Deformable lens and camera module

Abstract

The embodiment of the utility model relates to the technical field of optical imaging, and provides a deformable lens and a camera module, the deformable lens comprises a first lens group, a second lens group and a third lens group which are arranged from an object side to an image side, the second lens group comprises a first cylindrical mirror and a second cylindrical mirror which are arranged from the object side to the image side, the length of the first cylindrical mirror extends along a first direction, the length of the second cylindrical mirror extends along a second direction, and the first direction, the second direction and the optical axis of the deformable lens are perpendicular to each other; the first lens group comprises a plurality of lenses, and in the first lens group, a part of the lenses can move relative to the second lens group so as to change the focal length of the deformable lens. The camera lens achieves the purposes of large deformation ratio and miniaturization.

Description

Technical Field

[0001] The present application relates to the field of camera technology, and in particular to a deformable lens and a camera module. Background Art

[0002] For a long time, movie theater screens are mostly 2.4:1, while movie camera module screens are mostly in 4:3 and 16:9 formats. In order to adapt to the theater screen ratio, the format shot by conventional spherical movie lenses needs to be cropped up and down to achieve such an aspect ratio, which will lose a certain amount of effective pixels. Therefore, how to improve the deformation ratio of the anamorphic lens while taking into account the miniaturization design has become an important issue in the industry. Utility Model Content

[0003] The embodiments of the present application provide a deformable lens and a camera module that have both a large deformation ratio and miniaturization.

[0004] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, an embodiment of the present application provides an anamorphic lens, comprising a first lens group, a second lens group, and a third lens group arranged from an object side to an image side, wherein the second lens group comprises a first cylindrical lens and a second cylindrical lens arranged from the object side to the image side, wherein the length of the first cylindrical lens extends along a first direction, and the length of the second cylindrical lens extends along a second direction, and the first direction, the second direction, and the optical axis of the anamorphic lens are perpendicular to each other; the first lens group comprises a plurality of lenses, and a portion of the lenses in the first lens group can be moved relative to the second lens group to change the focal length of the anamorphic lens.

[0006] By arranging a second lens group between the first lens group and the third lens group, the second lens group includes a first cylindrical lens and a second cylindrical lens, and then at least one lens in the first lens group can be moved relative to the second lens group along the optical axis to change the distance between the first lens group and the second lens group, thereby realizing variable magnification and focusing. On this basis, the first cylindrical lens and the second cylindrical lens are vertically staggered in a plane perpendicular to the optical axis. In this way, during the variable magnification and focusing process of the anamorphic lens, the focal length of the anamorphic lens in two directions can be quickly and effectively allocated, which not only realizes a large deformation ratio in two directions, but also reduces the effective optical path of the optical lens, which is conducive to the miniaturization and lightweight of the optical lens.

[0007] In some embodiments, the first lens group has negative optical power, and the third lens group has positive optical power; the first cylindrical mirror has positive optical power, and the second cylindrical mirror has negative optical power.

[0008] By reasonably allocating the focal length of each lens group, light can smoothly transition through each lens group of the anamorphic lens, reducing aberrations, thereby facilitating improved imaging quality.

[0009] In some embodiments, the first lens group has negative optical power, and the third lens group has positive optical power; there are multiple first cylindrical lenses, and the multiple first cylindrical lenses form a first cylindrical lens group, and the first cylindrical lens group has positive optical power.

[0010] Through the above arrangement, the light of the anamorphic lens is smoother in the first direction during the zoom and focusing process, so that the anamorphic lens can better balance the focal length distribution and aberration in the first direction, which is further beneficial to improving the anamorphic ratio and imaging quality.

[0011] In some embodiments, the first lens group has negative optical power, and the third lens group has positive optical power; there are multiple second cylindrical lenses, and the multiple second cylindrical lenses form a second cylindrical lens group, and the second cylindrical lens group has negative optical power.

[0012] Through the above arrangement, the light of the anamorphic lens is smoother in the second direction during the zoom and focusing process, so that the anamorphic lens can better balance the focal length distribution and aberration in the second direction, which can further help improve the deformation ratio and imaging quality.

[0013] In some embodiments, the number of the first cylindrical lenses is 2, wherein the first cylindrical lens close to the first lens group has positive optical focal power, and in the first lens group from the object side to the image side, the lens located at the first position has positive optical focal power, and the lens located at the last position has negative optical focal power.

[0014] Through the above arrangement, the anamorphic lens can better balance the focal length and aberration in the first direction, which can not only further improve the deformation ratio and imaging quality in the first direction, but also help to reduce the total optical length.

[0015] In some embodiments, an aperture stop is disposed between the second lens group and the third lens group.

[0016] Through the above arrangement, an elliptical light spot unique to the anamorphic lens can be formed before and after the shooting focus of the anamorphic lens.

[0017] In some embodiments, the third lens group includes a plurality of the lenses, and the aperture stop is disposed between the plurality of the lenses in the third lens group.

[0018] The above arrangement is more conducive to forming an elliptical light spot unique to the anamorphic lens before and after the shooting focus of the anamorphic lens.

