup device includes an image sensor and a pre-attached lens as above. The image sensor is configured to receive an optical image formed by the pre-attached lens. Wherein the image sensor is a camera.

[0047] The above only describes some or preferred embodiments of the present application, neither the text nor the drawings can limit the scope of protection of the present application, any equivalent structural transformation using the contents of the present application specification and drawings, or direct / indirect application in other related technical fields are included in the scope of protection of the present application.

Claims

1. A front-mounted deformable additional mirror, characterized in that, It includes a deformation group and a focusing group arranged sequentially along the optical axis from the object side to the image side; during focusing, the focusing group moves along the optical axis from the image side to the object side, while the position of the deformation group remains unchanged; The deformation group comprises, along the optical axis from the object side to the image side, a first lens with negative optical power, a second lens with positive optical power, a third cylindrical lens with negative optical power in the Y direction, and a fourth cylindrical lens with positive optical power in the Y direction; the focusing group comprises, along the optical axis from the object side to the image side, a fifth cylindrical lens with negative optical power in the Y direction, a sixth cylindrical lens with negative optical power in the Y direction, and a seventh cylindrical lens with positive optical power in the Y direction; the deformation group and the focusing group satisfy the following condition: 1 <F1a / F1b<3; -3 <F2a / F2b<-1; 7 <Abs(F1G) / Fmain; 7 <Abs(F2G) / Fmain; Wherein, F1a is the focal length of the first lens, F1b is the combined focal length of the third and fourth cylindrical lenses in the Y direction; F2a is the focal length of the fifth cylindrical lens in the Y direction, F2b is the combined focal length of the sixth and seventh cylindrical lenses in the Y direction; F1G is the focal length of the anamorphic group, F2G is the focal length of the focusing group, and Fmain is the focal length of the main lens attached to the front anamorphic lens.

2. The front deformable auxiliary mirror according to claim 1, characterized in that, The deformation group has negative optical power, and the focusing group has positive optical power.

3. The front deformable auxiliary mirror according to claim 1, characterized in that, The second lens is an aspherical lens.

4. The front deformable auxiliary mirror according to claim 1, characterized in that, The Abbe number Vd of the fifth cylindrical mirror is ≥60.

5. The front deformable auxiliary mirror according to claim 1, characterized in that, The third cylindrical mirror and the fourth cylindrical mirror are combined to form a first cemented lens.

6. The front deformable auxiliary mirror according to claim 5, characterized in that, The Abbe number of the third cylindrical mirror is Vd3 = 41.15, and the Abbe number of the fourth cylindrical mirror is Vd4 = 23.

78.

7. The front deformable auxiliary mirror according to claim 1, characterized in that, The sixth cylindrical mirror and the seventh cylindrical mirror are combined to form a second cemented lens.

8. The front deformable auxiliary mirror according to claim 7, characterized in that, The Abbe number of the sixth cylindrical mirror is Vd6 = 28.321, and the Abbe number of the seventh cylindrical mirror is Vd7 = 40.

802.

9. The front deformable auxiliary mirror according to claim 1, characterized in that, The refractive index Nd of the second lens, the fourth cylindrical mirror, and the seventh cylindrical mirror is ≥1.

8.

10. An image acquisition device, characterized in that, It includes an image sensor and a front deformable attachment lens as described in any one of claims 1-9, wherein the image sensor is configured to receive an optical image formed by the front deformable attachment lens.

Images