[0019] In some embodiments, the focal length of the lens in the first lens group that moves relative to the second lens group is fc, the focal length of the first cylindrical lens is fxd, and the following relationship is satisfied: 0.8<│fc / fxd│<1.2.

[0020] By reasonably selecting the above ratio, not only can the optical power of the first lens group and the second lens group be well balanced to reduce aberrations, but also the light can be made smoother in the first direction, thereby improving the imaging quality; in addition, it is conducive to the miniaturization design of the optical lens.

[0021] In some embodiments, the focal length of the third lens group is ff, the focal length of the first lens group is fq, the focal length of the anamorphic lens along the first direction is fx, and the following relationship is satisfied:

[0022] 0.6 <ff / fx<1.2;-1.3<fq / ff<-0.8。

[0023] When the anamorphic lens satisfies the above relationship, not only can the anamorphic lens achieve a larger deformation factor in the first direction, but also a large deformation ratio, high imaging quality and miniaturized design can be taken into consideration.

[0024] In some embodiments, the focal length of the anamorphic lens along the first direction is fx, the focal length of the anamorphic lens along the second direction is fy, and the following relationship is satisfied: 1.59 <fx / fy<2.01。

[0025] By reasonably selecting the above ratio, not only can the anamorphic lens achieve a larger deformation ratio, but also the imaging quality is improved.

[0026] In some embodiments, the total optical length of the anamorphic lens is L, the focal length of the anamorphic lens along the first direction is fx, the image height of the anamorphic lens along the second direction is H, and the following relationship is satisfied: 4<(L-0.5fx) / H<7.

[0027] By reasonably selecting the above ratios, the anamorphic lens can take into account both a large deformation ratio and a miniaturized design.

[0028] In a second aspect, an embodiment of the present application provides a camera module, comprising a photosensitive element and the anamorphic lens described in the first aspect, wherein the photosensitive element is disposed on the image side of the anamorphic lens.

[0029] The camera module in the embodiment of the present application has the same technical effect as that achieved by the deformable lens in the first aspect, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of the anamorphic lens provided in Embodiment 1 of the present application at one viewing angle;

[0031] Figure 2 A schematic diagram of the structure of the anamorphic lens provided in Embodiment 1 of the present application at another viewing angle;

[0032] Figure 3 This is the MTF diagram of the anamorphic lens provided in Example 1 of the present application;

[0033] Figure 4 A distortion diagram of the anamorphic lens provided in Example 1 of the present application;

[0034] Figure 5 A schematic diagram of the structure of the anamorphic lens provided in Embodiment 1 of the present application at one viewing angle;

[0035] Figure 6 A schematic diagram of the structure of the anamorphic lens provided in Embodiment 1 of the present application at another viewing angle;

[0036] Figure 7 This is the MTF diagram of the anamorphic lens provided in Example 2 of the present application;

[0037] Figure 8 This is a distortion diagram of the anamorphic lens provided in Example 2 of the present application.

[0038] Among them, the reference numerals in the figure are:

[0039] First lens group G1; second lens group G2; third lens group G3; first lens L1; second lens L2; ​​third lens L3; fourth lens L4; fifth lens L5; sixth lens L6; seventh lens L7; eighth lens L8; ninth lens L9; tenth lens L10; eleventh lens L11; first cylindrical lens group S10; second cylindrical lens group S20; aperture stop STOP. DETAILED DESCRIPTION

[0040] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of the present application are explained and described below.

[0041] Focal power is equal to the difference between the image-side light beam convergence and the object-side light beam convergence. It characterizes the ability of the anamorphic lens to deflect light.

[0042] A lens or lens group with positive optical power has a positive focal length and has the effect of converging light.

[0043] A lens or lens group with negative optical power has a negative focal length and has the effect of diverging light.

[0044] Focal length, also known as focal length, is a measure of the convergence or divergence of light in an anamorphic lens. It refers to the vertical distance from the optical center of a lens or lens group to the focal plane when an infinitely distant scene forms a clear image on the focal plane through the lens or lens group. For a fixed-focus lens, the position of its optical center is fixed; for a telephoto lens, the change of the optical center of the lens brings about a change in the focal length of the lens.

[0045] The focal length of a lens (effective focal length, EFL) refers to the distance from the center of the lens to the focus.

[0046] The composite focal length is the combination of the focal lengths of the individual lenses in the lens group.

[0047] The object side is bounded by the lens. The side where the object is located is called the object side, and the surface of the lens close to the object side is called the object side.

[0048] The image side is bounded by the lens. The side where the image of the object is located is called the image side, and the surface of the lens close to the image side is called the image side.

[0049] The aperture (aperture diaphragm) is a device used to control the amount of light that passes through the lens and enters the photosensitive surface inside the camera body. It is usually inside the lens.

[0050] The imaging plane is located on the image side of all lenses in the anamorphic lens and is the plane on which the image is formed after the light passes through each lens in the anamorphic lens in sequence.

[0051] The optical axis is an axis that passes vertically through the center of the lens. The optical axis of the lens is the axis that passes through the center of each lens of the lens.

[0052] Focus is the point where parallel light rays converge after being refracted by a lens or lens group.

[0053] The Abbe number, or dispersion coefficient, is the difference ratio of the refractive index of an optical material at different wavelengths, representing the degree of dispersion of the material.

[0054] Aberration: The anamorphic lens has the properties of an ideal optical system at the optical axis. The near-axis light emitted from a point on the object intersects the image plane at one point (also known as the optical axis image point). However, the light rays that actually pass through the lens with different apertures are difficult to intersect perfectly at one point, but have a certain deviation from the position of the near-axis image point. These differences are collectively called aberrations.

[0055] Distortion, also known as distortion, is the degree of distortion of the image formed by an optical lens relative to the object itself. Distortion is due to the influence of aperture spherical aberration. The height of the intersection of the main light of different fields of view with the Gaussian image plane after passing through the optical lens is not equal to the ideal image height. The difference between the two is the distortion. Therefore, distortion only changes the imaging position of the off-axis object point on the ideal plane, causing the shape of the image to be distorted, but does not affect the clarity of the image.

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "plurality" means two or more.

[0058] like Figure 1 As shown, in some embodiments, the camera module includes a deformable lens and a photosensitive element, wherein the photosensitive element is located on the image side of the deformable lens, such as Figure 1 On the image plane shown.

[0059] The working principle of the camera module is as follows: the light reflected by the photographed scene generates an optical image through the deformable lens and is projected onto the photosensitive surface of the photosensitive element. The photosensitive element converts the optical image into an electrical signal, namely an analog image signal, and transmits it to the processor.

[0060] Among them, the photosensitive element (also called image sensor) is a semiconductor chip with hundreds of thousands to millions of photodiodes on its surface. When exposed to light, it will generate electric charge. The photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). CCD is made of a highly sensitive semiconductor material that can convert light into electric charge. Charge coupled devices are composed of many photosensitive units, usually in units of millions of pixels. When the surface of the photosensitive element is exposed to light, each photosensitive unit will reflect the charge on the component, and the signals generated by all the photosensitive units are added together to form a complete picture.

[0061] The anamorphic lens mainly uses the refraction principle of the lens to form an image, that is, the light of the scene passes through the anamorphic lens to form a clear image on the focal plane, and the image of the scene is recorded by the photosensitive element located on the focal plane. The above-mentioned anamorphic lens can be, but is not limited to, a photographic lens.

[0062] like Figure 1 and Figure 2 As shown, the embodiment of the present application provides a deformable lens, including a first lens group G1, a second lens group G2 and a third lens group G3 arranged from the object side to the image side, the second lens group G2 includes a first cylindrical lens (such as Figure 1 The X cylindrical mirror S11 and / or the X cylindrical mirror S12 in the embodiment and the second cylindrical mirror (such as Figure 1 Y cylindrical mirror S21 and / or Y cylindrical mirror S22 in the embodiment), the first cylindrical mirror (such as Figure 1 The length of the X cylindrical mirror S11 and the X cylindrical mirror S12 in the first direction extends along the first direction, and the length of the second cylindrical mirror (such as Figure 1 The length of the Y cylindrical mirror S21 and the Y cylindrical mirror S22 in the lens extends along the second direction, and the first direction, the second direction and the optical axis of the anamorphic lens are perpendicular to each other; the first lens group G1 includes a plurality of lenses, and a part of the lenses in the first lens group G1 can be moved relative to the second lens group G2 to change the focal length of the anamorphic lens.

[0063] In order to clearly explain the structure of the anamorphic lens, a coordinate system is established for explanation with the direction of the optical axis of the anamorphic lens as the Z axis, the first direction as the X axis, and the second direction as the Y axis.

[0064] The length of the first cylindrical mirror extends along the first direction, which means that the length direction (height direction) of the first cylindrical mirror is parallel to the first direction.

[0065] The length of the second cylindrical mirror extends along the second direction, which means that the length direction (height direction) of the second cylindrical mirror is parallel to the second direction.

[0066] By arranging the second lens group G2 between the first lens group G1 and the third lens group G3, the second lens group G2 includes a first cylindrical mirror and a second cylindrical mirror, and then at least one lens in the first lens group G1 can be moved relative to the second lens group G2 along the optical axis, so as to change the distance between the first lens group G1 and the second lens group G2, that is, to change the distance between the lens located at the last position in the direction from the object side to the image side in the first lens group G1 and the first cylindrical mirror, so as to adjust the focal length of the anamorphic lens. On this basis, the first cylindrical mirror and the second cylindrical mirror are vertically staggered in a plane perpendicular to the optical axis. In this way, in the process of zooming and focusing of the anamorphic lens, the focal length of the anamorphic lens in two directions can be quickly and effectively allocated, so as to not only achieve a large deformation ratio in two directions, but also reduce the effective optical path of the optical lens, which is conducive to the miniaturization and lightweight of the optical lens.

[0067] like Figure 1 and Figure 2 As shown, in some embodiments, the first lens group G1 has negative power, the third lens group G3 has positive power; the first cylindrical lens (such as Figure 1 The X cylindrical mirror S11 shown in the figure has positive optical power, and the second cylindrical mirror (such as Figure 1 The Y cylindrical mirror S21) shown has negative optical power.

[0068] By reasonably allocating the focal length of each lens group, light can smoothly transition through each lens group of the anamorphic lens, reducing aberrations, thereby facilitating improved imaging quality.

[0069] like Figure 1 and Figure 2 As shown, in some embodiments, the first lens group G1 has negative optical power, and the third lens group G3 has positive optical power; there are multiple first cylindrical lenses, and the multiple first cylindrical lenses form a first cylindrical lens group S10, and the first cylindrical lens group S10 has positive optical power.

[0070] Through the above arrangement, the light of the anamorphic lens is smoother in the first direction during the zoom and focusing process, so that the anamorphic lens can better balance the focal length distribution and aberration in the first direction, which is further beneficial to improving the anamorphic ratio and imaging quality.

[0071] like Figure 1 and Figure 2 As shown, in some embodiments, the first lens group G1 has negative optical power, and the third lens group G3 has positive optical power; there are multiple second cylindrical lenses, and the multiple second cylindrical lenses form a second cylindrical lens group S20, and the second cylindrical lens group S20 has negative optical power.

[0072] Through the above arrangement, the light of the anamorphic lens is smoother in the second direction during the zoom and focusing process, so that the anamorphic lens can better balance the focal length distribution and aberration in the second direction, which can further help improve the deformation ratio and imaging quality.

[0073] like Figure 1 and Figure 2 As shown, in some embodiments, the number of the first cylindrical mirrors is two, namely, X cylindrical mirror S11 and X cylindrical mirror S12, X cylindrical mirror S11 and X cylindrical mirror S12 form a first cylindrical mirror group S10, wherein the first cylindrical mirror (such as X cylindrical mirror S11) close to the first lens group G1 is Figure 1 The X-cylindrical mirror S11 shown in the figure has positive refractive power. In the direction from the object side to the image side in the first lens group G1, the lens located at the first position (such as Figure 1 The first lens L1 shown in the figure has positive optical power, and the lens at the last position (such as Figure 1 The third lens L3) shown has negative refractive power.

[0074] Through the above arrangement, the light can smoothly transition between the first lens group G1 and the second cylindrical lens group S20, so that the focal length and aberration in the first direction can be better balanced, and the deformation ratio and imaging quality in the first direction can be further improved. In addition, the design of the two first cylindrical lenses is conducive to further reducing the total optical length.

[0075] like Figure 1 and Figure 2 As shown, in some embodiments, the number of the second cylindrical mirrors is two, namely, a Y cylindrical mirror S21 and a Y cylindrical mirror S22, and the Y cylindrical mirror S21 and the Y cylindrical mirror S22 form a second cylindrical mirror group S20. In this way, the light can smoothly transition between the first cylindrical mirror group and the third lens group G3, so that the focal length and aberration in the second direction can be better balanced, and the deformation ratio and imaging quality in the second direction can be further improved. In addition, the design of the two second cylindrical mirrors is conducive to further reducing the total optical length.

[0076] like Figure 1 and Figure 2 As shown, in some embodiments, the first lens group G1 includes three lenses, namely a first lens L1, a second lens L2 and a third lens L3, wherein the first lens L1 and the second lens L2 in the first lens group G1 are fixed relative to the optical axis, and the third lens L3 can move to change the distance between the first lens group G1 and the second lens group G2.

[0077] The zoom focusing of the anamorphic lens is achieved by moving the third lens L3. Compared with the overall movement of the first lens group G1, the weight of the moving lens group is reduced, thereby reducing the shaking during the focusing process of the anamorphic lens, which is beneficial to improving the imaging quality.

[0078] In some embodiments, the lens (e.g., Figure 1 The focal length of the third lens L3 is fc, the focal length of the first cylindrical lens is fxd, and the following relationship is satisfied: 0.8<│fc / fxd│<1.2.

[0079] When the above ratio fc / fxd is too large or too small, during the zooming and focusing process of the anamorphic lens, not only will the light transition be abrupt, which is not conducive to the imaging quality, but the total optical length of the anamorphic lens will also be longer.

[0080] By reasonably selecting the above ratio, not only can the optical power of the first lens group G1 and the second lens group G2 be well balanced to reduce aberrations, but also the light can be made smoother in the first direction, thereby improving the imaging quality; in addition, the total optical length of the anamorphic lens is effectively reduced, which is conducive to the miniaturization design of the optical lens.

[0081] Of course, in the first lens group G1 , the first lens L1 may be relatively fixed, and the second lens L2 and the third lens L3 may be movable, or the first lens L1 , the second lens L2 and the third lens L3 may all be movable, which is not specifically limited here.

[0082] In addition, the number of lenses in the first lens group G1 can be 3, or it can be 2, 4, 5,...10,..., etc., and is not specifically limited here.

[0083] like Figure 1 and Figure 2 As shown, in some embodiments, the third lens group G3 includes a plurality of lenses, and an aperture stop is provided between the plurality of lenses in the third lens group G3.

[0084] By setting the aperture between the multiple lenses in the third lens group G3 close to the image side, it is helpful to form an elliptical light spot unique to the anamorphic lens before and after the shooting focus of the anamorphic lens, also called a blurred light spot, so that the blurred effect of the anamorphic lens is better.

[0085] For example, Figure 1 As shown, the third lens group G3 includes 8 lenses, and the aperture is located between the third lens (sixth lens L6) and the fourth lens (seventh lens L7) arranged from the object side to the image side in the third lens group G3. The aperture can be set between other two adjacent lenses in the third lens group G3.

[0086] Of course, the aperture stop may be disposed between the plurality of lenses in the third lens group G3 or between the second lens group G2 and the third lens group G3 , which is not specifically limited here.

[0087] like Figure 1 and Figure 5 As shown, in some embodiments, the third lens group G3 includes a plurality of cemented lenses.

[0088] Through the above arrangement, not only can the chromatic aberration and spherical aberration of the anamorphic lens be eliminated, aberration balance can be achieved, thereby improving the imaging quality, but also the assembly process of the third lens group G3 is reduced, thereby facilitating the assembly of the anamorphic lens.

[0089] For example, Figure 1 As shown, the third lens group G3 includes 8 lenses, including 3 cemented lenses. Figure 5 As shown, the third lens group G3 includes 7 lenses, including 2 cemented lenses.

[0090] Of course, the number of the third lenses is not limited to 7 or 8, and can also be 2, 3, 4, 5,...10, 11...15 or other numbers. The number of cemented lenses is also not limited to 2 or 3.

[0091] In some embodiments, the focal length of the third lens group G3 is ff, the focal length of the first lens group G1 is fq, the focal length of the anamorphic lens along the first direction is fx, and the following relationship is satisfied: 0.6 <ff / fx<1.2;-1.3<fq / ff<-0.8。

[0092] The above two parameters mainly affect the distribution of the optical power of the anamorphic lens, which is beneficial to reduce the deflection angle of light when passing through the anamorphic lens, that is, to make the light smoother, so as to correct the aberration and reduce the tolerance sensitivity, thereby improving the imaging quality and increasing the large deformation ratio. Moreover, the total optical length of the anamorphic lens is reduced, which is conducive to miniaturization design.

[0093] In some embodiments, the focal length of the anamorphic lens along the first direction is fx, the focal length of the anamorphic lens along the second direction is fy, and the following relationship is satisfied: 1.59 <fx / fy<2.01。

[0094] If the above parameters are small, although good imaging performance can be easily obtained, a large deformation ratio cannot be achieved; if the above parameters are large, although a large deformation ratio is achieved, the difficulty of correcting the aberration of the deformation lens is significantly increased, and it is difficult to obtain good imaging performance. At the same time, it is also not suitable for matching the currently popular frame formats.

[0095] By reasonably selecting the above ratio within the above range, the anamorphic lens not only has better optical performance, but also can achieve a large anamorphic ratio. For example, the above anamorphic lens can achieve an anamorphic ratio of 1.8X or 2X. The above anamorphic lens can support the currently popular frame formats, such as 4:3 and 16:9.

[0096] In some embodiments, the total optical length of the anamorphic lens is L, the focal length of the anamorphic lens along the first direction is fx, the image height of the anamorphic lens along the second direction is H, and the following relationship is satisfied: 4<(L-0.5fx) / H<7.

[0097] As long as the above parameters are used to limit the length of the anamorphic lens along the optical axis, if the above parameters are small, although the total optical length of the anamorphic lens is reduced, it is more conducive to reducing the length of the anamorphic lens along the optical axis, but at the same time, it will make it difficult to correct the aberration of the anamorphic lens, resulting in poor imaging quality of the anamorphic lens; if the above parameters are large, although the aberration can be well corrected and the imaging quality is improved, the length of the anamorphic lens along the optical axis will be large, and the volume will be large, which is not conducive to miniaturization design.

[0098] By reasonably selecting the above ratio within the above range, not only can the anamorphic lens have better optical performance, taking into account both a large deformation ratio and high imaging quality, but also the volume of the anamorphic lens is reduced, which is conducive to the miniaturization design of the optical lens.

[0099] Figure 1 and Figure 2 FIG. 1 shows a structural diagram of an anamorphic lens according to Embodiment 1. Figure 1 is a schematic diagram of the structure of the anamorphic lens in the first embodiment in the YOZ plane, Figure 2 FIG. 4 is a schematic diagram of the structure of the anamorphic lens in the first embodiment in the XOZ plane.

[0100] The anamorphic lens includes a first lens group G1, a second lens group G2 and a third lens group G3 arranged from the object side to the image side. The first lens group G1 has positive refractive power, and the third lens group G3 has negative refractive power.

[0101] The first lens group G1 includes a first lens L1, a second lens L2 and a third lens L3 arranged from the object side to the image side.

[0102] Among them, the second lens group G2 includes a first cylindrical lens group S10 composed of an X cylindrical lens S11 and an X cylindrical lens S12 and a second cylindrical lens group S20 composed of a Y cylindrical lens S21 and a Y cylindrical lens S22 arranged from the object side to the image side, the first cylindrical lens group S10 has positive optical power, and the second cylindrical lens group S20 has negative optical power.

[0103] The third lens group G3 includes a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10 and an eleventh lens L11 arranged from the object side to the image side, the fifth lens L5 and the sixth lens L6 are cemented lenses, the seventh lens L7 and the eighth lens L8 are cemented lenses, the tenth lens L10 and the eleventh lens L11 are cemented lenses, and a stop is provided between the sixth lens L6 and the seventh lens L7.

[0104] The first lens L1 and the second lens L2 in the first lens group G1 are fixed relative to the optical axis, and the third lens L3 can move to change the distance between the first lens group G1 and the second lens group G2.

[0105] Table 1a to Table 1d respectively give specific parameter values ​​of each lens of a deformable lens of an optional embodiment in Embodiment 1 of the present application.

[0106] Table 1a

[0107] Surface number Surface type R-Value thickness Refractive Index Abbe number 1 Spherical 253.61 4.8 1.83 42.73 2 Spherical -1321.61 0.15 3 Spherical 115.98 2.3 1.9 31.32 4 Spherical 37.61 13.82 5 Spherical -251.91 1.8 1.9 31.32 6 Spherical 71.69 5.52 7 X-cylinder 60.87 10.33 1.75 52.34 8 X-cylinder -60.87 20.66 9 X-cylinder -34.13 2.3 1.67 32.17 10 X-cylinder Infinity 6.3 11 Y Cylinder -22.02 2.3 1.9 31.32 12 Y Cylinder Infinity 2 13 Y Cylinder Infinity 7.88 1.62 60.37 14 Y Cylinder -25.84 0.62 15 Spherical 54.03 4.93 1.9 31.32 16 Spherical -122.09 0.12 17 Spherical 18.27 4.64 1.9 31.32 18 Spherical 39.62 1.04 1.52 64.2 19 Spherical 11.09 6.33 STOP Spherical Infinity 4.43 21 Spherical -15.41 1 1.81 25.48 22 Spherical 132.02 5.93 1.44 95.1 23 Spherical -14.96 0.12 24 Spherical 22.81 5.25 1.75 52.34 25 Spherical -77.07 1.99 26 Spherical -521.45 1 1.76 26.61 27 Spherical 16.69 1.9 28 Spherical 59.73 2.92 1.75 52.34 29 Spherical -59.73 32.64 Image plane Spherical Infinity

[0108] It should be noted that, in Table 1a, “Surface Number” is the number of each surface arranged in sequence from the object side to the image side, the radius R value is the lens of the corresponding surface number, that is, the curvature radius of the object side surface or the image side surface of the lens corresponding to each surface number at the optical axis, and the “Infinity” of the lens in the “Radius of Curvature” parameter series means that the object side surface or the image side surface of the lens is a plane; the first value of each lens in the “Thickness / Spacing” parameter series is the thickness of the lens on the optical axis, and the second value is the distance from the image side surface of the lens to the object side surface of the next lens on the optical axis; the value of STOP in the “Thickness” parameter series is the distance from the center of the aperture STOP to the object side surface of the next lens (the seventh lens L7) on the optical axis.

[0109] In the first embodiment, the anamorphic lens has fx=32.34 mm, L=155.02 mm, H=25 mm, and FNO=2.08, where FNO is the system aperture F value.

[0110] The parameters of the anamorphic lens in the first embodiment satisfy the relationship shown in Table 1b.

[0111] Table 1b

[0112]

[0113] Note: The following are the explanations of the relationship between the anamorphic lenses in various embodiments:

[0114] f c is the focal length of the lens in the first lens group G1 that moves relative to the second lens group G2, and in this embodiment is the focal length of the third lens L3;

[0115] fxd is the focal length of the first cylindrical mirror;

[0116] fq is the focal length of the first lens group G1;

[0117] ff is the focal length of the third lens group G3;

[0118] fx is the focal length of the anamorphic lens along the first direction (X direction);

[0119] fy is the focal length of the anamorphic lens along the second direction (Y direction);

[0120] L is the total optical length of the anamorphic lens;

[0121] H is the image height of the anamorphic lens.

[0122] The positive and negative conditions of the optical power of each lens in the anamorphic lens in Example 1 are shown in Table 1c.

[0123] Table 1c

[0124]

[0125] It should be noted that the "+" and "-" in Table 1c represent the positive and negative conditions of the optical power of each lens in the anamorphic lens in Example 1. Among them, "+" represents that the lens has a positive optical power; "-" represents that the lens has a negative optical power.

[0126] The concave-convex condition of the object side surface or image side surface of each lens in the anamorphic lens in Example 1 at the optical axis is shown in Table 1d.

[0127] Table 1d

[0128]

[0129] It should be noted that the "++", "+-", "-+", and "--" in Table 1d represent the concave-convex situation of the object side or image side of each lens at the optical axis. Among them, "++" represents that both the object side and the image side of the lens are convex toward the object at the optical axis; "+-" represents that the object side of the lens is convex toward the object at the optical axis, and the image side is convex toward the object at the optical axis, that is, a double convex crescent structure; "-+" represents that the object side of the lens is concave toward the object at the optical axis, and the image side is convex toward the object at the optical axis, that is, a double concave structure; "--" represents that both the object side and the image side of the lens are concave toward the object at the optical axis, "∞-" represents that the object side of the lens is a plane at the optical axis, and the image side is concave toward the object at the optical axis; "-∞" represents that the object side of the lens is concave toward the object at the optical axis, and the image side is a plane at the optical axis. Of course, in addition to the above-mentioned concave and convex conditions, each lens in the anamorphic lens may also include any one or more of "+∞" and "∞+", wherein the object side of the lens represented by "∞+" is a plane at the optical axis, and the image side is convex toward the object at the optical axis; the object side of the lens represented by "+∞" is convex toward the object at the optical axis, and the image side is a plane at the optical axis; no specific limitation is made here.

[0130] Combination Figure 1 and Figure 2The structural diagram of the anamorphic lens in the first embodiment, and the main parameters of the anamorphic lens in the first embodiment given in Tables 1a to 1d satisfy the relationship in Table 1b, and the concave and convex conditions at the optical axis of each lens. The MTF of the anamorphic lens in the first embodiment obtained by simulation is as follows: Figure 3 As shown, and the distortion diagram is as follows Figure 4 shown.

[0131] in: Figure 3 The Modulation Transfer Function (MTF) diagram of the anamorphic lens provided in Example 1 of the present application; the MTF diagram reflects the clarity of the anamorphic lens. The horizontal axis represents the imaging from the imaging center to the edge from left to right, with zero on the far left, which is the center of the lens, and the image on the far right; the vertical axis represents the percentage of the actual clarity restored. It marks the resolution of the anamorphic lens, 1 is an ideal value, without units, and cannot be achieved in reality. The curve can only be infinitely close to 1, but can never be equal to 1.

[0132] Figure 4 This is a distortion diagram of the anamorphic lens provided in Example 1 of the present application. The distortion diagram represents the distortion percentage of the anamorphic lens as the image height changes, wherein the abscissa represents the distortion percentage and the ordinate represents the image height.

[0133] from Figure 3 It can be seen that the anamorphic lens has higher corner contrast and resolution and smaller astigmatism, which means that the anamorphic lens can achieve higher resolution and excellent imaging.

[0134] from Figure 4 It can be seen that the maximum distortion of the anamorphic lens is 10%, which is located at the maximum field of view.

[0135] Figure 5 and Figure 6 The structure diagram of the anamorphic lens of the second embodiment is shown. Figure 5 is a schematic diagram of the structure of the anamorphic lens in the second embodiment in the YOZ plane, Figure 6 FIG. 4 is a schematic diagram of the structure of the anamorphic lens in the second embodiment in the XOZ plane.

[0136] The main differences between the anamorphic lens in the second embodiment and the anamorphic lens in the first embodiment are that the number of the third lens group G3 is one less than that of the third lens group G3 in the first embodiment, the number of the cemented lenses is also one less, the parameters of each lens and the conditions it meets are different, and the concave-convex situation of the object side surface or image side surface of each lens at the optical axis.

[0137] like Figure 5 and Figure 6As shown, the anamorphic lens includes a first lens group G1, a second lens group G2 and a third lens group G3 arranged from the object side to the image side. The first lens group G1 has negative optical power, and the third lens group G3 has positive optical power.

[0138] The first lens group G1 includes a first lens L1, a second lens L2 and a third lens L3 arranged from the object side to the image side.

[0139] Among them, the second lens group G2 includes a first cylindrical lens group S10 composed of an X cylindrical lens S11 and an X cylindrical lens S12 and a second cylindrical lens group S20 composed of a Y cylindrical lens S21 and a Y cylindrical lens S22 arranged from the object side to the image side, the first cylindrical lens group S10 has positive optical power, and the second cylindrical lens group S20 has negative optical power.

[0140] The third lens group G3 includes a fourth lens L4, a fifth lens L5, a sixth lens L6, a seventh lens L7, an eighth lens L8, a ninth lens L9 and a tenth lens L10 arranged from the object side to the image side, the seventh lens L7 and the eighth lens L8 are cemented lenses, the tenth lens L10 and the eleventh lens L11 are cemented lenses, and a stop is provided between the sixth lens L6 and the seventh lens L7.

[0141] Tables 2a to 2d respectively give specific parameter values ​​of each lens of a deformable lens of an optional embodiment in Embodiment 2 of the present application.

[0142] Table 2a

[0143] Surface number Surface type R-Value thickness Refractive Index Abbe number 1 Spherical 446.22 4.51 1.75 52.34 2 Spherical -446.22 0.12 3 Spherical 371.16 2.5 1.76 27.55 4 Spherical 108.81 16.99 5 Spherical -192.63 2 1.9 31.32 6 Spherical 192.63 3.33 7 X-cylinder 80.76 12.43 1.75 52.34 8 X-cylinder -104.93 22.58 9 X-cylinder -45.94 2.85 1.62 36.35 10 X-cylinder Infinily 8.04 11 Y Cylinder -33.71 2.85 1.81 25.48 12 Y Cylinder 359.82 5.63 13 Y Cylinder Infinily 8.28 1.75 52.34 14 Y Cylinder -40.87 0.62 15 Spherical 38.17 7.9 1.9 31.32 16 Spherical Infinily 0.12 17 Spherical 26.19 5.63 1.81 41.02 18 Spherical 56.24 2.1 19 Spherical 521.63 5.82 1.65 33.84 20 Spherical 15.71 4.51 STOP Spherical Infinily 3.25 22 Spherical -29.08 1.06 1.7 30.05 23 Spherical 36.67 6.12 1.44 95.1 24 Spherical -18.46 0.12 25 Spherical 44.24 3.41 1.75 52.34 26 Spherical -64.8 0.82 27 Spherical -31.49 1.36 1.85 23.79 28 Spherical -204.99 33.17 29 Spherical Infinily Image plane Spherical Infinily

[0144] In the second embodiment, the anamorphic lens has fx=74.702 mm, L=168.11 mm, H=25 mm, and FNO=2.082.

[0145] The parameters of the anamorphic lens in the second embodiment satisfy the relationship shown in Table 2b.

[0146] Table 2b

[0147]

[0148] The optical power of each lens of the anamorphic lens in Example 2 is shown in Table 2c.

[0149] Table 2c

[0150]

[0151] The concave-convex condition of the object side surface or image side surface of each lens of the anamorphic lens in Example 2 at the optical axis is shown in Table 2d.

[0152] Table 2d

[0153]

[0154] Combination Figure 5 and Figure 6 The structural diagram of the anamorphic lens in the second embodiment, and the main parameters of the anamorphic lens in the second embodiment given in Tables 2a to 2d satisfy the relationship in Table 2b, and the concave and convex conditions at the optical axis of each lens. The MTF diagram of the anamorphic lens in the second embodiment obtained by simulation is as follows: Figure 7 As shown in the distortion diagram Figure 8 shown.

[0155] from Figure 7 It can be seen that the anamorphic lens has higher corner contrast and resolution and smaller astigmatism, which means that the anamorphic lens can achieve higher resolution and excellent imaging.

[0156] from Figure 8 It can be seen that the maximum distortion of the anamorphic lens is 3%, which is located at the maximum field of view.

[0157] In summary, the anamorphic lens of the present application can achieve a 2X anamorphic ratio and can accommodate currently popular frame formats, such as 4:3 and 16:9, while having the characteristics of a large target surface, high resolution, low distortion, and good image quality.

[0158] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A deformable lens, characterized in that: include: A first lens group, a second lens group, and a third lens group arranged from the object side to the image side; The second lens group includes a first cylindrical lens and a second cylindrical lens arranged from the object side to the image side, the length of the first cylindrical lens extends along a first direction, the length of the second cylindrical lens extends along a second direction, and the first direction, the second direction and the optical axis of the anamorphic lens are perpendicular to each other; The first lens group includes a plurality of lenses, and a portion of the lenses in the first lens group can be moved relative to the second lens group to change the focal length of the anamorphic lens.

2. The anamorphic lens according to claim 1, wherein: The first lens group has negative optical power, and the third lens group has positive optical power; The first cylindrical mirror has positive optical power, and the second cylindrical mirror has negative optical power.

3. The anamorphic lens according to claim 1, wherein: The first lens group has negative optical power, and the third lens group has positive optical power; There are multiple first cylindrical mirrors, and the multiple first cylindrical mirrors form a first cylindrical mirror group, and the first cylindrical mirror group has positive optical power; And / or, there are multiple second cylindrical lenses, the multiple second cylindrical lenses form a second cylindrical lens group, and the second cylindrical lens group has negative optical power.

4. The anamorphic lens according to claim 1, wherein: The number of the first cylindrical mirrors is 2, wherein the first cylindrical mirror close to the first lens group has positive optical focal power, and in the first lens group, in the direction from the object side to the image side, the lens located at the first position has positive optical focal power, and the lens located at the last position has negative optical focal power.

5. The anamorphic lens according to any one of claims 1 to 4, wherein: An aperture is provided between the second lens group and the third lens group; Alternatively, the third lens group includes a plurality of the lenses, and the aperture stop is provided between the plurality of lenses in the third lens group.

6. The anamorphic lens according to any one of claims 1 to 4, wherein: The focal length of the lens in the first lens group that moves relative to the second lens group is fc, the focal length of the first cylindrical mirror is fxd, and the following relationship is satisfied: 0.8<│fc / fxd│<1.

2.

7. The anamorphic lens according to any one of claims 1 to 4, wherein: The focal length of the third lens group is ff, the focal length of the first lens group is fq, the focal length of the deformable lens along the first direction is fx, and the following relationship is satisfied: 0.6 <ff / fx<1.2; -1.3 <fq / ff<-0.8。 8. The anamorphic lens according to any one of claims 1 to 4, wherein: The focal length of the anamorphic lens along the first direction is fx, and the focal length of the anamorphic lens along the second direction is fy, and the following relationship is satisfied: 1.59 <fx / fy<2.01。 9. The anamorphic lens according to any one of claims 1 to 4, wherein: The total optical length of the anamorphic lens is L, the focal length of the anamorphic lens along the first direction is fx, the image height of the anamorphic lens along the second direction is H, and the following relationship is satisfied: 4<(L-0.5fx) / H<7.

10. A camera module, characterized in that: include: The anamorphic lens according to any one of claims 1 to 9; A photosensitive element is arranged on the image side of the anamorphic lens.

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